Xu Yingdong, Deng Na, Wang Xiaoou, Chen Yinghui, Li Guiji, Fan Hua
Department of Hematology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning 110001, P.R. China.
Department of Oncology, The Fourth Affiliated Hospital of China Medical University, Shenyang, Liaoning 110032, P.R. China.
Oncol Lett. 2017 Jul;14(1):965-970. doi: 10.3892/ol.2017.6182. Epub 2017 May 17.
Raf kinase trapping to Golgi (RKTG) is reported to be a tumor suppressor in a number of solid tumors due to its negative modulation of the Ras/Raf/mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (ERK) pathways. However, the role of RKTG in the progression of leukemia remains unknown. In the present study, a human leukemia U937 cell line overexpressing RKTG was established, and the effect of RKTG on proliferation, cell cycle and apoptosis of human leukemia cells was analyzed. The results of the present study demonstrated that exogenous overexpression of RKTG significantly inhibited cell proliferation, which was accompanied by cell cycle arrest. Apoptosis assay and Hoechst staining demonstrated that the percentage of apoptotic cells in RKTG overexpressing cells was markedly increased. Furthermore, western blotting showed that RKTG overexpression significantly increased the level of cleaved caspase 3, B-cell lymphoma 2 (Bcl2)-associated X apoptosis regulator and reduced the level of Bcl-2. In addition, the activation of ERK and phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase 1 signaling pathways in human leukemia cells was also suppressed by RKTG overexpression. In conclusion, the present study demonstrated the tumor-suppressive effect of RKTG on human leukemia cells, which seem to be partially dependent on the suppression of ERK and PI3K/AKT signaling. Overexpression of RKTG may be a potential therapeutic target for the treatment of leukemia.
据报道，Raf激酶捕获到高尔基体（RKTG）由于其对Ras/Raf/丝裂原活化蛋白激酶激酶/细胞外信号调节激酶（ERK）通路的负调控作用，在多种实体瘤中是一种肿瘤抑制因子。然而，RKTG在白血病进展中的作用仍不清楚。在本研究中，建立了过表达RKTG的人白血病U937细胞系，并分析了RKTG对人白血病细胞增殖、细胞周期和凋亡的影响。本研究结果表明，RKTG的外源性过表达显著抑制细胞增殖，并伴有细胞周期阻滞。凋亡检测和Hoechst染色表明，过表达RKTG的细胞中凋亡细胞的百分比明显增加。此外，蛋白质印迹法显示，RKTG过表达显著增加了裂解的半胱天冬酶3、B细胞淋巴瘤2（Bcl2）相关X凋亡调节因子的水平，并降低了Bcl-2的水平。此外，RKTG过表达还抑制了人白血病细胞中ERK和磷酸肌醇3激酶（PI3K）/AKT丝氨酸/苏氨酸激酶1信号通路的激活。总之，本研究证明了RKTG对人白血病细胞具有肿瘤抑制作用，这似乎部分依赖于对ERK和PI3K/AKT信号的抑制。RKTG的过表达可能是治疗白血病的潜在治疗靶点。
