Abstract
The present study aimed to evaluate the effect of the expression of the autophagic gene beclin 1 on the biological behavior and chemotherapy sensitivity towards Taxol® of cervical cancer HeLa cells. A beclin 1 expression vector was constructed and tranfected into HeLa cells. Reverse transcription-polymerase chain reaction and western blotting were used to detect the expression of beclin 1. Cell proliferation was detected based on the growth curve of the cells. The effect of beclin 1 expression on cell apoptosis was analyzed using Hoechst 33258 staining, which enabled to observe the morphology of apoptotic cells. Apoptosis-associated proteins were measured by western blot assay. The sensitivity of HeLa cells to Taxol® was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Beclin 1 expression at the messenger RNA and protein levels was elevated following transfection of the beclin 1 expression plasmid (P<0.05). Hoechst 33258 staining revealed that the apoptosis rate of the transfected HeLa cells was significantly higher than that of normal HeLa cells. The expression of caspase-3 was increased in the transfected cells, and beclin 1 transfection increased B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax):Bcl-2 ratio, resulting in Bax activation and Bcl-2 suppression (P<0.05). Chemotherapy sensitivity analysis demonstrated that the half maximal inhibitory concentration values of Taxol® of the transfection, non-transfection and mock-vehicle groups were 30.4, 118.0 and 125.5 µg/ml, respectively. Beclin 1 inhibited proliferation and increased apoptosis of HeLa cells, and also increased the chemosensitivity of these cells to Taxol®. The present results confirmed that beclin 1 is a favorable prognostic biomarker for cervical cancer treatment, and may serve to identify particular patients for individual therapy.