Features of neoangiogenesis marker ang-2 expression in rectal adenocarcinoma tissues under the influence of neoadjuvant chemoradiotherapy

Abstract

The aim of the study was to determine Ang-2 expression patterns in intact colon tissue and rectal cancer (RC) before treatment and after a course of neoadjuvantchemoradiotherapy (NCRT), including with the polyradiomodification using tegafur and L-arginine hydrochloride. Ang-2 expression was determined by immunohistochemistry in the biopsy and surgical material before and after NCRT in 21 patients with adenocarcinoma of the rectum stage II-III. There was an inverse correlation between differentiation degree of RC and the level of post radiation therapeutic pathomorphosis on the one hand, and the level of Ang-2 expression in tumor tissue – on the other, which suggests the possibility of using Ang-2 as a marker for assessing the malignant potential of the RC and the NHLT application effectiveness. It was found that the use of nitric oxide biosynthesis precursor L-arginine hydrochloride as a component of polyradiomodification potentiates direct NCRT damaging effect on tumor parenchyma and also suppresses the activity of tumor-associated neoangiogenesis.