Jan Chojnacki

Polymorphisms in RAD51, XRCC2 and XRCC3 genes of the homologous recombination repair in colorectal cancer—a case control study

XRCC2 and XRCC3 proteins are structurally and functionally related to RAD51 which play an important role in the homologous recombination, the process frequently involved in cancer transformation. In our previous work we show that the 135G>C polymorphism (rs1801320) of the RAD51 gene can modify the effect of the Thr241Met polymorphism (rs861539) of the XRCC3 gene. We tested the association between the 135G>C polymorphism of the RAD51 gene, the Thr241Met polymorphism of the XRCC3 gene and the Arg188His polymorphism (rs3218536) of the XRCC2 gene and colorectal cancer risk and clinicopathological parameters. Polymorphisms were evaluated by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) in 100 patients with invasive adenocarcinoma of the colon and in 100 sex, age and ethnicity matched cancer–free controls. We stratified the patients by genotypes, tumour Duke’s and TNM stage and calculated the linkage of each genotype with each stratum. Carriers of Arg188Arg/Me241tMet, His188His/Thr241Thr and His188His/G135G genotypes had an increased risk of colorectal cancer occurrence (OR 5.70, 95% CI 1.10–29.5; OR 12.4, 95% CI 1.63–94.9; OR 5.88, 95% CI 1.21–28.5, respectively). The C135C genotype decreased the risk of colorectal cancer singly (OR 0.06, 95% CI 0.02–0.22) as well as in combination with other two polymorphisms. TNM and Duke’s staging were not related to any of these polymorphisms. Our results suggest that the 135G>C polymorphism of the RAD51 gene can be an independent marker of colorectal cancer risk. The Thr241Met polymorphism of the XRCC3 gene and the Arg188His polymorphism of the XRCC2 gene can modify the risk of colorectal cancer.

Therapeutic effect of melatonin in patients with functional dyspepsia

Background and Goal Melatonin may inhibit reactive oxygen species-related pathogenesis in the alimentary tract by neutralizing free radicals. In the present study we assessed the potential protective action of melatonin in ulcerlike dyspepsia. Study Sixty patients aged 19 to 39 years with the diagnosis of functional dyspepsia according to the Rome Criteria II and no Helicobacter pylori infection were involved in the study. Melatonin, at a dose of 5 mg (n=30), or placebo (n=30) were taken in the evening for a period of 12 weeks. At this time, patients were on an equivalent diet and were only to take an alkaline drug in case of the abdominal pain. Results After 12 weeks, the dyspeptic symptoms completely subsided in 17 patients in the melatonin-treatment group (56.6%). In other 9 individuals (30.0%) a partial improvement in health was achieved, especially in the frequency and intensity of nocturnal pain. After placebo, the majority of patients (93.3%) did not experience any improvement in symptoms. Multivariate analysis indicated that melatonin (odds ratio 95.86, 95% confidence interval 3.72-2469.37, P<0.01) correlated independently with significantly improved patients health. H. pylori past infection decreased positive effect of melatonin in ulcerlike dyspepsia. Conclusions Melatonin can be considered as an auxiliary drug in the treatment of ulcerlike dyspepsia.

The lL-8 and IL-13 Gene Polymorphisms in Inflammatory Bowel Disease and Colorectal Cancer

Inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are disorders that originate from immune disturbances. In our study, we evaluated the association between the -251 T/A interleukin (IL)-8 and the -1112 C/T IL-13 polymorphisms, the risk of IBD, and CRC development. Genotypes were determined by PCR-restriction fragment length polymorphism in 191 patients with CRC, 150 subjects with IBD, and 205 healthy controls. We found an association between CRC and the presence of the -251 TA genotype and A allele of the IL-8 gene (odds ratios [ORs] 2.28 and 1.65). A similar relationship was observed between these polymorphic variants and ulcerative colitis (OR 2.05 for the -251 TA genotype and OR 1.47 for the -251 A allele) as well as Crohns disease (ORs 3.11 and 1.56, respectively). Our research also revealed that the CT and TT genotypes of the IL-13 -1112 C/T polymorphism may be connected with a higher risk of CRC (ORs 2.28 and 1.65). The same genotypes affected the susceptibility of IBD (ORs 2.26 and 3.72). Our data showed that the IL-8 -251 T/A and IL-13 -1112 C/T polymorphisms might be associated with the IBD and CRC occurrence and might be used as predictive factors of these diseases in a Polish population.

Evaluation of enterochromaffin cells and melatonin secretion exponents in ulcerative colitis.

AIM To study an assessment of the number of enterochromaffin cells and expression of hydroxyindole-O-methyltransferase in colonic mucosa and urine excretion of 6-sulfatoxymelatonin in patients with ulcerative colitis. METHODS The study included 30 healthy subjects (group I-C), 30 patients with ulcerative proctitis [group II-ulcerative proctitis (UP)] and 30 patients with ulcerative colitis [group III-ulcerative colitis (UC)] in acute phases of these diseases. The number of enterochromaffin cells (EC) was estimated in rectal and colonic mucosa. Bioptates were assembled from many different parts of the large intestine. Immunorective cells collected from various parts of the colon were counted according to the Eurovision DAKO (Dako A/S, Copenhagen, Denmark) System in the range of 10 fields in each bioptate at × 200 magnification. The level of mRNA expression of hydroxyindole-O-methyltransferase (HIOMT) in colonic mucosa was estimated with RT-PCR. Urine 6-sulfatoxymelatonin (6-HMS) excretion was determined immunoenzymatically using an IBL (IBL International GmbH, Hamburg, Germany) kit (RE 54031). RESULTS The number of EC cells in healthy subjects (C) was 132.40 ± 31.26. In patients of group II (UP) and group III (UC) the number of these cells was higher--225.40 ± 37.35 (P < 0.001) and--225.24 ± 40.50 (P < 0.001) respectively. Similar differences were related to HIOMT expression, which was 1.04 ± 0.36 in group C, 1.56 ± 0.56 (P < 0.01) in group UP and 2.00 ± 0.35 (P < 0.001) in group UC. Twenty-four hour 6-HMS urinary excretion was as follows: C--6.32 ± 4.95 μg/24 h, UP - 26.30 ± 7.29 μg/24 h (P < 0.01), UC--2.30 ± 12.56 μg/24 h (P < 0.001). A correlation between number of EC cells and 6-HMS excretion was noted in all groups: r = 0.766 in patients with UP, r = 0.703 with UC and r = 0.8551 in the control group; the correlation between the results is statistically significant. CONCLUSION In the acute phases of both UP and UC, proliferation of EC cells and high expression of HIOMT and urine excretion of 6-HMS is noted. These changes may represent a beneficial response in the anti-inflammatory and defense mechanism.

Helicobacter pylori infection and antioxidants can modulate the genotoxic effects of heterocyclic amines in gastric mucosa cells.

Helicobacter pylori (H. pylori) infection plays an important role in gastric carcinogenesis. This bacterium may induce cancer transformation and change the susceptibility of gastric mucosa cells to various exogenous dietary irritants. The aim of the study was to evaluate the influence of H. pylori infection on the reaction of the stomach cells to a genotoxic effect of heterocyclic amines (HCAs). These well-known mutagens are formed during cooking of protein-rich foods, primarily meat. Taking into account that persons consuming a mixed-western diet are exposed to these compound nearly an entire lifetime and more than half of human population is infected with H. pylori, it is important to assess the combined effect of H. pylori infection and HCAs in the context of DNA damage in gastric mucosa cells, which is a prerequisite to cancer transformation. We employed 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) because these substances are present in a great amount in cooked and fried meat. Using alkaline comet assay, we showed that the extent of the DNA damage induced by HCAs was significantly higher in H. pylori infected gastric mucosa cells than in non-infected counterparts. We did not observed any difference in the efficiency of repair of DNA lesions induced by HCAs in both type of cells. Vitamin C reduced the genotoxic effects of HCAs in H. pylori infected and non-infected gastric mucosa cells. Melatonin more effectively decreased DNA damage caused by HCAs in H. pylori infected gastric mucosa cells as compared with control. Our results suggest that H. pylori infection may influence the susceptibility of gastric mucosa cells to HCAs and dietary antioxidative substances, including vitamin C and melatonin may inhibit the genotoxic effects of HCAs on gastric mucosa cells and may reduce the risk of carcinogenesis caused by food borne mutagens and H. pylori infection.

Melatonin secretion and metabolism in patients with hepatic encephalopathy

The rhythm of melatonin secretion and its blood level changes in cirrhotic patients, but the causes of these alterations have not been sufficiently appreciated.

Secretion of melatonin and 6-sulfatoxymelatonin urinary excretion in functional dyspepsia.

AIM To evaluate blood concentration of melatonin and urinary excretion of its metabolite, 6-sulfatoxymelatonin (6-OHMS), in functional dyspepsia (FD). METHODS Ninety individuals were enrolled in the study: 30 in each study group: patients with postprandial distress syndrome (PDS), epigastric pain syndrome (EPS), and controls. Blood samples were drawn at 02:00 and 09:00 h and 24-h urine collection was performed. Serum melatonin and urinary 6-OHMS concentrations were measured by enzyme-linked immunosorbent assay. RESULTS Serum melatonin concentration at night and in the morning was significantly (P < 0.001) higher in PDS patients [at 02:00 h-93.3 pg/mL, quartile range (QR): 79.8-116.2; at 09.00 h-14.3 pg/mL, QR: 7.06-19.0] than in EPS (57.2 pg/mL, QR: 42.6-73.1; 8.1 pg/mL, QR: 4.1-9.3) and control patients (57.7 pg/mL, QR: 51.2-62.5; 8.1 pg/mL, QR: 5.4-10.3). A similar relationship was observed for urinary 6-OHMS excretion. Patients with severe PDS symptoms had a higher melatonin concentration than these with moderate syndromes, whereas patients with severe EPS had a lower urinary 6-OHMS excretion than patients with moderate symptoms. CONCLUSION Evaluation of melatonin serum concentrations and 24-h urinary 6-OHMS excretion are useful methods for differential diagnosis of various clinical forms of FD.

The effect of melatonin supplementation on the quality of sleep and weight status in postmenopausal women

Aim of the study We evaluated the effect of melatonin supplementation on the nutritional status of postmenopausal women. Material and methods The study included 56 women (51-65 years) and 25 healthy women (27-36 years). The emotional state was assessed using Hamilton Depression Rating Scale (HAM-D), the quality of sleep using Insomnia Severity Index (ISI). Body mass index (BMI) and waist-hip ratio (WHR) were also calculated. The patients were divided into 3 groups: group I (control) – 25 women with normal body weight, group II – 26 postmenopausal women with normal body weight, group III – 30 postmenopausal women with high body weight. In women from group II and III, routine laboratory tests, levels of thyroid-stimulating hormone (TSH), 17β-estradiol, prolactin, follicle-stimulating hormone (FSH) and the concentration of 6-hydroxymelatonin sulphate (6-HMS) in day/night urine fractions were determined. On the day of the examination, women remained on a liquid diet (1800 kcal). Next, a balanced diet of 1500 kcal and 5 mg of melatonin administration were recommended. The follow-up examinations were performed after 4, 8, 12, 16, 20 and 24 weeks. Results The patients from groups II and III showed similar mild levels of anxiety and depression and a significant degree of sleep disorders. In group III, lower urinary 6-HMS excretion was observed at night. In both groups a negative correlation was found between urinary 6-HMS excretion and the degree of sleep disorders. After 24 weeks, a statistically significant improvement of quality of sleep was obtained. A negative correlation was detected between urinary 6-HMS excretion and BMI. Conclusion Melatonin supplementation contributed to body weight reduction.

Expression of somatostatin receptor subtype 3 in the gastric mucosa of dyspeptic patients in relation to Helicobacter pylori infection and a family history of gastric cancer

Background and Aim:  The cytotoxic activity of Helicobacter pylori contributes significantly to the pathogenesis of gastric carcinoma. A preliminary study suggested that somatostatin receptor subtype 3 (SSTR3) might play a role in cell apoptosis and the growth of gastric cancer. The aim of the present study was to determine the influence of H. pylori infection and a family history of gastric cancer on the expression of SSTR3 in the gastric mucosa of non‐cancer patients with dyspepsia.

Melatonin and Female Hormone Secretion in Postmenopausal Overweight Women

Estrogen deficiency is considered to be the main cause of increased appetite and increased weight in postmenopausal women. In this period, reduced secretion of melatonin (MEL) was also observed. The aim of the study was to evaluate the secretion of melatonin, 17-β estradiol and follicle-stimulating hormone (FSH) in relation to body mass index (BMI) in pre- and postmenopausal women. The study included 90 women divided into three equal groups: group I (control)—women without menstrual disorders, group II—postmenopausal women without change in appetite and body weight, group III—postmenopausal women experiencing increased appetite and weight gain. In each patient, serum melatonin, 17-β-estradiol, FSH and urine a 6-sulfatoxymelatonin (aMT6s) were determined. Compared to the control group, the level of melatonin and estradiol was statistically lower. The FSH level was higher than in the groups of postmenopausal women. No significant correlation was found in all groups between the level of melatonin and the levels of estradiol and FSH. A negative correlation was found between aMT6s excretion and BMI, and a positive correlation between the level of FSH and BMI, mainly in overweight women. The obtained results indicate a significant effect of melatonin deficiency on the process of weight gain in postmenopausal women and justify its use in treatment of these disorders.