Abstract:

Objective  To study the effect of nucleolin down-regulation on the biological behaviors of HeLa cells in human cervical carcinoma, including proliferation, apoptosis and invasion. Methods  Four groups were enrolled in the experiment, including the siN1, siN2, and siN3 groups, which targeted human nucleolin gene, and siC group, which served as negative control. The chemically synthetic siRNA was transfected to cervical neoplasm HeLa cell lines in vitro by RNAi Max transfection reagent. The expression of nucleolin mRNA was detected by real time PCR (RT-PCR), and nucleolin protein was evaluated by Western blotting, in order to select the siRNA with the highest transfection efficiency. The proliferative activity of HeLa cells was assessed by Cell Counting Kit-8 (CCK-8) assay; the apoptosis was measured by flow cytometry (FCM) with Annexin V/PI staining; the ability of cellular invasion was tested by Transwell experiment. Results  Sequence-specific siRNAs of nucleolin down-regulated the mRNA levels of nucleolin compared with its negative control siRNA (P<0.05). The protein expression was down-regulated after transfection (P<0.05). The siRNA with the highest transfection efficiency was selected. Compared with the negative control, the proliferative cellular invasion abilities of HeLa cells in the siN2 group were inhibited significantly (P<0.05), while its apoptosis was effectively enhanced (P<0.05). Conclusion  The down-regulated expression of nucleolin mRNA and its protein is able to inhibit cell proliferation and invasion, and promote apoptosis, which indicates gene therapy may be feasible in the treatment of cervical neoplasms.

Key words: Cervix neoplasms; HeLa cells; siRNA; Small interfering; Nucleolin