METHODS: ROR1 expression in tumor tissues and cell lines was analyzed by immunohistochemistry and flow cytometry. Antibodies from mouse hybridomas were humanized by the complementarity-determining region (CDR) grafting technique. Surface plasmon resonance spectroscopy, ELISA assay and flow cytometry were employed to characterize humanized antibodies. In vitro cellular assay and in vivo mouse experiment were conducted to comprehensively evaluate anti-tumor activity of these antibodies.
RESULTS: ROR1 exhibited dramatically higher expression in lung adenocarcinoma, liver cancer and breast cancer, and targeting ROR1 by short-hairpin RNAs significantly inhibited proliferation and migration of cancer cells. Two humanized ROR1 monoclonal antibodies were successfully developed, named h1B8 and h6D4, with high specificity and affinity to ROR1 protein. Moreover, these two antibodies effectively suppressed tumor growth in the lung cancer xenograft mouse model, c-Myc/Alb-cre liver cancer transgenic mouse model and MMTV-PyMT breast cancer mouse model.
CONCLUSIONS: Two humanized monoclonal antibodies targeting ROR1, h1B8 and h6D4, were successfully developed and exhibited remarkable anti-tumor activity in vivo.
方法:用免疫组织化学和流式细胞术分析肿瘤组织和细胞系中ROR1的表达。通过互补决定区(CDR)移植技术将来自小鼠杂交瘤的抗体人源化。表面等离子体共振光谱,采用ELISA测定和流式细胞术表征人源化抗体。进行了体外细胞测定和体内小鼠实验以全面评估这些抗体的抗肿瘤活性。
结果:ROR1在肺腺癌中表达明显增高,肝癌和乳腺癌,短发夹RNA靶向ROR1显著抑制癌细胞的增殖和迁移。成功研制出两种人源化ROR1单克隆抗体,定名为h1B8和h6D4,对ROR1卵白具有较高的特异性和亲和力。此外,这两种抗体在肺癌异种移植小鼠模型中有效抑制肿瘤生长,c-Myc/Alb-cre肝癌转基因小鼠模型和MMTV-PyMT乳腺癌小鼠模型。
结论:成功开发了两种靶向ROR1h1B8和h6D4的人源化单克隆抗体,并在体内表现出显著的抗肿瘤活性。