OBJECTIVE

To investigate the effects of autophagy gene Beclin 1 on growth of cervical cancer HeLa cells in vitro and vivo.

METHODS

The eukaryotic expression vector of Beclin1 was constructed and transfected via lipofectamine into HeLa cells. The experimental cells were classified into 3 groups: pcDNA3.1(+)-Beclin1 group,pcDNA3.1(+) group and HeLa group. Real time-ploymerase chain reaction and Western blot were used for detecting expression of Beclin1 mRNA and protein in the transfected cells. Flow cytometry (FCM) was employed to observe the effect of transfection on the apoptosis of HeLa cells, and proliferation was analyzed by MTT assay. The formation of autophagic vacuoles was measured by MDC staining. HeLa cells transfected with plasmid pcDNA3.1(+)-Beclin1 and pcDNA3.1(+) were inoculated subcutaneously in nude mice. The carcinogenic and growth activities of cancer cells in vivo were observed.

RESULTS

Eukaryotic expression vector pcDNA3.1(+)-Beclin1 was constructed successfully. It significantly improved the expression of Beclin1 mRNA and protein in HeLa cells. The proliferation of HeLa cells was inhibited, and the inhibition rate was 58.7%. FCM investigation showed that the apoptotic rate was (28.22 ± 2.34)% of pcDNA3.1(+)-Beclin1 group, significantly higher than the (14.6 ± 4.6)% in the pcDNA3.1(+) group and (11.2 ± 3.0)% in the HeLa group (P < 0.05). The monodansylcadaverin (MDC) staining showed significantly more autophagic vacuoles in the pcDNA3.1(+)-Beclin1 group (10.9%) than that in the pcDNA3.1(+) group (3.1%) and HeLa group (2.5%) (P < 0.05). After transfected with vector pcDNA3.1(+)-Beclin1, the carcinogenic activity of HeLa cells was decreased in nude mice, and the inhibition rate of tumor growth was 52.2%.

CONCLUSIONS

Autophagy gene Beclin 1 overexpression can inhibit the proliferation and growth of HeLa cells in vitro and vivo,while promote autophagy and apoptosis of HeLa cells. So it might be one of new gene therapy strategies for cervical carcinoma.