Ovarian cancer biomarkers found

In In The News by Barbara Jacoby

By Bradley J. Fikes

From: utsandiego.com

UC San Diego researchers say they have found a potential new diagnostic for ovarian cancer, one of the most difficult cancers to detect and treat.

The discovery of six isoforms of messenger RNA specific to ovarian cancer could also lead to new therapies, the researchers say in a study published Monday in the Proceedings of the National Academy of Sciences. (If the article is not yet live, please check back later).

Christian L. Barrett was the study’s first author; the senior author was Kelly A Frazer.

Ovarian cancers typically don’t show symptoms until well-established. While most respond to therapy at first, recurrences become progressively more difficult to treat.

Scientists at UCSD School of Medicine and Moores Cancer Center used bioinformatics to screen public genetic databases sponsored by the NIH, eventually finding six mRNA isoforms that were reliably present in 296 ovarian cancer samples but not present in 1,839 normal tissue samples. These molecules are specific enough to be used in a test for the early detection of ovarian cancer, the scientists said.

Moreover, some of the mRNA code for proteins representing potential new therapeutic targets, the paper found.

“We were inspired by many studies aimed at using DNA to detect cancer,” Barrett said in a UCSD press release. “But we wondered if we could instead develop an ovarian cancer detection test based on tumor-specific mRNA that has disseminated from cancer cells to the cervix and can be collected during a routine Pap test.”

The researchers validated their findings by searching for and finding these mRNA isoforms in ovarian cancer cells grown in the lab. They suggest that similar testing could be done for 30 other cancers in which sufficient amounts of mRNA have already detected.

However, more validation will be needed by testing the findings in women, not just lab-grown cells, study co-author Cheryl C. Saenz said in the press release.

“Clinical trials will need to be conducted on women to confirm the presence of these markers in women that we know have cancer, as well as to document the absence of the markers in women that do not have ovarian cancer,” Saenz said.

In addition, study authors said the work was limited by technical difficulties including technical limitations in detecting mRNA isoforms, a shortage of normal control samples and the possibility that metastatic ovarian cancer cells might have different genetics than the original tumor.

The research is an example of how genomic discoveries are made possible by the NIH-supported databases, The Cancer Genome Atlas, or TCGA; and the Genotype-Tissue Expression Project, the authors said in the study paper.

“Both of these programs are multicenter efforts that are generating molecular profiling data at a rate, scale and cost that almost certainly could not be borne by any single entity,” the paper stated.

The research was funded with the help of San Diego philanthropists Iris and Matthew Strauss, who discussed their motivations in the press release.

“We created the Iris and Matthew Strauss Center for Early Detection of Ovarian Cancer in memory of our daughter, Stefanie Dawn Strauss,” said Iris Lynn Strauss. “To further honor our daughter, we provided support for this study in an effort to help other women obtain early detection from this dreadful and deadly disease.”