Abstract:
New targeted treatments are urgently needed to improve triple-negative breast cancer (TNBC) patient survival. Previously, we identified the cell surface protein A Disintegrin And Metalloprotease 8 (ADAM8) as a driver of TNBC tumor growth and spread via its metalloproteinase and disintegrin (MP and DI) domains. In proof-of-concept studies, we demonstrated that a monoclonal antibody (mAb) that simultaneously inhibits both domains represents a promising therapeutic approach. Here, we screened a hybridoma library using a multistep selection strategy, including flow cytometry for Ab binding to native conformation protein and in vitro cell-based functional assays to isolate a novel panel of highly specific human ADAM8 dual MP and DI inhibitory mAbs, called ADPs. The screening of four top candidates for in vivo anti-cancer activity in an orthotopic MDA-MB-231 TNBC model of ADAM8-driven primary growth identified two lead mAbs, ADP2 and ADP13. Flow cytometry, hydrogen/deuterium exchange-mass spectrometry (HDX-MS) and alanine (ALA) scanning mutagenesis revealed that dual MP and DI inhibition was mediated via binding to the DI. Further testing in mice showed ADP2 and ADP13 reduce aggressive TNBC characteristics, including locoregional regrowth and metastasis, and improve survival, demonstrating strong therapeutic potential. The continued development of these mAbs into an ADAM8-targeted therapy could revolutionize TNBC treatment.
摘要:
迫切需要新的靶向治疗来提高三阴性乳腺癌(TNBC)患者的生存率。以前,我们确定细胞表面蛋白A解整合素和金属蛋白酶8(ADAM8)是通过其金属蛋白酶和解整合素(MP和DI)结构域促进TNBC肿瘤生长和扩散的驱动因素。在概念验证研究中,我们证明,同时抑制两个结构域的单克隆抗体(mAb)代表了一种有希望的治疗方法。这里,我们使用多步选择策略筛选了杂交瘤文库,包括用于Ab与天然构象蛋白质结合的流式细胞术和体外基于细胞的功能测定,以分离出一组新型的高度特异性人类ADAM8双重MP和DI抑制性mAb,叫做ADPs。在ADAM8驱动的原代生长的原位MDA-MB-231TNBC模型中体内抗癌活性的四个最高候选物的筛选确定了两个前导mAb,ADP2和ADP13。流式细胞术,氢/氘交换质谱(HDX-MS)和丙氨酸(ALA)扫描诱变表明,MP和DI双重抑制是通过与DI结合介导的。在小鼠中的进一步测试显示ADP2和ADP13降低侵袭性TNBC特征,包括局部再生长和转移,提高生存率,显示出强大的治疗潜力。这些mAb继续发展为ADAM8靶向治疗可以彻底改变TNBC治疗。