Akt 与核因子 κB 结合，在胃癌细胞的化疗耐药中发挥重要作用。

Akt associates with nuclear factor kappaB and plays an important role in chemoresistance of gastric cancer cells.

机构信息

Department of Gastroenterology, Sir Run Run Shaw Affiliated Hospital of Zhejiang University, Hangzhou 310016, Zhejiang Province, PR China.

出版信息

Oncol Rep. 2010 Jul;24(1):113-9. doi: 10.3892/or_00000835.

DOI:10.3892/or_00000835

PMID:20514451

Abstract

The ubiquitously expressed serine-threonine kinase Akt and the transcription factor NF-kappaB both are involved in cell proliferation and apoptosis. Furthermore, the activation of Akt or NF-kappaB has been suggested to associate with chemo-resistance of human tumors. The exact mechanism and interreaction of Akt and NF-kappaB pathway on chemoresistance in gastric cancer is still unknown. We explored the function of Akt and NF-kappaB pathway on chemoresistance in human gastric cancer cells. MTT method was used to analyze the influence of chemotherapeutics and the combined use of wortmannin or MG-132 on the growth of SGC-7901 cells. Apoptosis of SGC-7901 was detected by TUNEL and Annexin V/PI methods. The protein level of NF-kappaB was analyzed by immunocytochemical staining. EMSA was used to confirm the increased nuclear translocation of RelA. The protein level of p-Akt and p-IkappaBalpha were analyzed by Western blotting. Etoposide and doxorubicin suppressed the growth of SGC-7901 time and dose-dependently. Combined use of wortmannin or MG-132 can suppress growth further. Chemotherapeutics induced apoptosis of SGC-7901 and activated Akt and NF-kappaB, combined use of wortmannin or MG-132 induced apoptosis further and attenuated the activation of NF-kappaB. The combined use of wortmannin attenuated the activation of Akt, but combined use of MG-132 did not attenuate the activation of Akt. The activation of NF-kappaB is a branch mechanism of Akt anti-apoptosis effects. The chemotherapeutics induced apoptosis and induced the activation of Akt and NF-kappaB in SGC-7901 cell, suppression the activation of Akt or NF-kappaB can increase the effects of chemotherapeutics. NF-kappaB is a downstream target of Akt.

摘要

普遍表达的丝氨酸-苏氨酸激酶 Akt 和转录因子 NF-κB 都参与细胞增殖和凋亡。此外，Akt 或 NF-κB 的激活已被认为与人类肿瘤的化疗耐药性有关。Akt 和 NF-κB 通路在胃癌化疗耐药中的确切机制和相互作用尚不清楚。我们探讨了 Akt 和 NF-κB 通路对人胃癌细胞化疗耐药性的作用。MTT 法分析化疗药物及渥曼青霉素或 MG-132 联合应用对 SGC-7901 细胞生长的影响。TUNEL 和 Annexin V/PI 法检测 SGC-7901 细胞的凋亡。免疫细胞化学染色分析 NF-κB 蛋白水平。EMSA 法证实 RelA 核转位增加。Western blot 法分析 p-Akt 和 p-IκBα 蛋白水平。依托泊苷和阿霉素时间和剂量依赖性地抑制 SGC-7901 的生长。渥曼青霉素或 MG-132 的联合应用可进一步抑制生长。化疗药物诱导 SGC-7901 细胞凋亡并激活 Akt 和 NF-κB，渥曼青霉素或 MG-132 的联合应用进一步诱导凋亡并减弱 NF-κB 的激活。渥曼青霉素的联合应用减弱了 Akt 的激活，但 MG-132 的联合应用并没有减弱 Akt 的激活。NF-κB 的激活是 Akt 抗凋亡作用的分支机制。化疗药物诱导 SGC-7901 细胞凋亡并诱导 Akt 和 NF-κB 激活，抑制 Akt 或 NF-κB 的激活可增强化疗药物的作用。NF-κB 是 Akt 的下游靶标。