Project description:The cutaneous T-cell lymphoma Hut78 was treated with ribavirin for 120 h, and the gene expression of the treated cells was compared with respect to the expression of the cells without treatment. We evaluated the effect of treatment with ribavirin upon gene expression in a cutaneous T-cell lymphoma model, Hut78. Ribavirin treatment decreased approximately 90% of the viability of Hut78 cells. A complete genomic analysis of transcriptomic status after treatment with ribavirin of cutaneous T cell lymphoma Hut78 revealed an impact on the overall expression of transcripts.
Project description:The aim was to dissect molecular changes in histone and non-histone protein acetylation dynamics following the genetic or pharmacological inhibition of HDAC activity in a model of Anaplastic Large Cell Lymphoma (ALCL), a T cell non-Hodgkin lymphoma, predominantly found in children and adolescents.
Project description:Similar to resting mature B cells, where the B-cell antigen receptor (BCR) is essential for cellular survival, surface BCR expression is conserved in most mature B cell lymphomas. The identification of activating BCR mutations and the growth disadvantage upon BCR knockdown of cells of certain lymphoma entities has led to the view that BCR signaling is required for tumour cell survival. Consequently, the BCR signaling machinery has become a new target in the therapy of B cell malignancies. Here, we studied the effects of BCR ablation on MYC-driven mouse B cell lymphomas and compared them to observations in human Burkitt lymphoma. Whereas BCR ablation did not, per se, significantly affect lymphoma growth, BCR-negative (BCR-) tumour cells rapidly disappeared in the presence of their BCR-expressing (BCR+) counterparts in vitro and in vivo. This required neither cellular contact, nor factors released by BCR+ tumour cells. Instead, BCR loss induced the rewiring of central carbon metabolism increasing the sensitivity of receptor-less lymphoma cells to nutrient restriction. The BCR attenuated GSK3β activity to support MYC-controlled gene expression. BCR- tumour cells exhibited increased GSK3β activity and were rescued from their competitive growth disadvantage by GSK3β. BCR-negative lymphoma variants that restored competitive fitness, normalized GSK3β following constitutive activation of the MAPK pathway, commonly through Ras mutations. Similarly, in Burkitt lymphoma, activating RAS mutations may propagate Ig-crippled tumour cells, which usually represent a minority of the tumour bulk. Thus, while BCR expression enhances lymphoma cell fitness, BCR-targeted therapies may profit from combinations with drugs targeting BCR-less tumour cells. In this dataset, we included the expression data obtained from BCR-positive (BCR+) and BCR-negative (BCR-) lymphoma cells co-cultured for 4 days in presence or absence of GSK3b inhibitor, CHIR99021. These data were used to obtain genes that are regulated by the BCR through GSK3b inhibition.
Project description:Several studies have indicated an important role for miR-155 in the pathogenesis of B-cell lymphoma. Highly elevated levels of miR-155 were indeed observed in most B-cell lymphomas with the exception of Burkitt lymphoma (BL). However, the molecular mechanisms that underlie the oncogenic role of miR-155 in B-cell lymphoma are not well understood. To identify the miR-155 targets relevant for B-cell lymphoma, we performed RNA immunoprecipitation of Argonaute 2 in Hodgkin lymphoma (HL) cells upon miR-155 inhibition and in BL cells upon ectopic expression of miR-155. We identified 54 miR-155-specific target genes in BL cells and confirmed miR-155 targeting of DET1, NIAM, TRIM32, HOMEZ, PSIP1 and JARID2. Five of these targets are also regulated by endogenous miR-155 in HL cells. Both overexpression of miR-155 and inhibition of expression of the novel miR-155 target gene NIAM increased proliferation of BL cells. In primary B-cell lymphoma NIAM-positive cases have significant lower levels of miR-155 as compared to NIAM-negative cases, suggesting that NIAM is also regulated by miR-155 in primary B-cell lymphoma. Thus, our data indicate an oncogenic role for miR-155 in B-cell lymphoma which involves targeting the tumor suppressor NIAM.
Project description:Several studies have indicated an important role for miR-155 in the pathogenesis of B-cell lymphoma. Highly elevated levels of miR-155 were indeed observed in most B-cell lymphomas with the exception of Burkitt lymphoma (BL). However, the molecular mechanisms that underlie the oncogenic role of miR-155 in B-cell lymphoma are not well understood. To identify the miR-155 targets relevant for B-cell lymphoma, we performed RNA immunoprecipitation of Argonaute 2 in Hodgkin lymphoma (HL) cells upon miR-155 inhibition and in BL cells upon ectopic expression of miR-155. We identified 54 miR-155-specific target genes in BL cells and confirmed miR-155 targeting of DET1, NIAM, TRIM32, HOMEZ, PSIP1 and JARID2. Five of these targets are also regulated by endogenous miR-155 in HL cells. Both overexpression of miR-155 and inhibition of expression of the novel miR-155 target gene NIAM increased proliferation of BL cells. In primary B-cell lymphoma NIAM-positive cases have significant lower levels of miR-155 as compared to NIAM-negative cases, suggesting that NIAM is also regulated by miR-155 in primary B-cell lymphoma. Thus, our data indicate an oncogenic role for miR-155 in B-cell lymphoma which involves targeting the tumor suppressor NIAM.
Project description:Similar to resting mature B cells, where the B-cell antigen receptor (BCR) is essential for cellular survival, surface BCR expression is conserved in most mature B cell lymphomas. The identification of activating BCR mutations and the growth disadvantage upon BCR knockdown of cells of certain lymphoma entities has led to the view that BCR signaling is required for tumour cell survival. Consequently, the BCR signaling machinery has become a new target in the therapy of B cell malignancies. Here, we studied the effects of BCR ablation on MYC-driven mouse B cell lymphomas and compared them to observations in human Burkitt lymphoma. Whereas BCR ablation did not, per se, significantly affect lymphoma growth, BCR-negative (BCR-) tumour cells rapidly disappeared in the presence of their BCR-expressing (BCR+) counterparts in vitro and in vivo. This required neither cellular contact, nor factors released by BCR+ tumour cells. Instead, BCR loss induced the rewiring of central carbon metabolism increasing the sensitivity of receptor-less lymphoma cells to nutrient restriction. The BCR attenuated GSK3β activity to support MYC-controlled gene expression. BCR- tumour cells exhibited increased GSK3β activity and were rescued from their competitive growth disadvantage by GSK3β. BCR-negative lymphoma variants that restored competitive fitness, normalized GSK3β following constitutive activation of the MAPK pathway, commonly through Ras mutations. Similarly, in Burkitt lymphoma, activating RAS mutations may propagate Ig-crippled tumour cells, which usually represent a minority of the tumour bulk. Thus, while BCR expression enhances lymphoma cell fitness, BCR-targeted therapies may profit from combinations with drugs targeting BCR-less tumour cells. In this dataset, we included the expression data obtained from BCR-positive (BCR+), BCR-negative (BCR-) and BCR-independent lymphoma cells co-cultured for four days in presence or absence of GSK3b inhibitor, CHIR99021. This data was used to a) identify genes regulated by the BCR through GSK3b inhibition, and b) identify genes that confers BCR-independency to lymphoma variants resistant to BCR loss.
Project description:Several studies have indicated an important role for miR-155 in the pathogenesis of B-cell lymphoma. Highly elevated levels of miR-155 were indeed observed in most B-cell lymphomas with the exception of Burkitt lymphoma (BL). However, the molecular mechanisms that underlie the oncogenic role of miR-155 in B-cell lymphoma are not well understood. To identify the miR-155 targets relevant for B-cell lymphoma, we performed RNA immunoprecipitation of Argonaute 2 in Hodgkin lymphoma (HL) cells upon miR-155 inhibition and in BL cells upon ectopic expression of miR-155. We identified 54 miR-155-specific target genes in BL cells and confirmed miR-155 targeting of DET1, NIAM, TRIM32, HOMEZ, PSIP1 and JARID2. Five of these targets are also regulated by endogenous miR-155 in HL cells. Both overexpression of miR-155 and inhibition of expression of the novel miR-155 target gene NIAM increased proliferation of BL cells. In primary B-cell lymphoma NIAM-positive cases have significant lower levels of miR-155 as compared to NIAM-negative cases, suggesting that NIAM is also regulated by miR-155 in primary B-cell lymphoma. Thus, our data indicate an oncogenic role for miR-155 in B-cell lymphoma which involves targeting the tumor suppressor NIAM.
Project description:MYC regulates the expression of multiple microRNA (miRNA) genes and defines the Burkitt lymphoma (BL) miRNA signature. Here, we investigate the role of the MYC-regulated miRNAs by gain- and loss-of-function analysis. Overexpression of 5 miRNAs that were significantly downregulated by MYC resulted in strong (miR-150, miR-26a, miR-26b) and mild (miR-29a, let-7a) impaired cell growth. Overexpression of miR-155 increased proliferation of BL cells. By RNA immunoprecipitation of Argonaute 2 in BL cells with and without miR-155 we identified 54 miR-155 target genes. Using an shRNA approach we identified TBRG1 (NIAM1) as a miR-155 target gene that copied the miR-155-induced phenotype upon its inhibition. Analysis of TBRG1 protein expression and miR-155 levels in primary cases of B-cell lymphoma revealed that miR-155 levels are significantly lower in TBRG1 positive cases suggesting that TBRG1 is also regulated by miR-155 in primary B-cell lymphoma. Our data demonstrate that overexpression of individual MYC-repressed miRNAs has a strong suppressive effect on BL cell growth, whereas overexpression of miR-155 enhances B-cell lymphoma growth by targeting the tumor suppressor gene TBRG1. Gene expression profile was performed in ST486 Burkitt lymphoma cell line in 4 samples: ST486 EV (empty MXW-PGK-IRES-GFP vector) total cell lysate, ST486 EV Ago2-IP, ST486 miR-155 (ST486 with ectopic miR-155) total cell lysate, ST486 miR-155 Ago2-IP.
Project description:This phase I trial studies the side effects and the best dose of alisertib when given together with vorinostat in treating patients with Hodgkin lymphoma, B-cell non-Hodgkin lymphoma, or peripheral T-cell lymphoma that has come back. Alisertib and vorinostat may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth.