The findings suggest the potential for a specific, single microRNA (miR-34a) to be used as a drug candidate in cancer therapy to increase programmed cell-death (apoptosis) in the context of the potent tumor suppressor p53.
p53 has been widely accepted as a powerful tumor inhibitor that can prevent or slow the spread of cancer cells by facilitating apoptosis. In this study, activation of p53 in-vivo in mice as well as in cultured human cells induced the expression of a specific microRNA (miR-34a).
Based on the likelihood that miR-34a could itself play a role in cellular apoptosis, researchers introduced miR-34a directly into human cancer cell lines to determine its impact on tumor cell behavior.
The results clearly demonstrated that overexpression of miR-34a led to increased cancer cell death as well as promoted other important anti-proliferative activities. The ability of miR-34a to promote apoptosis of cancer cells makes it an attractive candidate tumor suppressor.
The data presented in Molecular Cell is also supported by recent studies (Gaur et at., 2007, Welch et al. 2007) showing that miR-34a is under-expressed in central nervous system tumors.
"This is a groundbreaking study shedding light on the critical role microRNAs play in fighting cancer and highlights their potential to act as novel drug targets", noted Dr. Dalia Cohen, Global Head of Research and Development at Rosetta Genomics.
"By introducing increased amounts of miR-34a into the cell-lines, Rosetta Genomics researchers and the world class team at Weizmann Institute have been able to show that the overexpression of this specific microRNA is directly linked to tumor suppression. Moreover, the results suggest the potential that a synthetic miR-34a-like agent could be used as a cancer therapy. We strongly believe this research continues to validate the opportunities for microRNA-based therapeutics."