抗HER2人源化单克隆抗体体内外抗肿瘤活性评价方法的建立

A method for evaluation of in vitro and in vivo anti-tumor activity of anti-Her2 humanized monoclonal antibody

目的建立抗HER2人源化单克隆抗体体内外抗肿瘤活性的评价方法。方法利用HER2表达阳性的人乳腺癌细胞系BT474建立抗HER2单抗体内外活性评价方法,对上海市细胞工程重点实验室制备的抗HER2人源化单抗的体外生物学活性、抗体依赖的细胞介导的细胞毒性、对BT474荷瘤裸鼠的治疗作用及荷瘤裸鼠瘤体组织H E染色及免疫组化检测rh HER2mAb的分布与Herceptin进行了比较研究。结果建立了完整的该人源化单抗的体内外活性评价方法,测评结果显示,上海市细胞工程重点实验室制备的抗HER2人源化单抗在体外有效抑制BT474细胞增殖,与Herceptin体外生物学活性相似,EC50分别为148.3和145.9ng/ml;可通过ADCC效应杀伤BT474细胞,与Herceptin的EC50值一致,分别为185.0和183.9ng/ml;抑制BT474裸鼠异种移植模型肿瘤的生长,与无关抗体治疗组或PBS治疗组相比具有统计学差别(P<0.05),与Herceptin抑制能力接近,4mg/kg剂量组相比没有统计学差别;免疫组织化学检测显示抗体集中分布于肿瘤组织。结论建立的评价方法可对抗HER2单抗的抗肿瘤活性进行客观准确的评价,国内研制的抗HER2人源化单克隆抗体与进口同种抗体相比具有相同的体内外活性。

Objective:To establish an evaluation system for in vitro and in vivo anti-tumor activity of anti-HER2 humanized monoclonal antibody(rhHER2-mAb). Methods: An evaluation system was established with HER2 positive cell line BT-474 and was used to detect the in vitro bio-activity and antibody dependent cell mediated-cytotoxicity (ADCC) of rhHER2-mAb, which was produced by Shanghai Key Laboratory of Cell Engineering. The in vivo anti-tumor effect and biodistribution of the rhHER2-mAb were compared with those of Herceptin in a BT-474 xenograft nude mice model. Results: The evaluation system has been successfully established and has been used to evaluate the anti-tumor effect of rhHER2-mAb. The results showed that rhHER2-mAb inhibited the proliferation of BT-474 cell line effectively. The inhibitiory effect of rhHER2-mAb (EC_~50 , 148.3 ng/ml) was similar to that of Herceptin (EC_~50 , 145.9 ng/ml). The rhHER2-mAb killed the cell line BT-474 (EC_~50 , 185.0 ng/ml) through ADCC effect as Herceptin did (EC_~50 , 183.9 ng/ml). The rhHER2-mAb also inhibited tumor growth of the BT-474 xenograft nude mice model, and the anti-tumor effect was more potent than that of PBS treatment group ^(P< ^0.05). However, the anti-tumor effect of rhHER2-mAb was similar to that of Herceptin treatment group (4 mg/kg). Immunohistochemistry found that the antibody localized at the tumor site. Conclusion: The evaluation system we established can be used as a tool to evaluate the anti-tumor effect of rhHER2-mAb. The in vitro and in vivo biological activity of the rhHER2-mAb produced by the Shanghai Key Laboratory of Cell Engineering is similar to that of Herceptin.