Screening of polymorphisms in the folate pathway in Turkish pediatric Acute Lymphoblastic Leukemia patients

Background and aim: Folate metabolic pathway plays a significant role in leukemogenesis because of its necessity for nucleotide synthesis and DNA methylation. Folate deficiency causes DNA damage. Thus polymorphisms of folate-related genes may affect the susceptibility to childhood Acute Lymphoblastic Leukemia (ALL). MTHFR (Methylenetetrahydrofolate Reductase), DHFR (Dihydrofolate reductase), CBS (Cystathionine b-synthase) and TYMS (Thymidylate Synthase) have an important role in folate pathway because their activated variants modulate synthesis of DNA and levels of folate. In this study, we aimed to investigate whether polymorphisms in genes related to folate metabolic pathway influence the risk to childhood ALL.Subject and methods: The patient groups who were diagnosed with childhood ALL at Losante Pediatric Hematology-Oncology Hospital and healthy control groups were included in the study. MTHFR 677 CT, MTHFR 1298 A-C, CBS 844ins68, DHFR 19-bp and TYMS 1494del6 polymorphisms were screened. Genotyping of these polymorphisms was performed by Restriction Fragment Length Polymorphism (RFLP) analysis and Real Time Polymerase chain Reaction (Real Time-PCR).Results: In total, we have screened 5 polymorphisms in the studied genes. The results were compared between childhood ALL patients and healthy groups. Genotype frequencies of MTHFR 677 C-T, MTHFR 1298 A-C, CBS 844ins68 and DHFR 19-bp del were similar for childhood ALL patients and healthy groups. However, statistical results showed that TYMS 1494del6 may be associated with ALL pathogenesis (p < 0.001).Conclusion: We showed that TYMS polymorphism (rs2853542) may be associated with ALL pathogenesis. In addition, our results demonstrated that MTHFR, DHFR and CBS do not affect development of leukemia. Our study displays also importance as it is the first screening results to identify association with the studied polymorphisms in Turkish patients with childhood ALL and determination of the frequency in Turkish population

Comparative Analysis of the Mutation and Expression Profile of the Cytoprotective NRF2/ KEAP1/P62/SQSTM1 Signaling Pathway in Different Glioma Subtypes: An In Silico Study

Aim:The NRF2/KEAP1/p62/SQSTM1 pathway is the master regulator of antioxidant enzymes and detoxification proteins, both of which play a critical role in redox homeostasis. It shows that the this structurally active pathway has a crucial role in cancer as it inhibits tumorigenesis and metastatic processes and it induces pro-survival genes that promote chemoresistance. The relationship between the molecular mechanisms causing the pathway to malfunction and the development of brain tumors has yet to be fully clarified. The aim of this study is to analyze the genetic changes and expression level differences of the NRF2/KEAP1 pathway comparatively in low-grade gliomas (LGG) and glioblastoma multiforme (GBM) pathology.Materials and Methods:Gene expression profiles and DNA sequences of GBM (n=591) and LGG (n=511) patients and healthy tissue were downloaded from the TCGA database. Not only were gene expression and mutation patterns determined in this study, but also the impacts of genes on survival were assessed. PolyPhen-2 and SNAP tools were used to estimate the pathogenic properties of the changes identified.Results:A total of 16 mutations and gene amplification were identified in the KEAP1, NRF2, p62/SQSTM1, HMOX-1, and MOAP1 for both cancer groups, and the mutation carrying frequency was 4.6%. IDH1 p.R132H and NRF2 p.S164* mutation association was determined in 1 patient with LGG. KEAP1, NRF2, and HMOX1 expression levels for both LGG and GBM subtypes were determined to be high in patient samples compared to healthy samples (p<0.05).Conclusion:By targeting the NRF2/KEAP1/p62/SQSTM1 pathway anomalies, new therapeutic approaches can be provided in the treatment of glioma, particularly for chemotherapy sensitivity

Detection of TET2, KRAS and CBL variants by Next Generation Sequencing and analysis of their correlation with JAK2 and FLT3 in childhood AML

Background: Acute myeloid leukemia (AML) is a heterogeneous clonal disorder in terms of cytogenetic and molecular aberrations. Ten-Eleven-Translocation 2 (TET2), Kirsten rat sarcoma viral oncogene homolog (KRAS), and Casitas B-cell lymphoma (CBL) have an important role pathogenesis of acute myeloid leukemia (AML) and their activated mutations confer proliferative and survival signals. Aim: In this study, we aimed to find possible genetic markers for molecular analysis in childhood AML by screening hot-spot exons of TET2, KRAS, and CBL using Next Generation Sequencing (NGS) analysis. In addition, association between found variants and mutations of Januse Kinase-2 (JAK2) and Fms-Related Tyrosine Kinase (FLT3) were analyzed which are important prognostic risk factors for AML. Methods: Eight patients who were diagnosed with pediatric AML at Losante Pediatric Hematology–Oncology Hospital were included to the study. Hot-spot exons of TET2, KRAS and CBL genes were screened using the NGS method. Furthermore, FLT3-Internal Tandem Duplicate (FLT3-ITD) and JAK2-V617F were analyzed by Real Time Polymerase chain Reaction (Real Time-PCR). Results: In total, we identified 20 variants in studied genes by NGS. In our patient group, 16 variants in the TET2 (seven novel, seven missense and two silent), two variants in the KRAS (one missense and one intronic) and two variants in the CBL (two novel) were found. All of AML patients were found negative for JAK V617 F. Three of the eight patients (37.5%) showed mutations of both FLT3-ITD and TET2, KRAS, CBL. Conclusion: We found novel mutations for TET2, KRAS, and CBL. The detected variants in this article seem to be the first screening results of genes studied by NGS in childhood AML patients. Our results also showed some degree of association between FLT3-ITD and TET2, KRAS, CBL mutations

Etiological agents of community-acquired pneumonia in adult patients in Turkey; a multicentric, cross-sectional study

This cross-sectional study was intended to investigate the etiology of community-acquired pneumonia (CAP) in adult patients receiving no prior antibiotic therapy. Etiological agents were identified in 137 (62.8%) of 218 patients, the most frequent being Streptococcus pneumoniae (14.7%), Mycoplasma pneumoniae (13.8%) and respiratory syncytial virus (10.1%). A single pathogen was detected in 50.9% of cases and mixed pathogens in 11.9%. Typical pathogens were determined in 35.8% of cases, atypical pathogens in 20.2% and viral pathogens in 20.6%. Chronic obstructive pulmonary disease was a common (42.7%) comorbidity. S. pneumoniae was the most common pathogen in adult patients with CAP. Atypical pathogens were more common in patients < 65 years old, M. pneumoniae being the most common in this age group. Our results suggest that initial empiric antibiotic treatment in patients with CAP should cover S. pneumoniae and M. pneumoniae in Turkey

Etiological agents of community-acquired pneumonia in adult patients in Turkey; a multicentric, cross-sectional study

This cross-sectional study was intended to investigate the etiology of community-acquired pneumonia (CAP) in adult patients receiving no prior antibiotic therapy. Etiological agents were identified in 137 (62.8%) of 218 patients, the most frequent being Streptococcus pneumoniae (14.7%), Mycoplasma pneumoniae (13.8%) and respiratory syncytial virus (10.1%). A single pathogen was detected in 50.9% of cases and mixed pathogens in 11.9%. Typical pathogens were determined in 35.8% of cases, atypical pathogens in 20.2% and viral pathogens in 20.6%. Chronic obstructive pulmonary disease was a common (42.7%) comorbidity. S. pneumoniae was the most common pathogen in adult patients with CAP. Atypical pathogens were more common in patients < 65 years old, M. pneumoniae being the most common in this age group. Our results suggest that initial empiric antibiotic treatment in patients with CAP should cover S. pneumoniae and M. pneumoniae in Turkey