Protein Kinase C Processes and Their Relation to Apoptosis in Human Breast Carcinoma Cells

Abstract : To complete the first specific aim of this project VP-16, taxol, okadaic acid, and calyculin A were used to screen for apoptosis in the human breast carcinoma cell line MDA-MB-231. Characterization of apoptosis was investigated by concentration-response and time course studies using MDA-MB-231 cells evaluated by morphology. Appropriate concentrations of calyculin A were selected for additional characterization of apoptosis in MDA-MB-231 cells since calyculin A was the most effective compound. DNA fragmentation was the next hallmark of apoptosis measured using calyculin A. Calyculin A does not promote internucleosomal DNA fragmentation, but does induce heavy molecular weight DNA fragmentation at concentrations that induce apoptotic morphology in MDA-MB-231 cells. This compound instigates apoptotic morphology and heavy molecular weight DNA fragmentation in MDA-MB-231 cells characteristic of apoptosis. Future experiments on calyculin AEs ability to induce apoptosis, and the effects of Protein Kinase C on calyculin A induced apoptosis, will be carried out using MDA-MB-231 cells as outlined in the Statement of Work.