中文摘要：

目的研究门冬酰胺酶（asparaginase,AN）对小细胞肺癌H1688和H446细胞的抗癌作用,探讨自噬在AN抗癌过程中的功能。方法采用MTT法及台盼蓝染色法检测AN单独或联用自噬抑制剂氯喹（chloroquine,CQ）对H1688和H446细胞的生长抑制作用;免疫荧光法观察自噬标记物LC3表达,示踪自噬体形成;Western blot检测自噬相关蛋白LC3及Akt/m TOR信号通路的表达。结果 AN呈浓度依赖性抑制H1688和H446细胞增殖并促进其死亡（P〈0.05）;AN处理组可以显著增加H1688和H446细胞自噬小体数量并诱导LC3-Ⅱ表达;自噬抑制剂CQ提高AN对H1688和H446细胞杀伤作用（P〈0.05）;AN作用H1688细胞后p-Akt、p-m TOR、p-70S6K蛋白表达降低。结论 AN对小细胞肺癌H1688和H446细胞具有抑制作用并诱导细胞保护性自噬,阻断自噬可以增强AN对小细胞肺癌H1688和H446细胞的抗癌疗效。

英文摘要：

Objective To study the anticancer effect of asparaginase（ AN） and the role of autophagy in the anticancer process of AN in small cell lung cancer H1688 and H446 cells. Methods MTT assay and trypan blue exclusion assay were applied to assess the viability of H1688 and H446 cells after treatment with AN alone or in combined with autophagy inhibitor chloroquine（ CQ）. Then the formation of autophagy marker LC3 was observed by immunofluorescence assay. Western blotting was used to determine the expression of LC3 and Akt/m TOR signal pathway proteins. Results AN inhibited cell growth in a dose-dependent manner（ P〈0. 05）,and significantly increased the quantity of autophagy bodies and the expression of LC3-II in H1688 and H446 cells. CQ promoted the inhibitory effect of AN to H1688 and H446 cells（ P〈0. 05）. AN also suppressed the expression of p-Akt,p-m TOR and p-70S6 K in H1688 cells. Conclusion AN inhibits the growth of H1688 and H446 cells,and inhibition of cytoprotective autophagy enhances the anticancer effect of AN.