UNM Cancer Center researcher looks for genetic markers for ovarian cancer

October 23, 2012

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

Scientists develop blood test that spots tumor-derived DNA in people with early-stage cancers

August 16, 2017
In a bid to detect cancers early and in a noninvasive way, scientists at the Johns Hopkins Kimmel Cancer Center report they have developed a test that spots tiny amounts of cancer-specific DNA in blood and have used it to ...

Toxic formaldehyde is produced inside our own cells, scientists discover

August 16, 2017
New research has revealed that some of the toxin formaldehyde in our bodies does not come from our environment - it is a by-product of an essential reaction inside our own cells. This could provide new targets for developing ...

Cell cycle-blocking drugs can shrink tumors by enlisting immune system in attack on cancer

August 16, 2017
In the brief time that drugs known as CDK4/6 inhibitors have been approved for the treatment of metastatic breast cancer, doctors have made a startling observation: in certain patients, the drugs—designed to halt cancer ...

Researchers find 'switch' that turns on immune cells' tumor-killing ability

August 16, 2017
Molecular biologists led by Leonid Pobezinsky and his wife and research collaborator Elena Pobezinskaya at the University of Massachusetts Amherst have published results that for the first time show how a microRNA molecule ...

Popular immunotherapy target turns out to have a surprising buddy

August 16, 2017
The majority of current cancer immunotherapies focus on PD-L1. This well studied protein turns out to be controlled by a partner, CMTM6, a previously unexplored molecule that is now suddenly also a potential therapeutic target. ...

A metabolic treatment for pancreatic cancer?

August 15, 2017
Pancreatic cancer is now the third leading cause of cancer mortality. Its incidence is increasing in parallel with the population increase in obesity, and its five-year survival rate still hovers at just 8 to 9 percent. 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.