Telomere Length and Telomerase Activity in Subcutaneous and Visceral Adipose Tissues from Obese and Non-Obese Patients with and without Colorectal Cancer

SIMPLE SUMMARY: The risk associated with obesity for the development of colorectal cancer seems to be well established. However, no biomarkers have been defined that allow the degree of obesity to be related to the clinical evolution of individuals affected by colorectal cancer. With the aim of contributing to the development of this correlation, we carried out a prospective study investigating parameters related to telomere function in the subcutaneous and visceral adipose tissues of a total of 147 subjects affected and not affected by colorectal cancer. Both the relative telomere length and the activity of telomerase in the adipose tissues seem to constitute parameters of interest in the clinical evaluation of individuals with colorectal cancer, which could be also related to the body mass index. ABSTRACT: To investigate the molecular mechanisms that link obesity and colorectal cancer (CRC), we analyzed parameters related to telomere function in subcutaneous and visceral adipose tissues (SAT and VAT), including subjects with and without CRC, who were classified according to their body mass index (BMI). Adipose tissues were obtained from 147 patients who had undergone surgery. A total of 66 cases corresponded to CRC patients, and 81 subjects were not affected by cancer. Relative telomere length was established by qPCR, and telomerase activity was determined by a method based on the telomeric repeat amplification protocol. Our results indicated longer telomeres in patients affected by CRC, both in SAT and VAT, when compared to the group of subjects without CRC. Tumor local invasion was associated with telomere length (TL) in SAT. Considering the BMI values, significant differences were found in the TL of both adipose tissues between subjects affected by CRC and those without cancer. Overweight subjects showed the greatest differences, with longer telomeres in the group of CRC patients, and a higher number of cases with telomerase reactivation in the VAT of subjects without cancer. In conclusion, parameters related to telomere function in adipose tissue could be considered as potential biomarkers in the evaluation of CRC and obesity.