Project description:The standard treatment for patients with diffuse large B-cell lymphoma (DLBCL) is the immunochemotherapy-based R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone). Resistance to treatment, intrinsic or acquired, is observed in approximately 40% of patients with DLBCL, who thus require novel interventions to survive. To identify biomarkers for cytotoxic response assessment, microRNAs (miRNAs) associated with doxorubicin sensitivity were determined by combining global miRNA expression profiling with systematic dose-response screens in 15 human DLBCL cell lines. One candidate, miR-34a, was tested in functional in vitro studies and in vivo in a retrospective clinical cohort. High expression of miR-34a was observed in cell lines sensitive to doxorubicin, and upregulation of miR-34a is documented here to increase doxorubicin sensitivity in in vitro lentiviral transduction assays. High expression of miR-34a had a prognostic impact using overall survival as outcome. With risk stratification of DLBCL samples based on resistance gene signatures (REGS), doxorubicin-responsive samples had statistically significant upregulated miR-34a expression. Classification of the DLBCL samples into subset-specific B cell-associated gene signatures (BAGS) revealed differentiation-specific expression of miR-34a. Our data further support FOXP1 as a target of miR-34a, suggesting that downregulation of FOXP1 may sensitize DLBCL cells to doxorubicin. We conclude that miRNAs, in particular miR-34a, may have clinical utility in DLBCL patients as both predictive and prognostic biomarkers.
Project description:Current staging classifications do not accurately predict the benefit of high-dose chemotherapy (HDC) with autologous stem-cell transplantation (ASCT) for patients with diffuse large B-cell lymphoma (DLBCL) at high risk (age-adjusted International Index [aaIPI] score 2 or 3), who have achieved first complete remission after R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone) treatment. We aim to construct a genetic prognostic model for improving individualized risk stratification and response prediction for HDC/ASCT therapy. We identified differentially expressed mRNAs associated with relapse of DLBCL.
Project description:Diffuse large B-cell lymphoma (DLBCL) is a molecularly and pathogenically heterogenous disease with varying clinical outcomes which is reflected in the substantial group of patients developing relapse/refractory disease (rrDLBCL) after standard treatment with the combinatory regimen R-CHOP. The molecular background of developing rrDLBCL is yet to be fully understood and prognostic and/or companion diagnostic biomarkers for identification, treatment stratification and prediction of adverse treatment effects of these patients are in high demand. Therefore, this exploratory study aims to use comprehensive proteomic relative quantitative data to identify proteins that are associated with treatment response. Proteome profiles of untreated DLBCL cells were analyzed by groupwise comparison between cell lines having poor and good response to rituximab, cyclophosphamide, doxorubicin and vincristine, respectively, determined by subsequent drug response screen.
Project description:Despite the long-standing role of standard chemotherapy in human diffuse large B cell lymphoma (DLBCL), the basis for individual tumor responses and how they associate with different transcriptional programs are incompletely understood. Hence we aimed to classify DLBCL cell lines by their ability to undergo therapy-induced senescence (TIS) in response to adriamycin (aka doxorubicin) and acquire gene expression profiles before and after chemotherapy by RNA-seq.
Project description:Doxorubicin response in diffuse large B-cell lymphoma cell lines varies with concentration, exposure duration, and level of intrinsic sensitivity
Project description:MicroRNAs (miRNAs or miRs) are small, noncoding RNAs that are implicated in the regulation of nearly all biological processes. Global miRNA biogenesis is altered in many cancers and RNA-binding proteins (RBPs) have been shown to play a role in this process, presenting a promising avenue for targeting miRNA dysregulation in disease. miR-34a exhibits tumor-suppressive functions by targeting cell cycle regulators CDK4/6 and anti-apoptotic factor Bcl-2, among other regulatory pathways such as Wnt, TGF-, and Notch signaling. Many cancers show downregulation or loss of miR-34a, and synthetic miR-34a supplementation has been shown to inhibit tumor growth in vivo; however, the post-transcriptional mechanisms by which miR-34a is lost in cancer are not entirely understood. Here, we have used a proteomics-mediated approach to identify Squamous cell carcinoma antigen recognized by T-cells 3 (SART3) as a putative pre-miR-34a-binding protein. SART3 is a spliceosome recycling factor and nuclear RBP with no previously reported role in miRNA regulation. We demonstrate that SART3 binds pre-miR-34a with specificity over pre-let-7d and begin to elucidate a new functional role for this protein in non-small lung cancer cells. Overexpression of SART3 led to increased miR-34a levels, downregulation of the miR-34a target genes CDK4 and CDK6, and cell cycle arrest in the G1 phase. In vitro binding studies showed that the RNA-recognition motifs within the SART3 sequence are responsible for selective pre-miR-34a binding. Collectively, our results present evidence for an influential role of SART3 in miR-34a biogenesis and cell cycle progression.
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common aggressive non-Hodgkin lymphoma, demonstrates significant molecular heterogeneity and suboptimal clinical outcomes. Notably, 10%-15% of patients develop primary refractory disease following first-line R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) regimen. While epigenetic modulators have emerged as potential therapeutic options for these high-risk cases, clinical application of broad-spectrum DNA methyltransferase inhibitors such as decitabine and azacitidine remains limited by their multi-target toxicity profiles. In this study, we demonstrated that DNA methyltransferase 1 (DNMT1) plays a critical oncogenic role in DLBCL pathogenesis.
Project description:Diffuse large B-cell lymphoma (DLBCL), the most common aggressive non-Hodgkin lymphoma, demonstrates significant molecular heterogeneity and suboptimal clinical outcomes. Notably, 10%-15% of patients develop primary refractory disease following first-line R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) regimen. While epigenetic modulators have emerged as potential therapeutic options for these high-risk cases, clinical application of broad-spectrum DNA methyltransferase inhibitors such as decitabine and azacitidine remains limited by their multi-target toxicity profiles. In this study, we demonstrated that DNA methyltransferase 1 (DNMT1) plays a critical oncogenic role in DLBCL pathogenesis.