目的: 探讨嵌合抗CD20抗体Fab′片段的抗肿瘤机制。方法: 应用MTT法检测Fab′片段对Raji细胞生长的抑制作用，用Annexin V-FITC和PI测定Fab′片段对Raji细胞凋亡的诱导作用，用RT-PCR和Western blot检测Raji细胞中bcl-2表达的变化。结果: 嵌合抗CD20Fab′片段对Raji细胞具有明显的抑制作用IC50值为24.2 μg/ml，并呈剂量依赖性；嵌合抗CD20 Fab′片段能诱导Raji细胞的凋亡，并降低Raji细胞中bcl-2基因及其蛋白的表达水平。 结论:嵌合抗CD20抗体片段Fab′能抑制Raji细胞生长和诱导细胞凋亡，其作用机制与bcl-2蛋白表达的下降有关

Objective:To study anti-tumor mechanism of chimeric anti-CD20 antibody fragment Fab′ in vitro. Methods：The effect of anti-CD20 antibody fragment Fab′ on Raji cells growth was observed using MTT; Annexin V-FITC and PI were used to assay Raji cells apoptosis induced by Fab′; bcl-2 gene expression level change in Raji cells induced by Fab′ was assayed using RT-PCR and Western blotting. Results：The result of MTT indicated that the growth of Raji cells was inhibited by chimeric anti-CD20 antibody fragment Fab′ (IC50, 24.2 μg/ml); bcl-2 gene expression level in Raji cells was decreased prominently by Fab′. Conclusions： It is relative between growth inhibition of Raji cells and apoptosis induced by chimeric anti-CD20 antibody fragment Fab′, and bcl-2 level decline was involved.

国家高技术研究发展专项经费资助（中试基金国科生字2000141和20001AA215341）；天津重大基金(003119511)资助项目