In vivo and in vitro estrogenic and progestagenic actions of Tibolone

Estrogen and progestin combination in hormone replacement therapy (HRT) increases the incidence of breast cancer, but decreases the endometrial cancer risk of unopposed estrogen. Therefore, a SERM such as Tibolone, that delivers the beneficial, but not the adverse side effects, of steroid hormones w...

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Main Authors: ANIL SADARANGANI, ANA MARÍA SALGADO, SUMIE KATO, MAURICIO PINTO, ANDRÉS CARVAJAL, CAROLINA MONSO, GARETH I OWEN, PILAR VIGIL
Format: Article
Language:English
Published: BMC 2005-01-01
Series:Biological Research
Subjects:
Online Access:http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200014
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author ANIL SADARANGANI
ANA MARÍA SALGADO
SUMIE KATO
MAURICIO PINTO
ANDRÉS CARVAJAL
CAROLINA MONSO
GARETH I OWEN
PILAR VIGIL
author_facet ANIL SADARANGANI
ANA MARÍA SALGADO
SUMIE KATO
MAURICIO PINTO
ANDRÉS CARVAJAL
CAROLINA MONSO
GARETH I OWEN
PILAR VIGIL
author_sort ANIL SADARANGANI
collection DOAJ
description Estrogen and progestin combination in hormone replacement therapy (HRT) increases the incidence of breast cancer, but decreases the endometrial cancer risk of unopposed estrogen. Therefore, a SERM such as Tibolone, that delivers the beneficial, but not the adverse side effects, of steroid hormones would be clinically advantageous. However, data from the Million Women Study suggests that Tibolone increases the risk of both breast and endometrial cancer. Herein, we assessed the estrogenic and progestagenic actions of Tibolone using transvaginal sonography studies and an in vitro model of breast (ZR-75, MCF7) and endometrial cancer (Ishikawa). The known cancer associated proteins (ER, EGFR, STAT5, tissue factor and Bcl-xL) were selected for study. Transvaginal sonography demonstrated that postmenopausal women treated with Tibolone displayed a thinner endometrium than in the late proliferative phase, but had a phenotype characteristic of the secretory phase, thus demonstrating the estrogenic and progestagenic actions of this SERM. In vitro, Tibolone acted as an estrogen in downregulating ER and upregulating Bcl-xL, yet as progesterone, increasing STAT5 and tissue factor in breast cancer cells. The increase in tissue factor by Tibolone correlated with its coagulative potential. Interestingly, EGFR was up-regulated by progesterone in the breast and by estrogen in endometrial cells, while Tibolone increased protein levels in both cell types. In conclusion, this study further demonstrates the estrogenic and progestagenic nature of Tibolone. The pattern of regulation of known oncogenes in cells of breast and endometrial origin dictates caution and vigilance in the prescription of Tibolone and subsequent patient monitoring
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spelling doaj.art-f68dde2764764f77b3f8b517ebea6a0f2022-12-21T17:31:25ZengBMCBiological Research0716-97600717-62872005-01-01382-3245258In vivo and in vitro estrogenic and progestagenic actions of TiboloneANIL SADARANGANIANA MARÍA SALGADOSUMIE KATOMAURICIO PINTOANDRÉS CARVAJALCAROLINA MONSOGARETH I OWENPILAR VIGILEstrogen and progestin combination in hormone replacement therapy (HRT) increases the incidence of breast cancer, but decreases the endometrial cancer risk of unopposed estrogen. Therefore, a SERM such as Tibolone, that delivers the beneficial, but not the adverse side effects, of steroid hormones would be clinically advantageous. However, data from the Million Women Study suggests that Tibolone increases the risk of both breast and endometrial cancer. Herein, we assessed the estrogenic and progestagenic actions of Tibolone using transvaginal sonography studies and an in vitro model of breast (ZR-75, MCF7) and endometrial cancer (Ishikawa). The known cancer associated proteins (ER, EGFR, STAT5, tissue factor and Bcl-xL) were selected for study. Transvaginal sonography demonstrated that postmenopausal women treated with Tibolone displayed a thinner endometrium than in the late proliferative phase, but had a phenotype characteristic of the secretory phase, thus demonstrating the estrogenic and progestagenic actions of this SERM. In vitro, Tibolone acted as an estrogen in downregulating ER and upregulating Bcl-xL, yet as progesterone, increasing STAT5 and tissue factor in breast cancer cells. The increase in tissue factor by Tibolone correlated with its coagulative potential. Interestingly, EGFR was up-regulated by progesterone in the breast and by estrogen in endometrial cells, while Tibolone increased protein levels in both cell types. In conclusion, this study further demonstrates the estrogenic and progestagenic nature of Tibolone. The pattern of regulation of known oncogenes in cells of breast and endometrial origin dictates caution and vigilance in the prescription of Tibolone and subsequent patient monitoringhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200014breast/endometrium cancerestrogenicHRTprogestagenic & tibolone
spellingShingle ANIL SADARANGANI
ANA MARÍA SALGADO
SUMIE KATO
MAURICIO PINTO
ANDRÉS CARVAJAL
CAROLINA MONSO
GARETH I OWEN
PILAR VIGIL
In vivo and in vitro estrogenic and progestagenic actions of Tibolone
Biological Research
breast/endometrium cancer
estrogenic
HRT
progestagenic & tibolone
title In vivo and in vitro estrogenic and progestagenic actions of Tibolone
title_full In vivo and in vitro estrogenic and progestagenic actions of Tibolone
title_fullStr In vivo and in vitro estrogenic and progestagenic actions of Tibolone
title_full_unstemmed In vivo and in vitro estrogenic and progestagenic actions of Tibolone
title_short In vivo and in vitro estrogenic and progestagenic actions of Tibolone
title_sort in vivo and in vitro estrogenic and progestagenic actions of tibolone
topic breast/endometrium cancer
estrogenic
HRT
progestagenic & tibolone
url http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200014
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