Mechanisms of silencing hypoixa inducible factor-2α gene with siRNA on apoptosis of human gastric carcinoma cell line SGC7901

Objective To observe the Mechanisms of silencing hypoixa inducible factor-2a（HIF-2a） gene on apoptosis of human gastric carcinoma cell lines SGC7901. Methods Human gastric car- cinoma cell lines SGC7901 were cultured in vitro. The expression of HIF-2a, B lymphocytes/leukemia-2 （ bcl-2）, bcl-2 associated＂ X protein （ bax）, cysteinyl aspartate-specific protease （Caspase） -3 were detected by real-time fluorescent quantitative polymerase chain reaction （FQ-PCR） and Western blotting in normal or under hypoxia （90% N2 ＋ 5% H2 ＋ 5% CO2 ）. Transfection effect of HIF-2a-small interfering RNA （siRNA） was detected by Western blotting, cell counting kit （CCK） was used to test the cell proliferation and flow cytometry （FCM） was used to test the cell apoptosis rates after transfection of HIF-2a-siRNA. And the ex- pression of bcl-2, bax, Caspase-3 were detected by FQ-PCR and Western blotting. Results The expres- sion of HIF-2a mRNA and protein （2. 94 -0. 31, 0. 61 ＋0. 08）, bel-2 mRNA and protein （2. O1 _＋0. 29, 1.05 ± 0. 09 ） increased and the expression of bax mRNA and protein （0. 54 ±0. 06, 0. 48 ± 0. 05 ） , Caspase-3 mRNA and protein （0.45 ±O. 05, 0. 58± 0. 07） decreased under hypoxia than under normal condition of fqlF-2a （1.06 ±0. 15, 0.23 ＋0.04）, bcl-2 （1.08 ±0. 16, 0.34 ±0.05）, bax （0.97 ＋ 0.13, 0.74±0.12） and Caspase-3 （0.96 ＋0.12, 0.89±0.14） mRNA and protein （P〈0.05）. HIF-2a expression was suppressed after HIF-2oL-siRNA transfection. The proliferation [（0.47 ＋ 0.05 ） %] decreased, the cell apoptosis rates [（20. 16 ＋ 3.09 ）%] increased after HIF-2a-siRNA transfeetion [（0.89＋0.12）%, （8.15 ＋0.97）%, P〈0.05]. bel-2 mRNA and protein （0.43HIF-2a-siRNA transfeetion [（0.89＋0.12）%, （8.15 ＋0.97）%, P〈0.05]. bel-2 mRNA and protein （0.43_＋0.06, 0.78 ＋ 0. 12） decreased, bax mRNA and protein （2. 91 ± 0. 28, 1.51 ＋ 0. 28 ）, Caspase-3 mRNA and protein （2. 42 ±0. 34, 1.34 ± 0. 21 ）inereased after HIF-2a-siRNA transfeetion （0. 96 ＋ 0. 09, 1.37 ＋ 0. 21, 1.13＋0.19, 0.82 ±0.16, 0.97 ±0.13, 0.69 ±0.11） （P〈0.05）. Conclusion Under hypoxia,HIF-2a-siRNA could decrease the expression of bcl-2, increase the expression of bax, Caspase-3, and induce apoptosis.0.06, 0.78 ＋ 0. 12） decreased, bax mRNA and protein （2. 91 ± 0. 28, 1.51 ＋ 0. 28 ）, Caspase-3 mRNA and protein （2. 42 ±0. 34, 1.34 ± 0. 21 ）inereased after HIF-2a-siRNA transfeetion （0. 96 ＋ 0. 09, 1.37 ＋ 0. 21, 1.13＋0.19, 0.82 ±0.16, 0.97 ±0.13, 0.69 ±0.11） （P〈0.05）. Conclusion Under hypoxia,HIF-2c~-siRNA could decrease the expression of bcl-2, increase the expression of bax, Caspase-3, and induce apoptosis. Key words: Hypoixa inducible factor-2a;  Gastric carcinoma;  RNA interference;  Apoptosis