p53 deficiency sensitizes clonogenic cells to irradiation in the large but not the small intestine.

摘要: The role of p53 in the survival irradiated crypts small intestine and three regions large (cecum, mid-colon rectum) was assessed by comparing responses null, heterozygous wild-type mice. There no difference levels crypt between genotypes, although rate cell depletion regeneration null mice appeared slower. In intestine, lowest compared to other particular after high doses. heterozygotes were not significantly different from those Hence greater radioresistance colon than reported previously us others using various mouse strains, may be partly attributable presence p53. This effect is readily explained current knowledge concerning decreased expression gene Bcl2 stem zone intestine. Reduced repair associated with lack a G2-phase checkpoint delay, predominant arrest point for intestinal cells, possible explanation decrease survival.