Cancer treatment may also help osteoporosis

WASHINGTON (Reuters) - A drug used to treat bone marrow cancer may also help treat osteoporosis by stimulating stem cells, U.S. researchers reported on Friday.

They found that Velcade, made by Millennium Pharmaceuticals Inc to treat multiple myeloma, activated stem cells that differentiate into bone.

Tests in mice showed it apparently helps regenerate bone tissue and be may be a potential treatment for osteoporosis, a team at Massachusetts General Hospital and the Harvard Stem Cell Institute reported in the Journal of Clinical Investigation.

Harvard stem cell expert Dr. David Scadden said scientists have been hoping to find ways to use drugs to stimulate stem cells, which are the body's master cells.

"Stem cell therapies are often thought of as putting new cells into the body, but this study suggests that medications can turn on existing stem cells that reside in the body's tissues, acting as regenerative medicines to enhance the body's own repair mechanisms," Scadden said in a statement.

"Drugs that direct immature cells to become a particular cell type, like in this study, could potentially be very useful."

Velcade, known generically as bortezamib, stimulated mesenchymal stem cells, the researchers found. These cells develop into bone-building osteoblasts and several other types of cells including cartilage, fat, skin and muscle.

Tests in mice showed it increases the activity of osteoblasts, and when used in a mouse with osteoporosis it significantly improved bone formation and density.

"If the paradigm displayed in this study holds true for other tissues, we may have options for repairing and regenerating sites affected by injury or disease with medications -- that would be pretty exciting." Scadden said.

(Reporting by Maggie Fox; editing by Will Dunham)