'Obscurins' in breast tissue may help physicians predict and detect breast cancer

March 21, 2012, Federation of American Societies for Experimental Biology

A new discovery published online in The FASEB Journal may lead to a new tool to help physicians assess breast cancer risk as well as diagnose the disease. In the report, researchers from Johns Hopkins University and the University of Maryland, explain how proteins, called "obscurins," once believed to only be in muscle cells, act as "tumor suppressor genes" in the breast. When their expression is lost, or their genes mutated in epithelial cells of the breast, cancer develops. It promises to tell physicians how breast cancer develops and/or how likely it is.

"Our studies on the role of obscurins in the development of breast cancer lay the framework for a series of in-depth investigations aiming to understand how these proteins act to prevent tumor formation," said Aikaterini Kontrogianni-Konstantopoulos, Ph.D., a researcher involved in the work from the Department of Biochemistry and Molecular Biology at the University of Maryland School of Medicine in Baltimore, MD. "It is our hope that our research will provide important new insights into breast tumor biology and ultimately yield new targets for the development of innovative therapeutic strategies."

To make this discovery, Kontrogianni-Konstantopoulos and colleagues used a highly specific antibody probe to detect obscurins in normal and cancerous breast, skin, and . They observed that expressed significantly lower amounts of obscurins compared to normal cells, leading to the hypothesis that loss of obscurins allowed normal cells to become cancerous. The researchers then compared two breast epithelial cell populations: a "normal" one, which expressed obscurins and served as a control, and an "altered" one, which failed to express obscurins through genetic manipulations. Both were treated with a chemical called "etoposide," which causes massive DNA damage and induces cell death. Scientists detected and quantified cell death with a number of different methodologies, and found that etoposide caused a significantly high percentage of cell death in normal cells, but only a very low percentage of cell death in the altered, obscurin-deficient cells. This suggests that the loss of obscurins makes breast epithelial cells more resistant to the natural cell death necessary to prevent damaged cells from transforming into a run-away cancer.

"This study is important for a number of reasons. First, it shows that there is a lot more to obscurins than previously thought, making future research into this family of proteins important. Second, it reveals a previously unknown group of tumor suppressors in the breast that prevent normal cells from becoming cancerous. Finally, it opens doors to new tools to help doctors assess a person's risk for cancer and possibly to diagnose it in the earliest of stages," said Gerald Weissmann, M.D., Editor-in-Chief of The .

Explore further: Knockout of protein prevents colon tumor formation in mice

More information: Nicole A. Perry, Marey Shriver, Marie G. Mameza, Bryan Grabias, Eric Balzer, and Aikaterini Kontrogianni-Konstantopoulos. Loss of giant obscurins promotes breast epithelial cell survival through apoptotic resistance. FASEB J. doi: 10.1096/fj. 12-205419

Related Stories

Knockout of protein prevents colon tumor formation in mice

September 29, 2011
A protein that regulates cell differentiation in normal tissue may play a different role in colon and breast cancer, activating proliferation of damaged cells, according to researchers at the University of Illinois at Chicago ...

Biologists uncover surprising connection between breast cancer cells and surrounding tissue

March 14, 2012
Rensselaer Polytechnic Institute Biologist Lee Ligon has found a previously unknown connection between breast cancer tumor cells and the surrounding healthy tissue. The results provide new information on the earliest stages ...

Recommended for you

Researchers develop a remote-controlled cancer immunotherapy system

January 15, 2018
A team of researchers has developed an ultrasound-based system that can non-invasively and remotely control genetic processes in live immune T cells so that they recognize and kill cancer cells.

Pancreatic tumors may require a one-two-three punch

January 15, 2018
One of the many difficult things about pancreatic cancer is that tumors are resistant to most treatments because of their unique density and cell composition. However, in a new Wilmot Cancer Institute study, scientists discovered ...

New immunotherapy approach boosts body's ability to destroy cancer cells

January 12, 2018
Few cancer treatments are generating more excitement these days than immunotherapy—drugs based on the principle that the immune system can be harnessed to detect and kill cancer cells, much in the same way that it goes ...

Cancer's gene-determined 'immune landscape' dictates progression of prostate tumors

January 12, 2018
The field of immunotherapy - the harnessing of patients' own immune systems to fend off cancer - is revolutionizing cancer treatment today. However, clinical trials often show marked improvements in only small subsets of ...

FDA approves first drug for tumors tied to breast cancer genes

January 12, 2018
(HealthDay)—The U.S. Food and Drug Administration on Friday approved the first drug aimed at treating metastatic breast cancers linked to the BRCA gene mutation.

Breast cancer gene does not boost risk of death: study

January 12, 2018
Young women with the BRCA gene mutation that prompted actress Angelina Jolie's pre-emptive and much-publicised double mastectomy are not more likely to die after a breast cancer diagnosis, scientists said Friday.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.