A type of normal stem cell fuels ovarian cancer by encouraging cancer stem cells to grow, a new study has found.
Cancer stem cells are the small number of cells in a tumour that drive its growth and spread. Traditional cancer treatments do not kill these cells, which is why cancer treatments often fail.
Researchers at the University of Michigan Comprehensive Cancer Center looked in ovarian tissue at the mesenchymal stem cells, which are normal cells found throughout the body.
These cells can form different specialized cells such as fat, bone or cartilage, and they are known to be helpful with wound healing, which has many scientists conjecturing that they may help combat cancer.
In this study, the researchers observed that mesenchymal stem cells in ovarian tumours were different than mesenchymal stem cells from healthy ovaries.
And in fact, the mesenchymal stem cells in the ovarian tumours were fuelling the cancer.
"Cancer is very good at tricking the mesenchymal stem cells into doing what the cancer likes," study author Ronald Buckanovich, M.D., Ph.D., assistant professor of internal medicine and of obstetrics and gynaecology at the U-M Medical School, said.
"The cancer takes the cells hostage and uses them to promote the cancer's growth," he explained.
They also noticed the cancer-associated mesenchymal stem cells increased tumour size, primarily by increasing the number of cancer stem cells.
At the same time, the researchers saw that a type of protein called BMP2 was prevalent in the cancer-associated mesenchymal stem cells. BMP2 is a so-called master regulatory protein, and is carefully regulated in normal cell function.
The researchers found more than three times the amount of BMP in the cancer-associated mesenchymal stem cells than in the normal ones. When BMP was added to cancer cells, it led to an increase in cancer stem cells.
The researchers then used a known BMP inhibitor called Noggin, and found that Noggin blocked the mesenchymal stem cells from triggering this cancer stem cell growth.
The study has been published online in the Journal of Clinical Investigation.