体外Rituximab增敏吉西他滨/长春瑞宾细胞毒作用的实验研究

Rituximab-mediated Sensitization of B-NHL Cell Lines to Apoptosis Induced by Gemcitabine and Navelbine In Vitro

本研究探讨抗CD20单抗利妥昔(Rituximab,RTX)对Gemcitabine和Navelbine的化疗增敏作用及其可能的作用机制。体外培养Daudi、Ramos、Namalwa和Raji细胞,采用XTT法测定细胞增殖抑制率,计算出各自的IC50;比较Gemcitabine或Navelbine单药及Gemcitabine或Navelbine分别与RTX两药协同作用的IC50;用Western blot测定Daudi、Ramos、Raji和Namlwa细胞经RTX20μg/ml作用24小时后抗凋亡蛋白BCL-2的表达情况。结果表明:单药抗CD20单克隆抗体对4株细胞无明显诱导凋亡作用,抑制率在3%-10%之间波动。RTX可使Gemcitabine或Navelbine对Daudi、Namalwa和Raji细胞株的细胞毒作用有明显增强;在Namalwa和Raji细胞株经RTX作用24小时后,BCL-2蛋白表达下调。结论:RTX对新一代细胞毒药物Gemcitabine或Navelbine有明显的细胞毒增敏作用。Namalwa和Raji细胞株经RTX作用24小时后BCL-2表达下调,这可能是RTX增敏细胞毒药物的机制之一。

This study was purposed to explore the Rituximab （RTX）-mediated sensitization of B-NHL cell lines to apoptosis induced by Gemcitabine or Navelbine and its possible mechanism. The inhibitory rate of B-NHL cell proliferation was detected by XTT method, the IC50 from Gemcitabine or Navelbine and combination of Gemcitabine or Navelbine with RTX was compared. The expression level of antiapoptotic protein BCL-2 in Daudi, Ramos, Raji and Namalwa cells treated with RTX of 20 μg/ml for 24 hours was detected by Western blot. The results showed that the RTX as a single agent could weakly induce the apoptosis of Daudi, Namalwa, Raft and Ramos lymphoma cell lines, the inhibiting rate of cell proliferation ranged from 3% to 10% ; RTX could sensitize significantly the cytotoxity of Gemcitabine or Navelbine in Daudi, Namalwa and Raji cell lines; The expression of BCL-2 in Raji and Namalwa cell lines treated with RTX of 20 μg/ml for 24 hours was down-regulated. It is concluded that RTX can sensitize the cytotoxicity of Gemcitabine or Navelbine to the human lymphoma cell lines which displayed the synergistic effect on Daudi, Namalwa and Raji cell lines. The BCL-2 expression level in Raji and Namalwa cell lines treated by RTX is down-regulated which may be one of the mechanisms sensitizing the cytotoxicity of Gemcitabine or Navelbine.