[Suppressing the growth of Hep-2 human laryngeal cancer cells by silencing survivin gene in vitro and in vivo].

Objective To study the effect of silencing survivin on the growth of Hep-2 human laryngeal cancer cells in vitro and in vivo. Methods Hep-2 cells were transfected with pGCsilencer-siRNA-survivin（psi-survivin）by Lipofectamine 2000. The mRNA and protein expressions of survivin were detected by semi-quantitative RT-PCR and Western blot, respectively. Cell proliferation activity was measured by MTT assay. Apoptosis was assessed by flow cytometry. The implanted tumors were formed from injected Hep-2 cells in nude mice. After the tumor formation, psi-survivin was injected into peritumor tissues. The growth of tumor were observed. The tumor volume was calculated and the tumor growth curve was plotted. The expression of survivin in tumor tissues was detected by Western blot. The tumor cell apoptosis was observed by Tunel stainning. Results The sequence-specific siRNA of survivin inhibited the expressions of survivin mRNA and protein. The inhibition rates of survivin mRNA and protein expression were 54.4% and 37.0%respectively. Also the growth of Hep-2 cells was inhibited significanly,with a decrease by 71.7%. By the day 32 of tumor growth, the mean tumor volumes were （ 1443.9 ± 230.5 ） mm3 （ （-x） ± s ） in saline control group, （ 1348.5 ± 198.4） mm3 in plasmid-negative control group, and （624. 6 ± 188.4） mm3 in psi-survivin group,respectively （t = -5.917 ,P ＜0.01 ）. In the implanted tumors injected with psi-survivin, survivin protein expression was down-regulated significantly,with a inhibition rate of 41.8%. Tunel stainning showed the apoptosis occurred in the implanted tunors. Conclusion Silencing survivin could significantly inhibit the growth of Hep-2 human laryngeal cancer cells in vitro and in vivo. Key words: Gene silencing; Microtubule-associated proteins; Laryngeal neoplasms; Cell line, tumor