title: Differential effects of chemotherapeutic agents on the Bcl-2/Bax apoptosis pathway in human breast cancer cell line MCF-7.
abstract: The present study explored the effects of three commonly used chemotherapeutic agents on the Bcl-2/Bax apoptosis pathway and the interaction of these chemotherapeutic drugs with the estradiol-mediated regulation of this pathway. Our results showed that: (1) Treatment of MCF-7 cells with Adriamycin resulted in time- and concentration-dependent decreases in Bcl-2 and increases in Bax mRNA and protein levels. (2) Camptothecin elicited similar trends on Bcl-2 and Bax as Adriamycin, while etoposide, at 50-100 fold (1-5 microM) the effective concentration of Adriamycin and camptothecin, only resulted in an increase in Bax mRNA levels. (3) Adriamycin and camptothecin, but not etoposide, were effective in suppressing estradiol-stimulated increases in Bcl-2 mRNA levels. Our study provides evidence that the Bcl-2/Bax apoptosis pathway may be differentially regulated by chemotherapeutic agents. In addition, interaction between these agents and estradiol on the Bcl-2/Bax apoptosis pathway may also exist.
authors.affiliation: Basic Research Laboratory, NCI-Frederick Cancer Research and Development Center, NIH, MD 21702-1201, USA.
authors.forename: L K
authors.initials: LK
authors.lastname: Leung
authors.forename: T T
authors.initials: TT
authors.lastname: Wang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology*; D002166:Camptothecin / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology; D005260:Female; D006801:Humans; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D051028:bcl-2-Associated X Protein
chemical_list: D000970:Antineoplastic Agents; C494826:BAX protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D005047:Etoposide; D004317:Doxorubicin; D002166:Camptothecin