Caenepeel Sean, Cooke Keegan, Wadsworth Sarah, Huang Guo, Robert Lidia, Moreno Blanca Homet, Parisi Giulia, Cajulis Elaina, Kendall Richard, Beltran Pedro, Ribas Antoni, Coxon Angela, Hughes Paul E
Department of Oncology Research, Amgen, Inc., Thousand Oaks, CA, USA.
Department of Medicine, Division of Hematology-Oncology, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, CA, USA.
Oncotarget. 2017 Mar 14;8(11):17795-17809. doi: 10.18632/oncotarget.14855.
Therapeutic resistance is a major obstacle to achieving durable clinical responses with targeted therapies, highlighting a need to elucidate the underlying mechanisms responsible for resistance and identify strategies to overcome this challenge. An emerging body of data implicates the tyrosine kinase MET in mediating resistance to BRAF inhibitors in BRAFV600E mutant melanoma. In this study we observed a dominant role for the HGF/MET axis in mediating resistance to BRAF and MEK inhibitors in models of BRAFV600E and NRAS mutant melanoma. In addition, we showed that MAPK pathway inhibition induced rapid increases in MET and GAB1 levels, providing novel mechanistic insight into how BRAFV600E mutant melanoma is primed for HGF-mediated rescue. We also determined that tumor-derived HGF, not systemic HGF, may be required to convey resistance to BRAF inhibition in vivo and that resistance could be reversed following treatment with AMG 337, a selective MET inhibitor. In summary, these findings support the clinical evaluation of MET-directed targeted therapy to circumvent resistance to BRAF and MEK inhibitors in BRAFV600E mutant melanoma. In addition, the induction of MET following treatment with BRAF and MEK inhibitors has the potential to serve as a predictive biomarker for identifying patients best suited for MET inhibitor combination therapy.
治疗耐药性是实现靶向治疗持久临床反应的主要障碍,这凸显了阐明耐药潜在机制并确定克服这一挑战策略的必要性。越来越多的数据表明,酪氨酸激酶MET在介导BRAFV600E突变型黑色素瘤对BRAF抑制剂的耐药性中起作用。在本研究中,我们观察到HGF/MET轴在介导BRAFV600E和NRAS突变型黑色素瘤模型对BRAF和MEK抑制剂的耐药性中起主导作用。此外,我们表明,MAPK通路抑制会导致MET和GAB1水平迅速升高,这为BRAFV600E突变型黑色素瘤如何为HGF介导的挽救做好准备提供了新的机制性见解。我们还确定,肿瘤来源的HGF而非全身HGF可能是体内传递对BRAF抑制耐药性所必需的,并且在用选择性MET抑制剂AMG 337治疗后,耐药性可以逆转。总之,这些发现支持对MET靶向治疗进行临床评估,以规避BRAFV600E突变型黑色素瘤对BRAF和MEK抑制剂的耐药性。此外,BRAF和MEK抑制剂治疗后MET的诱导有可能作为一种预测生物标志物,用于识别最适合MET抑制剂联合治疗的患者。