(A) Proliferation of the MGC-803 cells in 3 groups, as observed by RTCA. ‘a’ represents the miR-449a upregulation group; proliferation coefficient, 4.282±0.386, P<0.001. ‘b’ represents the control group; proliferation coefficient, 9.002±0.066. ‘c’ represents the miR-449a downregulation group; proliferation coefficient, 9.049±0.073. (B) The relative expression of the CDK6 protein in 3 groups. (C) ‘a’ represents the miR-449a upregulation group; relative expression of CDK6 protein, 21.243±4.097, P<0.001. ‘b’ represents the control group; relative expression, 41.831±1.647. ‘c’ represents the miR-449a downregulation group; relative expression, 67.418±1.369. Relative expression is measured as a percentage and *P<0.05. RTCA, real-time cell analysis; miR, microRNA; CDK6, cyclin-dependent kinase 6.