2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has a large number of biological effects, including skin, cardiovascular, neurologic disease, diabetes, infertility and cancer. We analysed the in vitro TCDD effects on human CD34+ cells and tested the gene expression modulation by means of microarray analyses before and after TCDD exposure. We identified 253 differentially modulated probe sets, identifying 217 well-characterized genes. A large part of these were associated with cell adhesion and/or angiogenesis and with transcription regulation. Synaptic transmission and visual perception functions, with the particular involvement of the GABAergic pathway, were also significantly modulated. Numerous transcripts involved in cell cycle or cell proliferation, immune response, signal transduction, ion channel activity or calcium ion binding, tissue development and differentiation, female or male fertility or in several metabolic pathways were also affected after dioxin exposure. The transcriptional profile induced by TCDD treatment on human CD34+ cells strikingly reproduces the clinical and biological effects observed in individuals exposed to dioxin and in biological experimental systems.
Dioxin exposure of human CD34+ hemopoietic cells induces gene expression modulation that recapitulates its in vivo clinical and biological effects.
Specimen part, Treatment
View SamplesWe used microarrays to compared gene re-expression of SMARCB1 in I2A SMARCB1-deficient rhabdoid tumor cell line.
High-Throughput Drug Screening Identifies Pazopanib and Clofilium Tosylate as Promising Treatments for Malignant Rhabdoid Tumors.
Specimen part
View SamplesA SNP microarray and FISH-based procedure to detect allelic imbalances in multiple myeloma: an integrated genomics approach reveals a wide dosage effect on gene and microRNA expression
A SNP microarray and FISH-based procedure to detect allelic imbalances in multiple myeloma: an integrated genomics approach reveals a wide gene dosage effect.
Specimen part, Disease
View SamplesMultiple myeloma (MM) is characterized by marked genomic instability. Beyond structural rearrangements, a relevant role in its biology is represented by allelic imbalances leading to significant variations in ploidy status. To better elucidate the genomic complexity of MM, we analyzed a panel of 45 patients using combined FISH and microarray approaches. Using a self-developed procedure to infer exact local copy numbers for each sample, we identified a significant fraction of patients showing marked aneuploidy. A conventional clustering analysis showed that aneuploidy, chromosome 1 alterations, hyperdiploidy and recursive deletions at 1p and chromosomes 13, 14 and 22 were the main aberrations driving samples grouping. Then, we integrated mapping information with gene and microRNAs expression profiles: a multiclass analysis of the identified clusters showed a marked gene-dosage effect, particularly concerning 1q transcripts, also confirmed by correlating gene expression levels and local copy number alterations. A wide dosage effect affected also microRNAs, indicating that structural abnormalities in MM closely reflect in their expression imbalances. Finally, we identified several loci in which genes and microRNAs expression correlated with loss-of-heterozygosity occurrence. Our results provide insights into the composite network linking genome structure and gene/microRNA transcriptional features in MM.
A SNP microarray and FISH-based procedure to detect allelic imbalances in multiple myeloma: an integrated genomics approach reveals a wide gene dosage effect.
Specimen part, Disease
View SamplesB-cell chronic lymphocytic leukemia (B-CLL) is characterized by a highly variable clinical course that reflects its heterogeneous genomic pattern. To better define molecular subtypes of the disease, we performed SNP and gene expression profiling microarray analyses in a panel of early stage (Binet A) patients. A clustering analysis of genomic profiles identified four significant groups mainly driven by del(13)(q14) and trisomy 12. Notably, patients with del(13)(q14) were grouped in two separate clusters based on the presence of a biallelic loss and the extension of the deletion. The shorter monoallelic deleted 13q14 region was found to be 635 kb in length, not encompassing the mir-15a/16-1 locus. Interestingly, the mir-15a and mir-16 expression was found to be significantly down-regulated only in patients with biallelic loss. Furthermore, a multiclass supervised analysis identified a different transcriptional signatures in the two genomic subgroups with del(13)(q14). Finally, an integrative approach identified 93 transcripts, mainly mapped to chromosome 12 and 13q12-q14.3, whose expression was significantly correlated with the DNA copy number. Overall, our data further support the notion that transcription deregulation in B-CLL could be mostly due to a gene dosage effect and underscore the presence of two distinct molecular types of 13q14 deleted patients with potential clinical relevance.
Integrative genomics analyses reveal molecularly distinct subgroups of B-cell chronic lymphocytic leukemia patients with 13q14 deletion.
Sex, Specimen part, Disease
View SamplesDistinct genetic abnormalities such as TP53 deletion at 17p13.1, have been identified as having an adverse prognostic relevance in B-cell chronic lymphocytic leukemia (B-CLL). Conventional cytogenetic studies have shown that TP53 deletion in B-CLL is associated predominantly with 17p loss resulting from complex chromosomal rearrangements. We performed genome-wide DNA (SNPs arrays), fluorescence in situ hybridization (FISH) and gene expression profiling (GEP) analyses to investigate the significance of 17p loss in a panel of 71 genetically well-characterized B-CLLs in Binet stage A, 18 of which carried a TP53 monoallelic deletion. Combined SNP arrays and FISH approaches showed 17p loss in all of the TP53-deleted cases, with breakpoints scattered along the 17p11.2 region. Mutations in exons 5 to 9 of TP53 were found in 9/12 deleted samples. GEP of 60 B-CLLs, including 7 patients with 17p loss, identified 40 differentially expressed genes in 17p- versus 17p normal samples, 35 of which were down-regulated in 17p- tumors. The majority (30/35) of these transcripts, including putative tumor suppressor genes, mapped to 17p. Overall, these data indicate that, beside TP53 deletion, the concomitant loss of 17p arm may contribute to the strong negative prognostic impact known to be associated with this lesion in B-CLL.
Molecular and transcriptional characterization of 17p loss in B-cell chronic lymphocytic leukemia.
Sex
View SamplesDistinct genetic abnormalities such as TP53 deletion at 17p13.1, have been identified as having an adverse prognostic relevance in B-cell chronic lymphocytic leukemia (B-CLL). Conventional cytogenetic studies have shown that TP53 deletion in B-CLL is associated predominantly with 17p loss resulting from complex chromosomal rearrangements. We performed genome-wide DNA (SNPs arrays), fluorescence in situ hybridization (FISH) and gene expression profiling (GEP) analyses to investigate the significance of 17p loss in a panel of 71 genetically well-characterized B-CLLs in Binet stage A, 18 of which carried a TP53 monoallelic deletion. Combined SNP arrays and FISH approaches showed 17p loss in all of the TP53-deleted cases, with breakpoints scattered along the 17p11.2 region. Mutations in exons 5 to 9 of TP53 were found in 9/12 deleted samples. GEP of 60 B-CLLs, including 7 patients with 17p loss, identified 40 differentially expressed genes in 17p- versus 17p normal samples, 35 of which were down-regulated in 17p- tumors. The majority (30/35) of these transcripts, including putative tumor suppressor genes, mapped to 17p. Overall, these data indicate that, beside TP53 deletion, the concomitant loss of 17p arm may contribute to the strong negative prognostic impact known to be associated with this lesion in B-CLL.
Molecular and transcriptional characterization of 17p loss in B-cell chronic lymphocytic leukemia.
Sex
View SamplesMutation or epigenetic silencing of the transcription factor C/EBP is observed in ~10% of patients with acute myeloid leukemia (AML). In both cases, a common global gene expression profile is observed, but down-stream targets relevant for leukemogenesis are not known. Here we identify Sox4 as a direct target of C/EBP whereby its expression is inversely correlated with C/EBP activity. Downregulation of Sox4 abrogated increased self-renewal of leukemic cells and restored their differentiation. Gene expression profiles of leukemia initiating cells (LICs) from both Sox4 overexpression and murine mutant C/EBP AML models clustered together, but differed from other types of AML. Our data demonstrate that Sox4 overexpression resulting from C/EBP inactivation contributes to the development of leukemias with a distinct LIC phenotype.
Sox4 is a key oncogenic target in C/EBPα mutant acute myeloid leukemia.
Specimen part
View SamplesFollicular lymphoma (FL) is an indolent lymphoma associated with follicular center B cells, and typically contains the Bcl-2 chromosomal translocation t(14;18), which leads to overexpression of the anti-apoptotic intracellular protein Bcl-2. FLs are sensitive to chemotherapy; however, patient relapses occur and response duration becomes progressively shorter, with the majority of patients eventually dying from the disease. Enzastaurin (LY317615), an acyclic bisindolylmaleimide, was initially developed as an ATP-competitive selective inhibitor of PKC. We found, in agreement with recent reports, that enzastaurin inhibits cell proliferation and induces apoptosis. These results are consistent with decreased phosphorylation of the Akt pathway and its downstream targets. To provide new insights into the anti-tumor action of enzastaurin on non-Hodgkin lymphoma, we investigated its effects on gene expression profiles of the B cell lymphoma RL cell line by oligonucleotide microarray analysis. We identified a set of 41 differentially expressed genes, mainly involved in cellular adhesion, apoptosis, inflammation, and immune and defense responses. These observations provide new insights into the mechanisms involved in the induction of apoptosis by enzastaurin in B cell lymphoma cell lines, and identify possible pathways that may contribute to the induction of apoptosis.
Genomic profiling of enzastaurin-treated B cell lymphoma RL cells.
Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
In Silico Characterization of miRNA and Long Non-Coding RNA Interplay in Multiple Myeloma.
Specimen part, Disease
View Samples