沉默HMGB1基因对裸鼠人上皮性卵巢癌移植瘤生长的抑制作用

Inhibitory effect of silencing HMGB1 gene on growth of human epithelial ovarian cancer xenografts in nude mice

目的:探讨高迁移率族蛋白B1(high mobility group box 1,HMGB1)基因对裸鼠人上皮性卵巢癌移植瘤生长的影响。方法:选取对数生长期的人上皮性卵巢癌细胞株SKOV3细胞建立裸鼠人上皮性卵巢癌移植瘤模型,将造模成功的裸鼠随机分成对照组和HMGB1-siRNA组,分别在接种细胞后第7、9、11、14、16天于荷瘤鼠腋下注射等量的生理盐水和HMGB1-siRNA。3周后颈椎脱臼法处死裸鼠、分离肿瘤组织,测量肿瘤的体积并绘制肿瘤生长曲线,以Tunel染色法检测移植瘤细胞的凋亡情况,Western blotting检测移植瘤组织中HMGB1、STAT3、p-STAT3的表达水平,免疫组化染色技术检测移植瘤组织中VEGF-A的表达和微血管形成情况。结果:与对照组相比,HMGB1-siRNA组的肿瘤体积增长速度减缓,第21天起HMGB1-siRNA组的肿瘤体积显著小于对照组(P<0.05);HMGB1-siRNA成功敲降了移植瘤组织细胞中HMGB1 mRNA的表达,移植瘤组织中HMGB1-siRNA组的细胞凋亡率较对照组显著升高[(34±8)%vs(6±2)%,P=0.04],HMGB1和p-STAT3表达显著降低(P<0.05),VEGF-A表达和微血管数均显著低于对照组(均P<0.05)。结论:敲降HMGB1基因可能通过抑制HMGB1/STAT3信号通路降低VEGF-A的表达和微血管形成,从而促进肿瘤组织细胞凋亡和减缓移植瘤生长。

Objective:To investigate the effect of HMGB1 gene on the growth of human epithelial ovarian cancer xenografts in nude mice,and to lay a foundation for finding new targets for the treatment of ovarian cancer.Methods:Human epithelial ovarian cancer SKOV3 cells in logarithmic growth phase were selected to establish a human epithelial ovarian cancer xenograft model in nude mice.Nude mice with successful model establishment were randomly divided into control group and HMGB1-siRNA group.On the 7th,9th,11th,14th,and 16th days after cell inoculation,the same amount of saline and HMGB1-siRNA were respectively injected into two groups of mice under the armpit.After 3 weeks,the nude mice were sacrificed by cervical dislocation,the tumor tissues were separated,and the volume of the tumor was measured.The apoptosis of transplanted tumor cells was detected by Tunnel staining.The expressions of HMGB1,STAT3 and p-STAT3 were detected by Western blotting.The expression of vascular endothelial growth factor A(VEGF-A)and microvascularization were detected by immunohistochemistry.Results:Compared with the control group,the growth of tumor volume slowed down in HMGB1 siRNA group,and on the 21st day,the tumor volume of HMGB1-siRNA group was significantly smaller than that of the control group(P<0.05).HMGB1-siRNA successfully knocked down the expression of HMGB1 mRNA in transplanted tumor tissue.The apoptosis rate of tissue cells in HMGB1-siRNA group was significantly increased([34±8]%vs[6±2]%,P=0.04),and the expressions of HMGB1 and p-STAT3 were significantly reduced(P<0.05).The expression of VEGF-A and the number of microvessels were significantly lower than those of the control group(both P<0.05).Conclusion:Knockdown of HMGB1 gene reduces the expression of VEGF-A and microvessel formation possibly by inhibiting the HMGB1/STAT3 signaling pathway,thereby promoting the apoptosis of tumor tissues and slowing the growth of xenografts.