Featured Research

from universities, journals, and other organizations

Study Examines Relationship Of Vitamin A Pathway To Breast Tumor Progression

Date:
January 14, 2005
Source:
Journal Of The National Cancer Institute
Summary:
Reduced expression of a protein that regulates the metabolism of vitamin A may contribute to tumor progression in breast cancer, according to a new study in the January 5 issue of the Journal of the National Cancer Institute. The study raises the possibility that this vitamin A pathway is a potential target for breast cancer prevention.

Reduced expression of a protein that regulates the metabolism of vitamin A may contribute to tumor progression in breast cancer, according to a new study in the January 5 issue of the Journal of the National Cancer Institute. The study raises the possibility that this vitamin A pathway is a potential target for breast cancer prevention.

Related Articles


Defects in vitamin A, or retinol, bioactivity may be a possible contributor to human carcinogenesis because vitamin A is required for activation of the retinoic acid receptor (RAR), which induces differentiation of adult epithelial cells. One of the characteristics of epithelial cancers is the loss of differentiated attributes. It has been hypothesized that vitamin A bioactivity in cancer cells may be compromised at the level of retinol metabolism, which is regulated by a number of proteins, including cellular retinol-binding protein I (CRBP-I). A study of CRBP-I in mice demonstrated that the protein plays an essential role in vitamin A storage. In addition, CRBP-I expression is down-regulated in about a quarter of human breast cancers. However, it is not known if reduced CRBP-I function compromises vitamin A bioactivity and, if so, whether such a reduction in function would lead to a loss of differentiation and tumor progression.

To determine whether there is a link between retinol storage, RAR activation, and CRBP-I function in the development of breast cancer, Eduardo F. Farias, Ph.D., of Mount Sinai School of Medicine in New York, and colleagues studied RAR activity, retinol storage, CRBP-I localization, and cell differentiation in human and mouse mammary epithelial cells--which can be used as a model of breast cancer--that expressed normal or mutant CRBP-I.

They found that, in the cells, RAR activation was dependent on CRBP-I-mediated retinol storage, and downregulation of CRBP-I compromised RAR activity, leading to loss of cell differentiation and tumor progression. The authors also observed that the breast tumors derived from these cells that expressed normal CRBP-I regressed, whereas those that did not express CRBP-I continued to grow.

"Our in vivo data suggest that somatic CRBP-I loss of function results in a local deficit in vitamin A storage and metabolism that has profound consequences for the affected tissue, despite presumably normal circulating levels of vitamin A," the authors write. "The consequence of deficient vitamin A storage is a fundamental point that needs to be studied further, but if CRBP-I is indeed essential…, then epidemiologic studies attempting to correlate human vitamin A status with cancer incidence may have been partly misguided."

In an editorial, Reuben Lotan, M.D., of the University of Texas M. D. Anderson Cancer Center in Houston, discusses the role of retinoids in normal development and suggests future research strategies to determine how retinoids may prevent tumor formation and growth of both hormone receptor–positive and –negative breast cancers.

###

Citations:

# Article: Farias EF, Ong DE, Ghyselinck NB, Nakajo S, Kuppumbatti YS, Mira y Lopez R. Cellular Retinol-Binding Protein I, a Regulator of Breast Epithelial Retinoic Acid Receptor Activity, Cell Differentiation, and Tumorigenicity. J Natl Cancer Inst 2004;97:21–29.

# Editorial: Lotan R. A Crucial Role for Cellular Retinol-Binding Protein I in Retinoid Signaling. J Natl Cancer Inst 2004;97:3–5.

Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage. Visit the Journal online at http://jncicancerspectrum.oupjournals.org/.


Story Source:

The above story is based on materials provided by Journal Of The National Cancer Institute. Note: Materials may be edited for content and length.


Cite This Page:

Journal Of The National Cancer Institute. "Study Examines Relationship Of Vitamin A Pathway To Breast Tumor Progression." ScienceDaily. ScienceDaily, 14 January 2005. <www.sciencedaily.com/releases/2005/01/050111122220.htm>.
Journal Of The National Cancer Institute. (2005, January 14). Study Examines Relationship Of Vitamin A Pathway To Breast Tumor Progression. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2005/01/050111122220.htm
Journal Of The National Cancer Institute. "Study Examines Relationship Of Vitamin A Pathway To Breast Tumor Progression." ScienceDaily. www.sciencedaily.com/releases/2005/01/050111122220.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Daily Serving Of Yogurt Could Reduce Risk Of Type 2 Diabetes

Newsy (Nov. 25, 2014) — Need another reason to eat yogurt every day? Researchers now say it could reduce a person's risk of developing type 2 diabetes. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins