MicroRNA that blocks bone destruction could offer new therapeutic target for osteoporosis

UT Southwestern cancer researchers have identified a promising molecule that blocks bone destruction and, therefore, could provide a potential therapeutic target for osteoporosis and bone metastases of cancer.

The molecule, miR-34a, belongs to a family of small molecules called microRNAs (miRNAs) that serve as brakes to help regulate how much of a protein is made, which in turn, determines how cells respond.

UT Southwestern researchers found that mice with higher than normal levels of miR-34a had increased and reduced bone breakdown. This outcome is achieved because miR-34a blocks the development of bone-destroying cells called osteoclasts, which make the bone less dense and prone to fracture.

"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 and member of the UT Southwestern Harold C. Simmons Cancer Center.

Her team found that injecting nanoparticles containing an artificial version, or mimic, of miR-34a into a mouse with post-menopausal osteoporosis decreased  bone loss. "Interestingly, the mouse miR-34a is identical to that in humans, which means that our findings may apply to humans as well," said Dr. Wan, Virginia Murchison Linthicum Scholar in Medical Research at UT Southwestern.

The study is published online in the journal Nature.

High levels of and reduced bone density caused by excessive osteoclasts are characteristic of osteoporosis, a common bone disease in which bones become fragile and susceptible to fracture. This condition disproportionately affects seniors and women, and leads to more than 1.5 million fractures annually.

miR-34a could have an additional therapeutic application, offering protection from in a variety of cancers, Dr. Wan noted. Bone metastases happen when cells travel from the primary tumor site to the bone, establishing a new cancer location. Researchers saw that injecting the miR-34a mimic in mice could prevent the metastasis of breast and skin cancer cells specifically to bone, mainly by disarming the metastatic niche in bone.

Co-author Dr. Joshua Mendell, Professor of Molecular Biology at UT Southwestern and member of the UT Southwestern Harold C. Simmons Cancer Center, noted that his laboratory previously showed that miR-34a can directly suppress the growth of .

 "We were very excited to see, through this collaborative work with Dr. Wan's group, that miR-34a can also suppress metastasis.  Thus, miR-34a-based therapy could provide multiple benefits for cancer patients," said Dr. Mendell, CPRIT Scholar in Cancer Research. CPRIT is the Cancer Prevention and Research Institute of Texas, which provides voter-approved state funds for groundbreaking cancer research and prevention programs and services in Texas.

add to favorites email to friend print save as pdf

Related Stories

Inflammation mobilizes tumor cells

Mar 19, 2014

Ludwig Maximilian University of Munich researchers have discovered a novel feedback mechanism that provides a mechanistic link between chronic inflammation and carcinogenesis.

Common cancer gene sends death order to tiny killer

May 31, 2007

Scientists at Johns Hopkins have discovered one way the p53 gene does what it's known for—stopping the colon cancer cells. Their report will be published in the June 8 issue of Molecular Cell.

Recommended for you

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.