N糖基取代的沙利度胺新衍生物对人鼻咽癌细胞耐药逆转作用研究

Reversal Effect of A Novel N-sugar Substituted Thalidomide Analogue on Multidrug Resistant Human Nasopharyngeal Carcinoma Cells

肿瘤细胞对化疗药物产生耐药性是化疗失败的主要原因,发展新型的耐药逆转剂是克服肿瘤细胞耐药的重要策略之一.首先采用浓度梯度递增法诱导建立对紫杉醇(Taxol,TAX)耐药的人鼻咽癌(KB)细胞耐药株(KB/TAX),再通过细胞毒性检测、流式细胞仪分析、Western blotting和RT-PCR等方法鉴定耐药细胞株的特征,研究沙利度胺新衍生物邻苯二甲酰亚氨基葡萄糖苷(STA-35)对该耐药细胞株的耐药逆转作用与可能的分子机制.实验结果表明,KB/TAX细胞对多种化疗药物产生抗性,对TAX的耐药指数达73.1.与亲本细胞相比,耐药细胞内P-糖蛋白(P-glucoprotein,P-gp)的功能与表达均增强、多药耐药基因mdr1表达量增加.N糖基取代的沙利度胺新衍生物STA-35可显著抑制KB/TAX细胞及其亲本KB生长,与TAX联合应用时可降低KB/TAX细胞对TAX的耐药指数.此外,STA-35(5～20μmol/L)可浓度依赖地提高KB/TAX细胞中罗丹明123的蓄积量、抑制P-gp的表达,但对mdr1基因表达无明显作用.研究表明,N糖基取代的沙利度胺新衍生物STA-35能够逆转KB/TAX细胞对TAX的耐药性,可能的分子机制与其抑制P-gp功能和蛋白质表达相关.

One major problem to successful treatment of cancer is the development of resistance by tumor cells to multiple chemotherapeutic drugs, a phenomenon named multidrug resistance （MDR）. Searching for the novel chemotherapeutical agents is one of the important strategies for overcoming MDR. By using a cytotoxicity assay, flow cytometry analysis, Western-blotting and RT-PCR, a drug （Taxol, TAX） resistant human nasopharyngeal carcinoma KB cell line （KB/TAX） was established by addition of the drug to the cell cultures gradually, then a novel N-sugar substituted thalidomide analogue （STA-35） was investigated for its reversal effect on MDR of KB/TAX cells and possible mechanism. The results showed that KB/TAX cells were resistant to several chemotherapeutical agents, and the relative resistance to TAX was 73.1. Compared with parental KB cells, the function and protein expression of P-glycoprotein （P-gp）, as well as mdrl gene in the KB/TAX cells were remarkable reduced. Moreover, both KB and KB/TAX cells were sensitive to STA-35, the relative resistance to TAX on KB/TAX cells was decreased by the addition of STA-35. Furthermore, STA-35 （5 -20 μmol/L）was capable to reduced the activity of P-gp by increasing the accumulation of rhodamine 123, decreasing P-gp expression in KB/TAX cells in a dose dependent manner, but had no effect on the mdrl gene expression. These results suggest a potential action of STA-35 as MDR reversing agent, and one of the possible mechanisms could be the suppression of P-gp function and protein expression.