Expression patterns and relevance of UQCRFS1, an emerging prognostic marker in gastric cancer

Background Mitochondrial abnormalities are frequently observed in cancer cells, with the mitochondrial electron transport chain often disrupted during carcinogenesis. However, the expression and clinical significance of mitochondrial complex III subunits, particularly UQCRFS1 , remain poorly understood in gastric cancer (GC). This study investigated the potential of UQCRFS1 as a diagnostic and prognostic molecular marker in GC. Methods Genetic and proteomic analyses were conducted on human gastric tissue samples. UQCRFS1 expression was assessed using polymerase chain reaction (PCR), reverse-transcription PCR, and immunohistochemistry. Additional evaluations included copy number variation (CNV) analysis and DNA methylation profiling of the UQCRFS1 promoter region. Results UQCRFS1 gene expression was significantly upregulated in GC tissues compared to adjacent non-cancerous tissues. A positive correlation was observed between gene and protein expression levels. CNV analysis revealed that UQCRFS1 copy numbers were frequently elevated in GC tissues, and CNV levels were positively correlated with gene expression, T stage, and microsatellite instability status. DNA methylation analysis demonstrated that the majority of GC cases (n = 9/10) exhibited higher methylation levels in the UQCRFS1 promoter region in tumor tissues relative to non-cancerous tissues. Conclusion The overexpression and CNV gain of UQCRFS1 are associated with key clinicopathological features of GC, indicating its potential utility as a prognostic biomarker. These findings provide novel insights into the regulatory role of UQCRFS1 in GC and support its further exploration as a candidate for diagnostic and prognostic applications.