Hématopoïèse Leucémique et Cible Thérapeutique, Inserm U1035, Université Victor Ségalen, Bordeaux, France.
Blood. 2011 Aug 25;118(8):2211-21. doi: 10.1182/blood-2010-10-313692. Epub 2011 Jul 5.
In this study, we have addressed how Lyn kinase signaling mediates nilotinib-resistance by quantitative phospho-proteomics using Stable Isotope Labeling with Amino acid in Cell culture. We have found an increased tyrosine phosphorylation of 2 additional tyrosine kinases in nilotinib-resistant cells: the spleen tyrosine kinase Syk and the UFO family receptor tyrosine kinase Axl. This increased tyrosine phosphorylation involved an interaction of these tyrosine kinases with Lyn. Inhibition of Syk by the inhibitors R406 or BAY 61-3606 or by RNA interference restored the capacity of nilotinib to inhibit cell proliferation. Conversely, coexpression of Lyn and Syk were required to fully induce resistance to nilotinib in drug-sensitive cells. Surprisingly, the knockdown of Syk also strongly decreased tyrosine phosphorylation of Lyn and Axl, thus uncovering interplay between Syk and Lyn. We have shown the involvement of the adaptor protein CDCP-1 in resistance to nilotinib. Interestingly, the expression of Axl and CDCP1 were found increased both in a nilotinib-resistant cell line and in nilotinib-resistant CML patients. We conclude that an oncogenic signaling mediated by Lyn and Syk can bypass the need of Bcr-Abl in CML cells. Thus, targeting these kinases may be of therapeutic value to override imatinib or nilotinib resistance in CML.
在这项研究中，我们使用稳定同位素标记的氨基酸在细胞培养中进行定量磷酸蛋白质组学研究，探讨了 Lyn 激酶信号转导如何介导尼洛替尼耐药。我们发现尼洛替尼耐药细胞中增加了另外 2 个酪氨酸激酶的酪氨酸磷酸化：脾酪氨酸激酶 Syk 和 UFO 家族受体酪氨酸激酶 Axl。这种增加的酪氨酸磷酸化涉及这些酪氨酸激酶与 Lyn 的相互作用。Syk 的抑制剂 R406、BAY 61-3606 或 RNA 干扰抑制可恢复尼洛替尼抑制细胞增殖的能力。相反，在敏感药物细胞中，共表达 Lyn 和 Syk 是完全诱导对尼洛替尼耐药所必需的。令人惊讶的是，Syk 的敲低也强烈降低了 Lyn 和 Axl 的酪氨酸磷酸化，从而揭示了 Syk 和 Lyn 之间的相互作用。我们已经证明了衔接蛋白 CDCP-1 在尼洛替尼耐药中的作用。有趣的是，在尼洛替尼耐药细胞系和尼洛替尼耐药 CML 患者中均发现 Axl 和 CDCP1 的表达增加。我们得出结论，由 Lyn 和 Syk 介导的致癌信号可以绕过 CML 细胞中 Bcr-Abl 的需要。因此，靶向这些激酶可能具有治疗价值，可以克服 CML 中伊马替尼或尼洛替尼的耐药性。
