DNA repair polymorphisms influence the risk of second neoplasm after treatment of childhood acute lymphoblastic leukemia

Purpose

Patients treated for childhood acute lymphoblastic leukemia (ALL) are considered to be at increased risk of developing second neoplasm. The aim of our study was to identify DNA repair polymorphisms contributing to the risk of second neoplasm in clinically well-characterized Slovenian patients treated for childhood ALL.

Methods

Pediatric patients diagnosed with ALL between 1971 and 2001 were included in the study. According to the identified clinical risk factors for second neoplasm, a matched set of cases with second neoplasm and controls was selected and genotyped for 11 DNA repair polymorphisms.

Results

Among 359 pediatric patients with ALL, 20 second neoplasms were observed. The dose of radiotherapy (P?=?0.011), administration of epipodophyllotoxins (P?=?0.006), and the dose of anthracyclines (P?<?0.001) showed a significant association with the risk of second neoplasm. Among genetic factors, we observed a significant association of NBN 1197G allele with increased risk of second neoplasms (RR?=?4.36; 95?% CI: 1.19–15.98; P?=?0.026), while the risk was decreased in carriers of XRCC3-316G allele compared with patients with wild-type genotype (RR?=?0.20; 95?% CI: 0.04–0.99; P?=?0.049).

Conclusions

Our results suggest an important role of NBN 1197A>G and XRCC3-316A>G polymorphisms in the development of second neoplasm in patients treated for childhood ALL.     

DNASE1L3 deficiency,new phenotypes,and evidence for a transient type I IFN signaling

Journal of Clinical Immunology - Deoxyribonuclease 1 like 3 (DNASE1L3) is a secreted enzyme that has been shown to digest the extracellular chromatin derived from apoptotic bodies, and DNASE1L3...     

Chemical composition of the ethanolic propolis extracts and its effect on HeLa cells

Ethnopharmacological relevance

Propolis is a resinous hive product collected by honeybees from various plant sources. It is widely used in traditional medicine and is reported to have a broad spectrum of pharmacological effects (antibacterial, antihepatoxic, antioxidative, anti-inflammatory, etc.). Thus the aim of this study was to assess cytotoxic effect of various ethanol propolis extractions on the cervical tumor cell line (HeLa) and compare it with their phenolic acids and flavonoids composition.

Materials and methods

Twenty samples of raw propolis were collected from 17 localities of Croatia (I-XVII), 2 of Bosnia and Hercegovina (XVIII, XIX) and 1 of Macedonia (XX). Reverse phase HPLC was used to determine the chemical composition of polyphenols. Biological experiments were carried out in vitro on cervix adenocarcinoma cell line (HeLa).

Results

Phenolic acids (ferulic acid, p-coumaric acid, caffeic acid) and flavonoids (tectochrysin, galangin, pinocembrin, pinocembrin-7-methylether, chrysin, apigenin, kaempferol, quercetin) have been determined using HPLC analysis in 20 ethanolic propolis extracts. All samples contain tectochrysin in ranges of 0.1988 mg/g (XVIII) to 1.2004 mg/g (III), while caffeic acid and quercetin have not been found. Flavonoid that is most abundant is galangin in ranges from 0.3706 mg/g (XVII) to 47.4879 mg/g (IX). The samples of propolis numbers I, VI and X applied in the investigated concentration range manifested significant reduction of cell growth. GI₅₀ value as indicator of cytotoxicity among propolis samples showed that propolis number VII is the most effective (GI₅₀ = 76 μg/ml) followed by propolis nos. XV, XVIII and I.

Conclusion

Antiproliferative and cytotoxic effect of propolis on the HeLa cells is not correlating with the concentration of particular components but on establishing the possible synergistic antiproliferative activity of individual phenolic acid and flavonoids. Differences in the chemical composition lead to diversity in biological activity of propolis samples.     

Correlation between AVPR2 mutations and urinary AQP2 excretion in patients with nephrogenic diabetes insipidus

Activation of the V2 receptor by arginine vasopressin (AVP) results in trafficking of the water channel AQP2 to the luminal plasma membrane and a small amount into the urine. Mutations in the A VPR2 gene, encoding the AVP V2 receptor, result in congenital nephrogenic diabetes insipidus (CNDI). To determine a correlation between A VPR2 mutations and urinary AQP2 excretion, immunobloting was used to detect AQP2 in the urine of patients with CNDI before and after a dehydration test. The patients' genotype was determined using PCR amplification and direct sequencing of the complete A VPR2 gene. Urinary AQP2 excretion was absent in patients with severely debilitating mutations, a novel total deletion of the A VPR2 gene, and a novel nonsense mutation W296X. However, it was detected in siblings with a V88M missense mutation. Urinary AQP2 excretion correlated well with other tested phenotype markers. Urinary AQP2 excretion could be used to evaluate the remaining in vivo integrity of the AVP-V2 receptor-AQP2 cascade in patients with CNDI.     

Genetic analysis of 39 erythrocytosis and hereditary hemochromatosis‐associated genes in the Slovenian family with idiopathic erythrocytosis

BackgroundErythrocytosis is a condition with an excessive number of erythrocytes, accompanied by an elevated haemoglobin and/or haematocrit value. Congenital erythrocytosis has a diverse genetic background with several genes involved in erythropoiesis. In clinical practice, nine genes are usually examined, but in approximately 70% of patients, no causative mutation can be identified. In this study, we screened 39 genes, aiming to identify potential disease‐driving variants in the family with erythrocytosis of unknown cause.Patients and MethodsTwo affected family members with elevated haemoglobin and/or haematocrit and negative for acquired causes and one healthy relative from the same family were selected for molecular‐genetic analysis of 24 erythrocytosis and 15 hereditary haemochromatosis‐associated genes with targeted NGS. The identified variants were further analysed for pathogenicity using various bioinformatic tools and review of the literature.ResultsOf the 12 identified variants, two heterozygous variants, the missense variant c.471G>C (NM_022051.2) (p.(Gln157His)) in the EGLN1 gene and the intron variant c.2572‐13A>G (NM_004972.3) in the JAK2 gene, were classified as low‐frequency variants in European population. None of the two variants were present in a healthy family member. Variant c.2572‐13A>G has potential impact on splicing by one prediction tool.ConclusionFor the first time, we included 39 genes in the erythrocytosis clinical panel and identified two potential disease‐driving variants in the Slovene family studied. Based on the reported functional in vitro studies combined with our bioinformatics analysis, we suggest further functional analysis of variant in the JAK2 gene and evaluation of a cumulative effect of both variants.     

Genetic variability of hypoxia‐inducible factor alpha (HIFA) genes in familial erythrocytosis: Analysis of the literature and genome databases

Familial erythrocytosis (FE) is a congenital disorder, defined by elevated red blood cell number, hemoglobin, and hematocrit. Among eight types of FE, type 4 is caused by variants in the EPAS1 gene. Two other hypoxia‐inducible factor alpha (HIFA) subunits, HIF1A and HIF3A, have not yet been associated with medical history of FE, but have potential role in the development of erythrocytosis. To improve diagnosis, it is crucial to identify new variants in genes involved in erythrocyte production. Published literature and data from genome browsers were used to obtain HIFA sequence variants associated with erythrocytosis and to locate them on protein sequence and regulatory sites. We retrieved 24 variants from the literature: 2 in HIF1A, 20 in EPAS1 and 2 in HIF3A gene. Sixteen out of 20 variants in the EPAS1 gene are positioned in a conserved region of 13 amino acids within exon 12, next to regulatory post‐translational modification and binding sites, suggesting that EPAS1 has an important role in erythropoiesis. The role of HIF1A and HIF3A in the development of erythrocytosis should be further investigated.