Project description:We recently mapped 605 chromosomal breakpoints in 61 ATL cases by spectral karyotyping and identified chromosome 14q11 as one of the most common chromosomal breakpoint regions. To map the precise location of chromosomal breakpoints at 14q11, we performed single-nucleotide polymorphism (SNP)-based comparative genomic hybridization on leukemia cells from acute-type ATL patients. The breakpoints accumulated frequently adjacent to the T cell receptor alpha/delta chain locus (TCRα/δ) with chromosomal deletions at 14q11 and a recurrent 0.9 Mb interstitial deletion was identified at a region including part of the TCRα/δ locus. Because leukemia-associated genes are frequently located near the breakpoint cluster regions, we then analyzed the gene expression profiles of ATL cells and identified N-myc downstream regulated gene 2 (NDRG2) as one of the genes that are down-regulated in ATLL cells among the 25 genes mapped to the region adjacent to the recurrently deleted regions at 14q11. We compared the gene expression profiles of ATL cells from seven acute-type ATL patients and CD4+ T lymphocytes from the peripheral blood of five healthy volunteers as references using oligonucleotide microarrays.
Project description:To identify chromosomal alterations in ATL, SNP array analyses were performed in 19 leukemia cell samples from ATL patients and 9 ATL-related cell lines. ATL displayed complex chromosomal abnormalities, but it contained recurrent chromosomal amplification and deletion, including 14q11 and 14q32, which may be associated with the development of ATL. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved peripheral blood samples and from cell line samples.
Project description:Abstract: Adult T-cell leukemia/lymphoma (ATL) is an aggressive and fatal disease. We have examined 18 ATL patient samples using Affymetrix HG-U133A2.0 arrays. Using the BRB array program, we identified genes differentially expressed in leukemia cells compared to normal lymphocytes. Several unique genes were identified that were overexpressed in leukemia cells including TNFSF11, RGS13, MAFb, CSPG2, C/EBPalpha and TCF4. 200 of the most highly overexpressed ATL genes were analyzed by the PathwayStudio 4.0 program. ATL leukemia cells were characterized by an increase in genes linked to "central" genes CDC2/cyclin B1, SYK/LYN, PCNA and BIRC5. Because of its potential therapeutic importance, we focused our studies on the regulation and function of BIRC5, whose expression was increased in 13 of 14 leukemia samples. TCF4 reporter assays and transfection of DN-TCF4 demonstrated that TCF4 regulates BIRC5 gene expression. Functionally, transfection of ATL cells wi BIRC5 shRNA decreased BIRC5 exprression and cell viability 80%. Clinical treatment of ATL patients with Zenapax or bortezomib decreased BIRC5 expression and cell viability. These experiments represent the first direct experimental evidence that BIRC5 plays an important role in ATL cell viability and provides important insight into ATL genesis and potential targeted therapies. Keywords: disease state analysis
Project description:We examined the gene expression profiles of CD4+ T-cells isolated from 7 ATL, 12 HAM/TSP and 11 AC (asymptomatic carriers) to identify gene signatures that may be characteristic for these particular diseases. Using gene expression arrays, we identified ~ 1039 immune-related genes that were differentially expressed in CD4+ T cells; using stringent exclusion criteria, a 122 gene signature could be divided into 3 groups: I) ATL-specific; II) common; and III) HAM/TSP-specific markers
Project description:We examined the gene expression profiles of CD4+ T-cells isolated from 7 ATL, 12 HAM/TSP and 11 AC (asymptomatic carriers) to identify gene signatures that may be characteristic for these particular diseases. Using gene expression arrays, we identified ~ 1039 immune-related genes that were differentially expressed in CD4+ T cells; using stringent exclusion criteria, a 122 gene signature could be divided into 3 groups: I) ATL-specific; II) common; and III) HAM/TSP-specific markers To better understand the genetic differences between HTLV-1-associated diseases, we examined the gene expression profile of T lymphocytes from patients either suffering from ATL, HAM/TSP or carrying the HTLV-1 virus without any symptoms. Microarray experiments were performed using the human ImmuneArray cDNA array (UHN Microarray Center, University of Toronto). We used the Stratagene Universal Control, labelled Cy5 for all samples in a competitive hybridization.
Project description:HTLV-1 infected individuals stay as carriers for their lifetimes, while the rest of 5% are killed by ATL. ATL leukemogenesis is a complex process involving accumulation of multiple genetic abnormalities in HTLV-1 infected cells. To clarify genetic events underlying ATL leukemogenesis, we conducted comprehensive miRNA expression profiling in 40 ATL patients and in 22 healthy volunteers. Total RNA samples from PBMC of ATL patients (mostly HTLV-1 inefcted CD4+ T-cells) and from CD4+ T-cells from healthy donors were subjected to Cy-3 labeling followed by miRNA expression microarray analyses.
Project description:HTLV-1 infected individuals stay as carriers for their lifetimes, while the rest of 5% are killed by ATL. ATL leukemogenesis is a complex process involving accumulation of multiple genetic abnormalities in HTLV-1 infected cells. To clarify genetic events underlying ATL leukemogenesis, we conducted comprehensive gene expression profiling in 52 ATL patients and in 21 healthy volunteers. Total RNA samples from PBMC of ATL patients (mostly HTLV-1 inefcted CD4+ T-cells) and from CD4+ T-cells from healthy donors were subjected to Cy-3 labeling followed by human whole genome gene expression microarray analyses.
Project description:We recently mapped 605 chromosomal breakpoints in 61 ATL cases by spectral karyotyping and identified chromosome 14q11 as one of the most common chromosomal breakpoint regions. To map the precise location of chromosomal breakpoints at 14q11, we performed single-nucleotide polymorphism (SNP)-based comparative genomic hybridization on leukemia cells from acute-type ATL patients. The breakpoints accumulated frequently adjacent to the T cell receptor alpha/delta chain locus (TCRα/δ) with chromosomal deletions at 14q11 and a recurrent 0.9 Mb interstitial deletion was identified at a region including part of the TCRα/δ locus. Because leukemia-associated genes are frequently located near the breakpoint cluster regions, we then analyzed the gene expression profiles of ATL cells and identified N-myc downstream regulated gene 2 (NDRG2) as one of the genes that are down-regulated in ATLL cells among the 25 genes mapped to the region adjacent to the recurrently deleted regions at 14q11.
Project description:Adult T-cell Leukemia (ATL) is a highly chemoresistant malignancy of peripheral T lymphocytes, associated with retrovirus human T-cell leukemia virus type I (HTLV-1). To elucidate the complex molecular mechanism of anti-Growth effect of the HIV integrase inhibitor, MK-2048 in ATL cells, we attempted to perform gene expression profiling.