Molecular changes associated with the development of resistance to imatinib in an imatinib-sensitive canine neoplastic mast cell line carrying a KIT c.1523A>T mutation
Molecular changes associated with the development of resistance to imatinib in an imatinib-sensitive canine neoplastic mast cell line carrying a KIT c.1523A>T mutation
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携带 KIT c.1523A>T 突变的伊马替尼敏感犬肿瘤肥大细胞系中与伊马替尼耐药相关的分子变化
DOI：
10.1111/ejh.12526
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Bonkobara M.
中科院分区：
文献类型：
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作者：
Kobayashi M;Kuroki S;Tanaka Y;Moriya Y;Kozutumi Y;Uehara Y;Ono K;Tamura K;Washizu T;Bonkobara M.
虽然伊马替尼对某些肥大细胞增多症患者有治疗活性，但它并不总是治愈的。在这里，使用携带AKITc.1523A和GT；T激活突变的对伊马替尼敏感的犬肿瘤肥大细胞系VI-MC，研究了赋予伊马替尼对肿瘤肥大细胞耐药性的分子机制。通过增加伊马替尼浓度培养VI-MC细胞(1μM抗性，rVI-MC1；10μM抗性，rVI-MC10)，建立了两个伊马替尼耐药亚系。两株亚系均有第二个KIT突变c.2443G>；C，重组试剂盒对1μM不敏感，对10μM伊马替尼敏感。然后利用这些亚系检测伊马替尼对KIT及其下游信号蛋白磷酸化的影响。KIT和ERK在两种亚系中均呈结构性磷酸化，10μM伊马替尼可抑制Kit和ERK的磷酸化。然而，在rvi-MC10细胞中，KIT而不是ERK的磷酸化受到抑制。Src家族激酶(SFK)抑制剂达沙替尼也不能抑制rvi-MC10细胞中ERK的磷酸化。KIT中的第二个突变可能在肿瘤肥大细胞对伊马替尼的耐药性中发挥重要作用。此外，当肿瘤细胞暴露于较高浓度的伊马替尼时，不依赖于KIT/SFK的ERK激活可能参与了伊马替尼耐药。
Although imatinib has therapeutic activity for certain subsets of patients with mastocytosis, it is not always curative. Here, molecular mechanisms that confer imatinib resistance to neoplastic mast cells were investigated using an imatinib‐sensitive canine neoplastic mast cell line VI‐MC carrying aKITc.1523A>T activating mutation. Two imatinib‐resistant sublines were established by culturing VI‐MC cells in increasing concentrations of imatinib (1μM resistant, rVI‐MC1; 10μM resistant, rVI‐MC10). Both sublines had a secondKITmutation c.2443G>C. Recombinant KIT with the second mutation was insensitive to 1μM but sensitive to 10μM imatinib. The effect of imatinib on the phosphorylation of KIT and its downstream signalling proteins was then examined using these sublines. KIT and ERK were constitutively phosphorylated in both sublines, and their phosphorylation was suppressed by 10μM imatinib in rVI‐MC1 cells. However, KIT but not ERK phosphorylation was suppressed in rVI‐MC10 cells. The phosphorylation of ERK in rVI‐MC10 cells was also not diminished by the Src family kinase (SFK) inhibitor dasatinib. This second mutation inKITmay play an important role in imatinib resistance in neoplastic mast cells. Furthermore, KIT/SFK‐independent activation of ERK would be involved in imatinib resistance when the neoplastic cells are exposed to higher concentrations of imatinib.