Stem cell propagation fuels cancer risk in different organs

Medical News (research)

The results appear online today in the journal Cell.
 Article: Multi-organ Mapping of Cancer Risk, Liqin Zhu, et al., Cell, doi: 10.1016/j.cell.2016.07.045, published 25 August 2016.

...."The chance accrual of random mistakes in cell DNA likely plays an important role in generating cancer; but whether this has to happen in specific cell types, such as stem cells, and precisely how other factors such as environmental carcinogens contribute to cancer is unclear," said the study's senior author, Richard Gilbertson, M.D., Ph.D., director of the Cancer Research UK Cancer Center at Cambridge University, England, and former St. Jude scientific and Comprehensive Cancer Center director. "Indeed, an argument has raged across the scientific community for some years now. Some say cancer is 'bad luck' because mutations arise by chance in stem cells, while others argue environmental carcinogens are more important. This disagreement has arisen largely from the use of different mathematical models to look at existing human cancer and stem cell data, from which it is extremely difficult to tease out the impact of individual factors. Therefore, we tested these opinions in actual experimental models that looked at the individual components that might drive cancer."......

 The scientists also showed that stem cells in newborn animals are far less likely to undergo malignant transformation than adult stem cells. This finding suggests that stem cells in the newborn are intrinsically resistant to the formation of tumors. "If this biology were to hold true in humans, then it may explain why cancer rates are many-fold lower in children than adults, despite the fact that childhood cancers accrue significant numbers of mutations that alter proteins, and that the growth rates of organs peak in childhood," said Zhu....