Overexpression of miR-138 inhibits proliferation and colony formation, and induces apoptosis of cervical cancer cells. (A) Expression of miR-138 was detected in HeLa cells transfected with miR-138 mimic or miR-NC by quantitative reverse transcription-polymerase chain reaction. (B) Cell proliferation was determined by MTT assay in HeLa cells after being transfected with miR-138 mimic or miR-NC. (C) Colony formation was measured in HeLa cells after being transfected with miR-138 mimic or miR-NC. (D) Apoptosis was detected in HeLa cells after being transfected with miR-138 mimic or miR-NC. **P<0.01 vs. miR-NC. miR-138, microRNA-138; miR-NC, miR-negative control; MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; OD490, optical density at wavelength 490.