Project description:It has been known that aberrant isoforms of Ikaros family ptoteins are expressed in malignant cells. We identified that PBMC of ATL (acute T-cell leukemia) patients expresses different patterns of Helios isoforms compared with normal PBMC. In order to investigate the biological impact of ATL-type Helios isoform, we conducted complehensive gene expression analyses in Jurkat cells overexpressing ATL-type Helios. Also, we investigated the influence of WT-Helios or WT-Ikaros knockdown on the gene expression profile and compared with that of the cells with ATL-type Helios overexpression.
Project description:It has been known that aberrant isoforms of Ikaros family ptoteins are expressed in malignant cells. We identified that PBMC of ATL (acute T-cell leukemia) patients expresses different patterns of Helios isoforms compared with normal PBMC. In order to investigate the biological impact of ATL-type Helios isoform, we conducted complehensive gene expression analyses in Jurkat cells overexpressing ATL-type Helios. Also, we investigated the influence of WT-Helios or WT-Ikaros knockdown on the gene expression profile and compared with that of the cells with ATL-type Helios overexpression. Total RNA samples from Jurkat cells were subjected to Cy-3 labeling followed by human whole genome gene expression microarray analyses.
Project description:In this study, the ectopic overexpressions of the wild-type Helios-1, non-canonical short isoforms Helios-Δ190-1186, Helios-Δ326-1431, and control in the Jurkat cells were utilized as the routine in vitro model of the T-cell acute lymphoblastic leukemia (T-ALL). We compared the microarray data for transcriptional analysis of the Jurkat cells with stable overexpression of full-length Helios-1, non-canonical short isoforms Helios-Δ190-1186, Helios-Δ326-1431, and mock transfected control.
Project description:Inositol 5-phosphatase SHIP is differentially expressed in Ikaros and Helios deficient cells. In the absense of Ikaros SHIP is upregulated where as in the absense of Helios it is downregulated. Ikaros binds to the promoter of the SHIP gene. Article provides insight into the mechanisms of action Ikaros employs to regulate BCR signaling. Two replicates of Ikaros deficient and wild type DT40 avian B cells.
Project description:Inositol 5-phosphatase SHIP is differentially expressed in Ikaros and Helios deficient cells. In the absense of Ikaros SHIP is upregulated where as in the absense of Helios it is downregulated. Ikaros binds to the promoter of the SHIP gene. Article provides insight into the mechanisms of action Ikaros employs to regulate BCR signaling.
Project description:To elucidate how IKAROS modulates CD19 surface expression in B cell acute lymphoblastic leukemic cells, we analyzed gene expression profile from isogenic IKAROS wild type (WT) or knock down (KD) B-ALL cell lines.
Project description:To elucidate how IKAROS modulates CD19 surface expression in B cell acute lymphoblastic leukemic cells, we analyzed chromatin landscape profile from isogenic IKAROS wild type (WT) or knock down (KD) B-ALL cell lines.
Project description:T cell development is accompanied by epigenetic changes that ensure the silencing of stem cell-related, and the activation of lymphocyte-specific programs. How transcription factors influence these changes remains unclear. We show that the Ikaros transcription factor interacts with the Polycomb Repressive Complex 2 (PRC2) in CD4-CD8- thymocytes, and allows its binding to >200 developmentally-regulated genes, many of which are expressed in hematopoietic stem cells. Loss of Ikaros in CD4-CD8- cells leads to diminished histone H3 Lys27 (H3K27) trimethylation and ectopic expression of these genes. Ikaros binding triggers PRC2 recruitment and H3K27 trimethylation. Furthermore, Ikaros interacts with PRC2 independently of the Nucleosome Remodeling and Deacetylation complex. Our results identify Ikaros as a fundamental regulator of PRC2 function in developing T cells. Genome-wide comparison of different histone modifications, Ikaros, Suz12 and NuRD binding in different stages of T cell development in WT and Ikaros mutant mice. Profiling of H3K27me3 in DN1, DN2, DN3, DN4 and DP thymocytes and hematopoietic stem and progenitor cells (LSK cells) of WT and Ikaros mutant mice. Profiling of H3K4me3 and H3ac in WT and Ikaros mutant DP thymocytes. Global analysis of Ikaros binding in WT DN3, DN4 and DP cells, Suz12 binding in WT and Ikaros mutant DN3 cells, and Mta2 and Mi2beta binding in WT DN3 cells. Genome-wide profiling of Ikaros binding and H3K27me3 upon Ikaros activation in Ikaros-deficient leukemic T cells.
Project description:Adult T-cell lymphoma/leukemia (ATL) is an aggressive subtype of leukemia/lymphoma caused by human T-cell leukemia virus type-1 (HTLV-1) and existing chemotherapy for ATL remains with extremely poor prognosis. Therefore, more effective therapeutic options are urgent needs for this disease. Since recent two clinical studies proved promising curability of Lenalidomide (LEN, a second-generation immunomodulatory drug [IMiDs]) for ATL patients, we investigated the direct growth-inhibitory machineries of LEN on ATL cells. Among 13 ATL-related cell lines, Hut102 and TL-Om1 exhibited best response to LEN treatment and LEN-induced functional modulation of E3-ubiquitin ligase cereblon (CRBN) induced degradation of hematopoietic-specific ikaros-family transcription factors IKZF1 and IKZF3 followed by suppression of their down-stream effectors IRF4 and c-Myc (both have been implied to promote ATL cell malignancy). Additionally, Hut102 and TL-Om1 displayed impaired expression of IKZF2 (deletion in HuT102 and altered translational variants in TL-Om1). LEN-induced growth inhibition to these two cell-lines seemed to be attributed to functional deprivation of all IKZF1/2/3. While CRBN-knockdown (KD) in HuT102 imposed LEN-resistance, IKZF2-KD in LEN-resistant ED40515 induced LEN sensitivity. DNA microarray analysis on LEN-treated HuT102 and OATL4 (LEN-resistant) displayed distinct LEN-responding transcriptional profiles; restoration of immune competency and oncogenic growth promotion respectively. Oral administration of LEN to HuT102-xenographted SCID mice demonstrated significant reduction of tumor mass. Finally, a novel form of IMiDs or cereblon modulator (CELMoD), iberdomide (IBE) exerted deeper and wider range of growth suppression to ATL cells including IKZF2 down regulation. Altogether, these findings strongly indicate the therapeutic advantages of IMiDs or CELMoD against ATL.
