Skip to main content
  • AACR Publications
    • Cancer Discovery
    • Cancer Epidemiology, Biomarkers & Prevention
    • Cancer Immunology Research
    • Cancer Prevention Research
    • Cancer Research
    • Clinical Cancer Research
    • Molecular Cancer Research
    • Molecular Cancer Therapeutics

  • Register
  • Log in
Advertisement

Main menu

  • Home
  • About
    • The Journal
    • AACR Journals
    • Subscriptions
    • Permissions and Reprints
    • Reviewing
  • Articles
    • OnlineFirst
    • Current Issue
    • Past Issues
    • Focus on Computer Resources
    • 75th Anniversary
    • Meeting Abstracts
  • For Authors
    • Information for Authors
    • Author Services
    • Best of: Author Profiles
    • Submit
  • Alerts
    • Table of Contents
    • OnlineFirst
    • Editors' Picks
    • Citations
    • Author/Keyword
  • News
    • Cancer Discovery News
  • AACR Publications
    • Cancer Discovery
    • Cancer Epidemiology, Biomarkers & Prevention
    • Cancer Immunology Research
    • Cancer Prevention Research
    • Cancer Research
    • Clinical Cancer Research
    • Molecular Cancer Research
    • Molecular Cancer Therapeutics

User menu

  • Register
  • Log in

Search

  • Advanced search
Cancer Research
Cancer Research

Advanced Search

  • Home
  • About
    • The Journal
    • AACR Journals
    • Subscriptions
    • Permissions and Reprints
    • Reviewing
  • Articles
    • OnlineFirst
    • Current Issue
    • Past Issues
    • Focus on Computer Resources
    • 75th Anniversary
    • Meeting Abstracts
  • For Authors
    • Information for Authors
    • Author Services
    • Best of: Author Profiles
    • Submit
  • Alerts
    • Table of Contents
    • OnlineFirst
    • Editors' Picks
    • Citations
    • Author/Keyword
  • News
    • Cancer Discovery News
Cellular and Molecular Biology 49: Signaling in Breast Cancer 2

Inhibition of Tamoxifen-stimulated increase in intracellular Ca2+ and apoptosis by vitamin E in estrogen receptor positive breast cancer cells

Elizabeth A. Peralta, Somaja Louis, Deborah Engle and Gary L. Dunnington
Elizabeth A. Peralta
Southern Illinois University School of Medicine, Springfield, IL
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Somaja Louis
Southern Illinois University School of Medicine, Springfield, IL
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Deborah Engle
Southern Illinois University School of Medicine, Springfield, IL
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Gary L. Dunnington
Southern Illinois University School of Medicine, Springfield, IL
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
DOI:  Published May 2005
  • Article
  • Info & Metrics
Loading
Proc Amer Assoc Cancer Res, Volume 46, 2005

Abstract

3712

Background: In addition to their nuclear function, estrogen receptors in the plasma membrane modulate growth and survival signals in breast cancer cells through activation of second messenger pathways. We investigated the activity at the cell membrane of the selective estrogen receptor modulator, Tamoxifen (TAM), in breast cancer cell lines. Methods: The estrogen-receptor positive (ER+) cell lines MCF-7 and T47D, and the ER(-) cell lines MDA-MB-231 and LNCap (prostate) were tested in normal culture medium (10% FCS), steroid-free medium, and medium with 10 microM vitamin E (alpha-tocopherol, AT). Cells were loaded with the calcium-sensitive dye Fluo 4AM. Fluo-4 was excited at 488 nm and emitted fluorescence was filtered with a 535 ± 25 nm bandpass filter and read into a computer running Scanalytics software (Scanalytics Inc., Fairfax, VA). Changes in the intensity of fluorescence (F/Fo) were determined using fluorescence microscopy (Leica, DMIRE2, Plymouth, MN) and plotted against time to evaluate changes in intracellular calcium levels (Cai) in the presence of TAM and vitamin E plus TAM. For apoptosis testing, MCF-7 cells were incubated in test media containing TAM and vitamin E plus TAM. Apoptosis was quantified by pan-caspase activity (R&D systems) at 2 and 5 hours. Results: Exposure of TAM (20 microM) stimulated a significant increase in Cai in T47D and MCF7 cells. The increase in Cai was abolished by pre-incubation with vitamin E (10 microM) and by flowing vitamin E between TAM exposures. The increase in Cai was also abolished by removing calcium from the bathing medium and was not reconstituted after depleting intracellular stores with thapsigargin. TAM did not stimulate an increase in Cai in ER- negative cell lines MDA-MB-231, LNCap, or MCF-7 cells which were incubated in steroid-free medium for 24 hours. The population of MCF-7 cells with pan-caspase staining at 5 hours decreased from 72% in cells treated with 20 microM TAM alone to 41% in cells treated with TAM plus 10 microM vitamin E. Conclusion: The rapid increase in Cai stimulated by TAM in breast cancer cells is dependent on the presence of estrogen receptors. This increase in Cai is followed by caspase activation and apoptosis. Vitamin E abolishes the increase in Cai and reduces apoptosis in TAM-treated MCF-7 and T47D cells. Block of TAM induced increases in Caiby vitamin E may decrease the apoptotic efficacy of TAM in cancer treatment.

  • American Association for Cancer Research
Previous
Back to top
Cancer Research: 65 (9 Supplement)
May 2005
Volume 65, Issue 9 Supplement
  • Table of Contents
  • Index by Author

Sign up for alerts

Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for sharing this Cancer Research article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Inhibition of Tamoxifen-stimulated increase in intracellular Ca2+ and apoptosis by vitamin E in estrogen receptor positive breast cancer cells
(Your Name) has forwarded a page to you from Cancer Research
(Your Name) thought you would be interested in this article in Cancer Research.
Citation Tools
Inhibition of Tamoxifen-stimulated increase in intracellular Ca2+ and apoptosis by vitamin E in estrogen receptor positive breast cancer cells
Elizabeth A. Peralta, Somaja Louis, Deborah Engle and Gary L. Dunnington
Cancer Res May 1 2005 (65) (9 Supplement) 875;

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Share
Inhibition of Tamoxifen-stimulated increase in intracellular Ca2+ and apoptosis by vitamin E in estrogen receptor positive breast cancer cells
Elizabeth A. Peralta, Somaja Louis, Deborah Engle and Gary L. Dunnington
Cancer Res May 1 2005 (65) (9 Supplement) 875;
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Jump to section

  • Article
  • Info & Metrics
Advertisement

Related Articles

Cited By...

More in this TOC Section

  • Phosphatidylinositol 3-kinase, Akt/protein kinase B and P70S6 kinase gene expression in the MCF10A cell line model of proliferative breast disease
  • Different responses associated with PKC-beta-1 and PKC-epsilon overexpression in normal and tumoral mammary cell lines
  • Identification of anti-hormone induced genes as potential therapeutic targets in breast cancer
Show more Cellular and Molecular Biology 49: Signaling in Breast Cancer 2
  • Home
  • Alerts
  • Feedback
Facebook  Twitter  LinkedIn  YouTube  RSS

Articles

  • Online First
  • Current Issue
  • Past Issues
  • Meeting Abstracts

Info for

  • Authors
  • Subscribers
  • Advertisers
  • Librarians
  • Reviewers

About Cancer Research

  • About the Journal
  • Editorial Board
  • Permissions
  • Submit a Manuscript
AACR logo

Copyright © 2018 by the American Association for Cancer Research.

Cancer Research Online ISSN: 1538-7445
Cancer Research Print ISSN: 0008-5472
Journal of Cancer Research ISSN: 0099-7013
American Journal of Cancer ISSN: 0099-7374

Advertisement