Project description:We used microarrays to expression profile peripheral blood mononuclear cells (PBMCs) from LGL leukemia patients and control subjects to identify survival pathways that render leukemic LGL resistant to activation induced cell death. Keywords: granular lymphocyte leukemia, PBMC
Project description:Recent studies suggest the potential involvement of common antigenic stimuli on the ontogeny of monoclonal TCRalphabeta+/CD4+/NKa+/CD8-/+dim T-large granular lymphocyte (LGL) lymphocytosis. Since healthy individuals show (oligo)clonal expansions of hCMV-specific TCRVbeta+/CD4+/cytotoxic/memory T-cells, we investigate the potential involvement of hCMV in the origin and/or expansion of monoclonal CD4+ T-LGL. A detailed characterization of those genes that underwent changes in T-LGL cells responding to hCMV was performed by microarray gene expression profile (GEP) analysis.
Project description:TCRαβ CD8 large granular lymphocyte (LGL) leukemia is a rare heterogeneous hematological disorder with a chronic disease course that mostly affects elderly. It is generally accepted that LGL cells arise as a consequence of chronic antigenic stimulation and inflammation and thrive because of dysregulation of mainly the STAT3 but also to some extent the ERK pathway, which are constitutively activated. In approximately 40% of patients this is due to STAT3 activating mutations, but for the other 60% it remains to be elucidated, why the STAT3 pathway is chronically activated. miRNAs are one of the most potent regulators in health and disease and are also linked with various leukemias. Therefore, we hypothesized that aberrant miRNA expression could contribute to dysregulation of the STAT3 pathway. miRNA sequencing in LGL leukemia cases and aged-matched healthy control TEMRA cells revealed overexpression of miRNA181a. Furthermore, gene set enrichment analysis (GSEA) of miRNA181a implicated its involvement in the STAT3 and ERK1/2 pathways. Phosphoflow analysis of STAT3, ERK1/2 in miR181a-transfected human CD8 T cells revealed that miR181a overexpression results in STAT3 and ERK1/2 phosphorylation. By using TL1, a human T-LGL cell line model, we have now established that miR181a is the common actor in T-LGL leukemia, driving STAT3 activation by SOCS3 inhibition in LGL leukemia patients. Additionally, miR181a induces ERK1/2 phosphorylation by inhibition of DUSP6. Taken together, our data show that miR181a is the missing link to explain why STAT3-unmutated patients show hyperactive STAT3.
Project description:TCRαβ CD8 large granular lymphocyte (LGL) leukemia is a rare heterogeneous hematological disorder with a chronic disease course that mostly affects elderly. It is generally accepted that LGL cells arise as a consequence of chronic antigenic stimulation and inflammation and thrive because of dysregulation of mainly the STAT3 but also to some extent the ERK pathway, which are constitutively activated. In approximately 40% of patients this is due to STAT3 activating mutations, but for the other 60% it remains to be elucidated, why the STAT3 pathway is chronically activated. miRNAs are one of the most potent regulators in health and disease and are also linked with various leukemias. Therefore, we hypothesized that aberrant miRNA expression could contribute to dysregulation of the STAT3 pathway. miRNA sequencing in LGL leukemia cases and aged-matched healthy control TEMRA cells revealed overexpression of miRNA181a. Furthermore, gene set enrichment analysis (GSEA) of miRNA181a implicated its involvement in the STAT3 and ERK1/2 pathways. Phosphoflow analysis of STAT3, ERK1/2 in miR181a-transfected human CD8 T cells revealed that miR181a overexpression results in STAT3 and ERK1/2 phosphorylation. By using TL1, a human T-LGL cell line model, we have now established that miR181a is the common actor in T-LGL leukemia, driving STAT3 activation by SOCS3 inhibition in LGL leukemia patients. Additionally, miR181a induces ERK1/2 phosphorylation by inhibition of DUSP6. Taken together, our data show that miR181a is the missing link to explain why STAT3-unmutated patients show hyperactive STAT3.
Project description:Our results suggest that STAT3 can be activated independent of key oncogenic driver mutations in its SH2 domain in a subset of patients with large granular lymphocyte disorders. We examined the gene expression pattern in T-LGL leukemias compared to controls, and the impact of the presence of STAT3 mutations on the transcriptional regulation of a specific set of genes previously described.
2012-08-03 | GSE39838 | GEO
Project description:T-cell large granular lymphocyte leukemia