Navigation Links
RNA snippet suppresses spread of aggressive breast cancer

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
Whitehead Institute for Biomedical Research

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:
(Date:11/25/2015)... (PRWEB) , ... November 25, 2015 , ... On November ... training center for the Narconon network, announced the release of a new cutting edge ... the Narconon organization has been working with drug- and alcohol-addicted individuals with the purpose ...
(Date:11/25/2015)... , ... November 25, 2015 , ... On November 23rd ... Tri Lite’s personal heating products business. Cozy Products explains what this means ... that fit in well with the Cozy Products business model: to sell personal heaters ...
(Date:11/25/2015)... ALTO, Calif. (PRWEB) , ... November 25, 2015 , ... ... Smart and Beddit Classic sleep tracking systems. The new app features a more intuitive ... see and understand how well you slept. The SleepScore is created by a proprietary ...
(Date:11/25/2015)... ... November 25, 2015 , ... “While riding the bus, I saw a ... “I thought there had to be a convenient and comfortable way to protect them ... enables disabled individuals to safely travel during cold or inclement weather. In doing so, ...
(Date:11/25/2015)... , ... November 25, 2015 , ... ... (PHA) announces the nation’s Periwinkle Pioneers, individuals and groups responsible for advancing care ... disease. The Periwinkle Pioneers, nominated by the public, will receive special recognition throughout ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... , November 26, 2015 ... potential to use SyMRI to find optimal contrast weighting of ... tumor metastases, and has signed a research agreement with SyntheticMR ... the hospital. Using SyMRI, it is possible to generate multiple ... settings after the patient has left, thus making it possible ...
(Date:11/26/2015)... -- 3D bioprinting market is expected to ... report by Grand View Research Inc. Rising prevalence of chronic ... transplantation is expected to boost the market growth, as 3D ... --> 3D bioprinting market is expected to ... report by Grand View Research Inc. Rising prevalence of chronic ...
(Date:11/26/2015)... DUBLIN , November 26, 2015 /PRNewswire/ ... the addition of the "2016 Future ... Drugs of Abuse Testing Market: Supplier Shares, ... report to their offering. --> ... of the "2016 Future Horizons and ...
Breaking Medicine Technology: