UNM Cancer Center researcher looks for genetic markers for ovarian cancer

October 23, 2012, University of New Mexico Cancer Center

Ovarian cancer is a deadly disease. With no overt symptoms and no screening tests to catch it early, ovarian cancer is often detected at stage 3 or later. By then, it can be very aggressive and may have spread beyond the ovaries into other organs. Many women eventually succumb to it; the five-year survival rate for a stage 3 ovarian cancer diagnosis is only 34 percent.

"We're challenged on every front by this cancer," says Linda Cook, PhD, University of New Mexico Professor of Epidemiology and Biostatistics. "It's even challenging to find modifiable risk factors, such as behaviors that people can change." So Dr. Cook will soon examine a unique aspect of the disease using a rare resource. With the support of a large National Institutes of Health multi-year grant, she will study the mitochondrial DNA differences in several hundred women with and without . "Our hypothesis is that we will see differences in the ," explains Dr. Cook. "Our preliminary data suggest that these differences may be related to survival." These genetic differences in the mitochondria could provide the basis for a screening test or possibly even a drug intervention.

Mitochondria are that produce energy for the cell. They have their own set of DNA, referred to as mtDNA, which are passed down solely from the mother in the because from the father carry only . Although composed of the same set of nucleotide bases as nuclear DNA, mtDNA is much more susceptible to mutations. It contains only 16,500 bases while nuclear DNA has over 3 billion bases in each cell; so while nuclear DNA can twist tightly to protect itself from mutations, mtDNA is too short to do so. Nuclear DNA gains additional protection from the surrounding it and by associating with histones and other molecules in the nucleus except when it is being copied or transcribed. But like nuclear DNA, mtDNA has polymorphisms which are the variations in the sequence of the bases between different individuals. Dr. Cook's research will focus on understanding the role mutations and polymorphisms play in ovarian cancer.

To conduct this mtDNA population study, Dr. Cook and her colleagues will use a unique resource they have spent more than a decade to build. The resource is a database of information on over 4,200 Canadian women—almost 1,600 of whom have been diagnosed with ovarian cancer. The database gives Dr. Cook's team access to each woman's blood or saliva samples, tissue samples, medical records, and records from an in-depth interview on lifestyle. The researchers have followed each woman for at least 4 years so they have access to information on lifestyle changes, treatment responses, and cancer survival as well. "Because we're taking a very comprehensive look at ovarian cancer," says Dr. Cook, "we need to consider this multi-layer complexity of data on a single person. We're considering gene-environment interactions, gene-gene interactions, and interactions with treatment, so we've got to have a lot of information from a lot of people." The large number of women in the study gives Dr. Cook's team the ability to find enough people with the same set of interactions so that statistically significant predictions are possible.

The Canadian arm of Dr. Cook's research team will sequence mtDNA from the blood and saliva samples and will analyze the tissue samples. The New Mexico researchers will then use this information along with the other database information in their population analyses. The analyses will search for correlations between mtDNA sequences and incidence of ovarian cancer, type of ovarian cancer, response to treatment, and survival probability. Such correlations strongly suggest genetic markers for the disease, which researchers could then use to create screening protocols and therapies.

Thus, finding sequences that show promise as potential will be crucial to ovarian cancer research. "We can't intervene on any population risk factors and the therapies for ovarian cancer just extend survival. Although we've made progress, ultimately these women are dying of ovarian cancer," says Dr. Cook. "So, if we can discover the basis for a screening test or a therapy that will prevent mortality, it will help. Any information we can get on this cancer will really help."

Explore further: Routine screening for ovarian cancer a failure: study

Related Stories

Routine screening for ovarian cancer a failure: study

September 11, 2012
Routine screening for ovarian cancer is ineffective and at times can do more harm than good, a panel of cancer specialists has concluded.

Faulty gene connected to ovarian cancer risk

August 9, 2011
In a new study published in Nature Genetics researchers say that women who possess a fault in a gene named RAD51D have a greater risk of developing ovarian cancer than women who do not have this fault and tests are expected ...

Unique genetic marker may improve detection of recurrent ovarian cancer

December 7, 2011
Ovarian cancer is a major health concern for women and the identification of sensitive biomarkers for early detection and/or monitoring of disease recurrence is of high clinical relevance.

Recommended for you

Single blood test screens for eight cancer types

January 18, 2018
Johns Hopkins Kimmel Cancer Center researchers developed a single blood test that screens for eight common cancer types and helps identify the location of the cancer.

How cancer metastasis happens: Researchers reveal a key mechanism

January 18, 2018
Cancer metastasis, the migration of cells from a primary tumor to form distant tumors in the body, can be triggered by a chronic leakage of DNA within tumor cells, according to a team led by Weill Cornell Medicine and Memorial ...

The pill lowers ovarian cancer risk, even for smokers

January 18, 2018
(HealthDay)—It's known that use of the birth control pill is tied to lower odds for ovarian cancer, but new research shows the benefit extends to smokers or women who are obese.

These foods may up your odds for colon cancer

January 18, 2018
(HealthDay)—Chowing down on red meat, white bread and sugar-laden drinks might increase your long-term risk of colon cancer, a new study suggests.

Researchers find a way to 'starve' cancer

January 18, 2018
Researchers at Vanderbilt University Medical Center (VUMC) have demonstrated for the first time that it is possible to starve a tumor and stop its growth with a newly discovered small compound that blocks uptake of the vital ...

Modular gene enhancer promotes leukemia and regulates effectiveness of chemotherapy

January 18, 2018
Every day, billions of new blood cells are generated in the bone marrow. The gene Myc is known to play an important role in this process, and is also known to play a role in cancer. Scientists from the German Cancer Research ...

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.