Downregulation of microRNA-142-3p and its tumor suppressor role in gastric cancer

An increasing number of studies indicate that microRNAs (miRNAs) may exert an oncogenic or tumor suppressive role in diverse types of cancer. MicroRNA (miR)-142-3p has been detected to be downregulated in a number of cancer types, and it may function as a tumor suppressor. However, the expression profile and potential role of miR-142-3p in gastric cancer remain unknown. In the present study, the expression of miR-142-3p in numerous gastric cancer samples was investigated. It was observed that miR-142-3p was markedly downregulated in cancer tissues compared with normal tissues. Furthermore, a low expression level of miR-142-3p was associated with higher tumor stages. The overexpression of miR-142-3p was able to inhibit the proliferation, invasion and migration of gastric cancer cells. A further investigation into the mechanism underlying the effect of miR-142-3p identified cyclin T2 (CCNT2) as a target of miR-142-3p in gastric cancers. miR-142-3p may exert its tumor suppressor role partially by downregulating CCNT2. These results suggested that the abnormal downregulation of miR-142-3p and the subsequent increase in CCNT2 expression may have an important role in gastric cancer carcinogenesis.