Knudsen Beatrice S, Zhao Ping, Resau James, Cottingham Sandra, Gherardi Ermanno, Xu Eric, Berghuis Bree, Daugherty Jennifer, Grabinski Tessa, Toro Jose, Giambernardi Troy, Skinner R Scot, Gross Milton, Hudson Eric, Kort Eric, Lengyel Ernst, Ventura Aviva, West Richard A, Xie Qian, Hay Rick, Vande Woude George, Cao Brian
Department of Pathology, University of Washington Medical Center, NE Pacific, Seattle, WA, USA.
Appl Immunohistochem Mol Morphol. 2009 Jan;17(1):57-67. doi: 10.1097/PAI.0b013e3181816ae2.
The inappropriate expression of the c-MET cell surface receptor in many human solid tumors necessitates the development of companion diagnostics to identify those patients who could benefit from c-MET targeted therapies. Tumor tissues are formalin fixed and paraffin embedded (FFPE) for histopathologic evaluation, making the development of an antibody against c-MET that accurately and reproducibly detects the protein in FFPE samples an urgent need. We have developed a monoclonal antibody (mAb), designated MET4, from a panel of MET-avid mAbs, based on its specific staining pattern in FFPE preparations. The accuracy of MET4 immunohistochemistry (MET4-IHC) was assessed by comparing MET4-IHC in FFPE cell pellets with immunoblotting analysis. The technical reproducibility of MET4-IHC possessed a percentage coefficient of variability of 6.25% in intra-assay and interassay testing. Comparison with other commercial c-MET antibody detection reagents demonstrated equal specificity and increased sensitivity for c-MET detection in prostate tissues. In cohorts of ovarian cancers and gliomas, MET4 reacted with ovarian cancers of all histologic subtypes (strong staining in 25%) and with 63% of gliomas. In addition, MET4 bound c-MET on the surfaces of cultured human cancer cells and tumor xenografts. In summary, the MET4 mAb accurately and reproducibly measures c-MET expression by IHC in FFPE tissues and can be used for molecular imaging in vivo. These properties encourage further development of MET4 as a multipurpose molecular diagnostics reagent to help to guide appropriate selection of patients being considered for treatment with c-MET-antagonistic drugs.
c-MET细胞表面受体在许多人类实体瘤中表达异常，因此需要开发伴随诊断方法，以识别那些可能从c-MET靶向治疗中获益的患者。肿瘤组织经福尔马林固定和石蜡包埋（FFPE）用于组织病理学评估，这使得开发一种能在FFPE样本中准确且可重复地检测该蛋白的抗c-MET抗体成为迫切需求。我们从一组MET亲和性单克隆抗体中开发出一种单克隆抗体（mAb），命名为MET4，基于其在FFPE制剂中的特异性染色模式。通过将FFPE细胞沉淀中的MET4免疫组织化学（MET4-IHC）与免疫印迹分析相比较，评估了MET4-IHC的准确性。MET4-IHC的技术重现性在批内和批间测试中的变异系数百分比为6.25%。与其他商业c-MET抗体检测试剂比较表明，在前列腺组织中，MET4对c-MET检测具有相同的特异性且灵敏度更高。在卵巢癌和神经胶质瘤队列中，MET4与所有组织学亚型的卵巢癌（25%强染色）以及63%的神经胶质瘤发生反应。此外，MET4与培养的人类癌细胞和肿瘤异种移植瘤表面的c-MET结合。总之，MET4单克隆抗体通过免疫组织化学在FFPE组织中准确且可重复地检测c-MET表达，可用于体内分子成像。这些特性促使MET4进一步发展成为一种多功能分子诊断试剂，以帮助指导对考虑使用c-MET拮抗药物治疗的患者进行适当选择。
