MCM5 is an oncogene of colon adenocarcinoma and promotes progression through cell cycle control

Many patients with colon adenocarcinoma (COAD) are diagnosed at an advanced stage, and the molecular mechanism of COAD progression is intricate and controversial. Therefore, there is an urgent need to identify more novel prognosis biomarkers for COAD and elucidate the molecular mechanism of this disease. The present study aimed to screen out key genes correlated with COAD prognosis. In this study, a key module was identified and four hub genes (MCM5 (encoding minichromosome maintenance complex component 5), NOLC1 (encoding nucleolar and coiled-body phosphoprotein 1), MYC (encoding MYC proto-oncogene, BHLH transcription factor), and CDK4 (encoding cyclin dependent kinase 4)) were selected that correlated with COAD prognosis, based on the GSE9348 dataset in Gene Expression Omnibus database. Gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that MCM5 correlated with the cell cycle. Furthermore, MCM5 expression was upregulated in tumor tissues of patients with COAD compared with that in adjacent tissues, based on various databases, including The Cancer Genome Atlas, the Clinical Proteomic Tumor Analysis Consortium database, and the Human Protein Atlas database. Small interfering RNA-mediated knockdown of MCM5 inhibited the cell cycle and migration of colorectal cancer cells in vitro. And western blotting results indicated that factors correlated with cell cycle (CDK2/6, Cyclin D3, P21) were downregulated after knockdown of MCM5 in vitro. Besides, downregulation of MCM5 was demonstrated to inhibit lung metastasis of COAD in nude mice model. In conclusion, MCM5 is an oncogene of COAD that promotes COAD progression via cell cycle control.