表皮生长因子受体抑制剂埃罗替尼对胰腺癌血管生成的影响

The effects of Erlotinib,an epidermal growth factor receptor inhibitor,on the angiogenesis of pancreatic cancer

目的观察表皮生长因子受体抑制剂埃罗替尼对胰腺癌新生血管生成的影响,探讨其对胰腺癌生长抑制的作用机制。方法①应用小管形成实验观察埃罗替尼(终浓度100μmol/L)对血管生成的影响,并与对照组(加入无血清培养液)进行比较。②建立胰腺癌细胞株BxPC-3裸鼠移植瘤模型,用埃罗替尼灌胃,每天100 mg/kg,共4周。每周测量移植瘤体积,4周后处死裸鼠,计算抑瘤率,并与未用埃罗替尼对照组裸鼠比较。RT-PCR法检测不同浓度(5、50、100、200μmol/L)埃罗替尼处理后BxPC-3细胞血管内皮生长因子(VEGF)表达的变化。采用Ⅷ因子免疫组化染色评估瘤组织中微血管密度(MVD)。结果小管形成实验中,埃罗替尼组细胞数显著少于对照组,中空闭合管状结构缺如。埃罗替尼灌胃4周后,治疗组平均瘤重(0.397±0.550)g,显著低于对照组的(1.570±1.060)g,抑瘤率为74.5%。浓度≥50μmol/L的埃罗替尼各组BxPC-3细胞中VEGF mRNA相对表达量较对照组下调,移植瘤组织VEGF表达亦较对照组显著下调.瘤组织MVD(1.86±0.43)显著低于对照组(5.98±1.27,P<0.01)。结论埃罗替尼可抑制裸鼠移植瘤生长和胰腺癌体内、体外血管的生成,可作为胰腺癌的辅助治疗方法之一。

Objective To investigate the mechanisms of inhibitory effect of Erlotinib, an epidermal growth factor（VEGF） receptor inhibitor, on angiogenesis of pancreatic carncer. Methods ① In a tube formation assay, Erlotinib（ 100 μmol/L） was applied to the culture media and compared to the serum free media. The expression of vascular endothelial growth factor（VEGF） in BxPC-3 cells treated with Erlo- tinib at different concentrations（5, 50, 100, 200 μmol/L） was determined by RT-PCR. ② The xenografts derived from BxPC-3 cancer cells were inoculated into the BALB/C nude mice. The mice were treated with either Erlotinib（100 mg/kg of Erlotinib oral lavage daily） or saline for four weeks. The volume of the xenografts was measured and the tumor growth rate was calculated, The microvessel density （MVD） of tumor tissue was determined by immunohistochemistry with an antibody against factor Ⅶ. Results There were less endothelium cells and close hollow tubular structures in Erlotinib treated group compared to the control group in the tube formation assay. The mean weight of xenografts in Erlotinib treated group[（0. 397± 0. 550）g] was significantly lower than that in the control group[（1. 570 ± 1.060）g] with a inhibitary rate of 74. 5%. The expression of VEGF mRNA in Erlotinib treated groups （= 50 μmol/L） were decreased comparing to the control group. The VEGF expression in xenografts tumor tissues was also markedly down-regulated. The MVD was significantly decreased in Erlotinib treated group（ 1.86 ±0.43）than that in the control group（5. 98 ±1.27, P 〈 0.01）. Conclusions Erlotinib can inhibit the growth of xenografts and angiogenesis of pancreatic cancer both in vitro and in vivo, which can be used as a neoadjuvant in treatment of pancreatic cancer.