Objective To investigate the effect of miR-148a on the chemosensitivity of cervical cancer HeLa cells to cisplatin and its related mechanism.

Methods Cervical cancer HeLa cells were cultured in vitro and the concentration gradient of cisplatin was set to detect IC₂₀ value. Control group, mimic control group, miR-148a mimic group, inhibitor control group and miR-148a inhibitor group were set up. qRT-PCR was used to detect the expression of miR-148a and STAT3 mRNA after transfection. After 4 μmol/L cisplatin treatment, the proliferation of HeLa cells was detected by MTT assay; the apoptosis and cell cycle distribution were detected by flow cytometry; Western blot was used to detect the protein expression of p-STAT3/STAT3, CyclinD1, Bcl-2, Bax and Cleaved caspase-3.

Results The IC₂₀ of cisplatin on HeLa cells was about 4 μmol/L. Compared with the mimic control group, the level of miR-148a in the miR-148a mimic group was significantly increased, and the level of STAT3 mRNA was significantly decreased (P < 0.05). Compared with the inhibitor control group, the level of miR-148a in HeLa cells in miR-148a inhibitor group was significantly decreased, and the level of STAT3 mRNA was significantly increased (P < 0.05). On the basis of cisplatin treatment, compared with the mimic control group, the apoptosis rate, G₀/G₁ phase cell ratio, the protein levels of Bax and Cleaved caspase-3 were significantly increased in miR-148a mimic group, while OD value, the proportions of cells in S and G₂/M phase, the protein levels of p-STAT3/STAT3, CyclinD1, Bcl-2 were significantly decreased (P < 0.05); compared with the inhibitor control group, the above indicators of HeLa cells in miR-148a inhibitor group changed significantly in the opposite direction (P < 0.05).

Conclusion MiR-148a could enhance the chemosensitivity of cervical cancer HeLa cells to cisplatin by targetedly inhibiting STAT3.