ADIPOSE TISSUE AND ITS ROLE IN MICROENVIRONMENT OF THE COLORECTAL ADENOCARCINOMA CANCER CELL

Introduction. The mechanisms of adipose-tissue’s influence on tumor progression has been studied a lot, but the way of interaction of adipocytes with tumor cells have not been well defined until now. Objective. The aim of this study was to evaluate the mechanisms of adipocytes and tumor cells interaction under the influence of radiation and chemo-radiation therapy in locally advanced rectal cancer (LARC) patients. Material and methods. A prospective randomized single-center study was conducted. It involved 110 patients with LARC and pre-obesity. The patients were randomized into a main group A (radiation therapy and oxaliplatin-based chemotherapy) and a comparison group B (radiation therapy and fluoropyrimidine-based mono-chemotherapy). Superoxide free radicals and NO levels generated by mitochondria of adipocytes were evaluated In both groups’. Also, there was estimated the indices of MMP-2, MMP-9, 8-oxoG, and free fatty acids (FFA) level. Results and discussion. Level of superoxide radicals in tumor-adjacent adipose tissue was 0.58±0.15 (main group) and 0.70±0.12 nmol/g·min (comparison group) (p<0.001). Blood levels of FFA increased in group A up to 2.05±0.15, and in group B up to 2.48±0.20 mmol/l (while in it was 0.57±0.11 mmol/L). 8-oxoG levels in tumor-adjacent adipose tissue had no statistically significant differences. Conclusions. The tumor-adjacent adipose tissue is an energy depot that can act as a promoter of tumor progression supplying the locally advanced rectal cancer with an energy substrate FFA.  It has been established that the level MMP-2 activity significantly reduces the degree of intercellular matrix remodeling by the XELOX chemotherapy.