Follicular lymphoma in situ and partial involvement by follicular lymphoma are clona lesions that carry the t(14;18) and lack genetic secondary alterations
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE48548 | GEO | 2013/11/12
SECONDARY ACCESSION(S): PRJNA210596
REPOSITORIES: GEO
Similar Datasets
Project description:Follicular lymphoma (FL) is characterized by the t(14;18)(q32;q21), frequent numerical chromosomal alterations, and recurrent somatic mutations. However, no genetic studies are available for FL in situ (FLIS), a putative precursor lesion of FL. In this study, we analyzed cases of FLIS without manifest (m)FL, partial involvement by FL (PFL), and paired cases of FLIS and mFL to detect possible early chromosomal imbalances, as well as DNA-methylation patterns of genomic regions of selected genes. We demonstrated that paired FLIS and mFL cases are always clonally related. FLIS and PFL have no or few secondary chromosomal imbalances detectable by copy number arrays and a lower level of gene methylation as compared to mFL. Additionally, EZH2 Tyr641 mutations were detected in a subset of both FLIS and PFL cases. In conclusion, this study provides evidence that FLIS represents a FL precursor lesion of long-lived clonal B-cells carrying the t(14;18) with no or few secondary genetic changes. The earliest secondary genetic alterations detected in FLIS are the EZH2 Tyr641 mutation and low levels of CNAs, as evidence of clonal evolution. Our data suggest that there may be more than one distinct lesion driving the progression from FLIS to manifest lymphoma. DNA from cases, 20 tumor samples (10 in situ Follicular lymphoma, 4 Partial infiltration folliculary lymphoma and 6 manifest FL) were analyzed with Agilent-014693 Human Genome CGH Microarray 244A platform for copy number alterations study. For cases 9-14 paired samples of in situ follicular lymphoma and manifest follicular lymphoma were analyzed. Agilent-014693 Human Genome CGH Microarray 244A arrays were performed according to the manufacturer's directions on DNA extracted from lymph nodes that were hybridized against a normal DNA (pool) of the same gender.
2013-11-12 | E-GEOD-48548 | biostudies-arrayexpress
Project description:Follicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied regarding their immunohistochemical, genetic, molecular and clinical features. Within a previously published series of 184 FL grade 1-3A with available gene expression data, we identified 17 FL lacking the t(14;18). Comparative genomic hybridization and high resolution SNP array profiling demonstrated that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles revealed an enrichment of germinal center B-cell associated signatures in t(14;18)-positive FL, whereas activated B-cell like, NFƒÛB, proliferation and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FL, in which 32% of t(14;18)-negative FL showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL.
2009-06-03 | GSE16131 | GEO
Project description:Follicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied regarding their immunohistochemical, genetic, molecular and clinical features. Within a previously published series of 184 FL grade 1-3A with available gene expression data, we identified 17 FL lacking the t(14;18). Comparative genomic hybridization and high resolution SNP array profiling demonstrated that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles revealed an enrichment of germinal center B-cell associated signatures in t(14;18)-positive FL, whereas activated B-cell like, NFƒÛB, proliferation and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FL, in which 32% of t(14;18)-negative FL showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL. Fresh-frozen tumor-biopsy specimens were obtained from 184 untreated patients who had received a diagnosis of follicular lymphoma. RNA was extracted from the biopsy specimens and was examined for gene expression with the use of Affymetrix U133A and U133B microarrays.
2009-06-02 | E-GEOD-16131 | biostudies-arrayexpress
Project description:Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been found in a significant number of patients with FL. Gene expression profiling (GEP) was performed to determine differential gene-expression between the EZH2 mutated vs unmutated subgroups in FL. Total RNA extracted from fresh frozen specimens with FL diagnosis were processed for hybridization to Affymetrix HG-U133 plus 2 arrays. To enhance the identification of differential gene expression in FL tumor cells only, FL cases with a high B-cell content (enriched B-cell signature of >2-fold above the mean of the B-cell signature (pan B-cell markers) in the entire FL data set) were chosen for analysis.
2014-07-01 | E-GEOD-55267 | biostudies-arrayexpress
Project description:We studied 277 lymphoma samples (198 FL and 79 transformed FL [tFL]) using a single-nucleotide polymorphism array to identify the secondary chromosomal abnormalities that drive the development of FL and its transformation to diffuse large B-cell lymphoma. This dataset is corresponding Gene expression data that is available for a subset of the tFL cases for Series GSE67385.
2016-05-07 | GSE81183 | GEO
Project description:Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been Follicular lymphoma (FL) is an indolent, but incurable subtype of non-Hodgkin lymphoma. These tumor harbor t (14;18) translocation in at least 90% of patients. Recently, activating EZH2 mutations have been found in a significant number of patients with FL. Gene expression profiling (GEP) was performed to determine differential gene-expression between the EZH2 mutated vs unmutated subgroups in FL.
2014-07-01 | GSE55267 | GEO
Project description:Background: 15% of high and 50% of low stage FL lack the t(14;18). Nevertheless, most of these cases express BCL2 by so far unknown mechanisms. Principals/Methodology: To find molecular mechanisms, triggering FL-pathogenesis in t(14;18)-negative FL, the exonic SNV-profiles of 33 FL with and 16 FL without t(14;18) were assessed by whole exome-sequencing and external SNV-data integration. The SNV-profile of the whole exome-sequenced FL was correlated with copy number, LOH and gene-expression data. Finally, the N-glycosylation status was assessed (LympTrack assay) in a separate validation cohort. Results: SNVs in FL with and without t(14;18) affected different genes, but accumulated in similar pathways, e.g. apoptosis, epigenetic processes and cell cycle/proliferation. Mutations in genes associated with immune-response were more prominently and those associated with NFkB and N-glycosylation selectively enriched in t(14;18)-negative FL. ~50% of mutated genes showed BCL2-asociation at high confidence in FL with and without t(14;18). Moreover, among the genes mutated in t(14;18)-negative FL 555 (~1/3) were affected by copy number alterations and/or copy-neutral LOH, 125 were differently expressed between FL with and without t(14;18) (p<0.01) and 62 were differentially expressed and affected by copy number alterations and/or copy-neutral LOH. N-glycosylation was strongly reduced in t(14;18)-negative FL as compared to results reported for historical FL cohorts. Conclusion: These results suggest a stronger crosstalk with the microenvironment that may compensate for the lack of N-glycosylation and a diverse portfolio of SNVs that may contribute to the upregulation of BCL2 and FL pathogenesis in t(14;18)-negative FL.
| EGAS00001002164 | EGA
Project description:Nodal marginal zone lymphoma is a poorly defined entity in the WHO classification, largely based on criteria by exclusion and the diagnosis often remains subjective. Follicular Lymphoma lacking t(14;18), have similar characteristics which results in a major potential diagnostic overlap which this study aims to dissect. Four subgroups of lymphoma samples (n=56) were analyzed with high-resolution arrayCGH; Nodal marginal zone lymphoma, t(14;18)-negative Follicular Lymphoma, localized t(14:18)-positive Follicular Lymphoma and disseminated t(14;18)-positive Follicular Lymphoma. Gains on chromosomes 7, 8 and 12 were observed in all subgroups. The mean number of aberrations was higher in disseminated t(14;18)-positive Follicular Lymphoma compared to localized t(14:18)-positive Follicular Lymphoma (p<0.01) and the majority of alterations in localized t(14:18)-positive Follicular Lymphoma were also found in disseminated t(14;18)-positive Follicular Lymphoma. Nodal marginal zone lymphoma was marked by 3q gains with amplifications of four genes. A different overall pattern of aberrations was seen in t(14;18)-negative Follicular Lymphoma compared to t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma is marked by specific (focal) gains on chromosome 3 as observed in Nodal marginal zone lymphoma. Our results support the notion that localized t(14:18)-positive Follicular Lymphoma represents an early phase of disseminated t(14;18)-positive Follicular Lymphoma. t(14;18)-negative Follicular Lymphoma bears aberrations that are more alike Nodal marginal zone lymphoma, suggesting a relation between these groups. Four subgroups of follicular lymphoma were analyzed: NMZL (n=14), t-FL (n=12), LOC t+FL (n=16), DIS t+FL (n=14).
2013-07-16 | E-GEOD-40641 | biostudies-arrayexpress
Project description:The hallmark of follicular lymphoma (FL) is the t(14;18) chromosomal translocation. However, constitutive expression of anti-apoptotic Bcl-2 alone is insufficient for lymphomagenesis and subsequent molecular hits are required. We explored the role of microRNA (miRNA or miR) in the biology of FL by generating miRNA profiles of enriched sorted grade 1 and 2 FL tumor cells derived from 18 patients compared with enriched germinal center B-cells derived from seven follicular hyperplasia (FH). Expression levels of 851 human miRs were assayed and 133 miRs were significantly differentially expressed in FL tumor cells. The expression of 44 miRs in three major groups generated a unique FL signature. MiRs in group 1 were increased in FL (miR-193-5p, -193b*, -345, -513b, -574-3p, -584, -663, -1287, -1295, and -1471). Group 2 was increased in the majority of FL cases but showed lower levels of expression in a subset of FL (let-7a, let-7f, miR-7-1*, -9, -9*, -20a, -20b, -30b, -96, -98, -194, -195, -221*, -374a, -451, -454, -502-3p, -532-3p, -574-3p, -664*, -1274a, -1274b, and -1260). MiR group 3 was decreased in FL (miR-17*, -30a, 33a, 106a*, -141, 202, -205, -222, 301b, -431*, and -570). Two patterns within FL were detected, largely due to the variable expression of group 2 miRs. The pattern with higher expression of group 2 miRs was associated with complete response to chemotherapy. Gene expression analysis of 199 genes related to lymphoma and tumor development performed in tandem indicated differential expression of 47 genes in FL including increased expression of AKT-1, PRKCE, IL4R, DROSHA, and MAPK1; and decreased expression of CHEK1, RAD51, CDKN1A, SOCS2, KLF4, BLIMP1 and IRF4. Functional studies provide evidence that miR-20a and -20b target CDKN1A/p21, miR-194 targets SOCS2, and miR-301b targets MAPK1 in FL, affecting cell proliferation and potentially contributing to lymphomagenesis. These findings suggest a role for aberrant miRNA expression in the biology of FL with prognostic and mechanistic implications. miRNA profiling was performed using Agilent miRNA array platform with RNAs isolated from sorted follicular lymphoma B cells and follicular hyperplasia B cells.
2012-05-02 | E-GEOD-28090 | biostudies-arrayexpress
Project description:The hallmark of follicular lymphoma (FL) is the t(14;18) chromosomal translocation. However, constitutive expression of anti-apoptotic Bcl-2 alone is insufficient for lymphomagenesis and subsequent molecular hits are required. We explored the role of microRNA (miRNA or miR) in the biology of FL by generating miRNA profiles of enriched sorted grade 1 and 2 FL tumor cells derived from 18 patients compared with enriched germinal center B-cells derived from seven follicular hyperplasia (FH). Expression levels of 851 human miRs were assayed and 133 miRs were significantly differentially expressed in FL tumor cells. The expression of 44 miRs in three major groups generated a unique FL signature. MiRs in group 1 were increased in FL (miR-193-5p, -193b*, -345, -513b, -574-3p, -584, -663, -1287, -1295, and -1471). Group 2 was increased in the majority of FL cases but showed lower levels of expression in a subset of FL (let-7a, let-7f, miR-7-1*, -9, -9*, -20a, -20b, -30b, -96, -98, -194, -195, -221*, -374a, -451, -454, -502-3p, -532-3p, -574-3p, -664*, -1274a, -1274b, and -1260). MiR group 3 was decreased in FL (miR-17*, -30a, 33a, 106a*, -141, 202, -205, -222, 301b, -431*, and -570). Two patterns within FL were detected, largely due to the variable expression of group 2 miRs. The pattern with higher expression of group 2 miRs was associated with complete response to chemotherapy. Gene expression analysis of 199 genes related to lymphoma and tumor development performed in tandem indicated differential expression of 47 genes in FL including increased expression of AKT-1, PRKCE, IL4R, DROSHA, and MAPK1; and decreased expression of CHEK1, RAD51, CDKN1A, SOCS2, KLF4, BLIMP1 and IRF4. Functional studies provide evidence that miR-20a and -20b target CDKN1A/p21, miR-194 targets SOCS2, and miR-301b targets MAPK1 in FL, affecting cell proliferation and potentially contributing to lymphomagenesis. These findings suggest a role for aberrant miRNA expression in the biology of FL with prognostic and mechanistic implications.
2012-05-03 | GSE28090 | GEO