Martins Ana S, Mackintosh Carlos, Martín David Herrero, Campos Maria, Hernández Teresa, Ordóñez Jose-Luis, de Alava Enrique
Laboratory 20-Molecular Pathology, Centro de Investigación del Cáncer Instituto de Biología Molecular y Celular del Cáncer, Universidad de Salamanca-Consejo Superior de Investigaciones Cientificas, Salamanca, Spain.
Clin Cancer Res. 2006 Jun 1;12(11 Pt 1):3532-40. doi: 10.1158/1078-0432.CCR-05-1778.
Ewing tumor cell survival and proliferation depends on several autocrine loops. Targeting these loops is a promising therapeutic approach. We recently showed the cytostatic role of imatinib, an inhibitor of the SCF-KIT loop, on Ewing tumor cells, and in this study, we intend to analyze the inhibition of the insulin-like growth factor I receptor (IGF1R) loop.
We analyzed IGF1R blockade by ADW742, a small molecule specific for this receptor, alone and in combination with imatinib, vincristine, and doxorubicin on Ewing tumor cell lines. We studied the effect on proliferation, apoptosis, cell cycle, pathway phosphorylation, soft-agar growth, motility, and vascular endothelial growth factor expression levels.
Treatment with ADW742 induced down-regulation of IGF1R/AKT/mammalian target of rapamycin (mTOR) phosphorylation, which was deeper in cell lines having higher IGF1R activation levels. Treatment also induced dose-dependent inhibition of cell proliferation (IC50 = 0.55-1.4 micromol/L), inducing a G1 phase blockage and apoptosis. Addition of imatinib to ADW742 synergistically augmented these effects and was especially effective in inhibiting AKT/mTOR phosphorylation and reducing vascular endothelial growth factor expression in cell lines having high IGF1R activation levels. Combination with usual chemotherapeutic agents vincristine and doxorubicin showed synergistic interactions.
Inhibition of Ewing tumor cell proliferation by ADW742 is mediated through blockade of IGF1R signaling. Combination of ADW742 with imatinib, vincristine, and doxorubicin induces a significant reduction of tumor cell growth, mainly by the increase in apoptosis with a pattern depending on IGF1R activation levels. This study supports a potential role for ADW742 in the treatment of Ewing tumor and AKT/mTOR as a possible surrogate marker of response to therapy.
尤因肿瘤细胞的存活和增殖依赖于多个自分泌环路。靶向这些环路是一种很有前景的治疗方法。我们最近展示了伊马替尼（一种SCF-KIT环路抑制剂）对尤因肿瘤细胞的细胞生长抑制作用，在本研究中，我们打算分析对胰岛素样生长因子I受体（IGF1R）环路的抑制作用。
我们分析了ADW742（一种针对该受体的小分子）单独以及与伊马替尼、长春新碱和阿霉素联合使用时对尤因肿瘤细胞系中IGF1R的阻断作用。我们研究了其对增殖、凋亡、细胞周期、信号通路磷酸化、软琼脂生长、迁移以及血管内皮生长因子表达水平的影响。
用ADW742处理可诱导IGF1R/AKT/雷帕霉素哺乳动物靶蛋白（mTOR）磷酸化水平下调，在IGF1R激活水平较高的细胞系中这种下调更明显。处理还诱导了剂量依赖性的细胞增殖抑制（IC50 = 0.55 - 1.4微摩尔/升），导致G1期阻滞和凋亡。在ADW742中添加伊马替尼可协同增强这些作用，并且在抑制IGF1R激活水平较高的细胞系中的AKT/mTOR磷酸化以及降低血管内皮生长因子表达方面特别有效。与常用化疗药物长春新碱和阿霉素联合使用显示出协同相互作用。
ADW742对尤因肿瘤细胞增殖的抑制作用是通过阻断IGF1R信号传导介导的。ADW742与伊马替尼、长春新碱和阿霉素联合使用可显著降低肿瘤细胞生长，主要是通过增加凋亡，其模式取决于IGF1R激活水平。本研究支持ADW742在尤因肿瘤治疗中的潜在作用以及AKT/mTOR作为治疗反应可能替代标志物的作用。
