BEIJING, Dec. 18 (Xinhuanet) -- U.S. researchers found that high levels of two enzymes in ovarian cancer tissue are associated with survival that is nearly five times longer than the survival with lower levels, according to media reports Thursday.

    The research found that high levels of the enzymes -- Dicer and Drosha, crucial for types of microRNA interference, which cells use to shut down genes-- had an average survival of 11 years compared with just over 2.6 years for those with low levels of both proteins.

    In particular, low levels of protein Dicer predicted poor outcomes.

    The research conducted by K. Sood, M.D., of the University of Texas M.D. Anderson Cancer Center, in Houston, and colleagues analyzed tumor tissues from a cohort of 111 patients, using a quantitative reverse transcriptase-polymerase-chain-reaction assay.

    "In the long run, this kind of a factor may be useful as a prognostic factor," said Sood.

    "Not only does this work provide useful prognostic markers, but also, perhaps these molecular mechanisms predicting outcome are the first steps toward designing strategies to target miRNA-processing mechanisms with the goal of improving outcomes," said Frank Slack and Johanne Weidhass of Yale University in New Haven, Conn.

    About 22,430 new cases of ovarian cancer were diagnosed in the United States in 2007, according to the American Cancer Society.

    (Agencies)