Ocker cells shake up skeletal science

A population of versatile stem cells that snap into action after injury may also be the key to preventing and treating certain cancers.


Found in mouse bone marrow, OCRs— pronounced ‘ockers’, and short for osteochondroreticular stem cells—come alive to create bone and cartilage after a fracture. They are a completely different population from the mesenchymal stem cells originally believed to be the origin of all bone, cartilage and fat in the body.

Daniel Worthley (R) and colleagues Francis Lee (L) and Siddhartha Mukherjee from Columbia University Medical Center. Credit: Daniel Worthley
Daniel Worthley (R) and colleagues Francis Lee (L) and Siddhartha Mukherjee from Columbia University Medical Center. Credit: Daniel Worthley

“Until this research, we thought we knew all about bone stem cells,” says Daniel Worthley, who performed the work with collaborators at Irving Cancer Research Center, Columbia University, USA.

“But we found a new target cell to study and potentially use in regenerative medicine for skeletal disease.”

The researchers expect to find that an equivalent population is responsible for human tumours. And the stakes are high: osteosarcoma and chondrosarcoma are cancers found in bones and cartilage, and can be hard to treat. The tumours often affect relatively young patients.

But the implications may be even broader. OCRS are classified as connective tissue stem cells, and the research also identified a similar population of cells in the intestine.

“Like scar tissue, connective tissue surrounds many solid organ cancers, and is believed to be important in supporting cancer growth and spread,” says Daniel.

OCRs are opening up a whole new avenue for understanding cancer origins and growth.

Daniel is now looking further at the importance of connective tissue stem cells as head of the Gastrointestinal Cancer Biology Group at the South Australian Health and Medical Research Institute.

For more information: Gastrointestinal Cancer Biology Group, South Australian Health and Medical Research Centre, Daniel Worthley, Dan.worthley@sahmri.com, www.sahmri.com/our-research/themes/cancer/theme/theme-overview