基因沉默缺氧诱导因子-1α对BxPC-3细胞株生长、侵袭和凋亡功能的影响

Effect of hypoxia inducible factor-1α gene silencing on cell growth, invasion and apoptosis of BxPC-3 cells

目的观察沉默缺氧诱导因子（HIF）-1α基因表达后，对缺氧微环境下人胰腺癌BxPC-3细胞株生长、侵袭和凋亡功能的影响。方法通过合成短链干扰RNA（siRNA）转染沉默BxPC-3细胞株中HIF-1α基因表达。将细胞分为空白对照组（BxPC-3）、空白质粒转染对照组（GFP）和HIF－1α基因沉默组（sh-HIF-1α），分别在正常环境（21．0％O2）和缺氧环境（0．5％～1．0％02）中培养48h后，描绘各组细胞的生长曲线，并对细胞侵袭性和凋亡率进行检测比较。结果缺氧培养后BxPC-3组和GFP组细胞中HIF-1αmRNA表达分别比正常环境中增加了78．4％和67．6％，相应的HIF．1d蛋白表达分别增加了7．1倍和6．2倍，明显高于sh-HIF-1α组（P〈0．05）。在缺氧环境下，sh-HIF-1α组细胞生长速度慢于BxPC-3组和GFP组（P〈0．05），其穿膜细胞数[（48．8±3．8）个／HP]也明显低于BxPC一3组[（118．0±6．8）个／HP]和GFP组[（116．3±6．4）个/HP，P〈0．01]。相反sh－HIF－1α组细胞在缺氧环境中的凋亡率（20．6±1．3）％明显高于BxPC-3组（2．3±0．3）％和GFP组（2．8±0．9）％（P〈0．01）。结论缺氧可以诱导HIF—1α高表达并提高BxPC－3细胞对缺氧应激的耐受能力，沉默HIF－1α基因表达后，BxPC－3细胞株对缺氧的耐受性显著下降，在缺氧环境中细胞的生长、侵袭能力降低，而缺氧诱导的细胞凋亡明显增加。

Objective To investigate the impact of hypoxia inducible factor （HIF）-1α gene silencing on cell growth, invasion and apoptosis in human pancreatic cancer cell line （BxPC-3） under hypoxia condition. Methods The small interfering RNA （siRNA） was synthesized in order to silence the expression of HIF-1α in BxPC-3 cell line. The cells were divided into three groups： blank control group （BxPC-3）, empty plasmid vector transfection group （GFP） and HIF-1α gene silencing group （sh-HW-1α）. All cells were cultured under either normal （21.0% O2） or hypoxia （0. 5%-1.0% 02 ） condition for 48 h. Then the cell growth curve was plotted. The invasion ability and apoptosis among three groups were compared respectively. Results HIF-lct mRNA expression in BxPC-3 group and GFP group was upregulated by 78.4% and 67. 6% （P 〈0. 05） under hypoxic conditions, and HIF-1α protein level was increased correspondingly （7. 1 folds and 6. 2 folds respectively）. However, HIF-1α expression in sh-HIF-lot group was dramatically reduced as compared with other two control groups （P 〈 0. 05 ）. The cell growth rate in the sh-HIF-lot group was significantly slower than in BxPC-3 and GFP groups （P 〈 0. 05 ）. The number of transmembrane cells in sh-HIF-lot group [ （48.8 ± 3.8 ）/HP] was also less than in BxPC-3 group [ （118.0 ±6. 8）/HP] and GFP group [ （1161 3± 6.4）/HP,P 〈 0. 01 ]. On the contrary, the apoptosis rate induced by hypoxia in sh-HIF-lot group was （20. 6 ± 1.3） %, which was 14. 8 folds as great as that in normoxic conditions, and significantly higher than in BxPC-3 group [ （2. 3 ±0. 3 ） % ] and GFP group [ （2. 8± 0. 9） % ] （P 〈 0. 01 ）. Conclusion Hypoxia could induce the expression of HIF-1 α in BxPC-3 cells and increase the tolerant ability of cells to hypoxia stress. HIF-1α knockout would greatly inhibit the cell growth rate and the invasion ability of BxPC-3 cells, and the apoptosis rate induced by hypoxia was significantly enhanced.