27 September 2010
ByAppeared in BioNews 577
Scientists from Cancer Research UK, Cambridge have suggested a new model for gut stem cell renewal.
It was thought that gut stem cells could only renew themselves via a process of hierarchical cell division - meaning that only a small population of stem cells are able to give rise to all the different types of cell which make up the gut. These cells were then thought to divide to produce daughter stem cells exhibiting a more limited capacity for transformation into cells of the gut.
This new study shows that gut stem cells are in fact capable of self-renewal through a process where neighbouring cells can divide and replace lost stem cells in a 'one in, one out' system. Therefore, only one population of gut stem cells exists with no hierarchy, and this is able to produce all the different cell types of the gut.
This was in contrast to the previous model, where only a few types of gut stem cell were able to do this via daughter precursor cells.
Dr Doug Winton, lead researcher, said: 'We've shown for the first time how the population of stem cells is maintained in the gut and essentially it is a random process with no predetermined fate for the stem cells'.
Understanding the process is important because the cells of the gut constantly undergo cell division in order to regenerate lost cells. This is made possible by the presence of stem cells which are able to react very quickly to lost cells and replace them accordingly. Problems arising during regeneration can cause uncontrolled division that may lead to bowel cancer.
Commenting on the findings, Dr Lesley Walker from Cancer Research UK said: 'This basic biology research could one day lead to real benefits for patients. Cancer stem cells are more resistant to chemotherapy and radiotherapy than the cells that make up the bulk of a tumour, so understanding more about how they behave could lead to better treatments for bowel cancer'.
These findings were published in the journal Science.