Genome-wide analysis of gene expression after one year of venom immunotherapy.

Background Insect venom immunotherapy (VIT) is used to protect patients against Hymenoptera insects' venom allergy (HVA), which can result in severe systemic or even life-threatening conditions. Molecular mechanisms triggered by VIT remain largely unknown. Objective To compare genome-wide gene expression of patients with severe HVA prior to VIT and 12 months after. Methods Whole blood RNA samples were analyzed on an expression array. Results from differential expression obtained on a microarray platform were confirmed by quantitative real -time PCR (qRT-PCR). Subsequently we applied unsupervised clustering. Relative blood cell proportions and gene expression profiles were used as an input to csSAM to compute cell specific differential gene expression. Finally, transcription factor enrichment analysis was performed in MotifLab. Results & conclusions Comparison of genome-wide expression patterns for whole blood and qRT-PCR experiments revealed no significantly up and/or down regulated genes. This has been corroborated by unsupervised clustering. We found a significant upregulation of 26 genes in macrophages, of 15 genes in monocytes and 2 genes in T regulatory cells (Tregs). Analysis of the promoter sequences of these upregulated genes revealed a significant over-representation of binding motifs specific for kruppel-like factor 4, retinoic acid receptor gamma, and vitamin D receptor. Our results indicate that changes of gene expression invoked by VIT in peripheral blood may have a too small effect to be detected by conventional biostatistical approaches. When blood cell composition was taken into account we uncovered numerous changes of cell-specific gene expression. Given the regulatory implications we hypothesize that above-mentioned alterations may contribute to activation of anti-inflammatory signals in the innate branch of the immune system.

Multilevel omic data clustering reveals variable contribution of methylator phenotype to integrative cancer subtypes.

AIM: We aimed to assess to what extent CpG island methylator phenotype (CIMP) contributes to cancer subtypes obtained by multilevel omic data analysis. MATERIALS & METHODS: 16 The Cancer Genome Atlas datasets encompassing three data layers in 4688 tumor samples were analyzed. We identified cancer integrative subtypes (ISs) by the use of similarity network fusion and consensus clustering. CIMP high (CIMP-H) associated ISs were profiled by gene sets and transcriptional regulators enrichment analysis. RESULTS & CONCLUSION: In nine out of 16 cancer datasets CIMP-H clusters significantly overlaped with unique ISs. The contribution of CIMP-H on integrative molecular profiling is variable; therefore, only in a subset of cancer types does CIMP-H contribute to homogenous integrative subtype. CIMP-H associated ISs are heterogenous groups with regard to deregulated pathways and transcriptional regulators.

Phenotypic consequences of gene disruption by a balanced de novo translocation involving SLC6A1 and NAA15.

Mapping of de novo balanced chromosomal translocations (BCTs) in patients with sporadic poorly characterized disease(s) is an unbiased method of finding candidate gene(s) responsible for the observed symptoms. We present a paediatric patient suffering from epilepsy, developmental delay (DD) and atrial septal defect IIº (ASD) requiring surgery. Karyotyping indicated an apparently balanced de novo reciprocal translocation 46,XX,t(3;4)(p25.3;q31.1), whereas aCGH did not reveal any copy number changes. Using shallow mate-pair whole genome sequencing and direct Sanger sequencing of breakpoint regions we found that translocation disrupted SLC6A1 and NAA15 genes. Our results confirm two previous reports indicating that loss of function of a single allele of SLC6A1 causes epilepsy. In addition, we extend existing evidence that disruption of NAA15 is associated with DD and with congenital heart defects.

Immunological landscape of consensus clusters in colorectal cancer.

Recent, large-scale expression-based subtyping has advanced our understanding of the genomic landscape of colorectal cancer (CRC) and resulted in a consensus molecular classification that enables the categorization of most CRC tumors into one of four consensus molecular subtypes (CMS). Currently, major progress in characterization of immune landscape of tumor-associated microenvironment has been made especially with respect to microsatellite status of CRCs. While these studies profoundly improved the understanding of molecular and immunological profile of CRCs heterogeneity less is known about repertoire of the tumor infiltrating immune cells of each CMS. In order to comprehensively characterize the immune landscape of CRC we re-analyzed a total of 15 CRC genome-wide expression data sets encompassing 1597 tumors and 125 normal adjacent colon tissues. After quality filtering, CRC clusters were discovered using a combination of multiple clustering algorithms and multiple validity metrics. CIBERSORT algorithm was used to compute relative proportions of 22 human leukocyte subpopulations across CRC clusters and normal colon tissue. Subsequently, differential expression specific to tumor epithelial cells was calculated to characterize mechanisms of tumor escape from immune surveillance occurring in particular CRC clusters. Our results not only characterize the common and cluster-specific influx of immune cells into CRCs but also identify several deregulated gene targets that may contribute to improvement of immunotherapeutic strategies in CRC.

CYP1A1 Ile462Val polymorphism and colorectal cancer risk in Polish patients.

Colorectal cancer (CRC) is an epidemiological problem of a great importance in Poland; each year approximately 14,600 new cases of the disease are diagnosed. Mortality associated with CRC reaches approximately 10,400 cases per year (according to the National Cancer Registry). The 5-year survival rate is approximately 25 %, which is one of the lowest rates in Europe. The etiology of sporadic colorectal cancer (CRC) is multifactorial and has been attributed to an interplay between both environmental and genetic risk factors. In addition, there is a general consensus that genetic factors may modulate the influence of environmental insults. Following these assumptions, we performed a study on widely described polymorphisms in xenobiotic-metabolizing enzymes and DNA repair genes which may influence individual susceptibility to cancer. We selected five candidate polymorphisms in following genes: ERCC1 Asp118Asn (rs11615), XPC i11C/A (rs2279017), XRCC3 Met241Thr (rs861539) CYP1A1 Ile462Val (rs1048943) and NAT2 A803G (rs1208) and assessed the importance of chosen SNPs on groups consisting of 478 CRC patients and 404 controls. Only CYP1A1 Ile462Val was statistically significant in CRC patients over 50 years old: OR 2.05 (1.29-3.28); p = 1.25E-02 and this association was more pronounced in the female group of CRC patients after the age of 50: OR 2.72 (1.43-5.14); p = 1.14E-02.

[The role of genetic and environmental factors in the etiology of esophageal atresia and tracheo-esophageal fistula]. / Udzial czynników genetycznych i srodowiskowych w etiologii wrodzonego zarosniecia przelyku i przetoki tchawiczo-przelykowej

Esophageal atresia and tracheo-esophageal fistula are severe congenital malformations, whose etiology is still poorly understood. So far, numerous genetic and environmental factors that may contribute to the occurrence of these defects have been described and the literature is dominated by the view of their common involvement in the etiology and pathogenesis of congenital esophageal atresia. In this review the authors present current knowledge on the embryogenesis of the esophagus and trachea, discuss environmental risk factors, and also list and describe genetic alterations identified so far in patients with congenital esophageal atresia.

The C/A polymorphism in intron 11 of the XPC gene plays a crucial role in the modulation of an individual's susceptibility to sporadic colorectal cancer.

Epidemiological data show that colorectal cancer (CRC) is the second most frequent malignancy worldwide. The involvement of "minor impact genes" such as XME and DNA-repair genes in the etiology of sporadic cancer has been postulated by other authors. We focused on analyzing polymorphisms in DNA-repair genes in CRC. We considered the following genes involved in DNA-repair pathways: base excision repair (OGG1 Ser326Cys, XRCC1 Trp194Arg and Arg399Gln); nucleotide excision repair [XPA (-4)G/A, XPC C/A (i11) and A33512C (Lys939Gln), XPD Asp312Asn and A18911C (Lys751Gln), XPF Arg415Gln, XPG Asp1104His, ERCC1 C118T]; homologous recombination repair [NBS1 Glu185Gln, Rad51 135G/C, XRCC3 C18067 (Thr241Met)]. The study group consisted of 133 patients diagnosed with sporadic CRC, while the control group was composed of 100 age-matched non-cancer volunteers. Genotyping was performed by PCR and PCR-RFLP. Fisher's exact test with a Bonferroni correction for multiple testing was used. We found that: (i) XPC C/A (i11) heterozygous variant is associated with increased risk of CRC [OR is 2.07 (95% CI 1.1391, 3.7782) P=0.038], (ii) XPD A18911C (Lys751Gln) is associated with decreased risk of CRC [OR=0.4497, (95% CI 0.2215, 0.9131) P=0.031] for an individual with at least one A allele at this locus. (1) The XPC C/A (i11) genotype is associated with an increased risk of sporadic colorectal cancer. (2) The NER pathway has been highlighted in our study, as a most important in modulation of individual susceptibility to sCRC.

Detection of viral DNA sequences in sporadic colorectal cancers in relation to CpG island methylation and methylator phenotype.

There is evidence that insertion of viral DNA into a mammalian genome can lead to alterations of methylation patterns. The aim of the present study was to examine the presence of DNA sequences of five human DNA viruses (assessed by PCR): JC polyoma virus (JCV), human adenovirus (AdV), Epstein-Barr virus (EBV), Kaposi sarcoma-associated herpesvirus (KSHV/HHV8) and human papillomavirus (HPV) in a cohort of 186 sporadic colorectal cancers (CRCs) and related these data with the methylation status of six CpG island methylator phenotype (CIMP)-specific genes (MLH1, CACNA1G, NEUROG1, IGF2, SOCS1, RUNX3) and seven cancer-related genes markers (p16, MINT1, MINT2, MINT31, EN1, SCTR and INHBB) assessed by methylation-specific PCR in 186 and 134 CRC cases, respectively. The AdV, KSHV and HPV were detected in four (2%), two (1%) and zero CRC cases, respectively, and thus were excluded from further analyses. Although 19% and 9% of the CRCs were positive for EBV and JCV, respectively, no associations between virus presence and CpG island methylation were found after correction for multiple testing. Our results demonstrate that the presence of DNA sequences of JCV and EBV in CRC is unrelated to the methylation of the 13 cancer-related CpG islands and CIMP.

Irrelevance of CHEK2 variants to diagnosis of breast/ovarian cancer predisposition in Polish cohort.

CHEK2 gen encodes cell cycle checkpoint kinase 2 that participates in the DNA repair pathway, cell cycle regulation and apoptosis. Mutations in CHEK2 gene may result in kinase inactivation or reduce both catalytic activity and capability of binding other proteins. Some studies indicate that alterations in CHEK2 gene confers increase the risk of breast cancer and some other malignancies, while the results of other studies are inconclusive. Thus the significance of CHEK2 mutations in aetiology of breast cancer is still debatable. The aim of our study was to evaluate the relationship between the breast/ovarian cancer and CHEK2 variants by: i) the analysis of the frequency of selected CHEK2 variants in breast and ovarian cancer patients compared to the controls; ii) evaluation of relationships between the certain CHEK2 variants and clinico-histopathological and pedigree data. The study was performed on 284 breast cancer patients, 113 ovarian cancer patients and 287 healthy women. We revealed the presence of 430T > C, del5395 and IVS2 + 1G > A variants but not 1100delC in individuals from both study and control groups. We did not observe significant differences between cancer patients and controls neither in regard to the frequency nor to the type of CHEK2 variants. We discussed the potential application of CHEK2 variants in the evaluation of breast and ovarian cancer predisposition.

Progressive development of sonographic features in prenatal diagnosis of Apert syndrome--case report and literature review.

Apert syndrome is characterized by craniosynostosis, midfacial malformations and symmetrical syndactyly of the hands and feet. We report a case of prenatal sonographic diagnosis of Apert syndrome. Mild ventriculomegaly with normal head shape observed at 22 weeks gestation, followed by colpocephaly at 25 weeks gestation and bilateral syndactyly and subsequent craniosynostosis at 28 weeks, led to the prenatal diagnosis of Apert syndrome. The diagnosis was confirmed by physical examination and molecular study after birth. Additionally the authors present the review of literature on prenatal sonographic diagnosis of Apert syndrome.

Clinical and molecular-cytogenetic evaluation of a family with partial Jacobsen syndrome without thrombocytopenia caused by an approximately 5 Mb deletion del(11)(q24.3).

Clinical manifestations of Jacobsen syndrome (JBS) depend on the size of the 11qter deletion, which usually varies between approximately 7 and 20 Mb. Typical JBS features include developmental delay/mental retardation, short stature, congenital heart defects, thrombocytopenia, and characteristic dysmorphic facial features. We report on a family in which a 4-year-old girl as well as her mother and maternal uncle present with subtle features of JBS. Notably, neither thrombocytopenia nor congenital anomalies were detected in this family. Cytogenetic analyses revealed normal karyotypes. Using fluorescence in situ hybridization (FISH) and whole-genome oligonucleotide array CGH analyses, we identified an approximately 5 Mb deletion of the terminal part of chromosome 11q in all the three affected family members. The deletion breakpoint was mapped between 129,511,419 and 129,519,794 bp. This is the smallest deletion reported in a JBS patient. Interestingly, the FLI1 (friend leukemia virus integration 1) hematopoiesis factor gene located approximately 6.5 Mb from 11qter and usually deleted in patients with JBS, is intact. Our data support previous hypotheses that FLI1 haploinsufficiency is responsible for thrombocytopenia in patients with JBS.

Polymorphism in nucleotide excision repair gene XPC correlates with bleomycin-induced chromosomal aberrations.

Chromosomal aberrations (CAs) are important genetic alterations in the development and progression of the majority of human cancers. The frequency with which such alterations occur depends to a large extent on polymorphisms of DNA-repair genes and in genes coding for xenobiotic metabolizing enzymes, which are involved in the processes of activation and inactivation of xenobiotics. The frequency of bleomycin (BLM)-induced CAs is an indirect measure of the effectiveness of DNA repair mechanisms, and a predictor of environment-related risk of cancer. Our study was conducted on the human peripheral blood lymphocytes of 82 healthy volunteers. The aim of the study was to elucidate whether the frequency of BLM-induced CAs is correlated with polymorphisms of selected genes involved in different mechanisms of DNA repair such as: XRCC1 [base excision repair]; XPA, XPC, XPG, XPD, XPF, ERCC1 [nucleotide excision repair], NBS1, RAD51, XRCC2, XRCC3, RAD51, and BRCA1 [homologous recombination], as well as in genes encoding xenobiotic metabolizing enzymes, such as CYP1A, CYP2E1, NAT2, GSTT1, and EPHX (mEH). Our study indicated that, of the polymorphisms studied, only XPC (exon 15 and intron 11) is associated with BLM-induced CAs, suggesting a role of the NER pathway in the repair of BLM-induced chromosomal aberrations.

[Rapid-FISH--fast and reliable method of detecting common numerical chromosomal aberrations in prenatal diagnosis]. / Rapid-FISH jako szybka metoda wykrywania najczestszych liczbowych aberracji chromosomowych w diagnostyce prenatalnej u kobiet z grupy wysokiego ryzyka.

OBJECTIVE: In recent years, new possibilities of prenatal diagnosis have opened up, due to the development of techniques which guarantee shorter time of obtaining results. One of those methods, called Rapid-FISH (rapid fluorescence in situ hybridization), for detecting numerical aberrations of chromosomes 13, 18, 21, X and Y without culturing, enables to have the results in 2-5 days. The time necessary to obtain fetal karyotype result with the usage of the classical cytogenetic methods is about 2-3 weeks and depends mainly on the culture growth rate. DESIGN: The aim of the study was to evaluate the effectiveness of the Rapid-FISH technique in detecting numerical chromosome aberrations of 13, 21, 18, X and Y in amniocytes' nuclei from amniotic fluid. MATERIALS AND METHODS: Rapid-FISH and cytogenetic analysis has been performed for 161 pregnancies in the Department of Genetics at Wroclaw Medical University during years 2005 and 2006. The FISH was performed using AneuVysion kit (Vysis), according to a standard protocol. RESULTS: All normal and abnormal results were confirmed by classical cytogenetic method (GTG banding and karyotyping). Additional chromosomal aberrations, not possible to be detected in FISH, were observed in case of two patients with normal results from FISH analysis. CONCLUSIONS: Rapid-FISH is a reliable and fast method for detecting numerical chromosomal aberrations in prenatal diagnosis and should be implemented as a routine diagnostic procedure in pregnancies with high risk of fetal aneuploidy (of chromosomes 13, 18, 21, X i Y).

Influence of polymorphisms in xenobiotic-metabolizing genes and DNA-repair genes on diepoxybutane-induced SCE frequency.

Analysis of the combined effects of polymorphisms in genes encoding xenobiotic metabolizing enzymes (XMEs) and DNA repair proteins may be a key to understanding the role of these genes in the susceptibility of individuals to mutagens. In the present study, we performed an in vitro experiment on lymphocytes from 118 healthy donors that measured the frequency of diepoxybutane (DEB) induced sister chromatid exchanges (SCEs) in relation to genetic polymorphisms in genes coding for XMEs (CYP1A1, CYP2E1, GSTT1, EPHX, and NAT2), as well as DNA repair proteins (XRCC1, XRCC2, XRCC3, XPD, XPA, XPC, XPG, XPF, ERCC1, BRCA1, NBS1, and RAD51). We found that GSTT1(-) and CYP2E1 c1/c2 polymorphisms were associated with higher DEB-induced SCE frequencies, and that NAT2 G(590)A was associated with lower SCE induction by DEB. Analysis of the effect of pairs of genes showed that for a fixed GSTT1 genotype, the SCE level increased with an increasing number of Tyr alleles in EPHX codon 113. We found that among GSTT1(+) individuals the DEB-induced SCE level was significantly lower when the EPHX 139 codon was His/Arg rather than His/His. An interaction between polymorphisms in CYP2E1 and at EPHX codon 113 was also observed. The results of our study confirm observations in cancer patients and in people exposed to xenobiotics indicating that sensitivity to mutagens depends upon a combined effect of a variety of "minor impact" genes. Moreover, our results indicate that polymorphisms in genes coding for XMEs have a greater influence on the genotoxic activity of DEB, measured by DEB-induced SCE frequency, than polymorphisms in genes encoding DNA repair proteins.