mTOR信号通路对人类鼻咽癌细胞增殖的调控作用

The role of mTOR signaling in proliferation of human nasopharyngeal carcinoma cells

目的:探讨mTOR信号通路在鼻咽癌细胞中是否激活以及mTOR抑制剂雷帕霉素对细胞增殖的调控作用。方法:利用原代培养的人类鼻咽癌细胞,采用Western blot法和免疫荧光细胞化学法检测人类鼻咽癌细胞中mTOR信号通路活化情况;采用Western blot方法检测不同浓度雷帕霉素作用24 h后细胞中S6、pS6、mTOR、pmTOR蛋白的表达量;同时用CCK8检测雷帕霉素作用24 h后细胞的存活情况。结果:West-ern blot法检测结果显示S6、pS6、mTOR、pmTOR四种蛋白在原代培养的人类鼻咽癌细胞中呈阳性表达。免疫荧光进一步证实mTOR和pmTOR两种蛋白主要表达于鼻咽癌细胞浆中。当雷帕霉素浓度为0～100nmol/L时,随着药物浓度增加,四种蛋白的表达量逐渐下降,相应的细胞存活率也逐渐下降。但当雷帕霉素浓度超过100 nmol/L时,药物浓度增加对鼻咽癌细胞增殖抑制的影响无明显变化。雷帕霉素浓度为0和1 000 nmol/L时,鼻咽癌细胞的存活率存在较大差异。结论:mTOR信号在人类原发鼻咽癌细胞中呈激活状态,对这些细胞增殖起重要的调控作用。

Objective： To explore whether mTOR signaling was activated in nasopharyngeal carcinoma （NPC） cells, and whether mTOR inhibitor, rapamycin, inhibits the proliferation of NPC cells. Methods： The NPC cells were isolated from patients with NPC and cultured in vitro. Western blot and immunocytochemistry were used to detect the activation level of mTOR signaling. In addition, NPC cells were treated with rapamycin for 24 hours and then Western blot was used to evaluate the activation of mTOR signaling and CCK8 were used to detect the proliferative rate of NPC cells. Results： $6, pS6, mTOR and pmTOR were expressed in NPC cells by western blot. Immunostaining showed that mTOR and pmTOR were mainly expressed in the cytoplasma of NPC cells. The expression levels of $6, pS6, mTOR and pmTOR were gradually decreased with increasing of the concentra- tion of rapamycin from 0 to 100 nmol/L. Similarly, the survival rate of NPC cells was decreased gradually. No difference was observed when the concentration of rapamycin was over 100 nmol/L. A significant difference of survival rate was found after treatment with rapamycin 1 000 nmol/L, compared with control group. Conclusion： mTOR signaling is activated and plays a critical role in the proliferation of human primary NPC cells, which open a new avenue for NPC treatment.