Researchers Combat Tumors from Stem Cell Therapy

Pluripotent stem cells are cells that can grow into any tissue. The ability to turn into any type of cell makes pluripotent stem cells a promising treatment for any number of disorders. However, this ability to differentiate into anything also comes with a dangerous side effect: The cells that don’t turn into the desired tissue can instead form dangerous tumors called teratomas. However, researchers have now demonstrated a method to weed out the dangerous teratoma forming cells from the beneficial stem cells.

Led by Micha Drukker, a team of researchers from Stanford University School of Medicine developed a new antibody that can identify the cells that don’t differentiate into the needed tissue before they are transplanted into a patient. The researchers accomplished this by targeting pluripotency surface markers (PSMs,) which are changes within a cell that signify which type of cell it will become. The researchers targeted these specific cellular landmarks by developing antibodies that could seek out cells that did not differentiate.

i09 quotes Drukker saying:

“Commonly used differentiation protocols for embryonic stem and iPS cells often give rise to mixed cultures of cells. Because even a single undifferentiated cell harbors the ability to become a teratoma, we sought to develop a way to remove these cells before transplantation.”

One of the antibodies the researchers created to identify the teratoma cells was successful at finding a PSM called H type-1 glycan. This PSM was found only on cells that had not differentiated. The antibody attracted to the PSM was named anti-stage-specific embryonic antigen 5 (anti-SSEA-5.) This was the most effective combination of PSM and antibody for finding potential teratomas.

By using this targeted anti-SSEA-5 antibody with the PSM to identify which cells were potential teratomas, the researchers were able to eliminate them from a batch of transplant-ready cells so that the dangerous cells would never even have an opportunity to take hold.

Stem cell based therapies have made tremendous advances in the last few years, and while there is still more research to be done before any new practice or technique becomes adopted, it would seem as though this research clears an important hurdle toward the widespread use of stem cells. The research was published in the journal Nature Biotechnology.

(via i09, image via NCTimes)