富含脯氨酸和谷氨酰胺的剪切因子:预测血液肿瘤耐药的潜在靶点

 【摘要】　目的　鉴定血液肿瘤细胞耐药相关膜抗原，探讨其在血液肿瘤细胞膜易位表达的普遍性。方法　以蛋白电泳和免疫共沉淀法分离并沉淀细胞膜抗原，以质谱分析鉴定抗原信息，通过siRNA基因干扰法和激光共聚焦显微镜法确证抗原信息及其易位细胞膜的鉴定结果，通过流式细胞术检测抗原在多种血液肿瘤细胞膜的易位表达。结果　免疫共沉淀和质谱等实验证实白血病耐药相关单抗———5D12在HL-60细胞膜抗原为细胞核因子富含脯氨酸和谷氨酰胺的剪切因子（PSF），经一系列生物学实验确证PSF在HL-60细胞膜的易位表达，在敏感株的膜表达显著高于耐药株的膜表达。流式细胞术检测结果表明PSF的特异性单抗5D12与血液肿瘤多种细胞系的膜结合率为：HL-60（78.56±0.76）%；K562（26.54±4.42）%；Nomalwa（38.10±5.11）%；U937（64.03±7.96）%；Jurkat（29.12±5.58）%；Raji（74.92±3.41）%；CEM（12.18±3.21）%。结论　核蛋白PSF易位表达于多种血液肿瘤细胞膜，对维持肿瘤细胞对化疗药的敏感性有重要作用，是血液肿瘤耐药预测的候选靶点。

PSF/SFPQ relocated on cell membrane in hematologic neoplasia, a potential MDR target of hematologic tumors

Objective To identify muhidrug resistance （MDR） associated cell surface antigen in hematologic neoplasia and to investigate the universality of membrane-relocated expression of this antigen in hematologic neoplasia. Methods The membrane antigen was isolated and precipitated by SDS-PAGE and co-immunoprecipitation （co-IP）, then was identified by mass spectrum （MS）. Specific siRNA was used to interfere with gene expression, laser confocal microsopy was used to validate the results involved in antigen information. FACS was performed to analyse relocated expression of the antigen in hematologic neoplasia. Results Co-IP and MS show that a nuclear factor PSF was the antigen of 5D12, a leukemia-MDR associated McAb, and this antigen could relocate on HL-60 cell membrane. A series of experiences further continued that PSF overexpressed on HL-60 cell membrane compared with HL-60/ADR. The binding percentages of 5D12 to many hematologic tumor cells were observed, HL-60 （78.56＋_0.76） %, K562 （26.54＋4.42） %, Nomalwa （38.10＋5.11） %, U937 （64.03＋7.96） %, Jurkat （29.12＋5.58） %, Raji （74.92＋3.41） %, CEM （12.18＋- 3.21） %. Conclusion Nuclear protein, PSF relocalizes on cell surfaces in hematologic tumor ceils and contributes to cell sensitivity. PSF is a potential target of MDR prediction in hematologic neoplasia.