Featured Research

from universities, journals, and other organizations

Known Tumor Suppressor Gene May Play A Role In Breast Cancer

Date:
July 22, 1997
Source:
University Of California, Santa Cruz
Summary:
A gene linked to the most common abdominal cancer in children also may contribute to the development of breast cancer, according to a study at the University of California, Santa Cruz, and Oregon Health Sciences University.

July 22, 1997Contacts:Robert Irion, UC Santa Cruz: (408) 459-2495; irion@ua.ucsc.eduJulianne Remington, OHSU: (503) 494-8231; remingju@ohsu.edu

KNOWN TUMOR SUPPRESSOR GENE MAY PLAY A ROLE INBREAST CANCER

FOR IMMEDIATE RELEASE

SANTA CRUZ, CA--A gene linked to the most common abdominal cancer in children also may contribute to the development of breast cancer, according to a study at the University of California, Santa Cruz, and Oregon Health Sciences University.

A team led by UC Santa Cruz biologist Gary Silberstein found evidence that a gene called WT1, which prevents abnormal cell division in the kidney, also is active in healthy breast tissues. However, the gene was silent, or nearly so, in two-thirds of the cancerous breast tissues examined by the team. These tissues included tumors in their earliest stages of growth--just a few cells beginning to run amok.

The study is the first to make a connection between breast cancer and WT1, so named because of its role in the childhood kidney cancer called Wilm's tumor. The team published its research today (July 22) in the Proceedings of the National Academy of Sciences.

"It is not inconceivable that the loss of WT1 function is an early event in the progression to breast cancer," said Silberstein, an associate research biologist at UCSC. "This really is a brand-new finding, a once-in-a-lifetime connection that should open new avenues of breast-cancer research."

Silberstein emphasized that the research will not lead to new medical or preventive treatments in the near future. However, by shedding light on the cellular machinations of diseased breasts, it may give researchers a new strategy as they attempt to devise "gene therapy" approaches to restore the normal functions of genes that stunt the growth of tumors.

Silberstein led the study in the laboratory of Charles Daniel, research professor of biology at UCSC. Other coauthors included Charles T. Roberts, Jr., professor of pediatrics at Oregon Health Sciences University and an expert on Wilm's tumor, and UCSC researchers Katharine Van Horn and Phyllis Strickland.

The scientists received samples of both healthy and diseased breast tissues via Daniel's ongoing collaboration with physicians at Dominican Santa Cruz Hospital, most notably pathologist Dr. Kelly O'Keefe and surgeon Dr. John Snyder. All tissues were obtained with the informed consent of patients. Other samples came from the University of Michigan's Breast Tissue Bank.

WT1, it appears, is among a chain of genes that helps govern the production of important hormones, called growth factors, in both the kidney and the breast. The growth factors are part of a fine-tuned hormonal system of checks and balances that controls the extent to which cells proliferate. WT1's key targets in the cell are hormones known as insulin-like growth factors (IGFs) and transforming growth factor beta (TGF-b). Research in the labs of Daniel and others has shown that both IGFs and TGF-b are crucial to regulating growth in mammary glands.

When WT1 does its job, it instructs the cell to churn out proteins that manage the amount of IGFs and TGF-b. "WT1 essentially is a middle-management gene," Silberstein said. "It's expressed in an exceedingly complex way--it's basically four genes in one. But there is a direct connection between WT1 and factors that control the growth of breast tissues."

The researchers examined normal tissues from the breasts of six patients who had undergone breast-reduction surgery at Dominican Hospital. The WT1 protein was present in cells from all of these patients, indicating that the gene was active and functioning properly.

Then, the team looked at tissues excised from 21 breast-cancer patients, ranging in age from 29 to 88 years. In 40 percent of all the tumors studied, the researchers could not detect the WT1 protein--the gene, for unknown reasons, had malfunctioned or fallen silent. In another 28 percent of the tumors, most of the cells lacked the WT1 protein.

"The story is complex, because it has been difficult to find a single molecular or genetic defect that is common to all the various forms of breast tumors," said Roberts, who directs the Doernbecher Pediatric Research Laboratories at OHSU. "Finding abnormal WT1 activity in several types of breast cancer suggests that defects in WT1 action may underlie many forms of breast cancer."

Curiously, the WTI gene was active in a highly malignant subset of advanced breast tumors, called estrogen receptor-negative tumors. However, the researchers also detected another well-known tumor suppressor gene, called p53, in these malignant cells. Those two genes can interact, so p53 may interfere with WT1's normal function.

There is no evidence of a mutation in the WT1 gene, Silberstein said, so WT1 would not be a factor in hereditary breast cancers. No relationship is yet evident between the WT1 gene and the previously discovered BRCA I and II genes, which play a role in hereditary forms of breast cancer. Those cases comprise 5 to 10 percent of all breast cancers.

Silberstein, Daniel, and their UCSC colleagues are completing a study of the developmental regulation of WT1 in the mammary glands of mice. Early results support the findings from human tissues: the gene's products are absent in precancerous tissues but present in more mature tumors.

The research was supported by grants from the National Institutes of Health to the laboratories of both Daniel and Roberts.

#####

Editor's notes: You may reach the principal researchers as follows:Gary Silberstein: (408) 459-4428 or silberstein@biology.ucsc.eduCharles Roberts: (503) 494-4307 or robertsc@ohsu.eduCharles Daniel: (408) 459-4171 or daniel@darwin.ucsc.edu


Story Source:

The above story is based on materials provided by University Of California, Santa Cruz. Note: Materials may be edited for content and length.


Cite This Page:

University Of California, Santa Cruz. "Known Tumor Suppressor Gene May Play A Role In Breast Cancer." ScienceDaily. ScienceDaily, 22 July 1997. <www.sciencedaily.com/releases/1997/07/970722172957.htm>.
University Of California, Santa Cruz. (1997, July 22). Known Tumor Suppressor Gene May Play A Role In Breast Cancer. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/1997/07/970722172957.htm
University Of California, Santa Cruz. "Known Tumor Suppressor Gene May Play A Role In Breast Cancer." ScienceDaily. www.sciencedaily.com/releases/1997/07/970722172957.htm (accessed August 1, 2014).

Share This




More Health & Medicine News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Republicans Vote to Sue Obama Over Healthcare Law

House Republicans Vote to Sue Obama Over Healthcare Law

Reuters - US Online Video (July 31, 2014) The Republican-led House of Representatives votes to sue President Obama, accusing him of overstepping his executive authority in making changes to the Affordable Care Act. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Despite Health Questions, E-Cigs Are Beneficial: Study

Despite Health Questions, E-Cigs Are Beneficial: Study

Newsy (July 31, 2014) Citing 81 previous studies, new research out of London suggests the benefits of smoking e-cigarettes instead of regular ones outweighs the risks. Video provided by Newsy
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
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:
from the past week

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