Annexin A5 as a New Potential Biomarker for Cisplatin-Induced Toxicity in Human Kidney Epithelial Cells

Cisplatin is a member of platinum-containing anti-cancer drugs that causes cross-linking of DNA and ultimately cancer cell apoptosis. The therapeutic function of cisplatin on various types of cancers has been widely reported but the side effects have been discovered together and nephrotoxicity has been regarded as major side effect of cisplatin. To select candidates for new sensitive nephrotoxicity biomarker, we performed proteomic analysis using 2-DE/MALDI-TOF-MS followed by cisplatin treatment in human kidney cell line, HK-2 cells, and compared the results to the gene profi le from microarray composed of genes changed in expression by cisplatin from formerly reported article. Annexin A5 has been selected to be the most potential candidate and it has been identifi ed using Western blot, RT-PCR and cell viability assay whether annexin A5 is available to be a sensitive nephrotoxic biomarker. Treatment with cisplatin on HK-2 cells caused the increase of annexin A5 expression in protein and mRNA levels. Overexpression of annexin A5 blocked HK-2 cell proliferation, indicating correlation between annexin A5 and renal cell toxicity. Taken together, these results suggest the possibility of annexin A5 as a new biomarker for cisplatin-mediated nephrotoxicity.

Cytotoxicity of OKT9 ScFv-Diphtheria Toxin Fusion Immunotoxin on Human Brain Tumor Cell Lines

OBJECTIVE: Immunotoxin therapy is a novel approach for the treatment of tumor, and it has been successfully used in the central nervous system. The purpose of this study is to evaluate the cytotoxicity of OKT9 ScFv-Diphtheria toxin fusion immunotoxin on various human brain tumor cell lines. METHODS: Immunotoxin which was composed of OKT9 ScFv and Diphtheria toxin was made. Its cytotoxicity on glioblastoma cell lines(U87MG, U118MG) and medulloblastoma cell line(TE671) was tested and compared with anti-cancer chemotherapeutic agents. And we also examined the relationship between its cytotoxicity and transferrin receptor expression. RESULTS: It showed most cytotoxicity on U87MG cell line and nearly no effect on U118MG cell line, moderate cytotoxicity on TE671 cell line in sixteen hours exposure experiment. In continuous exposure experiment, it showed moderate cytotoxicity on U118MG cell line, but showed strong cytotoxicity on other cell lines comparable or higher than anti-cancer chemotherapeutic agents. The relationship between its cytotoxicity and transferrin receptor expression was tested using flow cytometry, but no direct relationship could be found. CONCLUSION: Collectively, the result shows the cytotoxic effects of OKT9 ScFv-Diphtheria toxin fusion immunotoxin against various human brain tumor cell lines in continuous exposure experiment. Therefore, we suggest that this immunotoxin could be developed as a potential immunotherapeutic agent in the treatment of various human brain tumor clinically.

Expression of Cell Surface Receptors on Human Glioblastoma Xenograft Model in NOD/SCID Mouse / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: To obtain basic data for development of a glioblastoma-specific immunotoxin, the expression of variable cell surface receptors on a human glioblastoma xenograft model was evaluated, using NOD/SCID mice. MATERIALS AND METHODS: We developed a xenograft model in NOD/SCID mice implanted with a human glioblastoma cell line (U-87MG). Immunohistochemical studies were performed on implanted tumor nodules (n=8) using antibodies against CD71, EGFR, IGF-IRalpha, CXCR4 and IL-4Ralpha. RESULTS: Expression of IL-4Ralpha, in implanted tumornodules, was the highest of the cell surface receptors evaluated in this study. However, the endothelial cells in, and around, the tumor nodules also revealed immunopositivity against IL-4Ralpha. The immunoreactivity of IL-4Ralpha, and other surface receptors such as CD71, IGF-IRalpha and EGFR, was prominent in tumor nodules associated with tumor necrosis. CONCLUSION: IL-4Ralpha would be a possible target for the development of glioblastoma-specific immunotoxin, although there are limitations due to its endothelial expression.