Project description:mRNA profiling of the Richter Syndrome cell line U-RT1. The expression profiles were compared to published expression profiles of different diffuse large B cell lymphoma cell lines (Array Express E MTAB-973 and GEO Accession Number GSM466597) to determine whether there are differences in expression that indicate differences on molecular grounds.
Project description:Richter syndrome (RS) occurs in up to 15% of patients with chronic lymphocytic leukemia (CLL). While RS, usually represented by the histologic transformation to a diffuse large B-cell lymphoma (DLBCL), is associated with a very poor outcome, especially when clonally related to the pre-existing CLL, mechanisms leading to RS have not been clarified yet. To better understand the pathogenesis of RS, we analyzed a series of cases including: 59 RS, 28 CLL-phase of RS, 315 CLL and 127 de novo DLBCL. RS demonstrated a genomic complexity intermediate between CLL and DLBCL. Cell cycle deregulation via inactivation of TP53 and of CDKN2A was a main mechanism in the histologic transformation from CLL-phase, being present in approximately half of the cases, and affected the outcome of the RS patients. A second major subgroup was characterized by the presence of trisomy 12 and comprised one third of the cases. While RS shared some of the lesions seen in de novo DLBCL, its genomic profile was clearly separate. The CLL-phase preceding RS had not a generalized increase in genomic complexity when compared with untransformed CLL, but it presented clear differences in the frequency of specific genetic lesions. Genomic profiling of Richter-syndrome Chronic Lymphocytic Leukemia
Project description:Richter syndrome (RS) occurs in up to 15% of patients with chronic lymphocytic leukemia (CLL). While RS, usually represented by the histologic transformation to a diffuse large B-cell lymphoma (DLBCL), is associated with a very poor outcome, especially when clonally related to the pre-existing CLL, mechanisms leading to RS have not been clarified yet. To better understand the pathogenesis of RS, we analyzed a series of cases including: 59 RS, 28 CLL-phase of RS, 315 CLL and 127 de novo DLBCL. RS demonstrated a genomic complexity intermediate between CLL and DLBCL. Cell cycle deregulation via inactivation of TP53 and of CDKN2A was a main mechanism in the histologic transformation from CLL-phase, being present in approximately half of the cases, and affected the outcome of the RS patients. A second major subgroup was characterized by the presence of trisomy 12 and comprised one third of the cases. While RS shared some of the lesions seen in de novo DLBCL, its genomic profile was clearly separate. The CLL-phase preceding RS had not a generalized increase in genomic complexity when compared with untransformed CLL, but it presented clear differences in the frequency of specific genetic lesions.
Project description:Richter syndrome (RS) is the aggressive transformation of Chronic Lymphocytic Leukemia, mostly with Diffuse Large B-Cell Lymphoma histology. While histologically similar, RS and de novo DLBCLs present with different clinical courses. We characterized the RS epigenome by combining genome-wide DNA methylation with transcriptome-sequencing on a large RS cohort.
Project description:Unlike many other hematologic malignancies, Richter syndrome (RS), an aggressive B cell lymphoma originating from indolent chronic lymphocytic leukemia, is responsive to PD-1 blockade. To discover the determinants of response, we analyzed single-cell transcriptome data generated from 17 bone marrow samples longitudinally collected from 6 RS patients. Response was associated with intermediate exhausted CD8 effector/effector memory T cells marked by high expression of the transcription factor ZNF683, determined to be evolving from stem-like memory cells and divergent from terminally exhausted cells. This signature overlapped with that of tumor-infiltrating populations from PD-1 responsive solid tumors. ZNF683 was found to directly target key T cell genes (TCF7, LMO2, CD69) and impact pathways of T cell cytotoxicity and activation. Analysis of pre-treatment peripheral blood from 10 independent RS PD-1 treated patients, as well as solid tumor PD-1 treated patients, supported an association of ZNF683high T cells with response.
Project description:Unlike many other hematologic malignancies, Richter syndrome (RS), an aggressive B cell lymphoma originating from indolent chronic lymphocytic leukemia, is responsive to PD-1 blockade. To discover the determinants of response, we analyzed single-cell transcriptome data generated from 17 bone marrow samples longitudinally collected from 6 RS patients. Response was associated with intermediate exhausted CD8 effector/effector memory T cells marked by high expression of the transcription factor ZNF683, determined to be evolving from stem-like memory cells and divergent from terminally exhausted cells. This signature overlapped with that of tumor-infiltrating populations from PD-1 responsive solid tumors. ZNF683 was found to directly target key T cell genes (TCF7, LMO2, CD69) and impact pathways of T cell cytotoxicity and activation. Analysis of pre-treatment peripheral blood from 10 independent RS PD-1 treated patients, as well as solid tumor PD-1 treated patients, supported an association of ZNF683high T cells with response.