Identification of lipid metabolism-related marker genes in colorectal cancer.

OBJECTIVE

To identify lipid metabolism associated biomarkers in colorectal cancer (CRC).

METHODS

To refine our list of candidate genes, we utilized the Molecular Complex Detection (MCODE) plug-in within Cytoscape software and performed protein-protein interaction (PPI) network analysis to extract hub genes centrally located within the networks, which potentially possess important regulatory functions. Hub gene-associated miRNAs and transcription factors (TFs) were analyzed using miRNet. Immunohistochemical staining was employed to verify the expression levels of hub genes in clinical CRC tissues. Concurrently, cellular experiments were designed to explore the functional roles of the hub gene DHCR7 at the cellular level, providing scientific evidence for the precision treatment of CRC.

RESULTS

A total of 9008 differentially expressed genes (DEGs) were identified between CRC and control samples. Gene Set Enrichment Analysis (GSEA) revealed that these DEGs were mainly enriched in biological processes such as myogenesis, adipogenesis, oxidative phosphorylation, and fatty acid metabolism. Using Weighted Gene Co-expression Network Analysis (WGCNA), we found that the pink and yellow modules were most significantly associated with CRC. Cytoscape analysis identified six hub genes (DHCR7, FABP4, FASN, FAXDC2, PTGIS, SLC27A6). Their diagnostic performance was verified in the external GSE23878 dataset. Clinical studies showed a downregulation trend in the expression of FAXDC2 and PTGIS in CRC tissue samples, while FASN and DHCR7 were up-regulated in colon cancer tissues. However, the expression trend of FABP4 was inconsistent with previous bioinformatics predictions. Further cellular experimental results demonstrated that DHCR7 knockdown significantly inhibited CRC cell proliferation and induced apoptosis, which strongly supported the previous bioinformatics analysis.

CONCLUSION

Our research successfully identified six hub genes in CRC through a series of rigorous analyses and experimental validations. These findings provide important molecular basis for further investigation into the pathogenesis and progression of CRC.