Other cancers have been linked to altered microRNA levels, Shaughnessy said, but the microRNA levels are more variable, with some being high and some being low in different diseases.

Researchers will now examine whether the high levels of microRNAs are a factor in causing high-risk multiple myeloma or whether the high-risk multiple myeloma triggers the high levels of microRNAs.

The UAMS researchers also examined the relationship between microRNAs and the gene called EIF2C2 or Argonaute 2. This gene controls the maturation of all microRNAs, Shaughnessy said, and could hold the key to new multiple myeloma treatment.

Shaughnessy's group had previously shown that Argonaute 2 is one of 51 overexpressed genes in high-risk multiple myeloma. The data suggest that elevated expression of Argonaute 2 could be an underlying cause of the widespread overexpression of microRNAs in high-risk multiple myeloma, he said.

"In addition, if the behavior of the microRNAs are driving high-risk disease, which, in turn, is driven by elevated expression of Argonaute 2, then controlling Argonaute 2 expression might be a new treatment strategy for high-risk multiple myeloma," Shaughnessy said.

The researchers reported in the PNAS paper that silencing Argonaute 2 in myeloma cell lines causes cell death. Future research will be aimed at using this information to develop more effective treatments based on more in-depth understanding of the disease.

SOURCE University of Arkansas for Medical Sciences