Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Subtle changes in normal genes implicated in breast cancer

14.07.2005


New search method could aid in the discovery of biomarkers



Using a super-efficient method they invented to search for a type of cancer-related change in all genes of a cell, Dana-Farber Cancer Institute researchers have discovered new evidence about how the "microenvironment" of breast cancers helps drive the cancers’ growth and migration.

The scientists found that non-cancerous cells surrounding young breast cancers -- the microenvironment -- undergo epigenetic modifications. (Epigenetic modifications affect genetic function and are passed along to the cell’s offspring, but they don’t alter a gene’s actual structure or DNA.) The subtly altered gene function causes the microenvironment cells to send signals to the breast tumor cells to grow fast and become more aggressive.


"This is the first demonstration that epigenetic occur in the supportive cells of a tumor, and this further emphasizes that surrounding cells play an active role in cancer formation and growth," says Kornelia Polyak, MD, PhD. "These changes in the microenvironment may occur before breast duct cells undergo genetic changes that cause cancer, thus detecting the epigenetic alterations may be a means of early cancer diagnosis or even predicting cancer risk."

Polyak is senior author of the paper, which was posted this week as an advance online publication on the Nature Genetics web site, http://www.nature.com/ng. The first author of the paper is Min Hu, PhD, of Dana-Farber.

Polyak and her colleagues had previously shown that the genes in the microenvironment surrounding the breast’s milk ducts were overactive, and that they continued to be overactive when their cells reproduced, even though their DNA had not been altered. She suspected that the methylation state of the cells’ DNA was being inherited. A gene’s activity can be regulated by a kind of chemical switch process, methylation, when units called methyl groups are added or removed from the gene’s DNA. The on-off pattern of methylation in a cell’s genes can be passed from one generation to another, even when the DNA remains unchanged. This is an example of an epigenetic modification.

Cancer is often associated with less-than-normal methylation of cells’ DNA. Techniques exist for checking the methylation state of a cell, gene by gene. But Polyak and her colleagues, looking to obtain the methylation pattern of a cell’s entire genome (approximately 20,000-25,000 genes) at once, devised a method called Methylation Specific Digital Karyotyping (MSDK) that can read a cell’s complete methylation profile. Polyak and her colleague obtained a profile of the entire genome in a few weeks, a task that would have taken several weeks to months, if it was even possible, using conventional methods.

Using MSDK to study breast cancer tissue, the scientists tested the epithelial and myoepithelial cells that line the breast ducts, and the surrounding cells, known as stoma, including fibroblasts. They found that in all of these cell types, gene expression was altered by epigenetic methylation changes that were not present in normal breast tissue cells.

Most breast cancers develop in the inner lining of the breast’s milk ducts. Some cancerous lesions remain confined within the ducts for years -- called ductal carcinoma in situ or DCIS. Others become invasive, breaking through the walls of the duct into the breast tissue, and threatening to metastasize throughout the body. In previous work, the Dana-Farber scientists showed that the stromal cells of the microenvironment, while not malignant themselves, can goad the cancer cells within the duct into more aggressive action. This insight, the researchers commented, provide a rationale for future chemotherapy that targets the stromal cells as well as the tumors themselves.

In addition to furthering scientific understanding of how breast cancers grow, the method and the new findings could aid in the discovery of biomarkers, or physical changes that could be used in the early detection of breast cancers before they can be diagnosed by conventional means.

Polyak said that Dana-Farber has filed for a patent on the method and the genes identified as aberrantly methylated in the various cell types, and is working with a company to use it for the development of diagnostic tools for early breast cancer diagnosis.

Bill Schaller | EurekAlert!
Further information:
http://www.dfci.harvard.edu

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Epoxy compound gets a graphene bump

14.11.2018 | Materials Sciences

Microgel powder fights infection and helps wounds heal

14.11.2018 | Health and Medicine

How algae and carbon fibers could sustainably reduce the athmospheric carbon dioxide concentration

14.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>