Drug resistance in diffuse large B-cell lymphoma

An interpretable survival model for diffuse large B-cell lymphoma patients using a biologically informed visible neural network

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL) and is characterized by high heterogeneity. Assessment of its prognosis and genetic subtyping hold significant clinical implications. However, existing DLBCL prognostic models are mainly based on transcriptomic profiles, while genetic variation detection is more commonly used in clinical practice. In addition, current clustering-based subtyping methods mostly focus on genes with high mutation frequencies, providing insufficient explanations for the heterogeneity of DLBCL. Here, we proposed VNNSurv (https://bio-web1.nscc-gz.cn/app/VNNSurv), a survival model for DLBCL patients based on a biologically informed visible neural network (VNN). VNNSurv achieved an average C-index of 0.72 on the cross-validation set (HMRN cohort, n = 928), outperforming the baseline methods. The remarkable interpretability of VNNSurv facilitated the identification of the most impactful genes and the underlying pathways through which they act on patient outcomes. When only the 30 highest-impact genes were used as genetic input, the overall performance of VNNSurv improved, and a C-index of 0.70 was achieved on the external TCGA cohort (n = 48). Leveraging these high-impact genes, including 16 genes with low (<5 %) alteration frequencies, we devised a genetic-based prognostic index (GPI) for risk stratification and a subtype identification method. We stratified the patient group according to the International Prognostic Index (IPI) into three risk grades with significant prognostic differences. Furthermore, the defined subtypes exhibited greater prognostic consistency than clustering-based methods. Broadly, VNNSurv is a valuable DLBCL survival model. Its high interpretability has significant value for precision medicine, and its framework is scalable to other diseases.

RNA-seq and integrated network analysis reveals the hub genes and key pathway of paclitaxel inhibition on Adriamycin resistant diffuse large B cell lymphoma cells

About 40% of patients with diffuse large B-cell lymphoma (DLBCL) develop drug resistance after first-line chemotherapy, which remains a major cause of morbidity and mortality. The emergence of DLBCL drug resistance is mainly related to Adriamycin. Our previous research shows that Paclitaxel could be a potential therapeutic drug for the treatment of Adriamycin-resistant DLBCL. Based on the results of RNA-seq and integrated network analysis, we study the potential molecular mechanism of Paclitaxel in the treatment of Adriamycin-resistant DLBCL in multiple dimensions. A CCK-8 assay showed that the inhibitory effect of Paclitaxel on Pfeiffer and Pfeiffer/ADM (Adriamycin-resistant DLBCL cell lines) is significantly higher than that of Adriamycin (P ＜ 0.05). Five hub genes (UBC, TSR1, WDR46, HSP90AA1, and NOP56) were obtained via network analysis from 971 differentially expressed genes (DEGs) based on the RNA-seq of Paclitaxel-intervened Pfeiffer/ADM. The results of the network function module analysis showed that the inhibition of Pfeiffer/ADM by Paclitaxel was closely related to ribosome biosynthesis in eukaryotes. The results of RT-qPCR showed that the mRNA levels of the five hub genes in the Pfeiffer/ADM group were significantly lower than those in the Pfeiffer group and the Pfeiffer/ADM Paclitaxel-treated group (P ＜ 0.05). Consistent with studies, Paclitaxel exhibited a significant inhibitory effect on Adriamycin-resistant DLBCL, which may have played a role in the five hub genes (UBC, TSR1, WDR46, HSP90AA1 and NOP56) and ribosome biosynthesis in eukaryotes pathway, but the specific regulation needs further experimental verification.

Rituximab with dose-adjusted EPOCH as first-line treatment in patients with highly aggressive diffuse large B-cell lymphoma and autologous stem cell transplantation in selected patients

AIM

To assess the benefit of rituximab with dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (R-DA-EPOCH) regimen as a first-line treatment for patients with diffuse large B-cell lymphoma (DLBCL) presenting with unfavorable or aggressive features, and autologous stem cell transplantation (ASCT) as a part of the first-line treatment for selected DLBCL patients with additional aggressive features.

METHODS

We retrospectively analyzed 75 newly diagnosed DLBCL patients with Ki-67+≥80% or International Prognostic Index ≥2 who were treated with R-DA-EPOCH between 2005 and 2015. Of 24 DLBCL patients with additional aggressive features (Ki-67+≥90% or age-adjusted IPI≥2) who were planned to receive consolidation with ASCT, 17 patients underwent the procedure. We determined the overall response rate (ORR), complete remission (CR), partial remission (PR), 5-year overall survival (OS), and progression free survival (PFS) in all DLBCL patients and specifically those planned to receive ASCT.

RESULTS

All 75 patients included in the analysis started one or more cycles of therapy. The ORR, CR, and PR rates were 80%, 55%, and 25%, respectively. The response was non-evaluable in 10 of 75 patients due to treatment discontinuation. The OS and PFS rates for all 75 patients were 70% and 61%, respectively, and 80% and 79%, respectively, for 24 planned-to-receive-ASCT patients. Age (≤65 vs >65 years) had no prognostic impact on OS and PFS (P=0.994 and P=0.827, respectively).

CONCLUSION

Our retrospective analysis of one of the largest DLBCL patient cohorts outside the US National Cancer Institute showed that R-DA-EPOCH is a very effective therapeutic option as a first-line treatment of DLBCL patients with unfavorable prognostic features irrespective of their age. ASCT provided additional benefit for DLBCL patients with additional aggressive features.

Current Progress in EBV-Associated B-Cell Lymphomas

Epstein-Barr virus (EBV) was the first human tumor virus discovered more than 50 years ago. EBV-associated lymphomagenesis is still a significant viral-associated disease as it involves a diverse range of pathologies, especially B-cell lymphomas. Recent development of high-throughput next-generation sequencing technologies and in vivo mouse models have significantly promoted our understanding of the fundamental molecular mechanisms which drive these cancers and allowed for the development of therapeutic intervention strategies. This review will highlight the current advances in EBV-associated B-cell lymphomas, focusing on transcriptional regulation, chromosome aberrations, in vivo studies of EBV-mediated lymphomagenesis, as well as the treatment strategies to target viral-associated lymphomas.

WITHDRAWN: ALDH1A1 induces resistance to CHOP in diffuse large B-cell lymphoma through activation of the JAK2/STAT3 pathway

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ALDH1A1 induces resistance to CHOP in diffuse large B-cell lymphoma through activation of the JAK2/STAT3 pathway

Increasing evidence has shown that aldehyde dehydrogenase 1A1 (ALDH1A1), a detoxifying enzyme, is responsible for chemoresistance in a variety of tumors. Although the majority of patients with diffuse large B-cell lymphoma (DLBCL) can be cured with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), chemoresistance is a common cause of treatment failure. This study aims to investigate the significance of ALDH1A1 expression and the mechanism by which ALDH1A1 is involved in the chemoresistance of DLBCL cells. ALDH1A1 expression was assessed in 88 DLBCL tissues by immunohistochemistry. The association between ALDH1A1 expression and outcome was evaluated. We also investigated the effect of ALDH1A1 on CHOP resistance in DLBCL cells using functional analysis. ALDH1A1 expression levels were upregulated in patients with stable or progressive disease after CHOP and its expression positively correlated with expression of STAT3 and p-STAT3. In keeping with these observations, ALDH1A1 expression was significantly associated with short survival of DLBCL patients who received CHOP chemotherapy. In functional assays in Pfeiffer cells, overexpression of ALDH1A1 conferred resistance to CHOP, while silencing of ALDH1A1 using short hairpin RNA had the opposite effect. Furthermore, we also observed that ALDH1A1 could regulate the JAK2/STAT3 pathway, while inhibition of the JAK2/STAT3 pathway by WP1066 negated the effect of ALDH1A1 overexpression. These observations reveal that ALDH1A1 induces resistance to CHOP through activation of the JAK2/STAT3 pathway in DLBCL, and its targeting provides a potential strategic approach for reversing CHOP resistance.

Novel drug targets for personalized precision medicine in relapsed/refractory diffuse large B-cell lymphoma: a comprehensive review

Diffuse large B-cell lymphoma (DLBCL) is a clinically heterogeneous lymphoid malignancy and the most common subtype of non-Hodgkin's lymphoma in adults, with one of the highest mortality rates in most developed areas of the world. More than half of DLBLC patients can be cured with standard R-CHOP regimens, however approximately 30 to 40 % of patients will develop relapsed/refractory disease that remains a major cause of morbidity and mortality due to the limited therapeutic options.Recent advances in gene expression profiling have led to the identification of at least three distinct molecular subtypes of DLBCL: a germinal center B cell-like subtype, an activated B cell-like subtype, and a primary mediastinal B-cell lymphoma subtype. Moreover, recent findings have not only increased our understanding of the molecular basis of chemotherapy resistance but have also helped identify molecular subsets of DLBCL and rational targets for drug interventions that may allow for subtype/subset-specific molecularly targeted precision medicine and personalized combinations to both prevent and treat relapsed/refractory DLBCL. Novel agents such as lenalidomide, ibrutinib, bortezomib, CC-122, epratuzumab or pidilizumab used as single-agent or in combination with (rituximab-based) chemotherapy have already demonstrated promising activity in patients with relapsed/refractory DLBCL. Several novel potential drug targets have been recently identified such as the BET bromodomain protein (BRD)-4, phosphoribosyl-pyrophosphate synthetase (PRPS)-2, macrodomain-containing mono-ADP-ribosyltransferase (ARTD)-9 (also known as PARP9), deltex-3-like E3 ubiquitin ligase (DTX3L) (also known as BBAP), NF-kappaB inducing kinase (NIK) and transforming growth factor beta receptor (TGFβR).This review highlights the new insights into the molecular basis of relapsed/refractory DLBCL and summarizes the most promising drug targets and experimental treatments for relapsed/refractory DLBCL, including the use of novel agents such as lenalidomide, ibrutinib, bortezomib, pidilizumab, epratuzumab, brentuximab-vedotin or CAR T cells, dual inhibitors, as well as mechanism-based combinatorial experimental therapies. We also provide a comprehensive and updated list of current drugs, drug targets and preclinical and clinical experimental studies in DLBCL. A special focus is given on STAT1, ARTD9, DTX3L and ARTD8 (also known as PARP14) as novel potential drug targets in distinct molecular subsets of DLBCL.

MicroRNA-21 regulates the sensitivity of diffuse large B-cell lymphoma cells to the CHOP chemotherapy regimen

Numerous studies have demonstrated that microRNA-21 (miR-21), as an oncogene, is involved in the occurrence of many types of tumor and the sensitivity of tumor cells to chemotherapeutic drugs. In the present study, we investigated whether miR-21 is involved in regulating the sensitivity of the diffuse large B-cell lymphoma (DLBCL) cell line CRL2631 to the cyclophosphamide, vincristine, Adriamycin, and prednisone (CHOP) chemotherapeutic regimen. Knockdown of miR-21 with antisense oligonucleotides significantly increased the cytotoxic effects of the CHOP regimen in CRL2631 cells. A luciferase reporter assay showed that PTEN is a target gene of miR-21 in CRL2631 cells, and subsequent experiments demonstrated that miR-21 impacts the PI3K/AKT signaling pathway through the regulation of PTEN, thereby affecting cellular sensitivity to the CHOP chemotherapeutic regimen. Furthermore, knockdown of NF-κB decreased miR-21 expression and sensitized CRL2631 cells to CHOP treatment. These results provide evidence that it may be possible to overcome microRNA-based DLBCL drug resistance.

A Cancer and Leukemia Group B multi-center study of DA-EPOCH-rituximab in untreated diffuse large B-cell lymphoma with analysis of outcome by molecular subtype

BACKGROUND

A phase II trial of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab (DA-EPOCH-R) from the National Cancer Institute showed promising activity in untreated diffuse large B-cell lymphoma. The Cancer and Leukemia Group B conducted a study to determine if these results could be reproduced in a multi-institutional setting.

DESIGN AND METHODS

The study included 69 patients with untreated diffuse large B-cell lymphoma at least 18 years of age and at least stage II. Radiaton therapy was not permitted on study. Median age was 58 years (range 23-83) and 40% had high-intermediate or high International Prognostic Index risk. Immunohistochemical biomarkers for cell of origin and proliferation were performed.

RESULTS

With a median follow up of 62 months, time to progression and overall survival were 81% and 84%, respectively, and time to progression was 87%, 92% and 54% for low/low-intermediate, high-intermediate and high International Prognostic Index risk groups, respectively, at 5-years and beyond. The time to progression and event-free survival of germinal center B-cell lymphoma were 100% and 94%, respectively, and non-germinal center B-cell GCB diffuse large B-cell lymphoma were 67% and 58%, respectively, at 62 months (germinal center vs. non-germinal center B cell P=0.008). DA-EPOCH-R was tolerated without significant grade 4 non-hematologic toxicities.

CONCLUSIONS

These results provide the first confirmation by a multi-institutional group that DA-EPOCH-R provides high durable remissions in diffuse large B-cell lymphoma and is effective in both germinal center and non-germinal center B-cell subtypes. The trial was registered at ClinicalTrials.Gov (NCT00032019).

Immunotoxin BL22 induces apoptosis in mantle cell lymphoma (MCL) cells dependent on Bcl-2 expression

Mantle cell lymphoma (MCL) is an incurable mature B cell proliferation, combining the unfavourable clinical features of aggressive and indolent lymphomas. The blastic variant of MCL has an even worse prognosis and new treatment options are clearly needed. We analysed the effects of BL22, an immunotoxin composed of the Fv portion of an anti- CD22 antibody fused to a 38-kDa Pseudomonas exotoxin-A fragment on four MCL cell lines as well as on primary cells of four MCL patients. Apoptosis induction by BL22 was much more pronounced in MCL cell lines with low Bcl-2 expression (NCEB-1, JeKo-1 and JVM-2) compared to Granta-519 cells with high Bcl-2 expression. While the expression of the antiapoptotic protein Mcl-1 declined (NCEB-1, Granta-519), Bcl-2 levels remained unchanged in Granta-519 cells. However transfection of BCL2 cDNA into NCEB-1, JeKo-1 and JVM-2 cells significantly reduced BL22-mediated toxicity. Accordingly we examined the effects of Bcl-2 inactivation in Granta-519 cells using siRNA. Indeed, apoptosis induction was strongly enhanced in Granta-519 cells with silenced Bcl-2. Our results were confirmed in freshly isolated MCL-cells from patients with leukaemic MCL. We conclude that Bcl-2 expression is important for mediating resistance against the immunotoxin BL22 in MCL cells.

Structural profiles of TP53 gene mutations predict clinical outcome in diffuse large B-cell lymphoma: an international collaborative study

The purpose of this study is to correlate the presence of TP53 gene mutations with the clinical outcome of a cohort of patients with diffuse large B-cell lymphoma (DLBCL) assembled from 12 medical centers. TP53 mutations were identified in 102 of 477 patients, and the overall survival (OS) of patients with TP53 mutations was significantly worse than those with wild-type TP53 (P < .001). However, subsets of TP53 mutations were found to have different effects on OS. Mutations in the TP53 DNA-binding domains were the strongest predictors of poor OS (P < .001). Mutations in the Loop-Sheet-Helix and Loop-L3 were associated with significantly decreased OS (P = .002), but OS was not significantly affected by mutations in Loop-L2. A subset of missense mutations (His158, His175, Ser245, Gln248, His273, Arg280, and Arg282) in the DNA-binding domains had the worst prognosis. Multivariate analysis confirmed that the International Prognostic Index and mutations in the DNA-binding domains were independent predictors of OS. TP53 mutations also stratified patients with germinal center B cell-like DLBCL, but not nongerminal center B cell-like DLBCL, into molecularly distinct subsets with different survivals. This study shows the prognostic importance of mutations in the TP53 DNA-binding domains in patients with DLBCL.

Phase II study of dose-adjusted EPOCH and rituximab in untreated diffuse large B-cell lymphoma with analysis of germinal center and post-germinal center biomarkers

PURPOSE

To assess the clinical outcome and the influence of biomarkers associated with apoptosis inhibition (Bcl-2), tumor proliferation (MIB-1), and cellular differentiation on the outcome with dose-adjusted (DA) EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) plus rituximab (R) infusional therapy in diffuse large B-cell lymphoma (DLBCL) with analysis of germinal center B-cell (GCB) and post-GCB subtypes by immunohistochemistry.

PATIENTS AND METHODS

Phase II study of 72 patients with untreated de novo DLBCL who were at least 18 years of age and stage II or higher. Radiation consolidation was not permitted.

RESULTS

Patients had a median age of 50 years (range, 19 to 85) and 40% had a high-intermediate or high International Prognostic Index (IPI). At 5 years, progression-free survival (PFS) and overall survival (OS) were 79% and 80%, respectively, with a median potential follow-up of 54 months. PFS was 91%, 90%, 67%, and 47%, and OS was 100%, 90%, 74%, and 37%, for 0 to 1, 2, 3, and 4 to 5 IPI factors, respectively, at 5 years. The Bcl-2 and MIB-1 biomarkers were not associated with PFS or OS. Based on DA-EPOCH historical controls, rituximab only benefited Bcl-2 positive tumors. Bcl-6 expression was associated with higher PFS whereas GCB exhibited a marginally significant higher PFS compared with post-GCB DLBCL.

CONCLUSION

DA-EPOCH-R outcome was not affected by tumor proliferation and rituximab appeared to overcome the adverse effect of Bcl-2. Bcl-6 may identify a biologic program associated with a superior outcome. Overall, DA-EPOCH-R shows promising outcome in low and intermediate IPI groups. A molecular model of treatment outcome with rituximab and chemotherapy is presented.