miR-21 Regulates the Growth of Gastric Cancer Cells Through Targeting Phosphatase and Tensin Homolog (PTEN)

Gastric cancer (GC) is the leading cause of death worldwide and the prognosis remains poor. Proliferation and apoptosis of cancer cells are regulated by microRNAs (miRNAs). We herein intended to explore the interaction of miR-21 and PTEN in GC. miR-21 inhibitor or negative control was transfected into GC cells MGC-803 followed by analysis of miR-21 and PTEN level by RT-qPCR, PTEN protein level by western blot and cell growth by MTT and Hoechest-33342 staining. Treatment with miR-21 inhibitor reduced miR-21 expression and increased PTEN protein expression. miR-21 was negatively associated with PTEN level. Moreover, downregulation of miR-21 decreased cell proliferation and promoted apoptosis. In conclusion, miR-21 stimulates the malignant phenotypes of GC cells by negatively regulating PTEN expression, providing novel insight into the pathogenesis of gastric cancer.