Elevated TMC8 expression correlates with CD8+ T cell infiltration and favorable survival in oral squamous cell carcinoma.

BACKGROUND

Oral squamous cell carcinoma (OSCC) outcomes are fundamentally dictated by complex interactions within the tumor immune microenvironment. Elevated expression of transmembrane channel-like 8 (TMC8) has been correlated with favorable survival across various solid tumors. However, it remains undetermined whether this prognostic benefit reflects a tumor-suppressive cellular function or a broader microenvironmental crosstalk. This study aimed to investigate the cell-autonomous role of TMC8 in OSCC and explore its broader immunological crosstalk within the tumor microenvironment (TME).

METHODS

The present study integrated large-scale immunogenomic analyses of 315 clinical samples with in vitro functional assays and topological network mapping. Targeted gene silencing in pure OSCC cell lines was conducted to evaluate cell-autonomous behaviors, including proliferation and invasion. The macroscopic immunological landscape was stratified utilizing multidimensional deconvolution algorithms, and the predicted intercellular communication was explored through protein-protein interaction networks and unsupervised co-expression matrices.

RESULTS

While TMC8 was significantly upregulated in malignant tissues, elevated expression strongly predicted prolonged overall and progression-free survival. In vitro assessments demonstrated that silencing this target attenuated malignant cellular phenotypes, suggesting a pro-tumorigenic role in vitro. Conversely, clinical macro-omics analyses revealed that elevated expression of this transmembrane protein was strongly associated with a CD8+ T cell-enriched inflamed microenvironment. Bioinformatics network mapping predicted that TMC8 was co-expressed and potentially associated with the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) innate sensing network and subsequent inflammatory cascades, rather than functioning as a direct source of terminal chemokines.

CONCLUSIONS

The intrinsic cellular pro-tumorigenic role of TMC8 might be counterbalanced by its potential association with danger-sensing networks. This potential network association could be linked to a multicellular inflammatory crosstalk that correlates with cytotoxic T lymphocyte recruitment, providing a plausible hypothesis for the paradoxical survival benefit and highlighting its value as a prognostic biomarker.