Effect of tamoxifen and tamoxifen derivatives on the conversion of estrone sulfate to estradiol in the MCF-7 mammary cancer cell line

Cancer Letters
J R Pasqualini, C Gelly


The human mammary cancer cell line MCF-7 in culture was used to study the effect of tamoxifen and its derivatives: 4-hydroxytamoxifen (4-OH-Tam), N-desmethyltamoxifen (Dem-Tam) and cis-tamoxifen (cis-Tam) on the uptake and conversion of [3H]estrone sulfate (3H-E1S) to estradiol (E2). When [3H]-E1S (4 X 10(-9) M) was incubated by itself (control) a great proportion of the radioactivity was found as [3H]E2, predominantly in the nuclear fraction. All of the anti-estrogens (10(-6) M - 10(-5) M) studied decreased the total uptake of radioactivity by the cells by 50-60% and the quantity of E2 formed. The calculated concentrations (in pg/mg DNA +/- S.E.M.) of E2 (cytosol + 0.6 M KCl nuclear extract) with the anti-estrogens at 10(-5) M were as follows: control 56 +/- 3; Tam treated cells 4 +/- 1; + 4-OH-Tam 2 +/- 1; + Dem-Tam 5 +/- 2; + cis-Tam 8 +/- 4. A significant decrease in the concentrations of E2 was also observed in the mitochondria-microsomal fractions after the different treatments. It is suggested that the MCF-7 cells can use estrone-3-sulfate as a source of E2 and that the inhibitory effect of tamoxifen and its derivatives on the conversion of this sulfate to E2 could be involved in the anti-estrogenic process of these trip...Continue Reading


Sep 1, 1978·Cancer Treatment Reviews·H MouridsenL Battersby
Jan 1, 1979·Biochemical Pharmacology·H K AdamJ V Kemp
Jan 1, 1986·Breast Cancer Research and Treatment·J R PasqualiniF Lecerf
Jan 1, 1985·Breast Cancer Research and Treatment·R A HawkinsE Killen
Nov 1, 1973·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·J M FromsonS Bramah
Jul 1, 1984·The Journal of Clinical Endocrinology and Metabolism·S J SantnerR J Santen
May 1, 1984·Molecular and Cellular Endocrinology·S BardonH Rochefort
Feb 1, 1980·Steroids·K D RobertsA Chapdelaine

❮ Previous
Next ❯


Oct 1, 1988·Journal of Steroid Biochemistry·J R PasqualiniN Giambiagi
Jan 1, 1989·Journal of Steroid Biochemistry·J R PasqualiniC Vella
Dec 1, 1989·Journal of Steroid Biochemistry·K NaitohT Nambara
Mar 1, 1995·Steroids·P K LiL Dibbelt
Mar 1, 1992·The Journal of Steroid Biochemistry and Molecular Biology·J R PasqualiniB L Nguyen
May 1, 1993·The Journal of Steroid Biochemistry and Molecular Biology·S J Santner, R J Santen
Mar 1, 1995·The Journal of Steroid Biochemistry and Molecular Biology·K W Selcer, P K Li
May 1, 1995·The Journal of Steroid Biochemistry and Molecular Biology·P E LønningH Adlercreutz
Nov 1, 1995·Critical Reviews in Oncology/hematology·E Lønning, E A Lien
Jun 1, 2001·The Journal of Steroid Biochemistry and Molecular Biology·G S Chetrite, J R Pasqualini
Jul 27, 1999·The Journal of Steroid Biochemistry and Molecular Biology·J R Pasqualini, G S Chetrite
Jun 22, 2000·Gynecological Endocrinology : the Official Journal of the International Society of Gynecological Endocrinology·J R PasqualiniG S Chetrite
Apr 1, 1993·Cancer Treatment Reviews·E Lønning
Jan 1, 1992·European Journal of Cancer : Official Journal for European Organization for Research and Treatment of Cancer (EORTC) [and] European Association for Cancer Research (EACR)·J R Pasqualini
Jan 1, 1990·Acta Oncologica·P E Lønning
May 1, 1991·Cancer·M N KossT O'Leary
Sep 27, 1995·International Journal of Cancer. Journal International Du Cancer·A PurohitM J Reed
Apr 22, 1993·International Journal of Cancer. Journal International Du Cancer·S J SantnerR J Santen
Jun 3, 2004·Biochimica Et Biophysica Acta·Jorge R Pasqualini
Oct 13, 1998·Cancer Treatment Reviews·G Y Locker

❮ Previous
Next ❯

Related Concepts

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.


Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.


Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.