Dynamic Changes in Circulating Methylated Markers in Response to Antitumor Therapy of Rectal Cancer.

Background: Rectal cancer (RC) occupies a leading position in the structure of oncological morbidity and mortality. Aberrant methylation of tumor-suppressor genes and hypomethylation of retrotransposons were shown to be detectable in cell-free DNA, circulating in the blood (cfDNA) of cancer patients, indicating the possibility to use them as diagnostic and prognosis markers.

Purpose: Evaluation of the changes in the methylation level of LINE-1 elements and SEPTIN9 and IKZF1 genes in the cell-surface-bound cfDNA (csb-cfDNA) from the blood of RC patients after antitumor therapy at a long-term follow-up.

The Composition of Small Extracellular Vesicles (sEVs) in the Blood Plasma of Colorectal Cancer Patients Reflects the Presence of Metabolic Syndrome and Correlates with Angiogenesis and the Effectiveness of Thermoradiation Therapy.

The majority of colorectal cancer patients (CRCPs) develop tumors on the background of "metabolically healthy obesity" or metabolic syndrome. The aim of the work was to study the levels of matrix metalloproteinases (MMPs) and heat shock proteins (HSPs) on the surface of blood plasma CD9-positive and FABP4-positive small extracellular vesicles (sEVs) from CRCPs depending on metabolic status and tumor angiogenesis, as well as to evaluate the sEVs markers as predictors of the effectiveness of thermoradiotherapy. In CRCPs, compared with patients with colorectal polyps (CPPs), the proportion of triple positive EVs and EVs with the MMP9+MMP2-TIMP1+ phenotype increased significantly among FABP4-positive EVs (adipocyte-derived EVs), which in general may indicate the overexpression of MMP9 and TIMP1 by adipocytes or adipose tissue macrophages in CRCPs.