Researchers have identified a set of microRNAs (miRNAs) linked with a poor prognosis for colorectal cancers for black and white patients and a set that is associated with poor outcomes only for blacks.

In data presented at the American Association for Cancer Research 101st Annual Meeting 2010, Liselle Bovell, a graduate student working in the laboratory of University of Alabama Associate Professor of Pathology, Upender Manne, said overexpressions of miR-21 and miR-106a are associated with an overall poor prognosis and that overexpressions of miR-181b and miR-203 are associated with poor outcomes in blacks.

"This knowledge gives us solid, prognostic information, so we can better manage patients with these cancers early after diagnosis or surgery," said Bovell.

MiRNAs are a family of small non-coding RNAs that regulate expression of various genes. Bovell said researchers have an increased interest in them because they are small, easy to handle and specific in their functions.

For the current study, Bovell examined a panel of the following microRNAs: miR-20a, miR-21, miR-106a, miR-181b and miR-203 in 104 blacks and 114 whites. All five of these miRNAs had higher levels in colorectal cancers compared with non-cancerous control tissue.

Increased levels of miR-181b and miR-203 were linked with shorter patient survival among blacks, but not whites. For both blacks and whites, increased expressions of miR-21 and miR-106a were linked with poor survival.

Increased expression of miR-20a was not linked with survival in either whites or blacks.

Source: The American Association for Cancer Research