Project description:Deregulated expression of cytokine receptor gene, CRLF2, is involved in lymphoid transformation in B-cell precursor acute lymphoblastic leukemia We report two novel, cryptic chromosomal abnormalities in precursor B-cell acute lymphoblastic leukemia (BCP-ALL): a translocation, either t(X;14)(p22;q32) or t(Y;14)(p11;q32), in 33 patients and an interstitial deletion, either del(X)(p22.33p22.33) or del(Y)(p11.32p11.32), in 64 patients, involving the pseudoautosomal region (PAR1) of the sex chromosomes. The incidence of these abnormalities was 5% in childhood ALL (0.8% with the translocation, 4.2% with the deletion). Patients with the translocation were older (median age 16 years), whilst the patients with the deletion were younger (median age 4 years). The two abnormalities result in deregulated expression of the cytokine receptor, cytokine receptor-like factor 2, CRLF2 (also known as thymic stromal-derived lymphopoietin receptor, TSLPR). Over-expression of CRLF2 was associated with activation of the JAK-STAT pathway in cell lines and transduced primary B-cell progenitors, sustaining their proliferation and indicating a causal role of CRLF2 over-expression in lymphoid transformation. In Down Syndrome (DS) ALL and two non DS BCP-ALL cell lines, CRLF2 deregulation was associated with mutations of the JAK2 pseudokinase domain suggesting oncogenic cooperation, as well as highlighting a link between non DS ALL and JAK2 mutations. Keyword(s): Global copy number analysis using Agilent oligonucleotide arrays DNA copy number analysis of 16 acute lymphoblastic leukaemia samples (13 diagnostic, 1 diagnostic and relapse pair and 2 cell-lines) was performed using Agilent 244K and 105K custom microarrays. These samples were hybridised against gender matched reference DNA.
Project description:Deregulated expression of the type I cytokine receptor, CRLF2 (CRLF2-d), is observed in 5-15% of B-cell precursor acute lymphoblastic leukaemia (BCP-ALL), is associated with activation of the JAK/STAT pathway and has an inferior outcome compared to those with good risk cytogenetics. We aimed to determine the clinical and genetic landscape of CRLF2-d ALL using genomic approaches including karyotyping, fluorescence in situ hybridisation, whole genome and whole exome sequencing. The clinical and demographic features of CRLF2-d patients were characteristic of BCP-ALL. Patients with IGH-CRLF2 were older than those with P2RY8-CRLF2 (4yrs v 14yrs, p<0.001), while the incidence of CRLF2-d among Down syndrome patients was high (31%). CRLF2-d co-occurred with established primary chromosomal rearrangements but the majority (72%) had B-other ALL. The copy number alteration (CNA) profile was similar to B-other ALL, although CRLF2-d patients harboured higher frequencies of IKZF1 (43% v 23%) and BTG1 deletions (15% v 2%). There were differences in the CNA profile between IGH-CRLF2 and P2RY8-CRLF2 patients: deletions of IKZF1 (71% v 33% p<0.001), BTG1 (31% v 9%, p=0.004) and ADD3 (46% v 13%, p=0.008). A novel gene fusion, USP9X-DDX3X was discovered in 18% of CRLF2-d ALL. Pathway analysis of the mutational profile revealed novel involvement of the focal adhesion pathway. In conclusion, CRLF2-d defines a discrete subtype of B-other ALL, characterised by a distinctive profile of cooperating abnormalities, which drive leukaemogenesis in conjunction with CRLF2-d. Although the functional relevance of many of these abnormalities are unknown, they likely activate alternative pathways, which may represent novel therapeutic targets. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or remission bone marrow.
Project description:Deregulated expression of cytokine receptor gene, CRLF2, is involved in lymphoid transformation in B-cell precursor acute lymphoblastic leukemia We report two novel, cryptic chromosomal abnormalities in precursor B-cell acute lymphoblastic leukemia (BCP-ALL): a translocation, either t(X;14)(p22;q32) or t(Y;14)(p11;q32), in 33 patients and an interstitial deletion, either del(X)(p22.33p22.33) or del(Y)(p11.32p11.32), in 64 patients, involving the pseudoautosomal region (PAR1) of the sex chromosomes. The incidence of these abnormalities was 5% in childhood ALL (0.8% with the translocation, 4.2% with the deletion). Patients with the translocation were older (median age 16 years), whilst the patients with the deletion were younger (median age 4 years). The two abnormalities result in deregulated expression of the cytokine receptor, cytokine receptor-like factor 2, CRLF2 (also known as thymic stromal-derived lymphopoietin receptor, TSLPR). Over-expression of CRLF2 was associated with activation of the JAK-STAT pathway in cell lines and transduced primary B-cell progenitors, sustaining their proliferation and indicating a causal role of CRLF2 over-expression in lymphoid transformation. In Down Syndrome (DS) ALL and two non DS BCP-ALL cell lines, CRLF2 deregulation was associated with mutations of the JAK2 pseudokinase domain suggesting oncogenic cooperation, as well as highlighting a link between non DS ALL and JAK2 mutations. Keyword(s): Global copy number analysis using Agilent oligonucleotide arrays
Project description:Genomic profiling efforts have revealed a rich diversity of oncogenic fusion genes, and many are emerging as important therapeutic targets. While there are many ways to identify fusion genes from RNA-seq data, visualising these transcripts and their supporting reads remains challenging. Clinker is a bioinformatics tool written in Python, R and Bpipe, that leverages the superTranscript method to visualise fusion genes. We demonstrate the use of Clinker to obtain interpretable visualizations of the RNA-seq data that lead to fusion calls. In addition, we use Clinker to explore multiple fusion transcripts with novel breakpoints within the P2RY8-CRLF2 fusion gene in B-cell Acute Lymphoblastic Leukaemia (B-ALL).
Project description:To determine the clinical and genetic landscape of CRLF2 deregulated acute lymphoblastic leukaemia (CRLF2-d ALL). We identified 172 patients with a CRLF2 rearrangement treated on either the UKALL2003 trial for children and adolescents (1-24 years) or the UKALLXII trial for adolescents and adults (15-59 years). Genomic technologies from conventional karyotyping, and FISH through to whole genome and exome sequencing were used to characterise the genomes of patients with CRLF2-d ALL. This is the largest study to date to investigate the genomic landscape of CRLF2-d ALL and define CRLF2-d as a unique subgroup of B-other ALL. We have confirmed the high incidence of CRLF2-d in Down syndrome-ALL and demonstrated the co-existence of CRLF2-d with other primary chromosomal rearrangements, suggesting that in these patients CRLF2-d can be a secondary genetic abnormality. Other defining features included enrichment of IKZF1, BTG1 and ADD3 deletions in IGH-CRLF2 patients and specific chromosomal gains seen at much higher frequencies than B-other ALL . We report recurrent established and new co-operating abnormalities and the novel involvement of USP9X and DDX3X in CRLF2-d ALL. It is clear from these data that CRLF2-d ALL is heterogenoeus, requiring a combination of genetic abnormalities in functionally relevent genes, to work alongside the deregulated expression of CRLF2 in order to initiate and drive leukaemogenesis in this subtype. Although the functional relevance of many of the abnormalities presented here are currently unknown, many are likely to activate alternate pathways or sensitize patients to current therapies.
Project description:To determine the clinical and genetic landscape of CRLF2 deregulated acute lymphoblastic leukaemia (CRLF2-d ALL). We identified 172 patients with a CRLF2 rearrangement treated on either the UKALL2003 trial for children and adolescents (1-24 years) or the UKALLXII trial for adolescents and adults (15-59 years). Genomic technologies from conventional karyotyping, and FISH through to whole genome and exome sequencing were used to characterise the genomes of patients with CRLF2-d ALL. This is the largest study to date to investigate the genomic landscape of CRLF2-d ALL and define CRLF2-d as a unique subgroup of B-other ALL. We have confirmed the high incidence of CRLF2-d in Down syndrome-ALL and demonstrated the co-existence of CRLF2-d with other primary chromosomal rearrangements, suggesting that in these patients CRLF2-d can be a secondary genetic abnormality. Other defining features included enrichment of IKZF1, BTG1 and ADD3 deletions in IGH-CRLF2 patients and specific chromosomal gains seen at much higher frequencies than B-other ALL . We report recurrent established and new co-operating abnormalities and the novel involvement of USP9X and DDX3X in CRLF2-d ALL. It is clear from these data that CRLF2-d ALL is heterogenoeus, requiring a combination of genetic abnormalities in functionally relevent genes, to work alongside the deregulated expression of CRLF2 in order to initiate and drive leukaemogenesis in this subtype. Although the functional relevance of many of the abnormalities presented here are currently unknown, many are likely to activate alternate pathways or sensitize patients to current therapies.