siRNA-mediated inhibition of endogenous brain‑derived neurotrophic factor gene modulates the biological behavior of HeLa cells.

Brain-derived neurotrophic factor (BDNF) is expressed in a number of neural and non-neuronal tumors. The present study investigated the effect of endogenous BDNF on the biological behavior of cervix cancer cells using small interfering RNA (siRNA). HeLa, a cervix cancer cell line with high expression of BDNF, was used as a living model to screen out the effective sequences of short hairpin RNA of the BDNF gene, and the effects of RNA interference on proliferation, apoptosis, migration and invasion of these cells were evaluated. Among the 4 siRNAs examined, siRNA1 caused a 99% reduction in the relative BDNF mRNA level, while a 58% decrease in the relative BDNF protein level (p<0.01) was noted, and thus this siRNA was selected as the most efficient for use in the present study. In subsequent experiments, MTT assay revealed that BDNF silencing caused marked inhibition of HeLa cell proliferation while Hoechst 33258 staining assay demonstrated apoptosis-related changes in cell morphology. Downregulation of BDNF expression induced cell cycle arrest in the G1 phase as shown by flow cytometry. As indicated by Transwell migration and invasion assays, downregulation of BDNF expression suppressed the migratory and invasive capabilities of the HeLa cells. Together, our data revealed that BDNF modulates the proliferation, apoptosis, migratory and invasive capabilities of HeLa cells. BDNF siRNA may represent a novel therapy or drug target for preventing the tumorigenesis of cervical cancer.