Hsi Eric D, Steinle Roxanne, Balasa Balaji, Szmania Susann, Draksharapu Aparna, Shum Benny P, Huseni Mahrukh, Powers David, Nanisetti Amulya, Zhang Yin, Rice Audie G, van Abbema Anne, Wong Melanie, Liu Gao, Zhan Fenghuang, Dillon Myles, Chen Shihao, Rhodes Susan, Fuh Franklin, Tsurushita Naoya, Kumar Shankar, Vexler Vladimir, Shaughnessy John D, Barlogie Bart, van Rhee Frits, Hussein Mohamad, Afar Daniel E H, Williams Marna B
Clinical Pathology, Cleveland Clinic Foundation, Cleveland, Ohio, USA.
Clin Cancer Res. 2008 May 1;14(9):2775-84. doi: 10.1158/1078-0432.CCR-07-4246.
We generated a humanized antibody, HuLuc63, which specifically targets CS1 (CCND3 subset 1, CRACC, and SLAMF7), a cell surface glycoprotein not previously associated with multiple myeloma. To explore the therapeutic potential of HuLuc63 in multiple myeloma, we examined in detail the expression profile of CS1, the binding properties of HuLuc63 to normal and malignant cells, and the antimyeloma activity of HuLuc63 in preclinical models.
CS1 was analyzed by gene expression profiling and immunohistochemistry of multiple myeloma samples and numerous normal tissues. HuLuc63-mediated antimyeloma activity was tested in vitro in antibody-dependent cellular cytotoxicity (ADCC) assays and in vivo using the human OPM2 xenograft model in mice.
CS1 mRNA was expressed in >90% of 532 multiple myeloma cases, regardless of cytogenetic abnormalities. Anti-CS1 antibody staining of tissues showed strong staining of myeloma cells in all plasmacytomas and bone marrow biopsies. Flow cytometric analysis of patient samples using HuLuc63 showed specific staining of CD138+ myeloma cells, natural killer (NK), NK-like T cells, and CD8+ T cells, with no binding detected on hematopoietic CD34+ stem cells. HuLuc63 exhibited significant in vitro ADCC using primary myeloma cells as targets and both allogeneic and autologous NK cells as effectors. HuLuc63 exerted significant in vivo antitumor activity, which depended on efficient Fc-CD16 interaction as well as the presence of NK cells in the mice.
These results suggest that HuLuc63 eliminates myeloma cells, at least in part, via NK-mediated ADCC and shows the therapeutic potential of targeting CS1 with HuLuc63 for the treatment of multiple myeloma.
我们制备了一种人源化抗体HuLuc63，其特异性靶向CS1（细胞周期蛋白D3亚群1、CRACC和信号淋巴细胞激活分子家族成员7），这是一种先前与多发性骨髓瘤无关的细胞表面糖蛋白。为了探索HuLuc63在多发性骨髓瘤中的治疗潜力，我们详细研究了CS1的表达谱、HuLuc63与正常及恶性细胞的结合特性，以及HuLuc63在临床前模型中的抗骨髓瘤活性。
通过基因表达谱分析和免疫组织化学方法，对多发性骨髓瘤样本及众多正常组织中的CS1进行分析。在体外抗体依赖性细胞毒性（ADCC）试验中测试HuLuc63介导的抗骨髓瘤活性，并在小鼠体内使用人OPM2异种移植模型进行测试。
在532例多发性骨髓瘤病例中，超过90%表达CS1 mRNA，无论细胞遗传学异常情况如何。组织的抗CS1抗体染色显示，所有浆细胞瘤和骨髓活检中的骨髓瘤细胞均有强染色。使用HuLuc63对患者样本进行流式细胞术分析显示，CD138+骨髓瘤细胞、自然杀伤（NK）细胞、NK样T细胞和CD8+ T细胞有特异性染色，而在造血CD34+干细胞上未检测到结合。以原代骨髓瘤细胞为靶细胞，同种异体和自体NK细胞为效应细胞，HuLuc63在体外表现出显著的ADCC活性。HuLuc63在体内发挥了显著的抗肿瘤活性，这取决于有效的Fc-CD16相互作用以及小鼠体内NK细胞的存在。
这些结果表明，HuLuc63至少部分通过NK介导的ADCC消除骨髓瘤细胞，并显示了用HuLuc63靶向CS1治疗多发性骨髓瘤的治疗潜力。
