Project description:We report changes in the DNA methylome in a patient with γδ hepatosplenic T-cell lymphoma (HSTCL) who responded to treatment with interferon-α2c. We studied the methylome by 450k methylation array in 5 blood samples taken within a time period of 20 months. During this time period, the WBC counts dropped from 22,300 to 7,200/μl blood, yet the proportion of γδ T cell lymphoma blasts remained around 90%. We observed time-dependent changes in overall DNA methylation and performed an in-depth bioinformatic analysis of the modulated CpG sites associated with disease progression. We identified a CpG site differentially regulating methylation, possibly related to the interferon response during the course of treatment in this particular case. Therefore, the present case report will help to understand the substantial changes in DNA methylation of lymphoma resulting in a survival benefit of this γδ HSTCL patient.
Project description:Hepatosplenic ?? T-cell lymphoma (HSTCL) is a very rare peripheral T-cell lymphoma characterized by extranodal infiltration of mature malignant post-thymic T-lymphocytes into sinusoids of the liver and spleen without lymphadenopathy and significant cytopenias. The aetiology of the disease is unknown. We describe the case of a female patient in whom HSTCL developed after delivery and who was previously without disease. Flow cytometry and liver puncture are essential for diagnosing HSTCL, especially in patients with unexplained pancytopenia and hepatosplenomegaly. Since phenotypic results can easily be misinterpreted as non-malignant, the examiner should have enough experience to recognize clonal changes of T-lymphocytes. Namely, in contrast to B-lymphocytes, T-lymphocytes do not have an efficient indicator of clonality and are recognized by flow cytometry based only on aberrant expression of commonly present antigens of T-cell and NK-cell subsets. At present, there is no known cure for HSTCL with a maximum survival up to 2 years.
Project description:A 24-year-old male presented with abdominal pain, fever, and palpable splenomegaly. His differential count revealed myelocytes, metamyelocytes, and nucleated red cells. A bone marrow biopsy confirmed a diagnosis of hepatosplenic gamma delta T-cell leukemia/lymphoma. We describe here our center's diagnostic and treatment approach for this rare leukemia.
Project description:Hepatosplenic T-cell lymphoma (HSTL) is an aggressive lymphoma cytogenetically characterized by isochromosome 7q [i(7)(q10)], of which the molecular consequences remain unknown. We report here results of an integrative genomic and transcriptomic (expression microarray and RNA-sequencing) study of six HSTL cases with i(7)(q10) and three cases with ring 7 [r(7)], a rare variant aberration. Using high resolution array CGH, we prove that HSTL is characterized by the common loss of a 34.88 Mb region at 7p22.1p14.1 (3506316-38406226 bp) and duplication/amplification of a 38.77 Mb region at 7q22.11q31.1 (86259620-124892276 bp). Our data indicate that i(7)(q10)/r(7)-associated loss of 7p22.1p14.1 is a critical event in the development of HSTL, while gain of 7q sequences drives progression of the disease and underlies its intrinsic chemoresistance. Loss of 7p22.1p14.1 does not target a postulated tumor suppressor gene but unexpectedly enhances the expression of CHN2 from the remaining 7p allele, resulting in overexpression of β2-chimerin and dysregulation of a pathway involving RAC1 and NFATC2 with a cell proliferation response. Gain of 7q leads to increased expression of critical genes, including RUNDC3B, PPP1R9A and ABCB1, a known multidrug resistance gene. RNA-sequencing did not identify any additional recurrent mutations or gene fusions, suggesting that i(7)(q10) is the only driver event in this tumor. Our study confirms the previously described gene expression profile of HSTL and identifies a set of 24 genes, including three located on chromosome 7 (CHN2, ABCB1 and PPP1R9A), distinguishing HSTL from other malignancies
Project description:Hepatosplenic T-cell lymphoma (HSTL) is an aggressive lymphoma cytogenetically characterized by isochromosome 7q [i(7)(q10)], of which the molecular consequences remain unknown. We report here results of an integrative genomic and transcriptomic (expression microarray and RNA-sequencing) study of six HSTL cases with i(7)(q10) and three cases with ring 7 [r(7)], a rare variant aberration. Using high resolution array CGH, we prove that HSTL is characterized by the common loss of a 34.88 Mb region at 7p22.1p14.1 (3506316-38406226 bp) and duplication/amplification of a 38.77 Mb region at 7q22.11q31.1 (86259620-124892276 bp). Our data indicate that i(7)(q10)/r(7)-associated loss of 7p22.1p14.1 is a critical event in the development of HSTL, while gain of 7q sequences drives progression of the disease and underlies its intrinsic chemoresistance. Loss of 7p22.1p14.1 does not target a postulated tumor suppressor gene but unexpectedly enhances the expression of CHN2 from the remaining 7p allele, resulting in overexpression of β2-chimerin and dysregulation of a pathway involving RAC1 and NFATC2 with a cell proliferation response. Gain of 7q leads to increased expression of critical genes, including RUNDC3B, PPP1R9A and ABCB1, a known multidrug resistance gene. RNA-sequencing did not identify any additional recurrent mutations or gene fusions, suggesting that i(7)(q10) is the only driver event in this tumor. Our study confirms the previously described gene expression profile of HSTL and identifies a set of 24 genes, including three located on chromosome 7 (CHN2, ABCB1 and PPP1R9A), distinguishing HSTL from other malignancies Total genomic DNA was isolated from fresh frozen lymphoma samples using standard procedures. Genomic profiling, following the manufacturer’s protocols, was performed using the Affymetrix CytoScan HD arrays (www.affymetrix.com)
Project description:Interferon (IFN) gamma's ability to localise in the nucleus and function in gene activation has been known for some time, although the role of the conventional nuclear transporting importin molecules is unclear. Here, we demonstrate for the first time the direct recognition of IFNgamma and an IFNgamma mimetic peptide by IMPalpha and the IMPalpha/beta heterodimer, where the IFNgamma mimetic shows higher affinity. Significantly, this correlates well both with in vivo ability to target green fluorescent protein to the nucleus in transfected cells as determined by quantitative confocal laser scanning microscopy, as well as GAS promoter activity of a luciferase reporter. This has important implications for IFNgamma's anti-viral action, and the potential use of the IFNgamma mimetic in antiviral therapies.
Project description:Primary cutaneous gamma-delta T-cell lymphoma (PCGD-TCL) is a very rare lymphoma with an aggressive clinical course and a dismal outcome. The prognosis is linked to a pronounced resistance to chemotherapy and radiotherapy. No standard treatment approach is defined due to the low frequency of the disease and lack of prospective studies. CD30 is expressed in almost half of the cases of PCGD-TCL, which offers a potential therapeutic option. We report the successful treatment of a 68-year-old man who suffered PCGD-TCL with a combination of Brentuximab Vedotin and Gemcitabine after the failure of two lines of previous chemotherapy. CD30 expression was only partial. The treatment was very well tolerated and allowed the patient to benefit from allogeneic hematopoietic stem cell transplantation.