Hepatocellular carcinoma remains one of the deadliest malignancies worldwide, ranking among the leading causes of cancer-related death. Its lethality stems largely from two clinical realities: a strong tendency to spread beyond the liver, and a stubborn resistance to conventional chemotherapeutic agents. Even as immunotherapy and targeted agents reshape the treatment landscape, many patients progress rapidly, and the molecular drivers of that progression have remained only partially mapped. The new findings add a critical piece to that map, positioning ApoA2 not as a passive biomarker but as an active participant in the tumor’s malignant behavior.

Apolipoproteins are best known for their role in lipid metabolism, shuttling cholesterol and triglycerides through the circulation. ApoA2 is a major constituent of HDL particles, and circulating levels of the protein have previously been associated with metabolic syndrome, cardiovascular disease, and, intriguingly, with altered risk profiles in several cancers. Epidemiological observations had hinted at connections between ApoA2 abundance and tumor behavior, but the mechanistic basis for such a link was unclear. The new study set out to determine whether ApoA2 is merely a correlate of disease severity or a genuine contributor to it.

Using hepatocellular carcinoma cell lines, animal models, and clinical tissue samples, the researchers found that ApoA2 expression is elevated in aggressive tumors and correlates with poor prognosis. When the team manipulated ApoA2 levels in laboratory models, the consequences were striking. Increasing ApoA2 enhanced the migratory and invasive capacity of cancer cells, while suppressing it markedly reduced metastatic potential. In mouse models of liver cancer, tumors with high ApoA2 activity spread more readily and responded poorly to chemotherapy, whereas lowering ApoA2 restored drug sensitivity and curtailed tumor dissemination.

The mechanistic heart of the paper lies in the HMGB1/IL-17A axis. HMGB1, or high-mobility group box 1, is a DNA-binding protein that normally resides in the nucleus, where it helps regulate gene expression and genome architecture. When cells are stressed, damaged, or activated by inflammatory signals, HMGB1 can be released into the extracellular space, where it acts as a danger signal, or alarmin, binding to receptors such as RAGE and Toll-like receptors to ignite inflammatory responses. The study demonstrates that ApoA2 promotes the secretion of HMGB1 from hepatocellular carcinoma cells, converting an intracellular housekeeping protein into an extracellular inflammatory messenger.

Once outside the cell, HMGB1 sets off a chain reaction. The researchers show that extracellular HMGB1 stimulates the production of interleukin-17A, a pro-inflammatory cytokine classically associated with Th17 immune cells but increasingly recognized as a product of the tumor microenvironment itself. IL-17A is known to fuel chronic inflammation, promote angiogenesis, and foster an immunosuppressive milieu that favors tumor growth. In this context, the ApoA2-HMGB1-IL-17A circuit appears to create a self-reinforcing inflammatory loop within and around the tumor, one that simultaneously drives cells toward invasive behavior and shields them from the cytotoxic effects of chemotherapeutic drugs.

The drug resistance component of the findings is particularly consequential. Chemotherapy for hepatocellular carcinoma has long been hampered by modest response rates, and understanding why some tumors shrug off treatment is a central question in the field. The study provides evidence that the HMGB1/IL-17A pathway activated by ApoA2 helps cancer cells survive drug-induced stress, likely through inflammatory survival signaling and alterations in the tumor microenvironment that blunt drug efficacy. When the researchers interfered with the axis, blocking HMGB1 or neutralizing IL-17A, the resistance phenotype weakened, suggesting that each node in the pathway represents a potential therapeutic target.

From a translational standpoint, the work carries several implications. First, ApoA2 could serve as a biomarker to identify patients whose tumors are predisposed to metastasis and treatment failure, allowing clinicians to stratify therapy more aggressively from the outset. Second, existing drugs or biologics that target IL-17A, some of which are already approved for inflammatory diseases such as psoriasis, could potentially be repurposed or adapted for hepatocellular carcinoma, either alone or in combination with chemotherapy or immunotherapy. Third, the identification of HMGB1 as a pivotal intermediary offers another intervention point, and HMGB1 inhibitors are an area of active pharmaceutical development.

The findings also resonate with a broader conceptual shift in cancer biology: the recognition that metabolic proteins and inflammatory circuits are deeply intertwined with malignant progression. Tumors do not evolve in isolation; they co-opt the body’s lipid transport machinery, danger-sensing systems, and immune signaling networks to advance their own agenda. The ApoA2/HMGB1/IL-17A axis is a vivid example of this co-option, linking a routine component of blood lipid particles to the inflammatory engine that powers metastasis and treatment resistance. It underscores why chronic inflammation of the liver, whether from viral hepatitis, alcohol, or fatty liver disease, creates such fertile ground for cancer, and why interrupting inflammatory signaling may be as important as attacking the cancer cells directly.

As with any preclinical study, important questions remain before the findings can change clinical practice. The precise molecular steps by which ApoA2 triggers HMGB1 release, the relative contributions of tumor cells versus immune cells to IL-17A production, and the safety of targeting this axis in patients with underlying liver disease all require further investigation. Human validation in large, prospective cohorts will be essential to confirm ApoA2’s prognostic value. Nevertheless, the study delivers a compelling and mechanistically grounded case that a familiar blood protein is an unexpected architect of liver cancer aggression, and it opens a concrete path toward therapies that could strip hepatocellular carcinoma of two of its most dangerous weapons: the ability to spread and the ability to survive treatment.

Subject of Research: The role of apolipoprotein A2 in promoting metastasis and drug resistance in hepatocellular carcinoma through the HMGB1/IL-17A inflammatory signaling axis.

Article Title: ApoA2 promotes tumor metastasis and drug resistance in hepatocellular carcinoma by activating the HMGB1/IL-17A axis

Article References: Fu, Z., Zhu, F., Fu, Z., Wang, C., Guan, T., Yuan, Y., Zhang, S., & Zhang, T. (2026). ApoA2 promotes tumor metastasis and drug resistance in hepatocellular carcinoma by activating the HMGB1/IL-17A axis. Cell Death Discovery. https://doi.org/10.1038/s41420-026-03317-2

Image Credits: AI Generated

DOI: 10.1038/s41420-026-03317-2

Keywords: ApoA2, hepatocellular carcinoma, HMGB1, interleukin-17A, metastasis, drug resistance, liver cancer, inflammation, tumor microenvironment, biomarker, cytokine signaling, chemotherapy

Insulin resistance is a central feature of metabolic syndrome and a powerful driver of type 2 diabetes and cardiovascular disease. In the modern antiretroviral therapy era, people living with HIV increasingly face a heightened burden of metabolic disorders, often at younger ages than the general population. While the shift to integrase strand transfer inhibitor-based regimens has dramatically improved viral suppression and drug tolerability, these regimens have also been linked to disproportionate weight gain and metabolic dysfunction, particularly among women. Understanding how sex, HIV, and related biological pathways interact to influence insulin resistance is therefore a pressing question for populations shouldering a dual burden of infectious and non-communicable diseases.

The research team recruited participants from the medical outpatient clinic between August 2023 and April 2024. People living with HIV had to have been on antiretroviral therapy for at least six months and achieved viral suppression, defined as a viral load below 50 copies per milliliter. Participants with conditions that could distort metabolic or inflammatory measurements, such as pregnancy, active malignancy, acute infections, or severe renal or hepatic disease, were excluded. After an overnight fast of eight to twelve hours, blood samples were collected and processed within two hours, with plasma and serum aliquots stored at minus 80 degrees Celsius until analysis.

In the laboratory, fasting glucose and lipid profiles were measured with automated clinical chemistry analyzers, while fasting insulin was quantified by immunoassay. HOMA-IR was calculated from fasting insulin and glucose values, with participants classified as insulin resistant at a threshold of 1.9 or above. The team also measured high-sensitivity C-reactive protein and interleukin-17A, a pro-inflammatory cytokine linked to Th17 immune responses, as well as angiotensin II, the primary effector peptide of the renin-angiotensin system, which has been implicated in promoting insulin resistance by interfering with insulin signaling and inducing oxidative stress in skeletal muscle and adipose tissue. All enzyme-linked immunosorbent assays were performed in duplicate with intra-assay coefficients of variation below 8 percent.

The cohort comprised 79 men and 154 women, with comparable median ages of roughly 48 years. Women carried a less favorable adiposity profile, with a higher mean body mass index of 26.9 versus 23.5 kilograms per square meter and larger waist circumferences of 88.3 versus 83.2 centimeters, indicating greater central obesity. Women also showed higher fasting insulin levels and higher HOMA-IR scores, together with a higher prevalence of insulin resistance at 17.5 percent compared with 12.7 percent in men. Inflammatory markers trended higher among women, although the variability was substantial, while men exhibited markedly higher alanine aminotransferase levels, hinting at sex-specific hepatic or metabolic stress.

The adjusted regression analysis for the overall population delivered two striking results. Female sex was independently associated with higher HOMA-IR, with a beta coefficient of 0.95 and a p-value of 0.037, while HIV-positive status was independently associated with lower HOMA-IR, with a beta of minus 1.54 and a p-value of 0.046. Hypertension, triglycerides, estimated glomerular filtration rate, angiotensin II, and interleukin-17A were not independently associated with insulin resistance in the combined model. The inverse HIV association was particularly pronounced among women, where HIV-positive status remained significantly linked to lower HOMA-IR after adjustment, with a beta of minus 2.31 and a p-value of 0.049.

Sex-stratified analyses revealed further divergence. Among men, hypertension was independently associated with higher HOMA-IR, with a beta of 0.61 and a p-value of 0.019, while higher estimated glomerular filtration rate was linked to lower insulin resistance, with a beta of minus 0.01 and a p-value of 0.029. This supports the well-established bidirectional relationship between hypertension and insulin resistance, in which insulin resistance promotes endothelial dysfunction, sympathetic nervous system activity, and oxidative stress, all of which can elevate blood pressure. The kidney finding suggests that impaired renal function, increasingly recognized as both a consequence and a contributor to insulin resistance through chronic inflammation, oxidative stress, and altered insulin clearance, may be an important metabolic correlate in men but not in women.

The authors caution that several findings warrant careful interpretation. Neither angiotensin II nor interleukin-17A was independently associated with HOMA-IR, a result that contrasts with experimental evidence implicating renin-angiotensin system activation and inflammatory pathways in insulin resistance. The researchers note that circulating biomarker concentrations may not fully capture tissue-level activity, and the cross-sectional design precludes any inference about temporal relationships. They also emphasize that the apparent sex differences were not formally tested for interaction, so statistical significance in one sex but not the other does not confirm true effect modification. The relatively small male subgroup of 79 participants may have reduced statistical power and produced less stable regression estimates.

The relatively low mean HOMA-IR values observed in this Zambian cohort also merit attention. Similar findings have been reported in other sub-Saharan African populations and may reflect differences in body composition, dietary patterns, physical activity, and genetic background compared with Western populations, where HOMA-IR thresholds of 2.5 to 3.0 are commonly applied. The authors suggest that thresholds derived from European and North American populations may not be directly applicable to African populations, underscoring the need for population-specific reference values in metabolic risk assessment.

Despite these limitations, the study offers a valuable exploratory framework for understanding sex-specific metabolic risk in African populations affected by HIV. The absence of data on physical activity, dietary intake, and menopausal status, particularly important given the median female age of 48 years, leaves open the question of whether the observed patterns reflect biological sex differences, lifestyle factors, hormonal status, or their interactions. The authors call for larger, adequately powered studies integrating comprehensive lifestyle, hormonal, inflammatory, and treatment-related assessments. In the meantime, the findings argue for incorporating sex-specific considerations into the assessment and management of insulin resistance, particularly in populations living with HIV, where metabolic risk pathways may diverge sharply between men and women.

Subject of Research: Sex differences in insulin resistance and associated metabolic and inflammatory markers among adults with and without HIV in Zambia

Article Title: Sex differences in insulin resistance and associated metabolic and inflammatory markers among adults with and without HIV in Zambia

Article References: Sibbenga, F., Chisompola, D., Chipuma, M., Chakulya, M., Lwiindi, P., Liamba, M. A., Hamooya, B. M., Povia, J. P., Liweleya, S., & Masenga, S. K. (2026). Sex differences in insulin resistance and associated metabolic and inflammatory markers among adults with and without HIV in Zambia. Physiological Reports, 14(17), Article e71093. https://doi.org/10.14814/phy2.71093

Image Credits: AI Generated

DOI: 10.14814/phy2.71093

Keywords: insulin resistance, HOMA-IR, HIV, Zambia, sex differences, hypertension, kidney function, angiotensin II, interleukin-17A, antiretroviral therapy, metabolic syndrome, inflammation