Navigation Links
RNA snippet suppresses spread of aggressive breast cancer
Date:6/15/2009

CAMBRIDGE, Mass. (June 11, 2009) A low cellular level of a tiny fragment of RNA appears to increase the spread of breast cancer in mouse models of the disease, according to researchers at Whitehead Institute for Biomedical Research.

Measuring levels of this so-called microRNA, which is also associated with metastatic breast cancer in humans, may more accurately predict the likelihood of metastasis (which accounts for 90% of cancer-related deaths) and ultimately help determine patient prognoses.

In the study, whose results are reported in the June 12 issue of Cell, Scott Valastyan, a graduate student in Whitehead Member Robert Weinberg's laboratory, screened patient breast cancer samples for microRNAs with potential roles in metastasis. MicroRNAs are single strands of RNA about 21-23 nucleotides long. Within a cell, a single microRNA can fine-tune the expression of dozens of genes simultaneously. This capability could be particularly important in metastasis, a multi-step process that could be influenced by a single microRNA at several points.

The screened samples were classified as either metastatic cancer or non-metastatic cancer. After analysis, the microRNA miR-31 stood out because of its inverse correlation with metastasis. In samples where a patient's original tumor had not metastasized, the cancer cells retained high levels of the microRNA. But where the tumor had metastasized, the cancer cells came to possess lower levels of miR-31.

The functional role of miR-31 in metastasis regulation was then confirmed in mice. When Valastyan removed miR-31 from normally non-aggressive breast cancer cells and implanted those cells into mice, the cells formed highly aggressive tumors. Mice injected with the cancer cells lacking miR-31 had 6 to 10 times more cancer cells that metastasized to their lungs than did their counterparts implanted with unmodified cancer cells.

To see how increasing miR-31 levels could affect metastasis, Valastyan introduced miR-31 into breast cancer cells that readily metastasize. After injecting these altered cells into mice, the mice had four to 40 times fewer metastases than mice injected with the unaltered cells.

Valastyan says that quantifying miR-31 levels in a patient's cancer cells could one day support a more accurate prognosis. Currently, breast cancers are divided into three major categories, two of which are typically associated with poor prognoses.

"This microRNA seems to be quite unique, in that it seems to provide some prognostic utility across these existing subclassifications [of cancers]," says Valastyan. A better-defined prognosis could help patients determine whether they might benefit from poorly tolerated cancer therapies.

In addition, miR-31 could be a useful target for cancer therapy. Weinberg, who is also a professor of biology at MIT, is cautiously optimistic. "At present, it's quite difficult to inhibit the action or promote the actions of a microRNA in a whole organism," he says, "but in the future, microRNAs like this one might prove to be very important in altering the clinical progression of a tumor or causing it to revert to a more benign state."

This research was supported by the National Institutes of Health (NIH), MIT Ludwig Center for Molecular Oncology, U.S. Department of Defense (DoD), Breast Cancer Research Foundation, Harvard Breast Cancer Specialized Program of Research Excellence (SPORE), and a DoD Breast Cancer Research Program (BCRP) Idea Award.


'/>"/>

Contact: Nicole Giese
giese@wi.mit.edu
617-258-6851
Whitehead Institute for Biomedical Research
Source:Eurekalert

Related medicine news :

1. Protein that suppresses androgen receptors could improve prostate cancer diagnosis, treatment
2. Turmeric extract suppresses fat tissue growth in rodent models
3. Protein switch suppresses skin cancer development
4. Protein suppresses allergic response in mice
5. Guardian Survey Reveals Widespread Lack of Understanding of Health Savings Accounts
6. Drug May Extend Life When Breast Cancer Spreads
7. Spread of Swine Flu in Japan Could Raise WHO Alert to Highest Level
8. Researchers study the human factor in spread of pandemic illness
9. Fiber Technology Products that Help Combat Spread of Superbugs Now Available to the Consumer Market
10. New technique may help detect potential breast cancer spread
11. Genes Linked to Spread of Breast Cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/25/2017)... , ... April 25, 2017 , ... A stressful work ... work can also decrease overall productivity and performance in the workplace. The goal of ... During the last few weeks of April, Clearview Resolution Services will be shutting down ...
(Date:4/25/2017)... ... April 25, 2017 , ... Patients who would like to ... a fraction of the time as traditional braces – Wilckodontics®. Dr. Victoria Chen, ... offers this revolutionary treatment with or without a referral. , Wilckodontics is ...
(Date:4/25/2017)... ... 25, 2017 , ... Saad B. Chaudhary, MD is committed to providing the highest quality of ... I focus on preventative care with all my patients to alleviate possible future issues. I ... free to contact my office and my trained staff will assist you in any way ...
(Date:4/25/2017)... ... April 25, 2017 , ... Amendia, ... continuation of its strategic partnership with and platinum sponsorship of Global Spine Outreach ... safe and effective management of complex spine deformity cases, particularly in children. , ...
(Date:4/24/2017)... ... April 24, 2017 , ... Ridgecrest Herbals makes it a point ... strategies to reduce waste, and support renewable energy. They believe this is a crucial ... to find solutions for health issues, and maintain that destroying the environment in the ...
Breaking Medicine News(10 mins):
(Date:4/20/2017)... , April 20, 2017  CVS Pharmacy, the ... unveiled a new store design to enhance the ... healthier food, health-focused products and expanded beauty selections ... help customers discover new offerings. Together with its ... evolution of the customer experience at CVS Pharmacy.  ...
(Date:4/20/2017)... 2017  AbbVie (NYSE: ABBV), a global biopharmaceutical ... chronic hepatitis C virus (HCV) infected patients with ... compensated cirrhosis (Child-Pugh A) achieved sustained virologic response ... its investigational, pan-genotypic regimen of glecaprevir/pibrentasvir (G/P). These ... 12 weeks of G/P treatment without ribavirin. Patients ...
(Date:4/20/2017)... PARIS , April 20, 2017 ... EyeCET platform, the first non-viral gene expression technology that ... in the eye to address a wide range of ... UK Medicines and Healthcare products Regulatory Agency (MHRA) to ... ...
Breaking Medicine Technology: