Investigation of DNA damage in patients with colorectal cancer and investigation of the repairing role of beta-glucan on dna damage

DNA (Deoksiribo Nucleic Acid) is a biomolecule that provides continuity by transferring the genetic information of organisms to future generations and can be easily damaged by the effects of many reactive molecules. The damage is caused by changes in the physical and chemical structure of the DNA molecule or by environmental factors. DNA damage causes chromosomal abnormalities and mutations. Various techniques are used to accurately measure DNA damage. One of these methods is Single Cell Gel Electrophoresis (SCGE), also known as "Comet Assay Method". This technique; It is a non-invasive, fast, sensitive and simple fluorescent microscopic method used to detect DNA damage in many species. Comet Assay method; apoptosis, aging, clinical and genetic toxicology, oxidative stress-antioxidant studies. Beta glucan is a simple polysaccharide extracted from the cell wall of yeast (Saccharomyces cerevisiae), which strengthens the immune system, has a stimulating effect and creates an antioxidant effect. In this study, it was aimed to detect DNA damage by using Comet Assay method in whole blood samples taken from patients diagnosed with colorectal cancer and to prove the restorative effect of beta-glucan in ex vivo environment. A total of 19 adult male and female volunteers (40-80 years) who were diagnosed as stage 3-4 colorectal cancer who came to Gaziantep Medical Park Hospital Medical Oncology Department and Gaziantep University Medical Faculty Medical Oncology Department were studied ex vivo. The purpose of our study was explained to each patient who participated in the study and voluntary information form was given. Venous blood, which will be taken into sterile EDTA tubes in 10 ccs from volunteer patients, was brought to the laboratory under appropriate conditions and started to work. The DNA damage was determined by using Comet Assay test from whole blood. After each slide sample was stained with 50 μl/ml EtBr, images were taken on a fluorescence microscope and photographed. The Open Comet analysis program was used to analyze 100 cells in each field. In addition, a healthy volunteer control group consisting of 20 people was formed. Beta-glucan was not applied to this group. Glucan blood samples of the patient group were given 50 μl/ml beta glucan and 100 U / ml penicillin as antibiotics (Noss, 2012) and incubated for 12 hours at 37ºC in 5% CO2. To monitor the duration of action of beta-glucan, controls were performed from a minimum of the first 40 minutes. Beta glucan-treated samples were tested by the Comet Assay method. Samples were examined by staining on a fluorescent microscope and images were recorded by taking photographs. With Open Comet image analysis, 100 cells were analyzed in each field. The ability of beta-glucan to repair DNA damage was monitored. As a negative control, H2O2 (50 μmol / L) (Angelie et al., 2006) and duration (10 min) were administered to the blood samples of the patients. In the same way, the Comet Assay method was applied and the images were taken and analyzed under a microscope. DNA damage (in terms of tail DNA percentage, tail moment and tail length parameters) of patients with colorectal cancer (before starting treatment) was compared with DNA damage of control group (healthy individual) and then 50 μl/ml of Beta glucan DNA concentration repairing effect was investigated in patients diagnosed with colorectal cancer. The difference between the mean of the patient group and the control group was checked by t-test. The damage occurred in the DNAs of patients with colorectal cancer was examined by Comet method. It was determined that the tail torque, tail percentage, and tail length values increased significantly. After 12 hours of application of beta-glucan ex vivo in patients diagnosed with colorectal cancer, it was found statistically significant that DNA damage was significantly reduced by Comet Assay. When beta-glucan was administered to the patients with colorectal cancer, the results obtained were lower than the control group when compared with the control group values. The treatment results of beta-glucan may be lower than the control group, considering the possible damages in the control group. As a result; It can be said that beta-glucan has a restorative effect on DNA damage due to its anticytotoxic and antigenotoxic effects on colorectal cancer patients.