Navigation Links
Ovarian cancer advances when genes are silenced
Date:12/13/2010

DURHAM, N.C. There are many mechanisms that alter the activity of genes direct changes to the DNA code like mutations and deletions, or changes that control when genes are switched on and off, called epigenetic means. Tumor-suppressor genes are often inactivated through epigenetics, which provides an opening for the cancerous growth of cells.

Researchers at the Duke Cancer Institute have found evidence of epigenetics at work on a genome-wide scale in cases of ovarian cancer. One major biological signaling pathway in particular was found to contain many genes influenced by DNA methylation a mechanism for turning off genes -- in tumor cells.

The researchers performed a series of studies on cancer cell lines and primary tumor specimens from ovarian cancer patients by comparing the genome-wide gene expression profiles of cells that were treated or mock-treated with drugs that inhibit DNA methylation. From these studies they identified 378 candidate methylated genes. From this group, all 43 of the predicted genes the researchers analyzed showed methylation in ovarian cancers.

"We were very surprised to see that so many of these genes were part of one pathway, the TGF-beta signaling pathway, so we conducted studies to further explore how methylation might have an effect on the pathway," said senior author Susan Murphy, Ph.D., assistant professor in the Division of Gynecologic Oncology in Duke OB-GYN and in the Department of Pathology.

When the researchers treated tumor cells with methylation inhibitors, the TGF-beta pathway showed increased activity. This is an important signaling pathway that directs many processes in cells. A smoothly functioning TGF-beta pathway ensures proper cell growth, cell differentiation, and apoptosis (programmed cell death), and helps prevent tumor formation. When this pathway is deregulated, it can instead help tumors grow and metastasize.

The study showed for the first time that TGF-beta pathway function is regulated through methylation. "This is only one piece of a larger puzzle about the biology of ovarian cancer, but we can say that DNA methylation does have an influence on suppressing TGF-beta pathway signaling, which contributes to ovarian cancer."

In addition, the genes they studied included a cluster of genes that strongly correlated with TGF-beta pathway activity in specimens from older women, which suggested that age-related epigenetic changes can accumulate and may contribute to cancer.

Murphy said two different groups of patients the team identified might need different approaches.

"Some women with ovarian cancer have lower expression of these tumor-suppressing genes and may be amenable to epigenetic therapies that lead to gene reactivation with the caveat that at this point we can't epigenetically reactivate just one gene or a specific group of genes," Murphy said. "Another group of women with ovarian cancer have higher expression of these genes, suggesting it may be possible to specifically inhibit particular components in this pathway to stop tumor development or progression."


'/>"/>

Contact: Mary Jane Gore
mary.gore@duke.edu
919-660-1309
Duke University Medical Center
Source:Eurekalert

Related medicine news :

1. How to make the best decisions when at high risk for breast or ovarian cancer
2. Foster Friess commits up to $50,000 to help TGen fight ovarian cancer
3. Study finds delay in referrals for older women with ovarian cancer
4. Pre-Diagnosis Diet Linked to Ovarian Cancer Survival
5. Only women with Western Swedish breast cancer gene run higher risk of ovarian cancer
6. Ovarian cancer study offers vital clues for new therapies
7. Researchers identify a new breast and ovarian cancer susceptibility gene
8. Study Makes Strides in Understanding Ovarian Cancer
9. PMH cancer researchers link ovarian hormone to breast stem cells growth
10. CA-125 change over time shows promise as screening tool for early detection of ovarian cancer
11. Early Detection of Ovarian Cancer Moves Closer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... (PRWEB) , ... April 28, 2016 , ... ... which is has been collaborating with doctors and hospitals to make transformative changes ... the world’s leading cell therapy minds this week in discussing breakthroughs in cellular ...
(Date:4/28/2016)... ... ... reminds us that May is National Stroke Awareness Month. According to the Centers for ... the United States; someone has one every 40 seconds. Annually, almost 800,000 strokes occur ... A stroke is when blood flow to the brain is blocked or when a ...
(Date:4/28/2016)... Philadelphia, PA (PRWEB) , ... April 28, 2016 ... ... Barbara Browne, M.D. has been named a Top Doc in Physical Medicine and ... in conjunction with Castle Connolly Medical, Ltd. by randomly surveying physicians and medical ...
(Date:4/28/2016)... MO (PRWEB) , ... April 28, 2016 , ... Denise McCormick Baich had written poetry ... 2009 the poetry arrived again much like a tsunami and took on a more spiritual ... to her encouraged her to do more with it than just file it away. Friends ...
(Date:4/28/2016)... ... April 28, 2016 , ... Prescription ... co-operative bankruptcy to receive their prescription medications through America’s fastest-growing pharmacy program. ... medications from over 180 American pharmaceutical companies for $35 per month, per ...
Breaking Medicine News(10 mins):
(Date:4/28/2016)... 28, 2016  ValGenesis, Inc., the market ... (VLMS) today announced that a prominent world ... of chronic kidney failure has selected ValGenesis ... corporate validation process. The global medical device ... to manage their validation processes electronically. Upon ...
(Date:4/27/2016)... April 27, 2016  Hologic, Inc. (Nasdaq: ... results for the fiscal second quarter ended March ... of $0.24 increased 41.2%, and non-GAAP diluted EPS ... increased 5.8% on a reported basis, and 6.3% ... "We posted another good quarter, highlighted by 14.6% ...
(Date:4/27/2016)... 27, 2016   ... in Recurring Consumable Sales  Clinical sales grow ... Technologies (Euronext: MKEA, OTCQX: MKEAY) inventor of Cellvizio®, the ... for the first quarter ended March 31, 2016 and ... of its commercial strategy. First Quarter 2016 ...
Breaking Medicine Technology: