Hypoxia-associated gene signature for uterine cervical cancer

Tumour hypoxia is associated with treatment resistance and adverse outcome in cervical cancer, but clinically robust methods for hypoxia stratification remain limited. We developed and validated a cervical cancer hypoxia-associated gene expression signature derived from experimentally defined hypoxia.

Five cervical cancer cell lines were exposed to normoxia or hypoxia for 24 h and RNA sequencing was used to identify hypoxia-responsive genes. Candidate genes were mapped to the TCGA cervical cancer dataset and used to train a Prediction Analysis for Microarrays classifier. The resulting signature was evaluated in TCGA and externally validated in a retrospective Manchester cohort of patients treated with curative intent, with further validation in two independent public cervical cancer cohorts from South Korea and Norway. Survival analyses were performed using Kaplan-Meier analysis and Cox proportional hazards models.

A 55-gene hypoxia-associated signature was derived from genes consistently upregulated under hypoxic conditions. The gene set was enriched for canonical hypoxia and metabolic processes, including cellular response to hypoxia and glycolysis. In TCGA, hypoxia classification was associated with poorer overall survival and remained independently prognostic after adjustment for clinical stage (HR 2.69, 95% CI 1.29-5.61, p = 0.009). In the Manchester cohort, hypoxic tumours were associated with adverse clinicopathological features, including higher stage, larger tumour size, nodal involvement, and hydronephrosis. Hypoxia classification was associated with inferior progression-free and overall survival and remained independently prognostic for overall survival on multivariable analysis (HR 1.95, 95% CI 1.08-3.51, p = 0.026). Addition of the signature improved model discrimination beyond clinical covariates. External validation confirmed poorer outcomes in hypoxic tumours in the South Korean cohort and Norwegian cohort. In the Norwegian cohort, the Manchester 55-gene signature showed 71% concordance with an independently derived 6-gene hypoxia classifier.

The Manchester 55-gene signature identifies a hypoxia-associated transcriptional phenotype in cervical cancer and is consistently associated with adverse clinical outcome across independent cohorts. Prospective validation using a locked assay and predefined threshold is required before clinical implementation or use in biomarker-stratified trials.