May 3, 2010 Genes interact in complex networks that govern cellular processes, much like people connect a social network through relationships. Researchers are now discovering how biological networks change and are rewired in cancer. In a study published today in Genome Research (www.genome.org), scientists have analyzed the genetic networks of microRNAs in tumors, shedding light on how interactions go awry in disease.
MicroRNAs (miRNAs) are short RNA molecules encoded by plant, animal, and viral genomes that have garnered significant interest for their ability to regulate gene expression. Many critical biological processes are regulated by miRNAs, and recent evidence has shown that alterations in miRNA expression is involved in human tumor development and metastasis.
Investigations into the role of miRNAs in cancer up until now have largely focused on the function and expression of individual miRNAs, but miRNA function is more complex and interwoven. "MicroRNAs were always considered as singles, generally unrelated to each other in the miRNA world," said Ohio State University researcher Carlo Croce. "We did not know much about how miRNAs cooperate."
Because a single miRNA is likely to regulate many genes, and each target gene may be regulated by more than one miRNA, Croce and an international team of colleagues suggested that in order to capture the complex patterns of miRNA expression in cancer, the system must be thought of as a "social network" that coordinates the delicate balance of gene regulation.
Croce explained that in healthy tissues, miRNAs are connected in networks and different cell types have different network connections. In cancer, it is likely that normal network interactions have become disrupted or rewired, contributing to disease.
The group analyzed patterns of miRNA expression levels in a large set of normal and cancerous tissue samples, mappin
|Contact: Peggy Calicchia|
Cold Spring Harbor Laboratory