[Investigation of the Effect of Farnesol on Biofilm Formation by Candida albicans and Candida parapsilosis Complex Isolates]. / Candida albicans ve Candida parapsilosis Kompleks Izolatlarinin Biyofilm Üretimi Üzerine Farnesol Etkisinin Arastirilmasi.

The incidence of infections caused by Candida species has significantly increased over the past three decades. Candida albicans is commonly recognized as the primary causative agent in cases of candidiasis; however, non-albicans Candida species, including Candida parapsilosis, are also frequently defined as pathogens. Treatment-resistant infections arise as a result of biofilm formation, which is one of the effective mechanisms in the pathogenesis of Candida infections. However, the mechanisms of action of farnesol, a quorum sensing (QS) system molecule, on biofilm formation by Candida species remain unclear. This study aimed to demonstrate the changes in the biofilm biomass of C.albicans and C.parapsilosis complex isolates in the presence of farnesol and reveal the expression of the EFG1 and BCR1 genes, which are believed to play a role in the production of QS molecules, using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis. C.albicans (n= 91) and C.parapsilosis complex (n= 29) isolates obtained from different clinical samples were included in the study. The minimum inhibitory concentration (MIC) values of farnesol were determined using the broth microdilution method according to the M27-A3 protocol of the Clinical and Laboratory Standards Institute (CLSI). The biofilm biomass of the isolates was examined without farnesol and at the MIC-0 and MIC-2 concentrations of farnesol. Changes in the expression of the biofilm-associated EFG1 and BCR1 genes were investigated using qRT-PCR. According to the results of the study, the MIC values of farnesol were detected in the range of 1-2 mM in 82.4% (n= 75) of the C.albicans isolates and in the range of 0.5-1 mM in 72.4% (n= 21) of the C.parapsilosis complex isolates. Of the C.albicans isolates, 27 (29.7%) exhibited a strong biofilm formation and 58 (63.7%) demonstrated a weaker biofilm formation, while these rates were 34.4% (n= 10) and 62.1% (n= 18), respectively, for the C.parapsilosis complex isolates. At the MIC-0 and MIC-2 concentrations, farnesol was observed to reduce biofilm biomass among C.albicans (n= 24, 88.9%) and C.parapsilosis complex (n= 8, 80.0%) isolates that formed strong biofilms and observed to increase biofilm biomass among those that formed weak biofilms [60.3% (n= 35) and 55.6% (n= 10), respectively]. On completion of the qRT-PCR analysis supporting the results of the biofilm experiment, it was determined that the expressions of the EFG1 and BCR1 genes decreased at the MIC-0 and MIC-2 concentrations of farnesol among the strong biofilm-forming C.albicans and C.parapsilosis complex isolates, but there was an increase in gene expressions among the weak biofilm-forming isolates. In addition to the antifungal effect of farnesol on Candida species, this study provided data on the efficacy of the MIC-0 and MIC-2 concentrations of farnesol against Candida biofilm biomass. Although our results suggest that farnesol can be used as an alternative agent to reduce biofilm formation in Candida infections, they need to be supported by further studies. Moreover, this research has significance as it represents the first study to determine the EFG1 and BCR1 gene expressions among C.parapsilosis complex isolates in the presence of farnesol.

miR-320a promotes p53-dependent apoptosis of prostate cancer cells by negatively regulating TP73-AS1 invitro.

TP73 antisense RNA 1 (TP73-AS1) is an oncogenic long non-coding RNA that is activated in several types of cancers. It has been shown that the activity of TP73-AS1 is controlled by several miRNAs, but post-transcriptional mechanisms that regulate TP73-AS1 activity in prostate cancer remain highly elusive. Accordingly, in the present study, we aimed to determine the miRNAs that are involved in the regulation of TP73-AS1 in prostate cancer and to show the effects of these molecules on the malignant proliferation of prostate cancer cells. Remarkably, colony formation and cell migration were suppressed while cell cycle arrest and apoptosis were induced in prostate cancer cells overexpressing miR-200a and miR-320a. miR-200a and miR-320a were found to be upregulated in TP73-AS1 suppressed prostate cancer cells. Also, TP73-AS1 was shown to be downregulated following miR-200a and miR-320a overexpression. However, overexpression of miR-320a had no significant effect on the expression of TP73. Further analysis revealed that miR-320a induces p53-dependent apoptosis. Consequently, our findings indicate that miR-320a induces p53-dependent apoptosis by negatively regulating TP73-AS1 long non-coding RNA.

Silencing of TP73-AS1 impairs prostate cancer cell proliferation and induces apoptosis via regulation of TP73.

BACKGROUND: Prostate cancer is a malignant disease that severely affects the health and comfort of the male population. The long non-coding RNA TP73-AS1 has been shown to be involved in the malignant transformation of various human cancers. However, whether TP73-AS1 contributes to prostate cancer progression has not been reported yet. Accordingly, here we aimed to report the role of TP73-AS1 in the development and progression of prostate cancer and determine its relationship with TP73. METHODS AND RESULTS: TP73-AS1-specific siRNA oligo duplexes were used to silence TP73-AS1 in DU-145 and PC-3 cells. Results indicated that TP73-AS1 was upregulated whereas TP73 was downregulated in prostate cancer cells compared to normal prostate cells and there was a negative correlation between them. Besides, loss of function experiments of TP73-AS1 in prostate cancer cells strongly induced cellular apoptosis, interfered with the cell cycle progression, and modulated related pro- and anti-apoptotic gene expression. Colony formation and migration capacities of TP73-AS1-silenced prostate cancer cells were also found to be dramatically reduced. CONCLUSIONS: Our findings provide novel evidence that suggests a chief regulatory role for the TP73-TP73-AS1 axis in prostate cancer development and progression, suggesting that the TP73/TP73-AS1 axis can be a promising diagnostic and therapeutic target for prostate cancer.

Relationship between vitamin D in obstructive sleep apnea syndrome and psoriasis patients.

Introduction: Although psoriasis and obstructive sleep apnea syndrome (OSAS) are associated with systemic inflammation, studies on their potential bilateral relationship are not sufficient. Aim: To investigate vitamin D levels and receptor gene polymorphisms in patients with OSAS and psoriasis and the associations with these diseases. Material and methods: One hundred thirty-seven patients included in the study consisted of 4 different groups: group 1, those with both diseases; group 2, those with OSAS only; group 3, patients with psoriasis only; and group 4, healthy controls. The patients' serum calcium, phosphorus, AHI, Epworth Sleepiness Scale, Psoriasis Area Severity Index, and VDR TagI, ApaI, BsmI polymorphisms were compared. Results: Vitamin D levels of groups 1, 2 and 3 were found to be lower than in controls. There was no statistically significant correlation between VDR TagI, ApaI, BsmI gene polymorphisms of the groups. Vitamin D levels were significantly higher in patients with heterozygous ApaI genotype (A/C) compared to patients with normal (A/A) or homozygous mutant (C/C) genotype (p < 0.05). No relationship was determined between VDR TagI, ApaI, BsmI, and the other parameters. Conclusions: In our study, 1,25(OH)2-vitamin D3 levels were significantly lower in all disease groups compared to the control group. Although there is no difference between the groups in terms of VDR gene polymorphism, we think that there may be a bidirectional relationship between these diseases based on the low vitamin D levels.

DNA repair and apoptosis: Roles in radiotherapy-related acute reactions in breast cancer patients.

Normal tissue reactions are therapy limiting factor for the effectiveness of the radiotherapy in cancer patients. DNA repair and apoptosis are estimated to be critical players of adverse effects in response to radiotherapy. Our aim was to define the association of DNA repair (ERCC1 and XPC) and apoptotic (BCL2, CASP3 and NFKB1) gene expression, DNA damage levels, apoptosis changes and DNA repair gene variations with the risk of acute side effects in breast cancer patients. The study included 100 women with newly diagnosed breast cancer; an experimental case group (n=50) with acute side effects and the control group (n=50) without side effects. Gene expression was analyzed by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR). Micronucleus (MN) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) assays were performed to compare the DNA damage levels. Apoptosis was examined by TDT-mediated dUTP-biotin nick end-labeling (TUNEL) staining. ERCC1 rs3212986 and XPC rs3731055 polymorphisms were genotyped by real-time PCR technique. No significantly correlation of DNA repair and apoptosis gene expression and DNA damage levels with acute side effects in response to radiotherapy. Also, there was no association between apoptosis levels and acute effects. ERCC1 rs3212986 CC genotype showed a protective effect against radiotherapy-induced acute reactions (p<0.001; OR: 0.21; 95% CI= 0.08-0.52). Our results suggest that apoptosis and DNA damage levels are not associated with acute radiosensitivity. DNA repair may affect the risk of acute reactions. Further studies are needed to validate the current findings.

Fhit loss-associated initiation and progression of neoplasia in vitro.

The FHIT gene, encompassing an active common fragile site, FRA3B, is frequently silenced in preneoplasia and cancer, through gene rearrangement or methylation of regulatory sequences. Silencing of Fhit protein expression causes thymidine kinase 1 downregulation, resulting in dNTP imbalance, and spontaneous replication stress that leads to chromosomal aberrations, allele copy number variations, insertions/deletions, and single-base substitutions. Thus, Fhit, which is reduced in expression in the majority of human cancers, is a genome "caretaker" whose loss initiates genome instability in preneoplastic lesions. To follow the early genetic alterations and functional changes induced by Fhit loss that may recapitulate the neoplastic process in vitro, we established epithelial cell lines from kidney tissues of Fhit-/- and +/+ mouse pups early after weaning, and subjected cell cultures to nutritional and carcinogen stress, which +/+ cells did not survive. Through transcriptome profiling and protein expression analysis, we observed changes in the Trp53/p21 and survivin apoptotic pathways in -/- cells, and in expression of proteins involved in epithelial-mesenchymal transition. Some Fhit-deficient cell lines showed anchorage-independent colony formation and increased invasive capacity in vitro. Furthermore, cells of stressed Fhit-/- cell lines formed s.c. and metastatic tumors in nude mice. Collectively, we show that Fhit loss and subsequent thymidine kinase 1 inactivation, combined with selective pressures, leads to neoplasia-associated alterations in genes and gene expression patterns in vitro and in vivo.

Fragile Genes That Are Frequently Altered in Cancer: Players Not Passengers.

FHIT, located at FRA3B, is one of the most commonly deleted genes in human cancers, and loss of FHIT protein is one of the earliest events in cancer initiation. However, location of FHIT at a chromosomal fragile site, a locus prone to breakage and gap formation under even mild replication stress, has encouraged claims that FHIT loss is a passenger event in cancers. We summarize accumulated evidence that FHIT protein functions as a genome "caretaker" required to protect the stability of genomes of normal cells of most tissues from agents causing intrinsic and extrinsic DNA damage. FHIT loss leads to intracellular replication stress and subsequent genome instability, which provides an opportunistic mutational landscape in preneoplasias for selection of a variety of other cancer-driving mutations. We also review evidence showing that FHIT loss leads to enhanced activation of other common fragile sites, including the FRA16D/WWOX locus, and creates optimal single-stranded DNA substrates for the hypermutator enzyme, APOBEC3B.

DNA Repair Gene Polymorphisms and Their Relation With DNA Damage, DNA Repair, and Total Antioxidant Capacity in Childhood Acute Lymphoblastic Leukemia Survivors.

Oxidative stress and defective DNA repair are major contributory factors in the initiation and progression of carcinogenesis. Chemotherapy and radiotherapy cause oxidative DNA damage, consume antioxidant capacity, and impair DNA repair activity. These effects of chemotherapy and radiotherapy may be contributory factors in the development of secondary malignancy in cancer survivors. Basal, H2O2-induced, and postrepair DNA damage; urinary 8-hydroxydeoxyguanosine level as a marker of oxidatively damaged DNA; and serum total antioxidant capacity were measured; XPD Lys751Gln, XRCC1 Arg399Gln, and XRCC1 Arg194Trp polymorphisms were analyzed in childhood acute lymphoblastic leukemia (ALL) survivors. Basal and H2O2-induced DNA damage were found to be higher in the ALL survivor group versus the control group, however, there was no significant difference between the other parameters. No association was found between the examined parameters and polymorphisms of XPD 751 and XRCC1 399 and both the groups. XRCC1 194Trp allele was found to be associated with a low level of postrepair DNA damage in the ALL survivors. In conclusion, basal DNA damage and susceptibility to oxidation are high in childhood ALL survivors. This situation which may easily lead to occurrence of a secondary cancer does not seem to be a result of deficient DNA repair.

The drug-transporter gene MDR1 C3435T and G2677T/A polymorphisms and the risk of multidrug-resistant epilepsy in Turkish children.

One-third of all individuals with epilepsy are resistant to antiepileptic drug (AED) treatment. Antiepileptic treatment response has been suggested to be modulated by genetic polymorphisms of drug efflux transporters. Several polymorphic variants within the multidrug resistance 1 (MDR1) gene, which encodes the major transmembrane efflux transporter P-glycoprotein, have been proposed to be associated with AED resistance in epilepsy patients. The aim of this study was to evaluate the effect of C3435T and G2677T/A polymorphisms of MDR1 on AED resistance in Turkish children with epilepsy. MDR1 C3435T and G2677T/A were genotyped in 152 patients with epilepsy, classified as drug-resistant in 69 and drug-responsive in 83. Genotypes of the C3435T and G2677T/A polymorphisms were determined by polymerase chain reaction followed by restriction fragment length polymorphism. Genotype and allele frequencies of C3435T and G2677T/A polymorphisms of the MDR1 gene did not differ between drug-resistant and drug-responsive epilepsy patients. Our results suggest that MDR1 C3435T and G2677T/A polymorphisms are not associated with AED resistance in Turkish epileptic patients. To clarify the exact clinical implication of the MDR1 polymorphisms on the multidrug resistance in epilepsy, further investigations in various ethnic populations would be necessary.

Myxoma Virus Combination Therapy Enhances Lenalidomide and Bortezomib Treatments for Multiple Myeloma.

This study aimed to explore the effectiveness and safety of Myxoma virus (MYXV) in MM cell lines and primary myeloma cells obtained from patients with multiple myeloma. Myeloma cells were isolated from MM patients and cultured. MYXV, lenalidomide, and bortezomib were used in MM cells. The cytotoxicity assay was investigated using WST-1. Apoptosis was assessed through flow cytometry with Annexin V/PI staining and caspase-9 concentrations using ELISA. To explore MYXV entry into MM cells, monoclonal antibodies were used. Moreover, to explore the mechanisms of MYXV entry into MM cells, we examined the level of GFP-labeled MYXV within the cells after blocking with monoclonal antibodies targeting BCMA, CD20, CD28, CD33, CD38, CD56, CD86, CD117, CD138, CD200, and CD307 in MM cells. The study demonstrated the effects of treating Myxoma virus with lenalidomide and bortezomib. The treatment resulted in reduced cell viability and increased caspase-9 expression. Only low-dose CD86 blockade showed a significant difference in MYXV entry into MM cells. The virus caused an increase in the rate of apoptosis in the cells, regardless of whether it was administered alone or in combination with drugs. The groups with the presence of the virus showed higher rates of early apoptosis. The Virus, Virus + Bortezomib, and Virus + Lenalidomide groups had significantly higher rates of early apoptosis (p < 0.001). However, the measurements of late apoptosis and necrosis showed variability. The addition of MYXV resulted in a statistically significant increase in early apoptosis in both newly diagnosed and refractory MM patients. Our results highlight that patient-based therapy should also be considered for the effective management of MM.

The Long-Term Impact of Ionizing Radiation on DNA Damage in Patients Undergoing Multiple Cardiac Catheterizations.

Ionizing radiation (IR) exposures have increased exponentially in recent years due to the rise in diagnostic and therapeutic interventions. A number of small-scale studies investigated the long-term effect of IR on health workers or immediate effects of IR on patients undergoing catheterization procedures; however, the long-term impact of multiple cardiac catheterizations on DNA damage on a patient population is not known. In this study, the effects of IR on DNA damage, based on micronuclei (MN) frequency and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as markers in peripheral lymphocytes, were evaluated in patients who previously underwent multiple cardiac catheterization procedures. Moreover, genetic polymorphisms in genes PARP1 Val762Ala, OGG1 Ser326Cys, and APE1 Asn148Glu as a measure of sensitivity to radiation exposure were also investigated in the same patient population. The patients who underwent ≥ 3 cardiac catheterization procedures revealed higher DNA injury in comparison to the patients who underwent ≤ 2 procedures, documented with the presence of higher level of MN frequency (6.4 ± 4.8 vs. 9.1 ± 4.3, p = 0.002) and elevated serum 8-OHdG levels (33.7 ± 3.8 ng/mL vs. 17.4 ± 1.9 ng/mL, p = 0.001). Besides, OGG1 Ser326Cys and APE1 Asn148Glu heterozygous and homozygous polymorphic types, which are related with DNA repair mechanisms, were significantly associated with MN frequency levels (p = 0.006 for heterozygous and p = 0.001 for homozygous with respect to OGG1 Ser326Cys, p = 0.007 for heterozygous and p = 0.001 for homozygous with respect to APE1 Asn148Glu). There was no significant difference in terms of PARP1 Val762Ala gene polymorphism between two groups.

Patients with severe coronavirus disease 2019 have high frequency of factor 5 Leiden and prothrombin gene mutations.

We investigated the frequency of factor 5 Leiden (FVL) and prothrombin gene (PTG) mutations in patients with severe coronavirus disease 2019 (COVID-19). Our primary aim is to reveal whether these mutations are associated with severity of disease and mortality. A total of 249 patients were included in this cross-sectional study. Severe COVID-19 cases (with oxygen saturation of less than 90 mmHg and who received ventilation support invasively or noninvasively) were included. FVL and PTG mutations were identified by real time- PCR technique. Frequency of mutations for FVL was 11.7%, whereas for PTG was 3.5%. The frequency of FVL and PTG's mutations in our patient group was found to be significantly higher than the normal population ( P  < 0.0001, 0.004, respectively). There was no difference in the frequency of mutations of FVL and PTG between the patients ventilated - invasively and noninvasively. There was also no difference in D-dimer, ferritin, fibrinogen, ex status, and entubational status between the groups of FVL and PTG mutated and wild-type. To the best of our knowledge, it is the first time that we have examined the frequencies of FVL and PGM's mutations in severe COVID-19 disease on such a large scale. The frequencies of both mutations in severe COVID-19 patients were higher than in the healthy population. We believe that studies prospectively designed, including asymptomatic and mild COVID-19 patients, will provide more comprehensive information on the subject.

DNA repair XRCC1 Arg399Gln polymorphism is associated with the risk of development of end-stage renal disease.

Patients with end-stage renal disease (ESRD) display enhanced genomic damage. DNA repair gene polymorphisms may affect DNA repair capacity and modulate susceptibility to ESRD. In this study, we aimed to determine the frequency of polymorphisms in two DNA repair enzyme genes, Xeroderma pigmentosum complementation group D (XPD) and X-ray cross-complementing group 1 (XRCC1), in patients with ESRD and to evaluate their association with ESRD development. By using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), we genotyped four single nucleotide polymorphisms (SNPs) in XPD codons 312 and 751 and XRCC1 codons 194 and 399 in 136 dialysis patients (71 patients undergoing hemodialysis and 65 subjected to peritoneal dialysis) and 147 healthy controls. Patients having XRCC1 399 Arg/Gln (OR:1.98; 95% CI: 1.21-3.25, P = 0.007) or XRCC1-399 Gln/Gln (OR: 3.95; 95% CI: 1.45-10.76, P = 0.005) genotype had a significantly higher risk of ESRD than those with XRCC1 399 Arg/Arg genotype. We also found a significantly higher frequency of the XRCC1 399Gln allele in patients with ESRD than in controls, with OR = 2.03 (95% CI = 1.08-3.81, P = 0.03). We further investigated the potential combined effect of these DNA repair variants on the risk of ESRD development. It was found that combination of the Arg/Gln or Gln/Gln genotypes of XRCC1 Arg399Gln polymorphism with the two possible genotypes of XPD-Asp312Asn or with the Lys/Gln or Gln/Gln genotypes of XPD Lys751Gln was significantly associated with the development of ESRD. This is the first report showing an association between DNA repair gene polymorphisms and ESRD development, and suggests that XRCC1 Arg399Gln polymorphism may confer increased risk for the development of the disease. Further larger studies should be conducted to confirm these results.

Rheumatoid arthritis risk associates with DNA repair gene XRCC1 Arg399Gln polymorphism in Turkish patients.

Rheumatoid arthritis (RA) is an autoinflammatory disease with a genetic background. The synoviocytes in RA shows cellular transformation with tumor-like features, and RA patients have genomic instability and relaxation of DNA repair mechanisms. The polymorphisms in BER repair pathway genes, XRCC1 and OGG1, may change the response to inflammation via altered DNA repair capacity. In this study, we aimed to investigate the relationship between the risk of RA and XRCC1 Arg194Trp, Arg399Gln, and OGG1 Ser326Cys polymorphisms in a group of Turkish RA patients. XRCC1 Arg194Trp, Arg399Gln, and OGG1 Ser326Cys polymorphisms were investigated by PCR-RFLP method in 100 RA patients and 158 healthy control subjects. The results were statistically analyzed by calculating the odds ratios (OR) and their 95% confidence intervals (95% CI) using the χ(2)-tests. RA patients in this study had significantly higher frequencies of XRCC1 Arg399Gln polymorphism in both homozygote (GG) (35%, OR: 7.78 [95% CI: 3.65-16.59], P < 0.001) and heterozygote (AG) forms (41%, OR: 2.17 [95% CI: 1.19-3.96], P < 0.01) and also increased frequency of 399Gln (G) allele (55%, OR:2.99 [95% CI: 1.67-5.37], P < 0.001). We conclude that XRCC1 Arg194Trp, and OGG1 Ser326Cys polymorphisms are not associated with RA; however, Arg399Gln polymorphism is a significant risk factor of RA, and carriers of 399Gln (G) allele have greater risk of RA.

Association of XRCC3, XRCC4, BAX, and BCL-2 Polymorphisms with the Risk of Breast Cancer.

Background: Breast cancer is the most common malignancy in women. Genetic risk factors associated with breast cancer incidence have been identified. Aims: This study is aimed at determining the association of XRCC3 Thr241Met (rs861539), XRCC4 G(-1394) T (rs6869366) DNA repair and BAX G(-248) A (rs4645878), and BCL2 C(-938) A (rs2279115) apoptotic gene polymorphisms with breast cancer. Materials and Methods: Genetic analysis was performed using peripheral blood samples. Gene polymorphisms were detected by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. 175 patients and 158 healthy controls were enrolled in the study. Results: Breast cancer risk was 5.43 times more in individuals with AA genotype of Bax G(-248) A (rs4645878) (P = 0.002). The risk of metastasis was 11 times with this genotype. It was associated with 6 times more risk of having a tumor larger than 2 cm. The risk of breast cancer was 2.77 times more in individuals carrying the Met/Met genotype of XRCC3 Thr241Met (rs861539) (P = 0.009). The risk of having advanced clinical stage (stage III+IV) with the Met/Met genotype was 4 times more increased. No relationship with breast cancer was found with XRCC4 G(-1394) T (rs6869366) and BCL2 C(-938) A (rs2279115) gene polymorphisms. Conclusion: Multicenter trials using subjects with genetic variations are needed to establish the relationship between breast cancer and single gene polymorphism.

Glutathione S-transferase M1, GSTT1 and GSTP1 genetic polymorphisms and the risk of age-related macular degeneration.

PURPOSE: To determine the possible effects of glutathione S-transferase (GST) M1, GSTT1 and GSTP1 genetic polymorphisms on the risk of developing age-related macular degeneration (AMD). PATIENTS AND METHODS: This case-control study included a total of 120 patients with AMD (65 with dry-type AMD and 55 with wet-type AMD) and 198 disease-free controls. GSTM1 and GSTT1 polymorphisms were analyzed by using a multiplex polymerase chain reaction (PCR), and GSTP1 polymorphism was detected by real-time PCR assay. RESULTS: GSTM1-null genotype was significantly associated with the development of AMD (p = 0.01, OR = 1.82, 95% CI = 1.14-2.91). Stratification by AMD subtypes revealed a significant relationship between GSTM1-null genotype and dry-type AMD (p = 0.02, OR = 1.98, 95% CI = 1.10-3.53). In a stepwise regression model, only GSTM1-null genotype was significantly associated with the development of AMD (p = 0.01, OR = 1.77, 95% CI = 1.11-2.81). CONCLUSIONS: Our findings suggest that genetic polymorphisms of GST may have a role in the development of AMD.

DNA repair gene XRCC1 polymorphisms and the risk of asthma in a Turkish population.

Polymorphisms have been identified in several DNA damage repair genes. These polymorphisms may effect DNA repair capacity and modulate asthma susceptibility. In this study, we aimed to determine the two polymorphisms in DNA repair gene, x-ray repair cross-complementing group 1 (XRCC1), in a sample of Turkish patients with asthma, and evaluate their association with asthma development. We used polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) to analyze XRCC1 Arg194Trp and XRCC1 Arg399Gln polymorphisms in 116 patients with asthma and in 180 disease-free controls. Our data showed a positive association between the polymorphisms of codons 194 (odds ratio [OR] = 1.97, 95% confidence interval [CI] = 1.06-3.66, and p = 0.03 for Arg/Trp genotype) and 399 (OR = 1.87, 95% CI = 1.12-3.13, and p = 0.02 for Arg/Gln genotype, and OR = 2.59, 95% CI = 1.24-5.43, and p = 0.01 for Gln/Gln genotype) and asthma risk. No statistically significant difference was found for the allelic and genotypic distributions of the polymorphisms in XRCC1 gene between mild and moderate asthmatic patients. A combined analysis of the effect of XRCC1 codons 194 and 399 revealed the highest risk (OR = 4.17, 95% CI = 1.77-9.83, and p = 0.001) for carriers of the polymorphic alleles in both of these codons. These results suggest that the risk of asthma may be associated with DNA repair mechanisms, and understanding these mechanisms will help identify individuals at increased risk of developing asthma and should lead to improved treatment of asthma.

Association between genetic polymorphism in DNA repair genes and risk of B-cell lymphoma.

OBJECTIVES: The authors evaluated the possible effect of DNA repair genes, XPD (Xeroderma pigmentosum group D) codon (312 and 751) and XRCC1 (X-ray repair cross-complementing group 1) codon (194 and 399) SNPs (single-nucleotide polymorphisms) on the risk of childhood B-cell lymphoma. METHODS: The polymorphisms were analyzed in 33 patients with BL cases and in 52 healthy, age-matched controls using PCR-RFLP method. RESULTS: The authors observed no association between variation in the XPD codon Asp312Asn, Lys751Gln, and XRCC1 codon Arg399Gln polymorphisms and B-cell lymphoma for any parameter. In contrast, tryptophan allele frequency in control and patient groups was 0.10 and 0.03 respectively (p = .04). The frequency of XRCC1 194Arg/Trp genotype in B-cell lymphoma was significantly lower than that in controls (p = .005). No significant relationship was found between genotypes and stage, lactate dehydrogenase, or bone marrow involvement. CONCLUSIONS: XRCC1 194Trp allele may be associated with a protective effect against development of childhood B-cell lymphoma. However, these results were based on a small number of case and further studies should be done.

Altered methyltetrahydrofolate reductase gene polymorphism in mothers of children with attention deficit and hyperactivity disorder.

Attention Deficit and Hyperactivity Disorder (ADHD) is one of the most common psychiatric disorders in childhood and causes significant functional impairments in children. Behavioral genetic and molecular genetic studies have provided significant evidence in terms of highlighting the etiology of ADHD. Folate deficiency during pregnancy is an established risk factor for ADHD. Polymorphisms in the Methyltetrahydrofolate Reductase (MTHFR) encoding gene, such as A1298C and C667T, are associated with the decreased bioavailability of folate, and this condition can act like folate deficiency. In the literature, no study has investigated MTHFR polymorphisms in mothers of children with ADHD. Sixty-four children diagnosed with ADHD and their mothers as well as 40 healthy children and their mothers participated in this study. MTHFR polymorphisms were investigated in all participants. Comparison of the C677C and A1298C MTHFR polymorphisms in children with and without ADHD revealed no significant differences. We found that the maternal C677C_CT genotype counts, both observed and expected values, were significantly different from those based on Hardy-Weinberg Principle Analysis in the ADHD group. The most important result of this study was that maternal C677C MTHFR gene polymorphisms are significant risk factors in for ADHD, and we argue that children with ADHD are exposed to folate deficiency, even if their mothers received a sufficient amount of folate during pregnancy. This result also highlights one of the genetic factors of ADHD. Further studies should be performed to confirm this finding.

The role of TMPRSS6 gene variants in iron-related hematological parameters in Turkish patients with iron deficiency anemia.

TMPRSS6 gene mutations can result in iron deficiency anemia (IDA) and cause an increased iron-regulatory hormone, hepcidin, levels. TMPRSS6 encodes a serine protease, matriptase-2, which functions as negative regulatory protein of hepcidin transcription. Thus, TMPRSS6 variations might be risk factors for IDA. The aim of the study was to investigate the association of rs855791, rs4820268, rs5756506, rs2235324, rs2413450, rs2111833, rs228919, and rs733655 SNPs in TMPRSS6 gene with IDA susceptibility and iron-related clinical parameters. The study consisted of 150 IDA patients and 100 healthy controls. We analyzed the genotype distributions by using Real-Time polymerase chain reaction (Real-Time PCR) technique. We did not find any statistically differences for all SNPs between patients and controls (P > 0.05). In IDA patients, variations rs855791 and rs2413450 were associated with increased RBC (P = 0.03) and TIBC (P = 0.04), respectively. Also, increased of TIBC for rs4820268 (P < 0.05). On the other hand, in control group, rs5756506 was associated with two parameters, Hb (P = 0.02) and Hct (P = 0.03). We did not find markedly hepcidin levels in IDA patients compared to controls (P = 0.32). Our findings suggest that TMPRSS6 variations may not be risk factors for IDA. However, TMPRSS6 polymorphisms are associated with increased many iron-related hematological parameters.