Stem cells in the jaw at the heart of debilitating bony growths

Our grantee Songtao Shi at the University of Southern California has discovered how stem cells in the jaw give rise to growths that enlarge the jaw and often require major surgery to remove. These growths are called ossifying fibromas.

Like so many early stage discoveries, his work doesn’t so far treat the growths, but it does show for the first time how the growths form and gives scientists an idea of where to start looking for therapies. The work was published November 7 in Cell Stem Cell.

A press release from USC quotes Shi:

“The only treatment option for ossifying fibromas is surgical, which leads to major loss of vital tissues and challenging post-surgical reconstruction,” Shi says. “Quality of life is largely compromised. Thus, there is an urgent need to understand the underlying mechanism by which stem cells may contribute to the pathophysiology of orofacial benign tumors and to develop target-specific treatment.”

What Shi and his colleagues found is that normal stem cells in the jaw bone, called mesenchymal stem cells, sometimes start producing too much of a particular protein (this protein goes by the name TGF-b). When that happens, the cells start producing extra copies of themselves rather than maintaining the bone. That’s what causes the ossifying fibromas.

In a lab dish, the group blocked the cells from making that excess protein and in response, the cells went back to behaving more normally.

In the story from USC, Shi says the group is now looking at ways to block the extra production of TGF-b in ossifying fibromas as a way of treating the growths without surgery.

Shi has a New Faculty Award from CIRM that is focused on using mesenchymal stem cells as a way treating this and other diseases of the jaw. He describes this work in a short video.

Amy Adams

Haiyan Qin, Cunye Qu, Takayoshi Yamaza, Ruili Yang, Xia Lin, Xue-Yan Duan, Kentaro Akiyama, Yi Liu, Qunzhou Zhang, Chider Chen, Yibu Chen, Hank Heng Qi, Xin-Hua Feng, Anh D. Le, Songtao Shi (2013). Ossifying Fibroma Tumor Stem Cells Are Maintained by Epigenetic Regulation of a TSP1/TGF-β/SMAD3 Autocrine Loop Cell Stem Cell DOI: 10.1016/j.stem.2013.08.010