Project description:Expression of human miRNAs was analyzed in 150 ng of total RNA from nine post-transplant lymphoproliferative disorder (PTLD) patient samples, categorized as Epstein-Barr virus-positive (EBV+ , n = 4) or EBV- (n = 5) PTLD by hybridization on Affymetrix’s GeneChip miR Array 4.0 (Stanford Functional Genomics Facility, Stanford, CA). The Bioconductor ‘oligo’ package was used to perform array background subtraction, quantile normalization, and summarization by median polish. The normalized gene expression dataset was annotated with the ‘pd.mirna.4.0’ annotation library package in R (R Core Team). The expression data was fit to a linear model using the ‘stats’ package in R (R Core Team). Moderated t-statistics and log-odds of differential expression were calculated using the empirical Bayes method. False discovery rate (FDR) tests were performed with the Benjamini-Hochberg procedure for multiple testing correction in R (R Core Team).
Project description:In this study we focussed on malignant post-transplant lymphomas. Post-transplant lymphoma is strongly associated with Epstein-Barr Virus (EBV) infection in contrast to lymphoma arising in an immunocompetent population. Nevertheless, about 1 in 3 PTLD cases are negative for EBV. We used a microarray to define the gene expression profile of different PTLDs to elucidate the pathogenesis of EBV(+) and EBV(-) PTLD and to define whether EBV(-) PTLD is biologically different from EBV(-) lymphoma arising in an immunocompetent host. PTLD patient samples were randomly selected for RNA extraction and hybridization on an Affymetrix platform. The post-transplant tumors consisted of homogenous sheets of neoplastic cells ensuring reliability of the gene expression data.
Project description:Post-transplant lymphoproliferative disorders (PTLD) are a major complication of solid organ transplantation and represent a cause of severe morbidity and mortality among transplanted patients. Apart from EBV infection, knowledge of the pathogenesis of monoclonal PTLD is limited. Powerful analysis techniques, such as whole genomic DNA profiling (arrayCGH), can improve our understanding of PTLD pathogenesis. Toward this aim, we obtained the whole genome profiling using the Affymetrix GeneChip Human Mapping 10k 2.0 from 20 cases of PTLD and we compared them with those assessed in 25 cases of DLBCL from immunocompetent patients, as a control group. Recurrent lesions were detected among all the samples. Chromosome 18q, 7q, 3q and 12 were the most common gains in DLBCL of immunocompetent hosts. Chromosomes 5p and 11p were commonly gained in PTLD-DLBCL. The latter had frequent losses of 6q, 17p, 1p, and 9p. Chromosome 12p was the most frequent target of deletions among PTLD-DLBCL. The LOH pattern was characterized by involvement of chromosomes 13q and 17p in DLBCL and 10, 1q, 9p and 11q among PTLD-DLBCL. Interestingly, LOH did not always match the DNA loss. In particular, chromosome 10 seemes to be targeted by uniparental disomy in PTLD. Small deletions and gains, involving both known (BCL2 and PAX5) and unknown genes (ZDHHC14), have been identified. Our data suggest that PTLD share, at a lower frequency, common genetic aberrations with DLBCL from immunocompetent patients. The demonstration of 9p13 amplification indicates the importance of PAX5 in PTLD. The combination of DNA copy number and LOH assessment lead to the hypothesis that uniparental disomy may be a potential mechanism in B-cell lymphomagenesis. Twenty specimens of monoclonal B-cell PTLD, collected from 20 solid organ transplant recipients. Experiment Overall Design: 20 PTLD samples. No technical replications. Experiment Overall Design: 25 DLBCL samples (20 patient + 5 cell lines). No technical replications.
Project description:Post-transplant lymphoproliferative disorders (PTLD) are a major complication of solid organ transplantation and represent a cause of severe morbidity and mortality among transplanted patients. Apart from EBV infection, knowledge of the pathogenesis of monoclonal PTLD is limited. Powerful analysis techniques, such as whole genomic DNA profiling (arrayCGH), can improve our understanding of PTLD pathogenesis. Toward this aim, we obtained the whole genome profiling using the Affymetrix GeneChip Human Mapping 10k 2.0 from 20 cases of PTLD and we compared them with those assessed in 25 cases of DLBCL from immunocompetent patients, as a control group. Recurrent lesions were detected among all the samples. Chromosome 18q, 7q, 3q and 12 were the most common gains in DLBCL of immunocompetent hosts. Chromosomes 5p and 11p were commonly gained in PTLD-DLBCL. The latter had frequent losses of 6q, 17p, 1p, and 9p. Chromosome 12p was the most frequent target of deletions among PTLD-DLBCL. The LOH pattern was characterized by involvement of chromosomes 13q and 17p in DLBCL and 10, 1q, 9p and 11q among PTLD-DLBCL. Interestingly, LOH did not always match the DNA loss. In particular, chromosome 10 seemes to be targeted by uniparental disomy in PTLD. Small deletions and gains, involving both known (BCL2 and PAX5) and unknown genes (ZDHHC14), have been identified. Our data suggest that PTLD share, at a lower frequency, common genetic aberrations with DLBCL from immunocompetent patients. The demonstration of 9p13 amplification indicates the importance of PAX5 in PTLD. The combination of DNA copy number and LOH assessment lead to the hypothesis that uniparental disomy may be a potential mechanism in B-cell lymphomagenesis. Twenty specimens of monoclonal B-cell PTLD, collected from 20 solid organ transplant recipients. Keywords: Genomic DNA on Affymetrix 10K SNP array
Project description:The highly prevalent oncogenic Epstein-Barr virus (EBV) can drive tumorigenesis with disrupted host immunity, causing malignancies including post-transplant lymphoproliferative disorders (PTLD). PTLD can also arise in the absence of EBV but the biological differences underlying EBV(+) and EBV(-) B cell PTLD and the associated host-EBV-tumor interactions remain poorly understood. Here, we reveal the core differences between EBV(+) and EBV(-) PTLD, characterized by increased expression of genes related to immune processes or DNA interactions respectively, and the augmented ability of EBV(+) PTLD B cells to modulate the tumor microenvironment through elaboration of monocyte-attracting cytokines/chemokines. We create a reference resource of proteins distinguishing EBV(+) B lymphoma cells from EBV(-) B lymphoma including the immunomodulatory molecules CD300a and CD24, respectively. Moreover, we show that CD300a is essential for maximal survival of EBV(+) PTLD B lymphoma cells. Our comprehensive multi-modal analyses uncover the biological underpinnings of PTLD and offer opportunities for precision therapies.
Project description:The highly prevalent oncogenic Epstein-Barr virus (EBV) can drive tumorigenesis with disrupted host immunity, causing malignancies including post-transplant lymphoproliferative disorders (PTLD). PTLD can also arise in the absence of EBV but the biological differences underlying EBV(+) and EBV(-) B cell PTLD and the associated host-EBV-tumor interactions remain poorly understood. Here, we reveal the core differences between EBV(+) and EBV(-) PTLD, characterized by increased expression of genes related to immune processes or DNA interactions respectively, and the augmented ability of EBV(+) PTLD B cells to modulate the tumor microenvironment through elaboration of monocyte-attracting cytokines/chemokines. We create a reference resource of proteins distinguishing EBV(+) B lymphoma cells from EBV(-) B lymphoma including the immunomodulatory molecules CD300a and CD24, respectively. Moreover, we show that CD300a is essential for maximal survival of EBV(+) PTLD B lymphoma cells. Our comprehensive multi-modal analyses uncover the biological underpinnings of PTLD and offer opportunities for precision therapies.
Project description:The purpose of this study is to determine the clinical benefit and characterize the safety profile of tabelecleucel for the treatment of Epstein-Barr virus-associated post-transplant lymphoproliferative disease (EBV+ PTLD) in the setting of (1) solid organ transplant (SOT) after failure of rituximab and rituximab plus chemotherapy or (2) allogeneic hematopoietic cell transplant (HCT) after failure of rituximab.
Project description:In this study we focussed on malignant post-transplant lymphomas. Post-transplant lymphoma is strongly associated with Epstein-Barr Virus (EBV) infection in contrast to lymphoma arising in an immunocompetent population. Nevertheless, about 1 in 3 PTLD cases are negative for EBV. We used a microarray to define the gene expression profile of different PTLDs to elucidate the pathogenesis of EBV(+) and EBV(-) PTLD and to define whether EBV(-) PTLD is biologically different from EBV(-) lymphoma arising in an immunocompetent host.