The Ohio State University researchers said the small microRNA molecules make might make it possible to identify adult acute-leukemia patients who are likely to respond poorly to therapy.

The scientists examined the levels of microRNAs in leukemia cells from 122 patients with high- and intermediate-risk AML and in normal blood stem cells from 10 healthy donors.

The findings showed both the leukemia and the normal cells had similar kinds of microRNA, but the two groups differed in the levels of microRNAs present. The research also identified two microRNAs present at abnormally high levels that were clearly associated with patient survival.

"If our results are validated by other groups, these two elevated microRNAs can be used to determine which patients require more aggressive treatment," said Dr. Ramiro Garzon. "In addition, they may provide new targets for future therapies -- knocking out these two microRNAs might benefit patients who have a poor prognosis."

The study appears in the online issue of the journal Blood.