醋酸甲羟孕酮对人结肠癌LS174T细胞体内生长抑制的作用

Experimental Study of the Inhibitory Effect of Medroxyprogesterone Acetate on the Growth of Human Colon Cancer LS174T Cell Xenografts

目的检测醋酸甲羟孕酮(MPA)对人结肠癌细胞LS174T移植瘤生长的抑制作用并初步分析其机制。方法建立人结肠癌裸鼠皮下移植瘤模型。随机分为3组,每组10只,对照组:静脉注射或以同等容量的生理盐水灌胃;处理组分为MPA治疗组和MPA+5-Fu治疗组,MPA治疗组:每只每次灌胃MPA30mg/kg;MPA+5-Fu治疗组:每只每次静脉注射5-Fu30mg/kg;每只每次MPA30mg/kg灌胃,MPA灌胃每周5次,5-Fu静脉注射每周3次,共用3周。5周后处死动物,切除瘤灶、称瘤重、测瘤体积、计算抑瘤率;标本用流式细胞仪分析移植瘤细胞周期、凋亡率和细胞表面Fas/FasL表达;免疫组织化学SABC法检测移植瘤组织Fas/Fas-L表达。结果对照组、MPA治疗组、MPA+5-Fu合用组肿瘤体积分别为(1.65±0.68)cm3、(0.78±0.31)cm3、(0.23±0.12)cm3;抑瘤率分别为0、52.7%、86.1%。流式细胞仪分析细胞周期,移植瘤LS174T细胞经MPA处理后阻止G1期细胞向S期的进程,S期和G2/M期细胞相对减少,MPA+5-Fu合用组作用更明显。对照组、MPA治疗组、MPA+5-Fu合用组细胞凋亡率分别为3.6%、13.7%、28.6%,MPA作用后移植瘤LS174T细胞表面Fas和FasL表达显著增强。结论MPA对人结肠癌移植瘤LS174T细胞生长具有显著的抑制作用和诱导凋亡作用,其机制可能与MPA使LS174T细胞停滞于G1期及细胞表面Fas和FasL表达上调有关。

Objective To evaluate the efficacy of medroxyprogesterone acetate（MPA） on tumor growth of on human colon cancer xenografts in nude mice. Methods Human colon cancer LS174T cells were inoculated subcutaneously into 30 nude mice, which were then randomized equally into three groups consisting of two treatment groups [a MPA-treated group（n=10） received 30 mg/kg/day MPA via gastrointestinal gavage and a MPA-treated group（n=10） with 5-Fu was administered at 30 mg/kg] and a control group（n=10）. Three groups were treated five times a week for 4 weeks. After treatment ,the mice were sacrificed by cervical dislocation ,and the inhibition effect was measured with the cells cycle and cells surface Fas/FasL expression were analyzed with flow cytometry. And Fas/FasL were examined by immunohistochemical staining with anti-Fas/FasL antibody. Results MPA had significant inhibition effect on the growth of the xenografted tumors. The G0/G1 phase fraction of the xenografted tumors was increased, and the S-phase fracion was decreased after treatment of MPA. Cell surface Fas expression in the xenografted tumors increased after treated with MPA. Fas/FasL expression in the treated tumor tissue ascended noticeably as compared with the controls. Conclusion MPA could significantly suppress the proliferation and induce the apoptosis of the LS174T cell of xenografted tumors by regulating the ceil cycle and apoptoic gene the nude mice.