| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
From the Departments of Clinical Research* and Pathology, Singapore General Hospital, Singapore; and the Department of Anatomy, Faculty of Medicine, National University of Singapore, Singapore, Singapore
Progesterone is an important regulator of growth and differentiation in breast tissues. In this study, the effect of progesterone on cell differentiation was evaluated in the estrogen receptor-negative and progesterone receptor (PR)-negative MDA-MB-231 cell line which was transfected with PR-complementary DNA. Morphological changes were analyzed at the ultrastructural level by scanning and transmission electron microscopy. Progesterone-treated PR-transfected cells exhibited a more protracted and well spread morphology with an increase in organelles such as mitochondria and rough endoplasmic reticulum as compared to the rounded form of control vehicle (0.1% ethanol)-treated PR-transfected cells. Vehicle and progesterone-treated MDA-MB-231 cells transfected with the pSG5 plasmid (transfection control cells) had similar rounded morphology as control vehicle-treated PR-transfected cells. Immunofluorescence staining revealed that expression of E-cadherin, a differentiation marker, was more prominent in progesterone-treated cells. Expression of keratin and vimentin but not ß-catenin was up-regulated in progesterone treated cells when evaluated by immunoblotting. As signal transducers and activators of transcription (STAT) molecules have been implicated in mammary differentiation, we analyzed the expression of Stat 1, 3, 5a, and 5b proteins and found a significant up-regulation of the Stat 5b protein in progesterone-treated cells. We have provided in vitro evidence of the close association of PR with differentiation in breast cancer. It is likely that the Stat 5b protein may play a major role in progesterone-induced differentiation in breast cancer cells.
This article has been cited by other articles:
 |
|
 |
|
  R. P. Carnevale, C. J. Proietti, M. Salatino, A. Urtreger, G. Peluffo, D. P. Edwards, V. Boonyaratanakornkit, E. H. Charreau, E. B. de Kier Joffe, R. Schillaci, et al. Progestin Effects on Breast Cancer Cell Proliferation, Proteases Activation, and in Vivo Development of Metastatic Phenotype All Depend on Progesterone Receptor Capacity to Activate Cytoplasmic Signaling Pathways Mol. Endocrinol., June 1, 2007; 21(6): 1335 - 1358. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Gizard, R. Robillard, B. Gross, O. Barbier, F. Revillion, J.-P. Peyrat, G. Torpier, D. W. Hum, and B. Staels TReP-132 Is a Novel Progesterone Receptor Coactivator Required for the Inhibition of Breast Cancer Cell Growth and Enhancement of Differentiation by Progesterone. Mol. Cell. Biol., October 1, 2006; 26(20): 7632 - 7644. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Proietti, M. Salatino, C. Rosemblit, R. Carnevale, A. Pecci, A. R. Kornblihtt, A. A. Molinolo, I. Frahm, E. H. Charreau, R. Schillaci, et al. Progestins Induce Transcriptional Activation of Signal Transducer and Activator of Transcription 3 (Stat3) via a Jak- and Src-Dependent Mechanism in Breast Cancer Cells Mol. Cell. Biol., June 15, 2005; 25(12): 4826 - 4840. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Palmieri, D. O. Halverson, T. Ouatas, C. E. Horak, M. Salerno, J. Johnson, W. D. Figg, M. Hollingshead, S. Hursting, D. Berrigan, et al. Medroxyprogesterone Acetate Elevation of Nm23-H1 Metastasis Suppressor Expression in Hormone Receptor-Negative Breast Cancer J Natl Cancer Inst, May 4, 2005; 97(9): 632 - 642. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
