FBXO10 deficiency and BTK activation upregulate BCL2 expression in mantle cell lymphoma.

PubMed

Li, Y; Bouchlaka, M N; Wolff, J; Grindle, K M; Lu, L; Qian, S; Zhong, X; Pflum, N; Jobin, P; Kahl, B S; Eickhoff, J C; Wuerzberger-Davis, S M; Miyamoto, S; Thomas, C J; Yang, D T; Capitini, C M; Rui, L

2016-12-01

Targeting Bruton tyrosine kinase (BTK) by ibrutinib is an effective treatment for patients with relapsed/refractory mantle cell lymphoma (MCL). However, both primary and acquired resistance to ibrutinib have developed in a significant number of these patients. A combinatory strategy targeting multiple oncogenic pathways is critical to enhance the efficacy of ibrutinib. Here, we focus on the BCL2 anti-apoptotic pathway. In a tissue microarray of 62 MCL samples, BCL2 expression positively correlated with BTK expression. Increased levels of BCL2 were shown to be due to a defect in protein degradation because of no or little expression of the E3 ubiquitin ligase FBXO10, as well as transcriptional upregulation through BTK-mediated canonical nuclear factor-κB activation. RNA-seq analysis confirmed that a set of anti-apoptotic genes (for example, BCL2, BCL-XL and DAD1) was downregulated by BTK short hairpin RNA. The downregulated genes also included those that are critical for B-cell growth and proliferation, such as BCL6, MYC, PIK3CA and BAFF-R. Targeting BCL2 by the specific inhibitor ABT-199 synergized with ibrutinib in inhibiting growth of both ibrutinib-sensitive and -resistant cancer cells in vitro and in vivo. These results suggest co-targeting of BTK and BCL2 as a new therapeutic strategy in MCL, especially for patients with primary resistance to ibrutinib.

Simultaneous Drug Targeting of the Promoter MYC G-Quadruplex and BCL2 i-Motif in Diffuse Large B-Cell Lymphoma Delays Tumor Growth.

PubMed

Kendrick, Samantha; Muranyi, Andrea; Gokhale, Vijay; Hurley, Laurence H; Rimsza, Lisa M

2017-08-10

Secondary DNA structures are uniquely poised as therapeutic targets due to their molecular switch function in turning gene expression on or off and scaffold-like properties for protein and small molecule interaction. Strategies to alter gene transcription through these structures thus far involve targeting single DNA conformations. Here we investigate the feasibility of simultaneously targeting different secondary DNA structures to modulate two key oncogenes, cellular-myelocytomatosis (MYC) and B-cell lymphoma gene-2 (BCL2), in diffuse large B-cell lymphoma (DLBCL). Cotreatment with previously identified ellipticine and pregnanol derivatives that recognize the MYC G-quadruplex and BCL2 i-motif promoter DNA structures lowered mRNA levels and subsequently enhanced sensitivity to a standard chemotherapy drug, cyclophosphamide, in DLBCL cell lines. In vivo repression of MYC and BCL2 in combination with cyclophosphamide also significantly slowed tumor growth in DLBCL xenograft mice. Our findings demonstrate concurrent targeting of different DNA secondary structures offers an effective, precise, medicine-based approach to directly impede transcription and overcome aberrant pathways in aggressive malignancies.

Loss in MCL-1 function sensitizes non-Hodgkin's lymphoma cell lines to the BCL-2-selective inhibitor venetoclax (ABT-199).

PubMed

Phillips, D C; Xiao, Y; Lam, L T; Litvinovich, E; Roberts-Rapp, L; Souers, A J; Leverson, J D

2015-11-13

As a population, non-Hodgkin's lymphoma (NHL) cell lines positive for the t(14;18) translocation and/or possessing elevated BCL2 copy number (CN; BCL2(High)) are exquisitely sensitive to navitoclax or the B-cell lymphoma protein-2 (BCL-2)-selective inhibitor venetoclax. Despite this, some BCL2(High) cell lines remain resistant to either agent. Here we show that the MCL-1-specific inhibitor A-1210477 sensitizes these cell lines to navitoclax. Chemical segregation of this synergy with the BCL-2-selective inhibitor venetoclax or BCL-XL-selective inhibitor A-1155463 indicated that MCL-1 and BCL-2 are the two key anti-apoptotic targets for sensitization. Similarly, the CDK inhibitor flavopiridol downregulated MCL-1 expression and synergized with venetoclax in BCL2(High) NHL cell lines to a similar extent as A-1210477. A-1210477 also synergized with navitoclax in the majority of BCL2(Low) NHL cell lines. However, chemical segregation with venetoclax or A-1155463 revealed that synergy was driven by BCL-XL inhibition in this population. Collectively these data emphasize that BCL2 status is predictive of venetoclax potency in NHL not only as a single agent, but also in the adjuvant setting with anti-tumorigenic agents that inhibit MCL-1 function. These studies also potentially identify a patient population (BCL2(Low)) that could benefit from BCL-XL (navitoclax)-driven combination therapy.

Loss in MCL-1 function sensitizes non-Hodgkin's lymphoma cell lines to the BCL-2-selective inhibitor venetoclax (ABT-199)

PubMed Central

Phillips, D C; Xiao, Y; Lam, L T; Litvinovich, E; Roberts-Rapp, L; Souers, A J; Leverson, J D

2015-01-01

As a population, non-Hodgkin's lymphoma (NHL) cell lines positive for the t(14;18) translocation and/or possessing elevated BCL2 copy number (CN; BCL2High) are exquisitely sensitive to navitoclax or the B-cell lymphoma protein-2 (BCL-2)-selective inhibitor venetoclax. Despite this, some BCL2High cell lines remain resistant to either agent. Here we show that the MCL-1-specific inhibitor A-1210477 sensitizes these cell lines to navitoclax. Chemical segregation of this synergy with the BCL-2-selective inhibitor venetoclax or BCL-XL-selective inhibitor A-1155463 indicated that MCL-1 and BCL-2 are the two key anti-apoptotic targets for sensitization. Similarly, the CDK inhibitor flavopiridol downregulated MCL-1 expression and synergized with venetoclax in BCL2High NHL cell lines to a similar extent as A-1210477. A-1210477 also synergized with navitoclax in the majority of BCL2Low NHL cell lines. However, chemical segregation with venetoclax or A-1155463 revealed that synergy was driven by BCL-XL inhibition in this population. Collectively these data emphasize that BCL2 status is predictive of venetoclax potency in NHL not only as a single agent, but also in the adjuvant setting with anti-tumorigenic agents that inhibit MCL-1 function. These studies also potentially identify a patient population (BCL2Low) that could benefit from BCL-XL (navitoclax)-driven combination therapy. PMID:26565405

BCL-W has a fundamental role in B cell survival and lymphomagenesis.

PubMed

Adams, Clare M; Kim, Annette S; Mitra, Ramkrishna; Choi, John K; Gong, Jerald Z; Eischen, Christine M

2017-02-01

Compromised apoptotic signaling is a prerequisite for tumorigenesis. The design of effective therapies for cancer treatment depends on a comprehensive understanding of the mechanisms that govern cell survival. The antiapoptotic proteins of the BCL-2 family are key regulators of cell survival and are frequently overexpressed in malignancies, leading to increased cancer cell survival. Unlike BCL-2 and BCL-XL, the closest antiapoptotic relative BCL-W is required for spermatogenesis, but was considered dispensable for all other cell types. Here, however, we have exposed a critical role for BCL-W in B cell survival and lymphomagenesis. Loss of Bcl-w conferred sensitivity to growth factor deprivation-induced B cell apoptosis. Moreover, Bcl-w loss profoundly delayed MYC-mediated B cell lymphoma development due to increased MYC-induced B cell apoptosis. We also determined that MYC regulates BCL-W expression through its transcriptional regulation of specific miR. BCL-W expression was highly selected for in patient samples of Burkitt lymphoma (BL), with 88.5% expressing BCL-W. BCL-W knockdown in BL cell lines induced apoptosis, and its overexpression conferred resistance to BCL-2 family-targeting BH3 mimetics. Additionally, BCL-W was overexpressed in diffuse large B cell lymphoma and correlated with decreased patient survival. Collectively, our results reveal that BCL-W profoundly contributes to B cell lymphoma, and its expression could serve as a biomarker for diagnosis and aid in the development of better targeted therapies.

BCL-W has a fundamental role in B cell survival and lymphomagenesis

PubMed Central

Adams, Clare M.; Kim, Annette S.; Mitra, Ramkrishna; Choi, John K.; Gong, Jerald Z.; Eischen, Christine M.

2017-01-01

Compromised apoptotic signaling is a prerequisite for tumorigenesis. The design of effective therapies for cancer treatment depends on a comprehensive understanding of the mechanisms that govern cell survival. The antiapoptotic proteins of the BCL-2 family are key regulators of cell survival and are frequently overexpressed in malignancies, leading to increased cancer cell survival. Unlike BCL-2 and BCL-XL, the closest antiapoptotic relative BCL-W is required for spermatogenesis, but was considered dispensable for all other cell types. Here, however, we have exposed a critical role for BCL-W in B cell survival and lymphomagenesis. Loss of Bcl-w conferred sensitivity to growth factor deprivation–induced B cell apoptosis. Moreover, Bcl-w loss profoundly delayed MYC-mediated B cell lymphoma development due to increased MYC-induced B cell apoptosis. We also determined that MYC regulates BCL-W expression through its transcriptional regulation of specific miR. BCL-W expression was highly selected for in patient samples of Burkitt lymphoma (BL), with 88.5% expressing BCL-W. BCL-W knockdown in BL cell lines induced apoptosis, and its overexpression conferred resistance to BCL-2 family–targeting BH3 mimetics. Additionally, BCL-W was overexpressed in diffuse large B cell lymphoma and correlated with decreased patient survival. Collectively, our results reveal that BCL-W profoundly contributes to B cell lymphoma, and its expression could serve as a biomarker for diagnosis and aid in the development of better targeted therapies. PMID:28094768

JCAR014 and Durvalumab in Treating Patients With Relapsed or Refractory B-cell Non-Hodgkin Lymphoma

ClinicalTrials.gov

2018-04-02

BCL2 Gene Rearrangement; BCL6 Gene Rearrangement; CD19 Positive; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; High-Grade B-Cell Lymphoma With MYC, BCL2, and BCL6 Rearrangements; MYC Gene Rearrangement; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma

Bcl-2 expression in Hodgkin's lymphoma progression.

PubMed

Flangea, Corina; Potencz, Elena; Mihăescu, Rodica; Gîju, S; Anghel, A

2008-01-01

Hodgkin's lymphoma study by immunohistochemical expression of Bcl-2 in Hodgkin and Reed-Sternberg cells can precise these cases evolutive way. Sixty-three cases of classical Hodgkin's disease, hospitalized into the Hematology Department of the County Hospital No. 1 Timisoara, were studied. Histopathological diagnostic was performed using common staining methods, and for revealing the tumoral developments immunohistochemical staining was performed Bcl-2. In our study, the results were noticed a direct relation between the rise of tumoral proliferation index expressions of Bcl-2 and progression of the disease (p < or = 0.001). For I and II stages Bcl-2 expression does not overcome (-/+) category while the III and IV stages, all the cases are situated in (+/-) and (+) categories. No connection we can be noticed between the histological type and Bcl-2 expression although the classic Hodgkin's lymphoma with lymphocyte depletion is considered the most aggressive histological type (p < or = 1). In our study, we found this correlation very important because the main cause of relapses is inadequate staging. In some cases, this staging is difficult; some little lymph nodes could be overlooked because they can be placed in less accessible areas and cannot be evidenced by the most imagistic methods. All the cases were Bcl-2 expression higher than (+/-) and are staged as I and II stages should be reinvestigated and restaged. This immunohistochemical reaction, although less used in Romania, is very accurate. That is very important because the therapeutically attitude is different in advances stages compared to earlier stages.

[Diffuse large B-cell lymphoma with concomitant c-MYC and BCL6 gene rearrangements with primary skin involvement: A case report and a review of literature].

PubMed

Gabeeva, N G; Koroleva, D A; Belyaeva, A V; Chernova, N G; Kuzmina, L A; Sudarikov, A B; Obukhova, T N; Kovrigina, A M; Zvonkov, E E; Savchenko, V G

Double-hit lymphoma (DHL) is a rare aggressive B-cell lymphoma with concomitant c-MYC, BCL2 or BCL6 gene rearrangements, which is characterized by the high frequency of extranodal lesions and by resistance to chemotherapy. The median survival does not exceed 18 months in patients with this disease. The majority of DHL is represented by с-MYC/BCL2 cases. The combination of c-MYC/BCL6 occurs rarely (5-8%). The paper describes a case of DHL with concomitant c-MYC and BCL6 gene rearrangements, which mimics diffuse large B-cell lymphoma, leg-type.

Cutaneous double-hit B-cell lymphoma: an aggressive form of B-cell lymphoma with a propensity for cutaneous dissemination.

PubMed

Magro, Cynthia M; Wang, Xuan; Subramaniyam, Shivakumar; Darras, Natasha; Mathew, Susan

2014-04-01

Diffuse large cell B-cell lymphoma of the skin is most commonly represented by diffuse large cell variants of primary cutaneous follicle center cell lymphoma and the leg-type lymphoma. In a minority of cases, the infiltrates are an expression of stage 4 disease of established extracutaneous B-cell lymphoma. We describe 3 patients with an aggressive form of B-cell lymphoma secondarily involving the skin. Two of the patients were in the ninth decade of life, whereas 1 patient was 34 years of age. In the elderly patients, there was an antecedent and/or concurrent history of follicular lymphoma, whereas in the younger patient, the tumor was a de novo presentation of this aggressive form of lymphoma. The elderly patients succumbed to their disease within less than a year from the time of diagnosis, whereas 1 patient is alive but with persistent and progressive disease despite chemotherapeutic intervention. The infiltrates in all 3 cases were diffuse and composed of large malignant hematopoietic cells that exhibited a round nucleus with a finely dispersed chromatin. Phenotypically, the tumor cells were Bcl-2 and CD10 positive, whereas Bcl-6 and Mum-1 showed variable positivity. One case showed combined Mum-1 positivity along with an acute lymphoblastic lymphoma phenotype, including the absence of CD20 expression. In each case, there was a c-MYC and BCL2/IGH rearrangement diagnostic of double-hit lymphoma. In one case, there was an additional BCL6 rearrangement, defining what is in essence triple-hit lymphoma. In conclusion, double-hit lymphoma is an aggressive form of B-cell neoplasia resistant to standard chemotherapy regimens, which in many but not all cases represents tumor progression in the setting of a lower grade B-cell malignancy.

Alisertib and Romidepsin in Treating Patients With Relapsed or Refractory B-Cell or T-Cell Lymphomas

ClinicalTrials.gov

2018-05-02

High Grade B-Cell Lymphoma With MYC and BCL2 or BCL6 Rearrangements; MYC Positive; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Mature T- and NK-Cell Non-Hodgkin Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Hodgkin Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Mature T-Cell and NK-Cell Non-Hodgkin Lymphoma

A Gammaherpesvirus Bcl-2 Ortholog Blocks B Cell Receptor-Mediated Apoptosis and Promotes the Survival of Developing B Cells In Vivo

PubMed Central

Coleman, Carrie B.; McGraw, Jennifer E.; Feldman, Emily R.; Roth, Alexa N.; Keyes, Lisa R.; Grau, Katrina R.; Cochran, Stephanie L.; Waldschmidt, Thomas J.; Liang, Chengyu; Forrest, J. Craig; Tibbetts, Scott A.

2014-01-01

Gammaherpesviruses such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV, HHV-8) establish lifelong latency in their hosts and are associated with the development of several types of malignancies, including a subset of B cell lymphomas. These viruses are thought to co-opt the process of B cell differentiation to latently infect a fraction of circulating memory B cells, resulting in the establishment of a stable latency setpoint. However, little is known about how this infected memory B cell compartment is maintained throughout the life of the host. We have previously demonstrated that immature and transitional B cells are long-term latency reservoirs for murine gammaherpesvirus 68 (MHV68), suggesting that infection of developing B cells contributes to the maintenance of lifelong latency. During hematopoiesis, immature and transitional B cells are subject to B cell receptor (BCR)-mediated negative selection, which results in the clonal deletion of autoreactive B cells. Interestingly, numerous gammaherpesviruses encode homologs of the anti-apoptotic protein Bcl-2, suggesting that virus inhibition of apoptosis could subvert clonal deletion. To test this, we quantified latency establishment in mice inoculated with MHV68 vBcl-2 mutants. vBcl-2 mutant viruses displayed a marked decrease in the frequency of immature and transitional B cells harboring viral genome, but this attenuation could be rescued by increased host Bcl-2 expression. Conversely, vBcl-2 mutant virus latency in early B cells and mature B cells, which are not targets of negative selection, was remarkably similar to wild-type virus. Finally, in vivo depletion of developing B cells during chronic infection resulted in decreased mature B cell latency, demonstrating a key role for developing B cells in the maintenance of lifelong latency. Collectively, these findings support a model in which gammaherpesvirus latency in circulating mature B cells is sustained in part through the

Clinical Significance of "Double-hit" and "Double-protein" expression in Primary Gastric B-cell Lymphomas.

PubMed

He, Miaoxia; Chen, Keting; Li, Suhong; Zhang, Shimin; Zheng, Jianming; Hu, Xiaoxia; Gao, Lei; Chen, Jie; Song, Xianmin; Zhang, Weiping; Wang, Jianmin; Yang, Jianmin

2016-01-01

Primary gastric B-cell lymphoma is the second most common malignancy of the stomach. There are many controversial issues about its diagnosis, treatment and clinical management. "Double-hit" and "double-protein" involving gene rearrangement and protein expression of c-Myc and bcl2/bcl6 are the most used terms to describe DLBCL poor prognostic factors in recent years. However, very little is known about the role of these prognostic factors in primary gastric B-cell lymphomas. This study aims to obtain a molecular pathology prognostic model of gastric B-cell lymphoma for clinical stratified management by evaluating how the "double-hit" and "double-protein" in tumor cells as well as microenvironmental reaction of tumor stromal tissue affect clinical outcome in primary gastric B-cell lymphomas. Data and tissues of 188 cases diagnosed with gastric B-cell lymphomas were used in this study. Tumor tissue microarray (TMA) of formalin fixed and paraffin embedded (FFPE) tissues was constructed for fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) analysis with a serial of biomarkers containing MYC, BCL2, BCL6, CD31, SPARC, CD10, MUM1 and Ki-67. Modeled period analysis was used to estimate 3-year and 5-year overall survival (OS) and disease-free survival (DFS) distributions. There was no definite "double-hit" case though the gene rearrangement of c-Myc (5.9%), bcl2 (0.1%) and bcl6 (7.4%) was found in gastric B-cell lymphomas. The gene amplification or copy gains of c-Myc (10.1%), bcl-2 (17.0%) and bcl-6 (0.9%) were present in these lymphomas. There were 12 cases of the lymphomas with the "double-protein" expression of MYC and BCL2/BCL6. All patients with "double-protein" gastric B-cell lymphomas had poor outcome compared with those without. More importantly, "MYC-BCL2-BCL6" negative group of gastric B-cell lymphoma patients had favorable clinical outcome regardless clinical stage, pathological types and therapeutic modalities. And the similar better

Prognostic significance of MYC, BCL2, and BCL6 rearrangements in patients with diffuse large B-cell lymphoma treated with cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab.

PubMed

Akyurek, Nalan; Uner, Aysegul; Benekli, Mustafa; Barista, Ibrahim

2012-09-01

Diffuse large B-cell lymphomas (DLBCLs) are a biologically heterogeneous group in which various gene alterations have been reported. The aim of this study was to investigate the frequency and prognostic impact of BCL2, BCL6, and MYC rearrangements in cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab (R-CHOP)-treated DLBCL cases. Tissue microarrays were constructed from 239 cases of DLBCL, and the expressions of CD10, BCL6, MUM1/IRF4, and BCL2 were evaluated by immunohistochemistry. MYC, BCL2, and BCL6 rearrangements were investigated by interphase fluorescence in situ hybridization on tissue microarrays. Survival analysis was constructed from 145 R-CHOP-treated patients. MYC, BCL2, and BCL6 rearrangements were detected in 14 (6%), 36 (15%), and 69 (29%) of 239 DLBCL patients. Double or triple rearrangements were detected in 7 (3%) of 239 DLBCL cases. Of these, 4 had BCL2 and MYC, 2 had BCL6 and MYC, and 1 had BCL2, BCL6, and MYC rearrangements. The prognosis of these cases was extremely poor, with a median survival of 9 months. MYC rearrangement was associated with significantly worse overall survival (P = .01), especially for the cases with GC phenotype (P = .009). BCL6 rearrangement also predicted significantly shorter overall survival (P = .04), especially for the non-GC phenotype (P = .03). BCL2 rearrangement had no prognostic impact on outcome. International Prognostic Index (P = .004) and MYC rearrangement (P = .009) were independent poor prognostic factors. Analysis of MYC gene rearrangement along with BCL2 and BCL6 is critical in identifying high-risk patients with poor prognosis. Copyright © 2011 American Cancer Society.

Bcl11b, a novel GATA3-interacting protein, suppresses Th1 while limiting Th2 cell differentiation.

PubMed

Fang, Difeng; Cui, Kairong; Hu, Gangqing; Gurram, Rama Krishna; Zhong, Chao; Oler, Andrew J; Yagi, Ryoji; Zhao, Ming; Sharma, Suveena; Liu, Pentao; Sun, Bing; Zhao, Keji; Zhu, Jinfang

2018-05-07

GATA-binding protein 3 (GATA3) acts as the master transcription factor for type 2 T helper (Th2) cell differentiation and function. However, it is still elusive how GATA3 function is precisely regulated in Th2 cells. Here, we show that the transcription factor B cell lymphoma 11b (Bcl11b), a previously unknown component of GATA3 transcriptional complex, is involved in GATA3-mediated gene regulation. Bcl11b binds to GATA3 through protein-protein interaction, and they colocalize at many important cis-regulatory elements in Th2 cells. The expression of type 2 cytokines, including IL-4, IL-5, and IL-13, is up-regulated in Bcl11b -deficient Th2 cells both in vitro and in vivo; such up-regulation is completely GATA3 dependent. Genome-wide analyses of Bcl11b- and GATA3-regulated genes (from RNA sequencing), cobinding patterns (from chromatin immunoprecipitation sequencing), and Bcl11b-modulated epigenetic modification and gene accessibility suggest that GATA3/Bcl11b complex is involved in limiting Th2 gene expression, as well as in inhibiting non-Th2 gene expression. Thus, Bcl11b controls both GATA3-mediated gene activation and repression in Th2 cells. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.

B-cell transcription factors Pax-5, Oct-2, BOB.1, Bcl-6, and MUM1 are useful markers for the diagnosis of nodular lymphocyte predominant Hodgkin lymphoma.

PubMed

Herbeck, Rosemarie; Teodorescu Brînzeu, D; Giubelan, Marioara; Lazăr, Elena; Dema, Alis; Ioniţă, Hortensia

2011-01-01

In some instances, the overlap in morphologic features and antigen expression between nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) and classical Hodgkin lymphoma (cHL) can cause confusion in the diagnosis. In these cases, the transcription factors (TFs) B-cell specific activator protein (BSAP)/Pax-5, octamer binding protein-2 (Oct-2), B-lymphocyte-specific co-activator BOB.1/OBF.1, Bcl-6 protein and multiple myeloma-1/interferon regulatory factor-4 (MUM1/IRF-4) may aid in clarifying the diagnosis. Twenty-two cases of NLPHL were studied for the immunohistochemical expression of Pax-5, Oct-2, BOB.1, Bcl-6 protein and MUM1/IRF-4. Our results sustain the usefulness of the selected set of TFs to diagnose and distinguish NLPHL from cHL since Pax-5, Oct-2, BOB.1 and Bcl-6 are consistently expressed by lymphocyte predominant (LP) cells and reported by others to be often unexpressed in Hodgkin and Reed-Sternberg cells. By contrast, MUM1/IRF-4 protein scored negative in the majority of LP cells, but is reported to be expressed in almost all cases of cHL. Thus, although the expression of transcription factors is very heterogeneous, their simultaneous implementation for positive and differential diagnosis may be useful.

Venetoclax Synergizes with Radiotherapy for Treatment of B-cell Lymphomas.

PubMed

O'Steen, Shyril; Green, Damian J; Gopal, Ajay K; Orozco, Johnnie J; Kenoyer, Aimee L; Lin, Yukang; Wilbur, D Scott; Hamlin, Donald K; Fisher, Darrell R; Hylarides, Mark D; Gooley, Theodore A; Waltman, Amelia; Till, Brian G; Press, Oliver W

2017-07-15

Constitutive B-cell receptor signaling leads to overexpression of the antiapoptotic BCL-2 protein and is implicated in the pathogenesis of many types of B-cell non-Hodgkin lymphoma (B-NHL). The BCL-2 small-molecule inhibitor venetoclax shows promising clinical response rates in several lymphomas, but is not curative as monotherapy. Radiotherapy is a rational candidate for combining with BCL-2 inhibition, as DNA damage caused by radiotherapy increases the activity of pro-apoptotic BCL-2 pathway proteins, and lymphomas are exquisitely sensitive to radiation. We tested B-NHL responses to venetoclax combined with either external beam radiotherapy or radioimmunotherapy (RIT), which joins the selectivity of antibody targeting with the effectiveness of irradiation. We first tested cytotoxicity of cesium-137 irradiation plus venetoclax in 14 B-NHL cell lines representing five lymphoma subtypes. Combination treatment synergistically increased cell death in 10 of 14 lines. Lack of synergy was predicted by resistance to single-agent venetoclax and high BCL-XL expression. We then assessed the efficacy of external beam radiotherapy plus venetoclax in murine xenograft models of mantle cell (MCL), germinal-center diffuse large B-cell (GCB-DLBCL), and activated B-cell (ABC-DLBCL) lymphomas. In each model, external beam radiotherapy plus venetoclax synergistically increased mouse survival time, curing up to 10%. We finally combined venetoclax treatment of MCL and ABC-DLBCL xenografts with a pretargeted RIT (PRIT) system directed against the CD20 antigen. Optimal dosing of PRIT plus venetoclax cured 100% of mice with no detectable toxicity. Venetoclax combined with radiotherapy may be a promising treatment for a wide range of lymphomas Cancer Res; 77(14); 3885-93. ©2017 AACR . ©2017 American Association for Cancer Research.

Copper-64-labeled anti-bcl-2 PNA-peptide conjugates selectively localize to bcl-2-positive tumors in mouse models of B-cell lymphoma.

PubMed

Jia, Fang; Balaji, Baghavathy S; Gallazzi, Fabio; Lewis, Michael R

2015-11-01

The bcl-2 gene is overexpressed in non-Hodgkin's lymphoma (NHL). We have reported micro-SPECT/CT imaging of Mec-1 human lymphoma xenografts in SCID mice, using [(111)In]DOTA-anti-bcl-2-PNA-Tyr(3)-octreotate. In order to reduce normal organ accumulation and improve imaging contrast, modified monomers with neutral hydrophilic (serine, TS) or negatively charged (aspartic acid, TD) residues were synthesized as substitutes for glycine at T(14) in the PNA sequence. The parent and modified PNA-peptide conjugates were labeled with (64)Cu and evaluated in biodistribution studies and high resolution PET/CT imaging of SCID mice bearing bcl-2-positive Mec-1 xenografts as well as bcl-2-negative Ramos xenografts. Mice were administered the (64)Cu-labeled conjugates for biodistribution and imaging studies. Biodistributions were obtained from 1 to 48 h post-injection. Mice were imaged from 1 to 48 h post-injection. The parent glycine conjugate and two modified conjugates all showed selective tumor uptake in Mec-1 xenografts. The liver uptake of the serine conjugate was significantly reduced compared to the two other PNA conjugates. Its kidney uptake was highest of the three at 47.1% ID/g at 1h and dropped to 20.6% ID/g at 24h. [Copper-64]DOTA-anti-bcl-2-TS-PNA-Tyr(3)-octreotate showed tumor uptake of 1.38% ID/g at 1h and 1.06% ID/g at 24h. The tumor-to-blood ratio was increased by factor of 2 from 1h to 24h. This compound detected Mec-1 tumors by micro-PET/CT as early as 1h post-injection and at time points out to 48 h. However, the negative control Ramos tumor could not be detected. These (64)Cu-labeled, amino acid-modified PNA conjugates showed selective tumor targeting in vivo, and tumor xenografts were detected by micro-PET/CT as early as 1h post-injection, suggesting that bcl-2 expression at the mRNA level can detected by PET in mouse models of NHL. Advances in knowledge and implications for patient care Down-regulating bcl-2, an anti-apoptotic proto-oncogene, is a mechanism

Biological characterization of adult MYC-translocation-positive mature B-cell lymphomas other than molecular Burkitt lymphoma.

PubMed

Aukema, Sietse M; Kreuz, Markus; Kohler, Christian W; Rosolowski, Maciej; Hasenclever, Dirk; Hummel, Michael; Küppers, Ralf; Lenze, Dido; Ott, German; Pott, Christiane; Richter, Julia; Rosenwald, Andreas; Szczepanowski, Monika; Schwaenen, Carsten; Stein, Harald; Trautmann, Heiko; Wessendorf, Swen; Trümper, Lorenz; Loeffler, Markus; Spang, Rainer; Kluin, Philip M; Klapper, Wolfram; Siebert, Reiner

2014-04-01

Chromosomal translocations affecting the MYC oncogene are the biological hallmark of Burkitt lymphomas but also occur in a subset of other mature B-cell lymphomas. If accompanied by a chromosomal break targeting the BCL2 and/or BCL6 oncogene these MYC translocation-positive (MYC(+)) lymphomas are called double-hit lymphomas, otherwise the term single-hit lymphomas is applied. In order to characterize the biological features of these MYC(+) lymphomas other than Burkitt lymphoma we explored, after exclusion of molecular Burkitt lymphoma as defined by gene expression profiling, the molecular, pathological and clinical aspects of 80 MYC-translocation-positive lymphomas (31 single-hit, 46 double-hit and 3 MYC(+)-lymphomas with unknown BCL6 status). Comparison of single-hit and double-hit lymphomas revealed no difference in MYC partner (IG/non-IG), genomic complexity, MYC expression or gene expression profile. Double-hit lymphomas more frequently showed a germinal center B-cell-like gene expression profile and had higher IGH and MYC mutation frequencies. Gene expression profiling revealed 130 differentially expressed genes between BCL6(+)/MYC(+) and BCL2(+)/MYC(+) double-hit lymphomas. BCL2(+)/MYC(+) double-hit lymphomas more frequently showed a germinal center B-like gene expression profile. Analysis of all lymphomas according to MYC partner (IG/non-IG) revealed no substantial differences. In this series of lymphomas, in which immunochemotherapy was administered in only a minority of cases, single-hit and double-hit lymphomas had a similar poor outcome in contrast to the outcome of molecular Burkitt lymphoma and lymphomas without the MYC break. Our data suggest that, after excluding molecular Burkitt lymphoma and pediatric cases, MYC(+) lymphomas are biologically quite homogeneous with single-hit and double-hit lymphomas as well as IG-MYC and non-IG-MYC(+) lymphomas sharing various molecular characteristics.

First-in-human response of BCL-2 inhibitor venetoclax in T-cell prolymphocytic leukemia.

PubMed

Boidol, Bernd; Kornauth, Christoph; van der Kouwe, Emiel; Prutsch, Nicole; Kazianka, Lukas; Gültekin, Sinan; Hoermann, Gregor; Mayerhoefer, Marius E; Hopfinger, Georg; Hauswirth, Alexander; Panny, Michael; Aretin, Marie-Bernadette; Hilgarth, Bernadette; Sperr, Wolfgang R; Valent, Peter; Simonitsch-Klupp, Ingrid; Moriggl, Richard; Merkel, Olaf; Kenner, Lukas; Jäger, Ulrich; Kubicek, Stefan; Staber, Philipp B

2017-12-07

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive T-lymphoid malignancy usually refractory to current treatment strategies and associated with short overall survival. By applying next-generation functional testing of primary patient-derived lymphoma cells using a library of 106 US Food and Drug Administration (FDA)-approved anticancer drugs or compounds currently in clinical development, we set out to identify novel effective treatments for T-PLL patients. We found that the B-cell lymphoma 2 (BCL-2) inhibitor venetoclax (ABT-199) demonstrated the strongest T-PLL-specific response when comparing individual ex vivo drug response in 86 patients with refractory hematologic malignancies. Mechanistically, responses to venetoclax correlated with protein expression of BCL-2 but not with expression of the BCL-2 family members myeloid cell leukemia 1 (MCL-1) and BCL-XL in lymphoma cells. BCL-2 expression was inversely correlated with the expression of MCL-1. Based on the ex vivo responses, venetoclax treatment was commenced in 2 late-stage refractory T-PLL patients resulting in clinical responses. Our findings demonstrate first evidence of single-agent activity of venetoclax both ex vivo and in humans, offering a novel agent in T-PLL. © 2017 by The American Society of Hematology.

Onalespib in Treating Patients With Relapsed or Refractory Anaplastic Large Cell Lymphoma, Mantle Cell Lymphoma, or Diffuse Large B-Cell Lymphoma

ClinicalTrials.gov

2018-05-23

ALK Positive; BCL6 Positive; Recurrent Anaplastic Large Cell Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mantle Cell Lymphoma; Refractory Anaplastic Large Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mantle Cell Lymphoma

Cotton Leaf Curl Multan Betasatellite DNA as a Tool to Deliver and Express the Human B-Cell Lymphoma 2 (Bcl-2) Gene in Plants.

PubMed

Kharazmi, Sara; Ataie Kachoie, Elham; Behjatnia, Seyed Ali Akbar

2016-05-01

The betasatellite DNA associated with Cotton leaf curl Multan virus (CLCuMB) contains a single complementary-sense ORF, βC1, which is a pathogenicity determinant. CLCuMB was able to replicate in plants in the presence of diverse helper geminiviruses, including Tomato leaf curl virus-Australia (TLCV-Au), Iranian isolate of Tomato yellow leaf curl virus (TYLCV-[Ab]), and Beet curly top virus (BCTV-Svr), and can be used as a plant gene delivery vector. To test the hypothesis that CLCuMB has the potential to act as an animal gene delivery vector, a specific insertion construct was produced by the introduction of a human B-cell lymphoma 2 (Bcl-2) cDNA into a mutant DNA of CLCuMB in which the βC1 was deleted (β∆C1). The recombinant βΔC1-Bcl-2 construct was successfully replicated in tomato and tobacco plants in the presence of TLCV-Au, BCTV-Svr and TYLCV-[Ab]. Real-time PCR and Western blot analyses of plants containing the replicative forms of recombinant βΔC1-Bcl-2 DNA showed that Bcl-2 gene was expressed in an acceptable level in these plants, indicating that β∆C1 can be used as a tool to deliver and express animal genes in plants. This CLCuMB-based system, having its own promoter activity, offers the possibility of production of animal recombinant proteins in plants.

Bcl-2 and BLIMP-1 expression predict worse prognosis in gastric diffuse large B cell lymphoma (DLCBL) while other markers for nodal DLBCL are not useful.

PubMed

Martin-Arruti, Maialen; Vaquero, Manuel; Díaz de Otazu, Ramón; Zabalza, Iñaki; Ballesteros, Javier; Roncador, Giovanna; García-Orad, Africa

2012-04-01

Previous studies have identified clinicopathological and immunohistochemical differences among diffuse large B cell lymphomas (DLBCL) as a function of disease location. Nevertheless, there is a continuing tendency to generalize the prognostic value of various identified markers without taking into account tumour site. Accordingly, we analysed the prognostic value of several of the immunohistochemical markers that have been proposed for nodal DLBCL in a group of patients with gastric DLBCL. Using histochemical methods, CD10, Bcl-6, Gcet1, MUM-1, Bcl-2 and BLIMP-1 expression was investigated in 43 cases of gastric DBLCL. As in nodal DLBCLs, expression of BLIMP-1, and of Bcl-2 in non-germinal centre B cell-like (non-GCB) patients, was associated with a worse prognosis. However, unlike nodal DBLCL, there was no significant association of prognosis with expression of CD10, Bcl-6, Gcet1 or MUM-1, or with categorization according to Hans or Muris algorithms. Although most markers of prognosis in nodal DLBCL are not useful indicators for gastric DLBCL, Bcl-2 or BLIMP-1 expression does correlate with worse prognosis. These data support the notion that clinicopathological features in DLBCL vary according to the disease location. © 2012 Blackwell Publishing Ltd.

Prognostic significance of B-cell lymphoma 2 expression in acute leukemia: A systematic review and meta-analysis.

PubMed

Liu, Yanfeng; He, Pengcheng; Liu, Feng; Shi, Lili; Zhu, Huachao; Cheng, Xiaoyan; Zhao, Jing; Wang, Yuan; Zhang, Mei

2014-05-01

A number of studies have provided estimates of the correlation between B-cell lymphoma 2 (Bcl-2) expression and its clinical significance in acute leukemia (AL); however, the results have been heterogeneous. In order to clarify the prognostic significance of Bcl-2 status in patients with AL, a systematic review and meta-analysis of 5 published studies including a total of 665 subjects was performed. The reported frequency of Bcl-2 expression was 0-99.00%. Bcl-2-positive patients had a higher median white blood cell count compared to Bcl-2-negative patients. Additionally, Bcl-2-negative patients had >2-fold higher odds of achieving complete remission (CR) compared to Bcl-2-positive patients. The summary hazard ratio of Bcl-2 negativity/positivity for CR was 0.62 [95% confidence interval: 0.53-0.81, P<0.001]. Although this meta-analysis was based on data abstracted from observational studies, our results may justify the use of risk-adapted therapeutic strategies for AL according to the Bcl-2 expression status.

Allergic TH2 Response Governed by B-Cell Lymphoma 6 Function in Naturally Occurring Memory Phenotype CD4+ T Cells

PubMed Central

Ogasawara, Takashi; Kohashi, Yuko; Ikari, Jun; Taniguchi, Toshibumi; Tsuruoka, Nobuhide; Watanabe-Takano, Haruko; Fujimura, Lisa; Sakamoto, Akemi; Hatano, Masahiko; Hirata, Hirokuni; Fukushima, Yasutsugu; Fukuda, Takeshi; Kurasawa, Kazuhiro; Tatsumi, Koichiro; Tokuhisa, Takeshi; Arima, Masafumi

2018-01-01

Transcriptional repressor B-cell lymphoma 6 (Bcl6) appears to regulate TH2 immune responses in allergies, but its precise role is unclear. We previously reported that Bcl6 suppressed IL-4 production in naïve CD4+ T cell-derived memory TH2 cells. To investigate Bcl6 function in allergic responses in naturally occurring memory phenotype CD4+ T (MPT) cells and their derived TH2 (MPTH2) cells, Bcl6-manipulated mice, highly conserved intron enhancer (hcIE)-deficient mice, and reporter mice for conserved noncoding sequence 2 (CNS2) 3′ distal enhancer region were used to elucidate Bcl6 function in MPT cells. The molecular mechanisms of Bcl6-mediated TH2 cytokine gene regulation were elucidated using cellular and molecular approaches. Bcl6 function in MPT cells was determined using adoptive transfer to naïve mice, which were assessed for allergic airway inflammation. Bcl6 suppressed IL-4 production in MPT and MPTH2 cells by suppressing CNS2 enhancer activity. Bcl6 downregulated Il4 expression in MPTH2 cells, but not MPT cells, by suppressing hcIE activity. The inhibitory functions of Bcl6 in MPT and MPTH2 cells attenuated allergic responses. Bcl6 is a critical regulator of IL-4 production by MPT and MPTH2 cells in TH2 immune responses related to the pathogenesis of allergies. PMID:29696026

BCL11B-Mediated Epigenetic Repression Is a Crucial Target for Histone Deacetylase Inhibitors in Cutaneous T-Cell Lymphoma.

PubMed

Fu, Wenjing; Yi, Shengguo; Qiu, Lei; Sun, Jingru; Tu, Ping; Wang, Yang

2017-07-01

The treatment options for advanced cutaneous T-cell lymphoma (CTCL) are limited because of its unclear pathogenesis. Histone deacetylase (HDAC) inhibitors (HDACis) are recently developed therapeutics approved for refractory CTCL. However, the response rate is relatively low and unpredictable. Previously, we discovered that BCL11B, a key T-cell development regulator, was aberrantly overexpressed in mycosis fungoides, the most common CTCL, as compared with benign inflammatory skin. In this study, we identified a positive correlation between BCL11B expression and sensitivity to HDACi in CTCL lines. BCL11B suppression in BCL11B-high cells induced cell apoptosis by de-repressing apoptotic pathways and showed synergistic effects with suberoylanilide hydroxamic acid (SAHA), a pan-HDACi. Next, we identified the physical interaction and shared downstream genes between BCL11B and HDAC1/2 in CTCL lines. This interaction was essential in the anti-apoptosis effect of BCL11B, and the synergism between BCL11B suppression and HDACi treatment. Further, in clinical samples from 46 mycosis fungoides patients, BCL11B showed increased but varied expression in advanced tumor stage. Analysis of four patients receiving SAHA treatment suggested a positive correlation between BCL11B expression and favorable response to SAHA treatment. In conclusion, BCL11B may serve as a therapeutic target and a useful marker for improving HDACi efficacy in advanced CTCL. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

huJCAR014 CAR-T Cells in Treating Adult Patients With Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma or Acute Lymphoblastic Leukemia

ClinicalTrials.gov

2018-05-25

Adult B Acute Lymphoblastic Leukemia; BCL2 Gene Rearrangement; BCL6 Gene Rearrangement; CD19 Positive; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; MYC Gene Rearrangement; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Adult Acute Lymphoblastic Leukemia; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Transformed Recurrent Non-Hodgkin Lymphoma

BCL2 and MYC are expressed at high levels in canine diffuse large B-cell lymphoma but are not predictive for outcome in dogs treated with CHOP chemotherapy.

PubMed

Curran, K M; Schaffer, P A; Frank, C B; Lana, S E; Hamil, L E; Burton, J H; Labadie, J; Ehrhart, E J; Avery, P R

2017-12-01

Diffuse large B-cell lymphoma (DLBCL) is the most common haematopoietic malignancy in dogs. Recently, MYC and BCL2 expression levels determined with immunohistochemistry (IHC) were found to be prognostic in people with DLBCL. We hypothesized that canine DLBCL can be similarly subdivided into prognostic subtypes based on expression of MYC and BCL2. Cases of canine DLBCL treated with CHOP chemotherapy were retrospectively collected and 43 dogs had available histologic tissue and complete clinical follow-up. Median values of percent immunoreactive versus immunonegative cells were used to determine positive or negative expression status. Completion of CHOP was significantly associated with a positive outcome. Compared with human patients, our canine DLBCL patients had high IHC expression of both MYC and BCL2, and relative expression levels of one or both markers were not associated with clinical outcome. © 2016 John Wiley & Sons Ltd.

Targeting BCL-2-like Proteins to Kill Cancer Cells.

PubMed

Cory, Suzanne; Roberts, Andrew W; Colman, Peter M; Adams, Jerry M

2016-08-01

Mutations that impair apoptosis contribute to cancer development and reduce the effectiveness of conventional anti-cancer therapies. These insights and understanding of how the B cell lymphoma (BCL)-2 protein family governs apoptosis have galvanized the search for a new class of cancer drugs that target its pro-survival members by mimicking their natural antagonists, the BCL-2 homology (BH)3-only proteins. Successful initial clinical trials of the BH3 mimetic venetoclax/ABT-199, specific for BCL-2, have led to its recent licensing for refractory chronic lymphocytic leukemia and to multiple ongoing trials for other malignancies. Moreover, preclinical studies herald the potential of emerging BH3 mimetics targeting other BCL-2 pro-survival members, particularly myeloid cell leukemia (MCL)-1, for multiple cancer types. Thus, BH3 mimetics seem destined to become powerful new weapons in the arsenal against cancer. This review sketches the discovery of the BCL-2 family and its impact on cancer development and therapy; describes how interactions of family members trigger apoptosis; outlines the development of BH3 mimetic drugs; and discusses their potential to advance cancer therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Paraffin immunoreactivity of CD10, CDw75, and Bcl-6 in follicle center cell lymphoma.

PubMed

Dunphy, C H; Polski, J M; Lance Evans, H; Gardner, L J

2001-05-01

Follicle center cell lymphoma(FCCL) has the following immunophenotype(IP): sIg+, Pan B+, CD10+/-, CD5-, CD23-/+, CD43-, CD11c-, CD25-. In addition, reactivities of a malignant lymphoma with CDw75(LN-1) and bcl-6 are considered indicators of FCCL. Bcl-6 expression is common in Grade 1 FCCL (100%) and rare in other indolent B-cell lymphomas(BCL). In contrast, bcl-2 expression is common in FCCL (80%) and in other BCL subtypes. Since no previous study has correlated paraffin immunoreactivity(PIR) of CD10, CDw75, and bcl-6 in FCCL (Grades 1-3), this is this study's purpose. Twenty-nine FCCL's were identified and reviewed (6, Grade 1; 10, Grade 2; 13, Grade 3) from the Division of Hematopathology, St. Louis University. The diagnoses were based on morphology and immunohistochemistry(IH)(21 cases) +/- the flow cytometric IP(14 cases). The paraffin blocks were stained for CD10 (Novacastra, Vector Laboratories, Burlingame, CA), CDw75 and bcl-6 (DAKO Corporation, Carpinteria, CA). Results showed that, CD10 by paraffin IH(PIH) was positive in 23 [18(strong); 3(moderate); 2(weak)] and negative in 6(3, Grade 2; 3, Grade 3). All CD10-cases were CDw75+; 4, bcl-6+. The two CD10-, bcl-6-cases were Grade 2. CDw75 was positive in 28 cases [16(strong); 11(moderate); 1(weak)] and negative in 1 (Grade 3; CD10+, bcl-2+, bcl-6+). Bcl-6 was positive in 26 [16(strong); 6(moderate); 4(weak)] and negative in 3(Grade 2's). Thus, the sensitivity of CD10, CDw75, and bcl-6 by PIH for FCCL was 79%, 97%, and 90%, respectively. Of the three stains evaluated by PIH in FCCL, CDw75 was the most sensitive, closely followed by bcl-6. CD10 was least sensitive-79%. By combining these 3 stains, the sensitivity was 100%; thus, a combined approach is recommended.

Similarities of prosurvival signals in Bcl-2-positive and Bcl-2-negative follicular lymphomas identified by reverse phase protein microarray.

PubMed

Zha, Hongbin; Raffeld, Mark; Charboneau, Lu; Pittaluga, Stefania; Kwak, Larry W; Petricoin, Emanuel; Liotta, Lance A; Jaffe, Elaine S

2004-02-01

Overexpression of Bcl-2 protein has been known to play a role in the pathogenesis of follicular lymphoma (FL). However, 10-15% of FLs are negative for Bcl-2 by immunohistochemistry, raising the possibility that another gene product(s) may provide prosurvival signal(s). We used reverse phase protein microarray to analyze lysates of follicle center cells isolated by laser capture microdissection from: Bcl-2+ FL, Bcl-2- FL and reactive follicular hyperplasia (FH) (nine cases each group). TUNEL assay confirmed similar and reduced levels of apoptosis in Bcl-2+ FL and Bcl-2- FL, indicating the likelihood of Bcl-2-independent inhibition of apoptosis. Arrays were quantitatively analyzed with antibodies to proteins involved in the apoptotic pathway. As expected, Bcl-2 levels were up to eight-fold higher in Bcl-2+ FL than in FH and Bcl-2- FL. However, there was no difference in levels of Mcl-1 and survivin among these three groups. Bcl-X(L) showed a trend for increased expression in Bcl-2- FL as compared with Bcl-2+ FL, although the differences did not reach statistical significance (P>0.1). The increase in Bcl-X(L) may provide an alternative antiapoptotic signal in FL negative for Bcl-2 protein. Interestingly, Bax expression was higher in FL (Bcl-2+ or -) than in FH (P=0.001). Notably, phospho-Akt (Ser-473) was increased in FL (Bcl-2+ or -) (P<0.03) with increased phospho-Bad (Ser-136), as compared with levels in FH. The activation of the Akt/Bad pathway provides further evidence of prosurvival signals in FL, independent of Bcl-2 alone. These data suggest that nodal FL represents a single disease with a final common biochemical pathway.

Metabolic changes associated with metformin potentiates Bcl-2 inhibitor, Venetoclax, and CDK9 inhibitor, BAY1143572 and reduces viability of lymphoma cells.

PubMed

Chukkapalli, Vineela; Gordon, Leo I; Venugopal, Parameswaran; Borgia, Jeffrey A; Karmali, Reem

2018-04-20

Metformin exerts direct anti-tumor effects by activating AMP-activated protein kinase (AMPK), a major sensor of cellular metabolism in cancer cells. This, in turn, inhibits pro-survival mTOR signaling. Metformin has also been shown to disrupt complex 1 of the mitochondrial electron transport chain. Here, we explored the lymphoma specific anti-tumor effects of metformin using Daudi (Burkitt), SUDHL-4 (germinal center diffuse large B-cell lymphoma; GC DLBCL), Jeko-1 (Mantle-cell lymphoma; MCL) and KPUM-UH1 (double hit DLBCL) cell lines. We demonstrated that metformin as a single agent, especially at high concentrations produced significant reductions in viability and proliferation only in Daudi and SUDHL-4 cell lines with associated alterations in mitochondrial oxidative and glycolytic metabolism. As bcl-2 proteins, cyclin dependent kinases (CDK) and phosphoinositol-3- kinase (PI3K) also influence mitochondrial physiology and metabolism with clear relevance to the pathogenesis of lymphoma, we investigated the potentiating effects of metformin when combined with novel agents Venetoclax (bcl-2 inhibitor), BAY-1143572 (CDK9 inhibitor) and Idelalisib (p110δ- PI3K inhibitor). Co-treating KPUM-UH1 and SUDHL-4 cells with 10 mM of metformin resulted in 1.4 fold and 8.8 fold decreases, respectively, in IC-50 values of Venetoclax. By contrast, 3-fold and 10 fold reduction in IC-50 values of BAY-1143572 in Daudi and Jeko-1 cells respectively was seen in the presence of 10 mM of metformin. No change in IC-50 value for Idelalisib was observed across cell lines. These data suggest that although metformin is not a potent single agent, targeting cancer metabolism with similar but more effective drugs in novel combination with either bcl-2 or CDK9 inhibitors warrants further exploration.

IgV(H) and bcl6 somatic mutation analysis reveals the heterogeneity of cutaneous B-cell lymphoma, and indicates the presence of undisclosed local antigens.

PubMed

Franco, Renato; Camacho, Francisca I; Fernández-Vázquez, Amalia; Algara, Patrocinio; Rodríguez-Peralto, José L; De Rosa, Gaetano; Piris, Miguel A

2004-06-01

Our understanding of the ontology of B-cell lymphomas (BCL) has been improved by the study of mutational status of IgV(H) and bcl6 genes, but only a few cases of cutaneous BCL have been examined for this status. We analyzed IgV(H) and bcl6 somatic mutations in 10 cutaneous BCL, classified as follicular (three primary and one secondary), primary marginal zone (two cases), and diffuse large BCL (three primary and one secondary). We observed a lower rate (<2%) of IgV(H) mutation in all marginal zone lymphomas, and a preferential usage of V(H)2-70 (one primary follicular and two primary diffuse large BCL). Fewer than expected replacement mutations in framework regions (FR) were observed in three primary follicular lymphomas (FLs) and in all diffuse large BCL, indicating a negative antigen selection pressure. Ongoing mutations were observed in eight of 10 cases. Only two primary FLs and two diffuse large BCL showed bcl6 somatic mutation. These data support the heterogeneous nature of the different cutaneous BCL, and specifically the distinction between cutaneous follicular and marginal zone lymphomas. The biased usage of V(H)2-70, the low rate of replacement mutation in the FR, and the presence of ongoing mutation imply that local antigens could modulate the growth of primary cutaneous BCL.

Nanoparticle-based strategy for personalized B-cell lymphoma therapy

PubMed Central

Martucci, Nicola M; Migliaccio, Nunzia; Ruggiero, Immacolata; Albano, Francesco; Calì, Gaetano; Romano, Simona; Terracciano, Monica; Rea, Ilaria; Arcari, Paolo; Lamberti, Annalisa

2016-01-01

B-cell lymphoma is associated with incomplete response to treatment, and the development of effective strategies targeting this disease remains challenging. A new personalized B-cell lymphoma therapy, based on a site-specific receptor-mediated drug delivery system, was developed in this study. Specifically, natural silica-based nanoparticles (diatomite) were modified to actively target the antiapoptotic factor B-cell lymphoma/leukemia 2 (Bcl2) with small interfering RNA (siRNA). An idiotype-specific peptide (Id-peptide) specifically recognized by the hypervariable region of surface immunoglobulin B-cell receptor was exploited as a homing device to ensure specific targeting of lymphoma cells. Specific nanoparticle uptake, driven by the Id-peptide, was evaluated by flow cytometry and confocal microscopy and was increased by approximately threefold in target cells compared with nonspecific myeloma cells and when a random control peptide was used instead of Id-peptide. The specific internalization efficiency was increased by fourfold when siRNA was also added to the modified nanoparticles. The modified diatomite particles were not cytotoxic and their effectiveness in downregulation of gene expression was explored using siRNA targeting Bcl2 and evaluated by quantitative real-time polymerase chain reaction and Western blot analyses. The resulting gene silencing observed is of significant biological importance and opens new possibilities for the personalized treatment of lymphomas. PMID:27895482

High efficacy of the BCL-2 inhibitor ABT199 (venetoclax) in BCL-2 high-expressing neuroblastoma cell lines and xenografts and rational for combination with MCL-1 inhibition

PubMed Central

Bate-Eya, Laurel T.; den Hartog, Ilona J.M.; van der Ploeg, Ida; Schild, Linda; Koster, Jan; Santo, Evan E.; Westerhout, Ellen M.; Versteeg, Rogier; Caron, Huib N.; Molenaar, Jan J.; Dolman, M. Emmy M.

2016-01-01

The anti-apoptotic protein B cell lymphoma/leukaemia 2 (BCL-2) is highly expressed in neuroblastoma and plays an important role in oncogenesis. In this study, the selective BCL-2 inhibitor ABT199 was tested in a panel of neuroblastoma cell lines with diverse expression levels of BCL-2 and other BCL-2 family proteins. ABT199 caused apoptosis more potently in neuroblastoma cell lines expressing high BCL-2 and BIM/BCL-2 complex levels than low expressing cell lines. Effects on cell viability correlated with effects on BIM displacement from BCL-2 and cytochrome c release from the mitochondria. ABT199 treatment of mice with neuroblastoma tumors expressing high BCL-2 levels only resulted in growth inhibition, despite maximum BIM displacement from BCL-2 and the induction of a strong apoptotic response. We showed that neuroblastoma cells might survive ABT199 treatment due to its acute upregulation of the anti-apoptotic BCL-2 family protein myeloid cell leukaemia sequence 1 (MCL-1) and BIM sequestration by MCL-1. In vitro inhibition of MCL-1 sensitized neuroblastoma cell lines to ABT199, confirming the pivotal role of MCL-1 in ABT199 resistance. Our findings suggest that neuroblastoma patients with high BCL-2 and BIM/BCL-2 complex levels might benefit from combination treatment with ABT199 and compounds that inhibit MCL-1 expression. PMID:27056887

The expression of bcl-2 and bcl-6 protein in normal and malignant transitional epithelium.

PubMed

Lin, Zhenhua; Kim, Hankyeom; Park, Hongseok; Kim, Youngsik; Cheon, Jun; Kim, Insun

2003-08-01

The bcl-2 proto-oncogene plays a key role in cell longevity by preventing apoptosis. Bcl-2 is important in developing and maintaining the normal function of lymphoid and epithelial tissues. The bcl-6 protein is a 96 kDa nuclear protein selectively expressed in mature B cells within normal germinal centers as well as in their transformed counterparts in diffuse large B cell lymphoma. Recently, the bcl-6 protein has also been reported to be expressed in normal skin and epidermal neoplasms. In this study, 47 cases of transitional cell carcinomas (TCCs) were immunohistochemically studied for bcl-2 and bcl-6 protein expression. The results showed that bcl-2 was expressed only on basal layer cells, whereas bcl-6 expression was restricted to the superficial layers in the normal transitional epithelium. Von Brunn's nests showed strong immunostaining to bcl-2, but were negative to bcl-6. Among 47 TCCs, 15 (32.6%) and 29 (61.7%) cases were positive for bcl-2 and bcl-6, respectively. Compared with the normal transitional epithelium, the expression of bcl-2 was significantly decreased, whereas bcl-6 expression was significantly increased in TCCs. Additionally, the strong expression of bcl-6 had a positive correlation with the histopathologic grade of TCC. In conclusion, bcl-2 and bcl-6 proteins may play a role in the pathogenesis of TCCs, and bcl-6 expression reflects histopathologic grade.

Combination of Ibrutinib and ABT-199 in Diffuse Large B-Cell Lymphoma and Follicular Lymphoma.

PubMed

Kuo, Hsu-Ping; Ezell, Scott A; Schweighofer, Karl J; Cheung, Leo W K; Hsieh, Sidney; Apatira, Mutiah; Sirisawad, Mint; Eckert, Karl; Hsu, Ssucheng J; Chen, Chun-Te; Beaupre, Darrin M; Versele, Matthias; Chang, Betty Y

2017-07-01

Diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma are the most prevalent B-lymphocyte neoplasms in which abnormal activation of the Bruton tyrosine kinase (BTK)-mediated B-cell receptor signaling pathway contributes to pathogenesis. Ibrutinib is an oral covalent BTK inhibitor that has shown some efficacy in both indications. To improve ibrutinib efficacy through combination therapy, we first investigated differential gene expression in parental and ibrutinib-resistant cell lines to better understand the mechanisms of resistance. Ibrutinib-resistant TMD8 cells had higher BCL2 gene expression and increased sensitivity to ABT-199, a BCL-2 inhibitor. Consistently, clinical samples from ABC-DLBCL patients who experienced poorer response to ibrutinib had higher BCL2 gene expression. We further demonstrated synergistic growth suppression by ibrutinib and ABT-199 in multiple ABC-DLBCL, GCB-DLBCL, and follicular lymphoma cell lines. The combination of both drugs also reduced colony formation, increased apoptosis, and inhibited tumor growth in a TMD8 xenograft model. A synergistic combination effect was also found in ibrutinib-resistant cells generated by either genetic mutation or drug treatment. Together, these findings suggest a potential clinical benefit from ibrutinib and ABT-199 combination therapy. Mol Cancer Ther; 16(7); 1246-56. ©2017 AACR . ©2017 American Association for Cancer Research.

BCL10 aberations and NF-kappa B activation involving p65 are absent or rare in primary gastric MALT lymphoma.

PubMed

Hajder, Jelena; Marisavljević, Dragomir; Stanisavljević, Natasa; Mihaljević, Biljana; Kovcin, Vladimir; Marković, Olivera; Zivković, Radmila

2014-11-01

Mucosa-associated lymphoid tissue (MALT) lymphoma accounts for 5-17% non-Hodgkin lymphomas (NHL). The molecular pathogenesis of MALT lymphomas is not well-established. The aim of this study was to evaluate immunohistochemically determined nuclear coexpression of BCL10 and NF-kappaB (NF-kappaB) in tumor cells of gastric MALT lymphoma and its impact on the patogenesis and outcome of the disease. Medical records of 35 patients with newly diagnosed gastric MALT lymphoma were analyzed and biopsy specimens were immunostained for BCL10 and NF-kappaB expression (p65 subunit). The median age of 35 patients diagnosed with gastric MALT lymphoma was 63.5 years (male/female = 21/14). Symptoms were present in 23/35 (65.7%) patients with the weight loss as the most common symptom. Gastric MALT lymphomas were usually localized in the stomach corpus and corpus and antrum (45.7% and 31.2%, respectively). H. pylon infection was confirmed in 20 out of 30 (66.7%) patients. Treatment options were as follows: immunochemotherapy in 10 (28.5%) patients, surgery in 9 (25.8%) patients, combined surgery and chemotherapy in 14 (40%) patients and supportive measures in 2 (5.7%) patients. Complete remission was achieved in 13 (37.10/) patients and partial remission in two (5.7%/) patients. Sixteen (45.7%/) patients had disease progression (p < 0.001). Cytoplasmatic expression of BCL10 in tumor cells was detected in 19 (54.3%) specimens. Nuclear expression was detected in no specimen. Cytoplasmic expression of NF-kappaB was present in 22 (65.7%) specimens, but nuclear expression was not detected in any specimens. Nuclear expressions (activation)of NF-kappaB p65 subunit and BCL10 were not detected in specimens of gastric MALT lymphoma. The correlation of nuclear coexpression of BCL10 and NF-kappaB in gastric MALT lymphoma was not established. These results indicate that other mechanisms and signal pathways are active in lymphogenesis of gastric MALT lymphoma, as that apoptotic inhibition is not

Regulation of the plasma cell transcription factor Blimp-1 gene by Bach2 and Bcl6.

PubMed

Ochiai, Kyoko; Muto, Akihiko; Tanaka, Hiromu; Takahashi, Shinichiro; Igarashi, Kazuhiko

2008-03-01

B lymphocyte-induced maturation protein 1 (Blimp-1) is a key regulator for plasma cell differentiation. Prior to the terminal differentiation into plasma cells, Blimp-1 expression is suppressed in B cells by transcription repressors BTB and CNC homology 2 (Bach2) and B cell lymphoma 6 (Bcl6). Bach2 binds to the Maf recognition element (MARE) of the promoter upstream region of the Blimp-1 gene (Prdm1) by forming a heterodimer with MafK. Bach2 and Bcl6 were found to interact with each other in B cells. While both Bach2 and Bcl6 possess the BTB domain which mediates protein-protein interactions, they interacted in a BTB-independent manner. Bcl6 is known to repress Prdm1 through a Bcl6 recognition element 1 in the intron 5, in which a putative, evolutionarily conserved MARE was identified. Both repressed the expression of a reporter gene containing the intron 5 region depending on the presence of the respective binding sites in 18-81 pre-B cells. Co-expression of Bach2 and Bcl6 resulted in further repression of the reporter plasmid. Chromatin immunoprecipitation assays showed MafK to bind to the intron MARE in various B cell lines, thus suggesting that it binds as a heterodimer with Bach2. Therefore, the interaction between Bach2 and Bcl6 might be crucial for the proper repression of Prdm1 in B cells.

Double-hit lymphoma demonstrating t(6;14;18)(p25;q32;q21), suggesting two independent dual-hit translocations, MYC/BCL-2 and IRF4/BCL-2.

PubMed

Tabata, Rie; Yasumizu, Ryoji; Tabata, Chiharu; Kojima, Masaru

2013-01-01

Here, we report a rare case of double-hit lymphoma, demonstrating t(6;14;18)(p25;q32;q21), suggesting two independent dual-translocations, c-MYC/BCL-2 and IRF4/BCL-2. The present case had a rare abnormal chromosome, t(6;14;18)(p25;q32;q21), independently, in addition to known dual-hit chromosomal abnormalities, t(14;18)(q32;q21) and t(8;22)(q24;q11.2). Lymph node was characterized by a follicular and diffuse growth pattern with variously sized neoplastic follicles. The intrafollicular area was composed of centrocytes with a few centroblasts and the interfollicular area was occupied by uniformly spread medium- to large-sized lymphocytes. CD23 immunostaining demonstrated a disrupted follicular dendritic cell meshwork. The intrafollicular tumor cells had a germinal center phenotype with the expression of surface IgM, CD10, Bcl-2, Bcl-6, and MUM1/IRF4. However, the interfollicular larger cells showed plasmacytic differentiation with diminished CD20, Bcl-2, Bcl-6, and positive intracytoplasmic IgM, and co-expression of MUM1/IRF4 and CD138 with increased Ki-67-positive cells (> 90%). MUM1/IRF4 has been found to induce c-MYC expression, and in turn, MYC transactivates MUM1/IRF4, creating a positive autoregulatory feedback loop. On the other hand, MUM1/IRF4 functions as a tumor suppressor in c-MYC-induced B-cell leukemia. The present rare case arouses interest in view of the possible "dual" activation of both c-MYC and MUM1/IRF4 through two independent dual-translocations, c-MYC/BCL-2 and IRF4/BCL-2.

Anti-apoptotic BCL-2 family proteins in acute neural injury

PubMed Central

Anilkumar, Ujval; Prehn, Jochen H. M.

2014-01-01

Cells under stress activate cell survival and cell death signaling pathways. Cell death signaling frequently converges on mitochondria, a process that is controlled by the activities of pro- and anti-apoptotic B-cell lymphoma 2 (BCL-2) proteins. In this review, we summarize current knowledge on the control of neuronal survival, development and injury by anti-apoptotic BCL-2 family proteins. We discuss overlapping and differential effects of the individual family members BCL-2, BCL-extra long (BCL-XL), myeloid cell leukemia 1 (MCL-1), and BCL2-like 2 (BCL-W) in the control of survival during development and pathophysiological processes such as trophic factor withdrawal, ischemic injury, excitotoxicity, oxidative stress and energy stress. Finally we discuss recent evidence that several anti-apoptotic BCL-2 proteins influence mitochondrial bioenergetics and control neuronal Ca2+ homeostasis independent of their classical role in cell death signaling. PMID:25324720

Anti-apoptotic BCL-2 family proteins in acute neural injury.

PubMed

Anilkumar, Ujval; Prehn, Jochen H M

2014-01-01

Cells under stress activate cell survival and cell death signaling pathways. Cell death signaling frequently converges on mitochondria, a process that is controlled by the activities of pro- and anti-apoptotic B-cell lymphoma 2 (BCL-2) proteins. In this review, we summarize current knowledge on the control of neuronal survival, development and injury by anti-apoptotic BCL-2 family proteins. We discuss overlapping and differential effects of the individual family members BCL-2, BCL-extra long (BCL-XL), myeloid cell leukemia 1 (MCL-1), and BCL2-like 2 (BCL-W) in the control of survival during development and pathophysiological processes such as trophic factor withdrawal, ischemic injury, excitotoxicity, oxidative stress and energy stress. Finally we discuss recent evidence that several anti-apoptotic BCL-2 proteins influence mitochondrial bioenergetics and control neuronal Ca(2+) homeostasis independent of their classical role in cell death signaling.

Nivolumab With or Without Varlilumab in Treating Patients With Relapsed or Refractory Aggressive B-cell Lymphomas

ClinicalTrials.gov

2018-06-11

ALK-Positive Large B-Cell Lymphoma; Atypical Burkitt/Burkitt-Like Lymphoma; Burkitt-Like Lymphoma With 11q Aberration; Diffuse Large B-Cell Lymphoma Activated B-Cell Type; Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation; Diffuse Large B-Cell Lymphoma Germinal Center B-Cell Type; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; EBV-Positive Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; EBV-Positive Mucocutaneous Ulcer; High-Grade B-Cell Lymphoma With MYC, BCL2, and BCL6 Rearrangements; Human Herpesvirus 8-Positive Neoplastic Cells Present; Intravascular Large B-Cell Lymphoma; Large B-Cell Lymphoma With IRF4 Rearrangement; Plasmablastic Lymphoma; Primary Cutaneous Diffuse Large B-Cell Lymphoma; Primary Cutaneous Diffuse Large B-Cell Lymphoma, Leg Type; Primary Diffuse Large B-Cell Lymphoma of the Central Nervous System; Primary Effusion Lymphoma; Recurrent B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classic Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Lymphomatoid Granulomatosis; Recurrent Primary Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classic Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Primary Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Small Intestinal High Grade B-Cell Lymphoma, Not Otherwise Specified; T-Cell/Histiocyte-Rich Large B-Cell Lymphoma

Adult high-grade B-cell lymphoma with Burkitt lymphoma signature: genomic features and potential therapeutic targets.

PubMed

Bouska, Alyssa; Bi, Chengfeng; Lone, Waseem; Zhang, Weiwei; Kedwaii, Ambreen; Heavican, Tayla; Lachel, Cynthia M; Yu, Jiayu; Ferro, Roberto; Eldorghamy, Nanees; Greiner, Timothy C; Vose, Julie; Weisenburger, Dennis D; Gascoyne, Randy D; Rosenwald, Andreas; Ott, German; Campo, Elias; Rimsza, Lisa M; Jaffe, Elaine S; Braziel, Rita M; Siebert, Reiner; Miles, Rodney R; Dave, Sandeep; Reddy, Anupama; Delabie, Jan; Staudt, Louis M; Song, Joo Y; McKeithan, Timothy W; Fu, Kai; Green, Michael; Chan, Wing C; Iqbal, Javeed

2017-10-19

The adult high-grade B-cell lymphomas sharing molecular features with Burkitt lymphoma (BL) are highly aggressive lymphomas with poor clinical outcome. High-resolution structural and functional genomic analysis of adult Burkitt lymphoma (BL) and high-grade B-cell lymphoma with BL gene signature (adult-molecularly defined BL [mBL]) revealed the MYC-ARF-p53 axis as the primary deregulated pathway. Adult-mBL had either unique or more frequent genomic aberrations (del13q14, del17p, gain8q24, and gain18q21) compared with pediatric-mBL, but shared commonly mutated genes. Mutations in genes promoting the tonic B-cell receptor (BCR)→PI3K pathway ( TCF3 and ID3 ) did not differ by age, whereas effectors of chronic BCR→NF-κB signaling were associated with adult-mBL. A subset of adult-mBL had BCL2 translocation and mutation and elevated BCL2 mRNA and protein expression, but had a mutation profile similar to mBL. These double-hit lymphomas may have arisen from a tumor precursor that acquired both BCL2 and MYC translocations and/or KMT2D ( MLL2 ) mutation. Gain/amplification of MIR17HG and its paralogue loci was observed in 50% of adult-mBL. In vitro studies suggested miR-17∼92 's role in constitutive activation of BCR signaling and sensitivity to ibrutinib. Overall integrative analysis identified an interrelated gene network affected by copy number and mutation, leading to disruption of the p53 pathway and the BCR→PI3K or NF-κB activation, which can be further exploited in vivo by small-molecule inhibitors for effective therapy in adult-mBL.

Strategic Therapeutic Targeting to Overcome Venetoclax Resistance in Aggressive B-cell Lymphomas.

PubMed

Pham, Lan V; Huang, Shengjian; Zhang, Hui; Zhang, Jun; Bell, Taylor; Zhou, Shouhao; Pogue, Elizabeth; Ding, Zhiyong; Lam, Laura; Westin, Jason; Davis, R Eric; Young, Ken H; Medeiros, L Jeffrey; Ford, Richard J; Nomie, Krystle; Zhang, Leo; Wang, Michael

2018-04-17

Purpose: B-cell lymphoma-2 (BCL-2), an antiapoptotic protein often dysregulated in B-cell lymphomas, promotes cell survival and provides protection from stress. A recent phase I first-in-human study of the BCL-2 inhibitor venetoclax in non-Hodgkin lymphoma showed an overall response rate of 44%. These promising clinical results prompted our examination of the biological effects and mechanism of action underlying venetoclax activity in aggressive B-cell lymphoma, including mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL). Experimental Design: MCL and DLBCL cell lines, primary patient samples, and in vivo patient-derived xenograft (PDX) models were utilized to examine venetoclax efficacy. Furthermore, the mechanisms underlying venetoclax response and the development of venetoclax resistance were evaluated using proteomics analysis and Western blotting. Results: Potential biomarkers linked to venetoclax activity and targeted combination therapies that can augment venetoclax response were identified. We demonstrate that DLBCL and MCL cell lines, primary patient samples, and PDX mouse models expressing high BCL-2 levels are extremely sensitive to venetoclax treatment. Proteomics studies showed that venetoclax substantially alters the expression levels and phosphorylation status of key proteins involved in cellular processes, including the DNA damage response, cell metabolism, cell growth/survival, and apoptosis. Short- and long-term exposure to venetoclax inhibited PTEN expression, leading to enhanced AKT pathway activation and concomitant susceptibility to PI3K/AKT inhibition. Intrinsic venetoclax-resistant cells possess high AKT activation and are highly sensitive to PI3K/AKT inhibition. Conclusions: These findings demonstrate the on-target effect of venetoclax and offer potential mechanisms to overcome acquired and intrinsic venetoclax resistance through PI3K/AKT inhibition. Clin Cancer Res; 1-14. ©2018 AACR. ©2018 American Association for

Double-hit follicular lymphoma with MYC and BCL2 translocations: a study of 7 cases with a review of literature.

PubMed

Miao, Yuan; Hu, Shimin; Lu, Xinyan; Li, Shaoying; Wang, Wei; Medeiros, L Jeffrey; Lin, Pei

2016-12-01

Follicular lymphoma with MYC and BCL2 translocations, so-called double-hit follicular lymphoma (DH-FL), is rare. Here, we report the clinicopathological features of 7 cases of DH-FL. All neoplasms had a follicular pattern (1 partially diffuse). Five cases were predominantly low grade, 4 of which had focal (≤20%) grade 3A areas, and 2 cases were of grade 3. All cases were positive for pan-B-cell antigens, CD10, and BCL6; 6 cases were positive for BCL2. Ki-67 was less than or equal to 50% in 6 cases and 90% in 1 grade 3 case. Three patients presented with stage IV disease and 3 had a Follicular Lymphoma International Prognostic Index score of greater than 2. Six patients received immunochemotherapy, and 1 is still under induction therapy with rituximab, ibrutinib, and lenalidomide. Four achieved complete remission and two had a partial response with persistent or refractory disease. The median follow-up time was 25 months (range, 8.5-53.7 months). Two patients treated with standard regimen for follicular lymphoma had relapsed or refractory disease, and 1 died from complications of allogeneic stem cell transplant administered for relapse. In contrast, all 4 patients treated with more intensive regimen for double-hit lymphoma achieved complete remission. In summary, despite predominantly low-grade histology, cases of DH-FL in this study were aggressive and responded better to more intensive than standard treatment regimens, suggesting DH-FL is part of the spectrum of double-hit high-grade lymphoma. Copyright © 2016 Elsevier Inc. All rights reserved.

The selective Bcl-2 inhibitor venetoclax, a BH3 mimetic, does not dysregulate intracellular Ca2+ signaling.

PubMed

Vervloessem, Tamara; Ivanova, Hristina; Luyten, Tomas; Parys, Jan B; Bultynck, Geert

2017-06-01

Anti-apoptotic B cell-lymphoma-2 (Bcl-2) proteins are emerging as therapeutic targets in a variety of cancers for precision medicines, like the BH3-mimetic drug venetoclax (ABT-199), which antagonizes the hydrophobic cleft of Bcl-2. However, the impact of venetoclax on intracellular Ca 2+ homeostasis and dynamics in cell systems has not been characterized in detail. Here, we show that venetoclax did not affect Ca 2+ -transport systems from the endoplasmic reticulum (ER) in permeabilized cell systems. Venetoclax (1μM) did neither trigger Ca 2+ release by itself nor affect agonist-induced Ca 2+ release in a variety of intact cell models. Among the different cell types, we also studied two Bcl-2-dependent cancer cell models with a varying sensitivity towards venetoclax, namely SU-DHL-4 and OCI-LY-1, both diffuse large B-cell lymphoma cell lines. Acute application of venetoclax did also not dysregulate Ca 2+ signaling in these Bcl-2-dependent cancer cells. Moreover, venetoclax-induced cell death was independent of intracellular Ca 2+ overload, since Ca 2+ buffering using BAPTA-AM did not suppress venetoclax-induced cell death. This study therefore shows that venetoclax does not dysregulate the intracellular Ca 2+ homeostasis in a variety of cell types, which may underlie its limited toxicity in human patients. Furthermore, venetoclax-induced cell death in Bcl-2-dependent cancer cells is not mediated by intracellular Ca 2+ overload. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech. Copyright © 2016 Elsevier B.V. All rights reserved.

Involvement of p53 and Bcl-2 in sensory cell degeneration in aging rat cochleae.

PubMed

Xu, Yang; Yang, Wei Ping; Hu, Bo Hua; Yang, Shiming; Henderson, Donald

2017-06-01

p53 and Bcl-2 (B-cell lymphoma 2) are involved in the process of sensory cell degeneration in aging cochleae. To determine molecular players in age-related hair cell degeneration, this study examined the changes in p53 and Bcl-2 expression at different stages of apoptotic and necrotic death of hair cells in aging rat cochleae. Young (3-4 months) and aging (23-24 months) Fisher 344/NHsd rats were used. The thresholds of the auditory brainstem response (ABR) were measured to determine the auditory function. Immunolabeling was performed to determine the expression of p53 and Bcl-2 proteins in the sensory epithelium. Propidium iodide staining was performed to determine the morphologic changes in hair cell nuclei. Aging rats exhibited a significant elevation in ABR thresholds at all tested frequencies (p < 0.001). The p53 and Bcl-2 immunoreactivity was increased in aging hair cells showing the early signs of apoptotic changes in their nuclei. The Bcl-2 expression increase was also observed in hair cells displaying early signs of necrosis. As the hair cell degenerative process advanced, p53 and Bcl-2 immunoreactivity became reduced or absent. In the areas where no detectable nuclear staining was present, p53 and Bcl-2 immunoreactivity was absent.

E2A-positive gastric MALT lymphoma has weaker plasmacytoid infiltrates and stronger expression of the memory B-cell-associated miR-223: possible correlation with stage and treatment response.

PubMed

Liu, Ting-Yun; Chen, Shee-Uan; Kuo, Sung-Hsin; Cheng, Ann-Lii; Lin, Chung-Wu

2010-11-01

Extranodal marginal-zone lymphoma of mucosa-associated lymphoid tissue of the stomach (gastric MALT lymphoma) is derived from memory B cells of the marginal zone. Normal memory B cells do not express markers of germinal-center B cells, such as E2A (immunoglobulin enhancer-binding factor E12/E47), B-cell chronic lymphocytic leukemia/lymphoma 6 (BCL6), or activation-induced cytidine deaminase (AID). E2A is a transcription factor that induces somatic hypermutations and blocks plasma cell differentiation. In 50 stage-I(E)/II(E1) gastric MALT lymphomas, we confirmed that all cases were BCL6(-)/AID(-), but a subset (50%, 25/50) was E2A(+). As E2A(-) and E2A(+) gastric MALT lymphomas had similar numbers of somatic hypermutations without intraclonal variations, which implied an origin from memory B cells, the expression of E2A was best regarded as a marker of aberrant follicular differentiation. Although the status of somatic hypermutation was not affected by E2A, E2A(+) gastric MALT lymphoma showed less plasmacytoid infiltrates and higher expressions of miRNA-223, a microRNA associated with memory B cells. Clinically, E2A(+) gastric MALT lymphomas were more likely to spread to perigastric lymph nodes and were less responsive to Helicobacter eradication therapy than were E2A(-) gastric MALT lymphomas. Taken together, aberrant E2A expression is a diagnostic feature of a subtype of gastric MALT lymphoma with weaker plasmacytoid infiltrates and stronger miR-223 expression. A prospective study would be necessary to verify the association between E2A expression and a poor response to Helicobacter eradication therapy.

DOCK2 regulates cell proliferation through Rac and ERK activation in B cell lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lei; Nishihara, Hiroshi, E-mail: nisihara@patho2.med.hokudai.ac.jp; Kimura, Taichi

2010-04-23

DOCK2; a member of the CDM protein family, regulates cell motility and cytokine production through the activation of Rac in mammalian hematopoietic cells and plays a pivotal role in the modulation of the immune system. Here we demonstrated the alternative function of DOCK2 in hematopoietic tumor cells, especially in terms of its association with the tumor progression. Immunostaining for DOCK2 in 20 cases of human B cell lymphoma tissue specimens including diffuse large B cell lymphoma and follicular lymphoma revealed the prominent expression of DOCK2 in all of the lymphoma cells. DOCK2-knockdown (KD) of the B cell lymphoma cell lines,more » Ramos and Raji, using the lentiviral shRNA system presented decreased cell proliferation compared to the control cells. Furthermore, the tumor formation of DOCK2-KD Ramos cell in nude mice was significantly abrogated. Western blotting analysis and pull-down assay using GST-PAK-RBD kimeric protein suggested the presence of DOCK2-Rac-ERK pathway regulating the cell proliferation of these lymphoma cells. This is the first report to clarify the prominent role of DOCK2 in hematopoietic malignancy.« less

A synthetic peptide targeting the BH4 domain of Bcl-2 induces apoptosis in multiple myeloma and follicular lymphoma cells alone or in combination with agents targeting the BH3-binding pocket of Bcl-2.

PubMed

Lavik, Andrew R; Zhong, Fei; Chang, Ming-Jin; Greenberg, Edward; Choudhary, Yuvraj; Smith, Mitchell R; McColl, Karen S; Pink, John; Reu, Frederic J; Matsuyama, Shigemi; Distelhorst, Clark W

2015-09-29

Bcl-2 inhibits apoptosis by two distinct mechanisms but only one is targeted to treat Bcl-2-positive malignancies. In this mechanism, the BH1-3 domains of Bcl-2 form a hydrophobic pocket, binding and inhibiting pro-apoptotic proteins, including Bim. In the other mechanism, the BH4 domain mediates interaction of Bcl-2 with inositol 1,4, 5-trisphosphate receptors (IP3Rs), inhibiting pro-apoptotic Ca2+ signals. The current anti-Bcl-2 agents, ABT-263 (Navitoclax) and ABT-199 (Venetoclax), induce apoptosis by displacing pro-apoptotic proteins from the hydrophobic pocket, but do not inhibit Bcl-2-IP3R interaction. Therefore, to target this interaction we developed BIRD-2 (Bcl-2 IP3 Receptor Disruptor-2), a decoy peptide that binds to the BH4 domain, blocking Bcl-2-IP3R interaction and thus inducing Ca2+-mediated apoptosis in chronic lymphocytic leukemia, multiple myeloma, and follicular lymphoma cells, including cells resistant to ABT-263, ABT-199, or the Bruton's tyrosine kinase inhibitor Ibrutinib. Moreover, combining BIRD-2 with ABT-263 or ABT-199 enhances apoptosis induction compared to single agent treatment. Overall, these findings provide strong rationale for developing novel therapeutic agents that mimic the action of BIRD-2 in targeting the BH4 domain of Bcl-2 and disrupting Bcl-2-IP3R interaction.

BCL-2 and BCL-XL expression are down-regulated in benign prostate hyperplasia nodules and not affected by finasteride and/or celecoxib

PubMed Central

Li, Feng; Pascal, Laura E; Zhou, Jianhua; Zhou, Yibin; Wang, Ke; Parwani, Anil V; Dhir, Rajiv; Guo, Peng; He, Dalin; Nelson, Joel B; Wang, Zhou

2018-01-01

The mechanisms involved in the development of benign prostatic hyperplasia (BPH) are poorly understood. One potential mechanism involved in BPH pathogenesis may involve altered expression of genes related to apoptosis and proliferation because reduced cell death and increased proliferation are thought to contribute to prostatic enlargement. This study examined the expression of B-cell lymphoma 2 (BCL-2) and B-cell lymphoma-extra large (BCL-XL), two important anti-apoptosis factors that are also capable of inhibiting cell proliferation via accelerated G1 arrest or delayed G1/S transition, using immunostaining in simple prostatectomy BPH specimens from patients naïve to androgen manipulation. Since androgens and inflammation are thought to play important roles in BPH pathogenesis, we tested the effect of inhibiting 5a-reductase and/or COX-2 on the expression of BCL-2 and BCL-XL in BPH specimens from prostate cancer patients with BPH. These patients had no prior use of chronic NSAIDs and/or 5a-reductase inhibitors and were treated with celecoxib, finasteride, celecoxib plus finasteride or no treatment for 28 consecutive days prior to surgery. In all specimens, BCL-2 and BCL-XL staining was evident in both luminal and basal epithelial cells, with more intense staining in basal cells. Both luminal and basal cells exhibited decreased BCL-2 and BCL-XL staining in BPH nodules compared to the surrounding normal prostatic tissues. In prostate cancer patients with BPH, celecoxib and/or finasteride did not affect the expression of BCL-2 and BCL-XL in luminal or basal cells in BPH nodules and normal adjacent tissues. These results suggest that BCL-2 and BCL-XL may act as anti-proliferative factors in BPH pathogenesis, and the effect of celecoxib and/or finasteride on BPH is unlikely mediated through modulating BCL-2 and BCL-XL signaling. PMID:29531971

Therapeutics targeting Bcl-2 in hematological malignancies.

PubMed

Ruefli-Brasse, Astrid; Reed, John C

2017-10-23

Members of the B-cell lymphoma 2 ( BCL-2 ) gene family are attractive targets for cancer therapy as they play a key role in promoting cell survival, a long-since established hallmark of cancer. Clinical utility for selective inhibition of specific anti-apoptotic Bcl-2 family proteins has recently been realized with the Food and Drug Administration (FDA) approval of venetoclax (formerly ABT-199/GDC-0199) in relapsed chronic lymphocytic leukemia (CLL) with 17p deletion. Despite the impressive monotherapy activity in CLL, such responses have rarely been observed in other B-cell malignancies, and preclinical data suggest that combination therapies will be needed in other indications. Additional selective antagonists of Bcl-2 family members, including Bcl-X L and Mcl-1, are in various stages of preclinical and clinical development and hold the promise of extending clinical utility beyond CLL and overcoming resistance to venetoclax. In addition to direct targeting of Bcl-2 family proteins with BH3 mimetics, combination therapies that aim at down-regulating expression of anti-apoptotic BCL-2 family members or restoring expression of pro-apoptotic BH3 family proteins may provide a means to deepen responses to venetoclax and extend the utility to additional indications. Here, we review recent progress in direct and selective targeting of Bcl-2 family proteins for cancer therapy and the search for rationale combinations. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

MYC immunohistochemical and cytogenetic analysis are required for identification of clinically relevant aggressive B cell lymphoma subtypes.

PubMed

Raess, Philipp W; Moore, Stephen R; Cascio, Michael J; Dunlap, Jennifer; Fan, Guang; Gatter, Ken; Olson, Susan B; Braziel, Rita M

2018-06-01

Accurate subclassification of aggressive B cell lymphomas (ABCLs) requires integration of morphologic, immunohistochemical (IHC), and cytogenetic information. Optimal strategies have not been well defined for diagnosis of high grade B cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (HGBLwR) and double expressor lymphomas with MYC and BCL2 protein overexpression. One hundred and eighty seven ABCLs were investigated with complete IHC and FISH analysis. Morphologic and IHC analysis was insufficient to identify clinically relevant HGBLwR. Approximately, 75% of cases classified as HGBLwR showed conventional DLBCL morphologic features. Fourteen percent of MYC-rearranged cases were negative by IHC. Conversely, 60% of cases positive for MYC by IHC did not demonstrate a MYC rearrangement. Analysis by FISH without MYC and BCL2 IHC would miss 41 cases of double expressor lymphoma. Complete IHC and FISH analysis is recommended in the evaluation of all ABCLs.

Apigenin inhibits glioma cell growth through promoting microRNA-16 and suppression of BCL-2 and nuclear factor-κB/MMP‑9.

PubMed

Chen, Xin-Jun; Wu, Mian-Yun; Li, Deng-Hui; You, Jin

2016-09-01

The present study aimed to investigate the effect of apigenin on glioma cells and to explore its potential mechanism. U87 human glioma cells treated with apigenin were used in the current study. Cell Counting Kit‑8 solution and Annexin V-fluorescein isothiocyanate/propidium iodide Apoptosis Detection kit were used to analyze the effect of apigenin on U87 cell viability and apoptotic cell death. Reverse transcription‑quantitative polymerase chain reaction analysis was also used to determine microRNA‑16 (miR‑16) and MMP‑9 gene expression levels. Nuclear factor‑κB (NF‑κB) and B‑cell CLL/lymphoma 2 (BCL2) protein expression levels were determined using western blot analysis. An anti‑miR‑16 plasmid was constructed and transfected into U87 cells. The current study demonstrated that apigenin significantly decreased cell viability and induced apoptotic cell death of U87 cells in a dose‑dependent manner. Additionally, it was demonstrated that apigenin significantly increased miR‑16 levels, suppressed BCL2 protein expression and suppressed the NF‑κB/MMP9 signaling pathway in U87 cells. Furthermore, downregulation of miR‑16 using the anti‑miR‑16 plasmid reversed the effect of apigenin on cell viability, BCL2 protein expression and the NF‑κB/MMP‑9 pathway in U87 cells. The results of the present study suggested that apigenin inhibits glioma cell growth through promoting miR‑16 and suppression of BCL2 and NF-κB/MMP-9. In conclusion, the present study demonstrated the potential anticancer effects of apigenin on glioma cells.

BCL2-BH4 antagonist BDA-366 suppresses human myeloma growth.

PubMed

Deng, Jiusheng; Park, Dongkyoo; Wang, Mengchang; Nooka, Ajay; Deng, Qiaoya; Matulis, Shannon; Kaufman, Jonathan; Lonial, Sagar; Boise, Lawrence H; Galipeau, Jacques; Deng, Xingming

2016-05-10

Multiple myeloma (MM) is a heterogeneous plasma cell malignancy and remains incurable. B-cell lymphoma-2 (BCL2) protein correlates with the survival and the drug resistance of myeloma cells. BH3 mimetics have been developed to disrupt the binding between BCL2 and its pro-apoptotic BCL2 family partners for the treatment of MM, but with limited therapeutic efficacy. We recently identified a small molecule BDA-366 as a BCL2 BH4 domain antagonist, converting it from an anti-apoptotic into a pro-apoptotic molecule. In this study, we demonstrated that BDA-366 induces robust apoptosis in MM cell lines and primary MM cells by inducing BCL2 conformational change. Delivery of BDA-366 substantially suppressed the growth of human MM xenografts in NOD-scid/IL2Rγnull mice, without significant cytotoxic effects on normal hematopoietic cells or body weight. Thus, BDA-366 functions as a novel BH4-based BCL2 inhibitor and offers an entirely new tool for MM therapy.

Interaction between Na-K-ATPase and Bcl-2 proteins BclXL and Bak.

PubMed

Lauf, Peter K; Alqahtani, Tariq; Flues, Karin; Meller, Jaroslaw; Adragna, Norma C

2015-01-01

In silico analysis predicts interaction between Na-K-ATPase (NKA) and Bcl-2 protein canonical BH3- and BH1-like motifs, consistent with NKA inhibition by the benzo-phenanthridine alkaloid chelerythrine, a BH3 mimetic, in fetal human lens epithelial cells (FHLCs) (Lauf PK, Heiny J, Meller J, Lepera MA, Koikov L, Alter GM, Brown TL, Adragna NC. Cell Physiol Biochem 31: 257-276, 2013). This report establishes proof of concept: coimmunoprecipitation and immunocolocalization showed unequivocal and direct physical interaction between NKA and Bcl-2 proteins. Specifically, NKA antibodies (ABs) coimmunoprecipitated BclXL (B-cell lymphoma extra large) and BAK (Bcl-2 antagonist killer) proteins in FHLCs and A549 lung cancer cells. In contrast, both anti-Bcl-2 ABs failed to pull down NKA. Notably, the molecular mass of BAK1 proteins pulled down by NKA and BclXL ABs appeared to be some 4-kDa larger than found in input monomers. In silico analysis predicts these higher molecular mass BAK1 proteins as alternative splicing variants, encoding 42 amino acid (aa) larger proteins than the known 211-aa long canonical BAK1 protein. These BAK1 variants may constitute a pool separate from that forming mitochondrial pores by specifically interacting with NKA and BclXL proteins. We propose a NKA-Bcl-2 protein ternary complex supporting our hypothesis for a special sensor role of NKA in Bcl-2 protein control of cell survival and apoptosis. Copyright © 2015 the American Physiological Society.

Double-hit lymphomas constitute a highly aggressive subgroup in diffuse large B-cell lymphomas in the era of rituximab.

PubMed

Kobayashi, Tsutomu; Tsutsumi, Yasuhiko; Sakamoto, Natsumi; Nagoshi, Hisao; Yamamoto-Sugitani, Mio; Shimura, Yuji; Mizutani, Shinsuke; Matsumoto, Yosuke; Nishida, Kazuhiro; Horiike, Shigeo; Asano, Naoko; Nakamura, Shigeo; Kuroda, Junya; Taniwaki, Masafumi

2012-11-01

The incorporation of rituximab in immunochemotherapy has improved treatment outcomes for diffuse large B-cell lymphoma, but the prognosis for some diffuse large B-cell lymphomas remains dismal. Identification of adverse prognostic subgroups is essential for the choice of appropriate therapeutic strategy. We retrospectively investigated the impact of so-called 'double-hit' cytogenetic abnormalities, i.e. cytogenetic abnormalities involving c-MYC co-existing with other poor prognostic cytogenetic abnormalities involving BCL2, BCL6 or BACH2, on treatment outcomes for 93 consecutive diffuse large B-cell lymphoma patients. According to the revised international prognostic index, no patients were cytogenetically diagnosed with double-hit lymphomas in the 'very good' risk group or in the 'good' risk group, while 5 of 33 patients had double-hit lymphomas in the 'poor' risk group. All the double-hit lymphoma patients possessed both nodal and extranodal involvement. The overall complete response rate was 89.3%, overall survival 87.1% and progression-free survival 75.8% over 2 years (median observation period: 644 days). The complete response rates were 93.2% for the non-double-hit lymphoma patients and 40.0% for the double-hit lymphoma patients. Significantly longer progression-free survival and overall survival were observed for the 'very good' and the 'good' risk patients than for the 'poor' risk patients. Moreover, the progression-free survival of double-hit lymphoma was significantly shorter than that of the non-double-hit lymphoma 'poor' risk patients (P = 0.016). In addition, the overall survival of the double-hit lymphoma patients also tended to be shorter than that of the non-double-hit lymphoma 'poor' risk group. The diagnosis of double-hit lymphoma can help discriminate a subgroup of highly aggressive diffuse large B-cell lymphomas and indicate the need for the development of novel therapeutic strategies for double-hit lymphoma.

Targeting BCL2 With BH3 Mimetics: Basic Science and Clinical Application of Venetoclax in Chronic Lymphocytic Leukemia and Related B Cell Malignancies.

PubMed

Roberts, A W; Huang, Dcs

2017-01-01

The intracellular protein B-cell-lymphoma-2 (BCL2) has been considered an attractive target for cancer therapy since the discovery of its function as a major promoter of cell survival (an anti-apoptotic) in the late 1980s. However, the challenges of targeting a protein-protein interaction delayed the discovery of fit-for-purpose molecules until the mid-2000s. Since then, a series of high affinity small organic molecules that inhibits the interaction of BCL2 with the apoptotic machinery, the so-called BH3-mimetics, have been developed. Venetoclax (formerly ABT-199) is the first to achieve US Food and Drug Administration approval, with an indication for treatment of patients with previously treated chronic lymphocytic leukemia (CLL) bearing deletion of the long arm of chromosome 17. Here, we review key aspects of the science underpinning the clinical application of BCL2 inhibitors and explore both our current knowledge and unresolved questions about its clinical utility, both in CLL and in other B-cell malignancies that highly express BCL2. © 2016 The Authors Clinical Pharmacology & Therapeutics published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

TET2 mutations in B cells of patients affected by angioimmunoblastic T-cell lymphoma.

PubMed

Schwartz, Friederike H; Cai, Qian; Fellmann, Eva; Hartmann, Sylvia; Mäyränpää, Mikko I; Karjalainen-Lindsberg, Marja-Liisa; Sundström, Christer; Scholtysik, René; Hansmann, Martin-Leo; Küppers, Ralf

2017-06-01

Angioimmunoblastic T-cell lymphomas (AITLs) frequently carry mutations in the TET2 and IDH2 genes. TET2 mutations represent early genetic lesions as they had already been detected in haematopoietic precursor cells of AITL patients. We show by analysis of whole-tissue sections and microdissected PD1 + cells that the frequency of TET2-mutated AITL is presumably even higher than reported (12/13 cases in our collection; 92%). In two-thirds of informative AITLs (6/9), a fraction of B cells was also TET2-mutated. Investigation of four AITLs by TET2 and IGHV gene sequencing of single microdissected B cells showed that between 10% and 60% of polyclonal B cells in AITL lymph nodes harboured the identical TET2 mutations of the respective T-cell lymphoma clone. Thus, TET2-mutated haematopoietic precursor cells in AITL patients not only give rise to the T-cell lymphoma but also generate a large population of mutated mature B cells. Future studies will show whether this is a reason why AITL patients frequently also develop B-cell lymphomas. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

BIM mediates synergistic killing of B-cell acute lymphoblastic leukemia cells by BCL-2 and MEK inhibitors.

PubMed

Korfi, K; Smith, M; Swan, J; Somervaille, T C P; Dhomen, N; Marais, R

2016-04-07

B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive hematological disease that kills ~50% of adult patients. With the exception of some BCR-ABL1(+) patients who benefit from tyrosine kinase inhibitors, there are no effective targeted therapies for adult B-ALL patients and chemotherapy remains first-line therapy despite adverse side effects and poor efficacy. We show that, although the MEK/ERK pathway is activated in B-ALL cells driven by different oncogenes, MEK inhibition does not suppress B-ALL cell growth. However, MEK inhibition synergized with BCL-2/BCL-XL family inhibitors to suppress proliferation and induce apoptosis in B-ALL cells. We show that this synergism is mediated by the pro-apoptotic factor BIM, which is dephosphorylated as a result of MEK inhibition, allowing it to bind to and neutralize MCL-1, thereby enhancing BCL-2/BCL-XL inhibitor-induced cell death. This cooperative effect is observed in B-ALL cells driven by a range of genetic abnormalities and therefore has significant therapeutic potential.

BCL2-BH4 antagonist BDA-366 suppresses human myeloma growth

PubMed Central

Deng, Jiusheng; Park, Dongkyoo; Wang, Mengchang; Nooka, Ajay; Deng, Qiaoya; Matulis, Shannon; Kaufman, Jonathan; Lonial, Sagar; Boise, Lawrence H.; Galipeau, Jacques; Deng, Xingming

2016-01-01

Multiple myeloma (MM) is a heterogeneous plasma cell malignancy and remains incurable. B-cell lymphoma-2 (BCL2) protein correlates with the survival and the drug resistance of myeloma cells. BH3 mimetics have been developed to disrupt the binding between BCL2 and its pro-apoptotic BCL2 family partners for the treatment of MM, but with limited therapeutic efficacy. We recently identified a small molecule BDA-366 as a BCL2 BH4 domain antagonist, converting it from an anti-apoptotic into a pro-apoptotic molecule. In this study, we demonstrated that BDA-366 induces robust apoptosis in MM cell lines and primary MM cells by inducing BCL2 conformational change. Delivery of BDA-366 substantially suppressed the growth of human MM xenografts in NOD-scid/IL2Rγnull mice, without significant cytotoxic effects on normal hematopoietic cells or body weight. Thus, BDA-366 functions as a novel BH4-based BCL2 inhibitor and offers an entirely new tool for MM therapy. PMID:27049723

Aggressive B-cell lymphomas in patients with myelofibrosis receiving JAK1/2 inhibitor therapy.

PubMed

Porpaczy, Edit; Tripolt, Sabrina; Hoelbl-Kovacic, Andrea; Gisslinger, Bettina; Bago-Horvath, Zsuzsanna; Casanova-Hevia, Emilio; Clappier, Emmanuelle; Decker, Thomas; Fajmann, Sabine; Fux, Daniela A; Greiner, Georg; Gueltekin, Sinan; Heller, Gerwin; Herkner, Harald; Hoermann, Gregor; Kiladjian, Jean-Jacques; Kolbe, Thomas; Kornauth, Christoph; Krauth, Maria-Theresa; Kralovics, Robert; Muellauer, Leonhard; Mueller, Mathias; Prchal-Murphy, Michaela; Putz, Eva Maria; Raffoux, Emmanuel; Schiefer, Ana-Iris; Schmetterer, Klaus; Schneckenleithner, Christine; Simonitsch-Klupp, Ingrid; Skrabs, Cathrin; Sperr, Wolfgang R; Staber, Philipp Bernhard; Strobl, Birgit; Valent, Peter; Jaeger, Ulrich; Gisslinger, Heinz; Sexl, Veronika

2018-06-14

Inhibition of Janus-kinase 1/2 (JAK1/2) is a mainstay to treat myeloproliferative neoplasms (MPN). Sporadic observations reported the co-incidence of B-cell non-Hodgkin lymphomas during treatment of MPN with JAK1/2 inhibitors. We assessed 626 MPN patients including 69 with myelofibrosis receiving JAK1/2 inhibitors for lymphoma development. B-cell lymphomas evolved in 4/69 patients (5.8%) upon JAK1/2 inhibition compared to 2/557 (0.36%) with conventional treatment (16-fold increased risk). A similar 15-fold increase was observed in an independent cohort of 929 MPN patients. Considering primary myelofibrosis only (N=216), 3 lymphomas were observed in 31 inhibitor-treated patients (9.7%) versus 1/185 controls (0.54%). Lymphomas were of aggressive B-cell type, extra-nodal or leukemic with high MYC expression in the absence of JAK2 V617F or other MPN-associated mutations. Median time from initiation of inhibitor therapy to lymphoma diagnosis was 25 months. Clonal immunoglobulin gene rearrangements were already detected in the bone marrow during myelofibrosis in 16.3% of patients. Lymphomas occurring during JAK1/2 inhibitor treatment were preceded by a pre-existing B-cell clone in all 3 patients tested. Sequencing verified clonal identity in 2 patients. The effects of JAK1/2 inhibition were mirrored in Stat1 -/- mice: 16/24 mice developed a spontaneous myeloid hyperplasia with the concomitant presence of aberrant B-cells. Transplantations of bone marrow from diseased mice unmasked the outgrowth of a malignant B-cell clone evolving into aggressive B-cell leukemia-lymphoma. We conclude that JAK/STAT1 pathway inhibition in myelofibrosis is associated with an elevated frequency of aggressive B-cell lymphomas. Detection of a pre-existing B-cell clone may identify individuals at risk. Copyright © 2018 American Society of Hematology.

PRAD1, a candidate BCL1 oncogene: mapping and expression in centrocytic lymphoma.

PubMed Central

Rosenberg, C L; Wong, E; Petty, E M; Bale, A E; Tsujimoto, Y; Harris, N L; Arnold, A

1991-01-01

Rearrangement of the BCL1 (B-cell lymphoma 1) region on chromosome 11q13 appears to be highly characteristic of centrocytic lymphoma and also is found infrequently in other B-cell neoplasms. Rearrangement is thought to deregulate a nearby protooncogene, but transcribed sequences in the immediate vicinity of BCL1 breakpoints had not been identified. PRAD1, previously designated D11S287E, was identified on 11q13 as a chromosomal breakpoint region rearranged with the parathyroid hormone gene in a subset of parathyroid adenomas; this highly conserved putative oncogene, which encodes a novel cyclin, has been linked to BCL1 and implicated also in subsets of breast and squamous cell neoplasms with 11q13 amplification. We report pulsed-field gel electrophoresis data showing BCL1 and PRAD1 to be no more than 130 kilobases apart. PRAD1 mRNA is abundantly expressed in seven of seven centrocytic lymphomas (Kiel classification), in contrast to 13 closely related but noncentrocytic lymphomas. Three of the seven centrocytic lymphomas had detectable BCL1 DNA rearrangement. Also, two unusual cases of CLL with BCL1 rearrangement overexpressed PRAD1, in contrast to five CLL controls. Thus, PRAD1 is an excellent candidate "BCL1 oncogene." Its overexpression may be a key consequence of rearrangement of the BCL1 vicinity in B-cell neoplasms and a unifying pathogenetic feature in centrocytic lymphoma. Images PMID:1682919

ABT-199 (venetoclax) and BCL-2 inhibitors in clinical development.

PubMed

Cang, Shundong; Iragavarapu, Chaitanya; Savooji, John; Song, Yongping; Liu, Delong

2015-11-20

With the advent of new agents targeting CD20, Bruton's tyrosine kinase, and phosphoinositol-3 kinase for chronic lymphoid leukemia (CLL), more treatment options exist than ever before. B-cell lymphoma-2 (BCL-2) plays a major role in cellular apoptosis and is a druggable target. Small molecule inhibitors of BCL-2 are in active clinical studies. ABT-199 (venetoclax, RG7601, GDC-0199) has been granted breakthrough designation by FDA for relapsed or refractory CLL with 17p deletion. In this review, we summarized the latest clinical development of ABT-199/venetoclax and other novel agents targeting the BCL-2 proteins.

J chain and myocyte enhancer factor 2B are useful in differentiating classical Hodgkin lymphoma from nodular lymphocyte predominant Hodgkin lymphoma and primary mediastinal large B-cell lymphoma.

PubMed

Moore, Erika M; Swerdlow, Steven H; Gibson, Sarah E

2017-10-01

Although most classical Hodgkin lymphomas (CHLs) are easily distinguished from nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) and primary mediastinal large B-cell lymphoma (PMBL), cases with significant CD20 expression cause diagnostic confusion. Although the absence of OCT-2 and BOB.1 are useful in these circumstances, a variable proportion of CHLs are positive for these antigens. We investigated the utility of J chain and myocyte enhancer factor 2B (MEF2B) in the diagnosis of CHL; NLPHL; PMBL; T-cell/histiocyte-rich large B-cell lymphoma (TCRLBL); and B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and CHL, compared with OCT-2 and BOB.1. J chain and MEF2B highlighted lymphocyte predominant (LP) cells in 20/20 (100%) NLPHLs and were negative in 43/43 (100%) CHLs. Fourteen of 15 (93%) PMBLs and 4/4 (100%) TCRLBLs were MEF2B positive, whereas 67% of PMBLs and 50% of TCRLBLs were J chain positive. Three of 3 B-cell lymphomas, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and CHL, were negative for J chain and MEF2B. J chain and MEF2B were 100% sensitive and specific for NLPHL versus CHL. MEF2B was 100% sensitive and 98% specific for PMBL versus CHL. Whereas loss of OCT-2 and/or BOB.1 expression had a sensitivity of only 86% and specificity of 100% for CHL versus NLPHL, PMBL, and TCRLBL, lack of both J chain and MEF2B expression was 100% sensitive and 97% specific. J chain and MEF2B are highly sensitive and specific markers of NLPHL versus CHL; are particularly useful in highlighting LP cells; and, with rare exception, are of greater utility than OCT-2 and BOB.1 in differentiating CHL from NLPHL and other large B-cell lymphomas. Copyright © 2017 Elsevier Inc. All rights reserved.

Immunophenotypic and genetic characteristics of diffuse large B-cell lymphoma in Taiwan.

PubMed

Chang, Sheng-Tsung; Chen, Shang-Wen; Ho, Chung-Han; Kuo, Chun-Chi; Sakata, Seiji; Takeuchi, Kengo; Chuang, Shih-Sung

2016-11-01

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma type. The immunophenotypic and genetic features of DLBCL in Taiwan have not been characterized. In this study, we performed immunohistochemical analysis and interphase fluorescence in situ hybridization (FISH) using tissue microarray sections to investigate a cohort of unselected DLBCL cases in a single institution in Taiwan from 1990 to 2010. Of the 153 cases investigated, CD10, bcl-6, and MUM1 were expressed in 16.3%, 71.2%, and 71.9% cases, respectively, with 27.5% (n = 42) of cases being classified as having a germinal center B-cell (GCB) origin by the Hans algorithm. By FISH analysis, 19.6%, 4.6%, 26.1%, and 3.9% cases showed rearrangement at IGH, BCL2, BCL6, and MYC loci, respectively, including three (2.0%) cases of double-hit lymphoma. As compared with the non-GCB tumors, GCB tumors more frequently expressed CD10 (p < 0.001) and bcl-6 (p = 0.001) with less frequent expression of MUM1 (p = 0.007). Moreover, GCB tumors more frequently exhibited rearrangement at the BCL2 (p = 0.024) and MYC (p = 0.038) loci than non-GCB tumors. However, there was no survival difference between these two groups. In this first series of DLBCL evaluation from Taiwan, we found that the relative frequency of GCB tumors among DLBCL was low in most East Asian countries. There is a wide range of BCL2 rearrangement rates, higher in the West and lower in East Asia. A larger and/or national study is warranted to better understand the immunophenotypic and molecular features of DLBCL in Taiwan and their respective impact on patient survival. Copyright © 2016. Published by Elsevier B.V.

PRAD1, a candidate BCL1 oncogene: Mapping and expression in centrocytic lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenberg, C.L.; Arnold, A.; Harris, N.L.

Rearrangement of the BCL1 (B-cell lymphoma 1) region on chromosome 11q13 appears to be highly characteristic of centrocytic lymphoma and also is found infrequently in other B-cell neoplasma. Rearrangement is thought to deregulate a nearby protooncogene, but transcribed sequences in the immediate vicinity of BCL1 breakpoints had not been identified. PRAD1, previously designated D11S287E, was identified on 11q13 as a chromosomal breakpoint region rearranged with the parathyroid hormone gene in a subset of parathyroid adenomas; this highly conserved putative oncogene, which encodes a novel cyclin, has been linked to BCL1 and implicated also in subsets of breast and squamous cellmore » neoplasms with 11q13 amplification. The authors report pulsed-field gel electrophoresis data showing BCL1 and PRAD1 to be no more than 130 kilobases apart. PRAD1 mRNA is abundantly expressed in seven of seven centrocytic lymphomas (Kiel classification), in contrast to 13 closely related but noncentrocytic lymphomas. Three of the seven centrocytic lymphomas had detectable BCL1 DNA rearrangement. Also, two unusual cases of CLL and BCL1 rearrangement overexpressed PRAD1, in contrast to five CLL controls. Thus, PRAD1 is an excellent candidate BCL1 oncogene. Its overexpression may be a key consequence of rearrangement of the BCL1 vicinity in B-cell neoplasms and a unifying pathogenetic feature in centrocytic lymphoma.« less

APG-1252-12A induces mitochondria-dependent apoptosis through inhibiting the antiapoptotic proteins Bcl-2/Bcl-xl in HL-60 cells.

PubMed

Wang, Jing; Yang, Dajun; Luo, Qiuyun; Qiu, Miaozhen; Zhang, Lin; Li, Baoxia; Chen, Haibo; Yi, Hanjie; Yan, Xianglei; Li, Shuxia; Sun, Jian

2017-08-01

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Despite improved remission rates, current treatment regimens for AML are often associated with a very poor prognosis and adverse effects, necessitating more effective and safer agents. B-cell leukemia/lymphoma 2 (Bcl-2) family proteins regulate apoptotic pathway that can be targeted with small molecule inhibitors. APG-1252-12A is a Bcl-2 homology (BH)-3 mimetic that specifically binds to Bcl-2 and Bcl-xl, which has shown efficacy in some Bcl-2 dependent hematological cancers. In this study, we investigated whether APG-1252-12A inhibits the growth of five leukemia cell lines in a concentration- or time-dependent manner by MTS assay. Following treatment of AML cell line HL-60 with this compound, cell apoptosis was detected using flow cytometry and nuclear condensation was observed after Hoechst 33258 dye. Immunoblotting for cytochrome c, cleaved caspase-3 and PARP-1 cleavage was used to demonstrate the mechanism of inducing mitochondria-dependent apoptosis by APG-1252-12A. Our findings showed that this new compound inhibited cell proliferation in five leukemia cell lines and induced apoptotic death. There was a link between the level of Bcl-2 protein and IC50. APG-1252-12A targeted mitochondria and induced caspase-dependent apoptosis by inducing the HL-60 cell cytochrome c released, PARP cleavage and caspase activation. These data suggested that APG-1252-12A is a candidate drug for the in vivo analysis and clinical evaluation in AML.

MCL-1–dependent leukemia cells are more sensitive to chemotherapy than BCL-2–dependent counterparts

PubMed Central

Brunelle, Joslyn K.; Ryan, Jeremy; Yecies, Derek; Opferman, Joseph T.

2009-01-01

Myeloid cell leukemia sequence 1 (MCL-1) and B cell leukemia/lymphoma 2 (BCL-2) are anti-apoptotic proteins in the BCL-2 protein family often expressed in cancer. To compare the function of MCL-1 and BCL-2 in maintaining cancer survival, we constructed complementary mouse leukemia models based on Eμ-Myc expression in which either BCL-2 or MCL-1 are required for leukemia maintenance. We show that the principal anti-apoptotic mechanism of both BCL-2 and MCL-1 in these leukemias is to sequester pro-death BH3-only proteins rather than BAX and BAK. We find that the MCL-1–dependent leukemias are more sensitive to a wide range of chemotherapeutic agents acting by disparate mechanisms. In common across these varied treatments is that MCL-1 protein levels rapidly decrease in a proteosome-dependent fashion, whereas those of BCL-2 are stable. We demonstrate for the first time that two anti-apoptotic proteins can enable tumorigenesis equally well, but nonetheless differ in their influence on chemosensitivity. PMID:19948485

Bcl-2, Bcl-xL, and p-AKT are involved in neuroprotective effects of transcription factor Brn3b in an ocular hypertension rat model of glaucoma

PubMed Central

Phatak, Nitasha R.; Stankowska, Dorota L.

2016-01-01

Purpose Brn3b is a class IV POU domain transcription factor that plays an important role in the development of retinal ganglion cells (RGCs), RGC survival, and particularly axon growth and pathfinding. Our previous study demonstrated that recombinant adenoassociated virus serotype 2 (rAAV-2)–mediated overexpression of Brn3b in RGCs promoted neuroprotection in a rodent model of glaucoma. However, the mechanisms underlying neuroprotection of RGCs in rats overexpressing Brn3b in animal models of glaucoma remain largely unknown. The goal of this study was to understand some of the mechanisms underlying the neuroprotection of RGCs overexpressing Brn3b during intraocular pressure (IOP) elevation in Brown Norway rats. Methods One eye of Brown Norway rats (Rattus norvegicus) was injected with an AAV construct encoding either green fluorescent protein (GFP; recombinant adenoassociated virus–green fluorescent protein, rAAV-hSyn-GFP) or Brn3b (rAAV-hSyn-Brn3b). Expression of antiapoptotic proteins, including B cell lymphoma/leukemia-2 (Bcl-2) family proteins (Bcl-2 and Bcl-xL), and p-AKT, was observed following immunostaining of rat retinas that overexpress Brn3b. In a different set of experiments, intraocular pressure was elevated in one eye of Brown Norway rats, which was followed by intravitreal injection with AAV constructs encoding either GFP (rAAV-CMV-GFP) or Brn3b (rAAV-CMV-Brn3b). Retinal sections were stained for prosurvival factors, including Bcl-2, Bcl-XL, and p-AKT. Results AAV-mediated expression of transcription factor Brn3b promoted statistically significant upregulation of the Bcl-2 protein and increased expression of p-AKT in RGCs of Brown Norway rats. In addition, following IOP elevation, AAV-mediated Brn3b expression also statistically significantly increased levels of Bcl-2 in the RGC layer in Brown Norway rats. Conclusions Adenoassociated virus–mediated Brn3b protein overexpression may promote neuroprotection by upregulating key antiapoptotic

Bcl-2 inhibitors potentiate the cytotoxic effects of radiation in Bcl-2 overexpressing radioresistant tumor cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hara, Takamitsu; Omura-Minamisawa, Motoko; Chao Cheng

Purpose: Bcl-2, an inhibitor of apoptosis frequently shows elevated expression in human tumors, thus resulting in resistance to radiation therapy. Therefore, inhibiting Bcl-2 function may enhance the radiosensitivity of tumor cells. Tetrocarcin A (TC-A) and bcl-2 antisense oligonucleotides exhibit antitumor activity by inhibiting Bcl-2 function and transcription, respectively. We investigated whether these antitumor agents would enhance the cytotoxic effects of radiation in tumor cells overexpressing Bcl-2. Methods and materials: We used HeLa/bcl-2 cells, a stable Bcl-2-expressing cell line derived from wild-type HeLa (HeLa/wt) cells. Cells were incubated with TC-A and bcl-2 antisense oligonucleotides for 24 h after irradiation, and cellmore » viability was then determined. Apoptotic cells were quantified by flow cytometric assay. Results: The HeLa/bcl-2 cells were more resistant to radiation than HeLa/wt cells. At concentrations that are not inherently cytotoxic, both TC-A and bcl-2 antisense oligonucleotides increased the cytotoxic effects of radiation in HeLa/bcl-2 cells, but not in HeLa/wt cells. However, in HeLa/bcl-2 cells, additional treatment with TC-A in combination with radiation did not significantly increase apoptosis. Conclusions: The present results suggest that TC-A and bcl-2 antisense oligonucleotides reduce radioresistance of tumor cells overexpressing Bcl-2. Therefore, a combination of radiotherapy and Bcl-2 inhibitors may prove to be a useful therapeutic approach for treating tumors that overexpress Bcl-2.« less

Noxa/Bcl-2 Protein Interactions Contribute to Bortezomib Resistance in Human Lymphoid Cells*

PubMed Central

Smith, Alyson J.; Dai, Haiming; Correia, Cristina; Takahashi, Rie; Lee, Sun-Hee; Schmitz, Ingo; Kaufmann, Scott H.

2011-01-01

Previous studies have suggested that the BH3 domain of the proapoptotic Bcl-2 family member Noxa only interacts with the anti-apoptotic proteins Mcl-1 and A1 but not Bcl-2. In view of the similarity of the BH3 binding domains of these anti-apoptotic proteins as well as recent evidence that studies of isolated BH3 domains can potentially underestimate the binding between full-length Bcl-2 family members, we examined the interaction of full-length human Noxa with anti-apoptotic human Bcl-2 family members. Surface plasmon resonance using bacterially expressed proteins demonstrated that Noxa binds with mean dissociation constants (KD) of 3.4 nm for Mcl-1, 70 nm for Bcl-xL, and 250 nm for wild type human Bcl-2, demonstrating selectivity but not absolute specificity of Noxa for Mcl-1. Further analysis showed that the Noxa/Bcl-2 interaction reflected binding between the Noxa BH3 domain and the Bcl-2 BH3 binding groove. Analysis of proteins expressed in vivo demonstrated that Noxa and Bcl-2 can be pulled down together from a variety of cells. Moreover, when compared with wild type Bcl-2, certain lymphoma-derived Bcl-2 mutants bound Noxa up to 20-fold more tightly in vitro, pulled down more Noxa from cells, and protected cells against killing by transfected Noxa to a greater extent. When killing by bortezomib (an agent whose cytotoxicity in Jurkat T-cell leukemia cells is dependent on Noxa) was examined, apoptosis was enhanced by the Bcl-2/Bcl-xL antagonist ABT-737 or by Bcl-2 down-regulation and diminished by Bcl-2 overexpression. Collectively, these observations not only establish the ability of Noxa and Bcl-2 to interact but also identify Bcl-2 overexpression as a potential mechanism of bortezomib resistance. PMID:21454712

Aging causes exacerbated ischemic brain injury and failure of sevoflurane post-conditioning: role of B-cell lymphoma-2.

PubMed

Dong, P; Zhao, J; Zhang, Y; Dong, J; Zhang, L; Li, D; Li, L; Zhang, X; Yang, B; Lei, W

2014-09-05

Aging is associated with exacerbated brain injury after ischemic stroke. Herein, we explored the possible mechanisms underlying the age-associated exacerbated brain injury after ischemic stroke and determined whether therapeutic intervention with anesthetic post-conditioning would provide neuroprotection in aged rats. Male Fisher 344 rats (young, 4 months; aged, 24 months) underwent 2h of middle cerebral artery occlusion (MCAO) followed by 24-h reperfusion, with or without sevoflurane post-conditioning for 15 min immediately at the onset of reperfusion. Compared with young rats, aged rats showed larger infarct size, worse neurological scores and more TUNEL-positive cells in the penumbral cerebral cortex at 24h after MCAO. However, edema formation and motor coordination were similar in both groups. Sevoflurane reduced the infarct size, edema formation, and TUNEL-positive cells, and improved the neurological outcome in young rats but not in aged rats. Molecular studies revealed that basal expression of the anti-apoptotic molecule B-cell lymphoma-2 (Bcl-2) in the brain was lower in aged rats compared with young rats before MCAO, while basal expression of the pro-apoptotic molecule Bcl-2-associated X protein (Bax) showed similar levels in both groups. MCAO reduced Bcl-2 expression and increased Bax expression in both groups; however, Bax increase was more pronounced in aged rats. In young rats, sevoflurane reversed the above MCAO-induced changes. In contrast, sevoflurane failed to enhance Bcl-2 expression but decreased Bax expression in aged rats. These findings suggest that aging-associated reduction in basal Bcl-2 expression in the brain contributes to increased neuronal injury by enhancing cell apoptosis after ischemic stroke. Sevoflurane post-conditioning failed to provide neuroprotection in aged rats, probably due to its inability to increase Bcl-2 levels and prevent apoptosis in the brain. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

BCL11B is frequently downregulated in HTLV-1-infected T-cells through Tax-mediated proteasomal degradation.

PubMed

Permatasari, Happy Kurnia; Nakahata, Shingo; Ichikawa, Tomonaga; Morishita, Kazuhiro

2017-08-26

Human T-cell leukemia virus type 1 (HTLV-1) is a causative agent of adult T-cell leukemia-lymphoma (ATLL). The HTLV-1-encoded protein Tax plays important roles in the proliferation of HTLV-1-infected T-cells by affecting cellular proteins. In this study, we showed that Tax transcriptionally and post-transcriptionally downregulates the expression of the tumor suppressor gene B-cell leukemia/lymphoma 11B (BCL11B), which encodes a lymphoid-related transcription factor. BCL11B expression was downregulated in HTLV-1-infected T-cell lines at the mRNA and protein levels, and forced expression of BCL11B suppressed the proliferation of these cells. The proteasomal inhibitor MG132 increased BCL11B expression in HTLV-1-infected cell lines, and colocalization of Tax with BCL11B was detected in the cytoplasm of HTLV-1-infected T-cells following MG132 treatment. shRNA knock-down of Tax expression also increased the expression of BCL11B in HTLV-1-infected cells. Moreover, we found that Tax physically binds to BCL11B protein and induces the polyubiquitination of BCL11B and proteasome-dependent degradation of BCL11B. Thus, inactivation of BCL11B by Tax protein may play an important role in the Tax-mediated leukemogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Homology modeling and docking studies of human Bcl-2L10 protein.

PubMed

Bhargavi, K; Kalyan Chaitanya, P; Ramasree, D; Vasavi, M; Murthy, D K; Uma, V

2010-12-01

Cancer, an unrestrained proliferation of cells, is one of the lead cause of death. Nearly 12.5 million people are diagnosed with cancer worldwide, 7.5 million people die of which 2.5 million cases are from India. Major cause for cancer is restriction of programmed cell death (apoptosis). Multiple signaling pathways regulate apoptosis. Bcl-2 (B - Cell Lymphomas-2) family proteins play a vital role as central regulators of apoptosis. Bcl-2L10, a novel anti-apoptotic protein, blocks apoptosis by mitochondrial dependent mechanism. The present study evaluates the 3D structure of Bcl-2L10 protein using homology modeling and aims to understand plausible functional and binding interactions between Bcl-2L10 with BH3 domain of BAX using protein - protein docking. The docking studies show binding of BH3 domain at Lys 110, Trp-111, Pro-115, Glu-119 and Asp-127 in the groove of BH 1, 2 and 3 domains of Bcl-2L10. Heterodimerization of anti-apoptotic Bcl-2 and BH3 domain of pro-apoptotic Bcl-2 proteins instigates apoptosis. Profound understanding of Bcl-2 pathway may prove useful in identification of future therapeutic targets for cancer.

High levels of bcl-2 protein expression do not correlate with genetic abnormalities but predict worse prognosis in patients with lymphoblastic lymphoma.

PubMed

Gu, Yajun; Pan, Yi; Meng, Bin; Guan, Bingxin; Fu, Kai; Sun, Baocun; Zheng, Fang

2013-06-01

We aimed to investigate bcl-2, bcl-6, and c-myc rearrangements in patients with lymphoblastic lymphoma (LBL), especially focus on the correlation of protein expression with genetic abnormalities. Moreover, their prognostic significance was further analyzed in LBL. Protein expression and genetic abnormalities of bcl-2, bcl-6, and c-myc were investigated in microarrayed tumors from 33 cases of T cell LBL and eight cases of B cell lineage. Immunohistochemical (IHC) staining was performed to evaluate protein expression, including bcl-2, bcl-6, c-myc, TdT, CD1α, CD34, Ki-67, PAX-5, CD2, CD3, CD4, CD8, and CD20. Genetic abnormalities of bcl-2, bcl-6, and c-myc were detected by dual color fluorescence in situ hybridization (FISH). Bcl-2 protein was positive in 51.2 % (21/41) of the patients, bcl-6 protein in 7.3 % (three out of 41), and c-myc protein in 78.0 % (32/41). Bcl-2 breakpoint was found in two cases by FISH analysis. There was no evidence of bcl-6 or c-myc rearrangement in patients with LBL. However, both gene gain and loss events occurred in bcl-2, bcl-6, and c-myc. A univariate analysis showed that stage III or IV, elevated lactate dehydrogenase (LDH), and positivity for bcl-2 protein were associated with shorter survival (p<0.05). Enhanced protein expression and detectable genetic abnormalities of bcl-2, bcl-6, and c-myc were observed in patients with LBL. No statistical correlation was found between IHC results and cytogenetic findings. Stage III or IV, elevated LDH, and positivity for bcl-2 protein were identified as adverse prognostic factors. The patients with more adverse factors would have increasingly worse prognosis.

MYC protein expression and genetic alterations have prognostic impact in patients with diffuse large B-cell lymphoma treated with immunochemotherapy

PubMed Central

Valera, Alexandra; López-Guillermo, Armando; Cardesa-Salzmann, Teresa; Climent, Fina; González-Barca, Eva; Mercadal, Santiago; Espinosa, Íñigo; Novelli, Silvana; Briones, Javier; Mate, José L.; Salamero, Olga; Sancho, Juan M.; Arenillas, Leonor; Serrano, Sergi; Erill, Nadina; Martínez, Daniel; Castillo, Paola; Rovira, Jordina; Martínez, Antonio; Campo, Elias; Colomo, Luis

2013-01-01

MYC alterations influence the survival of patients with diffuse large B-cell lymphoma. Most studies have focused on MYC translocations but there is little information regarding the impact of numerical alterations and protein expression. We analyzed the genetic alterations and protein expression of MYC, BCL2, BCL6, and MALT1 in 219 cases of diffuse large B-cell lymphoma. MYC rearrangement occurred as the sole abnormality (MYC single-hit) in 3% of cases, MYC and concurrent BCL2 and/or BCL6 rearrangements (MYC double/triple-hit) in 4%, MYC amplifications in 2% and MYC gains in 19%. MYC single-hit, MYC double/triple-hit and MYC amplifications, but not MYC gains or other gene rearrangements, were associated with unfavorable progression-free survival and overall survival. MYC protein expression, evaluated using computerized image analysis, captured the unfavorable prognosis of MYC translocations/amplifications and identified an additional subset of patients without gene alterations but with similar poor prognosis. Patients with tumors expressing both MYC/BCL2 had the worst prognosis, whereas those with double-negative tumors had the best outcome. High MYC expression was associated with shorter overall survival irrespectively of the International Prognostic Index and BCL2 expression. In conclusion, MYC protein expression identifies a subset of diffuse large B-cell lymphoma with very poor prognosis independently of gene alterations and other prognostic parameters. PMID:23716551

MYC protein expression and genetic alterations have prognostic impact in patients with diffuse large B-cell lymphoma treated with immunochemotherapy.

PubMed

Valera, Alexandra; López-Guillermo, Armando; Cardesa-Salzmann, Teresa; Climent, Fina; González-Barca, Eva; Mercadal, Santiago; Espinosa, Iñigo; Novelli, Silvana; Briones, Javier; Mate, José L; Salamero, Olga; Sancho, Juan M; Arenillas, Leonor; Serrano, Sergi; Erill, Nadina; Martínez, Daniel; Castillo, Paola; Rovira, Jordina; Martínez, Antonio; Campo, Elias; Colomo, Luis

2013-10-01

MYC alterations influence the survival of patients with diffuse large B-cell lymphoma. Most studies have focused on MYC translocations but there is little information regarding the impact of numerical alterations and protein expression. We analyzed the genetic alterations and protein expression of MYC, BCL2, BCL6, and MALT1 in 219 cases of diffuse large B-cell lymphoma. MYC rearrangement occurred as the sole abnormality (MYC single-hit) in 3% of cases, MYC and concurrent BCL2 and/or BCL6 rearrangements (MYC double/triple-hit) in 4%, MYC amplifications in 2% and MYC gains in 19%. MYC single-hit, MYC double/triple-hit and MYC amplifications, but not MYC gains or other gene rearrangements, were associated with unfavorable progression-free survival and overall survival. MYC protein expression, evaluated using computerized image analysis, captured the unfavorable prognosis of MYC translocations/amplifications and identified an additional subset of patients without gene alterations but with similar poor prognosis. Patients with tumors expressing both MYC/BCL2 had the worst prognosis, whereas those with double-negative tumors had the best outcome. High MYC expression was associated with shorter overall survival irrespectively of the International Prognostic Index and BCL2 expression. In conclusion, MYC protein expression identifies a subset of diffuse large B-cell lymphoma with very poor prognosis independently of gene alterations and other prognostic parameters.

Biological rational for sequential targeting of Bruton tyrosine kinase and Bcl-2 to overcome CD40-induced ABT-199 resistance in mantle cell lymphoma.

PubMed

Chiron, David; Dousset, Christelle; Brosseau, Carole; Touzeau, Cyrille; Maïga, Sophie; Moreau, Philippe; Pellat-Deceunynck, Catherine; Le Gouill, Steven; Amiot, Martine

2015-04-20

The aggressive biological behavior of mantle cell lymphoma (MCL) and its short response to current treatment highlight a great need for better rational therapy. Herein, we investigate the ability of ABT-199, the Bcl-2-selective BH3 mimetic, to kill MCL cells. Among MCL cell lines tested (n = 8), only three were sensitive (LD50 < 200 nM). In contrast, all primary MCL samples tested (n = 11) were highly sensitive to ABT-199 (LD50 < 10 nM). Mcl-1 and Bcl-xL both confer resistance to ABT-199-specific killing and BCL2/(BCLXL+MCL1) mRNA ratio is a strong predictor of sensitivity. By mimicking the microenvironment through CD40 stimulation, we show that ABT-199 sensitivity is impaired through activation of NF-kB pathway and Bcl-x(L) up-regulation. We further demonstrate that resistance is rapidly lost when MCL cells detach from CD40L-expressing fibroblasts. It has been reported that ibrutinib induces lymphocytosis in vivo holding off malignant cells from their protective microenvironment. We show here for two patients undergoing ibrutinib therapy that mobilized MCL cells are highly sensitive to ABT-199. These results provide evidence that in situ ABT-199 resistance can be overcome when MCL cells escape from the lymph nodes. Altogether, our data support the clinical application of ABT-199 therapy both as a single agent and in sequential combination with BTK inhibitors.

Immunohistochemical expression of protein 53, murine double minute 2, B-cell lymphoma 2, and proliferating cell nuclear antigen in odontogenic cysts and keratocystic odontogenic tumor.

PubMed

Galvão, Hebel Cavalcanti; Gordón-Núñez, Manuel Antonio; de Amorim, Rivadavio Fernandes Batista; Freitas, Roseana de Almeida; de Souza, Lelia Batista

2013-01-01

Even though odontogenic cysts share a similar histogenesis, they show different growth and differentiation profile due to differences in the proliferative cellular activity. We perform an immunohistochemical assessment of protein 53 (p53), proliferating cell nuclear antigen (PCNA), B-cell lymphoma 2 (bcl-2), and murine double minute 2 (MDM2) expression in odontogenic cysts and keratocystic odontogenic tumor analyzing their correlation with the biological behavior of these lesions. By the streptavidin-biotin-peroxidase method with antibodies against p53, PCNA, bcl-2, and MDM2 proteins, 11 radicular cysts, 11 dentigerous cysts, and 11 keratocystic odontogenic tumor were analyzed. The non-parametric Mann-Whitney U-test and Kruskall-Wallis test (P ≤ 0.05) were used to analyze the data. Immunopositivity for PCNA was observed in all cases appraised, predominantly in the suprabasal layer of keratocystic odontogenic tumor epithelial lining (SD ± 19.44), but no significant differences were found among the groups of lesions. Bcl-2 immunoexpression was observed especially in the basal layer of keratocystic odontogenic tumor. PCNA LI was significantly higher than bcl-2 LI in keratocystic odontogenic tumor. MDM2 and p53 immunoexpression were not detected in the lesions studied. Among the evaluated lesions, the keratocystic odontogenic tumor showed different immunoexpression of the proliferation and apoptosis markers. The results of this study suggest that the keratocystic odontogenic tumor presents distinct biological behavior of the odontogenic cysts, as for the processes of proliferation, apoptosis, and differentiation, reinforcing the information in favor of the neoplastic nature of this lesion.

Development of chronic allergic responses by dampening Bcl6-mediated suppressor activity in memory T helper 2 cells

PubMed Central

Ogasawara, Takashi; Hatano, Masahiko; Satake, Hisae; Ikari, Jun; Taniguchi, Toshibumi; Tsuruoka, Nobuhide; Watanabe-Takano, Haruko; Fujimura, Lisa; Sakamoto, Akemi; Hirata, Hirokuni; Sugiyama, Kumiya; Fukushima, Yasutsugu; Nakae, Susumu; Matsumoto, Kenji; Saito, Hirohisa; Fukuda, Takeshi; Kurasawa, Kazuhiro; Tatsumi, Koichiro; Tokuhisa, Takeshi

2017-01-01

Mice deficient in the transcriptional repressor B-cell CLL/lymphoma 6 (Bcl6) exhibit similar T helper 2 (TH2) immune responses as patients with allergic diseases. However, the molecular mechanisms underlying Bcl6-directed regulation of TH2 cytokine genes remain unclear. We identified multiple Bcl6/STAT binding sites (BSs) in TH2 cytokine gene loci. We found that Bcl6 is modestly associated with the BSs, and it had no significant effect on cytokine production in newly differentiated TH2 cells. Contrarily, in memory TH2 (mTH2) cells derived from adaptively transferred TH2 effectors, Bcl6 outcompeted STAT5 for binding to TH2 cytokine gene loci, particularly Interleukin4 (Il4) loci, and attenuated GATA binding protein 3 (GATA3) binding to highly conserved intron enhancer regions in mTH2 cells. Bcl6 suppressed cytokine production epigenetically in mTH2 cells to negatively tune histone acetylation at TH2 cytokine gene loci, including Il4 loci. In addition, IL-33, a pro-TH2 cytokine, diminished Bcl6’s association with loci to which GATA3 recruitment was inversely augmented, resulting in altered IL-4, but not IL-5 and IL-13, production in mTH2 cells but no altered production in newly differentiated TH2 cells. Use of a murine asthma model that generates high levels of pro-TH2 cytokines, such as IL-33, suggested that the suppressive function of Bcl6 in mTH2 cells is abolished in severe asthma. These findings indicate a role of the interaction between TH2-promoting factors and Bcl6 in promoting appropriate IL-4 production in mTH2 cells and suggest that chronic allergic diseases involve the TH2-promoting factor-mediated functional breakdown of Bcl6, resulting in allergy exacerbation. PMID:28096407

Interphase detection of immunoglobulin heavy chain gene translocations with specific oncogene loci in 173 patients with B-cell lymphoma.

PubMed

Tamura, A; Miura, I; Iida, S; Yokota, S; Horiike, S; Nishida, K; Fujii, H; Nakamura, S; Seto, M; Ueda, R; Taniwaki, M

2001-08-01

To detect immunoglobulin heavy chain (IGH) gene translocations with specific oncogene loci, we established an interphase cytogenetic approach using double-color fluorescence in situ hybridization (DC-FISH), which we used to analyze 173 patients with B-cell lymphoma. DC-FISH using the IGH gene (14q32.3) in combination with c-MYC (8q24.1), BCL1 (11q13.3), BCL2 (18q21.3), BCL6 (3q27), and PAX-5 (9p13) gene probes detected IGH translocations in 70 (40.5%) of 173 patients. The partner genes involved in IGH translocations were identified in 56 (80%) of 70 patients, and fusion of the IGH gene with specific oncogenes was detected in 53 of 56 patients, particularly in interphase nuclei of 28 patients for whom cytogenetic analysis was not informative. The most common partner gene was BCL2 (19 patients; 27% of IGH translocation-positive patients), followed by BCL6 (16; 23%), BCL1 (11; 16%), c-MYC (7; 10%), and PAX-5 (2; 3%). These oncogenes were closely associated with subtypes of B-cell lymphoma. The other partners were 19q13 (BCL3), 6p25 (MUM1/IRF4), 1q36, and chromosome 8 identified in one patient each. Six of the nine patients with add(14)(q32) showed a BCL6/IGH translocation. Double translocations of the IGH gene were found in three patients; c-MYC+BCL1, c-MYC+BCL2, and c-MYC+BCL6 in each one. Interphase FISH using specific IGH-translocation probes is valuable for defining clinically meaningful subgroups of B-cell lymphoma.

Upregulated miR-29b promotes neuronal cell death by inhibiting Bcl2L2 after ischemic brain injury.

PubMed

Shi, Guodong; Liu, Yang; Liu, Tielong; Yan, Wangjun; Liu, Xiaowei; Wang, Yuan; Shi, Jiangang; Jia, Lianshun

2012-01-01

It is increasingly clear that microRNAs (miRNAs) play an important role in controlling cell survival. However, the functional significance of miRNAs in ischemic brain injury remains poorly understood. In the present study, we assayed the expression levels of miR-29b after ischemic brain injury, and defined the target genes and biological functions of miR-29b. We found that the miR-29b levels were significantly increased in rat brain after transient middle cerebral artery occlusion and neurons after oxygen-glucose deprivation. Moreover, ectopic expression of miR-29b promoted neuronal cell death, whereas its repression decreased cell death. Furthermore, we verified that miR-29b directly targeted and inhibited Bcl2L2 gene expression, and then increased neuronal cell death. Importantly, Bcl2L2 overexpression rescued neuronal cell death induced by miR-29b. These results suggest an important role of miR-29b in regulating neuronal cell death, thus offering a new target for the development of therapeutic agents against ischemic brain injury.

MicroRNA-15b deteriorates hypoxia/reoxygenation-induced cardiomyocyte apoptosis by downregulating Bcl-2 and MAPK3.

PubMed

Liu, Yaling; Yang, Liqun; Yin, Jiemin; Su, Diansan; Pan, Zhiying; Li, Peiying; Wang, Xiaodong

2018-01-01

To investigate the role of miRNA-15b in cardiomyocyte apoptosis after ischemia reperfusion injury in acute myocardial infarction (AMI), we conducted the AMI rat model by using left anterior descending ligation and performed hypoxia/reoxygenation experiments in H9c2 cells. MiRNA-15b was measured by quantitative reverse transcription PCR (qRT-PCR). Cardiomyocyte apoptosis was determined by terminal deoxynucleotide transferase dUTP nick end labeling staining. Synthesized miRNA-15b mimic and inhibitor were transfected into H9c2 cells by Lipofectamine regent. RNA expression of B cell lymphoma/leukemia-2 (Bcl-2) and mitogen-activated protein kinase 3 (MAPK3) was examined by qRT-PCR and their protein expression was determined by western blot. Ischemia reperfusion increased miRNA-15b expression in the ischemic rat heart and resulted more severe cardiomyocytes apoptosis. In H9c2 cells, hypoxia/reoxygenation induced increased miRNA-15b expression and augmented cardiomyocyte apoptosis observed at 24 hours after 24-hour hypoxia. Compared with the vehicle group, miRNA-15b mimic further raised miRNA-15b level and increased cardiomyocyte apoptosis, whereas miRNA-15b inhibitor suppressed miRNA-15b expression and protected cardiomyocytes from apoptosis. Although the mRNA expression of the target genes Bcl-2 and MAPK3 was not changed significantly, the protein expression of these two genes were markedly reduced after miRNA-15b mimic treatment and significantly increased after transfected with miRNA-15b inhibitors. In conclusion, miRNA-15b deteriorates cardiomyocyte apoptosis by post-transcriptionally downregulating the expression of Bcl-2 and MAPK3. © American Federation for Medical Research (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Synthesis and Biological Evaluation of Apogossypolone Derivatives as Pan-active Inhibitors of Anti-apoptotic B-Cell Lymphoma/Leukemia-2 (Bcl-2) Family Proteins

PubMed Central

Wei, Jun; Kitada, Shinichi; Stebbins, John L.; Placzek, William; Zhai, Dayong; Wu, Bainan; Rega, Michele F.; Zhang, Ziming; Cellitti, Jason; Yang, Li; Dahl, Russell; Reed, John C.; Pellecchia, Maurizio

2010-01-01

Overexpression of anti-apoptotic Bcl-2 family proteins is commonly related with tumor maintenance, progression, and chemoresistance. Inhibition of these anti-apoptotic proteins is an attractive approach for cancer therapy. Guided by nuclear magnetic resonance (NMR) binding assays, a series of 5, 5′ substituted compound 6a (Apogossypolone) derivatives was synthesized and identified pan-active antagonists of anti-apoptotic Bcl-2 family proteins, with binding potency in the low micromolar to nanomolar range. Compound 6f inhibits the binding of BH3 peptides to Bcl-XL, Bcl-2 and Mcl-1 with IC50 values of 3.10, 3.12 and 2.05 μM, respectively. In a cellular assay, 6f potently inhibits cell growth in several human cancer cell lines in a dose-dependent manner. Compound 6f further displays in vivo efficacy in transgenic mice and demonstrated superior single-agent antitumor efficacy in a PPC-1 mouse xenograft model. Together with its negligible toxicity, compound 6f represents a promising drug lead for the development of novel apoptosis-based therapies for cancer. PMID:21033669

Overexpression of nucleolin in chronic lymphocytic leukemia cells induces stabilization of bcl2 mRNA

PubMed Central

Otake, Yoko; Soundararajan, Sridharan; Sengupta, Tapas K.; Kio, Ebenezer A.; Smith, James C.; Pineda-Roman, Mauricio; Stuart, Robert K.; Spicer, Eleanor K.

2007-01-01

B-cell chronic lymphocytic leukemia (CLL) is characterized by the accumulation of clonal B cells that are resistant to apoptosis as a result of bcl2 oncogene overexpression. Studies were done to determine the mechanism for the up-regulation of bcl-2 protein observed in CD19+ CLL cells compared with CD19+ B cells from healthy volunteers. The 11-fold higher level of bcl-2 protein in CLL cells was positively correlated with a 26-fold elevation in the cytosolic level of nucleolin, a bcl2 mRNA–stabilizing protein. Measurements of the bcl2 heterogeneous nuclear/bcl2 mRNA (hnRNA)/mRNA ratios and the rates of bcl2 mRNA decay in cell extracts indicated that the 3-fold higher steady-state level of bcl2 mRNA in CLL cells was the result of increased bcl2 mRNA stability. Nucleolin was present throughout the nucleus and cytoplasm of CLL cells, whereas in normal B cells nucleolin was only detected in the nucleus. The addition of recombinant human nucleolin to extracts of normal B cells markedly slowed the rate of bcl2 mRNA decay. SiRNA knockdown of nucleolin in MCF-7 cells resulted in decreased levels of bcl2 mRNA and protein but no change in β-actin. These results indicate that bcl-2 overexpression in CLL cells is related to stabilization of bcl2 mRNA by nucleolin. PMID:17179226

A leukemic double-hit follicular lymphoma associated with a complex variant translocation, t(8;14;18)(q24;q32;q21), involving BCL2, MYC, and IGH.

PubMed

Minakata, Daisuke; Sato, Kazuya; Ikeda, Takashi; Toda, Yumiko; Ito, Shoko; Mashima, Kiyomi; Umino, Kento; Nakano, Hirofumi; Yamasaki, Ryoko; Morita, Kaoru; Kawasaki, Yasufumi; Sugimoto, Miyuki; Yamamoto, Chihiro; Ashizawa, Masahiro; Hatano, Kaoru; Oh, Iekuni; Fujiwara, Shin-Ichiro; Ohmine, Ken; Kawata, Hirotoshi; Muroi, Kazuo; Miura, Ikuo; Kanda, Yoshinobu

2018-01-01

Double-hit lymphoma (DHL) is defined as lymphoma with concurrent BCL2 and MYC translocations. While the most common histological subtype of DHL is diffuse large B-cell lymphoma, the present patient had leukemic follicular lymphoma (FL). A 52-year-old man was admitted to our hospital due to general fatigue and cervical and inguinal lymph node swelling. The patient was leukemic and the pathological diagnosis of the inguinal lymph node was FL grade 1. Chromosomal analysis revealed a complex karyotype including a rare three-way translocation t(8;14;18)(q24;q32;q21) involving the BCL2, MYC, and IGH genes. Based on a combination of fluorescence in situ hybridization (FISH), using BCL2, MYC and IGH, and spectral karyotyping (SKY), the karyotype was interpreted as being the result of a multistep mechanism in which the precursor B-cell gained t(14;18) in the bone marrow and acquired a translocation between der(14)t(14;18) and chromosome 8 in the germinal center, resulting in t(8;14;18). The pathological diagnosis was consistently FL, not only at presentation but even after a second relapse. The patient responded well to standard chemotherapies but relapsed after a short remission. This patient is a unique case of leukemic DH-FL with t(8;14;18) that remained in FL even at a second relapse. Copyright © 2017 Elsevier Inc. All rights reserved.

Targeting MUC1-C suppresses BCL2A1 in triple-negative breast cancer.

PubMed

Hiraki, Masayuki; Maeda, Takahiro; Mehrotra, Neha; Jin, Caining; Alam, Maroof; Bouillez, Audrey; Hata, Tsuyoshi; Tagde, Ashujit; Keating, Amy; Kharbanda, Surender; Singh, Harpal; Kufe, Donald

2018-01-01

B-cell lymphoma 2-related protein A1 (BCL2A1) is a member of the BCL-2 family of anti-apoptotic proteins that confers resistance to treatment with anti-cancer drugs; however, there are presently no agents that target BCL2A1. The MUC1-C oncoprotein is aberrantly expressed in triple-negative breast cancer (TNBC) cells, induces the epithelial-mesenchymal transition (EMT) and promotes anti-cancer drug resistance. The present study demonstrates that targeting MUC1-C genetically and pharmacologically in TNBC cells results in the downregulation of BCL2A1 expression. The results show that MUC1-C activates the BCL2A1 gene by an NF-κB p65-mediated mechanism, linking this pathway with the induction of EMT. The MCL-1 anti-apoptotic protein is also of importance for the survival of TNBC cells and is an attractive target for drug development. We found that inhibiting MCL-1 with the highly specific MS1 peptide results in the activation of the MUC1-C→NF-κB→BCL2A1 pathway. In addition, selection of TNBC cells for resistance to ABT-737, which inhibits BCL-2, BCL-xL and BCL-W but not MCL-1 or BCL2A1, is associated with the upregulation of MUC1-C and BCL2A1 expression. Targeting MUC1-C in ABT-737-resistant TNBC cells suppresses BCL2A1 and induces death, which is of potential therapeutic importance. These findings indicate that MUC1-C is a target for the treatment of TNBCs unresponsive to agents that inhibit anti-apoptotic members of the BCL-2 family.

2B4-SAP signaling is required for the priming of naive CD8+ T cells by antigen-expressing B cells and B lymphoma cells

PubMed Central

2017-01-01

ABSTRACT Mutations in SH2D1A gene that encodes SAP (SLAM-associated protein) result in X-linked lymphoproliferative disease (XLP), a rare primary immunodeficiency disease defined by exquisite sensitivity to the B-lymphotropic Epstein–Barr virus (EBV) and B cell lymphomas. However, the precise mechanism of how the loss of SAP function contributes to extreme vulnerability to EBV and the development of B cell lymphomas remains unclear. Here, we investigate the hypothesis that SAP is critical for CD8+ T cell immune surveillance of antigen (Ag)-expressing B cells or B lymphoma cells under conditions of defined T cell receptor (TCR) signaling. Sh2d1a−/− CD8+ T cells exhibited greatly diminished proliferation relative to wild type when Ag-presenting-B cells or -B lymphoma cells served as the primary Ag-presenting cell (APC). By contrast, Sh2d1a−/− CD8+ T cells responded equivalently to wild-type CD8+ T cells when B cell-depleted splenocytes, melanoma cells or breast carcinoma cells performed Ag presentation. Through application of signaling lymphocyte activation molecule (SLAM) family receptor blocking antibodies or SLAM family receptor-deficient CD8+ T cells and APCs, we found that CD48 engagement on the B cell surface by 2B4 is crucial for initiating SAP-dependent signaling required for the Ag-driven CD8+ T cell proliferation and differentiation. Altogether, a pivotal role for SAP in promoting the expansion and differentiation of B cell-primed viral-specific naive CD8+ T cells may explain the selective immune deficiency of XLP patients to EBV and B cell lymphomas. PMID:28344876

2B4-SAP signaling is required for the priming of naive CD8+ T cells by antigen-expressing B cells and B lymphoma cells.

PubMed

Huang, Yu-Hsuan; Tsai, Kevin; Tan, Sara Y; Kang, Sohyeong; Ford, Mandy L; Harder, Kenneth W; Priatel, John J

2017-01-01

Mutations in SH2D1A gene that encodes SAP (SLAM-associated protein) result in X-linked lymphoproliferative disease (XLP), a rare primary immunodeficiency disease defined by exquisite sensitivity to the B-lymphotropic Epstein-Barr virus (EBV) and B cell lymphomas. However, the precise mechanism of how the loss of SAP function contributes to extreme vulnerability to EBV and the development of B cell lymphomas remains unclear. Here, we investigate the hypothesis that SAP is critical for CD8 + T cell immune surveillance of antigen (Ag)-expressing B cells or B lymphoma cells under conditions of defined T cell receptor (TCR) signaling. Sh2d1a - / - CD8 + T cells exhibited greatly diminished proliferation relative to wild type when Ag-presenting-B cells or -B lymphoma cells served as the primary Ag-presenting cell (APC). By contrast, Sh2d1a - / - CD8 + T cells responded equivalently to wild-type CD8 + T cells when B cell-depleted splenocytes, melanoma cells or breast carcinoma cells performed Ag presentation. Through application of signaling lymphocyte activation molecule (SLAM) family receptor blocking antibodies or SLAM family receptor-deficient CD8 + T cells and APCs, we found that CD48 engagement on the B cell surface by 2B4 is crucial for initiating SAP-dependent signaling required for the Ag-driven CD8 + T cell proliferation and differentiation. Altogether, a pivotal role for SAP in promoting the expansion and differentiation of B cell-primed viral-specific naive CD8 + T cells may explain the selective immune deficiency of XLP patients to EBV and B cell lymphomas.

Induction of apoptosis and suppression of tumor growth by Nur77-derived Bcl-2 converting peptide in chemoresistant lung cancer cells.

PubMed

Pearce, Martin C; Gamble, John T; Kopparapu, Prasad R; O'Donnell, Edmond F; Mueller, Monica J; Jang, Hyo Sang; Greenwood, Julie A; Satterthwait, Arnold C; Tanguay, Robert L; Zhang, Xiao-Kun; Kolluri, Siva Kumar

2018-05-25

Resistance to chemotherapy is a major cause of treatment failure and poor overall survival in patients with lung cancer. Identification of molecular targets present in resistant cancer cells is essential for addressing therapeutic resistance and prolonging lung cancer patient survival. Members of the B-cell lymphoma 2 (Bcl-2) family of proteins are associated with chemotherapeutic resistance. In this study, we found that pro-survival protein Bcl-2 is upregulated in paclitaxel resistant cells, potentially contributing to chemotherapy resistance. To exploit the increase in Bcl-2 expression for targeting therapy resistance, we investigated the effects of a peptide derived from the nuclear receptor Nur77 that converts Bcl-2 from an anti-apoptotic protein to a pro-apoptotic protein. The Nur77 derived peptide preferentially induced apoptosis in paclitaxel-resistant cancer cells with high expression of Bcl-2. This peptide also induced apoptosis of multidrug resistant H69AR lung cancer cells that express Bcl-2 and inhibited their growth in 3D spheroids. The Nur77 peptide strongly suppressed the growth of paclitaxel-resistant lung cancer cells in a zebrafish xenograft tumor model. Taken together, our data supports a new strategy for treating lung cancers that acquire resistance to chemotherapy through overexpression of Bcl-2.

Conditional knockdown of BCL2A1 reveals rate-limiting roles in BCR-dependent B-cell survival

PubMed Central

Sochalska, M; Ottina, E; Tuzlak, S; Herzog, S; Herold, M; Villunger, A

2016-01-01

Bcl2 family proteins control mitochondrial apoptosis and its members exert critical cell type and differentiation stage-specific functions, acting as barriers against autoimmunity or transformation. Anti-apoptotic Bcl2a1/Bfl1/A1 is frequently deregulated in different types of blood cancers in humans but its physiological role is poorly understood as quadruplication of the Bcl2a1 gene locus in mice hampers conventional gene targeting strategies. Transgenic overexpression of A1, deletion of the A1-a paralogue or constitutive knockdown in the hematopoietic compartment of mice by RNAi suggested rate-limiting roles in lymphocyte development, granulopoiesis and mast cell activation. Here we report on the consequences of conditional knockdown of A1 protein expression using a reverse transactivator (rtTA)-driven approach that highlights a critical role for this Bcl2 family member in the maintenance of mature B-cell homeostasis. Furthermore, we define the A1/Bim (Bcl-2 interacting mediator of cell death) axis as a target of key kinases mediating B-cell receptor (BCR)-dependent survival signals, such as, spleen tyrosine kinase (Syk) and Brutons tyrosine kinase (Btk). As such, A1 represents a putative target for the treatment of B-cell-related pathologies depending on hyperactivation of BCR-emanating survival signals and loss of A1 expression accounts, in part, for the pro-apoptotic effects of Syk- or Btk inhibitors that rely on the ‘BH3-only' protein Bim for cell killing. PMID:26450454

The inhibition of PI3K and NFκB promoted curcumin-induced cell cycle arrest at G2/M via altering polyamine metabolism in Bcl-2 overexpressing MCF-7 breast cancer cells.

PubMed

Berrak, Özge; Akkoç, Yunus; Arısan, Elif Damla; Çoker-Gürkan, Ajda; Obakan-Yerlikaya, Pınar; Palavan-Ünsal, Narçin

2016-02-01

Bcl-2 protein has been contributed with number of genes which are involved in oncogenesis. Among the many targets of Bcl-2, NFκB have potential role in induction of cell cycle arrest. Curcumin has potential therapeutic effects against breast cancer through multiple signaling pathways. In this study, we investigated the role of curcumin in induction of cell cycle arrest via regulating of NFκB and polyamine biosynthesis in wt and Bcl-2+ MCF-7 cells. To examine the effect of curcumin on cell cycle regulatory proteins, PI3K/Akt, NFκB pathways and polyamine catabolism, we performed immunoblotting assay. In addition, cell cycle analysis was performed by flow cytometry. The results indicated that curcumin induced cell cycle arrest at G2/M phase by downregulation of cyclin B1 and Cdc2 and inhibited colony formation in MCF-7wt cells. However, Bcl-2 overexpression prevented the inhibition of cell cycle associated proteins after curcumin treatment. The combination of LY294002, PI3K inhibitor, and curcumin induced cell cycle arrest by decreasing CDK4, CDK2 and cyclin E2 in Bcl-2+ MCF-7 cells. Moreover, LY294002 further inhibited the phosphorylation of Akt in Bcl-2+ MCF-7 cells. Curcumin could suppress the nuclear transport of NFκB through decreasing the interaction of P-IκB-NFκB. The combination of wedelolactone, NFκB inhibitor, and curcumin acted different on SSAT expression in wt MCF-7 and Bcl-2+ MCF-7 cells. NFκB inhibition increased the SSAT after curcumin treatment in Bcl-2 overexpressed MCF-7 cells. Inhibition of NFκB activity as well as suppression of ROS generation with NAC resulted in the partial relief of cells from G2/M checkpoint after curcumin treatment in wt MCF-7 cells. In conclusion, the potential role of curcumin in induction of cell cycle arrest is related with NFκB-regulated polyamine biosynthesis. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Exacerbation of spontaneous autoimmune nephritis following regulatory T cell depletion in B cell lymphoma 2-interacting mediator knock-out mice.

PubMed

Wang, Y M; Zhang, G Y; Wang, Y; Hu, M; Zhou, J J; Sawyer, A; Cao, Q; Wang, Y; Zheng, G; Lee, V W S; Harris, D C H; Alexander, S I

2017-05-01

Regulatory T cells (T regs ) have been recognized as central mediators for maintaining peripheral tolerance and limiting autoimmune diseases. The loss of T regs or their function has been associated with exacerbation of autoimmune disease. However, the temporary loss of T regs in the chronic spontaneous disease model has not been investigated. In this study, we evaluated the role of T regs in a novel chronic spontaneous glomerulonephritis model of B cell lymphoma 2-interacting mediator (Bim) knock-out mice by transient depleting T regs . Bim is a pro-apoptotic member of the B cell lymphoma 2 (Bcl-2) family. Bim knock-out (Bim -/- ) mice fail to delete autoreactive T cells in thymus, leading to chronic spontaneous autoimmune kidney disease. We found that T reg depletion in Bim -/- mice exacerbated the kidney injury with increased proteinuria, impaired kidney function, weight loss and greater histological injury compared with wild-type mice. There was a significant increase in interstitial infiltrate of inflammatory cells, antibody deposition and tubular damage. Furthermore, the serum levels of cytokines interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17α, interferon (IFN)-γ and tumour necrosis factor (TNF)-α were increased significantly after T reg depletion in Bim -/- mice. This study demonstrates that transient depletion of T regs leads to enhanced self-reactive T effector cell function followed by exacerbation of kidney disease in the chronic spontaneous kidney disease model of Bim-deficient mice. © 2017 British Society for Immunology.

Lymphomagenic CARD11/BCL10/MALT1 signaling drives malignant B-cell proliferation via cooperative NF-κB and JNK activation.

PubMed

Knies, Nathalie; Alankus, Begüm; Weilemann, Andre; Tzankov, Alexandar; Brunner, Kristina; Ruff, Tanja; Kremer, Marcus; Keller, Ulrich B; Lenz, Georg; Ruland, Jürgen

2015-12-29

The aggressive activated B cell-like subtype of diffuse large B-cell lymphoma is characterized by aberrant B-cell receptor (BCR) signaling and constitutive nuclear factor kappa-B (NF-κB) activation, which is required for tumor cell survival. BCR-induced NF-κB activation requires caspase recruitment domain-containing protein 11 (CARD11), and CARD11 gain-of-function mutations are recurrently detected in human diffuse large B-cell lymphoma (DLBCL). To investigate the consequences of dysregulated CARD11 signaling in vivo, we generated mice that conditionally express the human DLBCL-derived CARD11(L225LI) mutant. Surprisingly, CARD11(L225LI) was sufficient to trigger aggressive B-cell lymphoproliferation, leading to early postnatal lethality. CARD11(L225LI) constitutively associated with B-cell CLL/lymphoma 10 (BCL10) and mucosa-associated lymphoid tissue lymphoma translocation gene 1 (MALT1) to simultaneously activate the NF-κB and c-Jun N-terminal kinase (JNK) signaling cascades. Genetic deficiencies of either BCL10 or MALT1 completely rescued the phenotype, and pharmacological inhibition of JNK was, similar to NF-κB blockage, toxic to autonomously proliferating CARD11(L225LI)-expressing B cells. Moreover, constitutive JNK activity was observed in primary human activated B cell-like (ABC)-DLBCL specimens, and human ABC-DLBCL cells were also sensitive to JNK inhibitors. Thus, our results demonstrate that enforced activation of CARD11/BCL10/MALT1 signaling is sufficient to drive transformed B-cell expansion in vivo and identify the JNK pathway as a therapeutic target for ABC-DLBCL.

Ascorbic Acid and Combination Chemotherapy in Treating Patients With Relapsed or Refractory Lymphoma

ClinicalTrials.gov

2018-03-23

High Grade B-Cell Lymphoma With MYC and BCL2 or BCL6 Rearrangements; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Lymphoma

(-)-Epigallocatechin-3-Gallate Modulates Spinal Cord Neuronal Degeneration by Enhancing Growth-Associated Protein 43, B-Cell Lymphoma 2, and Decreasing B-Cell Lymphoma 2-Associated X Protein Expression after Sciatic Nerve Crush Injury

PubMed Central

Al-Maghrebi, May; Rao, Muddanna S.; Khraishah, Haitham

2015-01-01

Abstract Our previous studies have established that (-)-epigallocatechin-3-gallate (EGCG) has both neuroprotective and -regenerative capacity after sciatic nerve injury. Moreover, this improvement was evident on the behavioral level. The aim of this study was to investigate the central effects of ECGC on spinal cord motor neurons after sciatic nerve injury. Our study showed that administering 50 mg/kg intraperitoneally i.p. of EGCG to sciatic nerve-injured rats improved their performance on different motor functions and mechanical hyperesthesia neurobehavioral tests. Histological analysis of spinal cords of EGCG-treated sciatic nerve-injured (CRUSH+ECGC) animals showed an increase in the number of neurons in the anterior horn, when compared to the naïve, sham, and saline-treated sciatic nerve-injured (CRUSH) control groups. Additionally, immunohistochemical study of spinal cord sections revealed that EGCG reduced the expression of glial fibrillary acidic protein and increased the expression of growth-associated protein 43, a marker of regenerating axons. Finally, EGCG reduced the ratio of B-cell lymphoma 2 (Bcl-2)-associated X protein/Bcl-2 and increased the expression of survivin gene. This study may shed some light on the future clinical use of EGCG and its constituents in the treatment of peripheral nerve injury. PMID:25025489

Endometrial Polyps and Benign Endometrial Hyperplasia Present Increased Prevalence of DNA Fragmentation Factors 40 and 45 (DFF40 and DFF45) Together With the Antiapoptotic B-Cell Lymphoma (Bcl-2) Protein Compared With Normal Human Endometria.

PubMed

Banas, Tomasz; Pitynski, Kazimierz; Mikos, Marcin; Cielecka-Kuszyk, Joanna

2017-09-13

DNA fragmentation factor 40 (DFF40) is a key executor of apoptosis. It localizes to the nucleus together with DNA fragmentation factor 45 (DFF45), which acts as a DFF40 inhibitor and chaperone. B-cell lymphoma (Bcl-2) protein is a proven antiapoptotic factor present in the cytoplasm. In this study, we aimed to investigate DFF40, DFF45, and Bcl-2 immunoexpression in endometrial polyps (EPs) and benign endometrial hyperplasia (BEH) tissue compared with that in normal proliferative endometrium (NPE) and normal secretory endometrium (NSE) as well as normal post menopausal endometrium (NAE). This study used archived samples from 65 and 62 cases of EPs and BEH, respectively. The control group consisted of 52 NPE, 54 NSE, and 54 NAE specimens. Immunohistochemistry was used to detect DFF40, DFF45, and Bcl-2. DFF40, DFF45, and Bcl-2 were more highly expressed in the glandular layer of EPs and BEH compared with the stroma, and this was not influenced by menopausal status. Both glandular and stromal expression of DFF40, DFF45, and Bcl-2 were significantly higher in EPs compared with NPE, NSE, and NAE. Glandular BEH tissue showed significantly higher DFF40, DFF45, and Bcl-2 expression than in NPE, NSE, and NAE. No differences in the glandular expression of DFF40, DFF45, and Bcl-2 were observed between EP and BEH tissues, while Bcl-2 stromal expression in BEH was significantly lower than in EPs. Glandular, menopause-independent DFF40, DFF45, and Bcl-2 overexpression may play an important role in the pathogenesis of EPs and BEH.

Non-endometrioid and high-grade endometrioid endometrial cancers show DNA fragmentation factor 40 (DFF40) and B-cell lymphoma 2 protein (BCL2) underexpression, which predicts disease-free and overall survival, but not DNA fragmentation factor 45 (DFF45) underexpression.

PubMed

Banas, Tomasz; Pitynski, Kazimierz; Okon, Krzysztof; Winiarska, Aleksandra

2018-04-13

The expression of DNA fragmentation factor 45 (DFF45) and B-cell lymphoma 2 (BCL2) in glands of the normal human endometrium is related to phases of the menstrual cycle and decreases after menopause, whereas the expression of DNA fragmentation factor 40 (DFF40) is stable. Moreover, DF45, BCL2 and DFF40 underexpression has been reported in numerous malignancies, including uterine leiomyosarcomas. In this study, we aimed to investigate DFF45, BCL2 and DFF40 expression in endometrioid and non-endometrioid types of endometrial cancers (ECs). We also evaluated the correlations between DFF45, BCL2 and DFF40 expression levels and clinicopathological parameters and determined the value of these three proteins as prognostic markers of disease-free survival (DFS) and overall survival (OS). Immunohistochemistry was performed to evaluate DFF45, BCL2 and DFF40 expression in 342 cases of ECs. Student's t-test, the Mann-Whitney U-test, and the chi-squared test were used for the statistical analyses as appropriate. The Cox-Mantel test, Cox's proportional hazard model, and relative risk analyses were used to evaluate associations between DFF40, DFF45, and BCL2 expression and clinicopathological characteristics. DFF40 and BCL2, but not DFF45, were significantly underexpressed in non-endometrioid and high-grade endometrioid ECs compared with low- and moderate-grade endometrioid ECs. Women with DFF40- and BCL2-negative tumors had higher risks of disease recurrence, lymph node involvement, lympho-vascular space infiltration, and deep myometrial invasion compared with women with DFF40- and BCL2-positive tumors. Additionally, women with DFF40- and BCL2-negative tumors had significantly lower OS and DFS than women with DFF40- and BCL2-positive tumors. A multivariable analysis of the model, including the clinicopathological characteristics and immunohistochemical results, showed that negative BCL2 expression, lymph node involvement, and high-stage and high-grade disease were independent

B1-induced caspase-independent apoptosis in MCF-7 cells is mediated by down-regulation of Bcl-2 via p53 binding to P2 promoter TATA box

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang Xin; Xu Ke; Xu Yufang

The Bcl-2 family contains a panel of proteins which are conserved regulators of apoptosis in mammalian cells, like the anti-apoptotic protein Bcl-2. According to its significant role in altering susceptibility to apoptosis, the deciphering of the mechanism of Bcl-2 expression modulation may be crucial for identifying therapeutics strategies for cancer. Treatment with naphthalimide-based DNA intercalators, including M2-A and R16, generally leads to a decrease in Bcl-2 intracellular amounts. Whereas the interest for these chemotherapeutics is accompanied by advances in the fundamental understanding of their anticancer properties, the molecular mechanism underlying changes in Bcl-2 expression remains poorly understood. We report heremore » that p53 contributes to Bcl-2 down-regulation induced by B1, a novel naphthalimide-based DNA intercalating agent. Indeed, the decrease in Bcl-2 protein levels observed during B1-induced apoptosis was correlated to the decrease in mRNA levels, as a result of the inhibition of Bcl-2 transcription and promoter activity. In this context, we evaluated p53 contribution in the Bcl-2 transcriptional down-regulation. We found a significant increase of p53 binding to P{sub 2} promoter TATA box in MCF7 cells by chromatin immunoprecipitation. These data suggest that B1-induced caspase-independent apoptosis in MCF-7 cells is associated with the activation of p53 and the down-regulation of Bcl-2. Our study strengthens the links between p53 and Bcl-2 at a transcriptional level, upon naphthalimide-based DNA intercalator treatment. - Research Highlights: > B1 induced apoptosis in MCF-7 cells, following a transcriptional decrease in Bcl-2. > B1 treatment triggered p53 activation and leads to a p53-dependent down-regulation of Bcl-2. > B1 induced significant increase of p53 binding to Bcl-2 P{sub 2} promoter TATA box.« less

Control of mitochondrial physiology and cell death by the Bcl-2 family proteins Bax and Bok.

PubMed

D'Orsi, Beatrice; Mateyka, Julia; Prehn, Jochen H M

2017-10-01

Neuronal cell death is often triggered by events that involve intracellular increases in Ca 2+ . Under resting conditions, the intracellular Ca 2+ concentration is tightly controlled by a number of extrusion and sequestering mechanisms involving the plasma membrane, mitochondria, and ER. These mechanisms act to prevent a disruption of neuronal ion homeostasis. As these processes require ATP, excessive Ca 2+ overloading may cause energy depletion, mitochondrial dysfunction, and may eventually lead to Ca 2+ -dependent cell death. Excessive Ca 2+ entry though glutamate receptors (excitotoxicity) has been implicated in several neurologic and chronic neurodegenerative diseases, including ischemic stroke, epilepsy, and Alzheimer's disease. Recent evidence has revealed that excitotoxic cell death is regulated by the B-cell lymphoma-2 (Bcl-2) family of proteins. Bcl-2 proteins, comprising of both pro-apoptotic and anti-apoptotic members, have been shown to not only mediate the intrinsic apoptosis pathway by controlling mitochondrial outer membrane (MOM) integrity, but to also control neuronal Ca 2+ homeostasis and energetics. In this review, the role of Bcl-2 family proteins in the regulation of apoptosis, their expression in the central nervous system and how they control Ca 2+ -dependent neuronal injury are summarized. We review the current knowledge on Bcl-2 family proteins in the regulation of mitochondrial function and bioenergetics, including the fusion and fission machinery, and their role in Ca 2+ homeostasis regulation at the mitochondria and ER. Specifically, we discuss how the 'pro-apoptotic' Bcl-2 family proteins, Bax and Bok, physiologically expressed in the nervous system, regulate such 'non-apoptotic/daytime' functions. Copyright © 2017 Elsevier Ltd. All rights reserved.

FADD and the NF-κB family member Bcl-3 regulate complementary pathways to control T-cell survival and proliferation

PubMed Central

Rangelova, Svetla; Kirschnek, Susanne; Strasser, Andreas; Häcker, Georg

2008-01-01

Fas-associated protein with death domain/mediator of receptor induced toxicity (FADD/MORT1) was first described as a transducer of death receptor signalling but was later recognized also to be important for proliferation of T cells. B-cell lymphoma 3 (Bcl-3) is a relatively little understood member of the nuclear factor (NF)-κB family of transcription factors. We recently found that Bcl-3 is up-regulated in T cells from mice where FADD function is blocked by a dominant negative transgene (FADD-DN). To understand the importance of this, we generated FADD-DN/bcl-3−/− mice. Here, we report that T cells from these mice show massive cell death and severely reduced proliferation in response to T-cell receptor (TCR) stimulation in vitro. Transgenic co-expression of Bcl-2 (FADD-DN/bcl-3−/−/vav-bcl-2 mice) rescued the survival but not the proliferation of T cells. FADD-DN/bcl-3−/− mice had normal thymocyte numbers but reduced numbers of peripheral T cells despite an increase in cycling T cells in vivo. However, activation of the classical NF-κB and extracellular regulated kinase (ERK) pathways and expression of interleukin (IL)-2 mRNA upon stimulation were normal in T cells from FADD-DN/bcl-3−/− mice. These data suggest that FADD and Bcl-3 regulate separate pathways that both contribute to survival and proliferation in mouse T cells. PMID:18557791

Comparative biodistributions and dosimetry of [¹⁷⁷Lu]DOTA-anti-bcl-2-PNA-Tyr³-octreotate and [¹⁷⁷Lu]DOTA-Tyr³-octreotate in a mouse model of B-cell lymphoma/leukemia.

PubMed

Balkin, Ethan R; Liu, Dijie; Jia, Fang; Ruthengael, Varyanna C; Shaffer, Suzanne M; Miller, William H; Lewis, Michael R

2014-01-01

The B-cell lymphoma/leukemia-2 (bcl-2) proto-oncogene in non-Hodgkin's lymphoma (NHL) is a dominant inhibitor of apoptosis. We developed a (177)Lu-labeled bcl-2 antisense peptide nucleic acid (PNA)-peptide conjugate designed for dual modality NHL therapy, consisting of a radiopharmaceutical capable of simultaneously down-regulating apoptotic resistance and delivering cytotoxic internally emitted radiation. DOTA-anti-bcl-2-Tyr(3)-octreotate was synthesized, labeled with (177)Lu, and purified using RP-HPLC. The PNA-peptide conjugate was evaluated in Mec-1 NHL-bearing mice and compared to [(177)Lu]DOTA-Tyr(3)-octreotate in biodistribution and excretion studies. These data were then used to generate in vivo dosimetry models. The PNA-peptide conjugate was readily prepared and radiolabeled in high yield and radiochemical purity. An in vivo blocking study determined that administration of 50 μg of non-radioactive PNA-peptide was the optimal mass for maximum delivery to the tumor. Based on that result, a dosing regimen of (177)Lu-PNA-peptide, for radiologic effect, followed by the optimal mass of non-radioactive compound, for antisense effect, was designed. Using that dosing regimen, biodistribution of the PNA-peptide showed uptake in the tumor with minimal washout over a 4-day period. Uptakes in receptor-positive normal organs were low and displayed nearly complete washout by 24h. Dosimetry models showed that the tumor absorbed dose of the PNA-peptide conjugate was approximately twice that of the peptide-only conjugate. Biodistribution data showed specific tumor targeting of the (177)Lu-labeled PNA-peptide compound with minimal receptor-positive normal tissue uptake when compared to [(177)Lu]DOTA-Tyr(3)-octreotate. In vivo dosimetry models predicted a more favorable tumor absorbed dose from [(177)Lu]DOTA-anti-bcl-2-Tyr(3)-octreotate. © 2013.

A dual role for the anti-apoptotic Bcl-2 protein in cancer: mitochondria versus endoplasmic reticulum.

PubMed

Akl, Haidar; Vervloessem, Tamara; Kiviluoto, Santeri; Bittremieux, Mart; Parys, Jan B; De Smedt, Humbert; Bultynck, Geert

2014-10-01

Anti-apoptotic Bcl-2 contributes to cancer formation and progression by promoting the survival of altered cells. Hence, it is a prime target for novel specific anti-cancer therapeutics. In addition to its canonical anti-apoptotic role, Bcl-2 has an inhibitory effect on cell-cycle progression. Bcl-2 acts at two different intracellular compartments, the mitochondria and the endoplasmic reticulum (ER). At the mitochondria, Bcl-2 via its hydrophobic cleft scaffolds the Bcl-2-homology (BH) domain 3 (BH3) of pro-apoptotic Bcl-2-family members. Small molecules (like BH3 mimetics) can disrupt this interaction, resulting in apoptotic cell death in cancer cells. At the ER, Bcl-2 modulates Ca(2+) signaling, thereby promoting proliferation while increasing resistance to apoptosis. Bcl-2 at the ER acts via its N-terminal BH4 domain, which directly binds and inhibits the inositol 1,4,5-trisphosphate receptor (IP3R), the main intracellular Ca(2+)-release channel. Tools targeting the BH4 domain of Bcl-2 reverse Bcl-2's inhibitory action on IP3Rs and trigger pro-apoptotic Ca(2+) signaling in cancer B-cells, including chronic lymphocytic leukemia (CLL) cells and diffuse large B-cell lymphoma (DLBCL) cells. The sensitivity of DLBCL cells to BH4-domain targeting tools strongly correlated with the expression levels of the IP3R2 channel, the IP3R isoform with the highest affinity for IP3. Interestingly, bio-informatic analysis of a database of primary CLL patient cells also revealed a transcriptional upregulation of IP3R2. Finally, this review proposes a model, in which cancer cell survival depends on Bcl-2 at the mitochondria and/or the ER. This dependence likely will have an impact on their responses to BH3-mimetic drugs and BH4-domain targeting tools. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau. Copyright © 2014 Elsevier B.V. All rights

Trastuzumab down-regulates Bcl-2 expression and potentiates apoptosis induction by Bcl-2/Bcl-XL bispecific antisense oligonucleotides in HER-2 gene--amplified breast cancer cells.

PubMed

Milella, Michele; Trisciuoglio, Daniela; Bruno, Tiziana; Ciuffreda, Ludovica; Mottolese, Marcella; Cianciulli, Anna; Cognetti, Francesco; Zangemeister-Wittke, Uwe; Del Bufalo, Donatella; Zupi, Gabriella

2004-11-15

To investigate the possible existence of an antiapoptotic cross-talk between HER-2 and antiapoptotic Bcl-2 family members. Bcl-2 and Bcl-XL expression and apoptosis induction were analyzed in HER-2 gene-amplified (BT474) and nonamplified (ZR 75-1) breast cancer cell lines exposed to trastuzumab, alone or in combination with either Bcl-2/Bcl-XL bispecific antisense oligonucleotides (AS-4625) or the small-molecule Bcl-2 antagonist HA14-1. In addition to HER-2 and epidermal growth factor receptor, trastuzumab down-regulated Bcl-2, but not Bcl-XL, protein, and mRNA expression in BT474 cells. Interestingly, trastuzumab-induced down-regulation of HER-2 and Bcl-2 was also observed in three of five and two of three breast cancer patients undergoing trastuzumab treatment, respectively. Despite Bcl-2 down-regulation, however, trastuzumab only marginally increased the rate of apoptosis (7.3 +/- 3.5%). We therefore investigated whether a combination of AS-4625 and trastuzumab might increase proapoptotic efficiency. AS-4625 treatment of BT474 cells decreased both Bcl-2 and Bcl-XL expression, resulting in a 21 +/- 7% net apoptosis induction; the combination of AS-4625 followed by trastuzumab resulted in a significantly stronger induction of apoptosis (37 +/- 6%, P <0.01) that was not observed with the reverse treatment sequence (trastuzumab followed by AS-4625). Similar results were obtained with the Bcl-2 antagonist HA14-1; indeed, exposure of BT474 cells to HA14-1 followed by trastuzumab resulted in a striking proapoptotic synergism (combination index=0.58 +/- 0.18), as assessed by isobologram analysis. Altogether our findings suggest that combined targeting of HER-2 and Bcl-2 may represent a novel, rational approach to more effective breast cancer therapy.

Bcl-2△21 and Ac-DEVD-CHO Inhibit Death of Wheat Microspores

PubMed Central

Sinha, Rakesh K.; Pospíšil, Pavel; Maheshwari, Priti; Eudes, François

2016-01-01

Microspore cell death and low green plant production efficiency are an integral obstacle in the development of doubled haploid production in wheat. The aim of the current study was to determine the effect of anti-apoptotic recombinant human B-cell lymphoma-2 (Bcl-2△21) and caspase-3-inhibitor (Ac-DEVD-CHO) in microspore cell death in bread wheat cultivars AC Fielder and AC Andrew. Induction medium containing Bcl-2△21 and Ac-DEVD-CHO yielded a significantly higher number of viable microspores, embryo-like structures and total green plants in wheat cultivars AC Fielder and AC Andrew. Total peroxidase activity was lower in Bcl-2△21 treated microspore cultures at 96 h of treatment compared to control and Ac-DEVD-CHO. Electron paramagnetic resonance study of total microspore protein showed a different scavenging activity for Bcl-2△21 and Ac-DEVD-CHO. Bcl-2△21 scavenged approximately 50% hydroxyl radical (HO•) formed, whereas Ac-DEVD-CHO scavenged approximately 20% of HO•. Conversely, reduced caspase-3-like activities were detected in the presence of Bcl-2△21 and Ac-DEVD-CHO, supporting the involvement of Bcl-2△21 and Ac-DEVD-CHO in increasing microspore viability by reducing oxidative stress and caspase-3-like activity. Our results indicate that Bcl-2△21 and Ac-DEVD-CHO protects cells from cell death following different pathways. Bcl-2△21 prevents cell damage by detoxifying HO• and suppressing caspase-3-like activity, while Ac-DEVD-CHO inhibits the cell death pathways by modulating caspase-like activity. PMID:28082995

Targeting Non-proteolytic Protein Ubiquitination for the Treatment of Diffuse Large B Cell Lymphoma.

PubMed

Yang, Yibin; Kelly, Priscilla; Shaffer, Arthur L; Schmitz, Roland; Yoo, Hee Min; Liu, Xinyue; Huang, Da Wei; Webster, Daniel; Young, Ryan M; Nakagawa, Masao; Ceribelli, Michele; Wright, George W; Yang, Yandan; Zhao, Hong; Yu, Xin; Xu, Weihong; Chan, Wing C; Jaffe, Elaine S; Gascoyne, Randy D; Campo, Elias; Rosenwald, Andreas; Ott, German; Delabie, Jan; Rimsza, Lisa; Staudt, Louis M

2016-04-11

Chronic active B cell receptor (BCR) signaling, a hallmark of the activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), engages the CARD11-MALT1-BCL10 (CBM) adapter complex to activate IκB kinase (IKK) and the classical NF-κB pathway. Here we show that the CBM complex includes the E3 ubiquitin ligases cIAP1 and cIAP2, which are essential mediators of BCR-dependent NF-κB activity in ABC DLBCL. cIAP1/2 attach K63-linked polyubiquitin chains on themselves and on BCL10, resulting in the recruitment of IKK and the linear ubiquitin chain ligase LUBAC, which is essential for IKK activation. SMAC mimetics target cIAP1/2 for destruction, and consequently suppress NF-κB and selectively kill BCR-dependent ABC DLBCL lines, supporting their clinical evaluation in patients with ABC DLBCL. Copyright © 2016 Elsevier Inc. All rights reserved.

Gossypol inhibits phosphorylation of Bcl-2 in human leukemia HL-60 cells.

PubMed

Huang, Li-heng; Hu, Jia-qi; Tao, Wei-qun; Li, Yuan-hong; Li, Guan-ming; Xie, Pei-yi; Liu, Xiao-shan; Jiang, Jikai

2010-10-25

Gossypol is an attractive therapeutic anti-tumor agent as an apoptosis inducer and is being evaluated in preclinical tests. However, the molecular mechanisms underlying apoptosis induction by gossypol in malignant cells have not been completely enunciated. Here we investigate the alterations of Bcl-2/Bcl-xL/Mcl-1 protein levels and Bcl-2 phosphorylation in gossypol-induced apoptosis in human leukemia HL-60 cells. We found that gossypol treatment inhibited cell growth and induced apoptosis in HL-60 cells. Bcl-2/Bcl-xL/Mcl-1 protein levels were slightly reduced and phosphorylation of Bcl-2 at threonine 56 (phospho T56) was not altered. However, phosphorylation of Bcl-2 at serine 70 (phospho S70) was strikingly down-regulated in gossypol-exposed cells. This reduction was found to be not only in both dose- and time-dependent fashion but also obviated by phorbol l2,13-dibutyrate (PDBu), an activator of protein kinase C (PKC). In addition, pre-treatment of PDBu partially prevented gossypol-induced apoptosis in HL-60 cells. Collectively, gossypol treatment can reduce phosphorylation of Bcl-2 at serine 70 in leukemia HL-60 cells and gossypol may be a promising therapeutical candidate for leukemia patients especially expressing phosphorylated Bcl-2 at Ser70. Copyright 2010 Elsevier B.V. All rights reserved.

Systems modeling accurately predicts responses to genotoxic agents and their synergism with BCL-2 inhibitors in triple negative breast cancer cells.

PubMed

Lucantoni, Federico; Lindner, Andreas U; O'Donovan, Norma; Düssmann, Heiko; Prehn, Jochen H M

2018-01-19

Triple negative breast cancer (TNBC) is an aggressive form of breast cancer which accounts for 15-20% of this disease and is currently treated with genotoxic chemotherapy. The BCL2 (B-cell lymphoma 2) family of proteins controls the process of mitochondrial outer membrane permeabilization (MOMP), which is required for the activation of the mitochondrial apoptosis pathway in response to genotoxic agents. We previously developed a deterministic systems model of BCL2 protein interactions, DR_MOMP that calculates the sensitivity of cells to undergo mitochondrial apoptosis. Here we determined whether DR_MOMP predicts responses of TNBC cells to genotoxic agents and the re-sensitization of resistant cells by BCL2 inhibitors. Using absolute protein levels of BAX, BAK, BCL2, BCL(X)L and MCL1 as input for DR_MOMP, we found a strong correlation between model predictions and responses of a panel of TNBC cells to 24 and 48 h cisplatin (R 2  = 0.96 and 0.95, respectively) and paclitaxel treatments (R 2  = 0.94 and 0.95, respectively). This outperformed single protein correlations (best performer BCL(X)L with R 2 of 0.69 and 0.50 for cisplatin and paclitaxel treatments, respectively) and BCL2 proteins ratio (R 2 of 0.50 for cisplatin and 0.49 for paclitaxel). Next we performed synergy studies using the BCL2 selective antagonist Venetoclax /ABT199, the BCL(X)L selective antagonist WEHI-539, or the MCL1 selective antagonist A-1210477 in combination with cisplatin. In silico predictions by DR_MOMP revealed substantial differences in treatment responses of BCL(X)L, BCL2 or MCL1 inhibitors combinations with cisplatin that were successfully validated in cell lines. Our findings provide evidence that DR_MOMP predicts responses of TNBC cells to genotoxic therapy, and can aid in the choice of the optimal BCL2 protein antagonist for combination treatments of resistant cells.

Acidosis Promotes Bcl-2 Family-mediated Evasion of Apoptosis

PubMed Central

Ryder, Christopher; McColl, Karen; Zhong, Fei; Distelhorst, Clark W.

2012-01-01

Acidosis arises in solid and lymphoid malignancies secondary to altered nutrient supply and utilization. Tumor acidosis correlates with therapeutic resistance, although the mechanism behind this effect is not fully understood. Here we show that incubation of lymphoma cell lines in acidic conditions (pH 6.5) blocks apoptosis induced by multiple cytotoxic metabolic stresses, including deprivation of glucose or glutamine and treatment with dexamethasone. We sought to examine the role of the Bcl-2 family of apoptosis regulators in this process. Interestingly, we found that acidic culture causes elevation of both Bcl-2 and Bcl-xL, while also attenuating glutamine starvation-induced elevation of p53-up-regulated modulator of apoptosis (PUMA) and Bim. We confirmed with knockdown studies that these shifts direct survival decisions during starvation and acidosis. Importantly, the promotion of a high anti- to pro-apoptotic Bcl-2 family member ratio by acidosis renders cells exquisitely sensitive to the Bcl-2/Bcl-xL antagonist ABT-737, suggesting that acidosis causes Bcl-2 family dependence. This dependence appears to be mediated, in part, by the acid-sensing G protein-coupled receptor, GPR65, via a MEK/ERK pathway. PMID:22685289

Hypoxia-response plasmid vector producing bcl-2 shRNA enhances the apoptotic cell death of mouse rectum carcinoma.

PubMed

Fujioka, Takashi; Matsunaga, Naoya; Okazaki, Hiroyuki; Koyanagi, Satoru; Ohdo, Shigehiro

2010-01-01

Hypoxia-induced gene expression frequently occurs in malignant solid tumors because they often have hypoxic areas in which circulation is compromised due to structurally disorganized blood vessels. Hypoxia-response elements (HREs) are responsible for activating gene transcription in response to hypoxia. In this study, we constructed a hypoxia-response plasmid vector producing short hairpin RNA (shRNA) against B-cell leukemia/lymphoma-2 (bcl-2), an anti-apoptotic factor. The hypoxia-response promoter was made by inserting tandem repeats of HREs upstream of cytomegalovirus (CMV) promoter (HRE-CMV). HRE-CMV shbcl-2 vector consisted of bcl-2 shRNA under the control of HRE-CMV promoter. In hypoxic mouse rectum carcinoma cells (colon-26), the production of bcl-2 shRNA driven by HRE-CMV promoter was approximately 2-fold greater than that driven by CMV promoter. A single intratumoral (i.t.) injection of 40 microg HRE-CMV shbcl-2 to colon-26 tumor-bearing mice caused apoptotic cell death, and repetitive treatment with HRE-CMV shbcl-2 (40 microg/mouse, i.t.) also significantly suppressed the growth of colon-26 tumor cells implanted in mice. Apoptotic and anti-tumor effects were not observed in tumor-bearing mice treated with CMV shbcl-2. These results reveal the ability of HRE-CMV shbcl-2 vector to suppress the expression of bcl-2 in hypoxic tumor cells and suggest the usefulness of our constructed hypoxia-response plasmid vector to treat malignant tumors. [Supplementary Figures: available only at http://dx.doi.org/10.1254/jphs.10054FP].

BCL-2 Modifying Factor (BMF) Is a Central Regulator of Anoikis in Human Intestinal Epithelial Cells*

PubMed Central

Hausmann, Martin; Leucht, Katharina; Ploner, Christian; Kiessling, Stephan; Villunger, Andreas; Becker, Helen; Hofmann, Claudia; Falk, Werner; Krebs, Michaela; Kellermeier, Silvia; Fried, Michael; Schölmerich, Jürgen; Obermeier, Florian; Rogler, Gerhard

2011-01-01

BCL-2 modifying factor (BMF) is a sentinel considered to register damage at the cytoskeleton and to convey a death signal to B-cell lymphoma 2. B-cell lymphoma 2 is neutralized by BMF and thereby facilitates cytochrome C release from mitochondria. We investigated the role of BMF for intestinal epithelial cell (IEC) homeostasis. Acute colitis was induced in Bmf-deficient mice (Bmf−/−) with dextran sulfate sodium. Colonic crypt length in Bmf−/− mice was significantly increased as compared with WT mice. Dextran sulfate sodium induced less signs of colitis in Bmf−/− mice, as weight loss was reduced compared with the WT. Primary human IEC exhibited increased BMF in the extrusion zone. Quantitative PCR showed a significant up-regulation of BMF expression after initiation of anoikis in primary human IEC. BMF was found on mitochondria during anoikis, as demonstrated by Western blot analysis. RNAi mediated knockdown of BMF reduced the number of apoptotic cells and led to reduced caspase 3 activity. A significant increase in phospho-AKT was determined after RNAi treatment. BMF knockdown supports survival of IEC. BMF is induced in human IEC by the loss of cell attachment and is likely to play an important role in the regulation of IEC survival. PMID:21673109

The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development.

PubMed

Ortega-Molina, Ana; Boss, Isaac W; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A; Gascoyne, Randy D; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M; Wendel, Hans-Guido

2015-10-01

The gene encoding the lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma and diffuse large B cell lymphoma; however, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center involution and impedes B cell differentiation and class switch recombination. Integrative genomic analyses indicate that KMT2D affects methylation of lysine 4 on histone H3 (H3K4) and expression of a set of genes, including those in the CD40, JAK-STAT, Toll-like receptor and B cell receptor signaling pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3 and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell-activating pathways.

The histone lysine methyltransferase KMT2D sustains a gene expression program that represses B cell lymphoma development

PubMed Central

Ortega-Molina, Ana; Boss, Isaac W.; Canela, Andres; Pan, Heng; Jiang, Yanwen; Zhao, Chunying; Jiang, Man; Hu, Deqing; Agirre, Xabier; Niesvizky, Itamar; Lee, Ji-Eun; Chen, Hua-Tang; Ennishi, Daisuke; Scott, David W.; Mottok, Anja; Hother, Christoffer; Liu, Shichong; Cao, Xing-Jun; Tam, Wayne; Shaknovich, Rita; Garcia, Benjamin A.; Gascoyne, Randy D.; Ge, Kai; Shilatifard, Ali; Elemento, Olivier; Nussenzweig, Andre; Melnick, Ari M.; Wendel, Hans-Guido

2015-01-01

The lysine-specific histone methyltransferase KMT2D has emerged as one of the most frequently mutated genes in follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL). However, the biological consequences of KMT2D mutations on lymphoma development are not known. Here we show that KMT2D functions as a bona fide tumor suppressor and that its genetic ablation in B cells promotes lymphoma development in mice. KMT2D deficiency also delays germinal center (GC) involution, impedes B cell differentiation and class switch recombination (CSR). Integrative genomic analyses indicate that KMT2D affects H3K4 methylation and expression of a specific set of genes including those in the CD40, JAK-STAT, Toll-like receptor, and B cell receptor pathways. Notably, other KMT2D target genes include frequently mutated tumor suppressor genes such as TNFAIP3, SOCS3, and TNFRSF14. Therefore, KMT2D mutations may promote malignant outgrowth by perturbing the expression of tumor suppressor genes that control B cell activating pathways. PMID:26366710

Signet-ring cell lymphoma: clinicopathologic, immunohistochemical, and fluorescence in situ hybridization studies of 7 cases.

PubMed

Zhang, Shanxiang; Sun, Jihong; Fang, Yanan; Nassiri, Mehdi; Liu, Lanting; Zhou, Jiehao; Stohler, Ryan; Choi, Haki; Vance, Gail H

2017-02-01

Signet-ring cell lymphoma (SRCL) is a rare morphologic variant of non-Hodgkin lymphoma. Although it was initially reported as a rare morphologic variant of follicular lymphoma (FL), SRCL has to date been described in most types of non-Hodgkin lymphoma, mostly as single-case reports. To study SRCL systematically by immunohistochemical stains and fluorescent in situ hybridization analyses. Seven SRCL cases were stained for CD3, CD5, CD20, PAX-5, CD10, CD21, CD23, cyclin D1, BCL2, BCL6, Ki-67, and MUM-1, and were analyzed by fluorescent in situ hybridization for BCL2, BCL6, MYC, and MALT1 rearrangements. Clinical information and patient outcome were reviewed in all patients. The patients were 3 women and 3 men, ranging in age from 31 to 75 years (average 60.3 years). The lesions involved lymph nodes, tonsil, parotid gland, soft tissue, and breast. There were 4 FLs, 1 diffuse large B-cell lymphoma (DLBCL), 1 DLBCL with FL, and 1 DLBCL with marginal zone lymphoma. All cases had typical signet-ring cell morphology. They were positive for CD20 and BCL-2, and had low-to-intermediate Ki-67 proliferation index (10%-40%) except in the parotid DLBCL with FL (70%). BCL-6 was detected in all but 1 FL (6/7). Fluorescent in situ hybridization detected IGH/BCL2 translocation in 1 FL, increased BCL6 copy number in another FL, BCL6 rearrangement, and increased copy number of MYC and MALT1 in the DLBCL with marginal zone lymphoma. The FL with signet-ring cell morphology (1/5) tends to lack IGH/BCL2 translocation, and an extended immunohistochemical study is recommended for correct diagnosis and classification of SRCL. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of celecoxib on cell apoptosis and Fas, FasL and Bcl-2 expression in a BGC-823 human gastric cancer cell line.

PubMed

Li, Qian; Peng, Jie; Liu, Ting; Zhang, Guiying

2017-09-01

Fas, which is an apoptotic-related protein, has an important role in cell apoptosis. Fas ligand (FasL) binds to Fas and activates apoptosis signal transduction. We previously demonstrated that the efficiency of celecoxib inhibited the proliferation and apoptosis of HT-29 colon cancer cell line. The BGC823 cell line was used as an experimental model to evaluate the potential role of celecoxib on gastric cancer cell apoptosis. Inhibitory effects of celecoxib on cell viability were determined by MTT assay. Cell apoptosis was evaluated by flow cytometric analysis and laser confocal microscopy. The results of the present study demonstrated that celecoxib inhibited the viability of BGC823 cells in a concentration- and time-dependent manner. Furthermore, the effect of BGC823 cells apoptosis was increased in a concentration-dependent manner. Western blotting was used to determine the protein expression levels of Fas, FasL, and B-cell lymphoma-2 (Bcl-2). During the celecoxib-induced apoptosis of BGC823 cells, celecoxib upregulated Fas expression and downregulated FasL and Bcl-2 expression in a concentration-dependent manner. These results suggest that celecoxib inhibited the growth and induced apoptosis of BGC823 gastric cancer cells by regulating the protein expression of Fas, FasL and Bcl-2.

Endogenous association of Bim BH3-only protein with Mcl-1, Bcl-xL and Bcl-2 on mitochondria in human B cells.

PubMed

Gomez-Bougie, Patricia; Bataille, Régis; Amiot, Martine

2005-03-01

Bim is an essential regulator of lymphoid system homeostasis and appears essential for B cell apoptosis induction. The mechanism by which Bim isoforms are held in an inactive form remains poorly documented in normal B cells. In the current study, we demonstrated that in normal tonsil B cells the three major Bim isoforms are strongly associated with the anti-apoptotic Bcl-2 family members Mcl-1, Bcl-2 and Bcl-x(L). On the other hand, only a weak association of BimEL and L with the dynein LC8 chain has been found. In addition, there is no free Bim in normal B cells. Moreover, subcellular fractionation demonstrated that Bim and the anti-apoptotic counterparts are localized preferentially in the mitochondria-rich fraction. The fact that most Bim was found in this fraction supports the hypothesis that it is sequestered by anti-apoptotic molecules in mitochondria where its pro-apoptotic activity is controlled. Of interest, BimS is essentially complexed to Mcl-1 and the Mcl-1/Bim complex is the most abundant among the three types of complexes. This supports the idea that this complex is critical for the control of B cell death. In conclusion, these results favor a model in which Bim release from anti-apoptotic proteins is a critical event for initiation of apoptosis.

Inhibition of ZEB1 by miR-200 characterizes Helicobacter pylori-positive gastric diffuse large B-cell lymphoma with a less aggressive behavior.

PubMed

Huang, Wei-Ting; Kuo, Sung-Hsin; Cheng, Ann-Lii; Lin, Chung-Wu

2014-08-01

Primary gastric diffuse large B-cell lymphomas may or may not have a concurrent component of mucosa-associated lymphoid tissue lymphoma. Diffuse large B-cell lymphoma/mucosa-associated lymphoid tissue lymphomas are often associated with Helicobacter pylori (H. pylori) infection, suggesting that the large cells are transformed from mucosa-associated lymphoid tissue lymphomas. In contrast, only limited data are available on the clinical and molecular features of pure gastric diffuse large B-cell lymphomas. In 102 pure gastric diffuse large B-cell lymphomas, we found H. pylori infection in 53% of the cases. H. pylori-positive gastric diffuse large B-cell lymphomas were more likely to present at an earlier stage (73% vs 52% at stage I/II, P=0.03), to achieve complete remission (75% vs 43%, P=0.001), and had a better 5-year disease-free survival rate (73% vs 29%, P<0.001) than H. pylori-negative gastric diffuse large B-cell lymphomas. Through genome-wide expression profiles of both miRNAs and mRNAs in nine H. pylori-positive and nine H. pylori-negative gastric diffuse large B-cell lymphomas, we identified inhibition of ZEB1 (zinc-finger E-box-binding homeobox 1) by miR-200 in H. pylori-positive gastric diffuse large B-cell lymphomas. ZEB1, a transcription factor for marginal zone B cells, can suppress BCL6, the master transcription factor for germinal center B cells. In 30 H. pylori-positive and 30 H. pylori-negative gastric diffuse large B-cell lymphomas, we confirmed that H. pylori-positive gastric diffuse large B-cell lymphomas had higher levels of miR-200 by qRT-PCR, and lower levels of ZEB1 and higher levels of BCL6 using immunohistochemistry. As BCL6 is a known predictor of a better prognosis in gastric diffuse large B-cell lymphomas, our data demonstrate that inhibition of ZEB1 by miR-200, with secondary increase in BCL6, is a molecular event that characterizes H. pylori-positive gastric diffuse large B-cell lymphomas with a less aggressive behavior.

The regulatory BCL2 promoter polymorphism (-938C>A) is associated with relapse and survival of patients with oropharyngeal squamous cell carcinoma.

PubMed

Lehnerdt, G F; Franz, P; Bankfalvi, A; Grehl, S; Kelava, A; Nückel, H; Lang, S; Schmid, K W; Siffert, W; Bachmann, H S

2009-06-01

Expression of the antiapoptotic and antiproliferative protein B-cell lymphoma 2 (Bcl-2) has been repeatedly shown to be associated with better locoregional control and patients' survival in oropharyngeal squamous cell carcinoma (OSCC). A regulatory (-938C>A) single-nucleotide polymorphism (SNP) in the inhibitory P2 BCL2 gene promoter generates significantly different BCL2 promoter activities and has been associated with outcome in different malignancies. The aim of the present study was to analyze the possible influence of the (-938C>A) SNP on survival of patients suffering from OSCC. One hundred and thirty-three patients with primary OSCC were retrospectively investigated. Bcl-2 expression of tumor cells was demonstrated by means of immunohistochemistry. Both the Bcl-2 expression and the (-938C>A) genotypes were correlated with the patients' survival. The (-938C>A) SNP was significantly related to Bcl-2 expression (P = 0.008). Kaplan-Meier curves revealed a significant association of the -938 SNP with relapse-free (P = 0.0283) and overall survival (P = 0.0247). Multiple Cox regression identified the BCL2 (-938CC) genotype as an independent prognostic factor for relapse [hazard ratio (HR) 1.898, P = 0.021] as well as for death in OSCC patients (HR 1.897, P = 0.013). The (-938C>A) SNP represents a potential novel prognostic marker in patients with OSCC that could help to identify a group of patients at high risk for relapse and death.

Pembrolizumab and Vorinostat in Treating Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma, Follicular Lymphoma, or Hodgkin Lymphoma

ClinicalTrials.gov

2018-04-23

Grade 3a Follicular Lymphoma; Grade 3b Follicular Lymphoma; Recurrent Classical Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Classical Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma

[Survival of patients with primary central nervous system diffuse large B-cell lymphoma: impact of gene aberrations and protein overexpression of bcl-2 and C-MYC, and selection of chemotherapy regimens].

PubMed

Yin, W J; Zhu, X; Yang, H Y; Sun, W Y; Wu, M J

2018-01-08

Objective: To investigate the impact of clinicopathological features, gene rearrangements and protein expression of bcl-6, bcl-2, C-MYC and chemotherapy regime on the prognosis of patients with primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL). Methods: Thirty-three cases of PCNS-DLBCL diagnosed from January 2006 to December 2016 at Zhejiang Cancer Hospital were collected. The expression of CD10, bcl-6, bcl-2, MUM1 and MYC were detected by immunohistochemical staining (IHC). The presence of EB virus was detected by in situ hybridization(EBER). Copy number variation (ICN) and translocation status of bcl-6, bcl-2 and C-MYC genes were detected by fluorescence in situ hybridization (FISH). The relationship between the above indexes and the prognosis was analyzed by univariate, bivariate survival analysis and multiple Cox hazard regression analysis. Results: The study included 33 patients of PCNS-DLBCL, without evidence of primary or secondary immunodeficient disease. Male to female ratio was 1.36∶1.00, and the average age was 56 years. Twenty cases had single lesion while 13 had multiple lesions. Deep brain involvement was seen in 12 cases. All patients underwent partial or total tumor resection. Five patients received whole brain post-surgery radiotherapy, nine patients received high-dose methotrexate (HD-MTX) based chemotherapy, and 12 patients received whole-brain radiotherapy combined with HD-MTX based chemotherapy. Severn patients received no further treatment and rituximab was used in 8 patients. According to the Hans model, 27 cases were classified as non-GCB subtypes (81.8%). Bcl-2 was positive in 25 cases (75.8%, 25/33) and highly expressed in 8 (24.2%). MYC was positive in 12 cases (36.4%) and double expression of bcl-2 and MYC was seen in 6 cases. EBER positive rate was 10.0%(3/30), all of which had multiple lesions. Two bcl-6 gene translocations and 3 amplifications were found in 28 patients. Two translocations, 3 ICN or with both

Genetics and Pathogenesis of Diffuse Large B-Cell Lymphoma.

PubMed

Schmitz, Roland; Wright, George W; Huang, Da Wei; Johnson, Calvin A; Phelan, James D; Wang, James Q; Roulland, Sandrine; Kasbekar, Monica; Young, Ryan M; Shaffer, Arthur L; Hodson, Daniel J; Xiao, Wenming; Yu, Xin; Yang, Yandan; Zhao, Hong; Xu, Weihong; Liu, Xuelu; Zhou, Bin; Du, Wei; Chan, Wing C; Jaffe, Elaine S; Gascoyne, Randy D; Connors, Joseph M; Campo, Elias; Lopez-Guillermo, Armando; Rosenwald, Andreas; Ott, German; Delabie, Jan; Rimsza, Lisa M; Tay Kuang Wei, Kevin; Zelenetz, Andrew D; Leonard, John P; Bartlett, Nancy L; Tran, Bao; Shetty, Jyoti; Zhao, Yongmei; Soppet, Dan R; Pittaluga, Stefania; Wilson, Wyndham H; Staudt, Louis M

2018-04-12

Diffuse large B-cell lymphomas (DLBCLs) are phenotypically and genetically heterogeneous. Gene-expression profiling has identified subgroups of DLBCL (activated B-cell-like [ABC], germinal-center B-cell-like [GCB], and unclassified) according to cell of origin that are associated with a differential response to chemotherapy and targeted agents. We sought to extend these findings by identifying genetic subtypes of DLBCL based on shared genomic abnormalities and to uncover therapeutic vulnerabilities based on tumor genetics. We studied 574 DLBCL biopsy samples using exome and transcriptome sequencing, array-based DNA copy-number analysis, and targeted amplicon resequencing of 372 genes to identify genes with recurrent aberrations. We developed and implemented an algorithm to discover genetic subtypes based on the co-occurrence of genetic alterations. We identified four prominent genetic subtypes in DLBCL, termed MCD (based on the co-occurrence of MYD88 L265P and CD79B mutations), BN2 (based on BCL6 fusions and NOTCH2 mutations), N1 (based on NOTCH1 mutations), and EZB (based on EZH2 mutations and BCL2 translocations). Genetic aberrations in multiple genes distinguished each genetic subtype from other DLBCLs. These subtypes differed phenotypically, as judged by differences in gene-expression signatures and responses to immunochemotherapy, with favorable survival in the BN2 and EZB subtypes and inferior outcomes in the MCD and N1 subtypes. Analysis of genetic pathways suggested that MCD and BN2 DLBCLs rely on "chronic active" B-cell receptor signaling that is amenable to therapeutic inhibition. We uncovered genetic subtypes of DLBCL with distinct genotypic, epigenetic, and clinical characteristics, providing a potential nosology for precision-medicine strategies in DLBCL. (Funded by the Intramural Research Program of the National Institutes of Health and others.).

MicroRNAs in B-cell lymphomas: how a complex biology gets more complex.

PubMed

Musilova, K; Mraz, M

2015-05-01

MicroRNAs (miRNAs) represent important regulators of gene expression besides transcriptional control. miRNA regulation can be involved in the cell developmental fate decisions, but can also have more subtle roles in buffering stochastic fluctuations in gene expression. They participate in pathways fundamental to B-cell development like B-cell receptor (BCR) signalling, B-cell migration/adhesion, cell-cell interactions in immune niches, and the production and class-switching of immunoglobulins. miRNAs influence B-cell maturation, generation of pre-, marginal zone, follicular, B1, plasma and memory B cells. In this review, we discuss miRNAs with essential functions in malignant B-cell development (such as miR-150, miR-155, miR-21, miR-34a, miR-17-92 and miR-15-16). We also put these miRNAs in the context of normal B-cell differentiation, as this is intimately connected to neoplastic B-cell development. We review miRNAs' role in the most common B-cell malignancies, including chronic lymphocytic leukaemia (CLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and mantle cell lymphoma (MCL). We focus on miR-contribution to the regulation of important signalling pathways (such as NF-κB, PI3K/AKT and TGF-β), BCR signalling and its modulators (such as PTEN, SHIP-1, ZAP-70, GAB1 and BTK), anti- and pro-apoptotic proteins (such as BCL2, MCL1, TCL1, BIM, p53 and SIRT1) and transcription factors (such as MYC, MYB, PU.1, FOXP1 and BCL6). We also discuss the association of miRNAs' expression levels with the patients' survival and response to therapy, summarizing their potential use as predictive and prognostic markers. Importantly, the targeting of miRNAs (like use of anti-miR-155 or miR-34a mimic) could provide a novel therapeutic approach as evidenced by tumour regression in xenograft mouse models and initial promising data from clinical trials.

The Bruton tyrosine kinase (BTK) inhibitor PCI-32765 synergistically increases proteasome inhibitor activity in diffuse large-B cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) cells sensitive or resistant to bortezomib.

PubMed

Dasmahapatra, Girija; Patel, Hiral; Dent, Paul; Fisher, Richard I; Friedberg, Jonathan; Grant, Steven

2013-04-01

Interactions between the Bruton tyrosine kinase (BTK) inhibitor PCI-32765 and the proteasome inhibitor (bortezomib) were examined in diffuse large-B cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) cells, including those highly resistant to bortezomib. Co-administration of PCI-32765/bortezomib synergistically increased mitochondrial injury and apoptosis in germinal centre- or activated B-cell-like-DLBCL cells and in MCL cells. These events were accompanied by marked AKT and nuclear factor (NF)-κB (NFKB1) inactivation, down-regulation of Mcl-1 (MCL1), Bcl-xL (BCL2L1), and XIAP, and enhanced DNA damage (e.g., γH2A.X formation) and endoplasmic reticulum (ER) stress. Similar interactions were observed in highly bortezomib-resistant DLBCL and MCL cells, and in primary DLBCL cells. In contrast, PCI-32765/bortezomib regimens displayed minimal toxicity toward normal CD34(+) bone marrow cells. Transfection of DLBCL cells with a constitutively active AKT construct attenuated AKT inactivation and significantly diminished cell death, whereas expression of an NF-κB "super-repressor" (IκBαser34/36 ) increased both PCI-32765 and bortezomib lethality. Moreover, cells in which the ER stress response was disabled by a dominant-negative eIF2α construct were resistant to this regimen. Finally, combined exposure to PCI-32765 and bortezomib resulted in more pronounced and sustained reactive oxygen species (ROS) generation, and ROS scavengers significantly diminished lethality. Given promising early clinical results for PCI-32765 in DLBCL and MCL, a strategy combining BTK/proteasome inhibitor warrants attention in these malignancies. © 2013 Blackwell Publishing Ltd.

How I treat double-hit lymphoma.

PubMed

Friedberg, Jonathan W

2017-08-03

The 2016 revision of the World Health Organization (WHO) classification for lymphoma has included a new category of lymphoma, separate from diffuse large B-cell lymphoma, termed high-grade B-cell lymphoma with translocations involving myc and bcl-2 or bcl-6 . These lymphomas, which occur in <10% of cases of diffuse large B-cell lymphoma, have been referred to as double-hit lymphomas (or triple-hit lymphomas if all 3 rearrangements are present). It is important to differentiate these lymphomas from the larger group of double-expressor lymphomas, which have increased expression of MYC and BCL-2 and/or BCL-6 by immunohistochemistry, by using variable cutoff percentages to define positivity. Patients with double-hit lymphomas have a poor prognosis when treated with standard chemoimmunotherapy and have increased risk of central nervous system involvement and progression. Double-hit lymphomas may arise as a consequence of the transformation of the underlying indolent lymphoma. There are no published prospective trials in double-hit lymphoma, however retrospective studies strongly suggest that aggressive induction regimens may confer a superior outcome. In this article, I review my approach to the evaluation and treatment of double-hit lymphoma, with an eye toward future clinical trials incorporating rational targeted agents into the therapeutic armamentarium. © 2017 by The American Society of Hematology.

Targeting Bcl-2 stability to sensitize cells harboring oncogenic ras.

PubMed

Peng, Bo; Ganapathy, Suthakar; Shen, Ling; Huang, Junchi; Yi, Bo; Zhou, Xiaodong; Dai, Wei; Chen, Changyan

2015-09-08

The pro-survival factor Bcl-2 and its family members are critical determinants of the threshold of the susceptibility of cells to apoptosis. Studies are shown that cells harboring an oncogenic ras were extremely sensitive to the inhibition of protein kinase C (PKC) and Bcl-2 could antagonize this apoptotic process. However, it remains unrevealed how Bcl-2 is being regulated in this apoptotic process. In this study, we investigate the role of Bcl-2 stability in sensitizing the cells harboring oncogenic K-ras to apoptosis triggered by PKC inhibitor GO6976. We demonstrated that Bcl-2 in Swiss3T3 cells ectopically expressing or murine lung cancer LKR cells harboring K-ras rapidly underwent ubiquitin-dependent proteasome pathway after the treatment of GO6976, accompanied with induction of apoptosis. In this process, Bcl-2 formed the complex with Keap-1 and Cul3. The mutation of serine-17 and deletion of BH-2 or 4 was required for Bcl-2 ubiquitination and degradation, which elevate the signal threshold for the induction of apoptosis in the cells following PKC inhibition. Thus, Bcl-2 appears an attractive target for the induction of apoptosis by PKC inhibition in cancer cells expressing oncogenic K-ras.

Inhibition of Oncogenic Transcription Factor REL by the Natural Product Derivative Calafianin Monomer 101 Induces Proliferation Arrest and Apoptosis in Human B-Lymphoma Cell Lines.

PubMed

Yeo, Alan T; Chennamadhavuni, Spandan; Whitty, Adrian; Porco, John A; Gilmore, Thomas D

2015-04-23

Increased activity of transcription factor NF-κB has been implicated in many B-cell lymphomas. We investigated effects of synthetic compound calafianin monomer (CM101) on biochemical and biological properties of NF-κB. In human 293 cells, CM101 selectively inhibited DNA binding by overexpressed NF-κB subunits REL (human c-Rel) and p65 as compared to NF-κB p50, and inhibition of REL and p65 DNA binding by CM101 required a conserved cysteine residue. CM101 also inhibited DNA binding by REL in human B-lymphoma cell lines, and the sensitivity of several B-lymphoma cell lines to CM101-induced proliferation arrest and apoptosis correlated with levels of cellular and nuclear REL. CM101 treatment induced both phosphorylation and decreased expression of anti-apoptotic protein Bcl-XL, a REL target gene product, in sensitive B-lymphoma cell lines. Ectopic expression of Bcl-XL protected SUDHL-2 B-lymphoma cells against CM101-induced apoptosis, and overexpression of a transforming mutant of REL decreased the sensitivity of BJAB B-lymphoma cells to CM101-induced apoptosis. Lipopolysaccharide-induced activation of NF-κB signaling upstream components occurred in RAW264.7 macrophages at CM101 concentrations that blocked NF-κB DNA binding. Direct inhibitors of REL may be useful for treating B-cell lymphomas in which REL is active, and may inhibit B-lymphoma cell growth at doses that do not affect some immune-related responses in normal cells.

Mangiferin inhibition of proliferation and induction of apoptosis in human prostate cancer cells is correlated with downregulation of B-cell lymphoma-2 and upregulation of microRNA-182.

PubMed

Li, Minglin; Ma, Huili; Yang, Lixin; Li, Peng

2016-01-01

Mangiferin, a flavonoid extracted from the mango tree, possesses anti-inflammatory, antibacterial, anti-herpes simplex and antitumor activity, and is able to affect immune function. The present study investigated the anticancer effects of mangiferin treatment on PC3 human prostate cancer cells, and the potential underlying mechanisms. In the present study, an MTT assay was used to analyze the proliferation of PC3 cells. Subsequently, flow cytometry and colorimetric assay kits were utilized to measure the PC3 cell apoptotic rate. The expression levels of B-cell lymphoma-2 (Bcl-2) and microRNA-182 (miR-182) were detected using western blot analysis and quantitative reverse transcription-polymerase chain reaction, respectively. Finally, miR-182 and anti-miR-182 were transfected into PC3 cells, which were used to investigate the effects of mangiferin. Mangiferin treatment reduced the proliferation of PC3 human prostate cancer cells in a concentration- and time-dependent manner. In addition, mangiferin was able to promote apoptosis and induce the caspase-3 activity of PC3 human prostate cancer cells. Mangiferin treatment was also able to significantly reduce Bcl-2 expression levels and enhance miR-182 expression in PC3 cells. Finally, it was observed that mangiferin inhibited proliferation and induced apoptosis in PC3 human prostate cancer cells, and this effect was correlated with downregulation of Bcl-2 and upregulation of miR-182.

Rituximab-induced inhibition of YY1 and Bcl-xL expression in Ramos non-Hodgkin's lymphoma cell line via inhibition of NF-kappa B activity: role of YY1 and Bcl-xL in Fas resistance and chemoresistance, respectively.

PubMed

Vega, Mario I; Jazirehi, Ali R; Huerta-Yepez, Sara; Bonavida, Benjamin

2005-08-15

Rituximab treatment of B non-Hodgkin's lymphoma (NHL) cell lines inhibits the constitutive NF-kappaB activity and results in the sensitization of tumor cells to both chemotherapy and Fas-induced apoptosis. Cells expressing dominant active IkappaB or treated with NF-kappaB-specific inhibitors were sensitive to both drugs and Fas agonist mAb (CH-11)-induced apoptosis. Down-regulation of Bcl-xL expression via inhibition of NF-kappaB activity correlated with chemosensitivity. The direct role of Bcl-xL in chemoresistance was demonstrated by the use of Bcl-xL-overexpressing Ramos cells, Ramos hemagglutinin (HA)-Bcl-x, which were not sensitized by rituximab to drug-induced apoptosis. However, inhibition of Bcl-xL in Ramos HA-Bcl-x resulted in sensitization to drug-induced apoptosis. The role of Bcl-xL expression in the regulation of Fas resistance was not apparent; Ramos HA-Bcl-x cells were as sensitive as the wild type to CH-11-induced apoptosis. Several lines of evidence support the direct role of the transcription repressor yin-yang 1 (YY1) in the regulation of resistance to CH-11-induced apoptosis. Inhibition of YY1 activity by either rituximab or the NO donor DETANONOate or after transfection with YY1 small interfering RNA resulted in up-regulation of Fas expression and sensitization to CH-11-induced apoptosis. These findings suggest two mechanisms underlying the chemosensitization and immunosensitization of B-NHL cells by rituximab via inhibition of NF-kappaB. The regulation of chemoresistance by NF-kappaB is mediated via Bcl-xL expression, whereas the regulation of Fas resistance by NF-kappaB is mediated via YY1 expression and activity. The potential clinical significance of these findings is discussed.

bcl-2 transgene inhibits T cell death and perturbs thymic self-censorship.

PubMed

Strasser, A; Harris, A W; Cory, S

1991-11-29

Early death is the fate of most developing T lymphocytes. Because bcl-2 can promote cell survival, we tested its impact in mice expressing an E mu-bcl-2 transgene within the T lymphoid compartment. The T cells showed remarkably sustained viability and some spontaneous differentiation in vitro. They also resisted killing by lymphotoxic agents. Although total T cell numbers and the rate of thymic involution were unaltered, the response to immunization was enhanced, consistent with reduced death of activated T cells. No T cells reactive with self-superantigens appeared in the lymph nodes, but an excess was found in the thymus. These observations, together with previous findings on B cells, suggest that modulated bcl-2 expression is a determinant of life and death in normal lymphocytes.

ABCG2 is a direct transcriptional target of hedgehog signaling and involved in stroma-induced drug tolerance in diffuse large B-cell lymphoma.

PubMed

Singh, R R; Kunkalla, K; Qu, C; Schlette, E; Neelapu, S S; Samaniego, F; Vega, F

2011-12-08

Successful treatment of diffuse large B-cell lymphoma (DLBCL) is frequently hindered by the development of resistance to conventional chemotherapy resulting in disease relapse and high mortality. High expression of antiapoptotic and/or drug transporter proteins induced by oncogenic signaling pathways has been implicated in the development of chemoresistance in cancer. Previously, our studies showed that high expression of adenosine triphosphate-binding cassette drug transporter ABCG2 in DLBCL correlated inversely with disease- and failure-free survival. In this study, we have implicated activated hedgehog (Hh) signaling pathway as a key factor behind high ABCG2 expression in DLBCL through direct upregulation of ABCG2 gene transcription. We have identified a single binding site for GLI transcription factors in the ABCG2 promoter and established its functionality using luciferase reporter, site-directed mutagenesis and chromatin-immunoprecipitation assays. Furthermore, in DLBCL tumor samples, significantly high ABCG2 and GLI1 levels were found in DLBCL tumors with lymph node involvement in comparison with DLBCL tumor cells collected from pleural and/or peritoneal effusions. This suggests a role for the stromal microenvironment in maintaining high levels of ABCG2 and GLI1. Accordingly, in vitro co-culture of DLBCL cells with HS-5 stromal cells increased ABCG2 mRNA and protein levels by paracrine activation of Hh signaling. In addition to ABCG2, co-culture of DLBCL cells with HS-5 cells also resulted in increase expression of the antiapoptotic proteins BCL2, BCL-xL and BCL2A1 and in induced chemotolerance to doxorubicin and methotrexate, drugs routinely used for the treatment of DLBCL. Similarly, activation of Hh signaling in DLBCL cell lines with recombinant Shh N-terminal peptide resulted in increased expression of BCL2 and ABCG2 associated with increased chemotolerance. Finally, functional inhibition of ABCG2 drug efflux activity with fumitremorgin C or inhibition

Immunoarchitectural patterns in nodal marginal zone B-cell lymphoma: a study of 51 cases.

PubMed

Salama, Mohamed E; Lossos, Izidore S; Warnke, Roger A; Natkunam, Yasodha

2009-07-01

Nodal marginal zone lymphoma (NMZL) represents a rare and heterogeneous group that lacks markers specific for the diagnosis. We evaluated morphologic and immunoarchitectural features of 51 NMZLs, and the following immunostains were performed: CD20, CD21, CD23, CD5, CD3, CD43, CD10, Ki-67, BCL1, BCL2, BCL6, HGAL, and LMO2. Four immunoarchitectural patterns were evident: diffuse (38 [75%]), well-formed nodular/follicular (5 [10%]), interfollicular (7 [14%]), and perifollicular (1 [2%]). Additional features included a monocytoid component (36 [71%]), admixed large cells (20 [39%]), plasma cells (24 [47%]), compartmentalizing stromal sclerosis (13 [25%]), and prominent blood vessel sclerosis (10 [20%]). CD21 highlighted disrupted follicular dendritic cell meshwork in 35 (71%) of 49 cases, and CD43 coexpression was present in 10 (24%) of 42 cases. A panel of germinal center-associated markers was helpful in eliminating cases of diffuse follicle center lymphoma. Our results highlight the histologic and immunoarchitectural spectrum of NMZL and the usefulness of immunohistochemical analysis for CD43, CD23, CD21, BCL6, HGAL, and LMO2 in the diagnosis of NMZL.

Epstein-Barr virus-positive diffuse large B-cell lymphoma in children: a disease reminiscent of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly.

PubMed

Uccini, Stefania; Al-Jadiry, Mazin F; Scarpino, Stefania; Ferraro, Daniela; Alsaadawi, Adel R; Al-Darraji, Amir F; Moleti, Maria Luisa; Testi, Anna Maria; Al-Hadad, Salma A; Ruco, Luigi

2015-05-01

Pediatric Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma (EBV+ DLBCL) is a rare disease in nonimmunocompromised hosts. In a review of 231 cases of malignant lymphoma (87 Hodgkin lymphoma and 144 non-Hodgkin lymphoma) occurring in Iraqi children, 7 cases (5% of NHLs) were classified as EBV+ DLBCL. Six children presented with nodal disease, and 1 presented with extranodal localization (bone). In all cases, the disease was at an advanced clinical stage (III/IV). Evidence of immunodeficiency (Evans syndrome and selective IgA deficiency) was observed in a single case. Two cases were "monomorphic" with immunoblastic histology, and 5 cases were "polymorphic" with histologic aspects reminiscent of nodular lymphocyte-predominant Hodgkin lymphoma (2 cases) and of CD30+ classical Hodgkin lymphoma (3 cases). In all cases, tumor cells were EBV infected (EBER+/LMP-1+), were medium-large B-cells (CD20+/CD79a+/PAX-5+/BOB-1+/OCT-2+) of non-germinal center (non-GC) origin (CD10-/MUM-1+), and had high proliferative activity (50%-70%). Chromosomal translocations involving BCL2, MYC, and IGH genes were not observed. IGH monoclonality could be demonstrated in 3 of 3 investigated cases. Six cases of EBV-negative DLBCL (4% of NHL) were present in the same series. All had monomorphic histology with centroblastic/immunoblastic morphology; 3 cases were of GC type and 3 of non-GC type. Our findings indicate that in Iraq, DLBCLs are 9% of NHLs. Moreover, 2 different types of the disease do exist; the EBV-positive cases, with strong histologic and immunohistochemical resemblance with EBV+ DLBCL of the elderly, and the EBV-negative cases, which are similar to the pediatric DLBCL usually observed in Western populations. Copyright © 2015 Elsevier Inc. All rights reserved.

The targeted inhibition of mitochondrial Hsp90 overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Chunlan; Department of Physiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058; Oh, Joon Seok

Previous studies have reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity, thus inducing the apoptotic pathway in the cells. Accordingly, G-TPP shows a potential as a promising drug for the treatment of cancer. A cell can die from different types of cell death such as apoptosis, necrosis, necroptosis, and autophagic cell death. In this study, we further investigated the mechanisms and modes of cell death in the G-TPP-treated Hep3B and U937 cell lines. We discovered that G-TPP kills the U937 cells through the apoptotic pathway and the overexpression of Bcl-2 significantlymore » inhibits U937 cell death to G-TPP. We further discovered that G-TPP kills the Hep3B cells by activating necroptosis in combination with the partial activation of caspase-dependent apoptosis. Importantly, G-TPP overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. We also observed that G-TPP induces compensatory autophagy in the Hep3B cell line. We further found that whereas there is a Bcl-2-Beclin 1 interaction in response to G-TPP, silencing the beclin 1 gene failed to block LC3-II accumulation in the Hep3B cells, indicating that G-TPP triggers Beclin 1-independent protective autophagy in Hep3B cells. Taken together, these data reveal that G-TPP induces cell death through a combination of death pathways, including necroptosis and apoptosis, and overcomes the apoptosis resistance conferred by Bcl-2 in Hep3B cells via necroptosis. These findings are important for the therapeutic exploitation of necroptosis as an alternative cell death program to bypass the resistance to apoptosis. Highlights: ► G-TPP binds to mitochondrial Hsp90. ► G-TPP induces apoptosis in U937 human leukemia cancer cells. ► G-TPP induces combination of death pathways in Hep3B cell. ► G-TPP overcomes the resistance conferred by Bcl-2 in Hep3B cells via necroptosis. ► G-TPP triggers Beclin 1

Inhibition of Bcl-2 potentiates AZD-2014-induced anti-head and neck squamous cell carcinoma cell activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yi; Cui, Jiang-Tao, E-mail: cuijingtaopaper@126.com

Mammalian target of rapamycin (mTOR) is a therapeutic target for head and neck squamous cell carcinoma (HNSCC). Here, we evaluated the activity of AZD-2014, a potent mTOR complex 1/2 (mTORC1/2) dual inhibitor, against HNSCC cells. We showed that AZD-2014 blocked mTORC1/2 activation in established and primary human HNSCC cells, where it was anti-proliferative and pro-apoptotic. Yet, AZD-2014 was non-cytotoxic to the human oral epithelial cells with low basal mTORC1/2 activation. In an effect to identify possible AZD-2014 resistance factors, we showed that the anti-apoptosis protein Bcl-2 was upregulated in AZD-2014-resistant SQ20B HNSCC cells. Inhibition of Bcl-2 by ABT-737 (a knownmore » Bcl-2 inhibitor) or Bcl-2 shRNA dramatically potentiated AZD-2014 lethality against HNSCC cells. On the other hand, exogenous overexpression of Bcl-2 largely attenuated AZD-2014’s activity against HNSCC cells. For the in vivo studies, we showed that oral gavage of AZD-2014 suppressed SQ20B xenograft growth in severe combined immunodeficient (SCID) mice. It also significantly improved mice survival. Importantly, AZD-2014’s anti-HNSCC activity in vivo was potentiated with co-administration of ABT-737. The preclinical results of this study suggest that AZD-2014 could be further tested as a valuable anti-HNSCC agent, either alone or in combination with Bcl-2 inhibitors. - Highlights: • AZD-2014 blocks mTORC1/2 activation in HNSCC cells. • AZD-2014 suppresses HNSCC cell proliferation. • AZD-2014 activates caspase-3 and apoptosis in HNSCC cells. • Bcl-2 is the key resistance factor of AZD-2014 in HNSCC cells. • ABT-737 sensitizes AZD-2014-induced anti-HNSCC activity in vivo.« less

Flow cytometric analysis of immunoglobulin heavy chain expression in B-cell lymphoma and reactive lymphoid hyperplasia

PubMed Central

Grier, David D; Al-Quran, Samer Z; Cardona, Diana M; Li, Ying; Braylan, Raul C

2012-01-01

The diagnosis of B-cell lymphoma (BCL) is often dependent on the detection of clonal immunoglobulin (Ig) light chain expression. In some BCLs, the determination of clonality based on Ig light chain restriction may be difficult. The aim of our study was to assess the utility of flow cytometric analysis of surface Ig heavy chain (HC) expression in lymphoid tissues in distinguishing lymphoid hyperplasias from BCLs, and also differentiating various BCL subtypes. HC expression on B-cells varied among different types of hyperplasias. In follicular hyperplasia, IgM and IgD expression was high in mantle cells while germinal center cells showed poor HC expression. In other hyperplasias, B cell compartments were blurred but generally showed high IgD and IgM expression. Compared to hyperplasias, BCLs varied in IgM expression. Small lymphocytic lymphomas had lower IgM expression than mantle cell lymphomas. Of importance, IgD expression was significantly lower in BCLs than in hyperplasias, a finding that can be useful in differentiating lymphoma from reactive processes. PMID:22400070

Effects of apigenin on the expression levels of B-cell lymphoma-2, Fas and Fas ligand in renal ischemia-reperfusion injury in rats.

PubMed

Liu, Yang; Liu, Xiuheng; Wang, Lei; Du, Yang; Chen, Zhiyuan; Chen, Hui; Guo, Jia; Weng, Xiaodong; Wang, Xiao; Wang, Ming; Wang, Zhishun

2017-12-01

The aim of the present study was to investigate the effect and possible mechanism of apigenin on renal ischemia-reperfusion (I/R) injury in rats, as well as in in vitro experiments. In total, 36 rats were subjected to 45 min of renal ischemia, with or without treatment prior to ischemia with different concentrations of apigenin (2, 10 and 50 mg/kg) administered intravenously. All rats were sacrificed at 24 h after I/R injury. The serum creatinine (Cr) and blood urea nitrogen (BUN) levels were analyzed, and histological examination was conducted. In addition, the expression levels of B-cell lymphoma 2 (Bcl-2) and Fas/Fas ligand (FasL) were detected by immunohistochemistry, reverse transcription-quantitative polymerase chain reaction and western blot analysis. For in vitro experiments, the NRK-52E cell line was employed. The viability, apoptosis and expression levels of Fas, FasL and Bcl-2 were examined in the culture of NRK-52E cells following the I/R. The results indicated that apigenin significantly decreased the levels of serum Cr and BUN induced by renal I/R, demonstrating an improvement in renal function. The histological evidence of renal damage associated with I/R was also mitigated by apigenin in vivo . Furthermore, apigenin increased the cell viability and decreased cell apoptosis in the culture of NRK52E after I/R in vitro . Compared with the I/R group, the expression of Bcl-2 was upregulated and the expression levels of Fas and FasL were downregulated by apigenin at the mRNA and protein levels in vivo and in vitro . In conclusion, apigenin appeared to increase the expression of Bcl-2 and reduce Fas/FasL expression in renal I/R injury, providing evident protection against renal I/R injury in rats.

Effects of apigenin on the expression levels of B-cell lymphoma-2, Fas and Fas ligand in renal ischemia-reperfusion injury in rats

PubMed Central

Liu, Yang; Liu, Xiuheng; Wang, Lei; Du, Yang; Chen, Zhiyuan; Chen, Hui; Guo, Jia; Weng, Xiaodong; Wang, Xiao; Wang, Ming; Wang, Zhishun

2017-01-01

The aim of the present study was to investigate the effect and possible mechanism of apigenin on renal ischemia-reperfusion (I/R) injury in rats, as well as in in vitro experiments. In total, 36 rats were subjected to 45 min of renal ischemia, with or without treatment prior to ischemia with different concentrations of apigenin (2, 10 and 50 mg/kg) administered intravenously. All rats were sacrificed at 24 h after I/R injury. The serum creatinine (Cr) and blood urea nitrogen (BUN) levels were analyzed, and histological examination was conducted. In addition, the expression levels of B-cell lymphoma 2 (Bcl-2) and Fas/Fas ligand (FasL) were detected by immunohistochemistry, reverse transcription-quantitative polymerase chain reaction and western blot analysis. For in vitro experiments, the NRK-52E cell line was employed. The viability, apoptosis and expression levels of Fas, FasL and Bcl-2 were examined in the culture of NRK-52E cells following the I/R. The results indicated that apigenin significantly decreased the levels of serum Cr and BUN induced by renal I/R, demonstrating an improvement in renal function. The histological evidence of renal damage associated with I/R was also mitigated by apigenin in vivo. Furthermore, apigenin increased the cell viability and decreased cell apoptosis in the culture of NRK52E after I/R in vitro. Compared with the I/R group, the expression of Bcl-2 was upregulated and the expression levels of Fas and FasL were downregulated by apigenin at the mRNA and protein levels in vivo and in vitro. In conclusion, apigenin appeared to increase the expression of Bcl-2 and reduce Fas/FasL expression in renal I/R injury, providing evident protection against renal I/R injury in rats. PMID:29285062

PD1 and PDL1 expression in primary central nervous system diffuse large B-cell lymphoma are frequent and expression of PD1 predicts poor survival.

PubMed

Four, Marion; Cacheux, Valère; Tempier, Ariane; Platero, Dolorès; Fabbro, Michel; Marin, Grégory; Leventoux, Nicolas; Rigau, Valérie; Costes-Martineau, Valérie; Szablewski, Vanessa

2017-12-01

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a rare and aggressive type of diffuse large B-cell lymphoma (DLBCL) whit poorly understood pathogenesis. Finding biomarkers associated with patient survival may be important for understanding its physiopathology and to develop new therapeutic approaches. We investigated 32 PCNS-DLBCL from immunocompetent patients for BCL2, CMYC, LMO2, and P53 expression and for cytogenetic aberrations of BCL2, BCL6, and MYC genes, all known for their prognostic value in systemic DLBCL (s-DLBCL). We analyzed PD1 and PDL1 protein expression in both tumor infiltrating lymphocytes (TILs) and tumor cells. Finally, we searched for correlation between biological data and clinical course. The PCNS-DLBCL expressed BCL2, CMYC, LMO2, and P53 at similar frequency than s-DLBCL but without significant prognostic on survival. None cases harbored aberrations involving BCL2 and MYC gene whereas BCL6 abnormalities were present in 20.7% of cases but without value on survival. Expression of PD1 in TILs and PDL1 in tumor cells was observed at higher rates than in s-DLBCL (58% and 37%, respectively). The PD1 expression in TILs correlated with PDL1 expression in tumor cells (P = .001). Presence of PD1 positive TILs was associated with poorer overall survival (P = .011). Patients with PDL1 overexpression tended to better response to chemotherapy (P = .23). In conclusion PCNS-DLBCL pathogenesis differs from s-DLBCL without prognostic value of the phenotypic and cytogenetic parameters known for their pejorative impact in the latter. The PD1/PDL1 pathway plays a strong role in PCNS-DLBCL and represents an attractive target for this aggressive lymphoma. Copyright © 2016 John Wiley & Sons, Ltd.

An antiapoptotic Bcl-2 family protein index predicts the response of leukaemic cells to the pan-Bcl-2 inhibitor S1

PubMed Central

Zhang, Z; Liu, Y; Song, T; Xue, Z; Shen, X; Liang, F; Zhao, Y; Li, Z; Sheng, H

2013-01-01

Background: Bcl-2-like members have been found to be inherently overexpressed in many types of haematologic malignancies. The small-molecule S1 is a BH3 mimetic and a triple inhibitor of Bcl-2, Mcl-1 and Bcl-XL. Methods: The lethal dose 50 (LD50) values of S1 in five leukaemic cell lines and 41 newly diagnosed leukaemia samples were tested. The levels of Bcl-2 family members and phosphorylated Bcl-2 were semiquantitatively measured by western blotting. The interactions between Bcl-2 family members were tested by co-immunoprecipitation. The correlation between the LD50 and expression levels of Bcl-2 family members, alone or in combination, was analysed. Results: S1 exhibited variable sensitivity with LD50 values ranging >2 logs in both established and primary leukaemic cells. The ratio of pBcl-2/(Bcl-2+Mcl-1) could predict the S1 response. Furthermore, we demonstrated that pBcl-2 antagonised S1 by sequestering the Bak and Bim proteins that were released from Mcl-1, andpBcl-2/Bak, pBcl-2/Bax and pBcl-2/Bim complexes cannot be disrupted by S1. Conclusion: A predictive index was obtained for the novel BH3 mimetic S1. The shift of proapoptotic proteins from being complexed with Mcl-1 to being complexed with pBcl-2 was revealed for the first time, which is the mechanism underlying the index value described herein. PMID:23558901

Aggressive B-cell lymphomas in the update of the 4th edition of the World Health Organization classification of haematopoietic and lymphatic tissues: refinements of the classification, new entities and genetic findings.

PubMed

Ott, German

2017-09-01

The update of the 4th edition of the World Health Organization Classification of Haematopoietic and Lymphatic Tissues portends important new findings and concepts in the diagnosis, classification and biology of lymphomas. This review summarizes the basic concepts and cornerstones of the classification of aggressive B-cell lymphomas and details the major changes. Of importance, there is a new concept of High-grade B-cell lymphomas (HGBL), partly replacing the provisional entity of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma, the so-called grey zone lymphomas. They either harbour MYC translocations together with a BCL2 and/or a BCL6 rearrangement (HGBL-Double Hit) or HGBL, not otherwise specified (NOS), lacking a double or triple hit constellation. In addition, the requirement for providing the cell-of-origin classification in the diagnostic work-up of DLBCLs, the role of MYC alterations in DLBCL subtypes, and newer findings in the specific variants/subtypes are highlighted. © 2017 John Wiley & Sons Ltd.

Impaired removal of Vβ8(+) lymphocytes aggravates colitis in mice deficient for B cell lymphoma-2-interacting mediator of cell death (Bim).

PubMed

Leucht, K; Caj, M; Fried, M; Rogler, G; Hausmann, M

2013-09-01

We investigated the role of B cell lymphoma (BCL)-2-interacting mediator of cell death (Bim) for lymphocyte homeostasis in intestinal mucosa. Lymphocytes lacking Bim are refractory to apoptosis. Chronic colitis was induced in Bim-deficient mice (Bim(-/-) ) with dextran sulphate sodium (DSS). Weight loss and colonoscopic score were increased significantly in Bim(-/-) mice compared to wild-type mice. As Bim is induced for the killing of autoreactive cells we determined the role of Bim in the regulation of lymphocyte survival at mucosal sites. Upon chronic dextran sulphate sodium (DSS)-induced colitis, Bim(-/-) animals exhibited an increased infiltrate of lymphocytes into the mucosa compared to wild-type mice. The number of autoreactive T cell receptor (TCR) Vβ8(+) lymphocytes was significantly higher in Bim(-/-) mice compared to wild-type controls. Impaired removal of autoreactive lymphocytes in Bim(-/-) mice upon chronic DSS-induced colitis may therefore contribute to aggravated mucosal inflammation. © 2013 British Society for Immunology.

Post-Transcriptional Regulation of BCL2 mRNA by the RNA-Binding Protein ZFP36L1 in Malignant B Cells

PubMed Central

Zekavati, Anna; Nasir, Asghar; Alcaraz, Amor; Aldrovandi, Maceler; Marsh, Phil; Norton, John D.; Murphy, John J.

2014-01-01

The human ZFP36 zinc finger protein family consists of ZFP36, ZFP36L1, and ZFP36L2. These proteins regulate various cellular processes, including cell apoptosis, by binding to adenine uridine rich elements in the 3′ untranslated regions of sets of target mRNAs to promote their degradation. The pro-apoptotic and other functions of ZFP36 family members have been implicated in the pathogenesis of lymphoid malignancies. To identify candidate mRNAs that are targeted in the pro-apoptotic response by ZFP36L1, we reverse-engineered a gene regulatory network for all three ZFP36 family members using the ‘maximum information coefficient’ (MIC) for target gene inference on a large microarray gene expression dataset representing cells of diverse histological origin. Of the three inferred ZFP36L1 mRNA targets that were identified, we focussed on experimental validation of mRNA for the pro-survival protein, BCL2, as a target for ZFP36L1. RNA electrophoretic mobility shift assay experiments revealed that ZFP36L1 interacted with the BCL2 adenine uridine rich element. In murine BCL1 leukemia cells stably transduced with a ZFP36L1 ShRNA lentiviral construct, BCL2 mRNA degradation was significantly delayed compared to control lentiviral expressing cells and ZFP36L1 knockdown in different cell types (BCL1, ACHN, Ramos), resulted in increased levels of BCL2 mRNA levels compared to control cells. 3′ untranslated region luciferase reporter assays in HEK293T cells showed that wild type but not zinc finger mutant ZFP36L1 protein was able to downregulate a BCL2 construct containing the BCL2 adenine uridine rich element and removal of the adenine uridine rich core from the BCL2 3′ untranslated region in the reporter construct significantly reduced the ability of ZFP36L1 to mediate this effect. Taken together, our data are consistent with ZFP36L1 interacting with and mediating degradation of BCL2 mRNA as an important target through which ZFP36L1 mediates its pro-apoptotic effects in

The survival decrease in gastric cancer is associated with the methylation of B-cell CLL/lymphoma 6 member B promoter.

PubMed

Deng, Jingyu; Liang, Han; Dong, Qiuping; Hou, Yachao; Xie, Xingming; Yu, Jun; Fan, Daiming; Hao, Xishan

2014-07-01

The methylation of B-cell CLL/lymphoma 6 member B (BCL6B) DNA promoter was detected in several malignancies. Here, we quantitatively detect the methylated status of CpG sites of BCL6B DNA promoter of 459 patients with gastric cancer (GC) by using bisulfite gene sequencing. We show that patients with three or more methylated CpG sites in the BCL6B promoter were significantly associated with poor survival. Furthermore, by using the Akaike information criterion value calculation, we show that the methylated count of BCL6B promoter was identified to be the optimal prognostic predictor of GC patients.

Enhancing the anti-lymphoma potential of 3,4-methylenedioxymethamphetamine ('ecstasy') through iterative chemical redesign: mechanisms and pathways to cell death.

PubMed

Wasik, Agata M; Gandy, Michael N; McIldowie, Matthew; Holder, Michelle J; Chamba, Anita; Challa, Anita; Lewis, Katie D; Young, Stephen P; Scheel-Toellner, Dagmar; Dyer, Martin J; Barnes, Nicholas M; Piggott, Matthew J; Gordon, John

2012-08-01

While 3,4-methylenedioxymethamphetamine (MDMA/'ecstasy') is cytostatic towards lymphoma cells in vitro, the concentrations required militate against its translation directly to a therapeutic in vivo. The possibility of 'redesigning the designer drug', separating desired anti-lymphoma activity from unwanted psychoactivity and neurotoxicity, was therefore mooted. From an initial analysis of MDMA analogues synthesized with a modified α-substituent, it was found that incorporating a phenyl group increased potency against sensitive, Bcl-2-deplete, Burkitt's lymphoma (BL) cells 10-fold relative to MDMA. From this lead, related analogs were synthesized with the 'best' compounds (containing 1- and 2-naphthyl and para-biphenyl substituents) some 100-fold more potent than MDMA versus the BL target. When assessed against derived lines from a diversity of B-cell tumors MDMA analogues were seen to impact the broad spectrum of malignancy. Expressing a BCL2 transgene in BL cells afforded only scant protection against the analogues and across the malignancies no significant correlation between constitutive Bcl-2 levels and sensitivity to compounds was observed. Bcl-2-deplete cells displayed hallmarks of apoptotic death in response to the analogues while BCL2 overexpressing equivalents died in a caspase-3-independent manner. Despite lymphoma cells expressing monoamine transporters, their pharmacological blockade failed to reverse the anti-lymphoma actions of the analogues studied. Neither did reactive oxygen species account for ensuing cell death. Enhanced cytotoxic performance did however track with predicted lipophilicity amongst the designed compounds. In conclusion, MDMA analogues have been discovered with enhanced cytotoxic efficacy against lymphoma subtypes amongst which high-level Bcl-2--often a barrier to drug performance for this indication--fails to protect.

Apoptosis in differentiating C2C12 muscle cells selectively targets Bcl-2-deficient myotubes

PubMed Central

Schoneich, Christian; Dremina, Elena; Galeva, Nadezhda; Sharov, Victor

2014-01-01

Muscle cell apoptosis accompanies normal muscle development and regeneration, as well as degenerative diseases and aging. C2C12 murine myoblast cells represent a common model to study muscle differentiation. Though it was already shown that myogenic differentiation of C2C12 cells is accompanied by enhanced apoptosis in a fraction of cells, either the cell population sensitive to apoptosis or regulatory mechanisms for the apoptotic response are unclear so far. In the current study we characterize apoptotic phenotypes of different types of C2C12 cells at all stages of differentiation, and report here that myotubes of differentiated C2C12 cells with low levels of anti-apoptotic Bcl-2 expression are particularly vulnerable to apoptosis even though they are displaying low levels of pro-apoptotic proteins Bax, Bak and Bad. In contrast, reserve cells exhibit higher levels of Bcl-2 and high resistance to apoptosis. The transfection of proliferating myoblasts with Bcl-2 prior to differentiation did not protect against spontaneous apoptosis accompanying differentiation of C2C12 cell but led to Bcl-2 overexpression in myotubes and to significant protection from apoptotic cell loss caused by exposure to hydrogen peroxide. Overall, our data advocate for a Bcl-2-dependent mechanism of apoptosis in differentiated muscle cells. However, downstream processes for spontaneous and hydrogen peroxide induced apoptosis are not completely similar. Apoptosis in differentiating myoblasts and myotubes is regulated not through interaction of Bcl-2 with pro-apoptotic Bcl-2 family proteins such as Bax, Bak, and Bad. PMID:24129924

Quercetin inhibits the invasion and mobility of murine melanoma B16-BL6 cells through inducing apoptosis via decreasing Bcl-2 expression.

PubMed

Zhang, X; Xu, Q; Saiki, I

2000-01-01

Quercetin has been known to have anti-tumor and anti-oxidation activities. In the present study, we have investigated its in vitro anti-metastatic activity. Quercetin inhibited the invasion and mobility of murine melanoma B16-BL6 cells in a dose-dependent manner but did not affect their adhesion to either laminin, fibronectin, or type VI collagen. Moreover, quercetin significantly inhibited the proliferation of B16-BL6 cells only in the case of time incubation longer than 48 h. Quercetin dose-dependently decreased the cell rates in S and G2-M phases of cell cycle. The effect of quercetin to cause a remarkable apoptosis of B16-BL6 cells was also demonstrated by flow cytometric assay as well as DNA fragmentation with a typical 180-bp ladder band in agarose electrophoresis and a quantitative analysis. Furthermore, quercetin markedly inhibited the expression of anti-apoptotic protein Bcl-2 but hardly influenced Bcl-XL. These results suggest that the inhibition of quercetin on invasiveness and migration of B16-BL6 cells are closely associated with the arrest of cell cycle as well as the induction of apoptosis by decreasing the Bcl-2 expression.

In non-transformed cells Bak activates upon loss of anti-apoptotic Bcl-XL and Mcl-1 but in the absence of active BH3-only proteins.

PubMed

Senft, D; Weber, A; Saathoff, F; Berking, C; Heppt, M V; Kammerbauer, C; Rothenfusser, S; Kellner, S; Kurgyis, Z; Besch, R; Häcker, G

2015-11-26

Mitochondrial apoptosis is controlled by proteins of the B-cell lymphoma 2 (Bcl-2) family. Pro-apoptotic members of this family, known as BH3-only proteins, initiate activation of the effectors Bcl-2-associated X protein (Bax) and Bcl-2 homologous antagonist/killer (Bak), which is counteracted by anti-apoptotic family members. How the interactions of Bcl-2 proteins regulate cell death is still not entirely clear. Here, we show that in the absence of extrinsic apoptotic stimuli Bak activates without detectable contribution from BH3-only proteins, and cell survival depends on anti-apoptotic Bcl-2 molecules. All anti-apoptotic Bcl-2 proteins were targeted via RNA interference alone or in combinations of two in primary human fibroblasts. Simultaneous targeting of B-cell lymphoma-extra large and myeloid cell leukemia sequence 1 led to apoptosis in several cell types. Apoptosis depended on Bak whereas Bax was dispensable. Activator BH3-only proteins were not required for apoptosis induction as apoptosis was unaltered in the absence of all BH3-only proteins known to activate Bax or Bak directly, Bcl-2-interacting mediator of cell death, BH3-interacting domain death agonist and p53-upregulated modulator of apoptosis. These findings argue for auto-activation of Bak in the absence of anti-apoptotic Bcl-2 proteins and provide evidence of profound differences in the activation of Bax and Bak.

Selective targeting of JAK/STAT signaling is potentiated by Bcl-xL blockade in IL-2–dependent adult T-cell leukemia

PubMed Central

Zhang, Meili; Mathews Griner, Lesley A.; Ju, Wei; Duveau, Damien Y.; Guha, Rajarshi; Petrus, Michael N.; Wen, Bernard; Maeda, Michiyuki; Shinn, Paul; Ferrer, Marc; Conlon, Kevin D.; Bamford, Richard N.; O’Shea, John J.; Thomas, Craig J.; Waldmann, Thomas A.

2015-01-01

Adult T-cell leukemia (ATL) develops in individuals infected with human T-cell lymphotropic virus-1 (HTLV-1). Presently there is no curative therapy for ATL. HTLV-1–encoded protein Tax (transactivator from the X-gene region) up-regulates Bcl-xL (B-cell lymphoma-extra large) expression and activates interleukin-2 (IL-2), IL-9, and IL-15 autocrine/paracrine systems, resulting in amplified JAK/STAT signaling. Inhibition of JAK signaling reduces cytokine-dependent ex vivo proliferation of peripheral blood mononuclear cells (PBMCs) from ATL patients in smoldering/chronic stages. Currently, two JAK inhibitors are approved for human use. In this study, we examined activity of multiple JAK inhibitors in ATL cell lines. The selective JAK inhibitor ruxolitinib was examined in a high-throughput matrix screen combined with >450 potential therapeutic agents, and Bcl-2/Bcl-xL inhibitor navitoclax was identified as a strong candidate for multicomponent therapy. The combination was noted to strongly activate BAX (Bcl-2-associated X protein), effect mitochondrial depolarization, and increase caspase 3/7 activities that lead to cleavage of PARP (poly ADP ribose polymerase) and Mcl-1 (myeloid cell leukemia 1). Ruxolitinib and navitoclax independently demonstrated modest antitumor efficacy, whereas the combination dramatically lowered tumor burden and prolonged survival in an ATL murine model. This combination strongly blocked ex vivo proliferation of five ATL patients’ PBMCs. These studies provide support for a therapeutic trial in patients with smoldering/chronic ATL using a drug combination that inhibits JAK signaling and antiapoptotic protein Bcl-xL. PMID:26396258

Cell of origin of transformed follicular lymphoma

PubMed Central

Kridel, Robert; Mottok, Anja; Farinha, Pedro; Ben-Neriah, Susana; Ennishi, Daisuke; Zheng, Yvonne; Chavez, Elizabeth A.; Shulha, Hennady P.; Tan, King; Chan, Fong Chun; Boyle, Merrill; Meissner, Barbara; Telenius, Adele; Sehn, Laurie H.; Marra, Marco A.; Shah, Sohrab P.; Steidl, Christian; Connors, Joseph M.; Scott, David W.

2015-01-01

Follicular lymphoma (FL) is an indolent disease but transforms in 2% to 3% of patients per year into aggressive, large cell lymphoma, a critical event in the course of the disease associated with increased lymphoma-related mortality. Early transformation cannot be accurately predicted at the time of FL diagnosis and the biology of transformed FL (TFL) is poorly understood. Here, we assembled a cohort of 126 diagnostic FL specimens including 40 patients experiencing transformation (<5 years) and 86 patients not experiencing transformation for at least 5 years. In addition, we assembled an overlapping cohort of 155 TFL patients, including 114 cases for which paired samples were available, and assessed temporal changes of routinely available biomarkers, outcome after transformation, as well as molecular subtypes of TFL. We report that the expression of IRF4 is an independent predictor of early transformation (Hazard ratio, 13.3; P < .001). We also show that composite histology at the time of transformation predicts favorable prognosis. Moreover, applying the Lymph2Cx digital gene expression assay for diffuse large B-cell lymphoma (DLBCL) cell-of-origin determination to 110 patients with DLBCL-like TFL, we demonstrate that TFL is of the germinal-center B-cell–like subtype in the majority of cases (80%) but that a significant proportion of cases is of the activated B-cell–like (ABC) subtype (16%). These latter cases are commonly negative for BCL2 translocation and arise preferentially from BCL2 translocation-negative and/or IRF4-expressing FLs. Our study demonstrates the existence of molecular heterogeneity in TFL as well as its relationship to the antecedent FL. PMID:26307535

HIF-1α activates hypoxia-induced BCL-9 expression in human colorectal cancer cells

PubMed Central

Chen, Tian-Rui; Wei, Hai-feng; Song, Dian-Wen; Liu, Tie-Long; Yang, Xing-Hai; Fu, Chuan-Gang; Hu, Zhi-qian; Zhou, Wang; Yan, Wang-Jun; Xiao, Jian-Ru

2017-01-01

B-cell CLL/lymphoma 9 protein (BCL-9), a multi-functional co-factor in Wnt signaling, induced carcinogenesis as well as promoting tumor progression, metastasis and chemo-resistance in colorectal cancer (CRC). However, the mechanisms for increased BCL-9 expression in CRC were not well understood. Here, we report that hypoxia, a hallmark of solid tumors, induced BCL-9 mRNA expression in human CRC cells. Analysis of BCL-9 promoter revealed two functional hypoxia-responsive elements (HRE-B and HRE-C) that can be specifically bound with and be transactivated by hypoxia inducible factors (HIF) -1α but not HIF-2α. Consistently, ectopic expression of HIF-1α but not HIF-2α transcriptionally induced BCL-9 expression levels in cells. Knockdown of endogenous HIF-1α but not HIF-2α by siRNA largely abolished the induction of HIF by hypoxia. Furthermore, there was a strong association of HIF-1α expression with BCL-9 expression in human CRC specimens. In summary, results from this study demonstrated that hypoxia induced BCL-9 expression in human CRC cells mainly through HIF-1α, which could be an important underlying mechanism for increased BCL-9 expression in CRC. PMID:27121066

Effect of citral on the cytotoxicity of doxorubicin in human B-lymphoma cells.

PubMed

Dangkong, Darinee; Limpanasithikul, Wacharee

2015-02-01

Doxorubicin is a chemotherapy agent used in non-Hodgkin's lymphoma but side effects limit its use. Citral is a mixture of neral and geranial found in essential oils of lemon grass. We evaluated the activity of citral, doxorubicin, and combination on cytotoxicity, apoptosis, and anti-proliferative effects using human lymphoma Ramos cells. Cells were treated with doxorubicin alone or in combination with citral (10, 20, and 40 μM). Cytotoxic and apoptosis studies were done after 24 and 18 h incubations, respectively. Cytotoxic effects of citral on normal human peripheral blood mononuclear cells (PBMCs) were also investigated for its safety. Changes in the expression of BCL-2 family genes were analyzed by quantitative RT-PCR. Citral had cytotoxicity on cells with an IC50 value of 77.19 ± 4.95 µM. Citral at concentrations of 10, 20, and 40 µM additively increased the cytotoxic and apoptotic effects of doxorubicin, leading to decreased IC50 (µM) of the drug from 2.50 ± 0.01 to 2.16 ± 0.03, 1.90 ± 0.04, and 1.23 ± 0.04, respectively. Enhanced cytotoxicity was not observed in normal human PBMCs. Citral (40 µM) in combination with doxorubicin (1.5 µM) increased the expression of pro-apoptotic protein BAK but significantly decreased the expression of anti-apoptotic protein BCL-XL to 5.26-fold compared with doxorubicin-treated cells. It did not change the anti-proliferative activity of drug. Citral potentiated cytotoxicity of doxorubicin by increasing apoptotic effects. We conclude that citral may have beneficial effects in patients with B cell lymphoma treated with chemotherapy.

Aggressive B cell Lymphoma: Optimal Therapy for MYC-positive, Double-Hit, and Triple-Hit DLBCL.

PubMed

Dunleavy, Kieron

2015-12-01

Approximately 10% of cases of diffuse large B cell lymphoma (DLBCL) harbor a MYC rearrangement and this has been associated with an inferior outcome following standard therapy across many different studies. Double-hit and triple-hit lymphomas harbor concurrent rearrangements of MYC and BCL2 and/or BCL6 and are also associated with a very aggressive course and poor clinical outcome. It is unclear and there is lack of consensus on how these diseases should be approached therapeutically. They are characterized typically by high tumor proliferation and likely require Burkitt lymphoma-type strategies and several retrospective studies suggest that more intensive approaches than rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) may be beneficial. One challenge in this respect is that most patients with these diseases are older than 60 years and generally have poor tolerability of regimens typically used in Burkitt lymphoma. Dose-adjusted EPOCH-R is an alternative effective immunochemotherapy platform for DLBCL and is effective in Burkitt lymphoma, and retrospective studies suggest that it is effective and feasible in patients with DLBCL that harbors a MYC rearrangement with or without a BCL-2 translocation (double-hit). A multicenter study of this approach in MYC-rearranged DLBCL is ongoing and preliminary results are very encouraging. There is a lack of consensus on the role of consolidation stem cell transplantation in patients who achieve a good response to initial therapy but at this point in time, no (retrospective) studies have demonstrated any benefit. These diseases are also associated with a high rate of CNS involvement and progression and checking for cerebrospinal fluid by cytology and flow cytometry at initial diagnosis should be considered. In summary, based on retrospective data and preliminary prospective data (as more mature data is awaited), while Burkitt-type regimens may be feasible in young patients, DA-EPOCH-R is a

Overexpression of B-cell lymphoma 6 alters gene expression profile in a myeloma cell line and is associated with decreased DNA damage response.

PubMed

Tahara, Kenichi; Takizawa, Makiko; Yamane, Arito; Osaki, Yohei; Ishizaki, Takuma; Mitsui, Takeki; Yokohama, Akihiko; Saitoh, Takayuki; Tsukamoto, Norifumi; Matsumoto, Morio; Murakami, Hirokazu; Nojima, Yoshihisa; Handa, Hiroshi

2017-08-01

B-cell lymphoma 6 (BCL6) attenuates DNA damage response (DDR) through gene repression and facilitates tolerance to genomic instability during immunoglobulin affinity maturation in germinal center (GC) B cells. Although BCL6 expression is repressed through normal differentiation of GC B cells into plasma cells, a recent study showed the ectopic expression of BCL6 in primary multiple myeloma (MM) cells. However, the functional roles of BCL6 in MM cells are largely unknown. Here, we report that overexpression of BCL6 in a MM cell line, KMS12PE, induced transcriptional repression of ataxia telangiectasia mutated (ATM), a DDR signaling kinase, which was associated with a reduction in γH2AX formation after DNA damage. In contrast, transcription of known targets of BCL6 in GC B cells was not affected, suggesting a cell type-specific function of BCL6. To further investigate the effects of BCL6 overexpression on the MM cell line, we undertook mRNA sequence analysis and found an upregulation in the genomic mutator activation-induced cytidine deaminase (AID) with alteration in the gene expression profile, which is suggestive of de-differentiation from plasma cells. Moreover, interleukin-6 exposure to KMS12PE led to upregulation of BCL6 and AID, downregulation of ATM, and attenuation of DDR, which were consistent with the effects of BCL6 overexpression in this MM cell line. Taken together, these results indicated that overexpression of BCL6 alters gene expression profile and confers decreased DDR in MM cells. This phenotypic change could be reproduced by interleukin-6 stimulation, suggesting an important role of external stimuli in inducing genomic instability, which is a hallmark of MM cells. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Safflor yellow B suppresses angiotensin II-mediated human umbilical vein cell injury via regulation of Bcl-2/p22{sup phox} expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chaoyun; He, Yanhao; Department of Pharmacology, Xi'an Jiaotong University School of Medicine, Key Laboratory of Environment and Genes Related to Disease, Ministry of Education, Xi'an, Shaanxi 710061

Intracellular reactive oxygen species (ROS) are derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Angiotensin II (Ang II) can cause endothelial dysfunction by promoting intracellular ROS generation. Safflor yellow B (SYB) effectively inhibits ROS generation by upregulating Bcl-2 expression. In this study, we examined the effects of SYB on Ang II-induced injury to human umbilical vein endothelial cells (HUVECs), and elucidated the roles of NADPH oxidase and Bcl-2. We treated cultured HUVECs with Ang II, SYB, and Bcl-2 siRNA, and determined NADPH oxidase activity and ROS levels. Furthermore, cellular and mitochondrial physiological states were evaluated, and the expression levels ofmore » target proteins were analyzed. Ang II significantly enhanced intracellular ROS levels, caused mitochondrial membrane dysfunction, and decreased cell viability, leading to apoptosis. This was associated with increased expression of AT1R and p22{sup phox}, increased NADPH oxidase activity, and an increased ratio of Bax/Bcl-2, leading to decreases in antioxidant enzyme activities, which were further strengthened after blocking Bcl-2. Compared to Ang II treatment alone, co-treatment with SYB significantly reversed HUVEC injury. Taken together, these results demonstrate that SYB could significantly protect endothelial cells from Ang II-induced cell damage, and that it does so by upregulating Bcl-2 expression and inhibiting ROS generation. - Highlights: • Angiotensin II depresses mitochondria physiological function. • Angiotensin II activates NADPH oxidase via up-regulating expresion of p22{sup phox}. • Bcl-2 plays a pivotal role in improving mitochondria function and regulates ROS level. • Inhibitor of Bcl-2 promotes angiotensin II mediated HUVEC injury. • SYB attenuates angiotensin II mediated HUVEC injury via up regulating Bcl-2 expression.« less

Identification of LMO2 transcriptome and interactome in diffuse large B-cell lymphoma

PubMed Central

Cubedo, Elena; Gentles, Andrew J.; Huang, Chuanxin; Natkunam, Yasodha; Bhatt, Shruti; Lu, Xiaoqing; Jiang, Xiaoyu; Romero-Camarero, Isabel; Freud, Aharon; Zhao, Shuchun; Bacchi, Carlos E.; Martínez-Climent, Jose A.; Sánchez-García, Isidro; Melnick, Ari

2012-01-01

LMO2 regulates gene expression by facilitating the formation of multipartite DNA-binding complexes. In B cells, LMO2 is specifically up-regulated in the germinal center (GC) and is expressed in GC-derived non-Hodgkin lymphomas. LMO2 is one of the most powerful prognostic indicators in diffuse large B-cell (DLBCL) patients. However, its function in GC B cells and DLBCL is currently unknown. In this study, we characterized the LMO2 transcriptome and transcriptional complex in DLBCL cells. LMO2 regulates genes implicated in kinetochore function, chromosome assembly, and mitosis. Overexpression of LMO2 in DLBCL cell lines results in centrosome amplification. In DLBCL, the LMO2 complex contains some of the traditional partners, such as LDB1, E2A, HEB, Lyl1, ETO2, and SP1, but not TAL1 or GATA proteins. Furthermore, we identified novel LMO2 interacting partners: ELK1, nuclear factor of activated T-cells (NFATc1), and lymphoid enhancer-binding factor1 (LEF1) proteins. Reporter assays revealed that LMO2 increases transcriptional activity of NFATc1 and decreases transcriptional activity of LEF1 proteins. Overall, our studies identified a novel LMO2 transcriptome and interactome in DLBCL and provides a platform for future elucidation of LMO2 function in GC B cells and DLBCL pathogenesis. PMID:22517897

EBV-associated but HHV8-unrelated double-hit effusion-based lymphoma.

PubMed

Chen, Bo-Jung; Chen, David Yen-Ting; Kuo, Chun-Chi; Chuang, Shih-Sung

2017-03-01

Effusion-based lymphoma is a rare and unique type of large B-cell lymphoma presenting in effusion without a mass lesion. It shares many clinicopathological features with primary effusion lymphoma (PEL), but is distinct from PEL by the absence of HHV8 association. Double hit lymphoma (DHL) is an aggressive B-cell lymphoma, defined by concurrent rearrangement of MYC and BCL2 or BCL6. DHL often presents as lymphadenopathy or an extranodal mass, but rarely occurs in effusion. Here we report a 61-year-old male with alcoholic cirrhosis presenting as massive ascites and left pleural effusion. He has no HIV, HBV or HCV infection and no mass lesion by CT scans. Cytology of both pleural effusion and ascites show large lymphoma cells with plasmablastic morphology characterized by pleomorphic and eccentric nuclei, prominent nucleoli and frequent mitoses. Immunohistochemical study with cell block shows that the lymphoma cells express plasma cell-related markers (CD138, MUM-1 and EMA), but not CD3, CD30, CD45, B-cell markers (CD19, CD20, CD79a, and PAX5), HHV8, ALK or cytokeratin. EBER is positive in most lymphoma cells. Fluorescence in situ hybridization reveals rearrangement at the IGH, BCL2, and MYC loci, but not at BCL6. It is diagnosed as an EBV-associated but HHV8-unrelated double hit effusion-based lymphoma with plasmablastic features. The patient passed away soon after diagnosis without chemotherapy. This is the first reported case of double-hit effusion-based lymphoma with MYC and BCL2 rearrangement. This case illustrates the importance of integrating clinical, cytological, immunophenotypical, and molecular findings to reach a correct diagnosis. Diagn. Cytopathol. 2017;45:257-261. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Isolated orbital mass as the primary presentation of a triple-hit lymphoma transformed from a systemic follicular lymphoma.

PubMed

Zhou, Xiao Yi; Lu, Xinyan; Raparia, Kirtee; Chen, Yi-Hua

2018-06-01

Triple-hit lymphoma is a highly aggressive B-cell lymphoma. We report a case of triple-hit lymphoma transformed from systemic follicular lymphoma (FL) after 9-year remission and presented primarily as an isolated orbital mass without systemic symptoms or lymphadenopathy. A 58-year-old female presented with intermittent vertical binocular diplopia, left upper eyelid swelling and pain and was found to have a 2.9 cm orbital mass. Histological section revealed a CD10-positive large B-cell lymphoma, consistent with transformation of FL. Fluorescent in situ hybridization (FISH) analysis demonstrated rearrangements involving C-MYC, BCL-2 and BCL-6 genes, indicating a high grade, triple-hit lymphoma. Triple-hit lymphoma transformed from a low-grade lymphoma may initially present as an isolated orbital mass without systemic evidence of transformation. Early recognition of double or triple-hit lymphomas is important since these patients require aggressive chemotherapy.

BCL2 genotypes and prostate cancer survival.

PubMed

Renner, Wilfried; Langsenlehner, Uwe; Krenn-Pilko, Sabine; Eder, Petra; Langsenlehner, Tanja

2017-06-01

The antiapoptotic B‑cell lymphoma 2 (BCL2) gene is a key player in cancer development and progression. A functional single-nucleotide polymorphism (c.-938C>A, rs2279115) in the inhibitory P2 BCL2 gene promoter has been associated with clinical outcomes in various types of cancer. Aim of the present study was to analyze the role of BCL2-938C>A genotypes in prostate cancer mortality. The association between BCL2-938C>A (rs2279115) genotypes and prostate cancer outcome was studied within the prospective PROCAGENE study comprising 702 prostate cancer patients. During a median follow-up time of 92 months, 120 (17.1%) patients died. A univariate Cox regression model showed a significant association of the CC genotype with reduced cancer-specific survival (CSS; hazard ratio, HR, 2.13, 95% confidence interval, CI, 1.10-4.12; p = 0.024) and overall survival (OS; HR 2.34, 95% CI 1.58-3.47; p < 0.001). In a multivariate Cox regression model including age at diagnosis, risk group, and androgen deprivation therapy, the CC genotype remained a significant predictor of poor CSS (HR 2.05, 95% CI 1.05-3.99; p = 0.034) and OS (HR 2.25, 95% CI 1.51-3.36; p < 0.001). This study provides evidence that the homozygous BCL2-938 CC genotype is associated with OS and C in prostate cancer patients.

Genetically Engineered Lymphocytes, Cyclophosphamide, and Aldesleukin in Treating Patients With Relapsed or Refractory Mantle Cell Lymphoma or Indolent B-Cell Non-Hodgkin Lymphoma

ClinicalTrials.gov

2014-08-04

B-cell Chronic Lymphocytic Leukemia; Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Splenic Marginal Zone Lymphoma; Waldenström Macroglobulinemia

Rare transformation to double hit lymphoma in Waldenstrom's macroglobulinemia.

PubMed

Okolo, Onyemaechi N; Johnson, Ariel C; Yun, Seongseok; Arnold, Stacy J; Anwer, Faiz

2017-08-01

Waldenström macroglobulinemia (WM) is a lymphoproliferative lymphoma that is characterized by monoclonal immunoglobulin M (IgM) protein and bone marrow infiltration. Its incidence is rare and rarer still is its ability to transform to a B-cell lymphoma, particularly the aggressive diffuse large B-cell lymphoma, which bodes a poor prognosis. When transformation includes mutations of MYC, BCL-2 and/or BCL-6, it is known as a 'double hit' or 'triple hit' lymphoma respectively. This paper presents a rare case of WM with mutations positive for MYC and BCL2, making it a case of double hit B-cell lymphoplasmacytic lymphoma with plasmatic differentiation without morphological transformation to aggressive histology like DLBCL. The paper also broadens to include discussions on current topics in the classification, diagnosis, possible causes of transformation, and treatment of WM, including transformation to double hit lymphoma. The significance of this case lies in that the presence of double hit lymphoma-like genetic mutations in WM have not been previously described in the literature and potentially such changes are harbinger of extra-nodal presentation, aggressive growth, and possibly poor prognosis, if data from other double-hit lymphoma are extrapolated.

Alisertib in Combination With Vorinostat in Treating Patients With Relapsed or Recurrent Hodgkin Lymphoma, B-Cell Non-Hodgkin Lymphoma, or Peripheral T-Cell Lymphoma

ClinicalTrials.gov

2018-04-10

Adult B Acute Lymphoblastic Leukemia; Adult T Acute Lymphoblastic Leukemia; Anaplastic Large Cell Lymphoma; Angioimmunoblastic T-Cell Lymphoma; Chronic Lymphocytic Leukemia; Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue; Hepatosplenic T-Cell Lymphoma; Intraocular Lymphoma; Lymphomatous Involvement of Non-Cutaneous Extranodal Site; Mature T-Cell and NK-Cell Non-Hodgkin Lymphoma; Nodal Marginal Zone Lymphoma; Primary Cutaneous B-Cell Non-Hodgkin Lymphoma; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Hodgkin Lymphoma; Recurrent Adult Immunoblastic Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Adult T-Cell Leukemia/Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Mycosis Fungoides and Sezary Syndrome; Recurrent Non-Hodgkin Lymphoma; Recurrent Primary Cutaneous T-Cell Non-Hodgkin Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hairy Cell Leukemia; Small Intestinal Lymphoma; Splenic Marginal Zone Lymphoma; T-Cell Large Granular Lymphocyte Leukemia; Testicular Lymphoma; Waldenstrom Macroglobulinemia

Bcl-2 silencing attenuates hypoxia-induced apoptosis resistance in pulmonary microvascular endothelial cells.

PubMed

Cao, Yongmei; Jiang, Zhen; Zeng, Zhen; Liu, Yujing; Gu, Yuchun; Ji, Yingying; Zhao, Yupeng; Li, Yingchuan

2016-01-01

Pulmonary arterial hypertension (PAH) is a life-threatening disorder that ultimately causes heart failure. While the underlying causes of this condition are not well understood, previous studies suggest that the anti-apoptotic nature of pulmonary microvascular endothelial cells (PMVECs) in hypoxic environments contributes to PAH pathogenesis. In this study, we focus on the contribution of Bcl-2 and hypoxia response element (HRE) to apoptosis-resistant endothelial cells and investigate the mechanism. PMVECs obtained from either normal rats or apoptosis-resistant PMVECs obtained from PAH rats were transduced with recombinant lentiviral vectors carrying either Bcl-2-shRNA or HRE combined Bcl-2-shRNA, and then cultured these cells for 24 h under hypoxic (5% O2) or normoxic (21% O2) conditions. In normal PMVECs, Bcl-2-shRNA or HRE combined with Bcl-2-shRNA transduction successfully decreased Bcl-2 expression, while increasing apoptosis as well as caspase-3 and P53 expression in a normoxic environment. In a hypoxic environment, the effects of Bcl-2-shRNA treatment on cell apoptosis, and on Bcl-2, caspase-3, P53 expression were significantly suppressed. Conversely, HRE activation combined with Bcl-2-shRNA transduction markedly enhanced cell apoptosis and upregulated caspase-3 and P53 expression, while decreasing Bcl-2 expression. Furthermore, in apoptosis-resistant PMVECs, HRE-mediated Bcl-2 silencing effectively enhanced cell apoptosis and caspase-3 activity. The apoptosis rate was significantly depressed when Lv-HRE-Bcl-2-shRNA was combined with Lv-P53-shRNA or Lv-caspase3-shRNA transduction in a hypoxic environment. These results suggest that HRE-mediated Bcl-2 inhibition can effectively attenuate hypoxia-induced apoptosis resistance in PMVECs by downregulating Bcl-2 expression and upregulating caspase-3 and P53 expression. This study therefore reveals critical insight into potential therapeutic targets for treating PAH.

A Potent and Highly Efficacious Bcl-2/Bcl-xL Inhibitor

PubMed Central

McEachern, Donna; Yang, Chao-Yie; Meagher, Jennifer; Stuckey, Jeanne; Wang, Shaomeng

2013-01-01

Our previously reported Bcl-2/Bcl-xL inhibitor, 4, effectively inhibited tumor growth but failed to achieve complete regression in vivo. We have now performed extensive modifications on its pyrrole core structure, which has culminated in the discovery of 32 (BM-1074). Compound 32 binds to Bcl-2 and Bcl-xL proteins with Ki values of < 1 nM and inhibits cancer cell growth with IC50 values of 1-2 nM in four small-cell lung cancer cell lines sensitive to potent and specific Bcl-2/Bcl-xL inhibitors. Compound 32 is capable of achieving rapid, complete and durable tumor regression in vivo at a well-tolerated dose-schedule. Compound 32 is the most potent and efficacious Bcl-2/Bcl-xL inhibitor reported to date. PMID:23448298

Primary central nervous system diffuse large B-cell lymphoma in the immunocompetent: Immunophenotypic subtypes and Epstein-Barr virus association.

PubMed

Mahadevan, Anita; Rao, Clementina Rama; Shanmugham, M; Shankar, Susarla Krishna

2015-01-01

Primary central nervous system diffuse large B-cell lymphoma (PCNSL DLBCL) in the immunocompetent is an uncommon tumor that has an activated B-cell immunophenotype resembling germinal center exit B cells. They also differ from primary central nervous diffuse large B-cell lymphomas in the immunocompromised as they show no association with the Epstein-Barr virus. To determine if immunophenotypic subtyping of PCNS DLBCL from Asian subcontinent are also different similar to its systemic counterpart is unclear, as there are only limited studies from Asia, and none from India. The immunohistochemical profile of 24 South Indian patients with primary central nervous system diffuse large B-cell lymphoma was studied using germinal center markers - CD10 and Bcl-6, and activation markers - MUM1 and CD138, which are markers for late/post germinal centre B cells. Insitu hybridization for EBV genome and LMP1 by immunohistochemistry was carried out in all cases to determine association with EBV. Centroblastic morphology and uniform activated B-cell phenotype with positivity for MUM1 was seen in 91.6% of tumors. Co-expression of Bcl-6 and MUM1 was evident in 50%, which is more frequent than in systemic diffuse large B-cell lymphomas. All cases were negative for Epstein-Barr virus using EBER in-situ hybridization and LMP1 immunohistochemistry. Primary diffuse large B-cell lymphoma in the immunocompetent is a distinct clinicopathological entity with centroblastic morphology, a uniform activated B-cell immunophenotype that is not associated with the Epstein-Barr virus regardless of geographic origin.

Micro-Economics of Apoptosis in Cancer: ncRNAs Modulation of BCL-2 Family Members

PubMed Central

Villanova, Lidia; Careccia, Silvia; De Maria, Ruggero

2018-01-01

In the last few years, non-coding RNAs (ncRNAs) have been a hot topic in cancer research. Many ncRNAs were found to regulate the apoptotic process and to play a role in tumor cell resistance to treatment. The apoptotic program is on the frontline as self-defense from cancer onset, and evasion of apoptosis has been classified as one of the hallmarks of cancer responsible for therapy failure. The B-cell lymphoma 2 (BCL-2) family members are key players in the regulation of apoptosis and mediate the activation of the mitochondrial death machinery in response to radiation, chemotherapeutic agents and many targeted therapeutics. The balance between the pro-survival and the pro-apoptotic BCL-2 proteins is strictly controlled by ncRNAs. Here, we highlight the most common mechanisms exerted by microRNAs, long non-coding RNAs and circular RNAs on the main mediators of the intrinsic apoptotic cascade with particular focus on their significance in cancer biology. PMID:29570632

Micro-Economics of Apoptosis in Cancer: ncRNAs Modulation of BCL-2 Family Members.

PubMed

Villanova, Lidia; Careccia, Silvia; De Maria, Ruggero; Fiori, Micol E

2018-03-23

In the last few years, non-coding RNAs (ncRNAs) have been a hot topic in cancer research. Many ncRNAs were found to regulate the apoptotic process and to play a role in tumor cell resistance to treatment. The apoptotic program is on the frontline as self-defense from cancer onset, and evasion of apoptosis has been classified as one of the hallmarks of cancer responsible for therapy failure. The B-cell lymphoma 2 (BCL-2) family members are key players in the regulation of apoptosis and mediate the activation of the mitochondrial death machinery in response to radiation, chemotherapeutic agents and many targeted therapeutics. The balance between the pro-survival and the pro-apoptotic BCL-2 proteins is strictly controlled by ncRNAs. Here, we highlight the most common mechanisms exerted by microRNAs, long non-coding RNAs and circular RNAs on the main mediators of the intrinsic apoptotic cascade with particular focus on their significance in cancer biology.

Ascites as the initial characteristic manifestation in a patient with primary gastric CD8-positive diffuse large B-cell lymphoma.

PubMed

Zhao, K-X; Dai, G-Z; Zhu, J-F

2016-05-01

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy and the most common type of non-Hodgkin's lymphomas, the stomach is the most common extranodal site. Gastric DLBCL is often characterized by epigastric pain and vomiting. We report a case of a 78-year-old female patient with gastric diffuse large B-cell lymphoma (DLBCL) with high CD8 level which was initially manifested with ascites of unknown origin. The patient was admitted with a chief complaint of abdominal distension and scanty urine over the last twenty days, while without anorexia and fatigue until 15 March. She had no history of viral hepatitis, tuberculosis, schistosomiasis. Laboratory data revealed normal aminotransferases and bilirubin levels, but serum lactate dehydrogenase, CA125, ascitic fluid lactate dehydrogenase, ascitic fluid lymphocytes increased. The ascitic fluid was yellow-colored with 98.5% lymphocytes. Stool occult blood test was positive. Upper gastrointestinal endoscopy performed a few days later revealed multiple gastric crateriform ulcers, and Helicobacter pylori was detected in the biopsy specimen. Peripheral blood CD8+ was increased by 51%. Pathology test showed lymphocytes with atypical hyperplasia, and immunohistochemistry test resulted CD20+, CD10-, CD79α+, κ+, bcl-6+, Ki-67+ (approximately 95%), λ-, bcl-2-, CD3-, CD43-. Immunoglobulin gene (Ig) clonal rearrangement showed IgH: FR1 (+), FR2 (+), FR3(-), Igk: VJ(+), Vkde (+) in lymphoma tissue. The features of histopathology and immunohistochemistry of the tissue confirmed diffuse large B-cell lymphoma (DLBL). The patient received an uncompleted CHOP program combined with H. pylori eradication. However, the patient deceased due to disease development sixteen days later after the diagnosis.

Overexpression of B7-H3 augments anti-apoptosis of colorectal cancer cells by Jak2-STAT3.

PubMed

Zhang, Ting; Jiang, Bo; Zou, Shi-Tao; Liu, Fen; Hua, Dong

2015-02-14

To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms. SW620 cells that highly overexpressed B7-H3 (SW620-B7-H3-EGFP) and HCT8 cells stably transfected with B7-H3 shRNA (HCT8-shB7-H3) were previously constructed in our laboratory. Cells transfected with pIRES2-EGFP were used as negative controls (SW620-NC and HCT8-NC). Real-time PCR and western blotting analysis were used to detect the mRNA and protein expressions of the apoptosis regulator proteins Bcl-2, Bcl-xl and Bax. A cell proliferation assay was used to evaluate the survival rate and drug sensitivity of the cells. The effect of drug resistance was detected by a cell cycle assay. Active caspase-3 western blotting was used to reflect the anti-apoptotic ability of cells. Western blotting was also performed to determine the expression of proteins associated with the Jak2-STAT3 signaling pathway and the apoptosis regulator proteins after the treatment with AG490, a Jak2 specific inhibitor, in B7-H3 overexpressing cells. The data were analyzed by GraphPad Prism 6 using a non-paired t-test. Whether by overexpression in SW620 cells or downregulation in HCT8, B7-H3 significantly affected the expression of anti- and pro-apoptotic proteins, at both the transcriptional and translational levels, compared with the negative control (P < 0.05). A cell proliferation assay revealed that B7-H3 overexpression increased the drug resistance of cells and resulted in a higher survival rate (P < 0.05). In addition, the results of cell cycle and active caspase-3 western blotting proved that B7-H3 overexpression inhibited apoptosis in colorectal cancer cell lines (P < 0.05). B7-H3 overexpression improved Jak2 and STAT3 phosphorylation and, in turn, increased the expression of the downstream anti-apoptotic proteins B-cell CLL/lymphoma 2 (Bcl-2) and Bcl-xl, based on western blotting (P < 0.05). After treating B7-H3 overexpressing cells with the Jak2

ATP promotes cell survival via regulation of cytosolic [Ca2+] and Bcl-2/Bax ratio in lung cancer cells

PubMed Central

Song, Shanshan; Jacobson, Krista N.; McDermott, Kimberly M.; Reddy, Sekhar P.; Cress, Anne E.; Tang, Haiyang; Dudek, Steven M.; Black, Stephen M.; Garcia, Joe G. N.; Makino, Ayako

2015-01-01

Adenosine triphosphate (ATP) is a ubiquitous extracellular messenger elevated in the tumor microenvironment. ATP regulates cell functions by acting on purinergic receptors (P2X and P2Y) and activating a series of intracellular signaling pathways. We examined ATP-induced Ca2+ signaling and its effects on antiapoptotic (Bcl-2) and proapoptotic (Bax) proteins in normal human airway epithelial cells and lung cancer cells. Lung cancer cells exhibited two phases (transient and plateau phases) of increase in cytosolic [Ca2+] ([Ca2+]cyt) caused by ATP, while only the transient phase was observed in normal cells. Removal of extracellular Ca2+ eliminated the plateau phase increase of [Ca2+]cyt in lung cancer cells, indicating that the plateau phase of [Ca2+]cyt increase is due to Ca2+ influx. The distribution of P2X (P2X1-7) and P2Y (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11) receptors was different between lung cancer cells and normal cells. Proapoptotic P2X7 was nearly undetectable in lung cancer cells, which may explain why lung cancer cells showed decreased cytotoxicity when treated with high concentration of ATP. The Bcl-2/Bax ratio was increased in lung cancer cells following treatment with ATP; however, the antiapoptotic protein Bcl-2 demonstrated more sensitivity to ATP than proapoptotic protein Bax. Decreasing extracellular Ca2+ or chelating intracellular Ca2+ with BAPTA-AM significantly inhibited ATP-induced increase in Bcl-2/Bax ratio, indicating that a rise in [Ca2+]cyt through Ca2+ influx is the critical mediator for ATP-mediated increase in Bcl-2/Bax ratio. Therefore, despite high ATP levels in the tumor microenvironment, which would induce cell apoptosis in normal cells, the decreased P2X7 and elevated Bcl-2/Bax ratio in lung cancer cells may enable tumor cells to survive. Increasing the Bcl-2/Bax ratio by exposure to high extracellular ATP may, therefore, be an important selective pressure promoting transformation and cancer progression. PMID:26491047

LDR reverses DDP resistance in ovarian cancer cells by affecting ERCC-1, Bcl-2, Survivin and Caspase-3 expressions.

PubMed

Ju, Xingyan; Yu, Hongsheng; Liang, Donghai; Jiang, Tao; Liu, Yuanwei; Chen, Ling; Dong, Qing; Liu, Xiaoran

2018-06-01

Ovarian cancer is the most frequent cause of death resulting from malignant gynecological tumors. After surgical intervention, cisplatin (DDP) is a major chemotherapy drug for ovarian cancer, but the ovarian cancer cells tend to develop DDP resistance in the clinical setting. Tumor cells are sensitive to low-dose radiation (LDR). However, how the LDR therapy improves the effects of chemotherapy drugs on ovarian cancer is not well understood. This study aimed to explore this issue. The SKOV3/DDP cells were divided into 3 groups, including low-dose group, conventional-dose group, and control group (no radiation). Cell counting kit-8 assay was performed to measure cell proliferation. Flow cytometric analysis was then utilized to quantify the apoptosis with classical Annexin V/propidium iodide co-staining. And Real-time quantitative PCR and western blot were eventually used to analyze the mRNA and protein levels of excision repair cross complementing-group 1 (ERCC1), B-cell lymphoma 2 (Bcl-2), Survivin and Caspase-3, respectively. The IC50 value of DDP in the low-dose group was significantly lower compared with the other two groups. Compared with the conventional-dose group and control group, LDR treatment resulted in significantly more apoptosis. Besides, LDR treatment significantly decreased the mRNA and protein expression of ERCC1, Bcl-2, and Survivin, and enhanced the mRNA and protein expression of Caspase-3 compared with the other two groups. LDR reversed DDP resistance in SKOV3/DDP cells possibly by suppressing ERCC1, Bcl-2, and Survivin expressions, and increasing Caspase-3 expression. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Hypoxia promotes apoptosis of neuronal cells through hypoxia-inducible factor-1α-microRNA-204-B-cell lymphoma-2 pathway

PubMed Central

Wang, Xiuwen; Li, Ji; Wu, Dongjin; Bu, Xiangpeng

2015-01-01

Neuronal cells are highly sensitive to hypoxia and may be subjected to apoptosis when exposed to hypoxia. Several apoptosis-related genes and miRNAs involve in hypoxia-induced apoptosis. This study aimed to examine the role of HIF1α-miR-204-BCL-2 pathway in hypoxia-induced apoptosis in neuronal cells. Annexin V/propidium iodide assay was performed to analyze cell apoptosis in AGE1.HN and PC12 cells under hypoxic or normoxic conditions. The expression of BCL-2 and miR-204 were determined by Western blot and qRT-PCR. The effects of miR-204 overexpression or knockdown on the expression of BCL-2 were evaluated by luciferase assay and Western blot under hypoxic or normoxic conditions. HIF-1α inhibitor YC-1 and siHIF-1α were employed to determine the effect of HIF-1α on the up-regulation of miR-204 and down-regulation of BCL-2 induced by hypoxia. Apoptosis assay showed the presence of apoptosis induced by hypoxia in neuronal cells. Moreover, we found that hypoxia significantly down-regulated the expression of BCL-2, and increased the mRNA level of miR-204 in neuronal cells than that in control. Bioinformatic analysis and luciferase reporter assay demonstrated that miR-204 directly targeted and regulated the expression of BCL-2. Specifically, the expression of BCL-2 was inhibited by miR-204 mimic and enhanced by miR-204 inhibitor. Furthermore, we detected that hypoxia induced cell apoptosis via HIF-1α/miR-204/BCL-2 in neuronal cells. This study demonstrated that HIF-1α-miR-204-BCL-2 pathway contributed to apoptosis of neuronal cells induced by hypoxia, which could potentially be exploited to prevent spinal cord ischemia–reperfusion injury. PMID:26350953

Immunoblot analysis of cellular expression of Bcl-2 family proteins, Bcl-2, Bax, Bcl-X and Mcl-1, in human peripheral blood and lymphoid tissues.

PubMed

Ohta, K; Iwai, K; Kasahara, Y; Taniguchi, N; Krajewski, S; Reed, J C; Miyawaki, T

1995-11-01

The ability of Bcl-2 to inhibit apoptotic cell death is well established. Several homologues of the bcl-2 gene, such as bax, bcl-x or mcl-1, have recently been identified. Like Bcl-2, both Bcl-XL and Mcl-1 appear to function as repressors of apoptotic cell death, whereas Bax facilitates it, indicating possible interactions among them in the control of cellular survival. To investigate the in vivo role of expression of bcl-2 gene family products, immunoblot analysis using corresponding specific antisera was performed for peripheral blood cells and some lymphoid tissues in humans. We demonstrated that all Bcl-2 family proteins were expressed at various levels in hematolymphoid cell subpopulations isolated from peripheral blood, tonsil, spleen and thymus. Lymphoid expression of Bcl-2 family proteins tended to increase following activation, but declined with time in culture. Loss of Bcl-2 in cultured lymphoid cells was especially marked. Sole expression of Bax, but not other members of the Bcl-2 family, was observed on neutrophils, seemingly reflecting their shortest life-span among blood leukocytes. The results support the notion that a balance of expression of Bcl-2 family proteins may regulate the life and death of hematolymphoid cells at different stages of cell differentiation and activation.

Exploring the conformational and binding properties of unphosphorylated/phosphorylated monomeric and trimeric Bcl-2 through docking and molecular dynamics simulations.

PubMed

Zacarías-Lara, Oscar J; Correa-Basurto, José; Bello, Martiniano

2016-07-01

B-cell lymphoma (Bcl-2) is commonly associated with the progression and preservation of cancer and certain lymphomas; therefore, it is considered as a biological target against cancer. Nevertheless, evidence of all its structural binding sites has been hidden because of the lack of a complete Bcl-2 model, given the presence of a flexible loop domain (FLD), which is responsible for its complex behavior. FLD region has been implicated in phosphorylation, homotrimerization, and heterodimerization associated with Bcl-2 antiapoptotic function. In this contribution, homology modeling, molecular dynamics (MD) simulations in the microsecond (µs) time-scale and docking calculations were combined to explore the conformational complexity of unphosphorylated/phosphorylated monomeric and trimeric Bcl-2 systems. Conformational ensembles generated through MD simulations allowed for identifying the most populated unphosphorylated/phosphorylated monomeric conformations, which were used as starting models to obtain trimeric complexes through protein-protein docking calculations, also submitted to µs MD simulations. Principal component analysis showed that FLD represents the main contributor to total Bcl-2 mobility, and is affected by phosphorylation and oligomerization. Subsequently, based on the most representative unphosphorylated/phosphorylated monomeric and trimeric Bcl-2 conformations, docking studies were initiated to identify the ligand binding site of several known Bcl-2 inhibitors to explain their influence in homo-complex formation and phosphorylation. Docking studies showed that the different conformational states experienced by FLD, such as phosphorylation and oligomerization, play an essential role in the ability to make homo and hetero-complexes. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 393-413, 2016. © 2016 Wiley Periodicals, Inc.

Expression Profile of BCL-2, BCL-XL, and MCL-1 Predicts Pharmacological Response to the BCL-2 Selective Antagonist Venetoclax in Multiple Myeloma Models.

PubMed

Punnoose, Elizabeth A; Leverson, Joel D; Peale, Franklin; Boghaert, Erwin R; Belmont, Lisa D; Tan, Nguyen; Young, Amy; Mitten, Michael; Ingalla, Ellen; Darbonne, Walter C; Oleksijew, Anatol; Tapang, Paul; Yue, Peng; Oeh, Jason; Lee, Leslie; Maiga, Sophie; Fairbrother, Wayne J; Amiot, Martine; Souers, Andrew J; Sampath, Deepak

2016-05-01

BCL-2 family proteins dictate survival of human multiple myeloma cells, making them attractive drug targets. Indeed, multiple myeloma cells are sensitive to antagonists that selectively target prosurvival proteins such as BCL-2/BCL-XL (ABT-737 and ABT-263/navitoclax) or BCL-2 only (ABT-199/GDC-0199/venetoclax). Resistance to these three drugs is mediated by expression of MCL-1. However, given the selectivity profile of venetoclax it is unclear whether coexpression of BCL-XL also affects antitumor responses to venetoclax in multiple myeloma. In multiple myeloma cell lines (n = 21), BCL-2 is expressed but sensitivity to venetoclax correlated with high BCL-2 and low BCL-XL or MCL-1 expression. Multiple myeloma cells that coexpress BCL-2 and BCL-XL were resistant to venetoclax but sensitive to a BCL-XL-selective inhibitor (A-1155463). Multiple myeloma xenograft models that coexpressed BCL-XL or MCL-1 with BCL-2 were also resistant to venetoclax. Resistance to venetoclax was mitigated by cotreatment with bortezomib in xenografts that coexpressed BCL-2 and MCL-1 due to upregulation of NOXA, a proapoptotic factor that neutralizes MCL-1. In contrast, xenografts that expressed BCL-XL, MCL-1, and BCL-2 were more sensitive to the combination of bortezomib with a BCL-XL selective inhibitor (A-1331852) but not with venetoclax cotreatment when compared with monotherapies. IHC of multiple myeloma patient bone marrow biopsies and aspirates (n = 95) revealed high levels of BCL-2 and BCL-XL in 62% and 43% of evaluable samples, respectively, while 34% were characterized as BCL-2(High)/BCL-XL (Low) In addition to MCL-1, our data suggest that BCL-XL may also be a potential resistance factor to venetoclax monotherapy and in combination with bortezomib. Mol Cancer Ther; 15(5); 1132-44. ©2016 AACR. ©2016 American Association for Cancer Research.

Xanthorrhizol induced DNA fragmentation in HepG2 cells involving Bcl-2 family proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tee, Thiam-Tsui, E-mail: thiamtsu@yahoo.com; Cheah, Yew-Hoong; Bioassay Unit, Herbal Medicine Research Center, Institute for Medical Research, Jalan Pahang, Kuala Lumpur

Highlights: Black-Right-Pointing-Pointer We isolated xanthorrhizol, a sesquiterpenoid compound from Curcuma xanthorrhiza. Black-Right-Pointing-Pointer Xanthorrhizol induced apoptosis in HepG2 cells as observed using SEM. Black-Right-Pointing-Pointer Apoptosis in xanthorrhizol-treated HepG2 cells involved Bcl-2 family proteins. Black-Right-Pointing-Pointer DNA fragmentation was observed in xanthorrhizol-treated HepG2 cells. Black-Right-Pointing-Pointer DNA fragmentation maybe due to cleavage of PARP and DFF45/ICAD proteins. -- Abstract: Xanthorrhizol is a plant-derived pharmacologically active sesquiterpenoid compound isolated from Curcuma xanthorrhiza. Previously, we have reported that xanthorrhizol inhibited the proliferation of HepG2 human hepatoma cells by inducing apoptotic cell death via caspase activation. Here, we attempt to further elucidate the mode of action ofmore » xanthorrhizol. Apoptosis in xanthorrhizol-treated HepG2 cells as observed by scanning electron microscopy was accompanied by truncation of BID; reduction of both anti-apoptotic Bcl-2 and Bcl-X{sub L} expression; cleavage of PARP and DFF45/ICAD proteins and DNA fragmentation. Taken together, these results suggest xanthorrhizol as a potent antiproliferative agent on HepG2 cells by inducing apoptosis via Bcl-2 family members. Hence we proposed that xanthorrhizol could be used as an anti-liver cancer drug for future studies.« less

Rituximab and Interleukin-12 in Treating Patients With B-Cell Non-Hodgkin's Lymphoma

ClinicalTrials.gov

2013-08-23

Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue; Nodal Marginal Zone B-cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma

Transformation of follicular lymphoma to plasmablastic lymphoma with c-myc gene rearrangement.

PubMed

Ouansafi, Ihsane; He, Bing; Fraser, Cory; Nie, Kui; Mathew, Susan; Bhanji, Rumina; Hoda, Rana; Arabadjief, Melissa; Knowles, Daniel; Cerutti, Andrea; Orazi, Attilio; Tam, Wayne

2010-12-01

Follicular lymphoma (FL) is an indolent lymphoma that transforms to high-grade lymphoma, mostly diffuse large B-cell lymphoma, in about a third of patients. We present the first report of a case of FL that transformed to plasmablastic lymphoma (PBL). Clonal transformation of the FL to PBL was evidenced by identical IGH/BCL2 gene rearrangements and VDJ gene usage in rearranged IGH genes. IGH/ BCL2 translocation was retained in the PBL, which also acquired c-myc gene rearrangement. Genealogic analysis based on somatic hypermutation of the rearranged IGH genes of both FL and PBL suggests that transformation of the FL to PBL occurred most likely by divergent evolution from a common progenitor cell rather than direct evolution from the FL clone. Our study of this unusual case expands the histologic spectrum of FL transformation and increases our understanding of the pathogenetic mechanisms of transformation of indolent lymphomas to aggressive lymphomas.

Prognostic Significance of Diffuse Large B-Cell Lymphoma Cell of Origin Determined by Digital Gene Expression in Formalin-Fixed Paraffin-Embedded Tissue Biopsies

PubMed Central

Scott, David W.; Mottok, Anja; Ennishi, Daisuke; Wright, George W.; Farinha, Pedro; Ben-Neriah, Susana; Kridel, Robert; Barry, Garrett S.; Hother, Christoffer; Abrisqueta, Pau; Boyle, Merrill; Meissner, Barbara; Telenius, Adele; Savage, Kerry J.; Sehn, Laurie H.; Slack, Graham W.; Steidl, Christian; Staudt, Louis M.; Connors, Joseph M.; Rimsza, Lisa M.; Gascoyne, Randy D.

2015-01-01

Purpose To evaluate the prognostic impact of cell-of-origin (COO) subgroups, assigned using the recently described gene expression–based Lymph2Cx assay in comparison with International Prognostic Index (IPI) score and MYC/BCL2 coexpression status (dual expressers). Patients and Methods Reproducibility of COO assignment using the Lymph2Cx assay was tested employing repeated sampling within tumor biopsies and changes in reagent lots. The assay was then applied to pretreatment formalin-fixed paraffin-embedded tissue (FFPET) biopsies from 344 patients with de novo diffuse large B-cell lymphoma (DLBCL) uniformly treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) at the British Columbia Cancer Agency. MYC and BCL2 protein expression was assessed using immunohistochemistry on tissue microarrays. Results The Lymph2Cx assay provided concordant COO calls in 96% of 49 repeatedly sampled tumor biopsies and in 100% of 83 FFPET biopsies tested across reagent lots. Critically, no frank misclassification (activated B-cell–like DLBCL to germinal center B-cell–like DLBCL or vice versa) was observed. Patients with activated B-cell–like DLBCL had significantly inferior outcomes compared with patients with germinal center B-cell–like DLBCL (log-rank P < .001 for time to progression, progression-free survival, disease-specific survival, and overall survival). In pairwise multivariable analyses, COO was associated with outcomes independent of IPI score and MYC/BCL2 immunohistochemistry. The prognostic significance of COO was particularly evident in patients with intermediate IPI scores and the non–MYC-positive/BCL2-positive subgroup (log-rank P < .001 for time to progression). Conclusion Assignment of DLBCL COO by the Lymph2Cx assay using FFPET biopsies identifies patient groups with significantly different outcomes after R-CHOP, independent of IPI score and MYC/BCL2 dual expression. PMID:26240231

Difficult Diagnosis between B Cell Lymphoma and Classical Hodgkin's Lymphoma.

PubMed

Rentas Torres, Yaixa; Rodríguez-López, Joshua L; Valentin, Maria; Silva, Hector

2015-01-01

Although primary mediastinal large B-cell lymphoma and classic Hodgkin lymphoma of nodular sclerosis type are distinct disease, they share several clinical characteristics and biologic features. However, there are mediastinal lymphomas that not fit in either category. These types of lymphomas are recognized as mediastinal gray zone lymphomas. Gray zone lymphomas are lymphatic tumors that cannot be assigned to a defined lymphoma entity due to morphological, clinical, or genetic reasons. In this report, we present a case of a 22 year-old-Hispanic-female diagnosed with B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Hodgkin lymphoma.

Open-Label, Multicenter, Phase 1/2 Study of Tazemetostat (EZH2 Histone Methyl Transferase [HMT] Inhibitor) as a Single Agent in Subjects With Adv. Solid Tumors or With B-cell Lymphomas and Tazemetostat in Combination With Prednisolone in Subjects With DLBCL

ClinicalTrials.gov

2018-05-31

B-cell Lymphomas (Phase 1); Advanced Solid Tumors (Phase 1); Diffuse Large B-cell Lymphoma (Phase 2); Follicular Lymphoma (Phase 2); Transformed Follicular Lymphoma; Primary Mediastinal Large B-Cell Lymphoma

Identification of three subgroups of B cell chronic lymphocytic leukemia based upon mutations of BCL-6 and IgV genes.

PubMed

Capello, D; Fais, F; Vivenza, D; Migliaretti, G; Chiorazzi, N; Gaidano, G; Ferrarini, M

2000-05-01

Although B cell chronic lymphocytic leukemia (B-CLL) has been traditionally viewed as a tumor of virgin B cells, this notion has been recently questioned by data suggesting that a fraction of B-CLL derives from antigen experienced B cells. In order to further clarify the histogenetic derivation of this lymphoproliferation, we have analyzed the DNA sequences of the 5' non-coding region of BCL-6 proto-oncogene in 28 cases of B-CLL. Mutations of BCL-6 proto-oncogene, a zinc finger transcription factor implicated in lymphoma development, represent a histogenetic marker of B cell transit through the germinal center (GC) and occur frequently in B cell malignancies derived from GC or post-GC B cells. For comparison, the same tumor panel was analyzed for somatic mutations of the rearranged immunoglobulin variable (IgV) genes, which are known to be acquired at the time of B cell transit through the GC. Sequence analyses of BCL-6 and IgV genes allowed the definition of three groups of B-CLL. Group I B-CLL displayed mutations of both BCL-6 and IgV genes (10/28; 36%). Group II B-CLL displayed mutated IgV genes, but a germline BCL-6 gene (5/28; 18%). Finally, group III B-CLL included the remaining cases (13/28; 46%) that were characterized by the absence of somatic mutations of both BCL-6 and IgV genes. Overall, the distribution of BCL-6 and IgV mutations in B-CLL reinforce the notion that this leukemia is histogenetically heterogeneous and that a substantial subgroup of these lymphoproliferations derives from post-germinal center B cells.

Curcumin regulates gene expression of insulin like growth factor, B-cell CLL/lymphoma 2 and antioxidant enzymes in streptozotocin induced diabetic rats

PubMed Central

2013-01-01

Background The effects of curcumin on the activities and gene expression of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione-S-transferase (G-ST), B-cell CLL/lymphoma 2 (Bcl-2) and insulin like growth factor-1 (IGF-1) in diabetic rats were studied. Methods Twenty four rats were assigned to three groups (8 rats for each). Rats of first group were non diabetic and rats of the second group were rendered diabetic by streptozotocin (STZ). Both groups received vehicle, corn oil only (5 ml/kg body weight) and served as negative and positive controls, respectively. Rats of the third group were rendered diabetic and received oral curcumin dissolved in corn oil at a dose of 15 mg/5 ml/kg body weight for 6 weeks. Results Diabetic rats showed significant increase of blood glucose, thiobarbituric acid reactive substances (TBARS) and activities of all antioxidant enzymes with significant reduction of reduced glutathione (GSH) compare to the control non diabetic group. Gene expression of Bcl2, SOD, CAT, GPX and GST was increased significantly in diabetic untreated rats compare to the control non diabetic group. The administration of curcumin to diabetic rats normalized significantly their blood sugar level and TBARS values and increased the activities of all antioxidant enzymes and GSH concentration. In addition, curcumin treated rats showed significant increase in gene expression of IGF-1, Bcl2, SOD and GST compare to non diabetic and diabetic untreated rats. Conclusion Curcumin was antidiabetic therapy, induced hypoglycemia by up-regulation of IGF-1 gene and ameliorate the diabetes induced oxidative stress via increasing the availability of GSH, increasing the activities and gene expression of antioxidant enzymes and Bcl2. Further studies are required to investigate the actual mechanism of action of curcumin regarding the up regulation of gene expression of examined parameters. PMID:24364912

Simultaneous in vitro molecular screening of protein-peptide interactions by flow cytometry, using six Bcl-2 family proteins as examples.

PubMed

Simons, Peter C; Young, Susan M; Carter, Mark B; Waller, Anna; Zhai, Dayong; Reed, John C; Edwards, Bruce S; Sklar, Larry A

2011-06-09

The B-cell lymphoma-2 (Bcl-2) family contains six antiapoptotic members, each with a hydrophobic pocket in which Bcl-2 homology region 3 (BH3) helices bind. This binding quenches apoptotic signals from activated BH3 family members. Many tumor cells either have increased expression of one of these six proteins or become overexpressed under treatment. Six fusion proteins made up of glutathione-S-transferase and each of the Bcl-2 members are bound individually to six glutathione bead sets, each set being easily distinguished by its different intensity of red fluorescence. The coated bead sets are washed, combined and incubated with green fluorescent Bim-BH3 peptide and a small molecule in 10-μl wells for 1 h. The green fluorescence signal for each bead set is resolved, and selective inhibitors are expected to reduce the signal for individual bead sets. Each 384-well plate is analyzed in 12 min, measuring 200 of 2,000 beads (∼10%) of each type per well.

The prognosis of MYC translocation positive diffuse large B-cell lymphoma depends on the second hit.

PubMed

Clipson, Alexandra; Barrans, Sharon; Zeng, Naiyan; Crouch, Simon; Grigoropoulos, Nicholas F; Liu, Hongxiang; Kocialkowski, Sylvia; Wang, Ming; Huang, Yuanxue; Worrillow, Lisa; Goodlad, John; Buxton, Jenny; Neat, Michael; Fields, Paul; Wilkins, Bridget; Grant, John W; Wright, Penny; Ei-Daly, Hesham; Follows, George A; Roman, Eve; Watkins, A James; Johnson, Peter W M; Jack, Andrew; Du, Ming-Qing

2015-07-01

A proportion of MYC translocation positive diffuse large B-cell lymphomas (DLBCL) harbour a BCL2 and/or BCL6 translocation, known as double-hit DLBCL, and are clinically aggressive. It is unknown whether there are other genetic abnormalities that cooperate with MYC translocation and form double-hit DLBCL, and whether there is a difference in clinical outcome between the double-hit DLBCL and those with an isolated MYC translocation. We investigated TP53 gene mutations along with BCL2 and BCL6 translocations in a total of 234 cases of DLBCL, including 81 with MYC translocation. TP53 mutations were investigated by PCR and sequencing, while BCL2 and BCL6 translocation was studied by interphase fluorescence in situ hybridization. The majority of MYC translocation positive DLBCLs (60/81 = 74%) had at least one additional genetic hit. In MYC translocation positive DLBCL treated by R-CHOP ( n  = 67), TP53 mutation and BCL2, but not BCL6 translocation had an adverse effect on patient overall survival. In comparison with DLBCL with an isolated MYC translocation, cases with MYC/TP53 double-hits had the worst overall survival, followed by those with MYC/BCL2 double-hits. In MYC translocation negative DLBCL treated by R-CHOP ( n  = 101), TP53 mutation, BCL2 and BCL6 translocation had no impact on patient survival. The prognosis of MYC translocation positive DLBCL critically depends on the second hit, with TP53 mutations and BCL2 translocation contributing to an adverse prognosis. It is pivotal to investigate both TP53 mutations and BCL2 translocations in MYC translocation positive DLBCL, and to distinguish double-hit DLBCLs from those with an isolated MYC translocation.

Frequent downregulation of BTB and CNC homology 2 expression in Epstein-Barr virus-positive diffuse large B-cell lymphoma.

PubMed

Noujima-Harada, Mai; Takata, Katsuyoshi; Miyata-Takata, Tomoko; Sakurai, Hiroaki; Igarashi, Kazuhiko; Ito, Etsuro; Nagakita, Keina; Taniguchi, Kohei; Ohnishi, Nobuhiko; Omote, Shizuma; Tabata, Tetsuya; Sato, Yasuharu; Yoshino, Tadashi

2017-05-01

Diffuse large B-cell lymphoma (DLBCL) is the most common B-cell lymphoma subtype, and the Epstein-Barr virus (EBV)-positive subtype of DLBCL is known to show a more aggressive clinical behavior than the EBV-negative one. BTB and CNC homology 2 (BACH2) has been highlighted as a tumor suppressor in hematopoietic malignancies; however, the role of BACH2 in EBV-positive DLBCL is unclear. In the present study, BACH2 expression and its significance were studied in 23 EBV-positive and 43 EBV-negative patient samples. Immunohistochemistry revealed BACH2 downregulation in EBV-positive cases (P < 0.0001), although biallelic deletion of BACH2 was not detected by FISH. Next, we analyzed the contribution of BACH2 negativity to aggressiveness in EBV-positive B-cell lymphomas using FL-18 (EBV-negative) and FL-18-EB cells (FL-18 sister cell line, EBV-positive). In BACH2-transfected FL-18-EB cells, downregulation of phosphorylated transforming growth factor-β-activated kinase 1 (pTAK1) and suppression in p65 nuclear fractions were observed by Western blot analysis contrary to non-transfected FL-18-EB cells. In patient samples, pTAK1 expression and significant nuclear p65, p50, and p52 localization were detected immunohistochemically in BACH2-negative DLBCL (P < 0.0001, P = 0.006, and P = 0.001, respectively), suggesting that BACH2 downregulation contributes to constitutive activation of the nuclear factor-κB pathway through TAK1 phosphorylation in BACH2-negative DLBCL (most EBV-positive cases). Although further molecular and pathological studies are warranted to clarify the detailed mechanisms, downregulation of BACH2 may contribute to constitutive activation of the nuclear factor-κB pathway through TAK1 activation. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Hypoxia-induced Bcl-2 expression in endothelial cells via p38 MAPK pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Cui-Li, E-mail: zhangcuili@hotmail.com; Song, Fei; Zhang, Jing

Angiogenesis and apoptosis are reciprocal processes in endothelial cells. Bcl-2, an anti-apoptotic protein, has been found to have angiogenic activities. The purpose of this study was to determine the role of Bcl-2 in hypoxia-induced angiogenesis in endothelial cells and to investigate the underlying mechanisms. Human aortic endothelial cells (HAECs) were exposed to hypoxia followed by reoxygenation. Myocardial ischemia and reperfusion mouse model was used and Bcl-2 expression was assessed. Bcl-2 expression increased in a time-dependent manner in response to hypoxia from 2 to 72 h. Peak expression occurred at 12 h (3- to 4-fold, p < 0.05). p38 inhibitor (SB203580)more » blocked hypoxia-induced Bcl-2 expression, whereas PKC, ERK1/2 and PI3K inhibitors did not. Knockdown of Bcl-2 resulted in decreased HAECs' proliferation and migration. Over-expression of Bcl-2 increased HAECs' tubule formation, whereas knockdown of Bcl-2 inhibited this process. In this model of myocardial ischemia and reperfusion, Bcl-2 expression was increased and was associated with increased p38 MAPK activation. Our results showed that hypoxia induces Bcl-2 expression in HAECs via p38 MAPK pathway.« less

B-cell lymphoma 2 is associated with advanced tumor grade and clinical stage, and reduced overall survival in young Chinese patients with colorectal carcinoma.

PubMed

Wang, Jiasheng; He, Gan; Yang, Qiang; Bai, Lian; Jian, Bin; Li, Qugang; Li, Zhongfu

2018-06-01

The development of biomarkers that accurately and reliably detect colorectal cancer is a promising approach for colorectal cancer screening. Therefore, the objective of the present study was to evaluate the protein expression of α-methylacyl-CoA racemase (P504S/AMACR), tumor protein p53 (p53), B-cell lymphoma 2 (Bcl-2) and Ki-67/mindbomb E3 ubiquitin protein ligase 1 (MIB-1) in a population of Chinese patients with colorectal carcinoma. Colorectal tumors with matched normal tissue margins were collected from 148 surgical patients, and the demographic and clinical characteristics were collected. Immunohistochemical staining and western blot analysis of P504S/AMACR, p53, Bcl-2 and Ki-67/MIB-1 were conducted. Statistical analyses were used to compare protein expression in the colorectal tumors and matched normal tissue margins and to identify any associations between them and various clinicopathological parameters. Survival analyses were performed using the Kaplan-Meier method. In the present study, immunohistochemistry and western blot analysis revealed significantly higher expression of all four proteins in colorectal tumors compared with matched normal tissue margins (P<0.001). Spearman's rank correlation analysis revealed that Bcl-2 expression was negatively correlated with pathological grade and Tumor-Node-Metastasis (TNM) stage (-0.827 and -0.388, respectively; P<0.05). Bcl-2 expression was revealed to be a significant prognostic indicator of colorectal carcinoma [relative risk (95% CI), 0.703 (0.552-0.895); P<0.05]. The log-rank test revealed a significant association between low Bcl-2 expression and reduced overall survival (P=0.039), as well as a significant association between older age (>55 years) and reduced overall survival (P<0.001) in Chinese patients with colorectal carcinoma. In conclusion, low expression of Bcl-2 is significantly correlated with advanced pathological grade and TNM stage and is a prognostic indicator of reduced overall survival in

Obatoclax, a Pan-BCL-2 Inhibitor, Targets Cyclin D1 for Degradation to Induce Antiproliferation in Human Colorectal Carcinoma Cells.

PubMed

Or, Chi-Hung R; Chang, Yachu; Lin, Wei-Cheng; Lee, Wee-Chyan; Su, Hong-Lin; Cheung, Muk-Wing; Huang, Chang-Po; Ho, Cheesang; Chang, Chia-Che

2016-12-27

Colorectal cancer is the third most common cancer worldwide. Aberrant overexpression of antiapoptotic BCL-2 (B-cell lymphoma 2) family proteins is closely linked to tumorigenesis and poor prognosis in colorectal cancer. Obatoclax is an inhibitor targeting all antiapoptotic BCL-2 proteins. A previous study has described the antiproliferative action of obatoclax in one human colorectal cancer cell line without elucidating the underlying mechanisms. We herein reported that, in a panel of human colorectal cancer cell lines, obatoclax inhibits cell proliferation, suppresses clonogenicity, and induces G₁-phase cell cycle arrest, along with cyclin D1 downregulation. Notably, ectopic cyclin D1 overexpression abrogated clonogenicity suppression but also G₁-phase arrest elicited by obatoclax. Mechanistically, pre-treatment with the proteasome inhibitor MG-132 restored cyclin D1 levels in all obatoclax-treated cell lines. Cycloheximide chase analyses further revealed an evident reduction in the half-life of cyclin D1 protein by obatoclax, confirming that obatoclax downregulates cyclin D1 through induction of cyclin D1 proteasomal degradation. Lastly, threonine 286 phosphorylation of cyclin D1, which is essential for initiating cyclin D1 proteasomal degradation, was induced by obatoclax in one cell line but not others. Collectively, we reveal a novel anticancer mechanism of obatoclax by validating that obatoclax targets cyclin D1 for proteasomal degradation to downregulate cyclin D1 for inducing antiproliferation.