Estrogen-Induced Apoptosis of Breast Epithelial Cells Is Blocked by NO/cGMP and Mediated by Extranuclear Estrogen Receptors
| Autor: | Irida Kastrati, Gregory R. J. Thatcher, Praneeth D. Edirisinghe, Gihani T. Wijewickrama |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
medicine.medical_specialty
Programmed cell death Estrogen receptor Apoptosis Caspase 3 Biology Nitric Oxide Article Culture Media Serum-Free Cell Line Phosphatidylinositol 3-Kinases Endocrinology Estrogen Receptor Modulators Internal medicine medicine Humans Breast Protein kinase A Cyclic GMP Phosphoinositide-3 Kinase Inhibitors Estradiol Kinase Epithelial Cells Receptors Estrogen Female Nitric Oxide Synthase Signal transduction Soluble guanylyl cyclase Proto-Oncogene Proteins c-akt Signal Transduction |
| Zdroj: | Endocrinology. 151:5602-5616 |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/en.2010-0378 |
| Popis: | Estrogen action, via both nuclear and extranuclear estrogen receptors (ERs), induces a variety of cellular signals that are prosurvival or proliferative, whereas nitric oxide (NO) can inhibit apoptosis via caspase S-nitrosylation and via activation of soluble guanylyl cyclase to produce cGMP. The action of 17β-estradiol (E2) at ER is known to elicit NO signaling via activation of NO synthase (NOS) in many tissues. The MCF-10A nontumorigenic, mammary epithelial cell line is genetically stable and insensitive to estrogenic proliferation. In this cell line, estrogens or NOS inhibitors alone had no significant effect, whereas in combination, apoptosis was induced rapidly in the absence of serum; the presence of inducible NOS was confirmed by proteomic analysis. The application of pharmacological agents determined that apoptosis was dependent upon NO/cGMP signaling via cyclic GMP (cGMP)-dependent protein kinase and could be replicated by inhibition of the phosphatidylinositol 3 kinase/serine-threonine kinase pathway prior to addition of E2. Apoptosis was confirmed by nuclear staining and increased caspase-3 activity in E2 + NOS inhibitor-treated cells. Apoptosis was partially inhibited by a pure ER antagonist and replicated by agonists selective for extranuclear ER. Cells were rescued from E2-induced apoptosis after NOS blockade, by NO-donors and cGMP pathway agonists; preincubation with NO donors was required. The NOS and ER status of breast cancer tissues is significant in etiology, prognosis, and therapy. In this study, apoptosis of preneoplastic mammary epithelial cells was triggered by estrogens via a rapid, extranuclear ER-mediated response, after removal of an antiapoptotic NO/cGMP/cGMP-dependent protein kinase signal. |
| Databáze: | OpenAIRE |
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