Growth suppression of colorectal cancer expressing S492R EGFR by monoclonal antibody CH12 / 医学前沿

Colorectal cancer (CRC) is a common malignant tumor in the digestive tract, and 30%-85% of CRCs express epidermal growth factor receptors (EGFRs). Recently, treatments using cetuximab, also named C225, an anti-EGFR monoclonal antibody, for CRC have been demonstrated to cause an S492R mutation in EGFR. However, little is known about the biological function of S492R EGFR. Therefore, we attempted to elucidate its biological function in CRC cells and explore new treatment strategies for this mutant form. Our study indicated that EGFR and S492R EGFR accelerate the growth of CRC cells in vitro and in vivo and monoclonal antibody CH12, which specifically recognizes an EGFR tumor-specific epitope, can bind efficiently to S492R EGFR. Furthermore, mAb CH12 showed significantly stronger growth suppression activities and induced a more potent antibody-dependent cellular cytotoxicity effect on CRC cells bearing S492R EGFR than mAb C225. mAb CH12 obviously suppressed the growth of CRC xenografts with S492R EGFR mutations in vivo. Thus, mAb CH12 may be a promising therapeutic agent in treating patients with CRC bearing an S492R EGFR mutation.

The study of secretory clusterin on the biological behaviors of non-small cell lung cancer cells / 中国癌症杂志

Background and purpose: Primary study showed that clusterin was associated with tumorigenicity. The goal of the study is to investigate the role of secretory clusterin in non-small cell lung cancer cell A549/H460. Methods: The lung cancer cell A549/H460 was treated with purified secretory clusterin, the Boyden Chamber migration assay was used to detected the migration of the lung cancer cell;the CCK8 assay was used to detected the growth of the cells;microRNA expression spectrum in H460 treated with secretory clusterin was analyzed, after that, we used the real-time florescence quantification detected the expression of microRNA in H460, and the biological function of microRNA molecular mechanisms of secretory clusterin was analyzed. Results: Secretory clusterin promoted the migration in A549/H460 (P<0.000 1);Secretory clusterin inhibited the growth in H460/A549 (P<0.000 1);MicroRNA-302b-3p, microRNA-23a-5p and microRNA-101-5p was overexpressed in H460 when treated with secretory clusterin. Conclusion:Secretory clusterin could promote the migration and inhibit the growth of lung cancer cell;It could change the microRNA expression spectrum as well. Our studies revealed that secretory clusterin could be used as a tool for further study, and it is a potential target in the treatment of lung cancer.

Preparation and identification of a 9B9 monoclonal antibody specifically targeting EGFRvⅢ/EGFR / 中国肿瘤生物治疗杂志

Objective:To prepare and identify monoclonal antibody specifically targeting epidermal growth factor receptor(EGFR) and(or) epidermal growth factor receptor vⅢ(EGFRvⅢ),and to investigate its inhibitory effects on human hepatocellular carcinoma Huh7-EGFRvⅢ cell-and epidermal carcinoma A431 cell-implanted tumors in nude mice.Methods: BALB/c mice were immunized with 3T3 cells stably transfected with EGFRvⅢ(3T3-EGFRvⅢ).Immunized spleen cells were fused with myeloma SP2/0 cells,and anti-EGFRvⅢ monoclonal antibody positive hybridoma cells(named 9B9 antibody and 9B9 cells,respectively) were selected and identified by ELISA.The specific interaction between 9B9 antibody and EGFRvⅢ/EGFR antigen was detected by Western blotting and immunofluorescence assay.Huh7-EGFRvⅢ cell-(human hepatocellular carcinoma Huh7 cells stably transfected with EGFRvⅢ) and epidermal cell carcinoma A431 cell-bearing mouse models were established and were divided into PBS group,Cetuximab group and 9B9 antibody group.Then,anti-tumor effect of 9B9 antibody was examined and compared with those of PBS and Cetuximab.Results: A monoclonal antibody,named 9B9 antibody,was obtained by hybridoma technique and it reacted with both EGFRvⅢ antigen and EGFR antigen as detected by Western blotting and immunofluorescence.The inhibitory rates of Cetuximab and 9B9 antibody against Huh7-EGFRvⅢ cells-implanted tumors were 42% and 46%,respectively,and those against A431 cells-implanted tumors were 85% and 86%,respectively.Conclusion: 9B9 monoclonal antibody can effectively inhibit the growth of human hepatocellular carcinoma cell-and epidermal cell carcinoma cell-implanted tumors,and the effects resemble that of Cetuximab.