Overexpression of BUB1B, CCNA2, CDC20 and CDK1 in tumor tissues predicts poor survival in pancreatic ductal adenocarcinoma.

Overexpressed genes in tumors usually contributed to aggressiveness in pancreatic ductal adenocarcinoma (PDAC). Using Gene Expression Omnibus (GEO) profiles including GSE46234, GSE71989 and GSE107610, we detected overexpressed genes in tumors with R program, which were enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene ontology (GO) and Reactome pathway databases. Then, we performed a survival analysis of enriched genes based on TCGA profile. Our results revealed that high BUB1B, CCNA2, CDC20 and CDK1 expression in tumors was significantly associated with worse overall survival (OS) (Log rank P = 0.00338, P = 0.0447, P = 0.00965 and P = 0.00479, respectively), which was validated using a Kaplan-Meier Plotter with a median cutoff (Log rank P = 0.028, P = 0.0035, P = 0.039 and P = 0.0033, respectively). Moreover, overexpression of BUB1B, CCNA2, CDC20 and CDK1 in tumor tissues was significantly associated with disease-free survival (DFS) in PDAC patients (Log rank P = 0.00565, P = 0.0357, P = 0.00104 and P = 0.00121, respectively). BUB1B, CCNA2, CDC20 and CDK1 were significantly overexpressed in deceased PDAC patients (All P < 0.01) and in patients with recurrence/disease progression (All P < 0.05). In addition, PDAC patients with neoplasms of histologic grade G3-4 had significantly higher BUB1B, CCNA2 and CDC20 levels (All P < 0.05). In conclusion, the upregulation of BUB1B, CCNA2, CDC20, CDK1 and WEE1 in tumor tissues are associated with worse OS and DFS in PDAC and is correlated with advanced tumor stage and tumor development.