
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Experimental Therapeutics |
Departments of Clinical Research, Ministry of Health (V. C-L. L., S. E. A., M. G-K. T., V. S-W. C.), and General Surgery, Singapore General Hospital (E. H. N., E. H-L. N., G. H. H.), Republic of Singapore 169608
ABSTRACT
Because progesterone exerts its effects mainly via estrogen-dependent progesterone receptor (PgR), the expression of progesterones effects may be overshadowed by the priming effect of estrogen. PgR expression vectors were transfected into estrogen receptor (ER)-
and PgR-negative breast cancer cells MDA-MB-231; thus the functions of progesterone could be studied independent of estrogens and ERs. Eight stable transfectant clones expressing both PgR isoform A and B were studied for their growth response to progesterone and its analogues. Although progesterone had no effect on growth in the control transfectant, the hormone markedly inhibited DNA synthesis and cell growth in all of the PgR-transfectants dose-dependently from 10-1210-6M. This growth inhibition was associated with an arrest of cells in the G0/G1 phase of the cell cycle. Progestins medroxyprogesterone acetate, Org2058, and R5020 also strongly inhibited DNA synthesis, and their doses required for maximal inhibition of 6070% were 10-17M, 10-13M, and 10-7M, respectively. Antiprogestin ZK98299 alone had no effect, but the compound was capable of counteracting the inhibitory effect of progesterone. In contrast, RU486 inhibited DNA synthesis, and it showed no further effects when it was used concurrently with progesterone. These results indicate that progestins are per se antiproliferative via a PgR-mediated mechanism in breast cancer cells. More importantly, we have shown that progestins may exert effective inhibitory control over the cell growth if the PgR expression is reactivated in ER- and PgR-negative breast cancer cells.
This article has been cited by other articles:
![]() |
S. Goldman and E. Shalev Difference in Progesterone-Receptor Isoforms Ratio Between Early and Late First-Trimester Human Trophoblast Is Associated with Differential Cell Invasion and Matrix Metalloproteinase 2 Expression Biol Reprod, January 1, 2006; 74(1): 13 - 22. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z.-Y. Zheng, B.-H. Bay, S.-E. Aw, and V. C-L. Lin A Novel Antiestrogenic Mechanism in Progesterone Receptor-transfected Breast Cancer Cells J. Biol. Chem., April 29, 2005; 280(17): 17480 - 17487. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Sumida, Y. Itahana, H. Hamakawa, and P.-Y. Desprez Reduction of Human Metastatic Breast Cancer Cell Aggressiveness on Introduction of Either Form A or B of the Progesterone Receptor and Then Treatment with Progestins Cancer Res., November 1, 2004; 64(21): 7886 - 7892. [Abstract] [Full Text] [PDF] |
||||
![]() |
Q. Ji, C. Aoyama, Y.-D. Nien, P. I. Liu, P. K. Chen, L. Chang, F. Z. Stanczyk, and A. Stolz Selective Loss of AKR1C1 and AKR1C2 in Breast Cancer and Their Potential Effect on Progesterone Signaling Cancer Res., October 15, 2004; 64(20): 7610 - 7617. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. C. L. Leo, C. Guo, C. T. Woon, S. E. Aw, and V. C. L. Lin Glucocorticoid and Mineralocorticoid Cross-Talk with Progesterone Receptor to Induce Focal Adhesion and Growth Inhibition in Breast Cancer Cells Endocrinology, March 1, 2004; 145(3): 1314 - 1321. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. C. L. Lin, C. T. Woon, S. E. Aw, and C. Guo Distinct Molecular Pathways Mediate Progesterone-Induced Growth Inhibition And Focal Adhesion Endocrinology, December 1, 2003; 144(12): 5650 - 5657. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. C.-L. Lin, R. Jin, P.-H. Tan, S.-E. Aw, C.-T. Woon, and B.-H. Bay Progesterone Induces Cellular Differentiation in MDA-MB-231 Breast Cancer Cells Transfected with Progesterone Receptor Complementary DNA Am. J. Pathol., June 1, 2003; 162(6): 1781 - 1787. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Cui, P. Zhang, W. Deng, S. Oesterreich, Y. Lu, G. B. Mills, and A. V. Lee Insulin-Like Growth Factor-I Inhibits Progesterone Receptor Expression in Breast Cancer Cells via the Phosphatidylinositol 3-Kinase/Akt/Mammalian Target of Rapamycin Pathway: Progesterone Receptor as a Potential Indicator of Growth Factor Activity in Breast Cancer Mol. Endocrinol., April 1, 2003; 17(4): 575 - 588. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. M. Ahola, N. Alkio, T. Manninen, and T. Ylikomi Progestin and G Protein-Coupled Receptor 30 Inhibit Mitogen-Activated Protein Kinase Activity in MCF-7 Breast Cancer Cells Endocrinology, December 1, 2002; 143(12): 4620 - 4626. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. C. L. Lin, A. S. Eng, N. E. Hen, E. H. L. Ng, and S. H. Chowdhury Effect of Progesterone on the Invasive Properties and Tumor Growth of Progesterone Receptor-transfected Breast Cancer Cells MDA-MB-231 Clin. Cancer Res., September 1, 2001; 7(9): 2880 - 2886. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. C.-L. Lin, E. H. Ng, S. E. Aw, M. G.-K. Tan, E. H.-L. Ng, and B. H. Bay Progesterone Induces Focal Adhesion in Breast Cancer Cells MDA-MB-231 Transfected with Progesterone Receptor Complementary DNA Mol. Endocrinol., March 1, 2000; 14(3): 348 - 358. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Cancer Research | Clinical Cancer Research |
| Cancer Epidemiology Biomarkers & Prevention | Molecular Cancer Therapeutics |
| Molecular Cancer Research | Cancer Prevention Research |
| Cancer Prevention Journals Portal | Cancer Reviews Online |
| Annual Meeting Education Book | Meeting Abstracts Online |