Novel target found for detecting ovarian cancer in blood.

2004 OCT 7 - (NewsRx.com & NewsRx.net) -- Scientists have discovered a new way to detect ovarian cancer in the blood.

Reporting in the September 15, 2004, issue of Cancer Research, Fox Chase Cancer Center, Philadelphia, researchers explain that the new method targets hypermethylation, one mechanism used by cancer cells to turn off genes that protect against tumor development.

When these tumor-suppressor genes are inactivated by hypermethylation, they cannot do their job, which then allows cancer cells to develop. This research marks the first time hypermethylation has been examined for the detection of ovarian cancer.

Fox Chase molecular biologist Paul Cairns, PhD, and his colleagues tested for hypermethylation of BRCA1 and RASSF1A, two genes strongly associated with ovarian cancer.

"In normal cells, BRCA1 and RASSF1A are unmethylated, meaning they are able to do their job. We found these genes to be frequently hypermethylated in the blood and peritoneal fluid from patients with ovarian cancer," explained Cairns.

Tumor samples, preoperative blood, and peritoneal fluid DNA were obtained and matched from 50 patients with ovarian or primary peritoneal cancer. The blood from 20 healthy age-matched women, normal ovary tissue from 10 women, and tissue, blood, and peritoneal fluid from 10 women with benign ovarian cysts were used for controls.

Thirty-four of the 50 tumors (68%) showed hypermethylation of one or both genes. The remaining 16 tumor samples, which did not show hypermethylation for RASSF1A or BRCA1, had hypermethylated forms of other tumor-suppressor genes: APC, p14, p16, and DAP (death-associated protein-kinases), which provided a target for screening.