Two Circulating MicroRNAs Track Inflammation and Cachexia in Oesophageal Cancer

The two candidates, hsa-miR-5187-5p and hsa-miR-4433b-3p, were identified by plasma small-RNA sequencing and confirmed across an entire patient cohort, and their levels tracked inflammatory cytokines, nutritional blood markers and, in unadjusted analyses, shorter survival. The authors are careful to frame the work as exploratory: every measurement came from a single centre, and no independent cohort was available to test whether the signature holds up.

The study enrolled 126 participants at Nantong First People’s Hospital in China: 42 healthy volunteers and 84 patients with histopathologically confirmed oesophageal squamous cell carcinoma, a tumour type that accounts for roughly 90 percent of oesophageal cancers and carries a five-year survival rate of about 20 percent. Newly diagnosed patients were recruited consecutively between January and December 2021 and had received no prior antitumour treatment. Using international consensus criteria, the patient group was split evenly into 42 cachectic and 42 non-cachectic individuals. Cachexia, the multifactorial syndrome of progressive skeletal muscle loss that conventional nutritional support cannot fully reverse, matters clinically because it is associated with poorer treatment tolerance, more postoperative complications, reduced quality of life and shorter survival.

The discovery phase was deliberately small. Plasma small-RNA sequencing was performed in just 12 participants, four per group, with differentially expressed microRNAs defined as those showing a p value below 0.05 and an absolute log2 fold change greater than 2. Intersection analysis of microRNAs upregulated in cachectic patients compared with both healthy controls and non-cachectic patients pointed to exactly two candidates. The researchers then measured both across the full cohort using quantitative reverse-transcription PCR, normalised against the U6 small nuclear RNA, and found a stepwise increase from healthy controls to non-cachectic patients to cachectic patients, with the highest expression in the cachectic group.

How well did the two molecules separate the groups? In within-cohort receiver operating characteristic analysis, hsa-miR-5187-5p distinguished healthy controls from non-cachectic patients with an area under the curve of 0.8435, rising to 0.9439 for healthy controls versus cachectic patients and 0.8594 for non-cachectic versus cachectic patients. Its counterpart performed more modestly between controls and non-cachectic disease, with an area under the curve of 0.6412, but reached 0.8889 against cachectic patients and 0.8175 when cachectic and non-cachectic patients were compared. In other words, both candidates discriminated far more strongly whenever cachectic disease was one of the groups being separated, which is consistent with the microRNAs marking the cachectic phenotype rather than tumour presence alone.

The biochemical backdrop reinforced that interpretation. Cachectic patients had lower albumin, total protein, prealbumin and haemoglobin than non-cachectic patients, and higher concentrations of the inflammatory markers interleukin-6, tumour necrosis factor-alpha, C-reactive protein and interleukin-1 beta, all statistically significant. In cross-sectional correlation analysis, both microRNAs showed weak-to-moderate positive associations with the cytokines and C-reactive protein, and inverse correlations with albumin. The correlation coefficients, ranging roughly from 0.27 to 0.47, indicate partial covariation only, and the authors explicitly caution that they do not demonstrate direct biological regulation or causality.

Survival analyses added a prognostic dimension, though again only in unadjusted form. Cachectic status was associated with shorter overall survival, with a hazard ratio of 1.708. High expression of either microRNA was linked to markedly shorter survival, with hazard ratios of 3.635 for hsa-miR-5187-5p and 3.190 for hsa-miR-4433b-3p, and elevated inflammatory markers were likewise associated with earlier death. Crucially, no multivariable Cox regression was performed because the cohort was considered too small to support stable adjustment, so the analysis cannot determine whether the microRNAs carry prognostic information beyond tumour stage, age or sex. Cachectic patients also had a substantially higher proportion of stage IV disease, meaning tumour burden may partly explain the apparent differences.

Regression modelling told a similar, nuanced story. In univariate logistic regression, neither microRNA distinguished non-cachectic patients from healthy controls, but both were associated with cachectic status in comparisons involving the cachectic group. In exploratory multivariable models that also included the inflammatory markers and albumin, hsa-miR-5187-5p remained associated with cachectic disease, with an odds ratio of 12.885 for cachectic versus non-cachectic patients, whereas hsa-miR-4433b-3p lost statistical significance in the corresponding models. Because tumour stage, age and sex were not included as covariates and some confidence intervals were wide, the authors stress that significance in these models should not be read as independence from tumour burden.

To probe possible biology, the team performed gene ontology and KEGG pathway enrichment on the complete sets of differentially expressed microRNAs. Differences between oesophageal cancer and healthy controls were enriched in signalling-related processes and oncogenic, angiogenic and metabolic pathways, including VEGF, ErbB, p53 and amino-acid metabolism. By contrast, the comparison of cachectic versus non-cachectic patients highlighted lipid metabolism, oxidative stress, cellular senescence, cytokine-cytokine receptor interaction, JAK-STAT, PI3K-Akt, TGF-beta and insulin signalling, a set of pathways well established in muscle wasting biology. Predicted target networks linked both candidate microRNAs to TNF and cytokine signalling, growth-factor pathways and metabolic control, though the authors emphasise that these networks rest on predicted targets and are hypothesis-generating rather than evidence of direct regulation.

The limitations are laid out with unusual candour. The design was cross-sectional, so it cannot establish whether microRNA changes precede clinically evident cachexia. Body composition was estimated from equations based on body mass index, age and sex rather than measured directly, so the indices cannot distinguish skeletal muscle from other lean tissues. The single-centre cohort was modest in size, lacked an external validation set, and the discovery sequencing, cohort-wide PCR and ROC analyses all drew on the same participants, meaning the reported sensitivities, specificities and cut-offs may be optimistic. The use of U6 as a single endogenous reference is acknowledged as a methodological constraint, since circulating microRNA measurements are sensitive to sample processing, haemolysis and normalisation strategy.

What the study ultimately offers is a candidate signature, not a clinical test. The authors position hsa-miR-5187-5p and hsa-miR-4433b-3p as cachexia-associated circulating indicators that mirror an integrated inflammatory, nutritional and metabolic phenotype in oesophageal squamous cell carcinoma, rather than as established diagnostic or prognostic biomarkers. They call for prospective, multicentre, stage-balanced cohorts with separate discovery and validation sets, longitudinal blood sampling, direct assessment of muscle and adipose tissue by imaging, and adequately powered multivariable analyses testing whether the microRNAs add information beyond tumour stage and conventional measures. Functional experiments identifying the cellular origins and molecular targets of the two molecules would also be needed before any claim of mechanism. Until then, the finding stands as an intriguing, carefully caveated signal that the blood of cachectic cancer patients carries a distinct small-RNA fingerprint worth chasing in larger studies.

Subject of Research: Circulating microRNA signatures associated with cachexia in oesophageal squamous cell carcinoma

Article Title: Circulating MicroRNAs Reflect Systemic Inflammation and Metabolic Dysfunction in Oesophageal Squamous Cell Carcinoma–Associated Cachexia

Article References: Li, Y., Chen, R., Lv, X., Wei, S., Xu, Y., & Ding, S. (2026). Circulating MicroRNAs Reflect Systemic Inflammation and Metabolic Dysfunction in Oesophageal Squamous Cell Carcinoma–Associated Cachexia. Journal of Cachexia, Sarcopenia and Muscle, 17(5), Article e70409. https://doi.org/10.1002/jcsm.70409

Image Credits: AI Generated

DOI: 10.1002/jcsm.70409

Keywords: oesophageal squamous cell carcinoma, cancer cachexia, circulating microRNAs, hsa-miR-5187-5p, hsa-miR-4433b-3p, systemic inflammation, biomarkers, plasma qRT-PCR, ROC analysis, overall survival, JAK-STAT signalling, independent validation