The effect of 1,25(OH)2D3 and 17-beta estradiol on PKC delta and PKC epsilon expression of MCF-7 breast cancer and MCF10-A normal cells in vitro

This thesis is an investigation of the effect of 1,25(OH)2D 3 on Protein Kinase C (PKC) expression of normal and malignant breast epithelial cells. In this study, 1,25(OH)2D3 induced a rapid and persistent increase in PKCdelta expression up to 6 hour after the treatment in MCF-7 breast carcinoma and MCF-10A non transformed breast cells. On the other hand 17-beta Estradiol treatment significantly down regulated PKCdelta expression by MCF-7 cells in a dose-dependent manner but had no effect on PKCdelta expression by MCF-10A cells.; 1,25(OH)2D3 inhibits MCF-7 human breast cancer cell growth even in the presence of 17-beta Estradiol. This treatment resulted in a two-fold increase in PKCdelta expression in the MCF-7 cell line. On the other hand co-treatment of MCF10-A cells with 1,25(OH)2D 3 and 17-betaEstradiol had no effect on PKCdelta expression.; Treatment with 50 nM 1,25(OH)2D3 produced a time dependent decrease in PKCepsilon in MCF-7 cells but had no effect on PKCepsilon expression by MCF10-A cells. On the other hand, 17-beta Estradiol treatment resulted in a time- and dose-dependent up-regulation in PKCepsilon. This effect seems to be specific to MCF-7 malignant cells and did not appear in MCF10-A normal epithelial cells. (Abstract shortened by UMI.)...