title: 17beta-estradiol induces both up-regulation and processing of cyclin E in a calpain-dependent manner in MCF-7 breast cancer cells.
abstract: In the current study, we investigated whether 17beta-estradiol (E2) induces cyclin E expression and triggers cyclin E processing via calpain in MCF-7 breast cancer cells. We found that E2 induced increased expression of cyclin E in a slow and persistent manner, and a rapid yet sustained processing of cyclin E. In addition, estrogenic ethanol was able to stimulate cyclin E truncation. Calpeptin or ALLN greatly suppressed the E2-triggered cyclin E processing and its expression, suggesting a calpain-mediated action for E2. Finally, the E2-induced effects could also be significantly suppressed by BAPTA or U0126, indicating involvement of calcium/ERK signaling. Taken together, these results show that estrogen may contribute to both up-regulation and proteolysis of cyclin E through calpain in MCF-7 cells.
authors.affiliation: Department of Physiology/Cancer Research Group, School of Basic Medicine, Guiyang Medical University, Guiyang 550004, Guizhou, China.
authors.forename: Jianmei
authors.initials: J
authors.lastname: Hou
authors.forename: Xudong
authors.initials: X
authors.lastname: Wang
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
authors.forename: Zhuting
authors.initials: Z
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: An
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: He
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D002070:Butadienes; D002118:Calcium / Q000378:metabolism; D002154:Calpain / Q000037:antagonists & inhibitors / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000187:drug effects*; D002614:Chelating Agents / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism*; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005260:Female; D006801:Humans; D009570:Nitriles; D015398:Signal Transduction / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D002070:Butadienes; D002614:Chelating Agents; D019927:Cyclin E; D009570:Nitriles; C113580:U 0126; D004958:Estradiol; D004533:Egtazic Acid; D048049:Extracellular Signal-Regulated MAP Kinases; D002154:Calpain; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium