5-氮杂-2'-脱氧胞苷联合紫杉醇与氟尿嘧啶对人胃癌细胞系MKN-45裸鼠移植瘤生长的抑制作用

Inhibitive effects of 5-aza-2'-deoxycytidine combined with paclitaxel and fluorouracil on nude mice xenograft growth of human gastric cancer cell line MKN-45

目的探讨5-氮杂-2'-脱氧胞苷(5-Aza)联合临床化疗药物紫杉醇与氟尿嘧啶对于胃癌裸鼠移植瘤生长的抑制作用和抑癌基因RUNX3 mRNA以及肿瘤转移相关蛋白E-cadherin与Vimentin表达的影响。方法建立胃癌细胞株MKN-45的裸鼠移植瘤模型,分为0.9%氯化钠注射溶液对照、5-Aza(2 mg/kg,每天1次)、化疗药物(1 mg/kg紫杉醇与5 mg/kg氟尿嘧啶,分别于治疗周期第1、8天用)以及5-Aza与紫杉醇及氟尿嘧啶联合用药,采用腹腔注射方法给药3周。观察各组裸鼠移植瘤的生长速度变化,并用RT-PCR方法检测肿瘤RUNX3基因的mRNA表达水平,免疫组织化学方法检测E-cadherin与Vimentin表达情况。结果胃癌细胞MKN-45裸鼠移植瘤模型经药物治疗3周后,与空白对照组相比,5-Aza组或T+F组的移植瘤生长速度明显减慢(P<0.05),而且5-Aza与T+F联合治疗组比单独处理组的肿瘤生长速度下降更为显著(P<0.05)。通过作用机制分析发现,与对照组相比,化疗药物T+F组RUNX3 mRNA及E-cadherin与Vimentin蛋白表达水平无明显变化;5-Aza处理组RUNX3 mRNA与E-cadherin蛋白表达水平有明显升高,Vimentin表达水平有明显下降;药物联合组RUNX3 mRNA与E-cadherin蛋白表达水平升高明显,而Vimentin表达水平下降更为显著。结论 5-Aza具有抑制胃癌裸鼠移植瘤生长与转移的能力,联合化疗药物紫杉醇与氟尿嘧啶处理效果更显著。5-Aza发挥肿瘤抑制功能可能是通过提高抑癌基因RUNX3基因表达实现的。

Objective To explore the influence of tumor growth inhibition and RUNX3 mRNA and E-cadherin and Vimentin protein expression of gastric cancer nude mice xenograft by 5-aza-2＇-deoxycytidine（5-Aza） combined with clinical chemotherapy drug paclitaxel and fluorouracil.Methods Nude mice models bearing gastric cancer cell line MKN-45 xenograft were established and divided into saline control,5-Aza（daily 2 mg / kg）,chemotherapy（1 mg / kg paclitaxel and 5mg / kg fluorouracil,with 1,8 days in the treatment cycle）,and 5-Aza combination with paclitaxel and fluorouracil,administered by intraperitoneal injection method for 3 weeks.Tumor xenograft growth rate changes were observed,and tumor RUNX3 gene mRNA expression was detected by RT-PCR method and E-cadherin and Vimentin expression was assayed by immunohistochemistry.Results Compared with the control group,the tumor growth slowed significantly in 5-Aza group or T ＋ F group after nude mice models bearing gastric cancer cell line MKN-45 xenograft were treated for 3 weeks（P 0.05）.Moreover,the tumor growth in the group treated by 5-Aza and T ＋ F combination therapy decreased more significantly than that of single drug group（P 0.05）.RUNX3 mRNA and Ecadherin and Vimentin protein expression had no significant changes in chemotherapy drugs T ＋ F group compared with control group.RUNX3 mRNA and E-cadherin protein levels increased significantly and Vimentin expression decreased significantly in 5-Aza treatment group.In drug combination group,RUNX3 mRNA and E-cadherin protein levels increased significantly,while Vimentin expression levels decreased more significantly.Conclusion 5-Aza can inhibit the growth of gastric cancer xenografts in nude mice,and the effect is more remarkable when combined with chemotherapy drugs paclitaxel and fluorouracil,which may be through increasing RUNX3gene expression.