BACKGROUND: Apoptosis, also termed programmed cell death, is an active form of cellular degradation in contrast to the passive, inflammatory necrosis. Triggering apoptosis in tumor cells is a significant aim of chemotherapeutic treatment. MATERIALS AND METHODS: In this investigation the rate of apoptosis in human mammary carcinoma cell spheroids and monolayers was quantified following treatment with doxorubicin using various concentrations and incubation times. These data were compared with results of standardized clonogenicity assays, spheroid volume growth curves, and flowcytometric cell cycle analysis and BrdU-labeling. RESULTS: Whereas spheroid volume growth and cellular clonogenicity were in excellent accordance with the well-established chemosensitivity of the three cell lines, the incidence of apoptosis did not reflect the different susceptibility of the cell lines to doxorubicin in a systematic way. On the other hand, theoretical considerations showed that the relatively low proportion of apoptosis can account for the relatively large decrease in spheroid volume, as observed in doxorubicin-treated T47D spheroids. CONCLUSIONS: The experimental data suggest that suppression of apoptosis is not an obligatory feature of multi-drug resistant cell lines, and that resistance is rather correlated with an increase in DNA-synthesis.
BACKGROUND: Apoptosis, also termed programmed cell death, is an active form of cellular degradation in contrast to the passive, inflammatory necrosis. Triggering apoptosis in tumor cells is a significant aim of chemotherapeutic treatment. MATERIALS AND METHODS: In this investigation the rate of apoptosis in human mammary carcinoma cell spheroids and monolayers was quantified following treatment with doxorubicin using various concentrations and incubation times. These data were compared with results of standardized clonogenicity assays, spheroid volume growth curves, and flowcytometric cell cycle analysis and BrdU-labeling. RESULTS: Whereas spheroid volume growth and cellular clonogenicity were in excellent accordance with the well-established chemosensitivity of the three cell lines, the incidence of apoptosis did not reflect the different susceptibility of the cell lines to doxorubicin in a systematic way. On the other hand, theoretical considerations showed that the relatively low proportion of apoptosis can account for the relatively large decrease in spheroid volume, as observed in doxorubicin-treated T47D spheroids. CONCLUSIONS: The experimental data suggest that suppression of apoptosis is not an obligatory feature of multi-drug resistant cell lines, and that resistance is rather correlated with an increase in DNA-synthesis.
Authors: Hari R Kumar; Xiaoling Zhong; Derek J Hoelz; Frederick J Rescorla; Robert J Hickey; Linda H Malkas; John A Sandoval Journal: Pediatr Surg Int Date: 2008-09-17 Impact factor: 1.827
Authors: Hans Ulrich Schmelz; Michael Abend; Matthias Port; Michael Schwerer; Ekkehard W Hauck; Wolfgang Weidner; Christoph Sparwasser Journal: Urol Res Date: 2004-04-29