南方红豆杉水提物通过Ras/MAPK信号通路调控HER2阳性胃癌移植瘤生长实验研究

摘要

Objective To investigate the effect of taxus chinensis water extract on human epidermal growth re-ceptor 2(HER2)-positive gastric cancer via regulating Ras/MAPK pathway related proteins. Methods Nude mouse model bearing HER2-positive gastric cancer was established by inoculating NCI-N87 tumor strain. Eighty BALB/c mice were randomized into high-, middle-, low-dose taxus chinensis groups, high-, middle-, low-dose taxus chi-nensis+herceptin groups, and herceptin group and given the corresponding drugs. Mice were killed by cervical dis-location to obtain tumor tissue for inspection. The protein expression of HER2 and KRAS were detected with Western Blot and mRNA contents of the genes were determined by RT-PCR assay. Results Compared with blank group, the expression of HER2 and KRAS proteins were decreased in all drug groups(HER2: 1.238±0.123, 1.180±0.152, 1.159±0.087, 0.876±0.098, 0.651±0.108, 0.554±0.110 vs 1.482±0.101, P<0.05 or P<0.01; KRAS: 0.768±0.040, 0.680±0.019, 0.821±0.170, 0.716±0.023, 0.630±0.049, 0.739±0.044 vs 1.015±0.033, all P<0.05). Compared with that in herceptin group, KRAS protein in middle-dose taxus chinensis+herceptin group was significantly de-creased(0.630±0.049 vs 0.759±0.029, P<0.05). Compared with blank group, the expression of HER2 and KRAS mRNA were decreased in all drug groups(HER2 mRNA: 0.916±0.026, 0.783±0.061, 0.846±0.021, 0.741±0.079, 0.660±0.079, 0.673±0.045 vs 1.000±0.193, all P<0.05;KRAS mRNA: 0.643±0.065, 0.551±0.173, 0.572±0.267, 0.329±0.250, 0.036±0.007, 0.351±0.257 vs 1.001±0.132, P<0.05or P<0.01). Compared with that in herceptin group, KRAS mRNA in middle-dose taxus chinensis+herceptin group was significantly decreased(0.036±0.007 vs 0.362±0.162, P<0.01). Conclusion Taxus chinensis water extract can down regulate the expression of HER2, KRAS protein and mRNA via Ras/MAPK pathway in mice with gastric cancer. When it is combined with herceptin, its anti-tumor effect is enhanced.%目的：探讨南方红豆杉水提物通过抑制Ras/MAPK信号通路相关靶点蛋白表达，调控裸鼠HER2阳性胃癌移植瘤生长及其机制。方法建立荷瘤裸鼠模型，将80只BALB/c裸鼠接种人表皮生长因子-2（HER2）阳性胃癌NCI-N87细胞株，并随机分组给药及取瘤，采用Western Blot检测HER2、KRAS蛋白表达，RT-PCR定量检测HER2、KRAS mRNA表达水平。结果①Western blot检测HER2、KRAS蛋白：与空白组比较，各给药组HER2、KRAS蛋白表达不同程度下调[HER2：（1.238±0.123、1.180±0.152、1.159±0.087、0.876±0.098、0.651±0.108、0.554±0.110）比（1.482±0.101）， P<0.05或P<0.01；KRAS：（0.768±0.040、0.680±0.019、0.821±0.170、0.716±0.023、0.630±0.049、0.739±0.044）比（1.015±0.033），P均<0.05]；与赫赛汀组比较，中剂量联合组KRAS蛋白表达显著下调（0.630±0.049比0.759±0.029，P<0.05）；②RT-PCR检测HER2、KRAS mRNA表达：与空白组比较，各给药组HER2、KRAS mRNA表达不同程度下调[HER2 mRNA：（0.916±0.026、0.783±0.061、0.846±0.021、0.741±0.079、0.660±0.079、0.673±0.045）比（1.000±0.193），P均<0.05；KRAS mRNA：（0.643±0.065、0.551±0.173、0.572±0.267、0.329±0.250、0.036±0.007、0.351±0.257）比（1.001±0.132），P<0.05或P<0.01]；与赫赛汀组比较，中剂量联合组KRAS mRNA表达显著下调（0.036±0.007比0.362±0.162，P<0.01）。结论南方红豆杉水提物可通过Ras/MAPK信号通路部分下调HER2、KRAS蛋白及其mRNA表达水平，联合赫赛汀可增强其抑制作用。