The clinical value, regulatory mechanisms, and gene network of the cancer-testis gene STK31 in pancreatic cancer.

We aimed to identify STK31 as a cancer-testis (CT) gene and to explore its potential clinical value, regulatory mechanisms, and gene network in pancreatic cancer (PC). Gene expression data were generated from normal organ samples and pancreatic cancer samples from three public databases. STK31 expression patterns in normal and PC tissues were identified, and we explored its regulatory mechanisms. Gene ontology (GO) and pathway analyses of STK31-related genes were performed and an STK31 protein-protein interaction (PPI) network was constructed. STK31 was confirmed as a CT gene in PC and its expression was significantly higher in patients with new neoplasm compared with patients without new neoplasm (P = 0.046) and in more advanced pathologic stages than in earlier stages (P = 0.002); methylation level correlated negatively with STK31 expression. In total, 757 STK31-related genes were identified, and were significantly enriched in terms of polymorphisms and alternative splicings. The PPI network predicted that STK31 was physically associated with the PIWI (originally P-element Induced WImpy testis in Drosophila) and Tudor families.