LncRNA MCM3AP-AS1 Upregulates CDK4 by Sponging miR-545 to Suppress G1 Arrest in Colorectal Cancer

Introduction This study aimed to investigate the role of lncRNA MCM3AP-AS1 in colorectal cancer (CRC). Methods Paired tumor and non-tumor tissues were collected from 60 CRC patients. Expression of MCM3AP-AS1 was determined by RT-qPCR. Overexpression of MCM3AP-AS1, miR-545, and CDK4 in CRC cells was achieved to explore the interactions between them. Cell cycle assay was performed to analyze the roles of MCM3AP-AS1, miR-545, and CDK4 in regulating the cell cycle progression of CRC cells. Results We found that MCM3AP-AS1 was upregulated in CRC and its high expression levels predicted poor survival of CRC patients. MCM3AP-AS1 is predicted to interact with miR-545. In CRC cells, overexpression of MCM3AP-AS1 and miR-545 was achieved, while their overexpression did not affect the expression of each other. Instead, overexpression of MCM3AP-AS1 led to the increased expression levels of CDK4, which is a downstream target of miR-545. Cell cycle analysis showed that overexpression of MCM3AP-AS1 and CDK4 suppressed G1 arrest induced by miR-545. In addition, overexpression of MCM3AP-AS1 reduced the enhancing effects of overexpressing miR-545 on cell cycle progression. Conclusion MCM3AP-AS1 may upregulate CDK4 by sponging miR-545 to induce G1 arrest in CRC cells.