Published in Cancer Detection and Prevention 2003; 27(6).
Induction of cell cycle arrest and apoptosis in human cervix carcinoma cells during therapy by cisplatinaCell Cycle Regulation Unit, Institute of Cancer Research, Faculty of Medicine, University of Vienna, Borschkegasse 8a, A-1090 Vienna, Austria bDepartment of Pathological Physiology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
The aim of the therapy of human malignancies is the inhibition of cell proliferation and/or induction of apoptosis. We studied the kinetics of the morphological and biochemical changes in HeLa cells during chemotherapy by cisplatin (CP). Apoptosis was evaluated by scoring of cells exhibiting changes characteristic for early and late stages of apoptosis as determined by Hoechst 33258 staining and by examination of positive reaction for activated caspase-3. Expression and intracellular localization of distinct proteins was analyzed by immunoblotting of subcellular fractions and segregation of nucleoli by immunocytochemistry. Chromatin fragmentation characteristic for apoptosis was observed in single cells after 3 h cisplatin. A strong cytoplasmic accumulation of cytochrome C detected by immunoblotting 6 h post-treatment was accompanied by an activation of caspase-9. Neither inhibition of cell division nor blocking of DNA replication preceded the onset of apoptosis. Our results show that after short treatment by CP, cell proliferation and apoptosis concomitantly occurred.