1
|
Krishnan RP, Pandiar D, Ramani P, Jayaraman S. Necroptosis in human cancers with special emphasis on oral squamous cell carcinoma. JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2023; 124:101565. [PMID: 37459966 DOI: 10.1016/j.jormas.2023.101565] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 07/12/2023] [Indexed: 11/06/2023]
Abstract
Necroptosis is a type of caspase independent 'programmed or regulated' necrotic cell death that has a morphological resemblance to necrosis and mechanistic analogy to apoptosis. This type of cell death requires RIPK1, RIPK3, MLKL, death receptors, toll like receptors, interferons, and various other proteins. Necroptosis is implicated in plethora of diseases like rheumatoid arthritis, Alzheimer's disease, Crohn's disease, and head and neck cancers including oral squamous cell carcinoma. Oral carcinomas show dysregulation or mutation of necroptotic proteins, mediate antitumoral immunity, activate immune response and control tumor progression. Necroptosis is known to play a dual role (pro tumorigenic and anti-tumorigenic) in cancer progression and targeting this pathway could be an effective approach in cancer therapy. Necroptosis based chemotherapy has been proposed in malignancies, highlighting the importance of necroptotic pathway to overcome apoptosis resistance and serve as a "fail-safe" pathway to modulate cancer initiation, progression, and metastasis. However, there is dearth of information regarding the use of necroptotic cell death mechanism in the treatment of oral squamous cell carcinoma. In this review, we summarise molecular mechanism of necroptosis, and its protumorigenic and antitumorigenic role in cancers to shed light on the possible therapeutic significance of necroptosis in oral squamous cell carcinoma.
Collapse
Affiliation(s)
| | - Deepak Pandiar
- Department of Oral Pathology and Microbiology, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu.
| | - Pratibha Ramani
- Department of Oral Pathology and Microbiology, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu.
| | - Selvaraj Jayaraman
- Department of Biochemistry, Saveetha Dental College and Hospitals, Chennai, Tamil Nadu.
| |
Collapse
|
2
|
Bhardwaj P, Biswas GP, Mahata N, Ghanta S, Bhunia B. Exploration of binding mechanism of triclosan towards cancer markers using molecular docking and molecular dynamics. CHEMOSPHERE 2022; 293:133550. [PMID: 34999105 DOI: 10.1016/j.chemosphere.2022.133550] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/26/2021] [Accepted: 01/04/2022] [Indexed: 06/14/2023]
Abstract
The molecule 5-chloro-2-(2,4-dichlorophenoxy) phenol is well-known as Triclosan (TCS), which is also a potential endocrine disrupting synthetic chemical. TCS exposure has been connected to the control of the human enoyl-acyl carrier protein-reductase (hER), which has been linked to a range of life threatening diseases. However, other than hER, the new protein targets for TCS that are responsible for a variety of cancers are yet unclear. The goal of this work is to investigate into the protein binding patterns of TCS and proteins from various cancer signaling pathways. Discovery Studio 4.1 was used to perform molecular docking and molecular dynamics (MD) on the protein-triclosan complex. The proteins were first screened using CHARMM-based docking with a CDOCKER energy greater than -21.40 kcal/mol. The CDOCKER energies of Fas-associated death domain (FADD), Receptor-interacting protein 1 (RIP1), F-κB-inducing kinase (NIK), c-Jun N-terminal kinase (JNK), Apoptosis signal-regulating kinase 1 (ASK1), B-cell lymphoma 2 (Bcl-2), Apoptosis-inducing factor (AIF), α-tubulin, and Actin were -20.68 kcal/mol, -26.88 kcal/mol, -23.43 kcal/mol, -22.21 kcal/mol, -20.40 kcal/mol, -21.10 kcal/mol, -20.98 kcal/mol, -24.67 kcal/mol, and -23.09 kcal/mol respectively. MD was performed on the screened proteins by standard dynamics cascade tool using CHARMM Force field. The MD results were accessed using the energy-time graph, root-mean-square deviation (RMSD), and root mean square fluctuations (RMSF). The 100 conformers of α-tubulin, NIK, FADD, and RIP1 were found to have a trend of increasing RMSD, whereas Bcl-2, ASK1, AIF, Actin, and JNK proteins had lower RMSD values. In compared to FADD, AIF, and JNK, the RMSF variations of the Bcl-2, ASK1, α-tubulin, Actin, NIK, and RIP1 residues were shown to be high. Similar patterns were seen in the energy variations, which range from 1000 kcal/mol to 2000 kcal/mol. RIP1 and Bcl-2 showed more variation in the sidechain RMSF in comparison to FADD, ASK1, AIF, Actin, α-tubulin, NIK and JNK. Thus, it can be postulated that AIF and JNK proteins of apoptosis signaling pathway are pivotal in the TCS mediated reactions.
Collapse
Affiliation(s)
- Prashant Bhardwaj
- Department of Computer Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004, India; Department of Computer Science and Engineering, National Institute of Technology, Agartala, 799046, India.
| | - G P Biswas
- Department of Computer Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004, India.
| | - Nibedita Mahata
- Department of Biotechnology, National Institute of Technology Durgapur, Durgapur, 713209, India.
| | - Susanta Ghanta
- Department of Chemistry, National Institute of Technology, Agartala, 799046, India.
| | - Biswanath Bhunia
- Department of Bio Engineering, National Institute of Technology, Agartala, 799046, India.
| |
Collapse
|
3
|
Allain EP, Rouleau M, Le T, Vanura K, Villeneuve L, Caron P, Turcotte V, Lévesque E, Guillemette C. Inactivation of Prostaglandin E 2 as a Mechanism for UGT2B17-Mediated Adverse Effects in Chronic Lymphocytic Leukemia. Front Oncol 2019; 9:606. [PMID: 31334126 PMCID: PMC6621974 DOI: 10.3389/fonc.2019.00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 06/19/2019] [Indexed: 01/22/2023] Open
Abstract
High expression of the metabolic enzyme UDP-glucuronosyltransferase UGT2B17 in chronic lymphocytic leukemia (CLL) cells was associated with poor prognosis in two independent studies. However, the underlying mechanism remains unknown. We hypothesized that UGT2B17 impacts intracellular levels of hormone-like signaling molecules involved in the regulation of gene expression in leukemic cells. We initially confirmed in a third cohort of 291 CLL patients that those with high UGT2B17 displayed poor prognosis (hazard ratio of 2.31, P = 0.015). Consistent with the unfavorable prognostic significance of elevated UGT2B17 expression in CLL patients, high UGT2B17 expression was associated with enhanced proliferation of MEC1 and JVM2 malignant B-cell models. Transcriptomic analyses revealed that high UGT2B17 was linked to a significant alteration of genes related to prostaglandin E2 (PGE2) and to its precursor arachidonic acid, both in cell models and a cohort of 448 CLL patients. In functional assays, PGE2 emerged as a negative regulator of apoptosis in CLL patients and proliferation in cells models, whereas its effect was partially abrogated by high UGT2B17 expression in MEC1 and JVM2 cells. Enzymatic assays and mass-spectrometry analyses established that the UGT2B17 enzyme inactivates PGE2 by its conjugation to glucuronic acid (GlcA) leading to the formation of two glucuronide (G) derivatives. High UGT2B17 expression was further associated with a proficient inactivation of PGE2 to PGE2-G in CLL patient cells and cell models. We conclude that UGT2B17-dependent PGE2 glucuronidation impairs anti-oncogenic PGE2 effects in leukemic cells, thereby partially contributing to disease progression in high UGT2B17 CLL patients.
Collapse
Affiliation(s)
- Eric P Allain
- Pharmacogenomics Laboratory, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec (CHU de Québec) Research Center - Université Laval, Laval University, Québec City, QC, Canada
| | - Michèle Rouleau
- Pharmacogenomics Laboratory, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec (CHU de Québec) Research Center - Université Laval, Laval University, Québec City, QC, Canada
| | - Trang Le
- Division of Hematology and Hemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Katrina Vanura
- Division of Hematology and Hemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Lyne Villeneuve
- Pharmacogenomics Laboratory, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec (CHU de Québec) Research Center - Université Laval, Laval University, Québec City, QC, Canada
| | - Patrick Caron
- Pharmacogenomics Laboratory, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec (CHU de Québec) Research Center - Université Laval, Laval University, Québec City, QC, Canada
| | - Véronique Turcotte
- Pharmacogenomics Laboratory, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec (CHU de Québec) Research Center - Université Laval, Laval University, Québec City, QC, Canada
| | - Eric Lévesque
- Division of Hemato-Oncology, Faculty of Medicine, CHU de Québec Research Centre - Université Laval, Laval University, Québec City, QC, Canada
| | - Chantal Guillemette
- Pharmacogenomics Laboratory, Faculty of Pharmacy, Centre Hospitalier Universitaire de Québec (CHU de Québec) Research Center - Université Laval, Laval University, Québec City, QC, Canada.,Canada Research Chair in Pharmacogenomics, Québec City, QC, Canada
| |
Collapse
|
4
|
Xiang X, Wang YP, Cao H, Zhang X. Knowledge database assisted gene marker selection for chronic lymphocytic leukemia. J Int Med Res 2018; 46:3358-3364. [PMID: 29996709 PMCID: PMC6134680 DOI: 10.1177/0300060518783072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective To investigate whether previously curated chronic lymphocytic leukemia (CLL) risk genes could be leveraged in gene marker selection for the diagnosis and prediction of CLL. Methods A CLL genetic database (CLL_042017) was developed through a comprehensive CLL-gene relation data analysis, in which 753 CLL target genes were curated. Expression values for these genes were used for case-control classification of four CLL datasets, with a sparse representation-based variable selection (SRVS) approach employed for feature (gene) selection. Results were compared with outcomes obtained by using analysis of variance (ANOVA)-based gene selection approaches. Results For each of the four datasets, SRVS selected a subset of genes from the 753 CLL target genes, resulting in significantly higher classification accuracy, compared with randomly selected genes (100%, 100%, 93.94%, 89.39%). The SRVS method outperformed ANOVA in terms of classification accuracy. Conclusion Gene markers selected from the 753 CLL genes could enable significantly greater accuracy in the prediction of CLL. SRVS provides an effective method for gene marker selection.
Collapse
Affiliation(s)
- Xixi Xiang
- 1 Center of Hematology, The Second Affiliated Hospital of Army Military Medical University, No 83 Xinqiao Street, Shapingba District, Chongqing, 40037, China
| | - Yu-Ping Wang
- 2 Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Hongbao Cao
- 3 Department of Genomics Research, R&D Solutions, Elsevier Inc., Rockville, MD, USA.,4 Unit on Statistical Genomics, NIMH/NIH, Bethesda, MD, USA
| | - Xi Zhang
- 1 Center of Hematology, The Second Affiliated Hospital of Army Military Medical University, No 83 Xinqiao Street, Shapingba District, Chongqing, 40037, China
| |
Collapse
|
5
|
Liu FT, Jia L, Wang P, Wang H, Farren TW, Agrawal SG. STAT3 and NF-κB cooperatively control in vitro spontaneous apoptosis and poor chemo-responsiveness in patients with chronic lymphocytic leukemia. Oncotarget 2017; 7:32031-45. [PMID: 27074565 PMCID: PMC5077994 DOI: 10.18632/oncotarget.8672] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/29/2016] [Indexed: 12/26/2022] Open
Abstract
Chronic lymphocytic leukemia (CLL) is an adult disease characterized by in vivo accumulation of mature CD5/CD19/CD23 triple positive B cells and is currently incurable. CLL cells undergo spontaneous apoptosis in response to in vitro cell culture condition but the underlying mechanism is unclear. We hypothesize that the sensitivity of CLL cells to spontaneous apoptosis may be associated with the constitutive activities of transcription factors STAT3 and/or NF-κB. We now show that the sensitivity of fresh CLL cells to spontaneous apoptosis is highly variable among different patients during 48 hours’ cell culture and inversely correlated with in vivo constitutively activated STAT3 and NF-κB (p < 0.001). Both activated STAT3 and NF-κB maintain the levels of anti-apoptotic protein Mcl-1/Bcl-xL and autocrine IL-6 production. CLL cells with higher susceptibility to in vitro spontaneous apoptosis show the greatest chemosensitivity (p < 0.001), which is reflected clinically as achieving a complete response (CR) (p < 0.001), longer lymphocyte doubling times (p < 0.01), time to first treatment (p < 0.01), and progression free survival (p < 0.05). Our data suggest that the sensitivity of CLL cells to in vitro spontaneous apoptosis is co-regulated by constitutively activated STAT3 and NF-κB and reflects the in vivo chemo-responsiveness and clinical outcomes.
Collapse
Affiliation(s)
- Feng-Ting Liu
- Department of Radiobiology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Centre for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Li Jia
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| | - Ping Wang
- Department of Radiobiology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Centre for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Huaqing Wang
- Department of Medical Oncology, Tianjin Union Medicine Center, Tianjin, China
| | - Timothy W Farren
- Pathology Group, Blizard Institute, Queen Mary University of London, London, UK
| | - Samir G Agrawal
- Centre for Haemato-Oncology, Barts Cancer Institute, Queen Mary University of London, London, UK
| |
Collapse
|
6
|
Baraka A, Shorbagy SE, Elfarargy OM, Haggag R, Abdelaziz LA, Elsayed SF, Elbana KA. Prognostic Significance of Apoptosis Regulators in B-Cell Chronic Lymphocytic Leukemia. ACTA ACUST UNITED AC 2017. [DOI: 10.4236/jct.2017.84032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
7
|
Batool M, Anwar MA, Choi S. Toll-like receptors targeting technology for the treatment of lymphoma. Expert Opin Drug Discov 2016; 11:1047-1059. [PMID: 27602749 DOI: 10.1080/17460441.2016.1233964] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION The crucial role of Toll-like Receptors (TLRs) in innate and adaptive immune systems is well discussed in the literature. In cancer, TLRs act as a double-edged sword that can promote or suppress tumor growth. Areas covered: In this article, the authors uncover the potential role of TLRs in lymphomas, which are cancers related to the lymphatic system and blood cells. TLRs are de facto inflammation-inducing receptors that can either worsen disease or ameliorate lymphoma treatment. From this perspective, the usage of TLRs to modulate the immune system toward lymphoma regression is desirable. Various strategies have been used so far, and novel ways are being sought out to cure lymphoma. Expert opinion: TLR ligands have successfully been used to improve patient health; however, these receptors must be finely tuned to further optimize therapy. For a better outcome, novel specific ligands, improved pharmacodynamics, and unique targets should be discerned. Ligands with conjugated molecules, nanoparticles, and targeted drug delivery can highly optimize the therapy for lymphoma with various etiologies.
Collapse
Affiliation(s)
- Maria Batool
- a Department of Molecular Science and Technology , Ajou University , Suwon , Korea
| | - Muhammad Ayaz Anwar
- a Department of Molecular Science and Technology , Ajou University , Suwon , Korea
| | - Sangdun Choi
- a Department of Molecular Science and Technology , Ajou University , Suwon , Korea
| |
Collapse
|
8
|
Admoni-Elisha L, Nakdimon I, Shteinfer A, Prezma T, Arif T, Arbel N, Melkov A, Zelichov O, Levi I, Shoshan-Barmatz V. Novel Biomarker Proteins in Chronic Lymphocytic Leukemia: Impact on Diagnosis, Prognosis and Treatment. PLoS One 2016; 11:e0148500. [PMID: 27078856 PMCID: PMC4831809 DOI: 10.1371/journal.pone.0148500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 01/19/2016] [Indexed: 12/31/2022] Open
Abstract
In many cancers, cells undergo re-programming of metabolism, cell survival and anti-apoptotic defense strategies, with the proteins mediating this reprogramming representing potential biomarkers. Here, we searched for novel biomarker proteins in chronic lymphocytic leukemia (CLL) that can impact diagnosis, treatment and prognosis by comparing the protein expression profiles of peripheral blood mononuclear cells from CLL patients and healthy donors using specific antibodies, mass spectrometry and binary logistic regression analyses and other bioinformatics tools. Mass spectrometry (LC-HR-MS/MS) analysis identified 1,360 proteins whose expression levels were modified in CLL-derived lymphocytes. Some of these proteins were previously connected to different cancer types, including CLL, while four other highly expressed proteins were not previously reported to be associated with cancer, and here, for the first time, DDX46 and AK3 are linked to CLL. Down-regulation expression of two of these proteins resulted in cell growth inhibition. High DDX46 expression levels were associated with shorter survival of CLL patients and thus can serve as a prognosis marker. The proteins with modified expression include proteins involved in RNA splicing and translation and particularly mitochondrial proteins involved in apoptosis and metabolism. Thus, we focused on several metabolism- and apoptosis-modulating proteins, particularly on the voltage-dependent anion channel 1 (VDAC1), regulating both metabolism and apoptosis. Expression levels of Bcl-2, VDAC1, MAVS, AIF and SMAC/Diablo were markedly increased in CLL-derived lymphocytes. VDAC1 levels were highly correlated with the amount of CLL-cancerous CD19+/CD5+ cells and with the levels of all other apoptosis-modulating proteins tested. Binary logistic regression analysis demonstrated the ability to predict probability of disease with over 90% accuracy. Finally, based on the changes in the levels of several proteins in CLL patients, as revealed from LC-HR-MS/MS, we could distinguish between patients in a stable disease state and those who would be later transferred to anti-cancer treatments. The over-expressed proteins can thus serve as potential biomarkers for early diagnosis, prognosis, new targets for CLL therapy, and treatment guidance of CLL, forming the basis for personalized therapy.
Collapse
MESH Headings
- Aged
- Biomarkers, Tumor/blood
- Biomarkers, Tumor/genetics
- Blotting, Western
- Chromatography, Liquid
- Female
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis
- Leukocytes, Mononuclear/metabolism
- Male
- Prognosis
- Proteome/analysis
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Reverse Transcriptase Polymerase Chain Reaction
- Tandem Mass Spectrometry/methods
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- Lee Admoni-Elisha
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Itay Nakdimon
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Anna Shteinfer
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Tal Prezma
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Tasleem Arif
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Nir Arbel
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Anna Melkov
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Ori Zelichov
- Department of Hematology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Itai Levi
- Department of Hematology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Varda Shoshan-Barmatz
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
- * E-mail:
| |
Collapse
|
9
|
Prezma T, Shteinfer A, Admoni L, Raviv Z, Sela I, Levi I, Shoshan-Barmatz V. VDAC1-based peptides: novel pro-apoptotic agents and potential therapeutics for B-cell chronic lymphocytic leukemia. Cell Death Dis 2013; 4:e809. [PMID: 24052077 PMCID: PMC3789174 DOI: 10.1038/cddis.2013.316] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 07/15/2013] [Accepted: 07/19/2013] [Indexed: 12/20/2022]
Abstract
The voltage-dependent anion channel 1 (VDAC1), localized in the outer mitochondrial membrane, mediates metabolic cross-talk between the mitochondrion and the cytoplasm and thus serves a fundamental role in cell energy metabolism. VDAC1 also plays a key role in mitochondria-mediated apoptosis, interacting with anti-apoptotic proteins. Resistance of cancer cells to apoptosis involves quenching the mitochondrial apoptotic pathway by over-expression of anti-apoptotic/pro-survival hexokinase (HK) and Bcl-2 family proteins, proteins that mediate their anti-apoptotic activities via interaction with VDAC1. Using specifically designed VDAC1-based cell-penetrating peptides, we targeted these anti-apoptotic proteins to prevent their pro-survival/anti-apoptotic activities. Anti-apoptotic proteins are expressed at high levels in B-cell chronic lymphocytic leukemia (CLL), an incurable disease requiring innovative new approaches to improve therapeutic outcome. CLL is characterized by a clonal accumulation of mature neoplastic B cells that are resistant to apoptosis. Specifically, we demonstrate that the VDAC1-based peptides (Antp-LP4 and N-Terminal-Antp) selectively kill peripheral blood mononuclear cells (PBMCs) obtained from CLL patients, yet spare those obtained from healthy donors. The cell death induction competence of the peptides was well correlated with the amount of double positive CD19/CD5 cancerous CLL PBMCs, further illustrating their selectivity toward cancer cells. Moreover, these VDAC1-based peptides induced apoptosis by activating the mitochondria-mediated pathway, reflected in membrane blebbing, condensation of nuclei, DNA fragmentation, release of mitochondrial cytochrome c, loss of mitochondrial membrane potential, decreased cellular ATP levels and detachment of HK, all leading to apoptotic cell death. Thus, the mode of action of the peptides involves decreasing energy production and inducing apoptosis. Over 27 versions of cell-penetrating VDAC1-based peptides were designed and screened to identify the most stable, short and apoptosis-inducing peptides toward CLL-derived lymphocytes. In this manner, three optimized peptides suitable for in vivo studies were identified. This study thus reveals the potential of VDAC1-based peptides as an innovative and effective anti-CLL therapy.
Collapse
Affiliation(s)
- T Prezma
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, BeerSheva, Israel
| | | | | | | | | | | | | |
Collapse
|
10
|
Patel V, Chen LS, Wierda WG, Balakrishnan K, Gandhi V. Impact of bone marrow stromal cells on Bcl-2 family members in chronic lymphocytic leukemia. Leuk Lymphoma 2013; 55:899-910. [PMID: 23837491 DOI: 10.3109/10428194.2013.819573] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia in the Western world. High levels of Bcl-2 family anti-apoptotic proteins are responsible for apoptosis resistance. Besides anti-apoptotic proteins, the microenvironment provides substantial survival signals to CLL leukemic cells. However, in-depth knowledge on the role of individual Bcl-2 family members in the context of the microenvironment is still limited. We performed a comprehensive analysis of transcripts and proteins of 18 Bcl-2 family members using an "apoptosis array microfluidic card" in primary cells before and after stromal co-cultures. Our data showed that five of six anti-apoptotic members (excluding Bcl-b), two of three pro-apoptotic members (excluding Bok) and six of nine BH3-only members were present at detectable mRNA levels in CLL cells. Importantly, stromal-mediated extended survival of CLL cells was strongly associated with elevated global transcription. Upon co-culturing with stromal cells, there was an early response of an increase in anti- (2/5) and pro-apoptotic protein (3/8) transcripts on day 1, while an increase in anti-apoptotic proteins was observed on day 3, with no significant change in pro-apoptotic proteins. Our study revealed a differential pattern of expression of both transcripts and proteins following stromal co-cultures, proposing a significance of Bcl-2 family members in the stromal microenvironment.
Collapse
|
11
|
Sachanas S, Levidou G, Angelopoulou MK, Moschogiannis M, Yiakoumis X, Kalpadakis C, Vassilakopoulos TP, Kontopidou F, Tsirkinidis P, Dimitrakopoulou A, Kokoris S, Dimitriadou E, Kyrtsonis MC, Panayiotidis P, Papadaki H, Patsouris E, Korkolopoulou P, Pangalis GA. Apoptotic and proliferative characteristics of proliferation centers in lymph node sections of patients with chronic lymphocytic leukemia. Leuk Lymphoma 2013; 55:571-82. [PMID: 23697878 DOI: 10.3109/10428194.2013.806802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have analyzed the immunohistochemical expression of a wide range of molecules along with the proliferation rate separately in the proliferation centers (PCs) and in the rest of the tumor area, in lymph node or spleen sections of patients with chronic lymphocytic leukemia (CLL). Fas, FasL and c-FLIP were observed both within and outside the PCs in all cases. However, only the difference in FasL expression between the PCs and the non-PC areas attained statistical significance. Median survivin expression in the PCs was higher compared to the non-PC areas. Cleaved caspase 3 was expressed at very low levels both within and outside PCs, while BCL-2 protein was expressed at high levels in all cases in both tumor compartments. Multivariate analysis demonstrated that concurrent overexpression of Fas/FasL/c-FLIP in the PCs was correlated with worse outcome for progression-free survival as well as for overall survival.
Collapse
|
12
|
Zhang W, Feng L, Pelicano H, Huang P. [Resistance of chronic lymphocytic leukemia cells in apoptosis: key role of stromal cells in maintaining the redox potential of CLL cells]. Med Sci (Paris) 2013; 29:36-8. [PMID: 23351693 DOI: 10.1051/medsci/2013291012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
MESH Headings
- Animals
- Apoptosis
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukemia, Lymphocytic, Chronic, B-Cell/physiopathology
- Oxidation-Reduction
- Receptors, CXCR3
- Stromal Cells/physiology
Collapse
|
13
|
Scupoli MT, Pizzolo G. Signaling pathways activated by the B-cell receptor in chronic lymphocytic leukemia. Expert Rev Hematol 2012; 5:341-8. [PMID: 22780213 DOI: 10.1586/ehm.12.21] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Over the past decade, several features of the B-cell receptor (BCR) complex have emerged as major markers for prognostic classification of B-cell chronic lymphocytic leukemia (B-CLL). In particular, the absence of somatic mutations within the immunoglobulin variable heavy chain genes (IGHV), the presence of ZAP-70 and a higher ability of the BCR to translate signals within the cell have been associated with an aggressive clinical course. Indeed, the stratification of patients with B-CLL based on BCR features suggests that heterogeneity of B-CLL clinical courses may reflect BCR signaling differences that have arisen during the evolution of leukemia. Therefore, characterizing BCR signaling profiles may help to identify signaling markers useful for patient stratification, disease monitoring and therapeutic targeting in B-CLL.
Collapse
Affiliation(s)
- Maria Teresa Scupoli
- Department of Medicine, Section of Hematology, University of Verona, Verona, Italy.
| | | |
Collapse
|
14
|
Li S, Wan M, Cao X, Ren Y. Expression of AIF and HtrA2/Omi in small lymphocytic lymphoma and diffuse large B-cell lymphoma. Arch Pathol Lab Med 2011; 135:903-8. [PMID: 21732781 DOI: 10.5858/2010-0003-oar1.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT The pathogenesis of non-Hodgkin lymphoma may involve deregulation of apoptosis. In response to apoptotic stimuli, several proapoptotic proteins are released into the cytoplasm from the mitochondria, including second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein binding protein with low p I (Smac/DIABLO), apoptosis-inducing factor (AIF), and high temperature requirement protein A2 (HtrA2/Omi). Apoptosis-inducing factor promotes apoptosis through a caspase-independent pathway, while Smac/DIABLO and HtrA2/Omi do so through both caspase-dependent and caspase-independent pathways. Smac/DIABLO was reported to be strongly positive in diffuse large B-cell lymphoma (DLBCL) and virtually absent in small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL). Little is known about the expression of AIF and HtrA2/Omi in lymphomas. OBJECTIVE To evaluate the expression of AIF and HtrA2/Omi in SLL and DLBCL. DESIGN Twenty-three DLBCLs, 20 SLLs/CLLs, and 10 benign lymph nodes were evaluated for AIF and HtrA2/Omi expression by immunohistochemical staining. RESULTS Apoptosis-inducing factor was strongly and diffusely expressed in 19 of 23 (83%) cases of DLBCL with comparable expression pattern between germinal center-like and non-germinal center-like subgroups. Apoptosis-inducing factor was weakly positive in 15 of 20 (75%) cases of SLL/CLL with increased intensity in pseudofollicles. In contrast, HtrA2/Omi was weakly expressed in SLL/CLL (17 of 20; 85%) and DLBCL (18 of 23; 78%). CONCLUSIONS The different expression level and pattern of AIF and HtrA2/Omi in SLL/CLL and DLBCL may suggest different apoptotic mechanisms involved in the pathogenesis and prognosis of these diseases. HtrA2/Omi does not appear to be a major player in the regulation of apoptosis of DLBCL and SLL/CLL.
Collapse
Affiliation(s)
- Shaoying Li
- Department of Pathology, University of Alabama at Birmingham Health System, Birmingham, USA.
| | | | | | | |
Collapse
|
15
|
Straten PT, Andersen MH. The anti-apoptotic members of the Bcl-2 family are attractive tumor-associated antigens. Oncotarget 2011; 1:239-45. [PMID: 21304176 DOI: 10.18632/oncotarget.100804] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Anti-apoptotic members of the Bcl-2 family (Bcl-2, Bcl-X(L) and Mcl-2) are pivotal regulators of apoptotic cell death. They are all highly overexpressed in cancers of different origin in which they enhance the survival of the cancer cells. Consequently, they represent prime candidates for anti-cancer therapy and specific antisense oligonucleotides or small molecule inhibitors have shown broad anti-cancer activities in pre-clinical models and are currently tested in clinical trials. In addition, immune-mediated tumor destruction is emerging as an interesting modality to treat cancer patients. Notably, spontaneous cellular immune responses against the Bcl-2 family proteins have been identified as frequent features in cancer patients underscoring that these proteins are natural targets for the immune system. Thus, Bcl-2 family may serve as an important and widely applicable target for anti-cancer immunotherapeutic strategies, alone or in the combination with conventional therapy. Here, we summarize the current knowledge of Bcl-2 family proteins as T-cell antigens, which has set the stage for the first explorative trial using these antigens in therapeutic vaccinations against cancer, and discuss future opportunities.
Collapse
Affiliation(s)
- Per thor Straten
- Center for Cancer Immune Therapy, Department of Hematology, Herlev University Hospital, Denmark
| | | |
Collapse
|
16
|
Dürig J, Dührsen U, Klein-Hitpass L, Worm J, Hansen JBR, Ørum H, Wissenbach M. The novel antisense Bcl-2 inhibitor SPC2996 causes rapid leukemic cell clearance and immune activation in chronic lymphocytic leukemia. Leukemia 2011; 25:638-47. [PMID: 21358717 DOI: 10.1038/leu.2010.322] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
SPC2996 is a novel locked nucleic acid phosphorothioate antisense molecule targeting the mRNA of the Bcl-2 oncoprotein. We investigated the mechanism of action of SPC2996 and the basis for its clinically observed immunostimulatory effects in chronic lymphocytic leukemia (CLL). Patients with relapsed CLL were treated with a maximum of six doses of SPC2996 (0.2-6 mg/kg) in a multicenter phase I trial. Microarray-based transcriptional profiling of circulating CLL cells was carried out before and after the first infusion of SPC2996 in 18 patients. Statistically significant transcriptomic changes were observed at doses 4 mg/kg and occurred as early as 24 h after the first infusion of the oligonucleotide. SPC2996 induced the upregulation of 466 genes including a large number of immune response and apoptotic regulator molecules, which were enriched for Toll-like receptor response genes. Serum measurements confirmed the release of pro-inflammatory cytokines including chemokine (C-C motif) ligand 3 (macrophage inflammatory protein 1α) and tumor necrosis factor-α, thereby validating the in vivo transcriptomic data at the protein level. SPC2996 caused a 50% reduction of circulating lymphocytes in five of 18 (28%) patients, which was found to be independent of its immunostimulatory and anti-Bcl-2 effects.
Collapse
Affiliation(s)
- J Dürig
- Department of Hematology, University Hospital, University of Duisburg-Essen, Essen, Germany.
| | | | | | | | | | | | | |
Collapse
|
17
|
Thor Straten P, Andersen MH. The anti-apoptotic members of the Bcl-2 family are attractive tumor-associated antigens. Oncotarget 2010; 1:239-245. [PMID: 21304176 PMCID: PMC3248102 DOI: 10.18632/oncotarget.134] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 08/09/2010] [Indexed: 11/25/2022] Open
Abstract
Anti-apoptotic members of the Bcl-2 family (Bcl-2, Bcl-X(L) and Mcl-2) are pivotal regulators of apoptotic cell death. They are all highly overexpressed in cancers of different origin in which they enhance the survival of the cancer cells. Consequently, they represent prime candidates for anti-cancer therapy and specific antisense oligonucleotides or small molecule inhibitors have shown broad anti-cancer activities in pre-clinical models and are currently tested in clinical trials. In addition, immune-mediated tumor destruction is emerging as an interesting modality to treat cancer patients. Notably, spontaneous cellular immune responses against the Bcl-2 family proteins have been identified as frequent features in cancer patients underscoring that these proteins are natural targets for the immune system. Thus, Bcl-2 family may serve as an important and widely applicable target for anti-cancer immunotherapeutic strategies, alone or in the combination with conventional therapy. Here, we summarize the current knowledge of Bcl-2 family proteins as T-cell antigens, which has set the stage for the first explorative trial using these antigens in therapeutic vaccinations against cancer, and discuss future opportunities.
Collapse
|
18
|
Impaired expression of p66Shc, a novel regulator of B-cell survival, in chronic lymphocytic leukemia. Blood 2010; 115:3726-36. [PMID: 20061561 DOI: 10.1182/blood-2009-08-239244] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Intrinsic apoptosis defects underlie to a large extent the extended survival of malignant B cells in chronic lymphocytic leukemia (CLL). Here, we show that the Shc family adapter p66Shc uncouples the B-cell receptor (BCR) from the Erk- and Akt-dependent survival pathways, thereby enhancing B-cell apoptosis. p66Shc expression was found to be profoundly impaired in CLL B cells compared with normal peripheral B cells. Moreover, significant differences in p66Shc expression were observed in patients with favorable or unfavorable prognosis, based on the mutational status of IGHV genes, with the lowest expression in the unfavorable prognosis group. Analysis of the expression of genes implicated in apoptosis defects of CLL showed an alteration in the balance of proapoptotic and antiapoptotic members of the Bcl-2 family in patients with CLL. Reconstitution experiments in CLL B cells, together with data obtained on B cells from p66Shc(-/-) mice, showed that p66Shc expression correlates with a bias in the Bcl-2 family toward proapoptotic members. The data identify p66Shc as a novel regulator of B-cell apoptosis which attenuates BCR-dependent survival signals and modulates Bcl-2 family expression. They moreover provide evidence that the p66Shc expression defect in CLL B cells may be causal to the imbalance toward the antiapoptotic Bcl-2 family members in these cells.
Collapse
|
19
|
Pizzirani D, Roberti M, Grimaudo S, Di Cristina A, Pipitone RM, Tolomeo M, Recanatini M. Identification of biphenyl-based hybrid molecules able to decrease the intracellular level of Bcl-2 protein in Bcl-2 overexpressing leukemia cells. J Med Chem 2009; 52:6936-40. [PMID: 19764793 DOI: 10.1021/jm900907s] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the aim of enhancing the structural complexity and diversity of an existing collection of bi- and terphenyl compounds, we synthesized hybrid molecules comprising of spirocyclic ketones (a complexity-bearing core) and bi/terphenyls (privileged fragments). Compounds 1, 3, 4, and 6 showed well-defined activity on apoptosis and differentiation, making them potential leads for development as new anticancer agents and chemical probes to study signaling networks in neoplastic cells.
Collapse
Affiliation(s)
- Daniela Pizzirani
- Department of Chemistry and Chemical Biology, Harvard University and the Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02138, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Shanafelt TD, Call TG, Zent CS, LaPlant B, Bowen DA, Roos M, Secreto CR, Ghosh AK, Kabat BF, Lee MJ, Yang CS, Jelinek DF, Erlichman C, Kay NE. Phase I trial of daily oral Polyphenon E in patients with asymptomatic Rai stage 0 to II chronic lymphocytic leukemia. J Clin Oncol 2009; 27:3808-14. [PMID: 19470922 PMCID: PMC2727287 DOI: 10.1200/jco.2008.21.1284] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Accepted: 02/09/2009] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To define the optimal dose of Polyphenon E for chronic daily administration and tolerability in patients with chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS Previously untreated patients with asymptomatic Rai stage 0 to II CLL were eligible for participation. Polyphenon E with a standardized dose of epigallocatechin-3-gallate (EGCG) was administered using the standard phase I design with three to six patients per dose level (range, 400 to 2,000 mg by mouth twice a day). Trough plasma EGCG levels were measured 1 month after initiation of therapy. Response was classified using the National Cancer Institute (NCI) Working Group (WG) Criteria. RESULTS Thirty-three eligible patients were accrued to dose levels 1 to 8. The maximum-tolerated dose was not reached. The most common adverse effects included transaminitis (33%, all grade 1), abdominal pain (30% grade 1, 0% grade 2, and 3% grade 3), and nausea (39% grade 1 and 9% grade 2). One patient experienced an NCI WG partial remission. Other signs of clinical activity were also observed, with 11 patients (33%) having a sustained > or = 20% reduction in absolute lymphocyte count (ALC) and 11 (92%) of 12 patients with palpable adenopathy experiencing at least a 50% reduction in the sum of the products of all nodal areas during treatment. Trough plasma EGCG levels after 1 month of treatment ranged from 2.9 to 3,974 ng/mL (median, 40.4 ng/mL). CONCLUSION Daily oral EGCG in the Polyphenon E preparation was well tolerated by CLL patients in this phase I trial. Declines in ALC and/or lymphadenopathy were observed in the majority of patients. A phase II trial to evaluate efficacy using 2,000 mg twice a day began in November 2007.
Collapse
|
21
|
Bergom C, Gao C, Newman PJ. Mechanisms of PECAM-1-mediated cytoprotection and implications for cancer cell survival. Leuk Lymphoma 2009; 46:1409-21. [PMID: 16194886 DOI: 10.1080/10428190500126091] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Defects in apoptotic pathways can promote cancer development and cause cancers to become resistant to chemotherapy. The cell adhesion and signaling molecule PECAM-1 has been shown to potently suppress apoptosis in a variety of cellular systems. PECAM-1 expression has been reported on a variety of human malignancies-especially hematopoietic and vascular cell cancers-but the significance of this expression has not been fully explored. The ability of PECAM-1 to inhibit apoptosis makes it an attractive candidate as a molecule that may promote cancer development and/or confer resistance to chemotherapeutic treatment. The exact mechanisms by which PECAM-1 mediates its cytoprotection have not been fully defined, but its anti-apoptotic effects have been shown to require both homophilic binding and intracellular signaling via its immunoreceptor tyrosine-based inhibitory motif (ITIM) domains. In this review, we will discuss the data regarding PECAM-1's anti-apoptotic effects and ways in which this cytoprotection may be clinically relevant to the development and/or treatment of hematologic malignancies that express this vascular cell-specific surface molecule.
Collapse
Affiliation(s)
- Carmen Bergom
- Blood Research Institute, The Blood Center of Southeastern Wisconsin, Milwaukee, Milwaukee, WI, USA.
| | | | | |
Collapse
|
22
|
Fulda S. Therapeutic opportunities for counteracting apoptosis resistance in childhood leukaemia. Br J Haematol 2009; 145:441-54. [DOI: 10.1111/j.1365-2141.2009.07603.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
23
|
Hewamana S, Lin TT, Rowntree C, Karunanithi K, Pratt G, Hills R, Fegan C, Brennan P, Pepper C. Rel a is an independent biomarker of clinical outcome in chronic lymphocytic leukemia. J Clin Oncol 2009; 27:763-9. [PMID: 19124804 DOI: 10.1200/jco.2008.19.1114] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE We recently demonstrated the biologic importance of the nuclear factor kappa B (NF-kappaB) subunit Rel A in chronic lymphocytic leukemia (CLL) and hypothesized that Rel A DNA binding would have prognostic significance in this disease. PATIENTS AND METHODS Rel A DNA binding was quantified in nuclear extracts derived from 131 unselected CLL patient samples using a quantitative DNA-binding enzyme-linked immunosorbent assay-based method. We then investigated the ability of Rel A to predict for the requirement for treatment and survival and compared our findings with other established prognostic markers. RESULTS Rel A DNA binding was strongly associated with advanced Binet stage (P < .0001) but did not correlate with immunoglobulin V(H) (IgV(H)) mutation status (P = .25), CD38 expression (P = .87), or zeta-chain-associated protein kinase 70 (ZAP-70) expression (P = .55). It was predictive of time to first treatment (P = .02) and time to subsequent treatment (P = .0001). In addition, Rel A was the most predictive marker of survival both from date of diagnosis (hazard ratio [HR], 9.1; P = .01) and date of entry into the study (HR, 3.9; P = .05) and retained prognostic significance in multivariate analysis for both time to first treatment and overall survival in the presence of Binet stage, IgV(H) mutation status, CD38, and ZAP-70. CONCLUSION Rel A is an independent prognostic marker of survival in CLL and seems to have the unique capacity to predict the duration of response to therapy. Prospective assessment of Rel A as a marker of clinical outcome and as a therapeutic target are now warranted.
Collapse
Affiliation(s)
- Saman Hewamana
- Department of Haematology, School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
AT-101 induces apoptosis in CLL B cells and overcomes stromal cell-mediated Mcl-1 induction and drug resistance. Blood 2008; 113:149-53. [PMID: 18836097 DOI: 10.1182/blood-2008-02-138560] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Resistance to apoptosis in CLL B cells is associated with overexpression of Bcl-2 family antiapoptotic proteins. Their expression is endogenous, but is also induced by signals from the microenvironment resulting in intrinsic and extrinsic drug resistance. Because AT-101 binds to the BH3 motif of all Bcl-2-family antiapoptotic proteins, we hypothesized that this molecule could overcome resistance. AT-101 treatment (20 microM for 24 hours) resulted in a median 72% apoptosis in CLL cells (patients; n = 32, P < .001). Stromal cells protected CLL B cells from spontaneous and fludarabine-induced apoptosis (P = .003) by increasing the Mcl-1 protein levels. However, AT-101 induced similar extent of down-regulation of Mcl-1 and apoptosis in CLL lymphocytes cultured in suspension or on stroma (P = .999). Stromal cells expressed undetectable levels of antiapoptotic but high levels of activated ERK and AKT proteins and had low or no apoptosis with AT-101. Collectively, these data demonstrate that AT-101 induces apoptosis in CLL B cells and overcomes microenvironment-mediated resistance while sparing normal stromal cells.
Collapse
|
25
|
Zhai D, Jin C, Shiau CW, Kitada S, Satterthwait AC, Reed JC. Gambogic acid is an antagonist of antiapoptotic Bcl-2 family proteins. Mol Cancer Ther 2008; 7:1639-46. [PMID: 18566235 DOI: 10.1158/1535-7163.mct-07-2373] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The natural product gambogic acid (GA) has been reported to have cytotoxic activity against tumor cells in culture and was identified as an active compound in a cell-based high-throughput screening assay for activators of caspases, proteases involved in apoptosis. Using the antiapoptotic Bcl-2 family protein, Bfl-1, as a target for screening of a library of natural products, we identified GA as a competitive inhibitor that displaced BH3 peptides from Bfl-1 in a fluorescence polarization assay. Analysis of competition for BH3 peptide binding revealed that GA inhibits all six human Bcl-2 family proteins to various extents, with Mcl-1 and Bcl-B the most potently inhibited [concentrations required for 50% inhibition (IC(50)), < 1 micromol/L]. Competition for BH3 peptide binding was also confirmed using a time-resolved fluorescence resonance energy transfer assay. GA functionally inhibited the antiapoptotic Bcl-2 family proteins as shown by experiments using isolated mitochondria in which recombinant purified Bcl-2 family proteins suppress SMAC release in vitro, showing that GA neutralizes their suppressive effects on mitochondria in a concentration-dependent manner. GA killed tumor cell lines via an apoptotic mechanism, whereas analogues of GA with greatly reduced potency at BH3 peptide displacement showed little or no cytotoxic activity. However, GA retained cytotoxic activity against bax-/-bak-/- cells in which antiapoptotic Bcl-2 family proteins lack a cytoprotective phenotype, implying that GA also has additional targets that contribute to its cytotoxic mechanism. Altogether, the findings suggest that suppression of antiapoptotic Bcl-2 family proteins may be among the cytotoxic mechanisms by which GA kills tumor cells.
Collapse
Affiliation(s)
- Dayong Zhai
- Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | | | |
Collapse
|
26
|
Apoptosis in leukemia: From molecular pathways to targeted therapies. Best Pract Res Clin Haematol 2008; 21:5-11. [DOI: 10.1016/j.beha.2007.11.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
27
|
Mediation of apoptosis by and antitumor activity of lumiliximab in chronic lymphocytic leukemia cells and CD23+ lymphoma cell lines. Blood 2008; 111:1594-602. [DOI: 10.1182/blood-2007-03-082024] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractLumiliximab is a chimeric macaque-human monoclonal antibody to CD23, a protein expressed on virtually all chronic lymphocytic leukemia (CLL) cells. We examined the ability of lumiliximab to mediate apoptosis, antibody-dependent cellular cytotoxicity, and complement-dependent cytotoxicity against primary CLL cells and CD23-expressing B-cell lines. Our data suggest that lumiliximab kills CLL cells and CD23-expressing B cells predominantly by apoptosis, which occurs through the intrinsic pathway. Lumiliximab-induced apoptosis was accompanied by the down-regulation of antiapoptotic proteins Bcl-2, Bcl-XL, and XIAP, activation of Bax, and release of cytochrome c from the mitochondria. We also found that the addition of lumiliximab to rituximab or fludarabine results in synergistic cytotoxicity of primary CLL cells and CD23-expressing B-cell lines. We investigated the in vivo activity of lumiliximab in a human disseminated CD23+ B-cell lymphoma SCID mouse model and found greater antitumor activity with it than with control antibody. We also found that paralysis-free survival was greater with lumiliximab plus rituximab or fludarabine than with any of those agents alone. These results suggest that lumiliximab may be an effective treatment alone or in combination with rituximab or chemotherapy agents in CLL or other CD23-overexpressing B-cell malignancies.
Collapse
|
28
|
Del Gaizo Moore V, Letai A. Rational design of therapeutics targeting the BCL-2 family: are some cancer cells primed for death but waiting for a final push? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 615:159-75. [PMID: 18437895 DOI: 10.1007/978-1-4020-6554-5_8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
A mechanism for circumventing apoptosis prevalent in many cancer cells is the overexpression of antiapoptotic BCL-2 family members. Upregulated expression of BCL-2 may be required to permit ongoing death signaling without a cellular response. Therefore, antagonizing BCL-2 function may cause death in many cancer cells. The selection for expression of BCL-2 or other antiapoptotic proteins during oncogenesis may derive from these proteins' ability to bind and sequester proapoptotic BH3-only proteins. This situation may be advantageous from a therapeutic viewpoint because cancer cells may be distinguished from normal cells by being primed with death signals. There are several strategies currently under investigation that may lead to improved treatment of many cancers by taking advantage of these differences.
Collapse
Affiliation(s)
- Victoria Del Gaizo Moore
- Medical Oncology, Dana-Farber Cancer Institute, 44 Binney Street, Dana 530B, Boston, MA 02115, USA
| | | |
Collapse
|
29
|
Trudel S, Li ZH, Rauw J, Tiedemann RE, Wen XY, Stewart AK. Preclinical studies of the pan-Bcl inhibitor obatoclax (GX015-070) in multiple myeloma. Blood 2007; 109:5430-8. [PMID: 17332241 DOI: 10.1182/blood-2006-10-047951] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Abstract
Bcl family members Bcl-2, Bcl-xL, and Mcl-1, are frequently expressed and implicated in the survival of myeloma cells. Obatoclax (GX015-070) is a novel, small-molecule antagonist of the BH3-binding groove of the Bcl family of proteins. We show that GX015-070 inhibits the binding of Bak to Mcl-1, up-regulates Bim, induces cytochrome c release, and activates capase-3 in human myeloma cell lines (HMCLs), confirming the predicted mechanism of action. Consequently, GX015-070 potently inhibited the viability of 15 of 16 HMCLs (mean IC50 of 246 nM), including those resistant to melphalan and dexamethasone. In combination studies, GX015-070 enhanced the antimyeloma activity induced by melphalan, dexamethasone, or bortezomib. Sensitivity to GX015-070 correlated with the absence or near absence of Bcl-xL. Coculture with interleukin-6 or adherence to bone marrow stroma conferred modest resistance; however, it did not overcome GX015-070–induced cytotoxicity. Of importance, GX015-070 as a single agent induced potent cytotoxic responses against patient-derived tumor cells. GX015-070 inhibited normal bone marrow–derived colony formation; however, cytotoxicity to human blood lymphocytes was not observed. Taken together, these studies describe a novel BH3 mimic with selectivity for Mcl-1, and support the therapeutic application of GX015-070 for diverse neoplasias including multiple myeloma.
Collapse
Affiliation(s)
- Suzanne Trudel
- Hematology-Oncology, Princess Margaret Hospital, Toronto, ON, Canada
| | | | | | | | | | | |
Collapse
|
30
|
Mansour A, Chang VT, Srinivas S, Harrison J, Raveche E. Correlation of ZAP-70 expression in B cell leukemias to the ex vivo response to a combination of fludarabine/genistein. Cancer Immunol Immunother 2007; 56:501-14. [PMID: 17051411 PMCID: PMC11030053 DOI: 10.1007/s00262-006-0207-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Accepted: 07/07/2006] [Indexed: 12/16/2022]
Abstract
The role of ZAP-70 expression on the ex vivo response of blood cells from CLL and PLL patients to a combination of fludarabine, a purine analog, and genistein, a tyrosine kinase inhibitor was studied. Patient cells were studied for the expression of ZAP-70 mRNA and its relation to the induction of apoptosis in response to treatment with genistein 15-60 muM and/or fludarabine 3 muM. The combination of genistein and fludarabine resulted in a significantly increased induction of apoptosis relative to the fludarabine alone. The ex vivo patient cells with a high ZAP-70 expression underwent more apoptosis in response to genistein than did patient cells with a low ZAP-70 mRNA expression. In contrast, basal IL-10 mRNA expression correlated negatively with apoptosis induction in response to genistein (P < 0.01). These studies suggest that, in malignant B cells that express elevated levels of the ZAP-70 signaling molecule, genistein may inhibit the ZAP-70 tyrosine kinase activity, resulting in cell death. The ZAP-70 may serve as a target for therapy. In addition, these studies suggest that the IL-10 expression by malignant B cells may not only suppress anti-tumor T cell responses in vivo, but also promote the survival of malignant B cells despite treatment with chemotherapeutic agents.
Collapse
Affiliation(s)
- Amal Mansour
- Department of Pathology, New Jersey Medical School, UMDNJ, Newark, NJ USA
| | - Victor T. Chang
- Department of Pathology, New Jersey Medical School, UMDNJ, Newark, NJ USA
- Section of Hematology/Oncology, VA New Jersey Health Care System, East Orange, NJ USA
- Department of Medicine, New Jersey Medical School, UMDNJ, Newark, NJ USA
| | - Shanti Srinivas
- Department of Pathology, New Jersey Medical School, UMDNJ, Newark, NJ USA
- Section of Hematology/Oncology, VA New Jersey Health Care System, East Orange, NJ USA
- Department of Medicine, New Jersey Medical School, UMDNJ, Newark, NJ USA
| | - Jonathan Harrison
- Department of Pathology, New Jersey Medical School, UMDNJ, Newark, NJ USA
| | - Elizabeth Raveche
- Department of Pathology, New Jersey Medical School, UMDNJ, Newark, NJ USA
- Department of Pathology and Laboratory Medicine, New Jersey Medical School,, UMDNJ, MSB C512, 185 S. Orange Avenue, Newark, NJ 07103 USA
| |
Collapse
|
31
|
Shi Y, White D, He L, Miller RL, Spaner DE. Toll-like receptor-7 tolerizes malignant B cells and enhances killing by cytotoxic agents. Cancer Res 2007; 67:1823-31. [PMID: 17308125 DOI: 10.1158/0008-5472.can-06-2381] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chronic activation through Toll-like receptors (TLR) occurs in a number of pathologic settings, but has not been studied to the same extent as primary activation. TLR7, expressed by B cells and some dendritic cells, recognizes molecular patterns associated with viruses that can be mimicked by synthetic imidazoquinolines. In response to primary stimulation with the imidazoquinoline, S28690, human mononuclear cells produced tumor necrosis factor-alpha, but were unable to do so upon restimulation with S28690. This state of "tolerization" lasted at least 5 days. Using chronic lymphocytic leukemia B cells as a model to facilitate biochemical analysis, the tolerized state was found to be associated with altered receptor components, including down-regulated expression of TLR7 mRNA and decreased levels of interleukin-1 receptor-associated kinase 1. Tolerization was characterized by a transcriptionally regulated block in stress-activated protein kinase and nuclear factor kappaB activation, with relatively preserved activation of extracellular signal-regulated kinase (ERK). Tolerized chronic lymphocytic leukemia cells were found to be more sensitive to cytotoxic chemotherapeutic agents, in part through altered stress-activated protein kinase signaling pathways. This property of the TLR7-tolerized state may potentially be exploited in the treatment of B cell cancers.
Collapse
MESH Headings
- Aged
- Aged, 80 and over
- B-Lymphocytes/drug effects
- B-Lymphocytes/pathology
- Drug Resistance, Neoplasm
- Female
- Humans
- Imidazoles/pharmacology
- Interleukin-1 Receptor-Associated Kinases/biosynthesis
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/metabolism
- Male
- Middle Aged
- Quinolines/pharmacology
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Signal Transduction
- Toll-Like Receptor 7/agonists
- Toll-Like Receptor 7/biosynthesis
- Toll-Like Receptor 7/physiology
- Transcription, Genetic
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/genetics
- Vincristine/pharmacology
Collapse
Affiliation(s)
- Yonghong Shi
- Division of Molecular and Cellular Biology, Research Institute, Sunnybrook Health Sciences Center, 2075 Bayview Avenue, Toronto, Ontario, Canada
| | | | | | | | | |
Collapse
|
32
|
Abstract
Defects in the core machinery of the apoptosis pathway contribute to chemoresistance and poor outcomes in patients with acute leukemia. To overcome these defects, novel molecules that target key proteins in the apoptosis pathway are being developed. This review highlights compounds that target the mitochondrial, death receptor, and convergence pathways of caspase activation that are being developed for the treatment of acute leukemia.
Collapse
Affiliation(s)
- Aaron D Schimmer
- Princess Margaret Hospital, Room 9-516, 610 University Avenue, Toronto, ON, M5G 2M9, Canada.
| |
Collapse
|
33
|
Wang M, Johansen B, Nissen MH, Thorn M, Kløverpris H, Fomsgaard A, Buus S, Claësson MH. Identification of an HLA-A*0201 restricted Bcl2-derived epitope expressed on tumors. Cancer Lett 2006; 251:86-95. [PMID: 17182178 DOI: 10.1016/j.canlet.2006.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 11/01/2006] [Accepted: 11/06/2006] [Indexed: 11/27/2022]
Abstract
A large number of human tumor-associated antigen-derived peptides have been identified that are recognized by CTLs in a MHC-I restricted fashion. The apoptosis inhibitory protein Bcl2 is overexpressed in many human cancers as part of their neoplastic phenotype. Since inhibition or loss of Bcl2 expression might impair tumor growth and survival, this protein may serve as a rational target for vaccine-induced CTL responses. By Western blot technique, we screened a panel of established human tumor cell lines for proteins involved in the apoptotic process. Two of eight tumor cell lines, a B lymphoma (Loukes) and a colon carcinoma (CCL220) cell line showed increased Bcl2 protein expression whereas the majority of tumor cell lines expressed proapoptotic proteins. Neither fibroblasts nor peripheral blood mononuclear cells showed Bcl2 expression. An HLA-A*0201 restricted CTL epitope was deduced in silica from the amino acid sequence of the Bcl2 protein and its binding affinity for HLA-A*0201 was confirmed using a biochemical binding assay. We here demonstrate that the 9-mer peptide Bcl2(85-93) induces specific CTL reactivity in immunized C57-A2K(b) or -A2D(b) tg mice. These Bcl2(85-93) specific CTLs react with and lyse Bcl2-expressing human colon carcinoma CCL220 cells which have been transfected with a chimeric HLA-A*0201/H2-K(b) DNA construct similar to that expressed in the transgenic mice. Based on these observations, we suggest that Bcl2(85-93) may be a target for immune therapy.
Collapse
Affiliation(s)
- Mingjun Wang
- Laboratory of Cellular Immunology, Department of Medical Anatomy, The Panum Institute, University of Copenhagen, Blegdamsvej 3C, DK-2200 Copenhagen N, Denmark
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Spaner DE, Masellis A. Toll-like receptor agonists in the treatment of chronic lymphocytic leukemia. Leukemia 2006; 21:53-60. [PMID: 17066089 DOI: 10.1038/sj.leu.2404456] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Advances in our understanding of the Toll-like receptors (TLRs) have led to the identification of several agonists that are suitable for clinical development. Chronic lymphocytic leukemia (CLL) may be especially amenable to TLR agonists because it is an immunologically susceptible tumor with strong expression of several TLRs, particularly TLR-7 and TLR-9. TLR agonists may indirectly clear CLL cells by enhancing the activity of natural killer and tumor-reactive T cells, or by altering the tumor microenvironment and inhibiting angiogenesis. However, signaling pathways can be activated directly in CLL cells by TLR-7 and TLR-9 agonists, leading to the production of cytokines and costimulatory molecules in a manner that is dependent on the underlying cytogenetic abnormalities, but rendering the tumor cells more sensitive to killing by cytotoxic T cells, immunotoxins and some chemotherapeutic drugs. Imidazoquinolines are TLR-7 agonists with strong local activity against CLL, and phase I trials of systemically administered imidazoquinolines (and also cytosine-phosphate-guanosine oligonucleotides that are TLR-9 agonists) are currently ongoing at different centers. The potential importance of these TLR agonists in the treatment of CLL is suggested by their ability to sensitize tumor cells to cytotoxic agents, and their future probably lies in combination with radiotherapies, chemotherapies, monoclonal antibodies and cancer vaccines.
Collapse
MESH Headings
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Cell Death/drug effects
- Clinical Trials as Topic
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/immunology
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Oligonucleotides/pharmacology
- Oligonucleotides/therapeutic use
- Quinolones/pharmacology
- Quinolones/therapeutic use
- T-Lymphocytes, Cytotoxic/immunology
- Toll-Like Receptor 7/agonists
- Toll-Like Receptor 9/agonists
Collapse
Affiliation(s)
- D E Spaner
- Division of Molecular and Cellular Biology, Research Institute, Sunnybrook and Women's College Health Sciences Center, Toronto, Ontario, Canada.
| | | |
Collapse
|
35
|
Kim R, Emi M, Matsuura K, Tanabe K. Antisense and nonantisense effects of antisense Bcl-2 on multiple roles of Bcl-2 as a chemosensitizer in cancer therapy. Cancer Gene Ther 2006; 14:1-11. [PMID: 17041564 DOI: 10.1038/sj.cgt.7700986] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Bcl-2 is an oncoprotein that plays a critical role in inhibiting apoptotic cell death in the mitochondria-dependent pathway in cancer chemotherapy. As a strategy for blocking Bcl-2 for enhancement of the chemotherapeutic effect, antisense Bcl-2 (AS Bcl-2; G3139, oblimersen sodium, Genasense) has shown promise, and there are several ongoing clinical studies with hematological malignancies as well as solid tumors. Although several preclinical and clinical studies have shown the therapeutic efficacy of Bcl-2 in combination with an anticancer drug as a chemosensitizer, in clinical trials the downregulation of Bcl-2 has not been observed with a high frequency in tumor cells. Nevertheless, previous studies showed nonantisense effects such as production of reactive oxygen species and immunostimulatory action through cytosine-phosphate-guanosine-motif in the antisense oligodeoxynucleotides. Further, Bcl-2 is able to inhibit Beclin 1-dependent autophagic cell death, which is a nonapoptotic cell death. The current status and future directions of AS Bcl-2 and the potential mechanisms for multiple roles that Bcl-2 has in cancer therapy are reviewed.
Collapse
Affiliation(s)
- R Kim
- International Radiation Information Center, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
| | | | | | | |
Collapse
|
36
|
Ruiz S, Krupnik Y, Keating M, Chandra J, Palladino M, McConkey D. The proteasome inhibitor NPI-0052 is a more effective inducer of apoptosis than bortezomib in lymphocytes from patients with chronic lymphocytic leukemia. Mol Cancer Ther 2006; 5:1836-43. [PMID: 16891470 DOI: 10.1158/1535-7163.mct-06-0066] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Proteasome inhibitors are potent inducers of apoptosis in isolated lymphocytes from patients with chronic lymphocytic leukemia (CLL). However, the reversible proteasome inhibitor bortezomib (PS-341; Velcade) did not display substantial antitumor activity in CLL patients. Here, we compared the effects of bortezomib and a new irreversible proteasome inhibitor (NPI-0052) on 20S chymotryptic proteasome activity and apoptosis in isolated CLL cells in vitro. Although their steady-state (3 hours) IC(50)s as proteasome inhibitors were similar, NPI-0052 exerted its effects more rapidly than bortezomib, and drug washout experiments showed that short exposures to NPI-0052 resulted in sustained (> or =24 hours) 20S proteasome inhibition, whereas 20S activity recovered in cells exposed to even 10-fold higher concentrations of bortezomib. Thus, brief (15 minutes) pulses of NPI-0052 were sufficient to induce substantial apoptosis in CLL cells, whereas longer exposure times (> or =8 hours) were required for commitment to apoptosis in cells exposed to equivalent concentrations of bortezomib. Commitment to apoptosis seemed to be related to caspase-4 activation, in that cells exposed to bortezomib or NPI-0052 could be saved from death by addition of a selective caspase-4 inhibitor up to 8 hours after drug exposure. Our results show that NPI-0052 is a more effective proapoptotic agent than bortezomib in isolated CLL cells and suggest that the chemical properties of NPI-0052 might also make it an effective therapeutic agent in CLL patients.
Collapse
Affiliation(s)
- Stacey Ruiz
- Department of Cancer Biology, The University of Texas M.D. Anderson Cancer Center, Box 173, 1515 Holcombe Boulevard, Houston, TX 77030, USA
| | | | | | | | | | | |
Collapse
|
37
|
Nakagawa R, Soh JW, Michie AM. Subversion of protein kinase C alpha signaling in hematopoietic progenitor cells results in the generation of a B-cell chronic lymphocytic leukemia-like population in vivo. Cancer Res 2006; 66:527-34. [PMID: 16397269 DOI: 10.1158/0008-5472.can-05-0841] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
B-cell chronic lymphocytic leukemia (B-CLL) is characterized by the accumulation of long-lived mature B cells with the distinctive phenotype CD19(hi) CD5+ CD23+ IgM(lo), which are refractory to apoptosis. An increased level of apoptosis has been observed on treatment of human B-CLL cells with protein kinase C (PKC) inhibitors, suggesting that this family of protein kinases mediate survival signals within B-CLL cells. Therefore, to investigate the ability of individual PKC isoforms to transform developing B cells, we stably expressed plasmids encoding PKC mutants in fetal liver-derived hematopoietic progenitor cells (HPC) from wild-type mice and then cultured them in B-cell generation systems in vitro and in vivo. Surprisingly, we noted that expression of a plasmid-encoding dominant-negative PKC alpha (PKC alpha-KR) in HPCs and subsequent culture both in vitro and in vivo resulted in the generation of a population of cells that displayed an enhanced proliferative capacity over untransfected cells and phenotypically resemble human B-CLL cells. In the absence of growth factors and stroma, these B-CLL-like cells undergo cell cycle arrest and, consistent with their ability to escape growth factor withdrawal-induced apoptosis, exhibited elevated levels of Bcl-2 expression. These studies therefore identify a unique oncogenic trigger for the development of a B-CLL-like disease resulting from the subversion of PKC alpha signaling. Our findings uncover novel avenues not only for the study of the induction of leukemic B cells but also for the development of therapeutic drugs to combat PKC alpha-regulated transformation events.
Collapse
Affiliation(s)
- Rinako Nakagawa
- Division of Immunology, Infection and Inflammation, Western Infirmary, University of Glasgow, Scotland, United Kingdom
| | | | | |
Collapse
|
38
|
Liu J, Huang R, Lin D, Wu X, Peng J, Lin Q, Pan X, Zhang M, Hou M, Chen F. Apoptotic effect of oridonin on NB4 cells and its mechanism. Leuk Lymphoma 2005; 46:593-7. [PMID: 16019488 DOI: 10.1080/10428190400019800] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The anti-proliferation effects of oridonin on acute promyelocytic leukemia (APL) cells and its mechanisms were studied in vitro. NB4 cells as well as fresh leukemia cells obtained from APL patients in culture medium were treated with different concentrations of oridonin. Cell growth inhibition, apoptosis and related pathways were assessed by MTT assay as well as flow cytometry (FCM) and western blot analysis. The data revealed that oridonin (over 16 micromol/L) could inhibit the growth of NB4 cells by induction of apoptosis. Marked changes of cell apoptosis were observed very clearly by using electron microscopy and DNA fragmentation analysis after the cells exposed to oridonin for 48 h; Western blotting showed cleavage of the caspase-3 zymogen protein (32-kDa) with the appearance of its 20-kDa subunit as well as a cleaved 89-kDa fragment of 116-kDa PARP when apoptosis occurred. The expression of Bcl-2 was down-regulated remarkably accompanied by the disruption of the mitochondrial membrane potential (delta(psi)m). The anti-proliferative and apoptosis-inducing effects by oridonin in fresh APL cells were also found remarkably using Trypan Blue dye exclusion method and Wright's staining. We concluded that oridoning has significant anti-proliferative and apoptosis-inducing effects on NB4 cells by activation of caspase-3 and cleavage of PARP as well as by down regulation of Bcl-2 and disruption of the delta(psi)m. Furthermore, oridonin demonstrated apparent cell growth inhibition effects on fresh APL cells in vitro. The results indicated that oridonin may serve as a potential anti-leukemia reagent.
Collapse
MESH Headings
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- Blotting, Western
- Caspase 3
- Caspases/drug effects
- Caspases/metabolism
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Diterpenes/pharmacology
- Diterpenes, Kaurane
- Dose-Response Relationship, Drug
- Drug Screening Assays, Antitumor
- Humans
- Leukemia, Promyelocytic, Acute/chemically induced
- Leukemia, Promyelocytic, Acute/drug therapy
- Leukemia, Promyelocytic, Acute/metabolism
- Molecular Structure
- Proto-Oncogene Proteins c-bcl-2/drug effects
- Proto-Oncogene Proteins c-bcl-2/metabolism
Collapse
Affiliation(s)
- Jiajun Liu
- Department of Hematology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, People's Republic of China.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Nückel H, Frey UH, Röth A, Dührsen U, Siffert W. Alemtuzumab induces enhanced apoptosis in vitro in B-cells from patients with chronic lymphocytic leukemia by antibody-dependent cellular cytotoxicity. Eur J Pharmacol 2005; 514:217-24. [PMID: 15910809 DOI: 10.1016/j.ejphar.2005.03.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2004] [Revised: 03/08/2005] [Accepted: 03/16/2005] [Indexed: 10/25/2022]
Abstract
Alemtuzumab, a monoclonal anti-CD52 antibody has been shown to be highly effective in B-cell chronic lymphocytic leukemia, even in fludarabine-refractory disease. The mechanism of action is currently unknown, but may rely on complement-mediated cell lysis and antibody-dependent cellular cytotoxicity. The aim of this study was to assess the proapoptotic activity of alemtuzumab in chronic lymphocytic leukemia and to describe pathways potentially underlying this effect. Peripheral blood mononuclear cells from 21 chronic lymphocytic leukemia patients were treated in vitro in the absence of complement with fludarabine alone, alemtuzumab alone, or with the additional presence of a cross-linking anti-Fc-antibody. Apoptosis was quantified after 24 h by flow cytometry analysis. Expression of several pro- and anti-apoptotic proteins was determined at different time points. Apoptosis of peripheral blood mononuclear cells treated with alemtuzumab alone was significantly enhanced compared to untreated cells suggesting a minor potentially cytotoxic mechanism by direct signaling independent from antibody-dependent cellular cytotoxicity. The presence of a cross-linking anti-Fc-antibody induced the formation of cell clusters and enhanced apoptosis significantly suggesting a potential role of antibody-dependent cellular cytotoxicity in alemtuzumab induced apoptosis. Alemtuzumab activated a CD52-dependent signaling pathway which induced a significant increase in caspase 3 and 8 expression. Alemtuzumab significantly enhances apoptosis in chronic lymphocytic leukemia cells in vitro, especially in combination with a cross-linking anti-Fc-antibody, this effect being mediated by a caspase-dependent pathway.
Collapse
MESH Headings
- Alemtuzumab
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal, Humanized
- Antibodies, Neoplasm/pharmacology
- Antineoplastic Agents/pharmacology
- Apoptosis/drug effects
- B-Lymphocytes/drug effects
- B-Lymphocytes/immunology
- B-Lymphocytes/metabolism
- Blotting, Western
- Caspase 3
- Caspase 9
- Caspases/metabolism
- Cell Aggregation/drug effects
- Cell Survival/drug effects
- Cells, Cultured
- Female
- Flow Cytometry
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/blood
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Male
- Middle Aged
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Vidarabine/analogs & derivatives
- Vidarabine/pharmacology
- bcl-2-Associated X Protein
Collapse
Affiliation(s)
- Holger Nückel
- Department of Hematology, Medical School, University of Duisburg-Essen, Germany.
| | | | | | | | | |
Collapse
|
40
|
Jahrsdörfer B, Wooldridge JE, Blackwell SE, Taylor CM, Link BK, Weiner GJ. Good prognosis cytogenetics in B-cell chronic lymphocytic leukemia is associated in vitro with low susceptibility to apoptosis and enhanced immunogenicity. Leukemia 2005; 19:759-66. [PMID: 15759034 DOI: 10.1038/sj.leu.2403694] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chromosomal abnormalities in B-cell chronic lymphocytic leukemia (B-CLL) have been shown to correlate with prognosis. Little is known about the relationship between chromosomal abnormalities and biological behavior of B-CLL cells in vitro. The present study was designed to explore the impact of chromosomal abnormalities determined by interphase fluorescence in situ hybridization (FISH) on the in vitro survival and immunogenicity of B-CLL. Considerable heterogeneity was noted in the in vitro survival and expression of costimulatory, adhesion, and antigen-presenting molecules by B-CLL cells. Spontaneous apoptosis of B-CLL cells in vitro was significantly lower in samples with good prognosis cytogenetics when compared to samples with poor prognosis cytogenetics. In contrast, B-CLL cells from samples with good prognosis cytogenetics exhibited higher basal expression of molecules involved in costimulation, cellular adhesion, and antigen presentation, and induced significantly more T-cell proliferation in mixed lymphocyte cultures. We conclude that chromosomal aberrations of B-CLL cells correlate with the in vitro biological behavior of B-CLL. Our data indicate that good prognosis cytogenetics correlates with less spontaneous apoptosis but greater in vitro immunogenicity. These findings could have significant implications on the design of future therapeutic approaches in patients with CLL, and the likelihood of response based on cytogenetics.
Collapse
Affiliation(s)
- B Jahrsdörfer
- Department of Internal Medicine, The Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242, USA
| | | | | | | | | | | |
Collapse
|
41
|
Andersen MH, Becker JC, Straten PT. Regulators of apoptosis: suitable targets for immune therapy of cancer. Nat Rev Drug Discov 2005; 4:399-409. [PMID: 15864269 DOI: 10.1038/nrd1717] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Harnessing the immune system in the battle against cancer has been the focus of tremendous research efforts during the past two decades. Several means for achieving this goal, including adoptive transfer of tumour-reactive T cells, systemic or localized administration of immune modulating cytokines and the use of 'therapeutic' vaccines, have been explored. Anti-apoptotic molecules that enhance the survival of cancer cells and facilitate their escape from cytotoxic therapies represent prime candidates as vaccination antigens. Notably, spontaneous cellular immune responses against these proteins have frequently been identified in cancer patients. Here, we summarize current knowledge of IAP and BCL2 family proteins as T-cell antigens, report the results of the first explorative trial using these antigens in therapeutic vaccinations against cancer and discuss future opportunities.
Collapse
Affiliation(s)
- Mads Hald Andersen
- Tumor Immunology Group, Institute of Cancer Biology, Danish Cancer Society, Strandboulevarden 49, Dk-2100 Copenhagen, Denmark.
| | | | | |
Collapse
|
42
|
Nishio M, Endo T, Tsukada N, Ohata J, Kitada S, Reed JC, Zvaifler NJ, Kipps TJ. Nurselike cells express BAFF and APRIL, which can promote survival of chronic lymphocytic leukemia cells via a paracrine pathway distinct from that of SDF-1alpha. Blood 2005; 106:1012-20. [PMID: 15860672 PMCID: PMC1895149 DOI: 10.1182/blood-2004-03-0889] [Citation(s) in RCA: 223] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We examined expression of B cell-activating factor of the tumor necrosis factor (TNF) family (BAFF) and a proliferation-inducing ligand (APRIL) on chronic lymphocytic leukemia (CLL) B cells and nurselike cells (NLCs), which differentiate from CD14+ cells when cultured with CLL B cells. NLCs expressed significantly higher levels of APRIL than monocytes and significantly higher levels of BAFF and APRIL than CLL B cells. Also, the viability of CLL B cells cultured with NLCs was significantly reduced when CLL B cells were cultured with decoy receptor of B-cell maturation antigen (BCMA), which can bind both BAFF and APRIL, but not with BAFF receptor:Fc (BAFF-R:Fc), which binds only to BAFF. The effect(s) of BAFF or APRIL on leukemia cell survival appeared additive and distinct from that of stromal cell-derived factor-1alpha (SDF-1alpha), which in contrast to BAFF or APRIL induced leukemia cell phosphorylation of p44/42 mitogen-activated protein kinase (extracellular signal-regulated kinase-1/2 [ERK1/2]) and AKT. Conversely, BAFF and APRIL, but not SDF-1alpha, induced CLL-cell activation of the nuclear factor-kappaB1 (NF-kappaB1) and enhanced CLL-cell expression of the antiapoptotic protein Mcl-1. However, BAFF, but not APRIL, also induced CLL-cell activation of NF-kappaB2. We conclude that BAFF and APRIL from NLCs can function in a paracrine manner to support leukemia cell survival via mechanisms that are distinct from those of SDF-1alpha, indicating that NLCs use multiple distinct pathways to support CLL-cell survival.
Collapse
MESH Headings
- B-Cell Activation Factor Receptor
- Cell Differentiation
- Cell Survival
- Chemokine CXCL12
- Chemokines, CXC
- Coculture Techniques
- Gene Expression Regulation, Neoplastic
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukocytes, Mononuclear/chemistry
- Leukocytes, Mononuclear/physiology
- Lipopolysaccharide Receptors
- Membrane Proteins/analysis
- Membrane Proteins/genetics
- Membrane Proteins/physiology
- NF-kappa B/metabolism
- NF-kappa B p50 Subunit
- NF-kappa B p52 Subunit
- Paracrine Communication
- Protein Precursors/metabolism
- RNA, Messenger/analysis
- Receptors, Tumor Necrosis Factor/analysis
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Tumor Necrosis Factor Ligand Superfamily Member 13
- Tumor Necrosis Factor-alpha/analysis
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/physiology
Collapse
Affiliation(s)
- Mitsufumi Nishio
- Department of Medicine, 9500 Gilman Dr, UCSD School of Medicine, La Jolla, CA 92093-0663, USA
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Packham G, Stevenson FK. Bodyguards and assassins: Bcl-2 family proteins and apoptosis control in chronic lymphocytic leukaemia. Immunology 2005; 114:441-9. [PMID: 15804279 PMCID: PMC1782118 DOI: 10.1111/j.1365-2567.2005.02117.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Chronic lymphocytic leukaemia (CLL) is the most common B-cell malignancy in the Western world and exists as subtypes with very different clinical courses. CLL is generally described as a disease of failed apoptosis. Apoptosis resistance may stem from a combination of microenvironmental survival signals as well as from intrinsic alterations in the apoptotic machinery within the CLL cell. The molecular mechanism involved in controlling apoptosis in CLL is complex and is influenced by many factors, including Bcl-2 family proteins, which are critical regulators of cell death. Here we review the significance of apoptosis dysregulation in CLL, focusing on the role of Bcl-2 and related Bcl-2 family proteins, such as Bax and Mcl-1. The differential properties of the newly described subsets of CLL are also highlighted.
Collapse
Affiliation(s)
- Graham Packham
- Cancer Research UK Oncology Unit, University of Southampton School of Medicine, Southampton General Hospital, Southampton, UK.
| | | |
Collapse
|
44
|
Andersen MH, Svane IM, Kvistborg P, Nielsen OJ, Balslev E, Reker S, Becker JC, Straten PT. Immunogenicity of Bcl-2 in patients with cancer. Blood 2005; 105:728-34. [PMID: 15367432 DOI: 10.1182/blood-2004-07-2548] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
AbstractB-cell lymphoma 2 (Bcl-2) is a pivotal regulator of apoptotic cell death and it is overexpressed in many cancers. Consequently, the Bcl-2 protein is an attractive target for drug design, and Bcl-2–specific antisense oligonucleotides or small-molecule Bcl-2 inhibitors have shown broad anticancer activities in preclinical models and are currently in several clinical trials. The clinical application of immunotherapy against cancer is rapidly moving forward in multiple areas, including the adoptive transfer of anti–tumor-reactive T cells and the use of “therapeutic” vaccines. The overexpression of Bcl-2 in cancer and the fact that immune escape by down-regulation or loss of expression of this protein would impair sustained tumor growth makes Bcl-2 a very attractive target for anticancer immunotherapy. Herein, we describe spontaneous T-cell reactivity against Bcl-2 in peripheral blood from patients suffering from unrelated tumor types (ie, pancreatic cancer, breast cancer, acute myeloid leukemia [AML], and chronic lymphocytic leukemia [CLL]). Additionally, we show that these Bcl-2–reactive T cells are indeed peptide-specific, cytotoxic effector cells. Thus, Bcl-2 may serve as an important and widely applicable target for anticancer immunotherapeutic strategies (eg, in the combination with conventional radiotherapy and chemotherapy).
Collapse
Affiliation(s)
- Mads Hald Andersen
- Tumor Immunology Group, Institute of Cancer Biology, Danish Cancer Society, Copenhagen, Demmark.
| | | | | | | | | | | | | | | |
Collapse
|
45
|
Kim R, Emi M, Tanabe K, Toge T. Preclinical evaluation of antisense bcl-2 as a chemosensitizer for patients with gastric carcinoma. Cancer 2004; 101:2177-86. [PMID: 15476281 DOI: 10.1002/cncr.20636] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Because bcl-2 is a critical factor for anticancer drug-induced apoptosis, the authors conducted a preclinical evaluation of antisense (AS) bcl-2 as an enhancer of the chemotherapeutic effect in the treatment of patietns with gastric carcinoma. METHODS AS bcl-2 was used with 18-mer phosphorothiated oligonucleotides in the MKN-45 gastric carcinoma cell line. Drug sensitivity in vitro was evaluated using the methyl-thiazoldiphenyl tetrazolium assay, and antitumor effects in vivo were evaluated using the nude mouse xenograft. Apoptosis was determined with the terminal deoxyuridine triphosphate nick-end labeling assay. AS bcl-2 in vitro was treated with lipofectin, whereas it was administered intraperitoneally for 6 consecutive days twice every 2 weeks in vivo. Anticancer drugs were administered intraperitoneally four times per week. RESULTS bcl-2 was down-regulated to 60% of its initial value after treatment with 1.0 muM AS bcl-2 compared with the controls of random and mismatched oligonucleotides. Drug sensitivity to doxorubicin, cisplatin, and paclitaxel (TXL) was increased 3-4-fold when used in combination with AS bcl-2, which was determined with 50% inhibitory concentration values, compared with the control group. Increased drug sensitivity was associated with apoptosis, which increased in Bax and poly-adenosine diphosphate (ADP-ribose) polymerase and decreased in phosphorylated Akt (pAkt). The antitumor effect of cisplatin and TXL in vivo was enhanced significantly in combination with AS bcl-2. Down-regulation of bcl-2 was observed on Day 4 after the treatment with AS bcl-2. CONCLUSIONS Combination treatment with AS bcl-2 and anticancer drugs, including cisplatin and TXL, may be a new strategy for enhancing chemotherapeutic effects in the treatment of gastric carcinoma.
Collapse
Affiliation(s)
- Ryungsa Kim
- Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
| | | | | | | |
Collapse
|
46
|
Shanafelt TD, Lee YK, Bone ND, Strege AK, Narayanan VL, Sausville EA, Geyer SM, Kaufmann SH, Kay NE. Adaphostin-induced apoptosis in CLL B cells is associated with induction of oxidative stress and exhibits synergy with fludarabine. Blood 2004; 105:2099-106. [PMID: 15388586 DOI: 10.1182/blood-2004-06-2205] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
B-cell chronic lymphocytic leukemia (CLL) is characterized by accumulation of clonal lymphocytes resistant to apoptosis. We evaluated the ability of the investigational antileukemic agent adaphostin to induce apoptosis in CLL B cells and synergize with fludarabine in vitro. Analysis by annexin V/propidium iodide (PI) staining revealed that the concentration of adaphostin required to induce 50% cell death (IC50) at 24 hours was 4.2 microM (range, 1.10-11.25 microM; median, 4.25 microM; n=29) for CLL isolates and more than 10 microM for B and T cells from healthy donors. Immunoblots demonstrated adaphostin induced poly(adenosine diphosphate-ribose) polymerase (PARP) cleavage and cleavage of caspase-3 substrates, suggesting that adaphostin induces apoptosis. Adaphostin increased the level of reactive oxygen species (ROS) within CLL B cells, and the antioxidant N-acetylcysteine blocked both adaphostin-induced ROS generation and apoptosis. Adaphostin also caused a decrease in the level of the antiapoptotic protein Bcl-2. When adaphostin was combined with fludarabine (F-ARA-AMP), a synergistic effect on cell death was observed in all 10 CLL samples. These findings not only indicate that adaphostin induces apoptosis selectively in CLL B cells through a mechanism that involves ROS generation but also demonstrate its ability to augment the effects of fludarabine. Further preclinical development of adaphostin as a novel agent for the treatment of CLL appears warranted.
Collapse
Affiliation(s)
- Tait D Shanafelt
- Department of Medicine, Division of Hematology, Mayo Clinic, 200 First St, SW, Rochester, MN 55905, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Rosato RR, Dai Y, Almenara JA, Maggio SC, Grant S. Potent antileukemic interactions between flavopiridol and TRAIL/Apo2L involve flavopiridol-mediated XIAP downregulation. Leukemia 2004; 18:1780-8. [PMID: 15385934 DOI: 10.1038/sj.leu.2403491] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Interactions between the cyclin-dependent kinase inhibitor flavopiridol (FP) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/Apo2L), were examined in human leukemia cells (U937 and Jurkat). Coexposure of cells to marginally toxic concentrations of TRAIL and FP (24 h) synergistically increased mitochondrial injury (eg, cytochrome c, AIF, Smac/DIABLO release), cytoplasmic depletion of Bax, activation of Bid as well as caspase-8 and -3, PARP cleavage, and apoptosis. Coadministration of TRAIL markedly increased FP-induced apoptosis in leukemic cells ectopically expressing Bcl-2, Bcl-x(L), or a phosphorylation loop-deleted form of Bcl-2 (DeltaBcl-2), whereas lethality was substantially attenuated in cells ectopically expressing CrmA, dominant-negative-FADD, or dominant-negative-caspase-8. TRAIL/FP induced no discernible changes in FLIP, DR4, DR5, Mcl-1, or survivin expression, modest declines in levels of DcR2 and c-IAP, but resulted in the marked transcriptional downregulation of XIAP. Moreover, cells stably expressing an XIAP-antisense construct exhibited a pronounced increase in TRAIL sensitivity comparable to degrees of apoptosis achieved with TRAIL/FP. Conversely, enforced XIAP expression significantly attenuated caspase activation and TRAIL/FP lethality. Together, these findings suggest that simultaneous activation of the intrinsic and extrinsic apoptotic pathways by TRAIL and FP synergistically induces apoptosis in human leukemia cells through a mechanism that involves FP-mediated XIAP downregulation.
Collapse
Affiliation(s)
- R R Rosato
- Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA 23298, USA
| | | | | | | | | |
Collapse
|
48
|
Schliep S, Decker T, Schneller F, Wagner H, Häcker G. Functional evaluation of the role of inhibitor of apoptosis proteins in chronic lymphocytic leukemia. Exp Hematol 2004; 32:556-62. [PMID: 15183896 DOI: 10.1016/j.exphem.2004.03.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2003] [Revised: 02/25/2004] [Accepted: 03/10/2004] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The slow accumulation of malignant cells in chronic lymphocytic leukemia (CLL) suggests a defect in the induction of apoptosis in these cells. Previous studies have found sporadic alterations in the apoptotic apparatus in CLL cells, but a widespread defect has not been detected until now. A crucial checkpoint in the progression of apoptosis is the activity of inhibitor of apoptosis proteins (IAP) that control the activity of caspases upon the release of cytochrome c from mitochondria. The aim of this study was to evaluate the role of IAP in the regulation of apoptosis in CLL cells. MATERIALS AND METHODS Lysates from CLL cells were prepared, and the regular function of components of the cytochrome c-dependent caspase-activating machinery (the apoptosome) was investigated. The effect of IAP in caspase-inhibition was tested using a peptide derived from the mitochondrial IAP antagonist Smac/DIABLO. Regulation of expression as well as inhibitory function of the X-linked IAP (XIAP) by cytokines was analyzed. RESULTS The apoptosome was found to be structurally and functionally competent in CLL. XIAP expression was enhanced by culture in the presence of cytokines. Smac/DIABLO was easily detectable in CLL cells and was released into the cytosol during apoptosis. No inhibitory effect of IAP was detected in CLL, irrespective of XIAP levels and culture conditions. CONCLUSION Although XIAP is present in CLL cells and is up-regulated in conditions where apoptosis is prevented, no caspase-inhibiting anti-apoptotic effect of IAP is detectable. This is likely due to the high expression of Smac/DIABLO in CLL cells that is sufficient to overcome the caspase-inhibiting effect of IAP.
Collapse
Affiliation(s)
- Stefan Schliep
- Institute for Medical Microbiology, Immunology and Hygiene, Technical University Munich, Munich, Germany
| | | | | | | | | |
Collapse
|
49
|
Abstract
Apoptosis, the cell's intrinsic death program, is a key regulator of tissue homeostasis. An imbalance between cell death and proliferation may result in tumor formation. Also, killing of cancer cells by cytotoxic therapies such as chemotherapy, gamma-irradiation or ligation of death receptors is predominantly mediated by triggering apoptosis in target cells. In addition to the intrinsic mitochondrial pathway, elements of death receptor signaling pathways have been implied to contribute to the efficacy of cancer therapy. Failure to undergo apoptosis in response to anticancer therapy may lead to resistance. Also, deregulated expression of death receptor pathway molecules may contribute to tumorigenesis and tumor escape from endogenous growth control. Understanding the molecular events that regulate apoptosis induced by anticancer therapy and how cancer cells evade apoptosis may provide new opportunities for pathway-based rational therapy and for drug development.
Collapse
|
50
|
Hahntow IN, Schneller F, Oelsner M, Weick K, Ringshausen I, Fend F, Peschel C, Decker T. Cyclin-dependent kinase inhibitor Roscovitine induces apoptosis in chronic lymphocytic leukemia cells. Leukemia 2004; 18:747-55. [PMID: 14973497 DOI: 10.1038/sj.leu.2403295] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A new class of cell cycle inhibitors is currently entering clinical trials. These drugs exert their activity by inhibition of cyclin-dependent kinases (cdk) and induce cell cycle arrest and apoptosis in cancer cells. Roscovitine, a cdk2-inhibitor that is in preclinical evaluation, induced apoptosis in B-CLL cells at doses that were not cytotoxic for normal human B cells. At 20 microM, Roscovitine induced apoptosis in 21 of 28 B-CLL samples and was equally effective in zap-70-positive or -negative samples. Caspase-3 was cleaved in B-CLL cells exposed to Roscovitine and the pancaspase inhibitor z.VAD.fmk-blocked Roscovitine-induced apoptosis. Expression of the proapoptotic protein Bak was increased and Bax cleavage and conformational change was observed in Roscovitine-treated B-CLL cells. Antiapoptotic proteins Mcl-1 and XIAP were downregulated, but the expression of Bcl-2 remained unchanged. In contrast to previous reports in cancer cell lines, Roscovitine treatment was not accompanied by nuclear accumulation of p53. Cyc202 (R-Roscovitine) is in early clinical trials in cancer patients. Given its powerful effects on zap-70-positive and -negative B-CLL cells, but not on normal lymphocytes, Roscovitine might be an attractive drug to be tested in this incurable disease.
Collapse
Affiliation(s)
- I N Hahntow
- Department of Medicine, Technical University of Munich, Munich, Germany
| | | | | | | | | | | | | | | |
Collapse
|