By Pat Anson, PNN Editor

The discovery of a new type of stem cell could revolutionize the treatment of spine disorders and slow the progression of some cancers, according to a groundbreaking study published in Nature.

Researchers from Hospital for Special Surgery (HSS) and Weill Cornell Medicine say the vertebral stem cells they found in human spines appear to play a key role in spinal health and in the metastasis of cancerous tumors as they spread through the body.

“There are two big takeaway discoveries that were made here. One is that we have discovered a stem cell that forms the spine and maintains the spine throughout life. This cell makes all the other cells that mineralize the spine,” said lead investigator Matthew Greenblatt, MD, associate professor of pathology and laboratory medicine at Weill Cornell Medicine.

“The second discovery here is that we found that this stem cell drives tumors. Breast cancer is what we focused on here, but likely also prostate cancer.”

Cancer experts have long believed that tumors metastasize to other parts of the body simply through blood flow. But Greenblat and his colleagues found that vertebral stem cells essentially attract cancer cells to the spine. That could explain why some cancers are first detected in the spine after they have metastasized from the breast, prostate and lung.

“Because we found that molecular ‘come here’ signal that's made by this spine stem cell, that gives us the ability to block that signal therapeutically. And that's something we're working on to try to prevent or treat established spine metastases,” Greenblatt told PNN.

Boosting Bone Health

Researchers say their discovery could also lead to breakthroughs in spinal health, by giving physicians a way to speed up recovery from spinal injuries and slow the progression of degenerative conditions such as osteoporosis, a disease that makes bones thinner, less dense and more likely to fracture.

For example, someone with degenerative disc disease could have their vertebral stem cells harvested, reproduced in a laboratory, and then reinjected to stimulate the growth of new bone. In animal tests, human vertebral stem cells helped laboratory mice form new bones in their spines.

“We can show that they formed basically little vertebral bones when those patient cells are put into mice, which really tells us that we found the right cell. And we can work with the cell transplant and retain stability to make new bone,” said co-author Sravisht Iyer, MD, a spine surgeon at HSS.

“I think kind of figuring out how to recruit the cells or how to how to encourage them to form more bone is going to be an important area or avenue of investigation for us, as a way to help people and protect people against what is a very morbid condition for them.”

Iyer says early treatment with vertebral stem cells could help someone with osteoporosis or a spine fracture, but wouldn’t necessarily benefit patients suffering from more advanced cases of bone loss.

“By the time people are presenting to us with spine pain, they usually have some element of compressive pathology or a degree of degeneration, which will likely require some intervention, whether that's surgery or epidural injection,” Iyer said.

“Where this work I think can really help push us forward is once you get those at-risk patients, they probably will need a surgery because a lot of degeneration is asymptomatic, and by the time they get to you they probably need something, but maybe you can prevent the second, third or fourth operation or intervention.”

More research and human studies are needed before the stem cells can be used in clinical settings to improve bone health and slow the metastasis of cancer cells. But researchers are excited by what they’ve learn so far.    

“We predict this discovery will lead to the targeting of these cells to disrupt the function and ultimately reduce the spread of cancer to the spine," said Greenblatt.