Project description:Epigenetic alterations are common in both B cell and T cell lymphomas. These contribute to lymphomagenesis and treatment resistance, hence epigenetic therapy is being investigated. We evaluated the effects of the DNA-methyltrasferase inhibitor hydralazine and the histone deacetylase inhibitor valproate in T-cell lymphoma HuT78 cells and B-cell lymphoma Raji cells.
Project description:Adoptive T-cell therapy or oncolytic virotherapy has made significant progress, but the efficacy was limited by the lack of infiltration into solid tumors when used alone. Here, an oncolytic virus (rVSV-LCMVG) was designed and combined with adoptively transferred T cells. By turning cold tumors hot, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy, whether rVSV-LCMVG was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and sensitized refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD1, and restoring effector-T cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells, and exhibited comparable amplified anti-tumor effects. This study proposed a rational combination therapy of oncolytic virus with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.
Project description:Adoptive T-cell therapy or oncolytic virotherapy has made significant progress, but the efficacy was limited by the lack of infiltration into solid tumors when used alone. Here, an oncolytic virus (rVSV-LCMVG) was designed and combined with adoptively transferred T cells. By turning cold tumors hot, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy, whether rVSV-LCMVG was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and sensitized refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD1, and restoring effector-T cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells, and exhibited comparable amplified anti-tumor effects. This study proposed a rational combination therapy of oncolytic virus with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.
Project description:Purpose: Despite recent advances in the treatment of patients with aggressive lymphomas, still a significant fraction of patients will succumb to their disease. Thus, novel therapeutic strategies are urgently needed. As the anti-CD20 antibody rituximab and the CD19-targeting antibody tafasitamab share distinct modes of actions, we investigated if dual-targeting of aggressive lymphoma B-cells by combining rituximab and tafasitamab might increase cytotoxic effects. Experimental Design: Antibody single and combination efficacy was determined investigating different modes of action including direct cytotoxicity, antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) in vitro and in vivo models of aggressive B-cell lymphoma comprising diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL). Results: Overall, three different sensitivity profiles to antibody monotherapy or combination treatment were observed in in vitro models: while 2/11 cell lines were primarily sensitive to tafasitamab and 2/11 were predominantly sensitive to rituximab treatment, the combination of tafasitamab and rituximab resulted in enhanced cell death in 7/11 cell lines in at least one mode of action. Treatment with either antibody or the combination resulted in decreased expression of the oncogenic transcription factor MYC and inhibition of AKT signaling which mirrored the cell line-specific sensitivities to direct cytotoxicity. At last, the combinatorial approach of the two antibodies resulted in a synergistic survival benefit in a PBMC-humanized Ramos NOD/SCID mouse model. Conclusions: This study demonstrates that the combination of tafasitamab and rituximab improves efficacy compared to antibody mono treatment in models of aggressive B-cell lymphoma in vitro and in vivo. Translational Relevance: The immunochemotherapy of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) remains the standard of care for newly diagnosed DLBCL patients. However, 30-40% of patients are refractory or relapse after initial response to the immunochemotherapy, indicating a high-unmet medical need for these patients. Tafasitamab and rituximab target the B-cell surface proteins CD19 and CD20, respectively, and both antibodies feature overlapping modes of action , namely direct cytotoxicity, ADCC and ADCP. In this study, we show that the combination of tafasitamab and rituximab had additive and synergistic efficacy both in vitro and in vivo. Our findings shed new light on the underlying mechanism of the combination of both antibodies and lay the ground to translate the results into improved outcome for patients with aggressive lymphoma in future clinical trials.
Project description:This study provides an evaluation of changes in gene expression associated with sodium valproate treatment of rat hepatocytes in vitro. Primary rat hepatocytes were treated for 24 and 48 hours with two doses (500 uM and 10 mM) of sodium valproate and water vehicle control. Five replicates of each treatment were performed. Cells were then extracted and RNA processed for microarray analysis.
Project description:CD137 (4-1BB) is a member of the TNFR family that mediates potent T-cell costimulatory signals upon ligation by CD137L or agonist monoclonal antibodies. CD137 agonists attain immunotherapeutic antitumor effects in cancer mouse models and multiple agents of this kind are undergoing clinical trials. We show that cIAP1 and cIAP2 are physically associated with the CD137-signaling complex. Moreover, cIAPs are required for CD137 signaling towards the NF-κB and MAPK pathways and for costimulation of human and mouse T lymphocytes. Functional evidence was substantiated with SMAC-mimetics that trigger cIAPs degradation and by transfecting cIAP dominant-negative variants. Antitumor effects of agonist anti-CD137 mAbs are critically dependent on the integrity of cIAPs in cancer mouse models and cIAPs are also required for signaling from CARs encompassing CD137’s cytoplasmic tail.
Project description:Molecular targeted therapy has shown promise as a treatment for advanced hepatocellular carcinoma (HCC). Sorafenib, a multikinase inhibitor, recently received FDA approval for the treatment of advanced HCC. However, although sorafenib is well tolerated, concern for its safety has been expressed. Celecoxib (CelebrexM-BM-.) is a selective cyclooxygenase-2 (COX-2) inhibitor wich exhibits antitumor effects in human HCC cells. The present study examined the interaction between celecoxib and sorafenib in two human liver tumor cell lines HepG2 and Huh7. Our data showed that each inhibitor reduced cell growth and the combination of celecoxib with sorafenib synergistically inhibited cell growth and increased apoptosis. To better understand the molecular mechanisms underlying the synergistic antitumor activity of combination, we investigated the expression profile of the combination-treated liver cancer cell lines, using microarray analysis. Combination treatment significantly altered expression levels of 1,986 and 2,483 transcripts in HepG2 and Huh7 cells, respectively. Genes, functionally involved in cell death, signal transduction and regulation of transcription were predominantly up-regulated, while genes implicated in metabolism, cell cycle control and DNA replication and repair were mainly down-regulated upon treatment. However, combination-treated HCC cell line displayed specificity in the expression and activity of crucial factors involved in hepatocarcinogenesis. The altered expression of some of these genes was confirmed by semiquantitative and quantitative RT-PCR and by Western blotting. Many novel genes emerged from our transcriptomics analyses, and further functional analyses may determine whether these genes can serve as potential molecular targets for more effective anti-HCC strategies. To identify new potential mechanisms of combined action of celecoxib and sorafenib, their effects on global gene expression in both cell lines were investigated and compared using the DNA microarray technology. Agilent 44K Human Whole Genome Oligonucleotide Microarrays (containing ~44,000 genes) were used to identify global gene expression changes in the HepG2 and Huh7 hepatocellular carcinoma (HCC) cell lines, following simultaneous treatment with 50 M-BM-5M celecoxib and 7.5 M-BM-5M sorafenib for 48 hours. All microarray experiments (a total of four) were performed in duplicates applying dye-swaps to avoid labeling bias.