Pathologic Regeneration

Many tissues of the body are able to regenerate to replace cells that are lost or otherwise damaged. Epithelial tissues routinely regenerate, since they line surfaces of the body that are exposed to the external environment (e.g. skin, oral mucosa, lower gynecological tract) or harsh environments (e.g. gastric mucosa exposed to HCl). Regeneration of tissues requires cell division, and each time a cell divides, there is a risk of erroneous DNA replication. While there are robust, complex pathways within the cell that detect and repair DNA replication errors, excessive regeneration increases the likelihood of a DNA error being missed and passed on to daughter cells. This error may allow for other errors to go unchecked, and over time, the accumulation of these DNA errors may result in a malignancy.