Li Junan, Zhu Jiuxiang, Melvin W Scott, Bekaii-Saab Tanios S, Chen Ching-Shih, Muscarella Peter
Departments of Surgery and Internal Medicine, College of Medicine, The Ohio State University, 410 West 10th Avenue, Columbus, OH 43210, USA.
J Gastrointest Surg. 2006 Feb;10(2):207-14. doi: 10.1016/j.gassur.2005.07.025.
Deregulation of the phosphatidylinositol 3-kinase (PI-3K)/PDK-l/Akt signaling cascade is associated with pancreatic cancer tumor invasion, angiogenesis, and tumor progression. As such, it has been postulated that PDK-1/Akt signaling inhibitors may hold promise as novel therapeutic agents for pancreatic cancer. Disadvantages of currently available Akt inhibitors include tumor resistance, poor specificity, potential toxicity, and poor bioavailability. Previous studies have demonstrated that OSU-03012, a celecoxib derivative, specifically inhibits PDK-1 mediated phosphorylation of Akt with IC(50) values in the low muM range. Human pancreatic cancer cell lines AsPC-1, BxPC-3, Mia-PaCa 2, and PANC-1 were cultured in media containing varying concentrations of OSU-03012, 5-fluorouracil (5-FU), and gemcitabine, and changes in Akt phosphorylation and cell viability were evaluated using western blotting and a 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) assay, respectively. Treatment with OSU-03012 resulted in decreased PDK-1-mediated Akt phosphorylation and cell growth inhibition for all cell lines with IC(50) values ranging between 1.0 and 2.5 muM. Resistance to 5-FU and gemcitabine was observed in cell lines AsPC-1 and BxPC-3. Further analyses indicate that OSU-03012 induces both proapoptotic and antiproliferative effects in these cells. Taken together, these data suggest that OSU-03012 has potential value as a novel therapy for pancreatic cancer.
磷脂酰肌醇3激酶(PI-3K)/磷酸脱氢酶-1(PDK-1)/蛋白激酶B(Akt)信号级联反应失调与胰腺癌的肿瘤侵袭、血管生成及肿瘤进展相关。因此,有人推测PDK-1/Akt信号抑制剂有望成为治疗胰腺癌的新型治疗药物。目前可用的Akt抑制剂存在肿瘤耐药性、特异性差、潜在毒性及生物利用度低等缺点。先前的研究表明,塞来昔布衍生物OSU-03012能特异性抑制PDK-1介导的Akt磷酸化,其半数抑制浓度(IC50)值在低 microM范围内。将人胰腺癌细胞系AsPC-1、BxPC-3、Mia-PaCa 2和PANC-1培养于含有不同浓度OSU-03012、5-氟尿嘧啶(5-FU)和吉西他滨的培养基中,分别使用蛋白质免疫印迹法和3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)法评估Akt磷酸化变化和细胞活力。用OSU-03012处理后,所有细胞系的PDK-1介导的Akt磷酸化均降低,细胞生长受到抑制,IC50值在1.0至2.5 microM之间。在细胞系AsPC-1和BxPC-3中观察到对5-FU和吉西他滨的耐药性。进一步分析表明,OSU-03012在这些细胞中诱导了促凋亡和抗增殖作用。综上所述,这些数据表明OSU-03012作为胰腺癌的新型治疗方法具有潜在价值。