中文摘要：

目的：通过人工诱导建立肿瘤坏死因子相关凋亡诱导配体（TRAIL）获得性耐药的肺癌细胞系,氯化锂联合rhTRAIL作用细胞,以期了解氯化锂增敏TRAIL的现象及机制。方法：通过低剂量rhTRAIL诱导人肺大细胞癌细胞系H460,建立TRAIL耐药细胞株H460R并鉴定,应用MTT和流式细胞术分析氯化锂和rhTRAIL联合给药后亲本株与耐药株细胞增殖和凋亡差异,应用RT-PCR和Western blot检测死亡受体表达。结果：rhTRAIL处理亲本株H460和耐药株H460R后细胞存活率存在显著差异（P〈0.01）,IC50分别为59.2ng/ml和294.8ng/ml。60ng/ml rhTRAIL处理耐药株及亲本株后平均细胞凋亡比例存在显著差异（10.5%vs 19.4%,P〈0.01）,耐药株表现出显著的TRAIL耐受现象。但联合20mmol/L氯化锂后,MTT及流式细胞术检测耐药株细胞增殖及凋亡发现H460R对rhTRAIL的敏感性显著增加。进一步研究发现死亡受体DR4和DR5的mRNA及蛋白水平升高,这可能是药物增敏的机制之一。结论：氯化锂能够增加获得性耐药细胞系H460R对TRAIL的敏感性,死亡受体表达增加是可能的增敏机制之一。

英文摘要：

Objective：To evaluate whether LiCl increases drug sensitivity of TRAIL by establishing an acquired TRAIL-resistant human lung cancer cell subline.Methods：Human lung large cell carcinoma cell line H460 was treated by gradually increasing concentration recombinant human TRAIL（rhTRAIL）to establish acquired TRAIL-resistant cell subline which was identified by MTT and flow cytometry.Same methods were used to analyze the difference of cell survival rate and apoptosis rate between rhTRAIL and addition of LiCl.RT-PCR and Western blot were used to detect the expression of death receptor 4and 5.Results：The difference of cell survival rate between parental and drug-resistant cell line was significant（P0.01）with IC50 value of 59.2ng/ml and294.8ng/ml,respectively.Apoptosis rate differences were also observed.An acquired TRAILresistant cell line（H460R）was established.This feature,however,can be reversed by LiCl.Weobserved combination of LiCl and rhTRAIL resulted in a significant increase of apoptosis rate of H460 R.Further research revealed that expression of death receptor 4and 5were upregulated and this may contribute to the synergistic effect of LiCl and rhTRAIL.Conclusion：LiCl increased drug sensitivity of TRAIL on acquired TRAIL-resistant cell line H460 Rand overexpression of death receptor 4and 5was one possible contributor.