A Comprehensive Pan-Cancer Analysis Reveals GRB7 as a Potential Diagnostic and Prognostic Biomarker

GRB7 expression was significantly upregulated in bladder urothelial carcinoma (BLCA), cervical squamous cell carcinoma (CESC), cholangiocarcinoma (CHOL), colon adenocarcinoma (COAD), rectum adenocarcinoma (READ), thyroid carcinoma (THCA), and uterine carcinosarcoma (UCEC). Conversely, it was downregulated in kidney chromophobe (KICH) and kidney renal clear cell carcinoma (KIRC) compared to normal tissues (p<0.001). Further analysis confirmed that GRB7 expression in KICH and KIRC was significantly downregulated across various clinicopathological parameters including stage 3 and stage 4 compared to stage 1. It was also significantly downregulated in 61-80 years compared to 41-60 years patients, as confirmed by the immunohistochemistry of kidney tissues. Prognostic analysis revealed that high GRB7 expression was linked to a better prognosis in KIRC and a poorer prognosis in pancreatic adenocarcinoma (PAAD) patients. In KICH, GRB7 expression showed a significant positive correlation with immune infiltration of B cells, CD8+ T cells, and macrophages. In KIRC, GRB7 was positively correlated with immune infiltration of B cells and CD4+ cells. However, in PAAD it was negatively correlated with immune infiltration of macrophages. These findings were validated by gene expression profiling from the Gene Expression Omnibus (GEO) database, confirming a significant GRB7 downregulation in KICH and KIRC and an upregulation in PAAD compared to normal samples. Conclusion: GRB7 shows potential as a biomarker in both diagnosing and predicting outcomes for various cancers. It may serve as a diagnostic marker for KICH, a prognostic marker for PAAD, and both a diagnostic and prognostic marker for KIRC, making GRB7 a target for future research and therapeutic approaches in oncology.