PI3K/Akt途径在朊蛋白介导胃癌耐药中的作用研究  

Effects of PI3K/Akt signaling pathway on PrPc induced drug resistance in gastric cancer

作　　者：葛伏林[1] 吴本俨[1] 张燕齐[2] 韩霜[2] 丁杰[2] 

机构地区：[1]解放军总医院南楼消化内科,北京100853 [2]第四军医大学西京医院全军消化病研究所肿瘤生物学国家重点实验室,陕西西安710032

出　　处：《现代肿瘤医学》2009年第11期2051-2054,共4页Journal of Modern Oncology

基　　金：国家自然科学基金资助项目(编号:30572134)

摘　　要：目的:探讨PI3K/Akt途径在朊蛋白(PrPc)介导胃癌耐药中的作用。方法:脂质体基因转染法建立高表达PrPc的胃癌细胞亚系。Western印迹检测转染细胞中Akt蛋白的表达。噻唑蓝(MTT)比色法测定单独或联用PI3K抑制剂LY294002时转染细胞对化疗药物的敏感性。流式细胞仪检测单独或联用LY294002时转染细胞内阿霉素蓄积和潴留。结果:将PrPc正义载体pcDNA-PrP转入SGC7901,成功建立PrPc高表达胃癌细胞亚系并命名为PS;空载体转染细胞命名为BS。Western-Blot显示磷酸化Akt在PS中的表达较BS及SGC7901增高,而三者的总Akt则无差别。未经LY294002处理时,在阿霉素或长春新碱的作用下,PS的存活率分别为91.4%±3.4%和89.4%±3.8%,较BS(79.2%±4.3%和75.9%±2.1%)明显增高(均),PS细胞内阿霉素蓄积量和潴留量分别为4.4±0.3和4.2±0.4,明显低于BS(8.2±0.5和8.0±0.3)(均);当联合LY294002处理后,PS在两种药物作用下的存活率均随着LY294002浓度的增加逐渐降低,并均在LY294002为30μmol/L时接近BS(均),PS细胞内阿霉素蓄积量和潴留量逐渐增高,并均在LY294002为30μmol/L时接近BS(均)。结论:PrPc介导的胃癌耐药与PI3K/Akt途径活性密切相关,抑制PI3K/Akt途径活性可逆转PrPc介导的胃癌耐药。Objective：To investigate the effects of PI3K/Akt signaling pathway on PrPc induced drug resistance in gastric cancer. Methods： PrPc overexpression gastric cancer cell lines were established by pcDNA - PrP transfection using Lipofectamine 2000 . The expressions of total Akt and phosphorylated Akt were detected by Western blot. MTT assay was applied to evaluate in vitro effects of chemotherapeutic agent with or without the inhibitor of PI3K - LY294002. The accumulation and retention of adriamycin in these tranfectants were determined by flow cytometric analysis. Results：Stable cell lines of PrPc overexpressed SGC7901 （named PS）and empty control （named BS） were acquired after 1 month G418 selection and were confirmed by Western blot. The phosphorylated form of Akt proteins was highly expressed in PS compared to BS and SGC7901, however,the total levels of Akt showed no difference among the PS and its controls. In the absence of LY294002, relatively survival rates of PS in ADR or VCR （ ADR 91.4%± 3.4%, VCR89.4% ± 3.8% ） were both significantly higher than those of BS （79.2% ± 4.3% ,75.9% ±2.1% ） （ both ）. Adriamycin accumulation and retention value of PS （4.4 ± 0.3,4.2 ± 0.4 ） were both significantly lower than those of BS （ 8.2 ±0.5,8.0±0.3 ） （ both ）. However, when treated with LY294002, the survival rates of PS in ADR or VCR were both decreased with the increasing concentrations of LY294002. ADR accumulation and retention of PS were both increased with the increasing concentration of LY294002. The highest concentration of LY294002 （30μmol/L） resulted in the survival rate reduction to the levels similar to those of BS（both ）and ADR accumulation and retention of PS increasing to the levels similar to those of BS （ both ）. Conclusion： PrPc induced cell drug resistance is correlated with activation of PI3K/AKT pathway. Inhibition of PI3K/AKT signaling pathway by LY2940002 leads to the inhibition of PrPc induced cell drug resistance in gastric cancer cells.

关 键 词：朊蛋白 PI3K/AKT 耐药 胃癌 

分 类 号：R735.2[医药卫生—肿瘤]