目的研究原癌基因受体酪氨酸激酶(recepteurd’origine nantais,RON)对Burkitt淋巴瘤细胞株Raji侵袭性行为的影响及单克隆抗体Zt/f2(2F2)的靶向抑制效应。方法采用RON特异性配体巨噬细胞刺激蛋白(macrophage stimulating protein,MSP)(2.0nmol/L)和Zt/f2(2F2)(2.0nmol/L)处理Raji细胞24和72h,采用MTT比色法研究对Raji细胞增殖的作用;采用甲基纤维素半固体培养法研究对Raji细胞克隆形成的作用;通过Annexin V/PI双染流式细胞术检测对Raji细胞凋亡和细胞周期的影响;采用Westernblot法检测RON的表达和凋亡相关蛋白及周期蛋白的改变。结果与空白对照组细胞活性(1.00)和集落数(103.6±7.0)比较,MSP处理72h后Raft细胞活性为1.35±0.20,集落数为133.7±10.4,而Zt/f2(2F2)单抗处理组细胞活性为0.68±0.11,集落数为66.3±6.1,差异均有统计学意义(P值均〈0.05);Zt/f2(2F2)单独处理组细胞凋亡率为(12.16±2.33)%,G0/G。期细胞所占比例为(54.96±3.70)%,与对照组细胞凋亡率[(2.89±1.03)%]、G0/G1期细胞所占比例[(39.10±2.30)%]比较差异均有统计学意义(P值均〈0.05);Zt/f2(2F2)可以显著降低MSP刺激引起的RON磷酸化水平以及B—catenin蛋白的表达,且使凋亡蛋白caspase-3、-8、-9和多聚ADP核糖聚合酶表达水平增高,抗凋亡基因MCL-1和凋亡抑制蛋白XIAP表达水平下降,而且G.期周期蛋白相应改变。结论RON激活后促进Raji细胞恶性生物学行为;Zt/f2(2F2)可通过抑制Raji细胞RON磷酸化水平改变其G。期周期蛋白和相关凋亡蛋白的表达水平,实现抑制细胞增殖和诱导凋亡的目的。
Objective To study the proto-oncogene RON mediated aggression of Raji cells and the inhibitory effects by monoclonal antibody Zt/f2 (2f2). Methods The effects of RON ligand macro- phage stimulating protein (MSP) (2.0 nmol/L) and inhibitory Zt/f2 (2F2) (2.0 nmol/L) antibody on pro- liferation of RON positive Raji cells after treatment for 24 and72 hours were detected by MTT method, col- ony formation units (CFU) of Raji cells by methylcellulose semi solid culture, Raji cells apoptosis and cell cycle analysis by Annexin V/PI double staining, expression of RON, apoptosis-related proteins, and cyclins by Western blot. Results (1)Compared with the cell viability (1.0) and counts of CFU (103.6±7.0) in control group, Raji cells after MSP treatment had better viability (1.35±0.20) and CFU counts (133.7± 10.4) (P〈0.05), but worse viability (0.68±0.11) and CFU counts (66.3±6.1) after Zt/f2 (2F2) treatment (P〈0.05). (2)Percentage of Raji ceils apoptosis after Zt/f2 (2F2) antibody treatment (12.16±2.33)% was significantly increased than the control (2.89± 1.03)% (P〈0.05). The percentage of Raji cells arrested in G0/G, phase was increased after Zt/f2 (2F2) antibody treatment as compared to the control [ (54.96± 3.70)% vs (39.10±2.30)%, (P〈0.05) ]. (3) High-level of RON phosphorylation and ~-catenin expression activated by MSP could be inhibited significantly by Zt/f2 (2F2), which also up-regulated the expression of caspase-3, caspase-8, caspase-9 and PARP and down-regulated anti-apoptotic MCL-1 gene and inhibitor of apoptosis protein XIAP expression, accompanied with G1 phase protein changes accordingly. Conclusion MSP could aggravate Raji cells proliferation. Inversely, Zt/f2 (2F2) could inhibit proliferation and induce apoptosis by inhibition of RON phosphorylation and up-regulation of apoptosis related proteins.