scholarly journals Inhibition of LINK-A lncRNA overcomes ibrutinib resistance in mantle cell lymphoma by regulating Akt/Bcl2 pathway

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12571
Author(s):  
Ye Zhang ◽  
Peng Lu ◽  
Yan Zhou ◽  
Lifei Zhang
Keyword(s):  
Cell Viability ◽  
B Cell ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Cell Lymphoma ◽  
Akt Signaling ◽  
Mantle Cell ◽  
Ibrutinib Resistance ◽  
Bcl2 Expression

Ibrutinib, a bruton tyrosine kinase (BTK) inhibitor which suppresses B-cell receptor signaling, has remarkably improved the outcome of patients with mantle cell lymphoma (MCL). However, approximately 33% of MCL patients have primary Ibrutinib resistance, and acquired Ibrutinib resistance is nearly universal. Long intergenic non-coding RNA for kinase activation (LINK-A) exerts oncogenic role in different types of tumors, but the role of LINK-A in intrinsic ibrutinib resistance in MCL is still unclear. Here, LINK-A expression level was first assessed using quantitative Real-time PCR (qPCR) and immunofluorescence analysis in five MCL cell lines. The effect of LINK-A on regulating MCL cells viability and apoptosis was assayed using CCK-8 and TdT-mediated dUTP nick end labeling (TUNEL) assay, respectively. The association of LINK-A with AKT activation and B cell lymphoma 2 (Bcl2)expression was evaluated using qPCR and western blot analysis. We found that LINK-A level was elevated in Ibrutinib-resistant MCL cell lines (Mino, REC-1, MAVER-1, and Granta-519) compared to Ibrutinib-sensitive MCL cell lines (Jeko-1). Functionally, LINK-A overexpression in Jeko-1 cells enhanced cell viability and repressed Ibrutinib-induced cell apoptosis. LINK-A knockdown in MAVER-1 cells decreased cell viability and further accelerated Ibrutinib-induced cell apoptosis. LINK-A overexpression enhanced Bcl2 expression in Jeko-1 cells, and Bcl2 inhibition blocked the effect of LINK-A on increasing cell viability in the presence of Ibrutinib. On the contrary, LINK-A knockdown reduced Bcl2 expression in MAVER-1 cells, and Bcl2 overexpression damaged the role of LINK-A inhibition in regulating cell viability. Mechanistically, LINK-A positively regulated the activation of AKT signaling, and inhibition of AKT signaling destroyed LINK-A-induced increased of Bcl2 and resulted in a subsequent suppression of cell viability. Taken together, the current results demonstrate that LINK-A inhibition overcomes Ibrutinib resistance in MCL cells by regulating AKT/Bcl2 pathway.

A Novel Long Non-Coding RNA, SNHG4 Complex With Eukaryotic Initiation Factor-4E and Regulate Aberrant Protein Translation In Mantle Cell Lymphoma: Implications For Novel Biomarker

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 81-81
Author(s):  
Guangzhen Hu ◽  
Thomas E Witzig ◽  
Mamta Gupta
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Rna Binding ◽  
Cell Lymphoma ◽  
Protein Translation ◽  
Rna Seq ◽  
Lymphoma Cells ◽  
Binding Motifs ◽  
Mantle Cell

Abstract Long noncoding RNAs (lncRNAs) are defined as RNA-like transcripts that are over 200 nucleotides and lack significant open reading frames. Some lncRNAs such as HOTAIR, MALAT1 and H19 have been found to be associated with clinical prognosis and are potential drivers of cancer progression in cancers of the breast, lung, and liver respectively. The role of lncRNAs in lymphoma is unknown. Dysregulation of eIF4E (a key component of the translation initiation complex eIF4F) influences global protein translation, especially the translation of “weak” mRNAs that can be malignancy-related. We and others have found that eIF4E is dysregulated in B-cell lymphoma. The aim of this study is to identify eIF4E-associated lncRNAs through next generation RNA-Sequencing (NGS RNA-Seq) and delineate their role in protein translation in lymphoma. RNA-immunoprecipitation (RNA-IP) was used to pull down eIF4E-bound lncRNA in lymphoma cells. eIF4E-bound lncRNAs were immunoprecipitated with eIF4E antibody or IgG control in Jeko, a mantle cell lymphoma (MCL) cell line and sent for microarray analysis and NGS-RNA-Seq for identification of lncRNAs. The microarray analysis showed that several lncRNAs were enriched with eIF4E antibody compared to IgG control. These included SNHG4 (13.6 fold), SNHG12 (4.8 fold), NCRNA00171 (4.8 fold) and IPW (4.6 fold), GNASAS (3.5 fold), SNHG7 (3.3 fold), NCRNA00182 (2.7 fold), NCRNA00094 (2.6 fold), NCRNA00188 (2.4 fold) and NCRNA00201 (2.1 fold). The binding of these lncRNAs to eIF4E was further confirmed by RT-PCR in Jeko, Mino and Granta MCL cell lines. Next, we looked the expression of these lncRNAs by qRT- PCR in the MCL cell lines and normal controls. We found SNHG4 and IPW to be overexpressed in all the MCL cell lines, while SNHG12 and NCRNA00201 were overexpressed in the selected cell lines. No significant difference was found for the expression of NCRNA00171 and NCRNA00182 in any of the MCL cell lines compared to controls. Overall, these data suggest that several lncRNA have altered expression in malignant B-cells. Considering that the microarray assay only covered a limited number of lncRNAs, we further confirmed eIF4E bound lncRNA by NGS RNA-Seq in Jeko MCL and normal control. The binding of 10/13 lncRNA mentioned above with eIF4E were found upregulated by NGS-RNA-Seq. In addition several novel lncRNAs such as SNHG1 (161.6), AC091814.2 (98.8) and RP11-304L19.5 (64.2) showed up in NGS-RNA-Seq data. These data suggest that lncRNAs, such as SNHG12, SNHG4, and SNHG1 bind to eIF4E with high affinity in malignant B-cells and might play a role in protein translation. We knocked down the expression of SNHG4 through siRNA and demonstrated that cell proliferation and global protein translation was inhibited in lymphoma cells. To further confirm the role of SNHG4 in translation regulation, a plasmid, which contains a renilla luciferase driven by SV40 promoter, was co-transfected with SNHG4 siRNA into Mino cells. The luciferase signal, decreased compared with the cells transfected with nontargeting siRNA. These data suggest that SNHG4 is involved in the regulation of protein translation. In order to clarify the mechanism of lncRNAs bound to eIF4E we searched for RNA binding sites or motifs in eIF4E protein using the web-based tools, BindN and PPRInt. Interestingly two RNA binding motifs, KNKRGGRWLITLNKQQRRS and SHADTATKSGSTTKNR, were found in eIF4E based on the prediction. To examine whether lncRNAs bind with eIF4E through these RNA binding motifs, an eIF4E mutant plasmid with both RNA binding motifs deleted (eIF4EDel), was constructed and transfected transiently into HEK-293T cells along with eIF4EWT plasmid. RNA-IP data showed that the lncRNAs SNHG12, SNHG4 and SNHG1 were not able to bind with eIF4E in eIF4EDel-transfected cells compared with that of eIF4EWT, suggesting that these lncRNAs complex with eIF4E through RNA-binding motifs within the eIF4E. Overall, our results show that the lncRNAs, SNHG1 and SNHG4 are able to bind with eIF4E and regulate protein translation. Since lncRNAs had been found to play roles in the regulation of gene expression, including transcription, splicing and mRNA stability, our results may broaden the view of the functional role of lncRNAs in translation in lymphoma cells and in other cancers. Furthermore, our results also suggested that SNHG4 lncRNAs might be served as potential biomarkers for MCL and other B cell lymphomas for translation therapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Targeting Transcription Checkpoint Using a Novel CDK9 Inhibitor in Mantle Cell Lymphoma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 28-29
Author(s):  
Junwei Lian ◽  
Yu Xue ◽  
Alexa A Jordan ◽  
Joseph McIntosh ◽  
Yang Liu ◽  
...  
Keyword(s):  
B Cell ◽  
Mantle Cell Lymphoma ◽  
Mouse Models ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Research Funding ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Mantle Cell ◽  
Cdk9 Inhibitor

Introduction Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma that accounts for 5-8% of all non-Hodgkin lymphomas. Despite the Bruton's tyrosine kinase inhibitor ibrutinib and the BH3 mimetic BCL2 inhibitor venetoclax (ABT-199) have proven to be effective therapeutic strategies for MCL, most patients often experience disease progression after treatment. Thus, developing a novel drug to overcome this aggressive relapsed/refractory malignancy is an urgent need. Cyclin-dependent kinase 9 (CDK9) is a serine/threonine kinase belonging to the CDK family which regulates multiple cellular processes, particularly in driving and maintaining cancer cell growth. Unlike classical CDKs, CDK9 is a critical component of the positive transcription elongation factor b (P-TEFb) complex that mediates transcription elongation and mRNA maturation via phosphorylating RNA polymerase II (RNAP2). Previous studies demonstrated that CDK9 inhibition downregulates transcription levels of MCL-1 and MYC, which are crucial in both survival and proliferation of acute myeloid leukemia and diffuse large B-cell lymphoma. We and others found that the MYC signaling pathway was enhanced in MCL, especially in ibrutinib-resistant MCL patients. MYC is a core transcription factor driving lymphomagenesis. It does not possess enzymatic activity and has long been considered to be undruggable. MCL-1 is a key anti-apoptotic protein and is overexpressed in several hematologic malignancies. It was also found to be overexpressed in ibrutinib or venetoclax-resistant MCL cells. Thus, CDK9 is considered as a potential target that may inhibit MYC and MCL-1 pathways. Although recently it was shown that MC180295, a novel selective inhibitor of CDK9, has nanomolar levels anti-cancer potency, whether its beneficial effects extend to relapsed/refractory MCL has not yet been assessed. Methods We use three paired MCL cells sensitive/resistant to ibrutinib or venetoclax to test the efficacy of CDK9 inhibitor MC180295. Cell viability was measured by using Cell Titer Glo (Promega). Cell apoptosis assay and western blot analyses were used to identify affected pathways after MC180295 treatment. Finally, we used patient-derived xenograft (PDX) mouse models to test the therapeutic potential of MC180295 in MCL. Results First, we examined the potential efficacy of a CDK9 inhibitor MC180295 in MCL cells. MC180295 treatment results in growth inhibition of ibrutinib-resistant or venetoclax-resistant MCL cells. By assessing the caspase 3 and PARP activity, we found that MC180295 treatment induces cell death via cell apoptosis in MCL cell lines. Meanwhile, we found that RNAP2 phosphorylation at Ser2, the active form of RNAP2, is downregulated in MC180295 treated MCL cell lines. Consistent to previous studies, MC180295 treatment significantly reduces the protein level of MYC and MCL-1. In addition, we identified several other important proteins, such as cyclin D1 and BCL-XL, were also downregulated upon MCL180295 treatment. MC180295 was able to overcome ibrutinib-venetoclax dual resistance in PDX mouse models without severe side effects. To improve the efficacy of MC180295 as a single agent, we performed in vitro combinational drug screen with a number of FDA-approved or investigational clinical agents and found that MC180295 had a synergistic effect with venetoclax. We are currently investigating the underlying mechanism of action. Conclusion Taken together, our findings showed that targeting CDK9 by its specific inhibitor MC180295 is effective in targeting MCL cells, especially those with ibrutinib or venetoclax resistance and therefore supports the concept that CDK9 is a new target to overcome ibrutinib/venetoclax resistance in MCL. Disclosures Wang: MoreHealth: Consultancy; Dava Oncology: Honoraria; Beijing Medical Award Foundation: Honoraria; OncLive: Honoraria; Molecular Templates: Research Funding; Verastem: Research Funding; Guidepoint Global: Consultancy; Nobel Insights: Consultancy; Oncternal: Consultancy, Research Funding; InnoCare: Consultancy; Loxo Oncology: Consultancy, Research Funding; Targeted Oncology: Honoraria; OMI: Honoraria, Other: Travel, accommodation, expenses; Celgene: Consultancy, Other: Travel, accommodation, expenses, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Lu Daopei Medical Group: Honoraria; Pulse Biosciences: Consultancy; Kite Pharma: Consultancy, Other: Travel, accommodation, expenses, Research Funding; Juno: Consultancy, Research Funding; BioInvent: Research Funding; VelosBio: Research Funding; Acerta Pharma: Research Funding.

scholarly journals Targeting Glutamine Metabolism Overcomes Resistance to Targeted Therapies in Refractory Mantle Cell Lymphoma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 25-26
Author(s):  
Lingzhi Li ◽  
Changying Jiang ◽  
Lucy Jayne Navsaria ◽  
Yang Liu ◽  
Angela Leeming ◽  
...  
Keyword(s):  
Cell Viability ◽  
B Cell ◽  
Cell Lines ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Tca Cycle ◽  
Glutamine Metabolism ◽  
Metabolomic Profiling ◽  
The Tca Cycle ◽  
Mantle Cell

Background: Mantle cell lymphoma (MCL) is an incurable B cell non-Hodgkin's lymphoma characterized by high refractory occurrence following drug treatment. Despite the encouraging initial MCL tumor response to ibrutinib (IBN), relapse occurs only after few months of treatment due to multiple resistance mechanisms. Thus, the novel therapeutic strategies targeting resistant mechanisms are crucial. Our group has recently shown that among the highly proliferative MCL population, a subpopulation of IBN-R cells exhibits increased OXPHOS activity that is fueled by increased glutaminolysis and rely more on mitochondrial respiration for their grow and survival. The aim of this work was to uncover potential targets responsible for the upregulation of OXPHOS pathway in the refractory/relapsed (R/R) MCL by using multiple biochemical and biological strategies. We focused the present study on glutaminase (GLS), the enzyme that converts glutamine to glutamate, a precursor of α-ketoglutarate (α-KG) that links glutamate to the TCA cycle. Incorporation of α-KG into the TCA cycle is a major anaplerotic step in proliferating cells and is critical for the maintenance of TCA cycle function. To further demonstrate the reliance of OXPHOS on glutamine anaplerosis, we have further tested the combinatory effects of targeting GLS and OXPHOS using their respective inhibitors, CB-839 and IACS-010759, on tumor killing activity in R/R MCL. Methods:Primary MCL cells from patient leukapheresis or whole blood specimens, as well as established MCL cell lines were used as experimental models of MCL. Metabolomic profiling was used to determine intracellular metabolite fluxes and levels. Cell Titer Glo assay was used to measure cell proliferation/viability after treatment with inhibitors. Annexin V and propidium iodide were used to measure cell apoptosis and cell cycle arrestviaflow cytometry analysis. Magnetic microbeads-based B-cell isolation method were used for the purification of malignant B cells from patient samples. Western blot analysis was used to evaluate protein level expression. Patient-derived Xenograft (PDX) mouse model created from patients with MCL was used to evaluate the in vivo anti-tumor activity and potential clinical value of GLS and OXPHOS inhibitors. Results:Our recent metabolomic profiling studies have demonstrated that glutaminolysis and OXPHOS are upregulated in IBN-R MCL, manifested by increased glutamine uptake in the ibrutinib-resistant MCL cell lines (p=0.03).Inhibition of glutamine metabolism with the allosteric GLS1-selective inhibitor BPTES resulted in inhibition of cell viability (0.2381uM-9.98uM), indicating that MCL cells are dependent on glutamine metabolism for their proliferation. To corroborate with the above finding, we also presented evidence that GLS1 is highly increased in IBN-R and CART-R MCL patient samples and cell lines confirmed by immunoblotting. Inhibiting of GLS would lead to significant reduction in OXPHOS, mitochondria membrane potential and ATP production, as either single drug or in combination with other targeting agents. To identify a clinical actionable GLS inhibitor for the treatment of MCL, we chose a GLS1 specific inhibitor CB-839 (Selleckchem), currently under several phase II and III clinical trials investigation on solid tumors. Inhibiting GLS1 with CB-839 leads to the decreased cell viability in MCL (0.5626nM-308.4nM). Of note, the treatment with CB-839 to MCL cell lines induces S phase reduction in both Jeko-1 (17.23%) and Z-138 (14.01%), as well as induces significant apoptosis (p=0.013 and p=0.002 in Jeko-1 and Z-138 cells). GLS inhibition will be further explored in the context of mitochondria defect or hypoxia, where OXPHOS maybe deficient. Importantly, while CB-839 is continuing its validation in several solid tumor models, this is the first study providing data on its efficacy in preclinical models of MCL. Conclusion:In conclusion, we report that glutaminolysis and OXPHOS are upregulated in IBN-R MCL that could be partially due to high expression of GLS1. Our preliminary results revealed that the new GLS inhibitor, GCB-839, may present a clinical potential for a new indication and warrants more in-depth investigation. Deciphering the mechanisms involved in MCL metabolic heterogeneity and adaptability during drug resistance development would be crucial to identify key actors enabling MCL cells to escape from therapy. Disclosures Wang: Acerta Pharma:Research Funding;Molecular Templates:Research Funding;InnoCare:Consultancy;Oncternal:Consultancy, Research Funding;Celgene:Consultancy, Other: Travel, accommodation, expenses, Research Funding;Targeted Oncology:Honoraria;MoreHealth:Consultancy;Kite Pharma:Consultancy, Other: Travel, accommodation, expenses, Research Funding;Lu Daopei Medical Group:Honoraria;OMI:Honoraria, Other: Travel, accommodation, expenses;Verastem:Research Funding;Nobel Insights:Consultancy;BioInvent:Research Funding;Guidepoint Global:Consultancy;AstraZeneca:Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding;Pharmacyclics:Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding;Janssen:Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding;Juno:Consultancy, Research Funding;Dava Oncology:Honoraria;Loxo Oncology:Consultancy, Research Funding;Pulse Biosciences:Consultancy;OncLive:Honoraria;Beijing Medical Award Foundation:Honoraria;VelosBio:Research Funding.

scholarly journals Activation of MYC, a bona fide client of HSP90, contributes to intrinsic ibrutinib resistance in mantle cell lymphoma

2018 ◽  
Vol 2 (16) ◽  
pp. 2039-2051 ◽  
Author(s):  
Jimmy Lee ◽  
Liang Leo Zhang ◽  
Wenjun Wu ◽  
Hui Guo ◽  
Yan Li ◽  
...  
Keyword(s):  
Mantle Cell Lymphoma ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
Resistant Cell ◽  
Intrinsic Resistance ◽  
Mantle Cell ◽  
Myc Gene ◽  
Bona Fide ◽  
Ibrutinib Resistance ◽  
Induced Apoptosis

Abstract The BTK inhibitor ibrutinib has demonstrated a remarkable therapeutic effect in mantle cell lymphoma (MCL). However, approximately one-third of patients do not respond to the drug initially. To identify the mechanisms underlying primary ibrutinib resistance in MCL, we analyzed the transcriptome changes in ibrutinib-sensitive and ibrutinib-resistant cell lines on ibrutinib treatment. We found that MYC gene signature was suppressed by ibrutinib in sensitive but not resistant cell lines. We demonstrated that MYC gene was structurally abnormal and MYC protein was overexpressed in MCL cells. Further, MYC knockdown with RNA interference inhibited cell growth in ibrutinib-sensitive as well as ibrutinib-resistant cells. We explored the possibility of inhibiting MYC through HSP90 inhibition. The chaperon protein is overexpressed in both cell lines and primary MCL cells from the patients. We demonstrated that MYC is a bona fide client of HSP90 in the context of MCL by both immunoprecipitation and chemical precipitation. Furthermore, inhibition of HSP90 using PU-H71 induced apoptosis and caused cell cycle arrest. PU-H71 also demonstrates strong and relatively specific inhibition of the MYC transcriptional program compared with other oncogenic pathways. In a MCL patient-derived xenograft model, the HSP90 inhibitor retards tumor growth and prolongs survival. Last, we showed that PU-H71 induced apoptosis and downregulated MYC protein in MCL cells derived from patients who were clinically resistant to ibrutinib. In conclusion, MYC activity underlies intrinsic resistance to ibrutinib in MCL. As a client protein of HSP90, MYC can be inhibited via PU-H71 to overcome primary ibrutinib resistance.

scholarly journals CD200 and Chronic Lymphocytic Leukemia: Biological and Clinical Relevance

2020 ◽  
Vol 10 ◽  
Author(s):  
Giovanni D’Arena ◽  
Vincenzo De Feo ◽  
Giuseppe Pietrantuono ◽  
Elisa Seneca ◽  
Giovanna Mansueto ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
T Lymphocytes ◽  
B Cell ◽  
Cell Lymphoma ◽  
Prognostic Significance ◽  
Cell Types ◽  
Lymphocytic Leukemia ◽  
Mantle Cell ◽  
Type Ia

CD200, a transmembrane type Ia glycoprotein belonging to the immunoglobulin protein superfamily, is broadly expressed on a wide variety of cell types, such as B lymphocytes, a subset of T lymphocytes, dendritic cells, endothelial and neuronal cells. It delivers immunosuppressive signals through its receptor CD200R, which is expressed on monocytes/myeloid cells and T lymphocytes. Moreover, interaction of CD200 with CD200R has also been reported to play a role in the regulation of tumor immunity. Overexpression of CD200 has been reported in chronic lymphocytic leukemia (CLL) and hairy cell leukemia but not in mantle cell lymphoma, thus helping to better discriminate between these different B cell malignancies with different prognosis. In this review, we focus on the role of CD200 expression in the differential diagnosis of mature B-cell neoplasms and on the prognostic significance of CD200 expression in CLL, where conflicting results have been published so far. Of interest, increasing evidences indicate that anti-CD200 treatment might be therapeutically beneficial for treating CD200-expressing malignancies, such as CLL.

A microRNA Cluster as a Target of Genomic Amplification in B-Cell Lymphomas.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3011-3011
Author(s):  
Hiroyuki Tagawa ◽  
Kennosuke Karbe ◽  
Koichi Ohshima ◽  
Yasuo Morishima ◽  
Shigeo Nakamura ◽  
...  
Keyword(s):  
T Cell ◽  
B Cell ◽  
Cell Lines ◽  
Northern Blot ◽  
Cell Lymphoma ◽  
Lymphoma Cell ◽  
Genomic Amplification ◽  
T Cell Lymphomas ◽  
Mantle Cell ◽  
Microrna Cluster

Abstract Background: Genomic gain/amplification of 13q31-q32 is frequently observed in malignant lymphomas. C13orf25, recently established as a candidate gene in malignant lymphoma via 13q31-q32 genomic amplification, encodes two variant transcripts by alternative splicing (Ota et al, Cancer Res 2004). Seven microRNA genes (miR-17-5p, miR-17-3p, miR-18, miR-19a, miR-19b, miR-20 and miR-92) are clustered in C13orf25 transcript variant 2 (C13orf25 v2). Because microRNAs display dynamic temporal and spatial expression patterns, disruption of these microRNAs may be associated with tumorigenesis. Purpose: The purposes of this study are i) to reveal frequencies of the 13q gain/amplification in various lymphoma types, and ii) to examine the expression of C13orf25 v2 and seven microRNAs using various lymphoma cell lines and tumors with and without 13q gain/amplification. Experimental Design: We analyzed genomic alterations of chromosome 13 for 12 malignant lymphoma cell lines (eight B-cell and four T-cell lymphomas), and 214 cases of B-cell lymphomas (136 cases of diffuse large B-cell lymphoma (DLBCL), 27 cases of sporadic Burkitt’s lymphoma (sBL), 29 of mantle cell lymphoma (MCL), 22 of follicular lymphoma (FCL)) and 20 cases of T-cell lymphoma by using array-based comparative genomic hybridization. The expression levels of seven microRNAs using 12 lymphoma cell lines with (four) and without (eight) 13q gain/amplification were examined by Northern-blot and quantitative real-time PCR (RQ-PCR) analyses. RQ-PCR for C13orf25 v2 (microRNA cluster) was also conducted for 21 cases of DLBCL (eight cases with 13q gain/13 cases without), 10 cases of sBL (four cases with 13q gain/amp/six cases without) and 10 cases of mantle cell lymphoma. Results: Frequent (> 20%) gain/amplification of 13q were detected in DLBCL (31 cases, 23%) and Burkitt’s lymphoma (8 cases, 30%) but no gain/amplification at 13q was found in MCL, FCL and T-cell lymphomas. Genomic amplification of 13q31-q32 was observed in four cases of DLBCL and two cases of sBL, four of which were c-MYC rearranged (two cases of DLBCL and two cases of sBL). RQ-PCR and Northern blot analyses revealed that five of the seven mature microRNAs displayed overexpression in lymphoma cell lines with 13q31 genomic gain/amplification but not in those without. RQ-PCR analysis for 21 cases of DLBCL demonstrated that the cases with 13q gain/amplification (8 cases) showed significantly higher expression of C13orf25 v2 than those without (13 cases) (Mann Whitney U test, P < 0.05). Significant higher levels of the five microRNAs in sBL with 13q gain/amplification were also confirmed by Northern blot analysis. Lower expression levels of the microRNAs were found in T cell lymphoma cell lines and tumors. Conclusion: These results suggest that the microRNA cluster (C13orf25 v2) is a target of 13q/13q31 genomic gain/amplification in DLBCL and sBL.

Combination Anti-CD74 (Milatuzumab) and CD20 (Rituximab) Monoclonal Antibody Therapy Has in Vitro and in Vivo Activity in Mantle Cell Lymphoma

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 886-886 ◽  
Author(s):  
Lapo Alinari ◽  
Erin Hertlein ◽  
David M. Goldenberg ◽  
Rosa Lapalombella ◽  
Fengting Yan ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Cell ◽  
Mantle Cell Lymphoma ◽  
Cell Lines ◽  
Combination Treatment ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Preclinical Model ◽  
Mantle Cell

Abstract Mantle cell lymphoma (MCL) is an incurable B-cell malignancy and patients with this disease have limited therapeutic options. Despite the success of Rituximab in treatment of B-cell malignancies, its use as a single agent or in combination with chemotherapy in MCL has demonstrated modest activity; thus, novel strategies are needed. CD74 is an integral membrane protein expressed on malignant B cells and implicated in promoting survival and growth, making it an attractive therapeutic target. The humanized anti-CD74 monoclonal antibody (mAb), Milatuzumab, (Immunomedics) has shown promising preclinical activity against several human B-cell lymphoma cell lines, but has not been studied in MCL. Since Rituximab and Milatuzumab target distinct antigens lacking known association, we explored a combination strategy with these mAbs in MCL cell lines, patient samples, and in a preclinical model of MCL. Flow cytometric analysis shows that the MCL cell lines Mino and JeKo, and MCL patient tumor cells, express abundant surface CD74 compared to the CD74-negative cell line, Jurkat. Incubation of Mino and JeKo cells with immobilized (goat anti-human IgG) Milatuzumab (5 μg/ml) resulted in mitochondrial depolarization and significant induction of apoptosis determined by Annexin V/PI and flow cytometry (apoptosis at 8hr=38.3±0.85% and 25.4±2.6%; 24hr=73.6±3.47% and 36±3.57%; 48hr=84.9±3.91% and 50.4±4.17%, respectively, compared to Trastuzumab (control). Expression of surviving cells from anti-CD74-treated MCL cells consistently demonstrated marked induction of surface CD74 (MFI 762) compared to control (MFI 6.1). Incubation with immobilized Rituximab (10 μg/ml) resulted in 39.5±2.5% and 37.1±8.35% apoptotic events at 8hr, 58.8±3.14%, 41.2±8.27% at 24hr, and 40.1±1.3% and 45.6±3.25% at 48hr, respectively. Combination treatment of Mino and JeKo cells with Milatuzumab and Rituximab led to significant enhancement in cell death, with 77.6±3.95% and 79.6±2.62% apoptosis at 8hr in Jeko and Mino cells (P=0.0008 and P=0.00004 vs. Milatuzumab alone; P=0.00015 and P=0.001 vs. Rituximab alone); 90.4±3.53% and 76.6±4.3% at 24hr, respectively (P=0.0042 and P=0.0002 vs. Milatuzumab, P=0.0003 and P=0.0027 vs. Rituximab alone); 92.8±0.77% and 85.6±2.62% at 48hr, respectively (P= 0.026 and P=0.0002 vs. Milatuzumab alone, P=0.0000005 and P=0.00008 compared to Rituximab alone, respectively). To examine the in vivo activity of Rituximab and Milatuzumab, a preclinical model of human MCL using the SCID (cb17 scid/scid) mouse depleted of NK cells with TMβ1 mAb (anti-murine IL2Rb) was used. In this model, intravenous injection of 40×106 JeKo cells results in disseminated MCL 3–4 weeks after engraftment. The primary end-point was survival, defined as the time to develop cachexia/wasting syndrome or hind limb paralysis. Mice were treated starting at day 17 postengraftment with intraperitoneal Trastuzumab mAb control (300 μg qod), Milatuzumab (300 μg qod), Rituximab (300 μg qod), or a combination of Milatuzumab and Rituximab. The mean survival for the combination-treated group was 55 days (95%CI:41, upper limit not reached as study was terminated at day 70), compared to 33 days for Trastuzumab-treated mice (95% CI:31,34), 35.5 days for the Milatuzumab-treated mice (95% CI:33,37), and 45 days for the Rituximab-treated mice (95%CI:30,46). The combination treatment prolonged survival of this group compared to Trastuzumab control (P=0.001), Milatuzumab (P=0.0006) and Rituximab (P=0.098). No overt toxicity from Milatuzumab or the combination regimen was noted. A confirmatory study with a larger group of mice and detailed mechanistic studies are now underway. These preliminary results provide justification for further evaluation of Milatuzumab and Rituximab in combination in MCL.

The Role of Mir-150 as a Tumor Suppressor In Malignant Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 465-465
Author(s):  
Atsushi Watanabe, ◽  
Hiroyuki Tagawa ◽  
Kazuaki Teshima ◽  
Yoshihiro Kameoka ◽  
Naoto Takahashi ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Suppressor ◽  
Cell Lines ◽  
Nk Cell ◽  
Cell Lymphoma ◽  
Telomerase Activity ◽  
Akt Signaling ◽  
T Cell Lymphoma ◽  
Nk T Cell

Abstract Abstract 465 Disease specific genetic alteration or translocation have not been identified in NK/T cell lymphoma. We recently demonstrated that over expressions of miR-21 and/or miR-155 are frequently occurring in natural killer (NK) cell lymphoma/leukemia and deeply associated with their lymphomagenesis by deregulation of AKT signaling. In this study, we tried to identify tumor suppressor miRNA(s) in malignant lymphomas including B-cell, NK-cell and CD4+T-cell lymphoma, by using quantitative PCR and/or Northern blot analysis. We found that miR-150 in both cell lines and primary samples of NK and T-cell lymphoma showed significantly lower expression than those of normal natural killer cells and CD4+T cells. To examine the role for lymphomagenesis, we stably transduced miR-150 into lymphoma cell lines. Enforced expression of miR-150 in NK/T cell lymphoma cell lines showed increased levels of susceptibility of apoptosis, and showed senescence with reduced levels of telomerase activity and telomere DNA shortening. We further demonstrated that miR-150 directly down regulate AKT2, leading to reduced expression of phosphorylated AKTser473/474 with upregulation of tumor suppressors, Bim, p27 and p53. Since it has been proven that AKT kinase phosphorylate hTERT (human telomerase reverse transcript), downregulation of miR-150 in lymphomas lead to activate telomerase activity, resulting immortalization of the cancer cells. These results suggest that miR-150 play as a role of tumor suppressor in NK/T-cell lymphoma. Our recent and previous report demonstrate that downregulation of miR-150 and upregulation of miR-21/miR-155 collaborately contribute to NK/T-cell lymphomagenesis by deregulating AKT signaling. These findings will give a new insight into the pathogenesis of NK/T cell lymphoma and the miR-150 itself and/or AKT targeting therapy can be a useful against aggressive lymphoma. Disclosures: No relevant conflicts of interest to declare.

Microrna-16 Regulates BMI1 in the Clonogenic Side Population of Refractory Mantle Cell Lymphoma

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 861-861
Author(s):  
Kazuaki Teshima ◽  
Miho Nara ◽  
Atsushi Watanabe ◽  
Mitsugu Ito ◽  
Yoshiaki Hatana ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cell Lines ◽  
Target Gene ◽  
Cell Lymphoma ◽  
Side Population ◽  
Upstream Regulator ◽  
Bmi1 Expression ◽  
Mantle Cell

Abstract Abstract 861 Background: Mantle cell lymphoma (MCL) is categorized as an indolent CD5+ B-cell lymphoma and is associated with numerous genomic copy number alterations, including 9p21 deletion (CDKN2A) and 10p12 amplification (BMI1). The target gene of the 10p12 amplification has been identified as BMI1, whose overexpression is frequently observed in the blastoid variant of MCL. CDKN2A is also well-known target of BMI1 in solid tumor. So, it has been hypothesized that BMI1 regulates CDKN2A in MCL. However there are the MCL cases with both 10p12 amplification and 9p21 homozygous deletion, suggesting that BMI1 might regulate the other target gene(s). The proto-oncogene, BMI1 is crucially involved in cancer stem cell maintenance and the upregulation has been demonstrated in aggressive or relapsed cases of solid tumors. Cancer stem cells are often identified in the side population (SP) of cancer cells, which is detected based on the cell's ability to export Hoechst 33342 dye via an ATP-binding cassette (ABC) membrane transporter, which gives the SP a distinct low-staining pattern. Aim of the study: The aim of this study is to determine the role of BMI1 in MCL initiating cells, especially in the relapsed cases. In this presentation, we show that the SP fraction has stem cell-like characteristics and high tumorigenic potential, and that BMI1 expression is upregulated in the SP in both relapsed MCL cases and MCL cell lines. Further we show that miR-16 is upstream regulator of the BMI1 in MCL. Results: To determine the role of BMI1 in the pathogenesis of MCL-initiating cells, we firstly examined BMI1 expression at primary MCL cases and found that its expression is stronger in cases of recurrent MCL than at initial diagnosis. We next characterized the MCL SP and found that the SP cells exhibit cancer stem cell-like features and upregulated BMI1 expression, which appears to enhance anti-apoptosis activity. Knocking down of BMI1 increases apoptosis and reduces tumorigenicity in CDKN2A−/− MCL cell lines (REC1 and Z138c). Subcutaneous inoculation of NOD/Shi-scid IL-2γnul (NOG) mice with CDKN2A−/− MCL cell lines, siBMI1-expressing cells were significantly smaller than those in mice receiving control siRNA in vivo. Chip assay showed that BMI1 interacts with BCL2L11/Bim and PMAIP3/Noxa, which were recently shown to be Bmi-1 target. These results suggest that BMI1/Bmi-1 may regulate Bim and/or Noxa to inhibit apoptosis in MCL cells. Furthermore, upon screening for upstream regulator of BMI1, we found that expression of a non-cording regulatory RNA, microRNA-16 (miR-16) is weaker in MCL SP cells than in non-SP cells. To investigate relationship between BMI1 and miR-16, we transfected miR-16 into MCL cell lines, and found that it directly downregulated BMI1, leading to reductions in tumor size following in vivo lymphoma xenograft (NOG mice). Finally, we find that bortezomib, which is known to be a proteasome inhibitor, led to dose-and time- dependent reductions in Bmi-1 expression with re-upregulation of miR-16 in both cell lines and a primary sample. Conclusion: We conclude that dysregulation of miR-16 and BMI1 plays a key role in lymphomagenesis by reducing MCL cell apoptosis, especially in refractory/recurrent cases via enhancement of anti apoptotic function. Disclosures: No relevant conflicts of interest to declare.

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