...B18: B-cell lymphoma patient-derived xenograft...

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Abstract B18: B-cell lymphoma patient-derived xenograft models: The road to personalized therapy | Request PDFHomeHematologic NeoplasmsHematologic DiseasesLymphomaNon-Hodgkin LymphomaMedicineHematologyFollicular LymphomaArticleAbstract B18: B-cell lymphoma patient-derived xenograft models: The road to personalized therapyAugust 2016Clinical Cancer Research 22(16 Supplement):B18-B18DOI:10.1158/1557-3265.PDX16-B18Authors: Zhang LeoNYSTU Lan V PhamUniversity of Texas MD Anderson Cancer Center Hui ZhangHui ZhangThis person is not on ResearchGate, or hasn t claimed this research yet. Jingmeng XieJingmeng XieThis person is not on ResearchGate, or hasn t claimed this research yet.Show all 10 authorsHide Request full-text PDFTo read the full-text of this research, you can request a copy directly from the authors.Request full-textDownload citation Copy link Link copied Request full-text Download citation Copy link Link copiedTo read the full-text of this research, you can request a copy directly from the authors.AbstractLymphoma is the most common hematological malignancy, and B-cell lymphoma accounts for 85% of all lymphomas. The current overall cure rate for B-cell lymphoma is estimated at ~30%, even with the development and application of novel therapies, and the majority of patients relapse after treatment due to the development of drug resistance. The evaluation of novel drug targets using established B-cell lymphoma cell lines is limited by the inexact correlation between responsiveness observed in the cell line versus the patient sample. However, patient-derived xenograft (PDX) mouse models have been shown to recapitulate the diversity of growth, metastasis, and histopathology of the original tumor, overcoming the limitations of cell lines. Furthermore, recent studies have indicated that PDXs can recapitulate treatment responses of the parental tumor and can successfully choose a therapeutic target and regimen for the patient. We previously established a SCID-hu in vivo human primary mantle cell lymphoma (MCL) PDX model, the first human primary MCL animal model for biological and therapeutic research, and investigated the disease biology and potential novel human MCL therapies using this model. In this MCL PDX model, the engraftment and growth of patient MCL cells were dependent on the human bone marrow microenvironment supplied by an implanted human fetal bone chip. Our clinical information and reports show that numerous B-cell lymphoma subtypes involve bone marrow; therefore, we expanded our PDX model to include various B-cell lymphomas to study the clonal evolution of tumors and to evaluate novel therapies for the treatments of these diseases. PDX models (n=20) were established for multiple different types of B-cell lymphoma, including MCL (n=12), Burkitt s lymphoma (n=1), marginal zone lymphoma (n=2), follicular lymphoma (n=2), chronic lymphocytic leukemia (n=1) and diffuse large B-cell lymphoma (n=2). The engraftment rate was high at 95%, the tumor xenografts rapidly grew at 3-4 weeks/generation, and 68% of the tumor xenografts were passaged for multiple generations, even up to 14 generations. Further demonstrating the utility of this model to recapitulate the characteristics of the original patient tumor, the tumor xenograft cells migrated to the lymph nodes, spleen, bone marrow, and gastrointestinal tract of the host mice, mimicking the disease progression observed in humans, and H E staining showed similar histological features between the original patient tumor and the tumor xenograft cells such as splenomegaly. To identify novel targeted treatments for these various lymphomas, we assessed the in vitro cell viability of MCL, DLBCL, and Burkitt s lymphoma cells from the patients and isolated from the PDXs of different generations. The responses to these agents were very similar between the PDXs and the original patient tumor, and the treatment responses were the same between different generations, showing that the PDX models recapitulate the drug response of the original tumor. Finally, in 34% of relapsed/refractory MCL patients who were treated with ibrutinib, transient lymphocytosis was observed, and this phenomenon was also observed in our MCL PDX mouse models treated with ibrutinib. Furthermore, the combination of ibrutinib and rituximab quenched lymphocytosis in the animal model, which provided the basis of using this combination in a clinical trial in which the MCL patients had an overall response rate of 88%. In conclusion, these data demonstrate the ability of PDX mouse models to successfully recapitulate and the characteristics of the original patient tumor as well as mimic the progression of the disease in vivo. In addition, the drug responses of the original patient tumor to various agents were similar to the responses of the tumor xenograft, demonstrating that these PDX models can be used as a way to personalize the treatment of numerous types of B-cell lymphomas.Citation Format: Leo Zhang, Lan Pham, Hui Zhang, Jingmeng Xie, Wenjing Tao, Taylor Bell, Zhihong Chen, Bingliang Fang, Michael Wang, Krystle Nomie. B-cell lymphoma patient-derived xenograft models: The road to personalized therapy. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B18. Discover the world s research20+ million members135+ million publications700k+ research projectsJoin for freeNo full-text available To read the full-text of this research, you can request a copy directly from the authors.Request full-text PDFCitations (0)References (0)ResearchGate has not been able to resolve any citations for this publication.ResearchGate has not been able to resolve any references for this publication.Recommended publicationsDiscover more about: Follicular LymphomaArticleDNA Polymerase μ Gene Expression in B-Cell Non-Hodgkin s LymphomasOctober 2002 · American Journal Of PathologyApril ChiuLangxing PanZongdong Li[...]Daniel M. KnowlesDNA polymerase μ (pol μ) is a novel error-prone DNA repair enzyme bearing significant structural homology with terminal deoxynucleotidyltransferase. Whereas other human error-prone DNA polymerases identified thus far show no preferential lymphoid tissue distribution, the highest levels of pol μ mRNA have been detected in peripheral lymphoid tissues, particularly germinal center B cells. ... [Show full abstract] Conceivably, up-regulation of the pol μ gene may be biologically significant in lymphomagenesis, especially in the development of B-cell non-Hodgkin s lymphomas (B-NHLs), because of enhanced error-prone DNA repair activities. To explore this possibility, we generated a digoxigenin-labeled riboprobe to pol μ mRNA and used the probe and in situ hybridization to examine the expression pattern of the pol μ gene in formalin-fixed, paraffin-embedded tissue sections of 37 B-NHLs. This included eight chronic lymphocytic leukemia/small lymphocytic lymphomas, six mantle cell lymphomas, seven follicular lymphomas, nine diffuse large B-cell lymphomas, three splenic marginal zone lymphomas, two Burkitt s lymphomas, and two precursor B-lymphoblastic lymphomas. We also correlated the pol μ mRNA expression levels with the tumor proliferation index, which was assessed in each case by image analysis of Ki-67 immunostained slides. Nineteen of 21 (90%) B-NHLs arising from postgerminal center B cells (follicular lymphomas, diffuse large B-cell lymphomas, splenic marginal zone lymphomas, and Burkitt s lymphomas) exhibited high expression of pol μ mRNA. In contrast, only 2 of 16 (13%) B-NHLs arising from pregerminal center B cells (chronic lymphocytic leukemia/small lymphocytic lymphomas, mantle cell lymphomas, and precursor B-lymphoblastic lymphomas) expressed significant levels of pol μ mRNA. Pol μ gene expression did not seem to correlate with the proliferation index, especially because a significant level of pol μ mRNA was not detected in either case of precursor B-lymphoblastic lymphomas. In conclusion, pol μ gene expression is highly associated with B-NHLs of postgerminal center B-cell derivation. Furthermore, the expression level is independent of the proliferation rate and thus is unrelated to the biological aggressiveness of the tumors. These findings, along with the error-prone nature of the enzyme, suggest that up-regulation of pol μ gene expression may be a contributing factor to the pathogenesis of a subset of B-NHLs through DNA repair-associated genomic instability.Read moreChapterLymphomaOctober 2013E. Edmund Kim Franklin WongThe term lymphoma identifies two distinct groups of tumors: Hodgkin’s disease (HD) and non-Hodgkin’s lymphoma (NHL). Since the late 1970s, significant progress has been made in the elucidation of the pathogenesis of NHL as a clonal malignant expansion of B or T cells. B lymphocytes are generated in the bone marrow as a result of a multistep differentiation process. On entering the germinal center ... [Show full abstract] (GC), B cells activate into centroblasts, proliferate, and mature into centrocytes. Cells that have exited the GC have two fates: differentiation into either plasma cells or into memory B cells. Based on the absence or presence of somatic immunoglobulin (Ig) hypermutation, B-cell NHL can be grouped into two broad histogenetic categories: One derived from pre-GC B cells and devoid of Ig mutations (mantle cell lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma), and the other derived from B cells that have transited through the GC and harbor Ig mutations (follicular lymphoma, lymphoplasmacytoid lymphoma, mucosa-associated lymphoid tissue lymphoma, diffuse large cell lymphoma, Burkitt’s lymphoma). The pathogenesis of lymphoma represents a multistep process involving the progressive and clonal accumulation of multiple genetic lesions affecting protooncogenes and tumor suppressor genes. The genome of lymphoma cells is relatively stable and is characterized by few nonrandom chromosomal abnormalities, commonly represented by chromosomal translocations. A new classification, called the Revised European-American Lymphoma, was created in the early 1990s to establish definitions for distinct lymphomatous diseases based on morphologic, clinical, immunophenotypic, and molecular genetic features (Table 28.1).Read moreArticleDifferential Expression of CD200 in B-Cell Neoplasms by Flow Cytometry Can Assist in Diagnosis, Subc...December 2014 · American Journal of Clinical PathologyPramoda Challagundla L. Jeffrey Medeiros Rashmi Kanagal-Shamanna[...] Jeffrey L JorgensenObjectives: To analyze CD200 expression by flow cytometry in a large series of B-cell neoplasms in a variety of tissue types in comparison with benign B-lineage cells.Methods: We measured CD200 expression levels in 505 peripheral blood (PB), bone marrow (BM), and lymphoid tissue biopsy specimens, including 364 cases positive for B-cell leukemias and lymphomas.Results: CD200 expression in ... [Show full abstract] chronic lymphocytic leukemia cases was as bright as or brighter than normal PB B cells in nearly all cases, while mantle cell lymphoma (MCL) cases were usually dim or negative. However, rare MCL cases (about 5%) were moderately bright for CD200. Marginal zone lymphomas varied by subtype, with nodal cases brighter, splenic cases dimmer, and extranodal cases heterogeneous for CD200 expression. Follicular lymphoma (FL) cells were brighter for CD200 in BM specimens than in lymph nodes. In some BM specimens, dim CD200 could distinguish FL cells from background hematogones. Large B-cell lymphomas of the non-germinal center type tended to be brighter for CD200 than those of the germinal center type, while Burkitt lymphomas were negative.Conclusions: CD200 staining by flow cytometry can be useful in the differential diagnosis of B-cell neoplasms and in their detection in the BM.Read moreArticleSignificance of Conventional Cytogenetics in Improving the Diagnosis and Prognosis of Lymphoid Neopl...December 2015 · Blood Aurelia Meloni-Ehrig Christine CurtisSean P. Mahoney[...]Lawrence HertzbergCytogenetic analysis is invaluable for the detection of chromosome abnormalities in tumor samples and is the gold standard technique (unique in providing a complete overview of the chromosome complement). Cytogenetic studies of lymph node specimens (LN) can be challenging due to progressively smaller biopsies being procured, low viability, and low proliferative rates. Typically, the initial ... [Show full abstract] laboratory evaluation of LN includes flow cytometry and/or immunohistochemistry. Due to overlapping immunophenotypic and morphologic features of some lymphomas, these studies can be insufficient to properly classify a lymphoid neoplasm. Interphase FISH is the test most frequently utilized for LN genetic evaluation. Although FISH has higher sensitivity than conventional cytogenetics, there is vast literature on the existence of cytogenetic abnormalities that are not targeted by the FISH probe(s) used in most laboratories. This is predominantly true for CLL/SLL, but it is also seen in other lymphomas, particularly those characterized by variant translocations involving closely related genes, such as mantle cell lymphoma with alternate translocations involving the CCND2 or CCND3 genes, or lymphomas carrying MYC rearrangements where the partner is not IGH (translocation partners other than Ig genes might merit less aggressive therapy). To achieve the same information obtained from an abnormal karyotype, it is usually necessary to perform multiple FISH tests with significantly increased costs. Genomic microarray and sequencing also have limitations. Microarray can only detect DNA unbalances (missing the balanced translocations that characterize most lymphomas). These whole genomic tests cannot detect multiple related clones indicative of clonal evolution, or unrelated clonal populations indicative of distinct lymphoid neoplasms in the same specimen. Successful cytogenetics offers the best visual representation of the whole chromosome complement and often yields information making it unnecessary to perform additional genetic tests. It should be noted that alternative genetic tests are extremely useful for cases with normal chromosome results or those that lack metaphase cells for analysis, as well as those with cytogenetically cryptic rearrangements or mutations. Recent studies indicate that complex karyotypes in lymphomas are, in general, indicative of transformation and/or worse prognosis. In the present study, for example, several follicular lymphoma cases displayed other abnormalities in addition to the typical t(14;18), some of which are known to be associated with transformation, i.e., deletions 1p, 6q, and 10q. We present our experience with 362 LN received over a 15 month period during 2014 and 2015. See Table below. Through correlation with all diagnostic test results from our laboratory, we demonstrate the unique value of cytogenetic evaluation of lymphoid tissues, optimizing diagnostic/prognostic assessment and, thereby, improving patient management/therapeutic decisions, while achieving cost reduction.Table. A) Summary of cases and subdivision based on successful cytogenetics and normal or abnormal flow/morphology versus normal or abnormal cytogenetics; B) Detailed information on the number of the various lymphoid neoplasms included in our study. Total Cases: 362 No metaphases: 67 (19%) With metaphases: 295 (81%) Normal flow/morphology and normal cytogenetics 74 (25%) Abnormal flow and/or morphology 221 (75%) Normal cytogenetics: 59 (27%) Abnormal Cytogenetics: 162 (73%)Table. Final Diagnosis (Abnormal cytogenetic cases) # cases Sex (M/F) # FISH FISH Abnormal/normal FL 56 25/31 43 43/0 SLL/CLL 32 20/12 21 20/1 HGL 14 7/7 0 0 TCL 14 7/7 5 3/2 MZBCL 13 8/5 8 5/3 DH/THL 10 6/4 10 10/0 DLBCL 8 4/4 8 7/1 MCL 7 4/3 5 4/1 CD30+ 2 0/2 2 1/1 NGCL 2 0/2 2 1/1 BL 1 1/0 1 1/0 LPL 1 1/0 0 0 B-ALL/LBL 1 0/1 1 1/0 HL 1 1/0 1 1/0 Totals 162 84/78 107 (66%) 97/10 Abbreviations: FL, follicular lymphoma; SLL/CLL, small lymphocytic lymphoma/chronic lymphocytic leukemia; HGL, high-grade lymphoma; TCL, T-cell lymphoma; MZBCL, marginal zone B-cell lymphoma; DH/THL, double hit/triple-hit lymphoma; DLBCL, diffuse large B-cell lymphoma; MCL, mantle cell lymphoma,; CD30+, CD30-positive large B-cell lymphoma; NGCL, non-germinal center lymphoma; BL, Burkitt lymphoma; LPL, lymphoplasmacytic lymphoma; B-ALL/LBL, B-cell acute lymphoblastic leukemia/lymphoblastic lymphoma; HL, Hodgkin lymphoma.DisclosuresNo relevant conflicts of interest to declare.Read moreArticleFull-text availableB and T lymphocyte attenuator expression in mature B cell lymphomasJune 2012 · Journal of Hematopathology Philippe Trougouboff Hila Kreizman SheferB and T lymphocyte attenuator (BTLA) is a lymphocyte inhibitory receptor mainly expressed on several subsets of T and B lymphocytes. In the current retrospective study, BTLA expression is examined for the first time on formalin fixed and paraffin embedded (FFPE) tissue sections of mature B cell non-Hodgkin s lymphomas (253 cases), using a newly developed monoclonal antibody. BTLA is highly ... [Show full abstract] expressed in chronic lymphocytic leukemia/small lymphocytic lymphoma. In contrast, BTLA expression is nearly absent in mantle cell lymphoma and is not expressed in any of the follicular lymphoma cases of all grades. In marginal zone lymphoma, diffuse large B cell lymphoma, and Burkitt s lymphoma, a minority of the cases exhibit expression of BTLA. This study demonstrates the value of BTLA expression as an additional tool in the panel of immunochemical markers used for the differential diagnosis of mature B cell lymphomas in FFPE tissue sections.View full-textArticleRole of blood and bone marrow examination in the diagnosis of mature lymphoid neoplasms in patients...March 2015 · Hematology (Amsterdam, Netherlands) Sreejesh Sreedharanunni Man Updesh Singh Sachdeva Pankaj Malhotra[...] Reena DasObjectivesMature lymphoid neoplasms presenting with ‘prominent splenomegaly without significant lymphadenopathy’ are uncommon and pose unique diagnostic challenges as compared to those associated with lymphadenopathy. Their descriptions in the literature are largely limited to a few case series. We analyzed the spectrum of these lymphomas diagnosed by peripheral blood (PB) and/or bone marrow ... [Show full abstract] (BM) examination.MethodsOver a period of 6 years, 75 patients were diagnosed with a lymphoma from PB/BM who had presented with predominant splenomegaly. Their clinical and laboratory records including PB and BM morphology; immunophenotyping using multi-parametric flow-cytometry and immunohistochemistry were reviewed. Wherever indicated, an extended panel of immunohistochemistry (IHC) was performed on BM biopsies for accurate sub-classification.Results and DiscussionThe commonest lymphomas were hairy cell leukemia (HCL) (32%) and splenic marginal zone lymphoma (SMZL) (24%). Others included diffuse large B cell lymphoma (8%), chronic lymphocytic leukemia/small lymphocytic lymphoma (8%), mantle cell lymphoma (2.7%), and follicular lymphoma (1.3%), all of which usually presents with lymphadenopathy. SMZL was the commonest lymphoma among females and those with massive splenomegaly and lymphocytosis; while HCL was commonest in patients with pancytopenia. SMZL commonly presented with lymphocytosis; however, 22% of them also presented with pancytopenia.ConclusionThe high diagnostic efficacy of PB and BM examination using flow-cytometry and immunohistochemistry in confirming and sub-classifying splenic lymphomas suggests that a thorough hematological evaluation should always precede a diagnostic splenectomy. Immunohistochemistry remains the best modality to identify sparse or intra-sinusoidal infiltration on BM biopsy and is particularly useful in patients with fibrotic marrows and pancytopenia.Read moreArticleRituximab Maintenenance Therapy in CD20+ B-Cell Non-Hodgkin-Lymphoma - Results of a Multicenter Pros...November 2006 · Blood Mathias Witzens-Harig Manfred HenselJohann W. Schmier[...] Anthony HoClinical and pharmacokinetic data suggest that the effect of rituximab could be improved by prolonged exposure to the drug. To test for this hypothesis we performed a prospective randomized trial of rituximab maintenance therapy in patients with CD20+ B-cell Non-Hodgkins-Lymphoma. After completion of standard treatment patients were randomized to either observation or maintenance therapy with ... [Show full abstract] rituximab (375 mg/m2) every 3 months for 2 years. Patients after first line therapy as well as relapse patients were included in the study. Patients with aggressive lymphoma were enrolled if they had achieved a complete response (CR) after initial treatment. Patients with aggressive lymphoma with residual tumor mass were examined with positrone emission tomography (PET) and qualified for randomization if PET showed no signs of tumor activity. Patients with indolent lymphoma qualified for the study if at least a partial response (PR) was achieved. So far 162 patients (pts) with CD20+ B-cell Non-Hodgkins-Lymphoma were enrolled in this trial. Histological subtypes included diffuse large cell lymphoma (69 pts), follicular lymphoma (41 pts), mantle cell lymphoma (18 pts), primary mediastinal lymphoma (15 pts), marginal zone lymphoma (9 pts), Burkitt’s lymphoma (3 pts), immunocytoma (2 pts), primary intestinal lymphoma (1 pt), hairy cell leukemia (1 pt), chronic lymphocytic leukemia (1 pt) and unclassified B-cell lymphoma (2 pts). No severe adverse events were observed during rituximab maintenance therapy. We conclude that rituximab maintenance therapy is feasable, safe and well tolerated in patients with CD20+ B-cell Non-Hodgkins-Lymphoma. Results including event free survival and overall survival for the observation group and for the maintenance therapy group will be presented.Read moreArticleFull-text availableQuantitative flow cytometric evaluation of CD200, CD123, CD43 and CD52 as a tool for the differentia...May 2017 · Revista Brasileira de Hematologia e HemoterapiaElissandra Machado ArlindoNatália Aydos MarcondesFlavo Beno FernandesGustavo Adolpho Moreira FaulhaberBackground: Distinction between mature B-cell neoplasms can be difficult due to overlapping of immunologic features and clinical manifestations. This study investigated whether quantifying mean fluorescence intensity of four monoclonal antibodies in a flow cytometry panel is useful for the differential diagnosis and characterization of these disorders.Methods: The expressions of CD52, CD200, ... [Show full abstract] CD123 and CD43 were analyzed in samples from 124 patients with mature B-cell neoplasms. The quantitative estimation of these antigens was assessed by mean fluorescence intensity.Results: The cases included were 78 chronic lymphocytic leukemias, three atypical chronic lymphocytic leukemias, six marginal zone lymphomas, 11 splenic marginal zone lymphomas, nine lymphoplasmacytic lymphomas, six mantle cell lymphomas, two hairy cell leukemias, two hairy cell leukemias variant, five follicular lymphomas, one Burkitt lymphoma and one diffuse large B-cell lymphoma. The mean fluorescence intensity of CD200 was higher in atypical chronic lymphocytic leukemia, chronic lymphocytic leukemia and hairy cell leukemia cases. CD123 showed higher mean fluorescence intensities in hairy cell leukemia cells. Chronic lymphocytic leukemia, atypical chronic lymphocytic leukemia and mantle cell lymphoma had higher expression of CD43 and all follicular lymphoma cases had very low mean fluorescence intensity values. CD52 expression was consistently positive among all cases.Conclusion: Quantitative evaluation of these markers can be a useful additional tool to better identify some types of mature B-cell neoplasms.View full-textArticleLymphoma Associated Chromosomal Abnormalities Can Be Easily Detected by FISH on Tissue Imprints. an...November 2004 · Blood Ismael BuñoPaola NavaAngela Alvarez-Doval[...]Javier MenarguezDetection of specific chromosomal abnormalities is essential in the diagnosis of several lympholiferative disorders. However, conventional cytogenetic studies are not frequently carried out from biopsies as it is in bone marrow (BM) specimens. On the contrary, FISH is usually performed on paraffin embedded tissue, an alternative with potential technical nuances both in its application and its ... [Show full abstract] interpretation. In our experience, FISH on tissue imprints is the ideal alternative to overcome these problems. In the present study, 46 tissue imprints and 17 BM smears from 43 patients with lymphomas were selected to investigate the presence of t(14;18)(q32;q21), t(11;14)(q13;q32), t(8;14)(q24;q32) and t(3;var)(q27;var). Representativity of the samples was assured prior to FISH by rapid May-Grümwald staining (Diff-Quick, QCA, Spain). Twenty imprints from reactive palatine tonsils and adenoids were used as negative controls. FISH was performed with specific dual-color dual-fusion FISH (D-FISH) probes for the first 3 translocations and a dual-color break-apart FISH probe for t(3;var)(q27;var) following the instructions of the probes supplier (Vysis, Inc). All except one sample (a BM smear stored at room temperature over 9 years), rendered satisfactory FISH hybridizations. In any case, all 43 patients could be successfully studied by FISH (the case referred above in which FISH failed in a first attempt was successfully analyzed using a different sample). The results supported the suspected diagnosis of follicular lymphoma in 22 patients, mantle cell lymphoma in 12 patients, large B-cell lymphoma in 5 patients, marginal zone lymphoma in 2 patients and B chronic lymphocytic leukemia in 2 patients. In one case, the observation of t(11;14) by FISH allowed to reclassify the case from follicular to mantle cell lymphoma and also to demonstrate clonal evolution by studying sequential tissue imprints stored for more than 6 years. Negative results also aided in the assignment of patients to proper diagnostic categories. FISH performed on tissue imprints and BM smears constitutes an optimal strategy for retrospective and prospective investigation of chromosomal abnormalities in lymphomas. Tissue imprints and BM smears conventionally stored at room temperature even for long periods of time can be safely used and sent by ordinary mail without special considerations for this purpose. Based on our experience we recommend to perform and routinely store tissue imprints whenever fresh tissue is available.Read moreArticleA Study of the Expression of the LMP1 Oncoprotein in Low-Grade B Cell Lymphomas and Correlation with...November 2012 · Blood Panagiotis T DiamantopoulosVasiliki Papadopoulou Katerina Polonyfi[...]Nora-Athina Viniou4833IntroductionThe Epstein-Barr virus has been implicated in the pathogenesis of certain human B-cell neoplasms, such as Burkitt s lymphoma, Hodgkin s disease and post-transplant lympho-proliferative disorders. Persistent latent EBV infection is, however, frequent and therefore its role is of interest in all types of B cell malignancies. In low-grade B cell lymphomas there are few reports for ... [Show full abstract] its potential role in higher grade transformation and its association with stereotypic BCRs in CLL. The mechanisms of EBV-associated B cell transformation are probably associated with its proteins expressed during latency; one of the most studied is the LMP1 oncoprotein, which is considered as an anti-apoptotic factor (activator of NF-êB). Recent studies, however, show evidence of coexisting apoptotic properties of LMP1. The level of oxidative stress reflects activation of caspase-mediated apoptotic pathways.Aims and methodsWe measured the levels of oxidative stress in low-grade B cell lymphoma patient samples and correlated them with the expression of the LMP1 oncoprotein in order to study apoptotic functions of LMP1. Whole blood samples from 48 patients aged 51–87 (median age 74 years, 25 males, 23 females) without treatment in the previous six months were examined (chronic lymphocytic leukemia: 27, marginal zone lymphoma: 12, mantle cell lymphoma: 4, hairy cell leukemia: 2, follicular lymphoma: 2, lymphoplasmacytic lymphoma: 1). Latent EBV infection was detected with RT-PCR for the viral BXLF1 gene. LMP1 expression was quantitated with Real-Time PCR in EBV-positive patients. The levels of oxidative stress were quantitated in the sera of all patients with the use of a peroxide measuring kit (PerOx TOS/TOC kit by Immundiagnostik) and compared between the LMP1-positive (13) and LMP1-negative (35) group of patients with the use of 2-tailed Mann-Whitney test.ResultsOf the fourty-eight (48) patients tested, nineteen (19) were EBV-positive. Thirteen (13) of the nineteen (19) EBV-positive ones expressed LMP1. Oxidative stress was found to be significantly higher in LMP1-negative vs LMP1-positive patients (372.3 vs 261.4 micromol/L, p=0.014).DiscussionThe role of LMP1 expression is under investigation in the non EBV-related low grade B cell lymphomas. In the present study we examined a potential effect of LMP1 expression on oxidative stress and found that levels of oxidative stress were lower in LMP1-positive vs LMP1-negative patients with low-grade B cell lymphomas, reflecting an anti-apoptotic function of LMP1. In accordance with this result, LMP1 has been shown to upregulate BCL-2 using the NF-êB pathway. BCL-2 is a major inhibitor of the initiation of caspase-related apoptotic pathways and BCL-2 upregulation inhibits apoptosis resulting in lower levels of oxidative stress. However, in a study of sixty-four patients with low grade B cell lymphomas, we recently showed that LMP1 expression increases the levels of the apoptotic marker survivin, confirming that LMP1 may also possess an apoptotic function, as has been shown by another recent study on cell lines. Conclusion. The lower oxidative stress in the LMP1-expressing low grade B cell lymphoma samples shows evidence of an apoptotic function of the oncoprotein in this group of diseases.DisclosuresNo relevant conflicts of interest to declare.Read moreArticlePatient-Derived Xenograft Model in B-Cell Lymphoma: A Platform for a Personalized Clinical TrialDecember 2016 · BloodHui ZhangTaylor Bell Makhdum Ahmed[...] Michael WangBackground: Imprecise correlation of treatment response in established cell line and cells obtained from patients (i.e., patient-primary) limits the preclinical investigation of novel compounds. Similarly, the xenograft models wherein human cancer cell lines are transplanted into immunocompromised mice do not represent the full spectrum of cancers. However, Patient-derived xenograft (PDX) mouse ... [Show full abstract] models have been shown to recapitulate the diversity of growth, metastasis, and histopathology of the original tumor. Based on our previously established mantle cell lymphoma (MCL) PDX model, we developed other B-cell lymphoma PDXs recapitulating tumor pathological and clinical characteristics, progression and response to therapeutic agents, this will provide an indispensable model system towards personalized treatment for B-cell lymphoma.Methods: We developed 34 PDX models with an implanted fetal bone chip for several B-cell lymphomas including marginal zone lymphoma (MZL), follicular lymphoma (FL), Burkitt s lymphoma (BL), and diffuse large B-cell lymphoma (DLBCL), and MCL. We tested the in vitro efficacy of a panel of drugs among freshly isolated tumor cells from patients and tumor cells from the PDX models. We also generated a drug-resistant MCL PDX model, compared the effect of targeted drugs on the tumor burden in the drug-resistant model and identified potential therapeutic opportunity with drug combinations. We validated combination therapy in vivoand conducted next generation sequencing (NGS) using a 1,212 gene panel (OncoPlus®) on DNA from primary patient cells.Results: We collected clinical samples from 34 patients with several types of B-cell lymphomas including MCL (n=21), DLBCL (n=3), FL (n=2), BL (n=1), and MZL (n=2). Of the 34 patients, 18 (53%) were newly diagnosed and untreated clinically, 11 (32%) patients were relapsed after treatment with 1-3 chemotherapy or targeted therapy treatments, and 5 (15%) patients were treated with one-dose therapy before sample collection. All of the tumor cells, from both the patient and PDXs, showed the same drug response pattern. Consecutive ibrutinib administration to PDX mice from PT1 during G4 induced the development of an ibrutinib-resistant tumor. The cell viability of isolated PDX tumor cells treated with ibrutinib was not significantly different between G1 and G2 nor was it different between G5 and G6 (p 0.05). In addition, histological features were consistent with patient tumor histology. Furthermore, whole exome sequencing revealed fidelity between the patient and PDX tumor cells as well as between subsequent generations of the PDX. [B1] We[Z2] engrafted a patients tumor cells into NSG-hu mice to create an MCL-bearing PDX mouse model (PT28-PDX). G2 PDX cells were isolated and treated with a panel of drugs. We found that G2 PDX cells were most sensitive to bortezomib (BTZ) (Velcade®). Growth inhibition of the G2 PDX cells was significantly higher with BTZ compared to ibrutinib (p=0.002) and cells were most sensitive to BTZ compared with other agents (p≤ 0.002). Based on this finding, the patient was treated with Velcade®, rituximab and dexamethasone and responded to treatment. However, the G3 PDX became resistant to BTZ. She was then treated with a 1 cycle of rituximab and cytarabine. Soon after, we initiated three-drug combination treatment with lenalidomide (Len), rituximab (RTX) and dexamethasone (DEX) in PDX G4. Len+RTX+DEX significantly prolonged mouse survival indicating that this could be an effective regimen for this patient after BTZ relapse. As guided by the PDX, PT28 underwent Len+RTX+DEX regimen and her peripheral lymphocytosis disappeared demonstrating response.Conclusions: The PDX model with implanted fetal bone chip is a valid experimental platform that recapitulates tumor characteristics of B-cell lymphomas. Leveraging the PDX platform to identify and select drugs that are likely to be efficacious for individual patients and subsequently administering the promising agents to those who relapse after an initial therapy is the next milestone.DisclosuresWang: BeiGene: Research Funding; Asana BioSciences: Research Funding; Juno Therapeutics: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Onyx: Research Funding; Kite Pharma: Research Funding; Acerta Pharma: Consultancy, Membership on an entity s Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity s Board of Directors or advisory committees, Research Funding.Read moreChapterLymphoma GeneticsMarch 2010PhD Assistant Professor in Medicine Anthony G Letai MD John G GribbenIntroductionTechniquesTypes of genetic abnormalityBurkitt lymphomaDiffuse large B-cell lymphomaMantle cell lymphomaFollicular lymphomaLymphoplasmacytoid lymphomaMucosa-associated lymphoid tissue lymphomaAnaplastic large cell lymphomaChronic lymphocytic leukemiaConclusionsFurther reading Read moreLooking for the full-text?You can request the full-text of this article directly from the authors on ResearchGate.Request full-textAlready a member? 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