突变型CD59蛋白对卵巢癌细胞的抑瘤效应

背景与目的：国外报道已在多种实体肿瘤细胞中发现有CD59分子的过表达，并与肿瘤的失控性生长和恶性转化密切相关。本研究探讨突变型CD59在卵巢癌细胞A2780表面的抗补体活性以及与LPS联合抑制A2780细胞增殖的活性。方法：取突变型CD59质粒、野生型CD59质粒分别转染A2780细胞．G418筛选稳定表达细胞克隆，并从基因水平和蛋白水平鉴定CD59突变基因和野生型基因的转染情况。MTT法观察野生型CD59与突变型CD59在A2780细胞表面的抗补体活性，以及突变型CD59在LPS存在时对细胞的抑瘤效应。结果：通过荧光免疫检测、流式细胞术分析、RT—PCR鉴定证明建立了稳定转染野生型和突变型CD59的A2780细胞。MTT结果显示，与野生型CD59相比，突变型CD59失去对补体的抑制功能，与对照组未转染的A2780细胞相比无显著性差异。MTT检测5μg／mLLPS作用30min．对转染野生型CD59、突变型CD59及未转染A2780细胞的增殖抑制率分别为（26．9±2．95）％、（36.3±4．87）％、（29．6±3．16）％，差异有统计学意义（P〈0．05）。结论：CD59的W40位点对其功能具有重要作用，封闭该位点能够提高补体溶细胞作用，并有助于LPS发挥抑制瘤细胞增殖活性．有望应用于肿瘤治疗。

Inhibition of mutant CD59 protein on proliferation of ovarian cancer A2780 cells

Background and Objective： Overexpression of CD59 is found in a variety of solid tumor cells, which is related to the uncontrolled cell growth of tumors and malignant transformation. This study was to investigate the anticomplement capacity of mutant CD59 （at the W40 site）, and its inhibitory effect on ovarian cancer cell line A2780 in combination with lip polysaccharide （LPS）. Methods：The plRES-WTCD59 plasmid and the plRES-M1CD59 plasmid were transfected into A2780 cells. Stable expression clones were selected by G418. CD59 gene and protein were successfully expressed in A2780 cells. The anti-complement capacity of wide-type CD59 and mutant CD59, and the effect of combination treatment with mutant CD59 protein and LPS on A2780 cells were both detected by M-FF assy. Results： Stable expressions of wild type and mutant CD59 were established in A2780 cells. Mutant CD59 lost its inhibition of human complements compared with wide-type CD59 （P〈0.05）, but this was not significantly different compared with the control group. After incubation with 5 mg/L LPS for half an hour, the inhibition rates were （26.9±2.95）%, （36.3±4.87）%, （29.6±3.16）% in A2780 cells transfected with wide-type CD59, mutant CD59, and without transfection respectively （P〈0.05）. Conclusions： The W40 site is important to the activity of human CD59 protein. Inhibition of the W40 site may be a potential method to increase the complement capacity and promote the antiproliferation activity of LPS.