A MicroRNA Regulates the Mechanism That Prevents Osteoporosis and Bone Metastasis

To this end, they used mouse models that either underexpressed or overexpressed miR-34a.

They reported in the June 25, 2014, online edition of the journal Nature that miR-34a-overexpressing transgenic mice exhibited lower bone resorption and higher bone mass. Conversely, miR-34a knockout and heterozygous mice exhibited elevated bone resorption and reduced bone mass. At the cellular level it was found that miR-34a or molecules that mimicked the function of miR-34a blocked the development of osteoclasts (cells that cause destruction of bone), which make the bone less dense and prone to fracture. High levels of bone destruction and reduced bone density caused by excessive numbers of osteoclasts are characteristic of osteoporosis.

The investigators pointed out that the mechanisms involved in development of osteoporosis were similar to those that allow certain cancers to metastasize into bone tissue.

“This new finding may lead to the development of miR-34a mimics as a new and better treatment for osteoporosis and cancers that metastasize to the bone,” said senior author Dr. Yihong Wan, assistant professor of pharmacology at the University of Texas Southwestern Medical Center. “Interestingly, the mouse miR-34a is identical to that in humans, which means that our findings may apply to humans as well.”

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University of Texas Southwestern Medical Center