Feride Iffet Sahin

Chromosome heteromorphisms: an impact on infertility

IntroductionCytogenetic heteromorphisms are described as heritable variations at specific chromosomal regions without a proven impact on phenotype.Materials and methodsWe compared the presence of chromosome heteromorphisms in the karyotypes of two patient groups. The first group of patients consisted of 276 individuals of 138 infertile couples. The second group, consisted of 1,130 amniocentesis samples. This group was considered to be a sample of the fertile population, as the fetus being karyotyped is the result of a spontaneous pregnancy. Fetal karyotyping was made due to the standard indications for prenatal diagnosis, such as abnormal maternal serum screening results. Results and discussionEighteen infertile patients (6.52%) and twenty fetuses (1.77%) were found to have chromosome heteromorphisms. The difference between the two groups was statistically significant (p < 0.0001).ConclusionThese results are consistent with other similar studies that suggest the yet undefined relationship between chromosome heteromorphisms and infertility.

Human bone marrow mesenchymal cells express NG2: possible increase in discriminative ability of flow cytometry during mesenchymal stromal cell identification

BACKGROUND AIMS Mesenchymal stromal cells (MSC) exhibit non-specific hematopoietic cell and/or stromal cell markers (e.g. CD73, CD105 and CD166) that have been used to identify MSC by flow cytometry. Because a neural glial antigen, NG2 (a progenitor cell marker in the central nervous system), is expressed by several tissue cells originating in the mesenchyme but not hematopoietic cells, it might be useful for isolating and identifying MSC. We investigated NG2 expression on culture-expanded MSC by flow cytometry. METHODS Human bone marrow (BM) samples taken from 12 donors were cultured for MSC to be used in up to nine serial passages. Using flow cytometry, the neural glial antigen NG2 and commonly used MSC markers CD73, CD105 and CD166, were analyzed on the surface of culture-expanded MSC. The multipotential differentiation of the MSC was examined by adipogenic and osteogenic induction. RESULTS The percentage of cells positive for NG2 was similar to the percentages of cells positive for CD73, CD105 and CD166 in all passages of BM samples. The mean fluorescent intensities of NG2 did not change with culture passage. The MSC was successfully differentiated into adipogenic and osteogenic lines. The cells showed no karyotypic abnormalities. CONCLUSIONS NG2 seems to be a promising marker for investigating the biology of MSC.

Conventional and molecular cytogenetic findings of myelodysplastic syndrome patients.

AbstractMyelodysplastic syndrome (MDS) involves myeloid cells of the bone marrow, which is important in progressive bone marrow insufficiency. Of all MDS patients, 40%–50% have at least one chromosomal rearrangement. Loss of specific chromosomal regions like 5q– and 7q– are usually the secondary cytogenetic abnormalities associated with MDS. In order to detect chromosome abnormalities associated with MDS, bone marrow samples from 26 patients diagnosed as MDS were obtained prior to chemotherapy. Both conventional cytogenetic analyses and fluorescence in situ hybridisation (FISH) methods were performed and locus–specific probes for 5q and 7q were used. Results obtained were compared. Twenty–one patients had normal karyotypes and four patients had abnormal karyotypes, while in one patient we could not obtain metaphases from cultures. Three patients with normal karyotypes revealed del (5q), two patients had del (7q) and one patient had monosomy (7). A total of 10 of 26 patients had chromosome changes visualised by either conventional or molecular cytogenetics (~38.5%). Our results show that both methods are important in diagnosis and follow up of MDS patients. When used together, conventional cytogenetics and FISH detect clinically significant chromosome abnormalities in MDS patients.

Detection and Typing of Human Papillomavirus in Non-Small Cell Lung Cancer

Background: Lung cancer is the most frequent cause of death in both men and women. Smoking is the greatest risk factor for lung cancer and the relation of human papillomavirus (HPV) infection with lung cancer has been reported. HPV can be detected in small cell lung cancer samples with the methods like in situ hybridization, polymerase chain reaction (PCR), Southern blotting, dot blotting. Objective: We aimed to detect and type HPV infection in non-small cell lung carcinoma tissue samples. Methods: Tumor samples from 40 patients were collected during surgery and PCR and restriction fragment length polymorphism (RFLP) were used in order to detect HPV infection in the samples. Results: Two HPV DNA were detected among 40 of the patients, revealing a low frequency of HPV in the samples. Conclusions: HPV can be regarded as an environmental factor in tumor development. There might be a relationship between HPV infection and some non-small cell lung cancers, especially in the smoking group.

Detecting methylation patterns of p16, MGMT, DAPK and E-cadherin genes in multiple myeloma patients.

Multiple myeloma (MM) is a B‐cell neoplasia characterized by the clonal proliferation of plasma cells. Besides known genetic abnormalities, epigenetic changes are also known to effect MM pathogenesis. DNA methylation is an epigenetic mechanism that silences genes by adding methyl groups to cytosine‐guanine dinucleotides at the promoter regions. In this study, the methylation status of four genes; p16, O6‐methyl guanine DNA methyl transferase (MGMT), death‐associated protein kinase (DAPK) and E‐cadherin (ECAD); at the time of diagnosis was investigated using methylation‐specific polymerase chain reaction (MS‐PCR). In the 20 cases studied; methylation of the promoter regions of p16, MGMT, DAPK and ECAD genes was detected in 10%, 40%, 10% and 45% of the cases, respectively. In 65% (13/20) of cases, at least one of the genes studied had promoter methylation; while 35% of cases (7/20) had methylated promoters of more than one gene. There was a significant correlation between promoter hypermethylation of MGMT and the presence of extramedullary involvement; but for the other genes no correlation was found regarding disease properties like age, disease stage, clinical course and the presence of lytic bone lesions. Determining the methylation profiles of genes in MM, could lead to a new understanding of the disease pathogenesis and guide the assessment of treatment options.

Fluorescent in situ hybridization studies in multiple myeloma.

Abstract Conventional cytogenetic analysis and fluorescence in situ hybridization (FISH) results of bone marrow samples of 36 multiple myeloma (MM) patients at the time of diagnosis have been evaluated. Three probes for chromosome 13q (RB1, D13S319, D13S25), one for 14q32 (IgH) and one for 17p13 (p53) have been used for hybridization with fixed cells. Twenty patients (55·5%) had normal karyotypes, whereas eight (22·2%) had numerical or structural chromosomal abnormalities. We did not find metaphases for chromosome analysis in eight (22·2%) patients. Fluorescence in situ hybridization analyses revealed at least one or more abnormal results in 25 (69·5%) cases, whereas 11(30·5%) cases had no abnormal findings. 14q32 rearrangement was the most common finding in FISH analyses and has been detected in 21 cases (58·3%). 13q deletion and 17p deletion have been detected in 11 (30·5%) and 5 (13·9%) cases, respectively. Fluorescence in situ hybridization studies including 14q32 and 17p13 chromosome regions may yield quite significant results during clinical follow-up of MM.

Matrix metalloproteinase-9 promoter gene polymorphism (-1562C>T) in nasal polyposis.

Background Expression of matrix metalloproteinase (MMP)-9 increases in nasal polyp tissues. However, the impact of MMP-9 genotypes on the development of nasal polyposis (NP) is unknown. The aim of this study was to examine a potential association of MMP-9 promoter gene polymorphism with the development of NP. Methods A prospective and case–control study was performed on 93 patients with NP and 115 controls without sinonasal disease. Genotypes of MMP-9 (–1562C>T) were identified by restriction fragment length polymorphism analyses after polymerase chain reaction. Results The frequency of – 1562CT genotype of MMP-9 was significantly high in NP patients with aspirin-induced asthma (p = 0.014). Distribution of T allele was significantly high in NP patients with aspirin-induced asthma (p = 0.013). MMP-9 genotypes were not associated with gender or the presence of atopy. Conclusion In this study, MMP-9 – 1562CT genotype was associated with susceptibility to NP in aspirin-induced asthmatic patients. Because this report is a population-based study, further research should be performed on larger study subjects to reveal the precise role of MMP-9 promoter gene polymorphism in the development of NP.

Interaction of Cultured Chondrocytes with Chitosan Scaffold

Chitosan scaffolds with sponge-like structures were prepared by a wet spinning technique. Glutaraldehyde was used to control the swellability (water uptake) of the scaffolds. It was possible to reach a swelling ratio about 56.8% in aqueous medium. These wet scaffolds were soft and easily shaped by hand. The cartilage specimen was obtained from the knee joints of a New Zealand white rabbit. Chondrocyte cells were isolated and cultured in vitro for about 10 days to reach a usable population. The cells were then incubated with the chitosan scaffolds and interactions were examined by microscopy. Chondrocyte cells showed junctional complexes consisting of plaques and filaments at the interface. Cell membranes were strongly attached on the chitosan surface.

beta-Adrenoreceptor antagonists reduce cancer cell proliferation, invasion, and migration

Abstract Context: Propranolol, atenolol, and ICI118,551 are non-selective β-adrenergic receptor (AR), β1-AR, and β2-AR antagonists, respectively. Objective: We investigated the efficacy of propranolol, atenolol, and ICI118,551 on proliferation, migration, and invasion of non-stimulated breast (MCF7), colon (HT-29), and hepatocellular (HepG2) cancer cells. Materials and methods: β-AR expression profiling of cells was performed by real time PCR. Cell proliferation was determined by MTT. Boyden chamber and scratch assays were performed to evaluate invasion and migration. Results and discussion: All cell lines expressed β-ARs. ICI118,551 was the most cytotoxic, whereas atenolol was the least effective β-AR antagonist for 24, 48, and 72 h. Cell invasion was inhibited by ICI118,551 (45, 46, and 50% for MCF7, HT29, and HepG2, respectively) and propranolol (72, 65, and 90% for MCF7, HT29, and HepG2, respectively). Propranolol, atenolol, and ICI118,551 reduced migration of MCF7, HT-29, and HepG2 cells to varying extents depending on the application concentration and duration. Propranolol and atenolol reduced migration of MCF7 and HT-29 in a concentration-dependent manner, whereas migration of these cells decreased after 48 and 72 h of ICI118,551 applications. Conclusion: Beta2-AR antagonist seemed to be the most cytotoxic β-blocker on non-stimulated cancer cells. Propranolol and ICI118,551 were more effective than atenolol in inhibiting invasion and migration of non-stimulated MCF7 and HT-29 cells; ICI118,551 being the most potent. Concordantly, β2-selective blockage seemed to be more effective for non-stimulated cells. Effect of the selective β-AR antagonists showed variation depending on the concentration, incubation time, and histological origin of cells.

Identification of Promoter Region Methylation Patterns of MGMT, CDKN2A, GSTP1, and THBS1 Genes in Intracranial Meningioma Patients

BACKGROUND Cytogenetic, molecular and epigenetic changes are all known to take place in the pathogenesis of meningiomas. In this study, we aimed at investing methylation of MGMT (DNA repair), CDKN2A (cell cycle control), GSTP1 (detoxification), and THBS1 (angiogenesis inhibitor) genes, which are known to be unmethylated in normal tissue, in meningioma samples. MATERIALS AND METHODS Methylation specific polymerase chain reaction was used to study promoter regions methylation of genes in 36 patient samples. RESULTS Methylation in promoter regions of MGMT, CDKN2A, GSTP1, and THBS1 genes were found in 11.1%, 8.3%, 2.8%, and 0% of the cases, respectively. About 19.4% of cases revealed promoter methylation of at least a single gene, whereas only 2.8% of cases revealed methylation of more than one gene. Based on their World Health Organization 2007 grade; 6.3% of grade I cases, 35.3% of grade II cases, and 33.3% of grade III cases showed hypermethylation in the promoter regions of the genes studied. No statistically significant relation was found between promoter zone methylation and factors such as age, sex, histopathology, grade, or recurrence. CONCLUSIONS Further research on promoter zone methylation will help expose the methylation profile and pathogenesis of meningiomas, which will consequently guide to a deeper understanding of the pathogenesis of the disease, thus ensuring a better understanding of the prognosis and considering novel treatment options.