Progesterone enhances cytokine-stimulated nitric oxide synthase II expression and cell death in human breast cancer cells.
The presence of hormone receptors is related to survival outcome in breast cancer. Previous results from our laboratory established a correlation between the presence of nitric oxide synthase II (NOSII) and nitric oxide (NO) production with progesterone receptors in a series of human breast tumours. Furthermore, this was directly related to a lower tumour grade and a lower proliferation rate of the tumour cells. To examine these results in further detail, the effect of progesterone (Pg) and 17beta-oestradiol (E2) on NOSII expression was analysed in the human breast cancer cell line MCF-7. By Northern blot and promoter activity, we show that a cytokine mix (TNF-alpha, IL-beta, and IFN-gamma) induces NOSII transcription after 6 h stimulation. In the absence of cytokines, neither hormone affects NOSII expression. However, Pg but not E2, enhances cytokine-induced NOSII transcription as well as NO synthesis, mainly by cooperation with gamma-interferon. The increase in NO accumulation in the media induced by addition of Pg to the cytokine treatment significantly increases cell death, mainly accounted for by apoptosis, as compared to the effect of cytokines alone. Our findings help clarify the role of steroid hormones in NOSII expression as well as the effect on cell viability and may suggest novel approaches towards hormonotherapy and the treatment of cancer.
Bentrari
Fatima
F
EPHE INSERM 517, Faculty of Medicine, University of Bourgogne, Dijon, France.
Arnould
Laurent
L
Jackson
Antony P
AP
Jeannin
Jean-Francois
JF
Pance
Alena
A
D000230:Adenocarcinoma / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000494:pharmacology*; D004338:Drug Combinations; D004357:Drug Synergism; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D052247:Nitric Oxide Synthase Type II; D011374:Progesterone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D014158:Transcription, Genetic / Q000187:drug effects
D016207:Cytokines; D004338:Drug Combinations; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011374:Progesterone; D004958:Estradiol; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II