Featured Research

from universities, journals, and other organizations

New hope for hormone resistant breast cancer

Date:
July 22, 2013
Source:
Garvan Institute of Medical Research
Summary:
A new finding provides fresh hope for the millions of women worldwide with estrogen receptor positive breast cancer. Scientists have shown that a specific change, which occurs when tumors become resistant to anti-estrogen therapy, might make the cancers susceptible to treatment with chemotherapy drugs.

A new finding provides fresh hope for the millions of women worldwide with estrogen receptor positive breast cancer. Australian scientists have shown that a specific change, which occurs when tumours become resistant to anti-estrogen therapy, might make the cancers susceptible to treatment with chemotherapy drugs.

Seventy percent of breast cancer patients have estrogen receptor positive cancer, and most patients respond well to anti-estrogen therapies, for a few years at least. Within 15 years, however, 50% will relapse and eventually die from the disease.

Dr Andrew Stone, Professor Susan Clark and Professor Liz Musgrove, from Sydney's Garvan Institute of Medical Research, in collaboration with scientists from Cardiff University, have demonstrated that the BCL-2 gene becomes epigenetically 'silenced' in resistant tumours. This process is potentially detectable in the blood, providing a diagnostic marker. Their findings are now online in the international journal Molecular Cancer Therapetics.

Epigenetics involves biochemical changes in our cells that directly impact our DNA, making some genes active, while silencing others. Epigenetic events include DNA methylation, when a methyl group -- one carbon atom and three hydrogen atoms -- attaches to a gene, determining the extent to which it is 'switched on' or 'switched off'.

Dr Stone and colleagues have shown in human disease, as well as in several different cell models, that BCL-2 is silenced in estrogen-resistant tumours by DNA methylation.

"The main purpose of the BCL-2 gene is to keep cells alive, so when the gene is silenced, cells become more vulnerable to chemotherapy," said Dr Stone.

"The next step will be to test our findings in clinical studies. We propose that if the BCL-2 gene is silenced, patients with estrogen receptor positive breast cancer would benefit from combination therapy. In other words, tamoxifen could be used in combination with a chemotherapy drug, to kill off vulnerable tumour cells."

"Excitingly, this is something that could be implemented into clinical practice very quickly, since the technology now exists to profile methylation of BCL-2 in all patients -- both estrogen responsive and estrogen resistant patients. In addition, the proposed chemotherapy drugs are already in use."

"If such a test were to be implemented, we believe it could help patients much earlier -- hopefully shutting down tumours at an early stage."

Estrogen is a hormone produced by all women, and drives reproduction, menstruation and menopause. Many breast cells have estrogen receptors on their surface. When one of those cells becomes malignant and starts to multiply, an estrogen receptor positive tumour develops. Typically these tumours are fed by high concentrations of estrogen in the bloodstream, triggered by circumstances such as late first pregnancy, not breastfeeding, or too much body fat.

At present, there are three different therapeutic strategies for estrogen receptor positive breast cancer: blocking the body's production of estrogen with aromatase inhibitors; preventing estrogen from 'binding' to the estrogen receptor by 'binding' the drug tamoxifen instead; and destroying the estrogen receptor completely.

Tamoxifen, now the gold standard treatment, became available in the 1970s.

Endocrine therapies, including tamoxifen, are inexpensive and well-tolerated, and are usually given for 5 years. Over time, however, many tumours become resistant to therapy. When one form of treatment starts to fail, a second is put in place, and then a third. Response times shrink, and tumours start to spread to other parts of the body, usually the brain, lungs, liver and bone.

At this late stage, there is little that can be done to help someone, as the brain, lungs, liver and bone are parts of the body that cannot be biopsied or operated upon.


Story Source:

The above story is based on materials provided by Garvan Institute of Medical Research. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Stone, M. J. Cowley, F. Valdes-Mora, R. A. McCloy, C. M. Sergio, D. Gallego-Ortega, C. E. Caldon, C. J. Ormandy, A. V. Biankin, J. M. Gee, R. I. Nicholson, C. G. Print, S. J. Clark, E. A. Musgrove. BCL-2 hypermethylation is a potential biomarker of sensitivity to anti-mitotic chemotherapy in endocrine-resistant breast cancer.. Molecular Cancer Therapeutics, 2013; DOI: 10.1158/1535-7163.MCT-13-0012

Cite This Page:

Garvan Institute of Medical Research. "New hope for hormone resistant breast cancer." ScienceDaily. ScienceDaily, 22 July 2013. <www.sciencedaily.com/releases/2013/07/130722123122.htm>.
Garvan Institute of Medical Research. (2013, July 22). New hope for hormone resistant breast cancer. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2013/07/130722123122.htm
Garvan Institute of Medical Research. "New hope for hormone resistant breast cancer." ScienceDaily. www.sciencedaily.com/releases/2013/07/130722123122.htm (accessed September 1, 2014).

Share This




More Health & Medicine News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Liberia Continues Fight Against Ebola

Liberia Continues Fight Against Ebola

AFP (Aug. 30, 2014) Authorities in Liberia try to stem the spread of the Ebola epidemic by raising awareness and setting up sanitation units for people to wash their hands. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

California Passes 'yes-Means-Yes' Campus Sexual Assault Bill

Reuters - US Online Video (Aug. 30, 2014) California lawmakers pass a bill requiring universities to adopt "affirmative consent" language in their definitions of consensual sex, part of a nationwide drive to curb sexual assault on campuses. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
New Drug Could Reduce Cardiovascular Deaths

New Drug Could Reduce Cardiovascular Deaths

Newsy (Aug. 30, 2014) The new drug from Novartis could reduce cardiovascular deaths by 20 percent compared to other similar drugs. 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:
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