Huang Fangjin, Ma Zhaoxuan, Pollan Sara, Yuan Xiaopu, Swartwood Steven, Gertych Arkadiusz, Rodriguez Maria, Mallick Jayati, Bhele Sanica, Guindi Maha, Dhall Deepti, Walts Ann E, Bose Shikha, de Peralta Venturina Mariza, Marchevsky Alberto M, Luthringer Daniel J, Feller Stephan M, Berman Benjamin, Freeman Michael R, Alvord W Gregory, Vande Woude George, Amin Mahul B, Knudsen Beatrice S
Department of Biomedical Sciences Cedars-Sinai Medical Center Los Angeles California 90048 USA.
Departments of Surgery Cedars-Sinai Medical Center Los Angeles California 90048 USA.
J Pathol Clin Res. 2016 Jul 1;2(4):210-222. doi: 10.1002/cjp2.49. eCollection 2016 Oct.
The limited clinical success of anti-HGF/MET drugs can be attributed to the lack of predictive biomarkers that adequately select patients for treatment. We demonstrate here that quantitative digital imaging of formalin fixed paraffin embedded tissues stained by immunohistochemistry can be used to measure signals from weakly staining antibodies and provides new opportunities to develop assays for detection of MET receptor activity. To establish a biomarker panel of MET activation, we employed seven antibodies measuring protein expression in the HGF/MET pathway in 20 cases and up to 80 cores from 18 human cancer types. The antibodies bind to epitopes in the extra (EC)- and intracellular (IC) domains of MET (MET4, SP44_MET, D1C2_MET), to MET-pY1234/pY1235, a marker of MET kinase activation, as well as to HGF, pSFK or pMAPK. Expression of HGF was determined in tumour cells (T_HGF) as well as in stroma surrounding cancer (St_HGF). Remarkably, MET4 correlated more strongly with pMET ( = 0.47) than SP44_MET ( = 0.21) or D1C2_MET ( = 0.08) across 18 cancer types. In addition, correlation coefficients of pMET and T_HGF ( = 0.38) and pMET and pSFK ( = 0.56) were high. Prediction models of MET activation reveal cancer-type specific differences in performance of MET4, SP44_MET and anti-HGF antibodies. Thus, we conclude that assays to predict the response to HGF/MET inhibitors require a cancer-type specific antibody selection and should be developed in those cancer types in which they are employed clinically.
抗HGF/MET药物有限的临床疗效可归因于缺乏能充分筛选出适合治疗患者的预测性生物标志物。我们在此证明，通过免疫组织化学对福尔马林固定石蜡包埋组织进行定量数字成像，可用于测量弱染色抗体的信号，并为开发检测MET受体活性的检测方法提供了新机会。为建立MET激活的生物标志物组合，我们使用了7种抗体，检测20例样本以及来自18种人类癌症类型的多达80个组织芯中HGF/MET通路中的蛋白质表达。这些抗体与MET的胞外（EC）和胞内（IC）结构域（MET4、SP44_MET、D1C2_MET）中的表位结合，与MET激酶激活的标志物MET-pY1234/pY1235结合，还与HGF、pSFK或pMAPK结合。在肿瘤细胞（T_HGF）以及癌周围基质（St_HGF）中测定HGF的表达。值得注意的是，在18种癌症类型中，MET4与pMET的相关性（r = 0.47）比SP44_MET（r = 0.21）或D1C2_MET（r = 0.08）更强。此外，pMET与T_HGF的相关系数（r = 0.38）以及pMET与pSFK的相关系数（r = 0.56）都很高。MET激活的预测模型揭示了MET4、SP44_MET和抗HGF抗体在不同癌症类型中的性能差异。因此，我们得出结论，预测对HGF/MET抑制剂反应的检测方法需要针对癌症类型进行特异性抗体选择，并且应该在临床应用的那些癌症类型中开发。
