In colon cancer, normal colon tissue and blood cells have altered telomere lengths

Abstract

Background: Telomere length (TL) shortened occurs in colorectal carcinogenetic process. Our objective is to determine if it is only a local fact or there are alterations in normal colon cells and in other body cells. Methods: TL of tumoral and normal mucosa and leukocytes of 40 patients operated of colorectal cancer (CRC) and 40 control patients with normal colonoscopy were measured by Southern-blot. Groups were matched by the same localization as tumors, sex, and age. Results: In CRC patients, TRFL (Telomere Repeat Factor Length) leukocytes mean was 8.84 kpb, normal colonic mucosa 7.97 kpb, and tumoral mucosa 7.33 kpb (P<0.001). In the 40 normal control patients, mean TRFL of colonic mucosa was 7.76 kpb, while in blood cells was 7.01 kpb (P<0.001). We observed an inverse correlation between leukocytes TRFL and age (r2=0.17, P=0.008). Mucosa TRFL correlates significantly with patient"s age (r2=0.138, P=0.018). TRFL of controls colonic mucosa correlates with TRFL of their blood cells (r2=0.354, P<0.001). Conclusions: Normal colonic mucosa and leukocytes in CCR patients presents telomere altered in respect to normal patients. Telomere length in normal leukocytes could be an initial marker for colorectal cancer.