What happens if we start using induced pluripotent stem (iPS) cells clinically in humans?
A cool new paper recently came out that gets us closer to being able to predict an answer.
It’s an important question as iPS cell-derived cellular products are getting closer to clinical use. For example, the first iPS cell-based clinical trial began to enroll patients in Japan last year in a clinical study related to macular degeneration (see my interview with Dr. Masayo Takahashi, who is leading that intriguing study). In addition, other studies of iPS cell-based therapies are planned in the near future in humans.
A new study out in Cell Reports moves the field a step closer to understanding how iPS cells themselves as well as differentiated derivatives might behave in humans.
The study, Hong, et al., was led by Dr. Cynthia Dunbar.
They made iPS cells (aka IPSCs) from nonhuman primates and conducted pre-clinical studies on them based on transplantation.
The naive iPSCs were tumorigenic (see part of Figure 2 from the paper above), but perhaps far less so than expected. It took about ten million or more monkey iPSCs to consistently generate teratoma. While there is a certainly a “group effect” of more cells leading to an overall riper environment for tumorigenesis, it is also likely that this means that it is only the rare monkey iPSC that is tumorigenic. That’s good news!
For another take on this article see a nice piece by Monya Baker.