A New Insulin-Like Growth Factor Binding Protein and Its Role in Breast Cancer and Cell Growth
Annual summary rept. 19 Aug 1998-18 Aug 1999
WASHINGTON UNIV SEATTLE
Pagination or Media Count:
Mac25 is the first member of the IGFBP-rP family IGFBP-rP1. IGFBP-rP1 is expressed in normal human mammary epithelial cells HMECs and upregulated in senescent HMECs. IGFBP-rP1 is not expressed in twelvesixteen breast cancer cell lines and its expression is absent in estrogen receptor positive ER breast cancer cell lines. IGFBP-rP1 may regulate HMEC growth. We tested the hypothesis that it suppresses growth in ER breast cancer cells by transducing the cDNA into normal and human breast tumor cultures. We are testing the function of IGFBP-rP1 in normal HMECs by transducing AG11132 normal cells. We will determine if IGFBP-rP1-rP1 is regulated at the transcriptional level by characterization of the promoter. We are determining the binding properties of IGFBP-rP1 by growth assays in presence of IGF-I, IGF-II, R3-IGF-I, and R6-IGF-II and immunoprecipitationphosphatase assays. We have determined IGFBP-rP1 tissue specificity by mRNA in situ hybridization.
- Medicine and Medical Research