Cancer-associated fibroblasts reveal aberrant DNA methylation across different types of cancer

Cancer-associated fibroblasts (CAFs) are essential components of the tumor microenvironment and play a critical role in cancer progression. Numerous studies have identified significant molecular differences between CAFs and normal tissue-associated fibroblasts (NAFs). In this study, we isolated CAFs and NAFs from liver tumors and conducted a comprehensive analysis of their DNA methylation profiles, integrating our finding with data from studies on other cancer types. Our analysis revealed that several CAF samples exhibited aberrant DNA methylation patterns, which corresponded with altered gene expression levels. Notably, DNA methylation at liver CAF-specific CpG sites was linked to survival outcomes in liver cancer datasets. An integrative analysis using publicly available datasets from various cancer types, including lung, prostate, esophageal, and gastric cancers, uncovered common epigenetic abnormalities across these cancers. Among the consistently altered CpGs were cg09809672 (EDARADD), cg07134930 (HDAC4), and cg05935904 (intergenic). These methylation changes were associated with prognosis across multiple cancer types. The activation of CAFs by the tumor microenvironment seems to be associated with distinct epigenetic modifications. Remarkably, similar genomic regions tend to undergo hypomethylation in CAFs across different studies and cancer types. Our findings suggest that CAF-associated DNA methylation changes hold potential as prognostic biomarkers. However, further research and validation are necessary to develop and apply such signatures in a clinical setting.