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: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: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. Experiment Overall Design: Leukemic PBMC RNA from 30 patients was extracted for target preparation and hybridization onto Affymetrix microarrays. We also isolated PBMCs and PBMCs subjected to enrichment for CD8+ cells from control patients. RNA from these cells (naïve or activated with phytohemagglutinin) was extracted for target preparation and hybridization onto Affymetrix microarrays.
Project description:To identify Lgl binding proteins, we purified Lgl-containing protein complexes from cultured Drosophila S2 cells, using the single-step streptavidin purification from stable cell lines expressing SBP-tagged Lgl, followed by nanoLC-MS/MS analysis of the interactors. This study revealed the binding of Lgl to Vap33, which we further connected to the function of the vacuolar ATPase and regulation of Notch signaling.
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:Single channel custom oligonucleotide array of 147 microRNAs to detect changes in expression of a lgl-hypomorph mutant versus wild-type 0, 3, and 5 day old 3rd instar lgl-hypomorph larvae were compared to 0 day 3rd instar wild-type larvae to test for differences in microRNA expression
Project description:The nuclear lamina constitutes more than a structural scaffold for the nucleus and plays a crucial role in protection of genomic integrity. Here we report that the loss of the lysine acetyl-transferase (KAT) MOF leads to nuclear architecture defects during interphase including micronuclei formation. We identify Lamin A/C, a major component of the nuclear lamina, to be an acetylation target of MOF. A point mutation in Lamin A phenocopies nuclear morphology defects observed upon Mof-deletion. Through single cell DNA sequencing, we reveal that either loss of Mof or Lamin A mutation result in extensive genomic instability, including chromothripsis. Our work establishes MOF-dependent Lamin acetylation as a key regulator of nuclear architecture maintenance in mammals.
Project description:<p>LGL leukemia can be divided into three subsets including the following: αβ or γδT-LGL and NK-LGL leukemia. All three subtypes will be enrolled using a two-stage design. The primary endpoint of the study is assessment of overall clinical response. Correlative laboratory studies will be performed aimed at determining the mechanism of response to treatment. Thirteen participants will be accrued in the first stage at a dose of 300 mg BID administered intermittently every other week (i.e., 7 days on and 7 days off). If there are two or more responders, the protocol will be extended to a second stage of the study and accrual will be extended to 25 evaluable participants. Allowing for 10% rate of ineligibility due to unexpected events and dropout, we will accrue 14 patients in the first stage and 27 patients in total. Participants that withdraw from the study for reason unrelated to toxicity, will be replaced. There are two potential stopping rules for toxicity.</p> <p>If 3 or more participants out of the 13 enrolled in the first stage experiences grade IV neurotoxicity, the study will be stopped due to excessive toxicity. Dose reductions have been incorporated for hematologic toxicity. Treatment of T and NK LGL leukemia with immunosuppressive agents such as low-dose methotrexate generally require from four to six months for a clinical response and sometimes much longer. Therefore, in participants who show clinical improvement with less than grade three toxicity, tipifarnib treatment will be continued for as many as four additional months (12 months total). After the first 8 months, response will be assessed. The protocol treatment will be discontinued in participants with progression of disease. A long-term follow up will be performed for five years in patients that receive a complete clinical response. The long-term follow up will consist of vital signs, weight, CBCs, serum chemistries, and physical examination at six month intervals.</p>