Project description:Polyamines are aliphatic polycations that have emerged as important determinants of cell growth and viability in rapidly proliferating cells, including in the pathogenic protozoan parasite Leishmania donovani. In L. donovani, the polyamine spermidine is synthesized by the successive conversion of ornithine into putrescine (catalyzed by ornithine decarboxylase or ODC) and putrescine into spermidine (catalyzed by spermidine synthase or SPDSYN). Deletion of either ODC (del-odc) or SPDSYN (del-spdsyn) from the L. donovani genome renders these parasites auxotrophic for polyamines and these mutants are impaired in their ability to survive both in culture and within the mammalian host without the addition of exogenous polyamine supplementation. Significantly, del-odc parasites immediately cease proliferation after putrescine is removed from the culture media and perish within two weeks, while spermidine starved del-spdsyn mutants, which retain intracellular putrescine pools, show a slow-growth phenotype, and persist for several weeks in culture. To elucidate the key differences within the proteome of putrescine-starved del-odc cells and spermidine-starved del-spdsyn parasites, a shotgun quantitative proteomics approach was undertaken using TMT labeling and LC-MS/MS analysis. Briefly, three biological replicates each for mid-log phase del-odc and del-spdsyn promastigotes grown in the presence of exogenous putrescine (for del-odc) or spermidine (for del-spdsyn) supplementation were washed to remove the exogenous polyamine supplementation and incubated in polyamine-free media. At 24 and 48 h, cells from each biological replicate were isolated and prepared for tandem mass tag (TMT) labeling and downstream LC-MS/MS analyses. Peptides were identified using a database generated from the reference genome of L. donovani BPK282A1 strain. Changes in relative protein abundance for the polyamine-starved del-odc and del-spdsyn cell lines at 24 and 48 h were calculated by comparing aggregate total reporter ion intensities for each protein to that of the corresponding polyamine-supplemented 0-h timepoint.
Project description:Cytogenetics abnormalities (CA) are known to be the preponderant prognostic factor in multiple myeloma (MM). Our team has recently developeda prognostic score based on 6 CA, where del(1p32) appears to be the second worst abnormality after del(17p). The aim of this study was to confirm the adverse impact of 1p32 deletion on newly-diagnosed multiple myeloma (NDMM) patients. Among 2551 NDMM patients, 11% were harboring del(1p32). Their overall survival (OS) was half as long as the OS of patients without del(1p32) (49 months vs. 124 months). Likewise, progression-free survival was significantly shorter. More importantly, double-deletion of the 1p32 locus conferred a dramatically poorer prognosis than a monoallelic del(1p32) (OS: 25 months vs. 60 months). As expected, the OS of del(1p32) patients significantly decreased when this abnormality was associated with other high-risk CA (del(17p), t(4;14) or gain(1q)). In the multivariate analysis, del(1p32) appeared as a negative prognostic factor; after adjustment for age and treatment, the risk of progression was 1.3 times higher among patients harboring del(1p32), and the risk of death was 1.9 times higher. At the dawn of risk-adapted treatment strategies, we have confirmed the adverse impact of del(1p32) in MM and the relevance of its assessment at diagnosis.
Project description:Cytogenetic profiles of 50 meningiomas using high-density GeneChip Mapping 500K set and Genome-Wide Human SNP 6.0 Array in the tumor tissues and in the peripheral blood of the same patients. A total of two hundred 500k arrays (100 tumor samples and 100 blood samples) and 14 SNP6.0 arrays (7 tumour samples and 7 peripheral blood samples) were studied to explore the most common recurrent chromosomal abnormalities (gains and losses) in meningiomas. Our results confirm that del(22q) (52%) and del(1p) (16%) (common deleted regions: 22q11.21-22q13.3. and 1p31.2-p36.33) are the most frequent abnormalities. Additionally, recurrent monosomy 14 (8%), del(6p) (10%), del(7p) (10%) and del(19p) (6%) were also observed, while copy number variation (CNV) patterns consistent with recurrent chromosome gains, gene amplification was absent or rare. Based on their overall SNP profiles meningiomas could be classified into: i) diploid cases, ii) meningiomas with a single chromosome change (e.g. monosomy 22/del(22q) and iii) tumours with ≥2 altered chromosomes.
Project description:Marginal zone B-cell lymphomas (MZL) have been divided into three distinct subtypes (extranodal MZL of MALT type, nodal MZL; splenic MZL). Nevertheless, the relationship between them is still unclear. We performed a comprehensive analysis of genomic DNA copy number changes in a very large series of MZL cases with the aim of addressing this question. Samples from 218 MZL patients (25 nodal, 57 MALT, 134 splenic and two not better specified MZL) were analyzed with the Affymetrix Human Mapping 250K SNP arrays, and the data combined with matched gene expression in 33/218 cases. MALT lymphoma presented significantly more frequently gains at 3p, 6p, 18p and del(6q23) (TNFAIP3/A20), whilst splenic MZL was associated with del(7q31), del(8p). Nodal MZL did not show statistically significant differences when compared with MALT lymphoma while lacked the splenic MZL-related 7q losses. Gains of 3q and 18q gains were common to all three subtypes. Del(8p) was often present together with del(17p) (TP53). While del(17p) did not determine a worse outcome and del(8p) was only of borderline significance, the presence of both deletions had a highly significant negative impact on the outcome of splenic MZL.
Project description:High-resolution genomic microarrays provides simultaneous detection of copy-number aberrations such as the known recurrent aberrations in Chronic Lymphocytic Leukemia_diagnostic sample_patient (del(11q), del(13q), del(17p) and trisomy 12), and copy-number neutral loss of heterozygosity. We screened 369 newly diagnosed Chronic Lymphocytic Leukemia_diagnostic sample_patient patient samples from a population-based cohort using 250K single nucleotide polymorphism-arrays.
Project description:Using high-resolution array comparative genomic hybridization, we mapped del(14)(q) in a series of 23 B-cell leukemia/lymphoma cases. Interestingly, 14 cases with interstitial del(14)(q) showed involvement of IGH at 14q32.33. Whereas the proximal breakpoints of these deletions varied in 6 cases, they clustered in the 14q24.1/ZFP36L1 region in the 8 remaining cases. The latter del(14)(q24.1q32.33) covering approximately 36 Mb was further demonstrated in 12 additional patients by FISH. The majority of cases harboring this deletion were diagnosed as chronic lymphocytic leukemia (CLL) (75%), particularly atypical CLL, and were frequently associated with trisomy 12 (40%) and unmutated VH region (75%). Further analysis of the 14q32.33 breakpoints showed clustering in the constant region of IGH, proximal to the 5’ (Eµ) enhancer sequences. These findings therefore suggest that the del(14)(q24.1q32.33), and other analogous IGH-involving del(14)(q), might represent a novel aberration leading to activation of unknown oncogene(s) at 14q by its juxtaposition with regulatory elements of IGH. Extensive expression analysis via quantitative PCR and microarray profiling, however, failed to identify a gene uniformly upregulated in cases with del(14)(q24.1q32.33). Further investigations are needed to unravel the mechanism(s) and role of IGH-involving del(14)(q) in B-cell malignancies. Keywords: comparative genomic hybridization
Project description:Japanese quail (Coturnix coturnix japonica) reach sexual maturity early, breed rapidly and successfully, and cost less and require less space than other birds raised for their meat and eggs. Given the value of this species for commercial production and experimental use as well as recent increasing demand, more studies are necessary to determine chromosomal regions and genes associated with gender and breed-differentiation in the species. Identification of sex-related genes can help target chromosomal regions for molecular sexing purposes. This study employed Trinity and edgeR for transcriptome analysis of next-generation RNA-seq data, which included 4 tissues obtained from 3 different breeds of Japanese quail (wild, miniature, and jumbo). The initial goal was to identify genes related to sexual dimorphism, as well as potential novel candidate genes for molecular sexing. Analysis and interpretation of differentially expressed genes shared between female and male tissue contrast groups provided insight into sex-related differences. Several of the genes identified in the present study as significant sex-related genes have been previously found in avian gene expression analyses (e.g. NIPBL, UBAP2), and other genes found differentially expressed in this study and not previously associated with sex-related differences may be considered potential candidates for molecular sexing (e.g. TERA, MYP0, PPR17, CASQ2). Additionally, other genes likely associated with neuronal and brain development (e.g. CHKA, NYAP), as well as body development and size differentiation (e.g. ANKRD26, GRP87) in quail were identified. Expression of homeobox protein regulating genes in the sex-related contrast group revealed two genes (HXC4, ISL1) that may regulate sex-specific anatomical development. Results of these analyses expand the currently limited pool of knowledge on the genetic features of the quail breed and could allow for more effective molecular sexing as well as selective breeding for traits important in commercial production.
Project description:Aberrant DNA methylation is a hallmark of cancer but mechanisms contributing to the abnormality remain elusive. Here, we report that most of lung cancer cell lines tested expressed predominantly ∆DNMT3B-del whereas normal bronchial epithelial cells expressed equal quantities of ∆DNMT3B and ∆DNMT3B-del. We demonstrate biological impacts of ∆DNMT3B4-del, a ∆DNMT3B-del isoform, in a transgenic mouse model. Expression of ∆DNMT3B4-del in the mouse lungs resulted in an increased global DNA hypomethylation, focal DNA hypermethylation, epithelial hyperplastia and tumor formation when challenged with a tobacco carcinogen. In patients with non-small cell lung cancer, 83% of the primary tumors expressed predominantly ∆DNMT3B-del. Our results demonstrate ∆DNMT3B4-del as a critical factor in developing aberrant DNA methylation during lung tumorigenesis.
Project description:Koolen-de Vries syndrome (KdVS) is a multi-system disorder characterized by intellectual disability, friendly behavior, and congenital malformations. The syndrome is caused either by microdeletions in the 17q21.31 chromosomal region or by variants in the KANSL1 gene. The reciprocal 17q21.31 microduplication syndrome is associated with psychomotor delay, and reduced social interaction. To investigate the pathophysiology of 17q21.31 microdeletion and microduplication syndromes, we generated three mouse models: 1) the deletion (Del/+); or 2) the reciprocal duplication (Dup/+) of the 17q21.31 syntenic region; and 3) a heterozygous Kansl1 (Kans1+/-) model. We found altered weight, general activity, social behaviors, object recognition, and fear conditioning memory associated with craniofacial and brain structural changes observed in both Del/+ and Dup/+ animals. By investigating hippocampus function, we showed synaptic transmission defects in Del/+ and Dup/+ mice. Mutant mice with a heterozygous loss-of-function mutation in Kansl1 displayed similar behavioral and anatomical phenotypes compared to Del/+ mice with the exception of sociability phenotypes. Genes controlling chromatin organization, synaptic transmission and neurogenesis were upregulated in the hippocampus of Del/+ and Kansl1+/- animals. Our results demonstrate the implication of KANSL1 in the manifestation of KdVS phenotypes and extend substantially our knowledge about biological processes affected by these mutations. Clear differences in social behavior and gene expression profiles between Del/+ and Kansl1+/- mice suggested potential roles of other genes affected by the 17q21.31 deletion. Together, these novel mouse models provide new genetic tools valuable for the development of therapeutic approaches.