Department of Gastroenterology, Sir Run Run Shaw Affiliated Hospital of Zhejiang University, Hangzhou 310016, Zhejiang Province, PR China.
Oncol Rep. 2010 Jul;24(1):113-9. doi: 10.3892/or_00000835.
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.
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。
