scholarly journals Accelerated Degradation of cFLIP Mediated By Inhibition of Methyltransferases Sensitizes B-Cell Lymphoma Cells to TRAIL-Induced Apoptosis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 920-920
Author(s):  
Frank K Braun ◽  
Rohit Mathur ◽  
Lalit Sehgal ◽  
Rachel Wilkie-Grantham ◽  
Joya Chandra ◽  
...  

Abstract Introduction Non-Hodgkin lymphomas (NHLs) are characterized by specific abnormalities that alter cell cycle regulation, DNA damage response, and apoptotic signaling. Cancer cells can be particularly sensitive to cell death induced by tumor necrosis factor a–related apoptosis-inducing ligand (TRAIL). However, many cancer cells show blocked TRAIL signaling because up-regulated expression of anti-apoptotic factors such as cFLIP. Thus, by further understanding the underpinnings of apoptosis resistance, we will be in a better position to develop strategies that improve TRAIL-induced killing of lymphoma cells. Methods/Results NHL cell lines, including mantle cell lymphoma (MCL; Mino, JeKo-1, JVM-2 and Z-138), Burkitt lymphoma (BL; Bjab, Ramos, Daudi) and diffuse large B-cell lymphoma (DLBCL; SU-DHL-4, SU-DHL -6, SU-DHL-9) were treated with 3-Deazaneplanocin A (DZNep); 0.2-5µM) for 24 hours followed by incubation with TRAIL (10-20ng/ml, 6-16hours). Cell death, DNA fragmentation, and mitochondrial membrane potential (Δψm) were determined by calcein staining, subG1 analysis, and TMRM staining, respectively. Neither DZNep alone nor in combination with TRAIL showed a significant induction of necrosis as determined by LDH-release levels, but DZNep alone showed strong anti-proliferative properties at higher concentrations. Activation of the caspase signaling cascade (caspase-8, -3, and PARP cleavage) was analyzed by Western blotting. TRAIL-induced signaling was significantly increased and caspase-8 processing enhanced in DZNep pretreated cells indicating a regulation at the TRAIL/DISC assembly. Although we observed a reduced expression of DR5 in total cell lysates of DZNep treated cells, the surface receptor levels were not altered. Interestingly, down regulation of the well-known caspase inhibitor, cFLIP, correlated with the DZNep-induced increased TRAIL cell killing in all sensitive NHL cells. The DZNep-treatment did not block NF-kB signaling related to cFLIP expression but profoundly affected cFLIP mRNA and protein stability. Elevated levels of cFLIP targeting miRNA’s were observed and were attributed to some extend with cFLIP regulation. Conclusions: In this study, we investigated the impact of a pan-methyltransferase inhibitor (3-deazaneplanocin A, or DZNep) on TRAIL-induced apoptosis in aggressive NHLs: mantle cell, Burkitt, and diffuse large B-cell. We characterized TRAIL apoptosis regulation and caspase activation in several NHL cell lines pre-treated with DZNep. We found that DZNep increased cancer cell sensitivity to TRAIL signaling by promoting caspase-8 processing through accelerated cFLIP degradation. Blockage of methyltransferase activity induced by DZNep profoundly affected cFLIP mRNA and protein stability, at least in part through increased levels of cFLIP-targeting microRNAs (miR-512-3p and miR-346). However, additional microRNAs and cFLIP-regulating mechanisms appear to be involved in DZNep-mediated enhanced response to extrinsic apoptotic stimuli. The capacity of DZNep to target cFLIP expression on multiple levels underscores its potential in TRAIL-based therapies for NHLs. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2009 ◽  
Vol 114 (20) ◽  
pp. 4503-4506 ◽  
Author(s):  
Anja Mottok ◽  
Christoph Renné ◽  
Marc Seifert ◽  
Elsie Oppermann ◽  
Wolf Bechstein ◽  
...  

Abstract STATs are constitutively activated in several malignancies. In primary mediastinal large B-cell lymphoma and Hodgkin lymphoma (HL), inactivating mutations in SOCS1, an inhibitor of JAK/STAT signaling, contribute to deregulated STAT activity. Based on indications that the SOCS1 mutations are caused by the B cell–specific somatic hypermutation (SHM) process, we analyzed B-cell non-HL and normal B cells for mutations in SOCS1. One-fourth of diffuse large B-cell lymphoma and follicular lymphomas carried SOCS1 mutations, which were preferentially targeted to SHM hotspot motifs and frequently obviously inactivating. Rare mutations were observed in Burkitt lymphoma, plasmacytoma, and mantle cell lymphoma but not in tumors of a non–B-cell origin. Mutations in single-sorted germinal center B cells were infrequent relative to other genes mutated as byproducts of normal SHM, indicating that SOCS1 inactivation in primary mediastinal large B-cell lymphoma, HL, diffuse large B-cell lymphoma, and follicular lymphoma is frequently the result of aberrant SHM.


2019 ◽  
Vol 120 (12) ◽  
pp. 1137-1146 ◽  
Author(s):  
Anke Maes ◽  
Ken Maes ◽  
Hendrik De Raeve ◽  
Eva De Smedt ◽  
Philip Vlummens ◽  
...  

2012 ◽  
Vol 61 (4) ◽  
pp. 685-693 ◽  
Author(s):  
Shih-Chuan Hsiao ◽  
Inmaculada Ribera Cortada ◽  
Luis Colomo ◽  
Hongtao Ye ◽  
Hongxiang Liu ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 242-242 ◽  
Author(s):  
Hovav Nechushtan ◽  
Joseph D. Rosenblatt ◽  
Izidore S. Lossos

Abstract Diffuse Large B-cell Lymphoma (DLBCL) represent a diverse group of lymphoid neoplasms with heterogeneous clinical, histological, immunophenotypic, cytogenetic and molecular genetic features. Approximately 50% of DLBCL patients are not cured by the standard combination chemotherapy regimens. DLBCL can be subclassified into GCB-like DLBCL which are characterized by expression of genes normally expressed in germinal center B cells, and having a significantly better overall survival (OS) than the ABC-like DLBCL, which are characterized by expression of genes induced during in vitro activation of normal B cells. At least two markers of the GCB-phenotype - BCL6 and HGAL - are IL-4 target genes, increased expression of which independently predicts better OS. These observations suggest that endogenous or exogenously administered IL-4 may influence behavior of DLBCL. IL-4 mRNA was detected at low levels in 5 of 7 GCB-like and in all 4 ABC-like DLBCL tumor specimens. Two of 7 GCB-like tumors showed high expression levels of IL-4 as determined by real-time RT-PCR. Examination of the effects of IL-4 on proliferation of GCB-like (SUDHL6, SUDHL4 and OCILY19) and ABC-like (OCILY10 and OCILY3) DLBCL cell lines showed that IL-4 mildly increased DNA synthesis, as assessed by thymidine incorporation, in all the GCB-like DLBCL. Conversely, IL-4 markedly decreased proliferation in the ABC-like DLBCL cell lines by inducing G1 arrest. IL-4 also differently affected the sensitivity of GCB-like and ABC-like DLBCL to doxorubicin. IL-4 reduced doxorubicin-induced cell death of ABC-like cell lines (20–50% reduction) while it markedly increased the killing of the GCB-like cells (40–80% induction). IL-4 also prevented serum starvation-induced cell death of the ABC-like DLBCL, but it increased cell death of the GCB-like DLBCL cell lines. Recently, Rituximab was shown to improve survival of DLBCL patients when added to the CHOP regimen. The precise mechanisms of its action are unknown; however present data suggest that it may affect lymphoma cells either by activation of complement lysis or by mediating ADCC. IL-4 reduced the complement mediated Rituximab cell lysis of the ABC-like cell lines, while it increased the complement mediated Rituximab cell lysis of the GCB-like DLBCL cell lines. Expression levels of surface markers that modulate complement cell lysis (CD46, CD55 and CD59) were not affected by IL-4 exposure. In contrast, IL-4 did not affect killing of GCB-like and ABC-like cells by ADCC. These observations suggest that DLBCL subtypes may respond differently to the in vivo cytokine milieu of the tumor. Different responsiveness to IL-4 may modulate tumor sensitivity to the current therapeutic modalities and can potentially be explored to augment response to chemotherapy and Rituximab.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4655-4655
Author(s):  
James A. Strauchen ◽  
David Burstein

Abstract X-linked inhibitor of apoptosis protein (XIAP) is an important regulator of apoptosis which binds to and inhibits caspases-3, -7 and -9, blocking the caspase 9-mediated apoptosis pathway. This pathway is activated by p53 and DNA damage and may be an important determinant of responsiveness to chemotherapy. Apoptosis also plays a major role in the regulation of follicle center B-cell proliferation and BCL2-mediated inhibition of apoptosis is a key factor in B-cell lymphomagenesis. In this study we examined the expression of XIAP in 65 reactive and neoplastic lymphoid proliferations utilizing a monoclonal antibody to XIAP (#610763 BD Biosciences, San Jose, CA) and immunohistochemistry with avidin-biotin-complex immunoperoxidase technique on formalin-fixed, paraffin-embedded sections. In reactive lymph nodes and tonsils, expression of XIAP was limited to large noncleaved cells in follicle centers (5 of 6 cases). XIAP was absent in plasmacytoma (3 cases) and small lymphocytic lymphoma/chronic lymphocytic leukemia (1 case). XIAP was expressed in follicular lymphoma, predominantly in large noncleaved cells (6 of 9 cases) and in diffuse large B cell lymphoma (11 of 16 cases), including cases of T-cell/histiocyte-rich diffuse large B cell lymphoma (2 cases), primary mediastinal large B cell lymphoma (1 case), and posttransplantation diffuse large B cell lymphoma (1 case). XIAP was consistently expressed in Burkitt and Burkitt-like lymphoma (3 of 3 cases) and anaplastic large cell lymphoma (3 of 3 cases) and in one case of adult T cell leukemia/lymphoma. XIAP was variably expressed in marginal-zone B cell lymphoma, predominantly in large blasts (2 of 4 cases) and in mantle cell lymphoma (2 of 3 cases). XIAP was not detected in peripheral T cell lymphoma, unspecified (1 case), extranodal NK/T cell lymphoma, nasal type (1 case), precursor B cell lymphoblastic leukemia (1 case), or granulocytic sarcoma (1 case). XIAP was consistently expressed in the Reed-Sternberg and mononuclear Reed-Sternberg-variant cells of classical Hodgkin disease (9 of 9 cases) and the L+H Reed-Sternberg-variant cells of nodular lymphocyte predominance Hodgkin disease (3 of 3 cases). XIAP is expressed across a broad range of lymphoproliferative disorders, including classical and nodular lymphocyte predominance Hodgkin disease, diffuse large B cell lymphoma, follicular lymphoma, Burkitt lymphoma, marginal-zone and mantle cell lymphoma, and anaplastic large cell lymphoma. XIAP appears to be selectively expressed in the proliferating elements of these lymphomas. The possible prognostic and therapeutic significance of XIAP expression needs to be determined.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2681-2681 ◽  
Author(s):  
Anne W Beaven ◽  
David A. Rizzieri ◽  
Zachary Powell ◽  
Zhiguo Li ◽  
Peggy Alton ◽  
...  

Abstract Abstract 2681 Background: Despite recent advances, the 5 year overall survival for patients with high risk diffuse large B cell lymphoma (DLBCL) is approximately 50% and there is still no known cure for patients with mantle cell lymphoma (MCL). This phase II study of multimodal dose dense therapy evaluated 2 courses of dose intense chemotherapy followed by radioimmunotherapy (RIT) consolidation in patients with previously untreated, mantle cell or high/high intermediate (int) risk aggressive B cell lymphoma. Aim: To evaluate the efficacy and safety of dose intense/dose dense, multimodal chemo-immunotherapy combined with RIT. Methods: Patients with untreated MCL or high int/high risk DLBCL were enrolled. Treatment regimen involved 3 phases of therapy: induction 1, induction 2 and consolidation with RIT (Table 1). Induction 2 occurred approximately 5 weeks after induction 1 and RIT was given 12–24 weeks after rituximab was completed. Patients were evaluated after each treatment phase and those with stable disease (SD) or better and blood count recovery could proceed to the next phase of therapy. Results: Thirty nine patients (pts) with high/high int risk DLBCL (n=25) or MCL (n=14) were enrolled. The median age was 60 years (range 21–80). Toxicity: Common, anticipated toxicities in the induction phases were thrombocytopenia, neutropenia, nausea, fatigue, and anemia. During Ind1 (n=39), grade (gr) III mucositis occurred in 13 pts (33%) and febrile neutropenia (FN) in 31 (79%). Three pts did not proceed to Ind2 due to death (1 candidemia, 1 septic knee prosthesis, 1 from complications of colectomy for prolonged diverticulitis after count recovery) and 2 withdrew to pursue less intense chemotherapy. During Ind2 (n=34) gr III mucositis occurred in 12pts (35%) and FN in 24 (67%). Two pts had gr III/IV cerebellar toxicity that was disabling in 1 pt. Of the 34 pts who received the Ind2, 9 did not receive RIT due to progressive disease (PD) (4), prolonged cytopenias (4), or diagnosis of pancreatic cancer (1). Twenty five pts received RIT and 3 (12%) had FN, 20 (80%) had gr III/IV neutropenia, 23 (92%) had gr III/IV thrombocytopenia, 1 pt died from bacteremia. Two pts developed myelodysplasia 21 and 48 months after starting therapy. Response: Pts were evaluated for response after Ind1, Ind2 and RIT. 38/39 pts were evaluable for response, with 1 pt withdrawing prior to assessment. The pts who died prior to response evaluation were counted as non-responders. The best overall response rate (ORR) was 95% (36/38) with a complete response rate (CR) of 84% (32/38). See tables 2 and 3 for more detailed response data by phase of treatment and disease type. After a median follow up of 17.2 months, 30 pts (77%) are alive (see figure). The median overall survival for MCL has not been reached and is 36.5 months for DLBCL. Deaths were from Hodgkin lymphoma (1), infection (3), DLBCL (2), complications of surgery (1), MCL (2). The median progression free survival is 36.5 months with 11/14 (79%) MCL and 14/25 (56%) DLBCL pts alive and in continued CR. Conclusion: The combination of dose dense, dose intense chemotherapy, monoclonal antibody, and RIT demonstrates considerable efficacy, despite expected toxicity, in high risk DLBCL and MCL pts. The response rates seen in this study are higher than expected from standard R-CHOP in this pt population. Further follow up to determine impact on OS and long term complications will be required to confirm these promising outcomes. Disclosures: Beaven: Glaxo Smith Kline: Family Member Employed by GSK. Off Label Use: Tositumomab is approved for use in relapsed/refractory low grade CD20 positive NHL. It is not FDA approved for first line use in diffuse large B cell lymphoma or mantle cell lymphoma. Neither cytarabine nor etoposide are approved for use in non-Hodgkin lymphoma. Rizzieri:Glaxo Smith Kline: Speakers Bureau. Moore:Glaxo Smith Kline: Speakers Bureau.


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