中文摘要：

淋巴细胞特异性蛋白-1（LSP1）在部分多发性骨髓瘤中表达升高,但其在肿瘤中的作用仍知之甚少.研究了LSP1在多发性骨髓瘤中抗新型抗肿瘤药物万珂（Bortezomib）诱导细胞凋亡的作用及机制.筛选LSP1高表达和低表达的多发性骨髓瘤细胞IM9和KAS6作为实验模型.应用RNA干扰基因沉默IM9细胞中的LSP1,或在KAS6细胞中转染LSP1表达质粒,用Bortezomib等化疗药物处理细胞后,PI/Annexin V染色并用流式细胞仪检测和分析细胞凋亡率.同时RT-PCR方法检测和分析被LSP1所影响的重要细胞凋亡相关基因的变化.结果发现,LSP1在多发性骨髓瘤细胞IM9和KAS6中差异性表达高和低,与Bortezomib诱导的细胞凋亡效率密切相关.利用RNA干扰敲低IM9细胞中LSP1,可显著增强IM9对Bortezomib的敏感性,同时在KAS6中转染LSP1表达质粒,可降低Bortezomib诱导的细胞凋亡.对部分重要凋亡基因的RT-PCR检测发现,LSP1可诱导BCL-xl基因表达,同时抑制p53表达.因此,发现LSP1可通过调节凋亡基因的表达促进肿瘤的抗药性.

英文摘要：

To investigate the roles of anti-apoptosis by leukocyte-specific protein 1（LSP1） in Multiple Myeloma cells（MM）,RT-PCR and immunoblotting were used to assess the gene expression in MM cell lines,IM9 and KAS6.Plasmids containing either sh-RNA targeting LSP1 or full-length cDNA coding for human LSP1 were constructed and transfected into IM9 and KAS6 cells,respectively.Cell apoptosis rate induced by Bortezomib was measured by PI/Annexin V staining and FACS assay.The results shows that LSP1 is highly expressed in IM9 cells but undetectable in KAS6 cells and that is closely correlated with their abilities of anti Bortezomib-induced apoptosis.Knockdown LSP1 in IM9 cell leads to significant reduction of anti Bortezomib-induced apoptosis compared with its parent control cells.By contrast,overexpression of LSP1 in KAS6 cells remarkably increases its anti-Bortezomib ability compared with control KAS6 cells.RT-PCR shows that p53 is suppressed and Bcl-xL is up-regulated by LSP1 in MM cells.In conclusion,LSP1 inhibites Bortezomib-induced apoptosis in multiple myelomas by suppressing multiple pro-apoptosis genes.