ELAVL1, or Elav-like RBP 1, is an RNA-binding protein that recognizes AU-rich elements in target messenger RNAs and can influence RNA stability and translation. The study was motivated by evidence that ELAVL1 is frequently overexpressed in human malignancies and has previously been associated with aggressive features of cervical cancer. Its expression in cervical tumors has also been linked in earlier work to stabilization of messenger RNAs encoding proteins such as cyclin B1, TPD52 and HOXC6. The new experiments focused on whether ACVRL1 and CASP14 participate in a previously uncharacterized route through which ELAVL1 influences cervical cancer cells.

Expression analysis showed that ELAVL1 messenger RNA and protein levels were higher in the cervical cancer cell lines SiHa and HeLa than in the non-tumorigenic cervical epithelial cell line HCerEpiC. These comparisons used RT-qPCR and western blot analysis, with three technical replicates from three biological replicates for each cell line. ELAVL1 levels were also higher in cervical cancer tissues than in patient-matched adjacent non-tumor samples. The researchers additionally examined a public gene-expression dataset through TNMplot. In that independent analysis of 14 uterine tumor tissues and 14 paired adjacent normal tissues, ELAVL1 expression was significantly higher in tumor samples, with a reported p value of 0.00695. The experimental and public-dataset results therefore converged on ELAVL1 overexpression in cervical and uterine tumor tissue, although the clinical comparison was limited by its small sample size and did not establish patient outcomes.

Functional experiments in SiHa and HeLa cells indicated that ELAVL1 supports several malignant characteristics. Researchers reduced ELAVL1 expression with small interfering RNA and measured cell growth, migration, invasion and apoptosis. CCK-8 assays showed lower proliferation after knockdown, while wound-healing and Transwell assays showed reduced migration and invasion. For the wound-healing experiments, cells were pretreated with 2 μg/mL mitomycin C to reduce interference from proliferation, and migration was evaluated 48 hours after transfection. Cells with silenced ELAVL1 also had a higher proportion of apoptotic cells in flow-cytometry measurements and increased levels of cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase, or PARP, proteins. In the reciprocal experiment, overexpressing ELAVL1 in SiHa cells increased proliferation, wound closure and invasion. Fluorescence imaging further associated ELAVL1 knockdown with reduced formation of F-actin-rich migratory and invasive protrusions. Together, these observations establish a functional association between ELAVL1 expression and aggressive cell behavior in the two cell-line models, without demonstrating that ELAVL1 alone initiates cervical cancer.

The investigators then used the ENCORI/starBase RNA-binding-protein prediction tool to search for a possible connection between ELAVL1 and ACVRL1. The analysis predicted an ELAVL1-binding site in the ACVRL1 messenger RNA 3′ untranslated region at chromosome 12 position 51922109. An RNA immunoprecipitation followed by quantitative PCR supported physical association between ELAVL1 protein and ACVRL1 RNA: ACVRL1 RNA was enriched in the ELAVL1 immunoprecipitate, while the immunoglobulin G control produced only faint nonspecific signal. In dual-luciferase reporter assays, ELAVL1 knockdown reduced activity from a reporter carrying the wild-type ACVRL1 3′ untranslated region. Altering the predicted binding sequence removed this response, suggesting that the candidate region participates in ELAVL1-dependent regulation. These experiments support a post-transcriptional interaction, although they do not establish the precise biochemical mechanism or whether ACVRL1 messenger RNA stabilization is the only consequence of the binding.

ACVRL1 and CASP14 were also investigated as potential interacting proteins. The study cited previous liquid chromatography–mass spectrometry screening that had identified CASP14 among 11 candidate ACVRL1-interacting proteins, then used AlphaFold3 to predict a possible structural interface between the two proteins. Immunofluorescence imaging showed that ACVRL1 and CASP14 colocalized in the nuclei of SiHa and HeLa cells, with CASP14 stained green and ACVRL1 stained red. These findings offer a structural and cellular basis for examining the pathway, but a predicted interface and spatial overlap alone do not demonstrate direct protein binding or a causal intracellular signaling sequence. The authors therefore tested the proposed regulatory relationships with gene-silencing experiments rather than relying on the imaging results alone.

When ELAVL1 was knocked down in SiHa and HeLa cells, both messenger RNA and protein levels of ACVRL1 and CASP14 decreased. Silencing ACVRL1 reduced CASP14 messenger RNA and protein levels without producing a significant change in ELAVL1 expression. In contrast, reducing CASP14 did not noticeably alter ELAVL1 or ACVRL1 expression. This ordering was consistent with an indirect model in which ELAVL1 acts upstream of ACVRL1, which in turn influences CASP14 abundance. The results do not, however, exclude feedback, intermediary regulators or other target RNAs, and knockdown experiments cannot by themselves establish direct causation for every step of the proposed pathway. The observations were measured in cell cultures, not in patients.

Co-transfection experiments provided functional evidence that ACVRL1 and CASP14 contribute to the phenotypes associated with ELAVL1. In SiHa cells overexpressing ELAVL1, simultaneous knockdown of ACVRL1 partially reversed the increases in proliferation, migration and invasion. Knocking down CASP14 produced similar partial reversals of all three behaviors. Additional flow-cytometry analysis showed that CASP14 depletion increased the proportion of apoptotic cells in SiHa and HeLa cultures relative to their negative controls. Because the downstream interventions only partially offset the ELAVL1 phenotype, the findings also suggest that ELAVL1 influences other targets or regulatory modules. The experiments nevertheless support a measurable contribution from the ACVRL1/CASP14 axis to the cellular effects of ELAVL1 in cervical cancer cells. The study used multiple independent biological replicates for the functional assays, with technical replicates used for selected molecular measurements.

The study extended its findings to an in vivo model using SiHa cells implanted subcutaneously in female nude mice. Ten mice were used for the xenograft experiment, with five assigned to the control condition and five to the ELAVL1-silencing condition. Once tumors had formed, researchers administered either an in vivo control or ELAVL1-targeting small interfering RNA at multiple tumor sites. RT-qPCR analysis showed that ELAVL1 messenger RNA was reduced in treated tumors. Tumor volume was significantly smaller in the ELAVL1-silencing group than in the control group, tumor weight was also significantly lower, and the messenger RNA level of the proliferation marker Ki-67 was reduced. The xenograft result indicates that local ELAVL1 silencing can suppress tumor growth in this particular mouse model. It does not demonstrate that a clinically deliverable ELAVL1 inhibitor would be safe or effective in people, and the subcutaneous xenograft reproduces only part of human cervical cancer biology.

Overall, the experiments support ELAVL1 as a cancer-promoting regulator in HPV-associated cervical cancer cell models and nominate ACVRL1 and CASP14 as components of a possible downstream pathway. SiHa cells are HPV16-positive, while HeLa cells are HPV18-positive, linking the cell models to the high-risk HPV types emphasized in the study. The research connects ELAVL1 binding to the ACVRL1 3′ untranslated region with changes in pathway expression, malignant cell behaviors and reduced tumor growth after knockdown. Important limitations include the small clinical sample, reliance on two cell lines and a mouse xenograft, possible influence from other ELAVL1 targets, and the absence of patient outcomes or clinical intervention data. The findings therefore identify a testable regulatory network and a potential target for further research, but they do not yet establish that manipulating this pathway is a safe or effective cervical cancer treatment in humans.

Subject of Research: Mechanistic study of ELAVL1 regulation and cervical cancer progression through the ACVRL1/CASP14 pathway.

Article Title: ELAVL1 overexpression potentiates cervical cancer malignancy via regulating the ACVRL1/CASP14 pathway

Article References: Liu, J., Wang, J., Gao, Y., Cui, X., Wang, W., Ma, H., Jiao, Y., Xu, J., Hao, J., Xu, Z., Li, L., & Hao, M. (2026). ELAVL1 overexpression potentiates cervical cancer malignancy via regulating the ACVRL1/CASP14 pathway. iScience, 29(11), Article 117956. https://doi.org/10.1016/j.isci.2026.117956

Image Credits: AI Generated

DOI: 10.1016/j.isci.2026.117956

Keywords: ELAVL1, cervical cancer, ACVRL1, CASP14, RNA-binding protein, HPV16, HPV18, cancer cell models, molecular regulation, xenograft tumors, overexpression, potentiates

The hospital-based study included female outpatients who underwent HPV genotyping from 2016 through 2021. HPV prevalence followed a bimodal age distribution, reaching its highest level among participants aged 26–30 years and showing a secondary peak among those aged 61 years or older. HPV16 was the most prevalent high-risk genotype, followed by HPV52, HPV58, HPV53 and HPV51. Because the study recruited patients at one tertiary hospital, the findings characterize the women included in the clinical sample rather than establishing population-representative HPV prevalence across Northwest China.

Persistent infection was assessed in 3,542 patients who returned for follow-up. Of these, 33.75% had persistent HPV infection, with the highest persistence rate recorded among people with mixed high-risk and low-risk HPV infections. HPV positivity was correlated with elevated abnormal rates on thin-prep cytology tests, and nine high-risk HPV genotypes were significantly associated with cytological abnormalities. In the cervical cancer cases included in the analysis, HPV16 accounted for 69.7%. These findings describe statistical associations in the retrospective cohort; they do not establish that a particular HPV genotype caused an individual cervical lesion or cancer.

The study also evaluated associations between HPV infection and bacterial vaginosis, aerobic vaginitis, trichomonal vaginitis, vulvovaginal candidiasis and mixed vaginitis. HPV positivity was positively associated with bacterial vaginosis, trichomoniasis and mixed vaginitis but inversely associated with vulvovaginal candidiasis. The strength and direction of these relationships varied by HPV subtype, indicating that the results differed among viral types. The supplied findings document associations within the analyzed patients and do not show that HPV caused a vaginal disorder or that any vaginal disorder increased HPV risk. Similarly, the reported increase in the proportion of nine-valent-vaccine-covered genotypes with increasing cervical lesion severity describes the distribution of viral genotypes in the cohort, not vaccination uptake or the vaccine’s protective effect.

Subject of Research: HPV epidemiology, cervical lesions and vaginal microecological disorders among female outpatients in Shaanxi Province

Article Title: Epidemiological profile of HPV infection, associations with cervical lesions and vaginal microecological disorders, and nine-valent vaccine coverage in Northwest China: a 6-year retrospective study of 57,035 women

Article References: Li, X., Li, R., Jia, X., Wei, L., Yang, Z., Zhang, T., Li, J., Zhang, Q., Feng, H., Tan, F., Chen, Y., Zeng, L., Pan, Y., Pei, M., & Li, N. (2026). Epidemiological profile of HPV infection, associations with cervical lesions and vaginal microecological disorders, and nine-valent vaccine coverage in Northwest China: a 6-year retrospective study of 57,035 women. Virology Journal. https://doi.org/10.1186/s12985-026-03341-9

Image Credits: AI Generated

DOI: 10.1186/s12985-026-03341-9

Keywords: human papillomavirus, HPV16, cervical lesions, persistent infection, cervical cancer, bacterial vaginosis, trichomoniasis, vulvovaginal candidiasis, nine-valent HPV vaccine, Shaanxi Province, Epidemiological, profile

The trial regimen combined PDS0101, an HPV16 therapeutic peptide cancer vaccine intended to initiate an immune response; PDS01ADC, a tumor-targeting interleukin-12 immunocytokine intended to potentiate that response; and bintrafusp alfa, a bifunctional agent designed to block both programmed cell death ligand 1 (PD-L1) and transforming growth factor beta (TGF-beta). A prior report from trial NCT04287868 described promising clinical activity in patients with advanced HPV16-associated malignancies. The updated analysis examined peripheral immune and serum proteomic measurements in an attempt to identify correlates of clinical response to the combination.

For the proteomic analysis, the investigators surveyed serum proteins and built machine-learning models using data available before therapy or early in the regimen. The reported predictive signals were baseline IL-6 and heme oxygenase 1 concentrations, either used alone or combined with an early change in granzyme B. These models were designed to predict both clinical benefit and the duration of overall survival. Their results show that molecular patterns measured in blood contained outcome-related information in this cohort, but they do not establish that the proteins caused the observed differences in response or survival.

The researchers also conducted a broader survey of the peripheral immunome. Among patients who benefited from treatment, they identified a persistent skewing toward increased ratios of peripheral CD8-positive T cells to myeloid cells. The analysis did not determine whether this cellular pattern produced the better outcomes. It also found a positive association between the frequencies of monocytes and myeloid-derived suppressor cells and serum concentrations of inhibitory biomarkers. According to the authors, that association supplies biological context for the serum-based prediction models by linking measurements of particular circulating cell populations with inhibitory molecular signals.

These findings come from a retrospective study in a cohort of 38 patients with HPV16-positive tumors, and the investigators explicitly called for prospective validation in future clinical studies. The scope of the work was therefore outcome prediction within an already treated trial population, rather than a prospective test of whether clinicians could use serum measurements to select treatment or estimate an individual patient’s survival. The study instead supports further evaluation of minimally invasive molecular measurements obtained before or early in the regimen. Whether the models retain their predictive performance in independent prospective cohorts remains to be determined.

Subject of Research: Serum proteomic prediction of response to combination immunotherapy in advanced HPV16-positive malignancies

Article Title: Baseline and early changes in serum proteomic profiles predict anti-tumor activity in patients with advanced HPV-associated malignancies treated with novel combination immunotherapy

Article References: Goswami, M., Lynch, M. T., Floudas, C. S., Strauss, J., Tsai, Y.-T., Marté, J. L., Gulley, J. L., Schlom, J., & Donahue, R. N. (2026). Baseline and early changes in serum proteomic profiles predict anti-tumor activity in patients with advanced HPV-associated malignancies treated with novel combination immunotherapy. Journal of Experimental & Clinical Cancer Research. https://doi.org/10.1186/s13046-026-03847-8

Image Credits: AI Generated

DOI: 10.1186/s13046-026-03847-8

Keywords: HPV16, cancer immunotherapy, serum proteomics, IL-6, heme oxygenase 1, granzyme B, CD8 T cells, myeloid-derived suppressor cells, bintrafusp alfa, PDS0101, Baseline, early

Cervical cancer remains a leading gynecological malignancy worldwide, and persistent infection with high-risk HPV is its principal cause. Yet the progression from HPV infection to cancer is not a simple one-way street. Chronic inflammation, disruption of the cervical epithelial barrier, and immune modulation caused by other genital pathogens are thought to facilitate the persistence of high-risk HPV and the development of lesions. The Shaanxi study set out to quantify how frequently HPV co-occurs with Chlamydia trachomatis (CT), Ureaplasma urealyticum (UU), Neisseria gonorrhoeae (NG), Mycoplasma hominis (MH), and Mycoplasma genitalium (MG), and to describe how these patterns vary across age groups.

The methodology was straightforward but large in scale. Vaginal swabs were obtained for nucleic acid testing of CT, UU, NG, MH, and MG DNA, while cervical exfoliated cells were subjected to HPV genotyping. Because the analysis was retrospective and descriptive, using anonymized clinical data, the ethics committee waived the requirement for individual informed consent. Detection rates were then calculated for each pathogen, for mixed infections, and for the co-occurrence of HPV genotypes with bacterial and mycoplasmal pathogens across different age strata.

The headline number is striking: the overall HPV infection rate in this population was 21.46 percent, meaning 6,862 of the 31,975 women tested positive for at least one HPV genotype. Genotype distribution followed a pattern that has important implications for vaccine strategy. HPV16 was the most prevalent genotype, followed by HPV58, HPV53, HPV52, and HPV61. This ranking is notable because HPV58 and HPV52, which are covered by the nonavalent vaccine, appear prominently in this Chinese cohort, while HPV53, a partially covered type, also ranks high. Regional differences in genotype prevalence are a key argument for tailoring vaccination and screening programs to local epidemiology rather than relying solely on data from other populations.

The bacterial and mycoplasmal pathogens showed distinctly different age profiles. Infection rates of Neisseria gonorrhoeae and Chlamydia trachomatis were highest in women aged 20 years or younger and declined steadily with age, a pattern consistent with the epidemiology of these classic sexually transmitted bacteria in younger, sexually active populations. Ureaplasma urealyticum infection peaked in the 21 to 30-year age group, the demographic window that typically encompasses peak sexual activity and childbearing. In contrast, Mycoplasma hominis prevalence increased with age and was highest in women over 50, suggesting that MH may behave less like a classic sexually acquired infection and more like an opportunistic colonizer whose detection rises as the vaginal microbiome and hormonal milieu change with age.

Mixed infections accounted for a minority of STI-positive cases, but their composition was informative. The combination of Ureaplasma urealyticum and Mycoplasma hominis was the most common mixed infection, with a detection rate of 2.24 percent, reflecting the high individual prevalence of these genital mycoplasmas. At the other extreme, triple infection with Chlamydia trachomatis, Ureaplasma urealyticum, and Mycoplasma hominis was rare, occurring at a rate of just 0.10 percent. The rarity of triple co-infection suggests that while dual colonization with mycoplasmas is common, the accumulation of multiple distinct pathogens in one patient is constrained, possibly by competitive interactions within the genital tract microbiome or by differences in transmission routes.

The association between HPV and the other pathogens emerged clearly in the genotype-level analysis. The authors report that in Shaanxi Province, women with positive samples for genital tract pathogens CT, UU, MH, MG, or NG had a higher likelihood of carrying HPV16, HPV52, HPV58, or HPV53. This co-occurrence pattern aligns with the cofactor hypothesis: bacterial and mycoplasmal infections may damage the cervical epithelium, provoke inflammatory responses, or alter local immunity in ways that favor the acquisition, persistence, or reactivation of high-risk HPV. Chlamydia trachomatis in particular has been repeatedly implicated in cervical cancer risk in prior literature because it can establish intracellular infections that trigger chronic inflammation without provoking strong protective immunity.

The technical basis of the study deserves attention because it illustrates how modern molecular diagnostics enable this kind of population-level mapping. HPV genotyping from cervical exfoliated cells identifies not just the presence of the virus but its specific genotype, allowing researchers to distinguish between the roughly dozen high-risk types and the many low-risk types that circulate in the population. Nucleic acid amplification testing of vaginal swabs for CT, NG, UU, MH, and MG DNA provides sensitive detection of organisms that are difficult or impossible to culture, particularly Mycoplasma genitalium, which has emerged in recent years as an important cause of pelvic inflammatory disease and is increasingly recognized as a cofactor in HPV persistence. The combination of these two testing platforms on paired specimens from the same patients is what makes co-infection analysis possible at this scale.

The clinical implications of the findings are layered. For screening programs, the high overall HPV prevalence of 21.46 percent in gynecologic outpatients reinforces the value of HPV-based cervical cancer screening, and the prominence of HPV16, 58, 53, and 52 in this population provides a benchmark for evaluating which genotyping panels and vaccines offer the best local coverage. For prevention, the association between bacterial STIs and high-risk HPV genotypes suggests that treating or preventing CT, NG, and genital mycoplasma infections could form part of a broader cervical cancer prevention strategy, not merely a strategy for controlling the STIs themselves. For clinicians, the age-specific patterns offer practical guidance: younger women warrant vigilance for gonorrhea and chlamydia, while older women may harbor Mycoplasma hominis more frequently than classic STI models would predict.

The study also has limitations inherent to its design. As a retrospective, single-center, descriptive analysis of gynecologic outpatients, it captures a clinical population rather than a random community sample, so the prevalence figures may not generalize to all women in Shaanxi or to asymptomatic populations. The cross-sectional nature means that temporal relationships cannot be established; the data show that HPV and other pathogens co-occur more often than expected, but they cannot demonstrate whether bacterial infections precede and promote HPV persistence, whether HPV infection increases susceptibility to bacterial pathogens, or whether both are driven by shared behavioral risk factors. Nevertheless, the sheer sample size of nearly 32,000 women, the systematic genotyping, and the multi-pathogen testing make this one of the most comprehensive regional datasets on HPV and STI co-infection in China, and the authors suggest that these findings can help in developing more effective intervention, prevention, and treatment strategies for sexually transmitted infections in the region.

Subject of Research: Prevalence of HPV and its co-occurrence with common sexually transmitted infections among women in Shaanxi, China

Article Title: Prevalence of HPV and its association with common sexually transmitted infections among women in Shaanxi, China: a cross-sectional study

Article References: Zheng, Y., Bai, J., Li, J., Liu, S., Chen, L., & Wang, G. (2026). Prevalence of HPV and its association with common sexually transmitted infections among women in Shaanxi, China: a cross-sectional study. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14362-8

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14362-8

Keywords: HPV, cervical cancer, sexually transmitted infections, Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Neisseria gonorrhoeae, HPV16, genotype distribution, co-infection, Shaanxi China, cross-sectional study

The team, led by Morgan Williamson, Caleb Boren, Rahul Kumar and Lauren Gollahon, fused the two structural proteins of HPV16 to the two halves of a yellow fluorescent protein called Venus. The technique, known as bimolecular fluorescence complementation or BiFC, splits a fluorescent protein into an N-terminal and a C-terminal fragment, neither of which emits light on its own. When the two fragments are brought together by proteins that interact with each other, the fluorophore reconstitutes and fluoresces. By attaching the C-terminal half of Venus to L1 and the N-terminal half to L2, the researchers ensured that only particles containing both structural proteins would produce a detectable YFP signal, providing a built-in reporter of productive capsid assembly.

A key design challenge was to attach the fluorophore halves without straining the capsid architecture. L1 assembles into pentamers that interlock through conserved disulfide bonds between the residues Cys175 and Cys428, forming an icosahedral shell roughly 50 to 60 nanometers in diameter. The native capsid contains approximately 360 copies of L1 along with 12 to 36 copies of the minor protein L2, which sits between pentamers and slightly tightens the shell. The researchers designed a specialized linker with the sequence HPPAPKED to join the fluorophore fragments to the capsid proteins, and structural predictions generated with AlphaFold2 and visualized in ChimeraX suggested the linker allowed the fluorophore halves to approach closely without obstructing the tertiary and quaternary contacts needed for assembly.

The constructs were built using overlap extension PCR, with the L1 and L2 coding sequences copied from the established p16sheLL expression vector and the Venus fragments taken from standard BiFC plasmids. Notably, the new coding regions were placed under a general CMV promoter rather than the SV40 large T-dependent system used in most published HPV16 VLP protocols, which achieves high plasmid copy numbers only in the specialized 293TT producer cell line. By using ordinary 293T cells instead, the authors argue, the platform becomes accessible to far more laboratories. The change also sidesteps recent concerns about producer cells expressing large T antigen, including the possibility of spontaneous packaging of large T coding sequences and the delivery of oncogenic DNA into healthy cells, a risk the team directly tested and did not observe.

Expression of the fusion proteins matched theoretical predictions. Immunoblotting of transfected 293T cells detected L1 at around 60 kilodaltons and L2 at around 70 kilodaltons, consistent with the calculated molecular weights of the L1-VC155 and L2-VN173 fusion proteins. Flow cytometry tracked the BiFC signal over time and found peak intensity at approximately 72 hours after transfection, when roughly 17.6 percent of the total cell population produced detectable YFP, indicating successful co-uptake of both plasmids and intracellular capsid assembly. Live-cell imaging revealed the same cell swelling that earlier researchers famously described as producer cells filling up like beach balls, and the fluorescent signal was visible across multiple microscope platforms and filter sets, from dedicated YFP filters down to standard FITC channels.

Particles were harvested by alkaline lysis with ammonium sulfate, which allows capsid maturation as disulfide bonds form between L1 subunits over 24 to 36 hours, and then purified on a discontinuous iodixanol density gradient by ultracentrifugation. The BiFC particles banded at the expected position, matching the density of the positive control p16sheLL particles, and transmission electron microscopy confirmed distinctive pentamer formation and icosahedral morphology. Dynamic light scattering placed the particles near 50 nanometers, in agreement with the electron micrographs, and showed less size variance than the conventional construct, which displayed multiple peaks including one near 4,000 nanometers corresponding to large aggregates.

That reduction in aggregation is one of the study’s most practical findings. Conventional L1-only VLPs are notorious for clumping into mega-particle assemblies that complicate purification, measurement, and formulation, and the largest aggregate observed in the control samples spanned a full ten microns, roughly a thousand times the diameter of a single particle. In contrast, no mega-aggregates appeared in the BiFC preparations under either aqueous or dry conditions. The authors suggest that the linker and fluorophore slightly alter the electrostatic and hydrophobic surface interactions that drive mesoscale particles together, yielding more uniform suspensions and potentially a higher fraction of usable particles recovered after purification.

The fluorescent tag also opens a route to sorting. Because particles carrying both L1 and L2 differ from L1-only shells in fluorescence, overall charge, and estimated mass, the authors lay out several strategies for separating them. At physiological pH, BiFC-modified L1 carries a net positive charge of roughly plus 27 compared with minus 3 for unmodified L1, a difference that could be exploited with field-flow fractionation using a charged membrane and crossflow. The added fluorophore mass shifts total particle weight enough that the extreme populations, L1-only shells and fully loaded L1/L2 capsids, become distinguishable by resonant mass measurement, which gauges buoyant mass from the frequency shift of a vibrating resonator. The authors caution that the incremental weight difference per additional L2 molecule remains too small for conventional size-based separation, but the combination of charge, fluorescence, and mass could support high-throughput workflows in future flow virometry systems.

Estimated yields were workable for laboratory use. Counting particles per unit area on electron microscopy grids, the team calculated roughly 33.59 times ten to the seventh particles per milliliter fraction, sufficient to achieve a multiplicity of infection of about 6.7 when dosing cell cultures, within the commonly recommended range of 0.1 to 10. Quality control analyses, including PCR screening of extracted capsid contents with primers for L1, L2, and SV40 large T sequences, found no detectable encapsidated DNA, confirming that the particles are empty shells. This emptiness is an important safety feature for a platform intended to serve as a foundation for packaging therapeutic genes or chemotherapeutic payloads for targeted delivery.

The work remains at an early stage, and several questions are unresolved, including whether L1 and L2 fusion proteins made in separate cells can assemble during cell lysis, and whether the higher relative L2 expression in the new system saturates each particle with fluorophore and boosts per-particle brightness. Immunogenicity and in vivo functionality have yet to be tested. Still, the study establishes that a fluorescently self-reporting HPV16 capsid can be produced correctly, imaged on routine equipment, kept free of contaminating nucleic acid, and maintained in a less aggregated state than the current standard. If further studies confirm its immunological performance, the platform could support both next-generation vaccines aimed at broader cross-type protection through L2 epitopes and precision delivery vehicles that exploit the virus’s natural tropism for the heparan sulfate proteoglycans displayed on disturbed and cancerous cells, bringing together vaccine science, nanotechnology, and cancer therapy around a single glowing shell.

Subject of Research: Fluorescently tagged HPV16 virus-like particles engineered for real-time assembly monitoring, reduced aggregation, and potential particle sorting

Article Title: A novel approach to HPV16 VLP construction and production with improved accessibility and particle sorting potential

Article References: Williamson, M., Boren, C., Kumar, R., & Gollahon, L. (2026). A novel approach to HPV16 VLP construction and production with improved accessibility and particle sorting potential. Frontiers in Molecular Medicine, 6, Article 1941186. https://doi.org/10.3389/fmmed.2026.1941186

Image Credits: AI Generated

DOI: 10.3389/fmmed.2026.1941186

Keywords: HPV16, virus-like particles, BiFC, Venus fluorophore, L1 capsid protein, L2 capsid protein, nanoparticle characterization, aggregation, flow virometry, vaccine platform, drug delivery, 293T cells

The logic behind targeting E5 and E6 rests on their central position in HPV-mediated malignant transformation. According to the review, these oncoproteins collectively promote cell proliferation, immune evasion, resistance to apoptosis, and genomic instability, the four pillars on which a virus-infected cell can progress toward cancer. E5 contributes to tumor progression by modulating growth factor signaling and promoting cell survival, effectively creating a cellular environment in which abnormal proliferation is favored. E6, by contrast, plays the more notorious role: it drives malignant transformation primarily by tagging the tumor suppressor p53 for degradation, thereby removing one of the cell’s most important safeguards against uncontrolled division and DNA damage.

The significance of p53 degradation cannot be overstated. In normal cells, p53 acts as a guardian of the genome, halting the cell cycle when DNA damage is detected and triggering programmed cell death when the damage is irreparable. When HPV16 E6 orchestrates the destruction of p53, infected cells lose this critical checkpoint and accumulate mutations with impunity. Because this mechanism is virus-encoded rather than a mutation in the host genome itself, it presents an attractive therapeutic window: a treatment that silences E6 could, in principle, allow p53 function to be restored in tumor cells while leaving normal cells untouched. This selectivity is precisely what makes HPV oncogenes such compelling drug targets compared with conventional cytotoxic approaches.

E5, though less studied than E6, is far from a bystander in the carcinogenic process. The review emphasizes that E5’s modulation of growth factor signaling and its promotion of cell survival help sustain tumor growth and progression. By interfering with normal growth regulatory pathways, E5 helps create conditions in which cells proliferate even in the absence of appropriate external signals. It also contributes to the ability of infected cells to evade immune surveillance, a hallmark of cancer that allows premalignant lesions to persist and progress undetected. A therapeutic strategy that addresses both E5 and E6 simultaneously could therefore attack the disease from multiple angles at once, undermining both the survival signaling and the tumor suppressor evasion that sustain the malignancy.

The technological core of the review concerns two families of gene-silencing tools. The first is built on small interfering RNAs, or siRNAs, short double-stranded RNA molecules that exploit a natural cellular pathway to degrade messenger RNA in a sequence-specific manner. When designed to match sequences within the E5 or E6 transcripts, siRNAs can direct the cellular RNA interference machinery to destroy the viral messages before they are translated into protein, effectively silencing the oncogenes at the post-transcriptional level. The second family comprises CRISPR/Cas-based genome-editing systems, which go a step further by introducing targeted disruptions into the viral DNA itself, potentially knocking out the oncogene sequences permanently rather than merely dampening their expression.

According to the review, both approaches have demonstrated significant potential in preclinical studies. Suppressing E5 and E6 expression has been shown to restore tumor suppressor functions, induce apoptosis in cancer cells, and enhance the sensitivity of those cells to conventional therapies such as chemotherapy and radiotherapy. This last point carries particular clinical weight. Cervical cancer treatment currently relies on surgery, radiation, and cytotoxic drugs, modalities that are effective but blunt and often accompanied by substantial toxicity. If gene-silencing can sensitize tumor cells to existing treatments, lower doses might achieve the same effect, reducing side effects while improving outcomes. The restoration of p53-mediated apoptosis following E6 silencing offers a mechanistically coherent explanation for these observations: cells that regain the ability to die on cue are inherently more vulnerable to DNA-damaging therapies.

The appeal of targeting viral oncogenes rather than host genes also extends to specificity. Because E5 and E6 exist only in HPV-infected cells, therapies directed against their transcripts or coding sequences should, in theory, spare uninfected tissue entirely. This stands in sharp contrast to most anticancer agents, which discriminate between tumor and normal cells only imperfectly. The review frames this viral specificity as a foundational advantage of the gene-silencing paradigm in HPV-driven cancers, one that aligns with the broader movement toward precision oncology in which molecular definitions of disease replace anatomical ones.

Yet the path from laboratory promise to clinical reality is far from straightforward, and the authors devote considerable attention to the challenges that remain. Delivering siRNAs or CRISPR components efficiently and selectively to cervical tumor cells is a formidable obstacle; RNA molecules are rapidly degraded in the bloodstream and do not cross cell membranes unaided, while gene-editing systems require delivery vectors whose safety and tropism must be carefully controlled. Off-target effects, in which silencing or editing tools act on unintended sequences, represent another safety concern that must be rigorously addressed. The review also highlights the inherent limitations of current preclinical models, which may not fully recapitulate the complexity of human cervical carcinogenesis, and notes that therapeutic limitations and unresolved questions still separate these experimental approaches from approved treatments.

Despite these hurdles, the therapeutic perspectives outlined in the review are notably optimistic. The authors position targeted molecular approaches against HPV oncogenes as a frontier for both the prevention and treatment of cervical cancer, complementing rather than replacing existing interventions. Prophylactic HPV vaccines have transformed prevention efforts worldwide, but they do not treat established infections or existing lesions, and a large population of women worldwide carries persistent infections that vaccines cannot address. Therapeutic gene silencing fills precisely this gap, offering a potential intervention for individuals whose disease is already established. The combination of vaccination for prevention and oncogene-directed silencing for treatment could, in principle, cover the entire spectrum of HPV-associated disease.

The review, which was supported by the Infectious and Tropical Diseases Research Center at Tabriz University of Medical Sciences, ultimately serves as both a status report and a roadmap. It consolidates the mechanistic case that E5 and E6 are pivotal to HPV16-driven carcinogenesis, catalogs the preclinical evidence that siRNA and CRISPR/Cas systems can suppress their expression with meaningful biological consequences, and candidly maps the delivery, safety, and translational challenges that stand between the laboratory and the clinic. As gene-silencing technologies mature and delivery platforms improve, the prospect of a therapy that disarms the very genes the virus uses to cause cancer moves from theoretical appeal toward practical possibility, offering hope for a future in which cervical cancer is not only preventable by vaccine but also treatable at its viral roots.

Subject of Research: Gene-silencing strategies targeting HPV16 E5 and E6 oncoproteins for cervical cancer therapy

Article Title: Targeting HPV16 E5 and E6 through gene-silencing approaches: mechanisms, preclinical evidence, and therapeutic perspectives

Article References: Ravanlo, Z. Z., Gholami, S., Rahimi, S. B., Shamekh, A., Adli, A. H., & Baghi, H. B. (2026). Targeting HPV16 E5 and E6 through gene-silencing approaches: mechanisms, preclinical evidence, and therapeutic perspectives. Virology Journal. https://doi.org/10.1186/s12985-026-03321-z

Image Credits: AI Generated

DOI: 10.1186/s12985-026-03321-z

Keywords: HPV16, E5 oncoprotein, E6 oncoprotein, gene silencing, siRNA, CRISPR/Cas9, cervical cancer, p53, oncogenes, virology, RNA interference, gene therapy

The biological logic underlying these findings is straightforward but worth restating. HPV vaccines are prophylactic: they prevent new infection with vaccine-covered oncogenic types, chiefly HPV16 and HPV18, but they do not treat infection that is already established or lesions that already exist. Maximum impact is therefore expected when vaccination is delivered before any sexual exposure to the virus. This principle explains the consistent age gradient seen across national studies, in which protection is strongest among women vaccinated in early adolescence and weaker or less precise among those vaccinated later through catch-up programmes. The causal sequence runs from reduced vaccine-type infection, to fewer persistent infections, to fewer high-grade cervical precancerous lesions classified as CIN2+ or CIN3, to fewer invasive cancers, and ultimately to fewer deaths.

Before mortality data existed, each link in that chain had already been forged. Surveillance in the United States documented declines in vaccine-type HPV prevalence among females aged 14 to 19 within several years of vaccine introduction, with continued reductions and evidence of herd protection in subsequent analyses. A landmark meta-analysis by Drolet and colleagues demonstrated substantial population-level reductions in HPV16/18 infection, anogenital warts, and CIN2+ after vaccination programmes were implemented, particularly where coverage was high and multiple age cohorts were vaccinated. National registry studies then moved the endpoint to invasive cancer itself: in Sweden, quadrivalent vaccination was associated with sharply lower cervical cancer risk, strongest among women vaccinated before age 17; Danish data showed high effectiveness among those vaccinated before age 20; English register-based studies found large reductions in cervical cancer and CIN3, greatest in cohorts offered routine vaccination at ages 12 to 13, with benefits extending across socioeconomic groups; and Scotland reported no invasive cervical cancer cases among women immunized at ages 12 to 13.

The new mortality milestone comes from Sasieni and Falcaro, who analyzed population-based cervical cancer mortality in England from 2001 through 2024 among women aged 20 to 24, 25 to 29, and 30 to 34 years. Vaccination coverage by birth cohort was drawn from official reports, and Poisson regression was applied to death counts to estimate the reduction associated with vaccination compared with a modeled counterfactual based on historical mortality patterns, assuming no herd immunity. The most highly vaccinated routine cohort, women aged 20 to 24 in 2020 to 2024, produced the strongest mortality signal, with zero observed deaths. Earlier catch-up cohorts also showed substantial reductions at ages 20 to 24 and 25 to 29, while the estimate at ages 30 to 34 was considerably less precise. This gradient is biologically coherent: the youngest cohorts were vaccinated earliest, at the highest coverage, and were least likely to have been exposed to oncogenic HPV before immunization.

The authors of the review are careful to appraise the England study critically rather than celebrate it uncritically. Its strengths are considerable: national population coverage, long-term mortality ascertainment, a birth-cohort framework, temporal alignment with the 2008 vaccination programme, and results that fit seamlessly with the earlier reductions in infection, CIN3, and invasive cancer. The principal limitation, however, is the modeled counterfactual. Expected deaths were extrapolated from historical pre-vaccination mortality patterns rather than observed in a contemporaneous unvaccinated control group, so secular changes in screening, diagnostics, treatment, or death certification could in principle influence the trends. Such confounding is unlikely to be fully eliminated in any observational design, even when the timing and birth-cohort pattern align with vaccination.

A second and subtler limitation concerns the very small absolute number of deaths at young ages. In the most protected cohort, the modeled counterfactual amounted to only a few dozen deaths over five years. With zero observed deaths, the point estimate for relative reduction necessarily reaches 100 percent, regardless of whether the true underlying mortality rate is exactly zero or merely very low. The absolute comparison and its confidence interval are therefore more informative than the headline percentage. The absence of deaths is clinically striking, but it should not be read as proof that an individual vaccinated woman has zero risk of dying from cervical cancer. Nor does the study provide individual-level causal inference: vaccination status, screening history, HPV exposure, socioeconomic factors, and treatment pathways were not jointly linked for every death, so the findings support a programme-level conclusion rather than a personal risk estimate.

Screening context adds important nuance to the interpretation. The English cervical screening programme targets ages 25 to 64, with first invitations issued from age 24 years and 6 months, so screening exposure in the 20-to-24-year mortality group was limited to the oldest fraction of that band. This makes screening an unlikely explanation for the mortality pattern in the youngest cohort. For women aged 25 and older, however, screening is a potential co-determinant of mortality that must remain part of the picture. National coverage at 31 March 2024 stood at 68.8 percent among those aged 25 to 64 and 66.1 percent among those aged 25 to 49, with the lowest coverage in the 25-to-29-year subgroup, and the mortality analysis did not directly adjust for individual screening participation. Vaccination remains the most coherent explanation for the birth-cohort gradient, but screening and treatment should be regarded as complementary contributors rather than ignored confounders.

The review also emphasizes that the England results are as much a triumph of programme delivery as of vaccine efficacy. The routine cohorts that generated the strongest mortality effect had adolescent coverage of roughly 88 to 90 percent, whereas more recent single-dose coverage among English year-10 students has slipped to 75.5 percent for girls and 70.5 percent for boys in the 2024 to 2025 academic year. Sustained declines in uptake could erode both direct protection and herd effects in future cohorts. Equity is equally central: coverage must be monitored by geography, deprivation, school attendance, and migration status, because lower uptake in specific subgroups can preserve pockets of preventable disease even when national averages look favorable. On safety, common adverse effects such as injection-site pain, dizziness, nausea, and headache are generally mild, and WHO safety reviews have not supported a causal association between HPV vaccination and infertility.

The global implications are framed through the World Health Organization’s 90-70-90 elimination strategy, which targets 90 percent of girls fully vaccinated by age 15, 70 percent of women screened with a high-performance test at ages 35 and 45, and 90 percent of women with precancer or invasive cancer appropriately treated. Yet the review’s regional analysis shows how unevenly these tools are distributed. In the WHO Eastern Mediterranean Region, an estimated 16,833 new cervical cancer cases and 10,704 deaths occurred in 2022, and a 2026 regional review found that only eight of 22 countries had national HPV vaccination programmes while only seven reported cervical screening programmes, all opportunistic and cytology-based. Qatar illustrates the implementation gap: GLOBOCAN 2024 estimated 37 new cases and 13 deaths there, HPV vaccination was approved only in May 2023 as an optional offering, and no robust national coverage estimate exists. Among 398 university students surveyed in Doha, just 6.3 percent reported prior vaccination, though 71 percent of unvaccinated students said they would accept the vaccine if a healthcare professional recommended it, and a survey of 557 Qatari physicians identified limited public awareness and reluctance to discuss sexual health as key barriers.

The durable message of the review is broader than any single zero-death observation. Vaccinate early, maintain high and equitable coverage, continue appropriate cervical screening, treat precancer and cancer promptly, and monitor outcomes by age, geography, and socioeconomic indicators over decades. The strongest current mortality evidence comes from young cohorts in whom absolute deaths are rare and expected deaths are modeled from historical trends, and the effect on mortality after age 40, when cervical cancer deaths become more common, remains unknown and will require long follow-up. England’s ambition to eliminate cervical cancer by 2040 shows how vaccination, screening, and treatment can be organized toward a common endpoint, but the English mortality estimates should be understood as evidence of achievable population benefit under high-coverage conditions, not as a numerical forecast that any country can simply import. HPV vaccination has now progressed convincingly from preventing infection, to preventing cancer, to preventing death at the population level, and the task ahead is to make that progression possible everywhere.

Subject of Research: Population-level evidence linking prophylactic HPV vaccination to the prevention of cervical cancer mortality

Article Title: HPV vaccination and cervical cancer deaths: from incidence reduction to mortality prevention

Article References: Alkhanafsa, M., Wafi, J., Deek, S., & Abdalhadi, A. (2026). HPV vaccination and cervical cancer deaths: from incidence reduction to mortality prevention. Clinical Cancer Bulletin, 5(1), Article 22. https://doi.org/10.1007/s44272-026-00074-2

Image Credits: AI Generated

DOI: 10.1007/s44272-026-00074-2

Keywords: HPV vaccination, cervical cancer, cervical cancer mortality, HPV16, HPV18, cervical screening, CIN3, WHO 90-70-90 targets, cancer elimination, England HPV programme, Eastern Mediterranean Region, vaccine coverage

The biological rationale behind the study rests on the well-established role of HPV16 in cervical carcinogenesis. Persistent infection with high-risk HPV types is the major cause of cervical cancer worldwide, and the viral oncoproteins E6 and E7 are the principal effectors of that transformation. E6 promotes the ubiquitin-mediated degradation of the p53 tumor suppressor, disabling a cell’s primary safeguard against DNA damage and uncontrolled proliferation, while E7 disrupts the retinoblastoma protein pathway. Beyond these canonical functions, the viral oncoproteins also reshape the landscape of microRNA expression in infected cells. MicroRNAs are short, non-coding RNA molecules that regulate gene expression after transcription by binding target messenger RNAs and suppressing their translation or promoting their degradation. Because a single microRNA can influence dozens of targets, shifts in microRNA profiles can ripple across entire signaling networks, and viral manipulation of these regulators is increasingly recognized as a hallmark of HPV-associated cancers.

To test whether chrysin could counteract these effects, the team treated CaSki cells, a cervical cancer cell line that carries integrated HPV16 DNA, alongside normal human dermal fibroblasts as a non-cancerous comparison. The cells were exposed to chrysin across a concentration range of 31.5 to 500 micrograms per milliliter for two exposure periods of 24 and 48 hours. Cell viability was measured using the MTT assay, a colorimetric method in which metabolically active cells convert a yellow tetrazolium salt into a purple formazan product, allowing the proportion of surviving cells to be quantified. The researchers then quantified the expression of five selected microRNAs, miR-34a, miR-218, miR-20a, miR-195, and miR-23b, by quantitative reverse transcription polymerase chain reaction, calculating relative expression with the 2 to the power of negative delta delta Ct method. Levels of the HPV16 E6 protein were assessed by Western blotting, which separates proteins by molecular weight and detects the target with specific antibodies.

The viability results were striking for their selectivity. Chrysin reduced the survival of CaSki cells in a dose- and time-dependent manner, but it showed minimal toxicity toward the normal dermal fibroblasts at the same concentrations, yielding a high selectivity index. This therapeutic window matters because many candidate anticancer compounds fail precisely at this hurdle, killing tumor cells and healthy tissue alike. A high selectivity index suggests that the compound’s cytotoxic mechanisms preferentially target vulnerabilities present in the cancer cells, such as the altered survival signaling and metabolic rewiring characteristic of HPV-transformed lines, rather than general cellular processes shared by all dividing cells.

The microRNA findings provided the study’s most detailed molecular picture. After chrysin treatment, miR-34a expression rose approximately 10.05-fold compared with untreated controls, a change that reached a statistical significance level of P less than 0.0001. miR-218 increased 5.64-fold with P less than 0.01, and miR-20a showed a more moderate 1.7-fold increase with P less than 0.05. In contrast, miR-195 expression fell to 0.18-fold of control levels with P less than 0.01, while miR-23b showed no statistically significant change. Each of these microRNAs has documented connections to cancer biology. miR-34a is a transcriptional target of p53 and one of the best-characterized tumor-suppressive microRNAs, and previous work has shown that the HPV E6 oncoprotein interrupts its expression, effectively severing a p53-dependent regulatory arm. The restoration of miR-34a after chrysin treatment is therefore consistent with the concurrent reduction in E6 protein that the team observed.

miR-218, the second most strongly induced microRNA in the study, functions as a tumor suppressor in cervical cancer, where it has been shown to inhibit epithelial-to-mesenchymal transition, migration, and invasion by targeting genes such as SFMBT1 and DCUN1D1 and by acting within the SLIT/ROBO signaling pathway. Its fivefold increase after chrysin exposure suggests that the flavonoid may reinforce anti-metastatic regulatory circuits in addition to affecting viral oncoprotein abundance. The moderate rise in miR-20a is more nuanced, because members of the miR-17-92 cluster to which it belongs can behave as oncomiRs in some contexts while showing context-dependent effects in others. The decrease in miR-195, which has been reported to play roles in gynecological cancers with both tumor-suppressive and proliferative implications depending on setting, likewise underscores that microRNA responses to phytochemicals are not uniformly one-directional and require interpretation against specific cellular backgrounds.

Perhaps the most consequential measurement was the Western blot result for the viral oncoprotein itself. Chrysin-treated CaSki cells showed a significant reduction in HPV16 E6 protein levels, with treated samples measuring 0.64 relative to untreated controls, a difference significant at P less than 0.001. Because E6 is the viral factor responsible for targeting p53 for degradation, lowering E6 abundance could, in principle, allow p53-dependent tumor-suppressive programs to partially recover. The observed tenfold induction of miR-34a, a canonical p53-responsive microRNA, fits this interpretation, although the study’s design establishes association rather than a fully mapped causal chain. The authors are careful to frame the findings accordingly, noting that the concurrent modulation of E6 and several cancer-related microRNAs indicates a link but that the underlying pathways remain to be clarified.

The study also situates itself within a broader research effort on chrysin, a flavone with the chemical name 5,7-dihydroxyflavone. Prior investigations have documented apoptotic effects of chrysin in various human cancer cell lines, selective antiproliferative and antimigratory activity across a panel of cervical cancer-derived lines, inhibition of HeLa cell propagation through attenuation of cell survival signaling, and induction of both intrinsic and extrinsic apoptosis in ovarian cancer cells delivered via chrysin-loaded micelles. Chrysin has also been reported to alter microRNA expression in gastric cancer cells, suggesting that modulation of post-transcriptional regulation may be a recurring feature of its anticancer activity. At the same time, the compound faces a familiar obstacle for polyphenolic phytochemicals: poor aqueous solubility and limited bioavailability, which have motivated formulation strategies such as nanoparticle and micellar delivery systems in recent preclinical work.

For the cervical cancer field specifically, the results contribute to an emerging interest in natural products as sources of multi-target agents against HPV-driven disease. Because E6 and E7 are usually maintained in cervical tumors even as other viral genes are lost, they represent attractive therapeutic targets, and compounds that reduce E6 protein levels could complement existing prevention and treatment strategies, from vaccination and screening to surgery, radiotherapy, and chemotherapy. The microRNA dimension adds a further layer of potential value, since circulating miR-34a, miR-218, and related species have been proposed as early, minimally invasive biomarkers of cervical carcinogenesis, and microRNA profiles could in principle serve as pharmacodynamic readouts of a compound’s activity.

The authors and outside observers alike emphasize the preliminary nature of the work. All experiments were conducted in a single HPV16-positive cell line with one normal comparator, over exposure windows of 24 and 48 hours, and the study did not generate or analyze external datasets. Whether the E6 reduction results from effects on viral gene transcription, on E6 messenger RNA stability, on protein translation, or on protein degradation pathways, and whether the microRNA changes drive the cytotoxicity or merely accompany it, are questions the current design cannot answer. The researchers state that further studies in additional cellular models and mechanistic systems are required to clarify the underlying pathways. Translational development would also need to confront chrysin’s bioavailability limitations and establish efficacy and safety in animal models before any clinical relevance could be assessed. For now, the study offers a carefully documented snapshot of a common dietary flavonoid simultaneously touching a viral oncoprotein and a network of cancer-related microRNAs in cervical cancer cells, a combination that justifies closer mechanistic scrutiny.

Subject of Research: Effects of the flavonoid chrysin on HPV16 E6 oncoprotein levels and cancer-related microRNA expression in cervical cancer cells

Article Title: Chrysin treatment is associated with altered microrna expression and reduced levels of HPV16 E6 protein in caski cervical cancer cells

Article References: Gholami Fashkhami, M., Habibollahi, H., & Shafighi, S. T. (2026). Chrysin treatment is associated with altered microrna expression and reduced levels of HPV16 E6 protein in caski cervical cancer cells. Medical Oncology, 43(10), Article 257. https://doi.org/10.1007/s12032-026-03381-9

Image Credits: AI Generated

DOI: 10.1007/s12032-026-03381-9

Keywords: chrysin, cervical cancer, HPV16, E6 oncoprotein, microRNA, CaSki cells, flavonoid, miR-34a, miR-218, phytochemical, cell viability, Medical Oncology

Human papillomavirus is the most common sexually transmitted infection worldwide and the necessary cause of nearly all cervical cancer cases. Yet the virus is far from uniform: its genotype distribution varies markedly between countries, regions, and even cities, and those differences matter enormously for vaccination policy. Prophylactic HPV vaccines target specific subsets of genotypes, so knowing which types actually prevail in a given population determines how much protection a vaccination program can realistically deliver. Because large-scale data on genotype prevalence and viral load characteristics in the Taihu region had been lacking, the research team set out to fill that gap with a three-year survey spanning January 2023 to December 2025.

The study design was straightforward but ambitious. The investigators analyzed cervical exfoliated cell samples collected from 23,196 women who underwent HPV testing at their institution during the study window. Each sample was screened for 21 HPV genotypes using real-time fluorescence quantitative polymerase chain reaction, a technique that both identifies the viral type present and quantifies how much viral DNA is in the specimen. This dual capability allowed the team to go beyond simple positivity rates and construct viral load profiles across age groups, a dimension that many prevalence surveys omit.

The headline finding was an overall HPV infection rate of 13.20 percent, with 3,061 of the 23,196 participants testing positive. Notably, this rate remained statistically stable across the three years of the study, suggesting an entrenched and steady level of viral circulation in the region rather than a rising or falling epidemic curve. That stability provides a useful baseline against which the future impact of vaccination and screening programs can be measured.

Perhaps the most striking pattern emerged when the researchers stratified infections by age. Rather than declining monotonically with age, as some classical models of HPV epidemiology predict, prevalence followed a bimodal distribution. The highest infection rate appeared in women aged 60 and older, while the lowest rate occurred among women aged 40 to 49. This shape echoes findings from other Chinese regions and reflects a complex interplay of factors: cohort effects in lifetime exposure, changes in immune competence with age, hormonal shifts after menopause, and possibly reduced participation in screening among older women, allowing persistent infections to accumulate undetected.

The genotype ranking carried direct implications for vaccine policy. Among high-risk types, HPV52 led with a prevalence of 2.70 percent, followed by HPV58 at 1.72 percent, HPV16 at 1.35 percent, HPV39 at 1.11 percent, and HPV56 at 0.96 percent. Among low-risk genotypes, HPV53 was the most common, detected at 1.78 percent. HPV16, the single most carcinogenic type globally, ranked only third locally, while HPV52 and HPV58, types that are notably overrepresented in Asian populations relative to Western ones, dominated. This regional signature matters because the bivalent and quadrivalent vaccines, which target HPV16 and HPV18 (with the quadrivalent also covering HPV6 and HPV11), would leave a substantial fraction of local infections uncovered. The nonavalent vaccine, which adds HPV31, HPV33, HPV45, HPV52, and HPV58 to the mix, aligns far better with the genotype spectrum observed in Taihu, and the authors concluded that their data show greater theoretical concordance with the nine-valent formulation.

Age also shaped the composition of infections in ways that compound the vulnerability of older women. Women aged 60 and above exhibited significantly higher proportions of high-risk mixed infections and multiple-genotype infections compared with all other age groups. Multiple infections, in which two or more HPV types coexist in the same cervical sample, are of particular clinical interest because co-infection can complicate risk stratification and may reflect broader exposure or diminished viral clearance. The elevated burden of mixed high-risk infections in older women underscores that HPV is not simply a concern of young adulthood and that screening programs must not neglect postmenopausal populations.

The viral load analysis added a further layer of nuance. Viral load, typically measured as the quantity of viral DNA per cellular sample, is thought to correlate with infection persistence and lesion risk, although its clinical interpretation remains debated. In this cohort, the distribution of viral loads varied systematically with age. High viral loads were most frequent among women under 30, accounting for 24.29 percent of infections in that group, whereas low viral loads predominated among women aged 60 and older, making up 46.82 percent of their infections. One plausible interpretation is that younger women carry more recently acquired, actively replicating infections that are often cleared by the immune system, while older women more frequently harbor long-standing, low-level persistent infections whose cumulative cellular damage may be clinically significant despite modest viral quantities.

Taken together, the results sketch a coherent picture of HPV epidemiology in the Taihu region: a stable overall prevalence near 13 percent, a genotype hierarchy led by HPV52, HPV58, and HPV16, a bimodal age distribution peaking in the oldest women, and an age-dependent viral load architecture. The authors argue that these findings argue for region-specific prevention and control strategies rather than one-size-fits-all policies. In practical terms, that means prioritizing vaccines whose genotype coverage matches local circulating types, sustaining and possibly extending cervical screening into older age brackets, and considering viral load and multiple-infection status when triaging positive results in clinical practice.

The study also demonstrates the value of quantitative PCR-based surveillance as a public health instrument. By combining genotyping with viral load quantification across a very large sample, the Taihu dataset offers a template for other regions in China and beyond that lack local HPV epidemiology. As vaccination programs scale up globally, longitudinal studies of this kind will be essential for tracking shifts in genotype prevalence, detecting vaccine-type declines, and identifying any replacement by non-vaccine types. For now, the message from Suzhou is clear: the local viral landscape favors the broadest available vaccine coverage, and older women deserve renewed attention in the campaign against cervical cancer.

Subject of Research: Epidemiology, genotype distribution, and viral load profiles of human papillomavirus infection among women in the Taihu region of Suzhou, China

Article Title: Epidemiological characteristics, genotype distribution, and viral load profiles of human papillomavirus infection among women in the Taihu region of Suzhou: a retrospective study

Article References: Guo, J., Yan, R., & Qu, Y. (2026). Epidemiological characteristics, genotype distribution, and viral load profiles of human papillomavirus infection among women in the Taihu region of Suzhou: a retrospective study. Virology Journal. https://doi.org/10.1186/s12985-026-03301-3

Image Credits: AI Generated

DOI: 10.1186/s12985-026-03301-3

Keywords: human papillomavirus, HPV prevalence, HPV52, HPV58, HPV16, genotype distribution, viral load, cervical cancer, nonavalent vaccine, Suzhou, retrospective study, qPCR

The study, published as an open-access research article in Virology Journal, is notable for combining HPV DNA testing with concurrent cervical cytology in a single, large cohort. Women undergoing routine health examinations at participating facilities provided cervical samples for HPV genotyping and ThinPrep cytologic testing. The cohort had a median age of 42 years, with an interquartile range of 36 to 51 years, placing most participants squarely within the age band where cervical cancer screening is most actively recommended. By pairing molecular virology with cytological classification, the researchers were able to map how individual viral genotypes distribute themselves across the spectrum of cervical abnormalities, from benign findings to high-grade lesions.

HPV is a double-stranded DNA virus with more than 200 known genotypes, of which roughly a dozen, designated high-risk types, are established causes of cervical cancer. Persistent infection with HPV16 and HPV18 accounts for the majority of cervical cancer cases worldwide, which is why these two genotypes anchor the bivalent and quadrivalent vaccines, while the nonavalent formulation extends coverage to HPV31, 33, 45, 52 and 58. The Shanxi data confirm that the regional genotype landscape does not perfectly mirror the global one. HPV52 was the single most prevalent high-risk genotype at 2.3 percent, ahead of HPV16 and HPV58, each at 1.7 percent. Combined prevalence of HPV16 and HPV18 was 2.3 percent, while the nine genotypes covered by the nonavalent vaccine collectively accounted for 7.4 percent of infections, meaning roughly two-thirds of high-risk infections in this population fall within the nonavalent vaccine’s protective umbrella.

Beyond genotype frequencies, the researchers used multivariable logistic regression to isolate risk factors associated with high-risk HPV infection. Age emerged as a strong and independent determinant. Compared with women aged 20 to 35 years, those aged 56 to 65 years had roughly twice the odds of carrying a high-risk infection, with an adjusted odds ratio of 2.0 and a 95 percent confidence interval of 1.6 to 2.3. This pattern is consistent with a recognized second peak of HPV prevalence among older women, often attributed to reactivation of previously acquired latent infections, declining immune surveillance after menopause, or cohort effects related to sexual behavior and screening history in older generations. Marital status also carried a signal: married women had about half the odds of high-risk HPV infection compared with unmarried women, an adjusted odds ratio of 0.5 with a confidence interval of 0.4 to 0.7, a finding the authors report without overinterpreting its behavioral or social underpinnings.

Cytological abnormalities were far less common than viral infections overall. Abnormal cytology was detected in 2.1 percent of the 19,384 participants, spanning the full range of the Bethesda classification system, from atypical squamous cells of undetermined significance through low-grade and high-grade squamous intraepithelial lesions. The relatively low rate of abnormal cytology reflects the natural history of HPV disease: most infections are transient and cleared by cell-mediated immunity within one to two years, and only a small fraction of persistent infections progress through cytological change toward malignancy. This biological bottleneck is precisely what makes genotype-specific surveillance valuable, because identifying which viral types are enriched among abnormal cytology results sharpens the predictive value of screening.

The most striking analytical finding concerns how genotype composition shifts with lesion severity. Among HPV-positive women, the prevalence of HPV16 and HPV18 rose significantly as cytological grade increased, with a 3.4-fold higher odds of these two genotypes in atypical squamous cells cannot exclude high-grade lesion or high-grade squamous intraepithelial lesion categories compared with low-grade lesions, at an odds ratio of 3.4 and a confidence interval of 1.0 to 11.5. The genotypes HPV31, 33, 45, 52 and 58 showed a moderate but statistically non-significant increase across severity strata, with an odds ratio of 1.8 and a confidence interval spanning 0.6 to 5.6. Meanwhile, high-risk genotypes outside this seven-type group actually declined in prevalence as lesions became more severe, with an odds ratio of 0.6 and a confidence interval of 0.1 to 2.2. In other words, the viral population underlying mild abnormalities is more heterogeneous, whereas severe lesions concentrate around the genotypes with established oncogenic potency.

From a virological standpoint, this gradient makes mechanistic sense. HPV16, and to a lesser extent HPV18, carry sequence variations in the E6 and E7 oncogenes and in regulatory regions that favor expression of proteins which degrade the p53 and retinoblastoma tumor suppressor pathways. Viruses equipped with these features are more likely to escape cell-cycle control long enough for a lesion to progress, which is why they dominate the high-grade end of the spectrum even when other genotypes are more common among transient infections. HPV52 and HPV58, both classified as high-risk and both notably prevalent in East Asian populations, appear to occupy an intermediate position, contributing substantially to infection burden and to lesions, but with a weaker per-infection association with severe cytology than HPV16/18 in this dataset.

The timing of these findings amplifies their policy relevance. China’s decision to introduce HPV vaccination into its national immunization programme in November 2025 created an urgent need for baseline genotype distribution data across representative provinces. Without such baselines, it would be difficult to distinguish vaccine-driven changes in genotype prevalence from natural fluctuations. The Shanxi results suggest that bivalent and quadrivalent vaccination, which target HPV16 and HPV18 plus HPV6 and 11 in the quadrivalent formulation, will directly address only about one-fifth of the high-risk infections observed here, while nonavalent vaccination would cover roughly two-thirds. At the same time, the significant enrichment of HPV16/18 among high-grade lesions means those two genotypes still account for a disproportionate share of the abnormalities most likely to progress toward cancer, so even narrower vaccines should deliver outsized reductions in cancer incidence.

The authors emphasize that their data support genotype-specific risk assessment as a pillar of future cervical cancer prevention in China. As vaccination scales up, screening programmes may need to adapt, potentially shifting toward HPV-based primary screening with genotyping for HPV16 and HPV18, followed by reflex cytology, a triage algorithm already adopted in many high-income settings. The observed age-related rise in prevalence also cautions against focusing vaccination and screening exclusively on younger cohorts; older women, who are largely beyond catch-up vaccination eligibility, will continue to carry a substantial burden of infection for decades and will remain dependent on effective cytological or molecular screening. The finding that married women had lower infection odds, whatever its underlying behavioral explanation, may help target health education and screening outreach toward demographic groups with higher observed risk.

As with all cross-sectional designs, the study captures a single snapshot in time and cannot establish whether infections preceded cytological changes, nor can it follow individuals to confirm clearance or progression. The participant pool, drawn from women presenting for routine health examinations, may also skew toward populations with better healthcare access than the general provincial population. Nevertheless, with nearly twenty thousand paired HPV and cytology results, the study offers an unusually granular portrait of HPV epidemiology in a region of China where such data had been limited. As the national vaccination programme matures, repeated iterations of this kind of surveillance in Shanxi and comparable provinces will be essential for verifying whether the vaccine is bending the genotype distribution curve, reducing cytological abnormalities, and ultimately accelerating China’s progress toward the World Health Organization’s cervical cancer elimination targets.

Subject of Research: Prevalence, genotype distribution and risk factors of human papillomavirus infection and cervical cytological abnormalities among women in Shanxi, China

Article Title: Prevalence and risk factors of human papillomavirus infection and cervical cytological lesions among women in Shanxi, China: a cross-sectional study

Article References: Ge, S., Gao, H., Wang, J., Guo, S., Chang, Y., Qi, Y., Han, J., Jia, Y., Dong, J., & Wei, F. (2026). Prevalence and risk factors of human papillomavirus infection and cervical cytological lesions among women in Shanxi, China: a cross-sectional study. Virology Journal. https://doi.org/10.1186/s12985-026-03300-4

Image Credits: AI Generated

DOI: 10.1186/s12985-026-03300-4

Keywords: human papillomavirus, HPV prevalence, HPV52, HPV16, HPV58, cervical cytology, cervical cancer, genotype distribution, high-risk HPV, cross-sectional study, Shanxi China, HPV vaccination