The significance of DNA methylation profile in metastasis-related genes for the progression of colorectal cancer.

DNA methylation, an epigenetic modification plays a role in the pathogenesis of colorectal cancer (CRC). CRC cases, both sporadic and familial, are often characterized by abnormal pattern of the cytosine methylation in CpG dinucleotides in regulatory regions of genes important for cancer transformation. Also genes mutated in CRC can have their epigenetic pattern altered and we suggest that changes in DNA methylation array can be important for CRC metastatic potential ‒ the main reason of CRC-associated mortality. These genes are: KRAS, genes of the Rho family of GTPases, MACC1, Met, MTA1 and RASSF1A. In addition, genes encoding miRNA important for epithelial mesenchymal transition and other metastasis-related effects, such as mir-9, miR-34 and miR-210 can be good candidates for associating their DNA methylation profiles with CRC metastasis. Analysis of DNA methylation profile in various stages of CRC along with other genetic/epigenetic changes specific for all main stages of CRC transformation could help in anti-metastatic therapy immediately after CRC diagnosis. However, targeting DNA methylation pattern in CRC therapy is a conception, which requires further work to precisely change DNA methylation array, without affecting genes, whose expression should not be changed.

Polymorphism of DNA mismatch repair genes in endometrial cancer.

UNLABELLED: Endometrial cancer (EC) is the second most common malignancy associated with hereditary non-polyposis colorectal cancer (HNPCC) family. The development of HNPCC is associated with defects in DNA mismatch repair (MMR) pathway resulting in microsatellite instability (MSI). MSI is present in a greater number of EC than can be accounted for by inherited MMR mutations, therefore alternative mechanisms may underline defective MMR in EC, including polymorphic variation. AIM: We checked the association between EC occurrence and two polymorphisms of MMR genes: a 1032G>A (rs4987188) transition in the hMSH2 gene resulting in a Gly22Asp substitution and a -93G>A (rs1800734) transition in the promoter of the hMLH1 gene. MATERIAL AND METHODS: These polymorphisms were genotyped in DNA from peripheral blood lymphocytes of 100 EC patients and 100 age-matched women by restriction fragment length polymorphism PCR. RESULTS: A positive association (OR 4.18; 95% CI 2.23-7.84) was found for the G/A genotype of the -93G>A polymorphism of the hMLH1 gene and EC occurrence. On the ot-her hand, the A allele of this polymorphism was associated with decreased EC occurrence. The Gly/Gly genotype slightly increased the effect of the -93G>A-G/A genotype (OR 4.52; CI 2.41-8.49). Our results suggest that the -93G>A polymorphism of the hMLH1 gene singly and in combination with the Gly322Asp polymorphism of the hMSH2 gene may increase the risk of EC.

Mutagenesis of mitochondrial DNA in Fuchs endothelial corneal dystrophy.

Fuchs endothelial corneal dystrophy (FECD) is an age-related, slowly progressive disease, which may lead to loss of vision resulting from apoptosis of corneal endothelial (CE) cells, dysfunction of Descemet membrane (DM) and corneal edema. A growing body of evidence suggests that oxidative stress may play a major role in the pathogenesis of FECD and that mitochondria of CE cells are its main target. Mitochondrial DNA (mtDNA) is particularly prone to oxidative stress and changes in mtDNA were reported in FECD patients. In the present work we studied mtDNA damage and repair, mtDNA copy number, and the 4977bp common deletion in mtDNA in DM cells and peripheral blood lymphocytes (PBLs) isolated from FECD patients. PBLs from 35 FECD patients and 32 controls were challenged for 10min with hydrogen peroxide at 20µM and then left in a fresh medium for 3h, resulting in a decrease in mtDNA copy number in both groups. Damage to mtDNA was not fully repaired after 3h and the extent of remaining lesions was significantly higher in the patients than the controls. We observed a higher copy number and an increased extent of mtDNA damage as well as a higher ratio of the common 4977bp deletion in DM cells of FECD patients than the controls. Our results confirm that mutagenesis of mtDNA may be involved in FECD pathogenesis and disturbance in mtDNA sensitivity to damaging agent as well as changes in mtDNA damage repair along with alternations in mtDNA copy number may underline this involvement.

Mutations in the PAX9 gene in sporadic oligodontia.

OBJECTIVES: Oligodontia, a congenital lack of six or more teeth, is often associated with mutations in the PAX9 gene; therefore, we searched for mutations in this gene. DESIGN: In the present work, we sequenced fragments of the PAX9 gene in individuals with sporadic oligodontia. Next, we genotyped some mutations we found in patients with oligodontia and individuals without tooth agenesis. SETTING AND SAMPLE POPULATION: DNA sequencing was performed in the material isolated from peripheral blood lymphocytes of six unrelated patients with sporadic, non-syndromic oligodontia. These patients were selected based upon explorative cluster analysis. Genotyping was performed in 38 patients with oligodontia and 100 control individuals. MATERIAL AND METHODS: Direct sequencing and restriction fragment length polymorphism PCR were employed. RESULTS: We detected two homozygotic substitutions, IVS2-109G>C and IVS2-54A>G, in intron 2 in three patients. Another homozygotic substitution in intron 2, IVS2-41A>G, was revealed in two patients. Two patients had an IVS3+40G>A homozygotic change in intron 3 and 4 patients displayed a 717C>T transition in exon 4 (silent mutation). One patient had a heterozygotic 718G>C transversion, resulting in a missense Ala240Pro substitution. We detected also several other intronic substitutions. Further genotyping of the IVS2-54A>G, IVS2-109G>C, and IVS2-41A>G mutations suggested that they can display polymorphic changes. CONCLUSION: The IVS2-54A>G, IVS2-109G>C, and IVS2-41A>G mutations of the PAX9 gene may represent polymorphism associated with sporadic oligodontia.

Association between polymorphisms of the BRCA2 gene and clinical parameters in breast cancer.

BACKGROUND: A C/T transition - rs4987117 (the Thr1915Met polymorphism) and an A/G transition - rs11571653 (the Met784Val polymorphism) in the BRCA2 gene were linked to breast cancer risk in Polish and Japanese populations, respectively. AIM: To study the association between polymorphisms of the BRCA2 gene and clinical parameters in breast cancer. METHODS: Both polymorphisms were evaluated by RFLP - PCR in blood samples obtained from 117 women with sporadic breast cancer. Patients were stratified by genotype, Bloom - Richardson grade, TNM stage, estrogene and progesterone receptors (PR) status and the linkages of each genotype with each stratum were calculated by logistic regression. RESULTS: Variant genotypes and alleles of both polymorphisms of the BRCA2 gene were inversely related to hormone receptor status for a group of patients with at least one positive receptor status as compared to a group with both receptors negative status (OR 0.27, 95% CI 0.07 - 0.95, p = 0.043 and OR 0.39, 95% CI 0.19 - 0.82, p = 0.013 for Met1915Met homozygote and 1915Met allele, respectively and OR 0.02, 95% CI 0.00 - 0.13, p = 0.0005 and OR 0.43, 95% CI 0.21 - 0.88, p = 0.021, for Val784Val homozygote and the 784Val allele. No association was found between both polymorphisms and Bloom - Richardson grading and TNM staging. CONCLUSIONS: Our results suggest that variant genotypes of the Thr1915Met and Met784Val polymorphisms of the BRCA2 gene may be indicative factors in therapy of ductal breast cancer.

Metabolic activity of neutrophils in patients suffering from chronic viral hepatitis.

The aim of the study was to evaluate the functional state of peripheral blood neutrophils in patients with chronic active viral hepatitis. Twenty-six patients with HBV, HCV or CMV in different clinical status were included in the analysis. In the study, the number of leukocytes and neutrophils was determined. The metabolic activity of neutrophils was examined in NBT reduction tests i.e. spontaneous (NBTsp) test and the one stimulated with LPS E. coli (NBTst). The results were analysed in relation to disease advancement and the type of viral infection. The data obtained from the affected patients were compared with the results from 46 healthy subjects. Most patients displayed neutropenia. It was found that the number of NBT positive cells and the coefficient of neutrophil metabolic activity (CNMA) in NBT sp test were highly significantly increased. The majority of patients had reduced values in NBTst test, which suggested lack of response to LPS E. coli by neutrophils. These findings may reflect the state of inflammation in the body. NBT reduction tests may be useful in monitoring metabolic activity of neutrophils in patients with chronic active viral hepatitis.

[Selected parameters of immune reactivity in patients with sensorineural hearing loss. III. Metabolic activity of neutrophils]. / Wybrane parametry reaktywnosci immunologicznej chorych z czuciowo-nerwowym uposledzeniem sluchu. III. Aktywnosc metaboliczna granulocytów obojetnochlonnych.

The evaluation of peripheral blood neutrophils functional state in 27 patients with progressive bilateral and 7 patients with sudden unilateral sensorineural hearing loss (SNHL) before and in the first period of ubiquitine therapy was performed. The metabolic activity of cells in NBT reduction tests: spontaneous (NBT-sp) and stimulated with LPS E. coli (NBT-st) were examined. The results in mean percentage and absolute number of NBT-positive cells, relative coefficient of neutrophil metabolic activity (CNMA) and also calculated NBT index were presented. Significant percentage of patients with increased NBT-sp test values before treatment and in the second examination were noticed. Relative CNMA was 3-6 times higher than normal values. The neutrophils of patients had a remarkably decreased ability to response to LPS stimulation. In patients with progressive bilateral SNHL during treatment with TFX considerable increase of patients (from 37.9 to 76.5%) with normal values in NBT-st reduction tests was found. The increased values of NBT-sp reduction tests and relative CNMA may suggest the presence of inflammation process or infection. The decreased values of NBT index which were observed confirm the existence of disturbances in neutrophils metabolic activity and lack of functional reserve of these cells. Usefulness of NBT reduction tests in patients with SNHL is discussed.

[Soluble class HLA antigens in serum of patients with brain tumors]. / Rozpuszczalne antygeny HLA klasy I w surowicach chorych na guzy mózgu.

The levels of soluble class I HLA antigens (s-HLA-I) in blood sera of patients with brain gliomas were studied before and after operation. It was found that sHLA material in sera was markedly decreased. The authors suggest the use of these examinations as one of the parameters of immune state of the oncologic patients before operation and in postoperative period.