小剂量长春新碱和恩度联合用药对横纹肌肉瘤皮下移植瘤的抑制作用

Combined application of small dosages of vincristine and endostar inhibits transplanted rhabdomyosarcoma in nude mice

目的研究小剂量长春新碱(Vincristine,VCR)和恩度(Endostar,Endo)联合用药对横纹肌肉瘤(Rhabdomyosarcoma,RMS)BALB/c裸鼠皮下移植瘤的生长抑制作用,并探讨其机制。方法经BALB/c裸鼠右侧腋部皮下注射RMS细胞PLA-802悬液,建立RMS的皮下移植瘤动物模型;接种RMS后第8天,将选模成功的裸鼠随机分为对照组(注射生理盐水)、VCR组、Endo组和联合组,注射部位均为腹腔,注射体积均为0.2 ml/(只.日),每3 d称重1次,并测量肿瘤的长短径,计算肿瘤体积,绘制肿瘤生长曲线,2周后处死裸鼠,称量瘤重,并计算抑瘤率;RT-PCR和Western blot法检测移植瘤细胞中血管内皮生长因子(Vascular endothelial growth factor,VEGF)基因mRNA的转录水平和蛋白的表达水平;免疫组化法检测VEGF和CD31的分布和表达。结果裸鼠接种PLA-802细胞第8天,RMS裸鼠模型复制成功,裸鼠成瘤率为84%(42/50);联合组裸鼠体重和移植瘤的体积、重量均明显小于对照组、VCR组和Endo组(P<0.01);VCR组、Endo组和联合组抑瘤率分别为31.41%、20.75%和48.41%;与对照组相比,VCR组、Endo组和联合组裸鼠移植瘤细胞中VEGF基因mRNA的转录水平和蛋白表达水平均显著下降,且以联合组下降最明显(P<0.05);免疫组化结果显示,联合组VEGF和CD31的表达水平明显低于其他3组。结论小剂量VCR和Endo对RMS的皮下移植瘤的生长具有明显的抑制作用,而联合用药能起到增效作用,其机制可能是通过抑制肿瘤的血管生成而发挥其抑制作用。

Objective To observe the inhibitory effect of combined application of vincristin（VCR） and endostar（Endo） on growth of subcutaneously transplanted rhabdomyosarcoma（RMS） in nude BALB / c mice and investigate the relevant mechanism.Methods Nude mouse model of subcutaneously transplanted RMS was established by s.c.injection with the suspension of RMS PLA-802 cells into the right armpits of nude BALB / c mice.The model nude mice were randomly divided into one control and three test groups on day 8 after transplantation of RMS.The nude mice in three test control groups were injected i.p.with VCR,Endo and VCR ＋ Endo respectively,each at a dosage of 0.2 ml,once a day for 2 weeks,while those in control group with physiological saline.The nude mice were weighed every 3 d,of which the tumors were measured for longitudinal and transverse diameters,based on which the sizes of tumors were calculated,and the tumor growth curve was plotted.The nude mice were killed 2 weeks after the first injection,of which the tumors were weighed,and the tumor inhibition rates were calculated.The transcription level of vascular endothelial growth factor（VEGF） mRNA in transplanted tumor cells was determined by RT-PCR,while the expression level of VEGF by Western blot.The distributions and expressions of VEGF and CD31 were determined by immunohistochemical assay.Results Nude mouse model of EMS was copied successfully on day 8 after inoculation with PLA-802 cells,with a tumor formation rate of 84%（42 / 50）.The bodyweights of nude mice in VCR ＋ Endo group were significantly lower,while the sizes of transplanted tumors were significantly smaller,than those in control,VCR and Endo groups（P〈0.01）.The tumor inhibition rates in VCR,Endo and VCR ＋ Endo groups were 31.41%,20.75,% and 48.41% respectively.Compared with those in control group,both the transcription levels of VEGF mRNA and expression levels of VEGF in VCR,Endo and VCR ＋ Endo groups decreased significantly,of which those in VCR ＋ Endo group were the lowest（P〈0.05）.Immunohistochemical assay showed that the expression levels of VEGF and CD31 were significantly lower in VCR ＋ Endo group than in the other three groups.Conclusion The VCR and Endo at small dosages significantly inhibit the growth of transplanted RMS,while combined application of the two drugs enhanced the inhibition by a possible mechanism of inhibiting the angiogenesis of tumor.