ABSTRACT
Cancer of the colon and rectum are two distinct entities, which require different treatment strategies and separate treatment. MicroRNAs (miRNAs) act as critical regulators of genes involved in several biological processes. Aberrant alterations of miRNAs have been found in several types of cancer, including colon cancer and rectal cancer. Extensive catalogues of downregulated miRNAs have been identified for colon cancer, whereas only limited data are available for rectal cancer. An example of miRNA profiling in a previous study found that miRNA (miR)144 showed aberrant expression and appeared to be rectal cancerspecific, its expression not being reported in colon cancer. In the present study, the role of miR144 in rectal cancer was investigated. SW837 and SW1463 cell lines were selected as rectal cell carcinoma cells. Using reverse transcription-quantitative polymerase chain reaction, western blot, BrdU, cell migration and cell viability assays, it was found that the expression levels of miR144 were significantly reduced in the SW837 and SW1463 cell lines, and the overexpression of miR144 suppressed rectal cancer cell viability, migration and proliferation. In addition, Rhoassociated coiledcoil containing protein kinase 1 (ROCK1) was identified as a target of miR144 in the rectal cancer cells. The supplementation of ROCK1 markedly restored the cell migration and proliferation, which was inhibited by miR144. Together, the data of the present study demonstrated that miR144 acts as a tumor suppressor by targeting ROCK1, and indicates the potential of miR144 as a novel biomarker and target in the treatment of rectal cancer.
