Cellular effects of imatinib on medullary thyroid cancer cells, harboring multiple endocrine neoplasia Type 2A and 2B associated RET mutations
Cellular effects of imatinib on medullary thyroid cancer cells, harboring multiple endocrine neoplasia Type 2A and 2B associated RET mutations
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DOI：
10.1016/j.surg.2005.10.019
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发表时间：
2006-06-01
期刊：
影响因子：
3.8
通讯作者：
Hofstra, R. A. W.
中科院分区：
文献类型：
--
作者：
de Groot, J. W. B.;Menacho, I. Plaza;Hofstra, R. A. W.
背景RET基因（编码酪氨酸激酶受体）的激活突变通常会导致甲状腺髓样癌（MTC）。手术切除是唯一的治愈性治疗;没有有效的系统治疗。我们评估了伊马替尼，酪氨酸激酶抑制剂目前用于治疗慢性髓性白血病和胃肠道间质瘤，作为一种潜在的药物，全身治疗MTC，在2 MTC衍生细胞系表达多发性内分泌肿瘤相关的突变RET receptor. Methods。我们确定RET表达和Y1062磷酸化蛋白质印迹分析和定量聚合酶链反应。我们通过3-[4，5-dimethylthiazol-2 yl]-2，5-dipheryltetrazolium bromide检测来确定对细胞增殖的影响，并使用荧光激活细胞分选仪分析结合annexin V/propdium zodide染色来研究伊马替尼诱导的细胞周期阻滞、凋亡和细胞死亡。暴露1.5小时后，伊马替尼以剂量依赖性方式抑制RET Y1062磷酸化。16小时后，RET Y1062磷酸化和蛋白表达水平均受到影响。在暴露于抑制浓度为50%水平（23 +/- 2 μ mol/L和25 +/- 4 μ mol/L）的伊马替尼后，观察到两种细胞系的细胞增殖呈剂量依赖性降低。与慢性粒细胞性白血病和胃肠道间质瘤相比，这些值较高。我们还发现伊马替尼可诱导细胞周期阻滞、凋亡性和非凋亡性细胞死亡。伊马替尼在体外以剂量依赖性方式抑制RET介导的MTC细胞生长，影响RET蛋白水平。然而，体外抑制RET所需的伊马替尼浓度使得无法得出结论，伊马替尼单药治疗将是MTC全身治疗的良好选择。
Background. Activating mutations in the RET gene, which encodes a tyrosine kinase receptor, often cause medullary thyroid carcinoma (MTC). Surgical resection is the only curative treatment; no effective systemic treatment is available. We evaluated imatinib, a tyrosine kinase inhibitor currently used to treat chronic myelogenous leukemia and gastrointestinal stromal tumors, as a potential drug for systemic treatment of MTC, in 2 MTC-derived cell lines expressing multiple endocrine neoplasia-associated mutant RET receptors.Methods. We determined RET expression and Y1062 phosphorylation using Western blot analysis and quantitative polymerase chain reaction. We determined the effects on cell proleration by a 3-[4,5-dimethylthiazol-2yl]-2,5-dipheryltetrazolium bromide assay, and we used fluorescence-activated cell sorter analysis with annexin V/propdium zodide staining to study imatinib-induced cell-cycle arrest, apoptosis, and cell death.Results. Imatinib inhibited RET Y1062 phosphayylation in a dose-dependent manner after 1.5 hours of exposure. After 16 hours both RET Y1062 phosphorylation and protein expression levels were affected. Dose-dependent decreases in cell Proliferation of both cell lines after exposure to imatinib with inhibitory concentration of 50% levels of 23 +/- 2 mu mol/L and 25 +/- 4 mu mol/L were seen. These values are high, compared with those for chronic myelogenous leukemia and gastrointestinal stromal tumors. We further could show that imatinib induced cell-cycle arrest, and opoptotic and nonapoptotic cell death.Conclusions. Imatinib inhibits RET-mediated MTC cell growth affecting RET protein levels in vitro in a dose-dependent manner. The concentration of imatinib necessardfy to inhibit RET in vitro, however, makes it impossible to conclude that imatinib monotherapy will be a good option for systemic therapy of MTC.