Cyclin E as molecular marker in the management of breast cancer: a review.
Over the past decade numerous molecular markers have been identified that may play a role in breast carcinogenesis and prognosis. The most commonly used markers in clinical practice are the estrogen receptor, progesterone receptor and HER-2/neu. Recent studies found cyclin E to be a promising prognostic indicator in breast cancer and examined its potential as a target for therapy. Further studies demonstrated that cyclin E levels were periodic during the cell cycle, with levels of protein peaking in the G1 phase. This peak in cyclin E levels also correlated with maximum enzymatic function of the cyclin E-cdk2 complex, suggesting a critical role of cyclin E in regulating G1 to S-phase transition. Studies examining the relevance of cyclin E alterations in breast cancer have shown gene amplifications in some breast cancer cell lines, data that provide strong support for the role of cyclin E in breast carcinogenesis. It is believed that the most significant cyclin E alteration is post-translational cleavage of full-length cyclin E into low molecular weight forms that are hyperactive compared to the 50-kDa, full-length protein and correlate with increasing stage and grade of breast cancer. The role of cyclin E in the prognosis and therapy of breast cancer is reviewed according to recent publications.
Lopez-Beltran
Antonio
A
Unit of Anatomic Pathology, Cordoba University Medical School and Reina Sofia University Hospital, Cordoba, Spain. em1lobea@uco.es
MacLennan
Gregory T
GT
Montironi
Rodolfo
R
D015415:Biomarkers / Q000032:analysis; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000628:therapy; D019927:Cyclin E / Q000032:analysis*; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006801:Humans; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D011379:Prognosis; D016019:Survival Analysis
D015415:Biomarkers; D019927:Cyclin E; D051357:Cyclin-Dependent Kinase 2; D010196:Pancreatic Elastase