1
|
Jebaraj BMC, Stilgenbauer S. Telomere Dysfunction in Chronic Lymphocytic Leukemia. Front Oncol 2021; 10:612665. [PMID: 33520723 PMCID: PMC7844343 DOI: 10.3389/fonc.2020.612665] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/30/2020] [Indexed: 12/13/2022] Open
Abstract
Telomeres are nucleprotein structures that cap the chromosomal ends, conferring genomic stability. Alterations in telomere maintenance and function are associated with tumorigenesis. In chronic lymphocytic leukemia (CLL), telomere length is an independent prognostic factor and short telomeres are associated with adverse outcome. Though telomere length associations have been suggested to be only a passive reflection of the cell’s replication history, here, based on published findings, we suggest a more dynamic role of telomere dysfunction in shaping the disease course. Different members of the shelterin complex, which form the telomere structure have deregulated expression and POT1 is recurrently mutated in about 3.5% of CLL. In addition, cases with short telomeres have higher telomerase (TERT) expression and activity. TERT activation and shelterin deregulation thus may be pivotal in maintaining the minimal telomere length necessary to sustain survival and proliferation of CLL cells. On the other hand, activation of DNA damage response and repair signaling at dysfunctional telomeres coupled with checkpoint deregulation, leads to terminal fusions and genomic complexity. In summary, multiple components of the telomere system are affected and they play an important role in CLL pathogenesis, progression, and clonal evolution. However, processes leading to shelterin deregulation as well as cell intrinsic and microenvironmental factors underlying TERT activation are poorly understood. The present review comprehensively summarizes the complex interplay of telomere dysfunction in CLL and underline the mechanisms that are yet to be deciphered.
Collapse
Affiliation(s)
| | - Stephan Stilgenbauer
- Department of Internal Medicine III, University of Ulm, Ulm, Germany.,Klinik für Innere Medizin I, Universitätsklinikum des Saarlandes, Homburg, Germany
| |
Collapse
|
2
|
Palmitelli M, Stanganelli C, Stella F, Krzywinski A, Bezares R, González Cid M, Slavutsky I. Analysis of basal chromosome instability in patients with chronic lymphocytic leukaemia. Mutagenesis 2019; 34:245-252. [PMID: 31037299 DOI: 10.1093/mutage/gez009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 02/22/2019] [Accepted: 04/15/2019] [Indexed: 01/25/2023] Open
Abstract
Genomic instability is a hallmark of cancer, contributing to tumour development and transformation, being chromosome instability (CIN) the most common form in human cancer. Chronic lymphocytic leukaemia (CLL) is the most frequent adult leukaemia in the Western world. In this study, we have evaluated basal CIN in untreated patients with CLL by measuring chromosome aberrations (CAs) and micronucleus (MN) frequency and their association with different prognostic factors. Seventy-two patients and 21 normal controls were analysed. Cytogenetic and fluorescence in situ hybridisation (FISH) studies were performed. IGHV (immunoglobulin heavy chain variable region) mutational status was evaluated by reverse transcription polymerase chain reaction and sequencing. An increased number of CA in patients compared with controls (P = 0.0001) was observed. Cases with abnormal karyotypes showed increased CA rate than those with normal karyotypes (P = 0.0026), with a particularly highest frequency in cases with complex karyotypes. Among FISH risk groups, a significant low frequency of CA was found in patients with no FISH alterations compared to those with del13q14 and ≥2 FISH alterations (P = 0.0074). When mean CA value (6.7%) was considered, significant differences in the distribution of low and high CA frequency between cases with normal and abnormal karyotypes (P = 0.002) were observed. By MN analysis, higher frequency in patients compared to controls (P = 0.0001) was also found, as well as between cases with ≥2 FISH abnormalities and those with no FISH alterations (P = 0.026). Similarly, significant differences were observed when patients were divided according to mean MN frequency (2.2%; P ≤ 0.04). Interestingly, patients with high MN frequency had shorter time to first treatment than those with low frequency (P = 0.024). Cases with mutated and unmutated IGHV status showed increased CA and MN frequencies compared to controls (P ≤ 0.0007), but no differences between both groups were found. Our results support the strong interaction between CIN and genomic complexity as well as their influence on poor outcome in this pathology.
Collapse
Affiliation(s)
- Micaela Palmitelli
- Laboratorio de Mutagénesis, Instituto de Medicina Experimental, CONICET-Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Carmen Stanganelli
- División Patología Molecular, Instituto de Investigaciones Hematológicas, Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Flavia Stella
- Laboratorio de Genética de Neoplasias Linfoides, Instituto de Medicina Experimental, CONICET-Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Andrea Krzywinski
- Laboratorio de Genética de Neoplasias Linfoides, Instituto de Medicina Experimental, CONICET-Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Raimundo Bezares
- Servicio de Hematología, Hospital Teodoro Álvarez, Buenos Aires, Argentina
| | - Marcela González Cid
- Laboratorio de Mutagénesis, Instituto de Medicina Experimental, CONICET-Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Irma Slavutsky
- Laboratorio de Genética de Neoplasias Linfoides, Instituto de Medicina Experimental, CONICET-Academia Nacional de Medicina, Buenos Aires, Argentina
| |
Collapse
|
3
|
Short telomeres are associated with inferior outcome, genomic complexity, and clonal evolution in chronic lymphocytic leukemia. Leukemia 2019; 33:2183-2194. [PMID: 30911113 DOI: 10.1038/s41375-019-0446-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Revised: 01/19/2019] [Accepted: 02/11/2019] [Indexed: 11/08/2022]
Abstract
Telomere length in chronic lymphocytic leukemia (CLL) has been shown to be of prognostic importance, but the analyses have largely been executed on heterogeneous patient cohorts outside of clinical trials. In the present study, we performed a comprehensive analysis of telomere length associations in the well characterized CLL8 trial (n = 620) of the German CLL study group, with validation in a representative cohort of the CLL4 trial (n = 293). Absolute telomere length was analyzed using quantitative-PCR. Apart from identifying associations of short telomere length with adverse prognostic factors and survival, the study identified cases with 17p- and 11q- associated with TP53 and ATM loss, respectively, to have the shortest telomeres, even when these aberrations were present in small subclones. Thus, telomere shortening may precede acquisition of the high-risk aberrations, contributing to disease evolution. In line with this, telomere shortening was associated with an increase in genomic complexity as well as clonal evolution, highlighting its importance as a biomarker especially in monitoring disease progression in non-high-risk CLL.
Collapse
|
4
|
Kaifie A, Schikowsky C, Vasko T, Kraus T, Brümmendorf TH, Ziegler P. Additional benefits of telomere length (TL) measurements in chronic lymphocytic leukemia. Leuk Lymphoma 2018; 60:541-543. [PMID: 29966475 DOI: 10.1080/10428194.2018.1482544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Andrea Kaifie
- a Institute of Occupational, Social and Environmental Medicine, Medical Faculty , RWTH Aachen University
| | - Christian Schikowsky
- a Institute of Occupational, Social and Environmental Medicine, Medical Faculty , RWTH Aachen University
| | - Theresa Vasko
- a Institute of Occupational, Social and Environmental Medicine, Medical Faculty , RWTH Aachen University
| | - Thomas Kraus
- a Institute of Occupational, Social and Environmental Medicine, Medical Faculty , RWTH Aachen University
| | - Tim Henrik Brümmendorf
- b Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation , University Hospital RWTH Aachen, Medical Faculty , Aachen , Germany
| | - Patrick Ziegler
- a Institute of Occupational, Social and Environmental Medicine, Medical Faculty , RWTH Aachen University
| |
Collapse
|
5
|
Griggio V, Mandili G, Vitale C, Capello M, Macor P, Serra S, Castella B, Peola S, Foglietta M, Drandi D, Omedé P, Sblattero D, Cappello P, Chiarle R, Deaglio S, Boccadoro M, Novelli F, Massaia M, Coscia M. Humoral immune responses toward tumor-derived antigens in previously untreated patients with chronic lymphocytic leukemia. Oncotarget 2018; 8:3274-3288. [PMID: 27906678 PMCID: PMC5356881 DOI: 10.18632/oncotarget.13712] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 11/22/2016] [Indexed: 11/25/2022] Open
Abstract
In chronic lymphocytic leukemia (CLL) the occurrence and the impact of antibody responses toward tumor-derived antigens are largely unexplored. Our serological proteomic data show that antibodies toward 47 identified antigens are detectable in 29 out of 35 patients (83%) with untreated CLL. The glycolytic enzyme alpha-enolase (ENO1) is the most frequently recognized antigen (i.e. 54% of CLL sera). We show that ENO1 is upregulated in the proliferating B-cell fraction of CLL lymph nodes. In CLL cells of the peripheral blood, ENO1 is exclusively expressed at the intracellular level, whereas it is exposed on the surface of apoptotic leukemic cells. From the clinical standpoint, patients with progressive CLL show a higher number of antigen recognitions compared to patients with stable disease. Consistently, the anti-ENO1 antibodies are prevalent in sera from patients with progressive disease and their presence is predictive of a shorter time to first treatment. This clinical inefficacy associates with the inability of patients’ sera to trigger complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity against leukemic cells. Together, these results indicate that antibody responses toward tumor-derived antigens are frequently detectable in sera from patients with CLL, but they are expression of a disrupted immune system and unable to hamper disease progression.
Collapse
Affiliation(s)
- Valentina Griggio
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Giorgia Mandili
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Candida Vitale
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Michela Capello
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Paolo Macor
- Department of Life Sciences - University of Trieste, Trieste, Italy
| | - Sara Serra
- Department of Medical Sciences, University of Torino and Immunogenetics Unit - Human Genetics Foundation (HuGeF), Torino, Italy
| | - Barbara Castella
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Silvia Peola
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Myriam Foglietta
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Daniela Drandi
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Paola Omedé
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | | | - Paola Cappello
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Molecular Biotechnology Center, Torino, Italy
| | - Roberto Chiarle
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Pathology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Silvia Deaglio
- Department of Medical Sciences, University of Torino and Immunogenetics Unit - Human Genetics Foundation (HuGeF), Torino, Italy
| | - Mario Boccadoro
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Francesco Novelli
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Molecular Biotechnology Center, Torino, Italy.,Service of Immunogenetics and Transplantation, AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Massimo Massaia
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies (CeRMS), AOU Città della Salute e della Scienza di Torino, Torino, Italy
| | - Marta Coscia
- Division of Hematology, University of Torino, AOU Città della Salute e della Scienza di Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| |
Collapse
|
6
|
Rigoni M, Riganti C, Vitale C, Griggio V, Campia I, Robino M, Foglietta M, Castella B, Sciancalepore P, Buondonno I, Drandi D, Ladetto M, Boccadoro M, Massaia M, Coscia M. Simvastatin and downstream inhibitors circumvent constitutive and stromal cell-induced resistance to doxorubicin in IGHV unmutated CLL cells. Oncotarget 2016; 6:29833-46. [PMID: 26284584 PMCID: PMC4745766 DOI: 10.18632/oncotarget.4006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 05/15/2015] [Indexed: 01/31/2023] Open
Abstract
The immunoglobulin heavy-chain variable region (IGHV) mutational status is a strong determinant of remission duration in chronic lymphocytic leukemia (CLL). The aim of this work was to compare the multidrug resistance (MDR) signature of IGHV mutated and unmutated CLL cells, identifying biochemical and molecular targets potentially amenable to therapeutic intervention. We found that the mevalonate pathway-dependent Ras/ERK1–2 and RhoA/RhoA kinase signaling cascades, and the downstream HIF-1α/P-glycoprotein axis were more active in IGHV unmutated than in mutated cells, leading to a constitutive protection from doxorubicin-induced cytotoxicity. The constitutive MDR phenotype of IGHV unmutated cells was partially dependent on B cell receptor signaling, as shown by the inhibitory effect exerted by ibrutinib. Stromal cells further protected IGHV unmutated cells from doxorubicin by upregulating Ras/ERK1–2, RhoA/RhoA kinase, Akt, HIF-1α and P-glycoprotein activities. Mevalonate pathway inhibition with simvastatin abrogated these signaling pathways and reversed the resistance of IGHV unmutated cells to doxorubicin, also counteracting the protective effect exerted by stromal cells. Similar results were obtained via the targeted inhibition of the downstream molecules ERK1–2, RhoA kinase and HIF-1α. Therefore, targeting the mevalonate pathway and its downstream signaling cascades is a promising strategy to circumvent the MDR signature of IGHV unmutated CLL cells.
Collapse
Affiliation(s)
- Micol Rigoni
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| | - Chiara Riganti
- Department of Oncology, University of Torino, Torino, Italy
| | - Candida Vitale
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| | - Valentina Griggio
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| | - Ivana Campia
- Department of Oncology, University of Torino, Torino, Italy
| | - Marta Robino
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy
| | - Myriam Foglietta
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| | - Barbara Castella
- Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| | - Patrizia Sciancalepore
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| | | | - Daniela Drandi
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy
| | - Marco Ladetto
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy
| | - Mario Boccadoro
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy
| | - Massimo Massaia
- Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy.,S.C. Ematologia e Terapie Cellulari, Azienda Ospedaliera Ordine Mauriziano di Torino, Torino, Italy
| | - Marta Coscia
- Division of Hematology, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, University of Torino, Torino, Italy.,Center for Experimental Research and Medical Studies, Azienda Ospedaliero Universitaria Città della Salute e della Scienza di Torino, Torino, Italy
| |
Collapse
|
7
|
Xu X, Qu K, Pang Q, Wang Z, Zhou Y, Liu C. Association between telomere length and survival in cancer patients: a meta-analysis and review of literature. Front Med 2016; 10:191-203. [PMID: 27185042 DOI: 10.1007/s11684-016-0450-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 04/07/2016] [Indexed: 12/15/2022]
Abstract
The relationship between telomere length and cancer survival has been widely studied. To gain a deeper insight, we reviewed the published studies. A total of 29 studies evaluated telomere length in the peripheral blood; 22 studies evaluated telomere length in the tumor tissue. First, in the peripheral blood studies, for solid tumor patients with shortened telomere length, the combined hazard ratios (HRs) for mortality and tumor progression were 1.21 (95%CI, 1.10-1.32) and 1.71 (95%CI, 1.37-2.13), respectively. Meanwhile, in hematology malignancy, the combined HRs for mortality and tumor progression were 2.83 (95%CI, 2.14-3.74) and 2.65 (95%CI, 2.18-3.22), respectively. Second, in the studies that use tumor tissue, for patients with shortened telomeres, the combined HRs for mortality and tumor progression were 1.26 (95%CI, 0.95-1.66) and 1.65 (95%CI, 1.26-2.15), respectively. In the studies that calculate the telomere length ratios of tumor tissue to adjacent normal mucosa, for patients with lower telomere length ratios, the combined HRs were 0.66 (95%CI, 0.53-0.83) and 0.74 (95%CI, 0.41-1.32) for mortality and tumor progression, respectively. In conclusion, shortened telomere in peripheral blood and tumor tissue might indicate poor survival for cancer patients. However, by calculating the telomere length ratios of tumor tissue to adjacent normal mucosa, the lower ratio might indicate better survival.
Collapse
Affiliation(s)
- Xinsen Xu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Kai Qu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Qing Pang
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Zhixin Wang
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Yanyan Zhou
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, China
| | - Chang Liu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University, Xi'an, 710061, China.
| |
Collapse
|
8
|
Medves S, Auchter M, Chambeau L, Gazzo S, Poncet D, Grangier B, Verney A, Moussay E, Ammerlaan W, Brisou G, Morjani H, Géli V, Palissot V, Berchem G, Salles G, Wenner T. A high rate of telomeric sister chromatid exchange occurs in chronic lymphocytic leukaemia B-cells. Br J Haematol 2016; 174:57-70. [PMID: 26970083 DOI: 10.1111/bjh.13995] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 12/25/2015] [Indexed: 01/30/2023]
Abstract
Cancer cells protect their telomere ends from erosion through reactivation of telomerase or by using the Alternative Lengthening of Telomere (ALT) mechanism that depends on homologous recombination. Chronic lymphocytic leukaemia (CLL) B cells are characterized by almost no telomerase activity, shelterin deregulation and telomere fusions. To characterize telomeric maintenance mechanisms in B-CLL patients, we measured their telomere length, telomerase expression and the main hallmarks of the ALT activity i.e. C-circle concentration, an extra-chromosomal telomere repeat (ECTR), and the level of telomeric sister chromatid exchange (T-SCE) rate. Patients showed relative homogenous telomere length although almost no TERT transcript and nearly no C-circle were evidenced. Nevertheless, compared with normal B cells, B-CLL cells showed an increase in T-SCE rate that was correlated with a strong down-regulation of the topoisomerase III alpha (TOP3A) expression, involved in the dissolution of Holliday Junctions (HJ), together with an increased expression of SLX1A, SLX4, MUS81 and GEN1, involved in the resolution of HJ. Altogether, our results suggest that the telomere maintenance mechanism of B-CLL cells do not preferentially use telomerase or ALT. Rather, the rupture of the dissolvasome/resolvasome balance may increase telomere shuffling that could homogenize telomere length, slowing telomere erosion in this disease.
Collapse
Affiliation(s)
- Sandrine Medves
- Laboratory of Experimental Cancer Research, LIH, Luxembourg, Luxembourg
| | - Morgan Auchter
- Cancer Research Centre Marseille CRCM, U1068 Inserm, UMR7258 CNRS, Aix-Marseille University, Institut Paoli-Calmettes, Ligue Nationale contre le Cancer équipe labellisée, Marseille, France
| | - Laetitia Chambeau
- Laboratory of Experimental Cancer Research, LIH, Luxembourg, Luxembourg
| | - Sophie Gazzo
- Equipe Proliférations B Indolentes, Faculté de Médecine Lyon Sud, UMR CNRS 5239, Oullins Cedex, France
| | - Delphine Poncet
- Biochemistry Department, Transfer and Molecular Oncology Unit, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon, France.,Faculté de Médecine, UCBL Lyon 1, Oullins cedex 12, France
| | - Blandine Grangier
- Biochemistry Department, Transfer and Molecular Oncology Unit, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon, France.,Faculté de Médecine, UCBL Lyon 1, Oullins cedex 12, France
| | - Aurélie Verney
- Equipe Proliférations B Indolentes, Faculté de Médecine Lyon Sud, UMR CNRS 5239, Oullins Cedex, France
| | - Etienne Moussay
- Laboratory of Experimental Cancer Research, LIH, Luxembourg, Luxembourg
| | - Wim Ammerlaan
- Core Facility Flow Cytometry, Centre de Recherche Public de la Santé (CRP-Santé), Luxembourg, Luxembourg
| | - Gabriel Brisou
- Equipe Proliférations B Indolentes, Faculté de Médecine Lyon Sud, UMR CNRS 5239, Oullins Cedex, France
| | - Hamid Morjani
- MEDyC, Unité CNRS UMR7369, UFR de Pharmacie, Reims, France
| | - Vincent Géli
- Cancer Research Centre Marseille CRCM, U1068 Inserm, UMR7258 CNRS, Aix-Marseille University, Institut Paoli-Calmettes, Ligue Nationale contre le Cancer équipe labellisée, Marseille, France
| | - Valérie Palissot
- Laboratory of Experimental Cancer Research, LIH, Luxembourg, Luxembourg
| | - Guy Berchem
- Laboratory of Experimental Cancer Research, LIH, Luxembourg, Luxembourg
| | - Gilles Salles
- Equipe Proliférations B Indolentes, Faculté de Médecine Lyon Sud, UMR CNRS 5239, Oullins Cedex, France
| | - Thomas Wenner
- Laboratory of Experimental Cancer Research, LIH, Luxembourg, Luxembourg.,Equipe Proliférations B Indolentes, Faculté de Médecine Lyon Sud, UMR CNRS 5239, Oullins Cedex, France
| |
Collapse
|
9
|
Telomere shortening associated with increased genomic complexity in chronic lymphocytic leukemia. Tumour Biol 2015; 36:8317-24. [DOI: 10.1007/s13277-015-3556-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/11/2015] [Indexed: 01/08/2023] Open
|
10
|
Lin TT, Norris K, Heppel NH, Pratt G, Allan JM, Allsup DJ, Bailey J, Cawkwell L, Hills R, Grimstead JW, Jones RE, Britt-Compton B, Fegan C, Baird DM, Pepper C. Telomere dysfunction accurately predicts clinical outcome in chronic lymphocytic leukaemia, even in patients with early stage disease. Br J Haematol 2014; 167:214-23. [PMID: 24990087 DOI: 10.1111/bjh.13023] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/03/2014] [Indexed: 12/18/2022]
Abstract
Defining the prognosis of individual cancer sufferers remains a significant clinical challenge. Here we assessed the ability of high-resolution single telomere length analysis (STELA), combined with an experimentally derived definition of telomere dysfunction, to predict the clinical outcome of patients with chronic lymphocytic leukaemia (CLL). We defined the upper telomere length threshold at which telomere fusions occur and then used the mean of the telomere 'fusogenic' range as a prognostic tool. Patients with telomeres within the fusogenic range had a significantly shorter overall survival (P < 0·0001; Hazard ratio [HR] = 13·2, 95% confidence interval [CI] = 11·6-106·4) and this was preserved in early-stage disease patients (P < 0·0001, HR=19·3, 95% CI = 17·8-802·5). Indeed, our assay allowed the accurate stratification of Binet stage A patients into those with indolent disease (91% survival at 10 years) and those with poor prognosis (13% survival at 10 years). Furthermore, patients with telomeres above the fusogenic mean showed superior prognosis regardless of their IGHV mutation status or cytogenetic risk group. In keeping with this finding, telomere dysfunction was the dominant variable in multivariate analysis. Taken together, this study provides compelling evidence for the use of high-resolution telomere length analysis coupled with a definition of telomere dysfunction in the prognostic assessment of CLL.
Collapse
Affiliation(s)
- Thet Thet Lin
- Cardiff CLL Research Group, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Cardiff, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Hoxha M, Fabris S, Agnelli L, Bollati V, Cutrona G, Matis S, Recchia AG, Gentile M, Cortelezzi A, Morabito F, Bertazzi PA, Ferrarini M, Neri A. Relevance of telomere/telomerase system impairment in early stage chronic lymphocytic leukemia. Genes Chromosomes Cancer 2014; 53:612-21. [PMID: 24706380 DOI: 10.1002/gcc.22171] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/18/2014] [Indexed: 01/10/2023] Open
Abstract
Several studies have proposed telomere length and telomerase activity as prognostic factors in chronic lymphocytic leukemia (CLL), whereas information addressing the role of telomere-associated genes is limited. We measured relative telomere length (RTL) and TERT expression levels in purified peripheral CD19(+) B-cells from seven healthy donors and 77 untreated CLLs in early stage disease (Binet A). Data were correlated with the major biological and cytogenetic markers, global DNA methylation (Alu and LINE-1), and clinical outcome. The expression profiles of telomere-associated genes were also investigated. RTL was decreased in CLLs as compared with controls (P < 0.001); within CLL, a progressive and significant RTL shortening was observed in patients from 13q- through +12, 11q-, and 17p- alterations; short telomeres were significantly associated with unmutated IGHV configuration and global DNA hypomethylation. Decreased RTL was associated with a shorter time to first treatment. A significant upregulation of POT1, TRF1, RAP1, MRE11A, RAD50, and RPA1 transcript levels was observed in CLLs compared with controls. Our study suggests that impairment of telomere/telomerase system represents an early event in CLL pathogenesis. Moreover, the correlation between telomere shortening and global DNA hypomethylation supports the involvement of DNA hypomethylation to increase chromosome instability. © 2014 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Mirjam Hoxha
- Department of Clinical Sciences and Community Health, Center of Molecular and Genetic Epidemiology, University of Milan, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Mansouri L, Grabowski P, Degerman S, Svenson U, Gunnarsson R, Cahill N, Smedby KE, Geisler C, Juliusson G, Roos G, Rosenquist R. Short telomere length is associated with NOTCH1/SF3B1/TP53 aberrations and poor outcome in newly diagnosed chronic lymphocytic leukemia patients. Am J Hematol 2013; 88:647-51. [PMID: 23620080 DOI: 10.1002/ajh.23466] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/28/2013] [Accepted: 04/18/2013] [Indexed: 12/21/2022]
Abstract
Most previous studies on telomere length (TL) in chronic lymphocytic leukemia (CLL) are based on referral cohorts including a high proportion of aggressive cases. Here, the impact of TL was analyzed in a population-based cohort of newly diagnosed CLL (n = 265) and in relation to other prognostic markers. Short telomeres were particularly associated with high-risk genetic markers, such as NOTCH1, SF3B1, or TP53 aberrations, and predicted a short time to treatment (TTT) and overall survival (OS) (both P < 0.0001). TL was an independent prognostic factor and subdivided patients with otherwise good-prognostic features (e.g., mutated IGHV genes, favorable cytogenetics) into subgroups with different outcome. Furthermore, in follow-up samples (n = 119) taken 5-8 years after diagnosis, TL correlated well with TL at diagnosis and remained unaffected by treatment. Altogether, these novel data indicate that short TL already at diagnosis is associated with poor outcome in CLL and that TL can be measured at later stages of the disease.
Collapse
Affiliation(s)
- Larry Mansouri
- Department of Immunology; Genetics; and Pathology; Rudbeck Laboratory; Uppsala University; Uppsala; Sweden
| | - Pawel Grabowski
- Department of Medical Biosciences; Umeå University; Umeå; Sweden
| | - Sofie Degerman
- Department of Medical Biosciences; Umeå University; Umeå; Sweden
| | - Ulrika Svenson
- Department of Medical Biosciences; Umeå University; Umeå; Sweden
| | - Rebeqa Gunnarsson
- Department of Immunology; Genetics; and Pathology; Rudbeck Laboratory; Uppsala University; Uppsala; Sweden
| | - Nicola Cahill
- Department of Immunology; Genetics; and Pathology; Rudbeck Laboratory; Uppsala University; Uppsala; Sweden
| | - Karin Ekström Smedby
- Department of Medicine; Clinical Epidemiology Unit; Karolinska Institutet; Stockholm; Sweden
| | | | - Gunnar Juliusson
- Department of Laboratory Medicine; Stem Cell Center; Hematology and Transplantation; Lund University; Lund; Sweden
| | - Göran Roos
- Department of Medical Biosciences; Umeå University; Umeå; Sweden
| | - Richard Rosenquist
- Department of Immunology; Genetics; and Pathology; Rudbeck Laboratory; Uppsala University; Uppsala; Sweden
| |
Collapse
|
13
|
Shawi M, Chu TW, Martinez-Marignac V, Yu Y, Gryaznov SM, Johnston JB, Lees-Miller SP, Assouline SE, Autexier C, Aloyz R. Telomerase contributes to fludarabine resistance in primary human leukemic lymphocytes. PLoS One 2013; 8:e70428. [PMID: 23922990 PMCID: PMC3726637 DOI: 10.1371/journal.pone.0070428] [Citation(s) in RCA: 15] [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: 03/13/2013] [Accepted: 06/17/2013] [Indexed: 12/17/2022] Open
Abstract
We report that Imetelstat, a telomerase inhibitor that binds to the RNA component of telomerase (hTR), can sensitize primary CLL lymphocytes to fludarabine in vitro. This effect was observed in lymphocytes from clinically resistant cases and with cytogenetic abnormalities associated with bad prognosis. Imetelstat mediated-sensitization to fludarabine was not associated with telomerase activity, but with the basal expression of Ku80. Since both Imetelstat and Ku80 bind hTR, we assessed 1) if Ku80 and Imetelstat alter each other's binding to hTR in vitro and 2) the effect of an oligonucleotide complementary to the Ku binding site in hTR (Ku oligo) on the survival of primary CLL lymphocytes exposed to fludarabine. We show that Imetelstat interferes with the binding of Ku70/80 (Ku) to hTR and that the Ku oligo can sensitize CLL lymphocytes to FLU. Our results suggest that Ku binding to hTR may contribute to fludarabine resistance in CLL lmphocytes. This is the first report highlighting the potentially broad effectiveness of Imetelstat in CLL, and the potential biological and clinical implications of a functional interaction between Ku and hTR in primary human cancer cells.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Catalytic Domain/drug effects
- Chromosome Deletion
- Chromosomes, Human, Pair 11
- Chromosomes, Human, Pair 17
- DNA Helicases/genetics
- DNA Helicases/metabolism
- Drug Resistance, Neoplasm/genetics
- Enzyme Activation
- Gene Expression Regulation, Leukemic/drug effects
- Histones/metabolism
- Humans
- Indoles/pharmacology
- Ku Autoantigen
- Leukemia, Lymphoid/drug therapy
- Leukemia, Lymphoid/genetics
- Leukemia, Lymphoid/metabolism
- Middle Aged
- Niacinamide/analogs & derivatives
- Niacinamide/pharmacology
- Oligonucleotides
- Phosphorylation
- Protein Binding/drug effects
- Telomerase/chemistry
- Telomerase/genetics
- Telomerase/metabolism
- Vidarabine/analogs & derivatives
- Vidarabine/pharmacology
- Vidarabine/therapeutic use
Collapse
Affiliation(s)
- May Shawi
- Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
- Bloomfield Centre for Research in Ageing, Jewish General Hospital, Montreal, Quebec, Canada
| | - Tsz Wai Chu
- Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
- Bloomfield Centre for Research in Ageing, Jewish General Hospital, Montreal, Quebec, Canada
| | - Veronica Martinez-Marignac
- Lady Davis Institute for Medical Research & Cancer Segal Center, Jewish General Hospital, Montreal, Quebec, Canada
| | - Y. Yu
- University of Calgary, Department of Biochemistry and Molecular Biology, Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
| | | | - James B. Johnston
- Manitoba Institute of Cell Biology, Cancer Care Manitoba, Winnipeg, Manitoba, Canada
| | - Susan P. Lees-Miller
- University of Calgary, Department of Biochemistry and Molecular Biology, Southern Alberta Cancer Research Institute, Calgary, Alberta, Canada
| | - Sarit E. Assouline
- Oncology Department, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research & Cancer Segal Center, Jewish General Hospital, Montreal, Quebec, Canada
| | - Chantal Autexier
- Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
- Bloomfield Centre for Research in Ageing, Jewish General Hospital, Montreal, Quebec, Canada
| | - Raquel Aloyz
- Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
- Oncology Department, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research & Cancer Segal Center, Jewish General Hospital, Montreal, Quebec, Canada
- * E-mail:
| |
Collapse
|
14
|
Telomere shortening in Ph-negative chronic myeloproliferative neoplasms: A biological marker of polycythemia vera and myelofibrosis, regardless of hydroxycarbamide therapy. Exp Hematol 2013; 41:627-34. [DOI: 10.1016/j.exphem.2013.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Revised: 03/17/2013] [Accepted: 03/19/2013] [Indexed: 02/08/2023]
|
15
|
Lobetti-Bodoni C, Bertoni F, Stussi G, Cavalli F, Zucca E. The changing paradigm of chronic lymphocytic leukemia management. Eur J Intern Med 2013; 24:401-10. [PMID: 23583413 DOI: 10.1016/j.ejim.2013.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 03/14/2013] [Accepted: 03/15/2013] [Indexed: 10/27/2022]
Abstract
B cell-chronic lymphocytic leukemia (CLL), the commonest adult leukemia in western world, is today most often diagnosed at early-stage, following the accidental detection of lymphocytosis during a routine blood analysis. Moreover, the expectations of CLL patients have dramatically changed in the past decade and for the first time a significant overall survival improvement has been demonstrated in the disease--at least in the younger and fit patients--with the use of the FCR regimen, which combines rituximab fludarabine and cyclophosphamide. New drugs and new regimens are currently being developed for the relapsed patients and for those too old or too frail to receive aggressive treatments. Some of these promising compounds will likely be part of the future front-line treatments. Additionally, the increasing knowledge on the molecular features that predict the clinical outcome may soon result in a molecular classification of the disease. These acquisitions are producing a migration from palliative care to a curative and individually-tailored approach. In this review we tried to summarize the advances achieved in the past decade and help the specialists in internal medicine and the general practitioners to understand the completely changed scenario in which the disease should nowadays be managed.
Collapse
Affiliation(s)
- Chiara Lobetti-Bodoni
- Oncology Institute of Southern Switzerland (IOSI), Ospedale San Giovanni, Bellinzona, Switzerland
| | | | | | | | | |
Collapse
|
16
|
Martinelli S, Kanduri M, Maffei R, Fiorcari S, Bulgarelli J, Marasca R, Rosenquist R. ANGPT2 promoter methylation is strongly associated with gene expression and prognosis in chronic lymphocytic leukemia. Epigenetics 2013; 8:720-9. [PMID: 23803577 DOI: 10.4161/epi.24947] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Increasing evidence suggests a key role for angiopoietin-2 (ANGPT2) in influencing the aggressiveness of chronic lymphocytic leukemia (CLL). In the presence of vascular endothelial growth factor (VEGF), ANGPT2 causes vessel destabilization leading to neoangiogenesis. Accordingly, high expression levels of ANGPT2 and high degree of angiogenesis have consistently been associated with poor prognosis in CLL; however, the molecular mechanisms behind the variability in ANGPT2 expression are still to be discovered. Here, for the first time, we investigated the DNA methylation status of the ANGPT2 promoter in a large CLL cohort (n = 88) using pyrosequencing and correlated methylation data with ANGPT2 expression levels, prognostic factors and outcome. Importantly, methylation levels of the ANGPT2 gene correlated inversely with its mRNA expression levels (p<0.001). Moreover, low ANGPT2 methylation status was highly associated with adverse prognostic markers, shorter time to first treatment and overall survival. Finally, treatment with methyl inhibitors induced re-expression of ANGPT2 in two B-cell lymphoma cell lines, underscoring the importance of DNA methylation in regulating transcriptional silencing of this gene. In conclusion, we believe that the known variability in ANGPT2 expression among CLL patients could be explained by differential promoter DNA methylation and that low methylation levels of the ANGPT2 promoter have an adverse prognostic impact in CLL.
Collapse
Affiliation(s)
- Silvia Martinelli
- Hematology Unit, Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | | | | | | | | | | | |
Collapse
|
17
|
Dysfunctional Vγ9Vδ2 T cells are negative prognosticators and markers of dysregulated mevalonate pathway activity in chronic lymphocytic leukemia cells. Blood 2012; 120:3271-9. [DOI: 10.1182/blood-2012-03-417519] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Abstract
The role of Vγ9Vδ2 T cells in chronic lymphocytic leukemia (CLL) is unexplored, although these cells have a natural inclination to react against B-cell malignancies. Proliferation induced by zoledronic acid was used as a surrogate of γδ TCR-dependent stimulation to functionally interrogate Vγ9Vδ2 T cells in 106 untreated CLL patients. This assay permitted the identification of responder and low-responder (LR) patients. The LR status was associated with greater baseline counts of Vγ9Vδ2 T cells and to the expansion of the effector memory and terminally differentiated effector memory subsets. The tumor immunoglobulin heavy chain variable region was more frequently unmutated in CLL cells of LR patients, and the mevalonate pathway, which generates Vγ9Vδ2 TCR ligands, was more active in unmutated CLL cells. In addition, greater numbers of circulating regulatory T cells were detected in LR patients. In multivariate analysis, the LR condition was an independent predictor of shorter time-to-first treatment. Accordingly, the time-to-first treatment was significantly shorter in patients with greater baseline numbers of total Vγ9Vδ2 T cells and effector memory and terminally differentiated effector memory subpopulations. These results unveil a clinically relevant in vivo relationship between the mevalonate pathway activity of CLL cells and dys-functional Vγ9Vδ2 T cells.
Collapse
|
18
|
Abstract
Observations in human tumours, as well as mouse models, have indicated that telomere dysfunction may be a key event driving genomic instability and disease progression in many solid tumour types. In this scenario, telomere shortening ultimately results in telomere dysfunction, fusion and genomic instability, creating the large-scale rearrangements that are characteristic of these tumours. It is now becoming apparent that this paradigm may also apply to haematological malignancies; indeed these conditions have provided some of the most convincing evidence of telomere dysfunction in any malignancy. Telomere length has been shown in several malignancies to provide clinically useful prognostic information, implicating telomere dysfunction in disease progression. In these malignancies extreme telomere shortening, telomere dysfunction and fusion have all been documented and correlate with the emergence of increased genomic complexity. Telomeres may therefore represent both a clinically useful prognostic tool and a potential target for therapeutic intervention.
Collapse
Affiliation(s)
- Ceri H Jones
- Department of Haematology,School of Medicine, Cardiff University, Cardiff, UK
| | | | | |
Collapse
|
19
|
Rampazzo E, Bonaldi L, Trentin L, Visco C, Keppel S, Giunco S, Frezzato F, Facco M, Novella E, Giaretta I, Del Bianco P, Semenzato G, De Rossi A. Telomere length and telomerase levels delineate subgroups of B-cell chronic lymphocytic leukemia with different biological characteristics and clinical outcomes. Haematologica 2011; 97:56-63. [PMID: 21933855 DOI: 10.3324/haematol.2011.049874] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND B-cell chronic lymphocytic leukemia is a clinically heterogeneous disease; some patients rapidly progress and die within a few years of diagnosis, whereas others have a long life expectancy with minimal or no treatment. Telomere length and telomerase levels have been proposed as prognostic factors; however, very few cases have been characterized for both parameters and no study has analyzed the prognostic value of the telomere/telomerase profile. DESIGN AND METHODS One hundred and seventy-three cases of chronic lymphocytic leukemia were characterized for telomere lengths and telomerase levels by real-time polymerase chain reaction. Data were correlated with established prognostic markers, IGVH mutational status and chromosomal aberrations, and clinical outcome. RESULTS Telomere lengths were inversely correlated with telomerase levels (r(s) = -0.213; P = 0.012), and most of the cases of chronic lymphocytic leukemia with high levels (above median) of telomerase had short (below median) telomeres (P = 0.0001). Telomerase levels were higher and telomeres were shorter in unmutated IGVH cases than in mutated IGVH ones (P<0.0001). Chronic lymphocytic leukemias with 11q, 17p deletion or 12 trisomy had significantly higher levels of telomerase and shorter telomeres than those with no chromosomal aberration or the sole 13q deletion (P < 0.001). Telomere length/telomerase level profiles identified subgroups of patients with different clinical outcomes (P < 0.0001), even within the subsets of chronic lymphocytic leukemia defined by IGVH mutational status or chromosomal aberrations. Short telomere/high telomerase profile was independently associated with more rapid disease progression. CONCLUSIONS Comprehensive analyses of telomeres, telomerase, chromosomal aberrations, and IGVH mutational status delineate groups of chronic lymphocytic leukemias with distinct biological characteristics and clinical outcomes. The telomere/telomerase profile may be particularly useful in refining the prognosis of chronic lymphocytic leukemia patients with mutated IGVH and no high-risk chromosomal aberrations.
Collapse
Affiliation(s)
- Enrica Rampazzo
- Department of Oncology and Surgical Sciences, Oncology Section, University of Padova,Padova, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Spanoudakis E, Bazdiara I, Pantelidou D, Kotsianidis I, Papadopoulos V, Margaritis D, Xanthopoulidis G, Moustakidis E, Mantzourani S, Bourikas G, Tsatalas C. Dynamics of telomere's length and telomerase activity in Philadelphia chromosome negative myeloproliferative neoplasms. Leuk Res 2011; 35:459-64. [DOI: 10.1016/j.leukres.2010.07.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/30/2010] [Accepted: 07/30/2010] [Indexed: 11/25/2022]
|
21
|
Pepper C, Baird DM. Shortened telomeres: a driving force behind leukemia? Future Oncol 2011; 6:1681-6. [PMID: 21142655 DOI: 10.2217/fon.10.135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
|
22
|
IGHV unmutated CLL B cells are more prone to spontaneous apoptosis and subject to environmental prosurvival signals than mutated CLL B cells. Leukemia 2011; 25:828-37. [DOI: 10.1038/leu.2011.12] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
23
|
Telomeric damage in early stage of chronic lymphocytic leukemia correlates with shelterin dysregulation. Blood 2011; 118:1316-22. [PMID: 21355086 DOI: 10.1182/blood-2010-07-295774] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cells of B-cell chronic lymphocytic leukemia (B-CLL) are characterized by short telomeres despite a low proliferative index. Because telomere length has been reported to be a valuable prognosis criteria, there is a great interest in a deep understanding of the origin and consequences of telomere dysfunction in this pathology. Cases of chromosome fusion involving extremely short telomeres have been reported at advanced stage. In the present study, we address the question of the existence of early telomere dysfunction during the B-CLL time course. In a series restricted to 23 newly diagnosed Binet stage A CLL patients compared with 12 healthy donors, we found a significant increase in recruitment of DNA-damage factors to telomeres showing telomere dysfunction in the early stage of the disease. Remarkably, the presence of dysfunctional telomeres did not correlate with telomere shortening or chromatin marks deregulation but with a down-regulation of 2 shelterin genes: ACD (coding for TPP1; P = .0464) and TINF2 (coding for TIN2; P = .0177). We propose that telomeric deprotection in the early step of CLL is not merely the consequence of telomere shortening but also of shelterin alteration.
Collapse
|
24
|
Lobetti-Bodoni C, Bernocco E, Genuardi E, Boccadoro M, Ladetto M. Telomeres and telomerase in normal and malignant B-cells. Hematol Oncol 2011; 28:157-67. [PMID: 20213664 DOI: 10.1002/hon.937] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The telomeric checkpoint is emerging as a critical sensor of cellular damage, playing a major role in human aging and cancer development. In the meantime, telomere biology is rapidly evolving from a basic discipline to a translational branch, capable of providing major hints for biomarker development, risk assessment and targeted treatment of cancer. These advances have a number of implications in the biology of lymphoid tumours. Moreover, there is considerable interest in the potential role of telomeric dysfunction in the wide array of immunological abnormalities, grouped under the definition of 'immunosenescence'. This review will summarize the impact of recent advances in telomere biology on the physiology and pathology of the B lymphocyte, with special interest in immunosenescence and lymphomagenesis.
Collapse
Affiliation(s)
- Chiara Lobetti-Bodoni
- Department of Experimental Oncology, Division of Hematology, University of Torino, Italy
| | | | | | | | | |
Collapse
|
25
|
Sellmann L, de Beer D, Bartels M, Opalka B, Nückel H, Dührsen U, Dürig J, Seifert M, Siemer D, Küppers R, Baerlocher GM, Röth A. Telomeres and prognosis in patients with chronic lymphocytic leukaemia. Int J Hematol 2011; 93:74-82. [PMID: 21203871 DOI: 10.1007/s12185-010-0750-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 11/03/2010] [Accepted: 12/13/2010] [Indexed: 11/27/2022]
Abstract
In the present study, telomere length, telomerase activity, the mutation load of immunoglobulin variable heavy chain (IGHV) genes, and established prognostic factors were investigated in 78 patients with chronic lymphocytic leukaemia (CLL) to determine the impact of telomere biology on the pathogenesis of CLL. Telomere length was measured by an automated multi-colour flow-FISH, and an age-independent delta telomere length (ΔTL) was calculated. CLL with unmutated IGHV genes was associated with shorter telomeres (p = 0.002). Furthermore, we observed a linear correlation between the frequency of IGHV gene mutations and elongation of telomeres (r = 0.509, p < 0.001). With respect to prognosis, a threshold ΔTL of -4.2 kb was the best predictor for progression-free and overall survival. ΔTL was not significantly altered over time or with therapy. The correlation between the mutational load in IGHV genes and the ΔTL in CLL might reflect the initial telomere length of the putative cell of origin (pre- versus post-germinal center B cells). In conclusion, the ΔTL is a reliable prognostic marker for patients with CLL. Short telomeres and high telomerase activity as occurs in some patients with CLL with a worse prognosis might be an ideal target for treatment with telomerase inhibitors.
Collapse
MESH Headings
- Disease-Free Survival
- Female
- Humans
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Variable Region/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/genetics
- Leukemia, Lymphocytic, Chronic, B-Cell/metabolism
- Leukemia, Lymphocytic, Chronic, B-Cell/mortality
- Leukemia, Lymphocytic, Chronic, B-Cell/pathology
- Leukemia, Lymphocytic, Chronic, B-Cell/therapy
- Male
- Mutation
- Retrospective Studies
- Survival Rate
- Telomere/genetics
Collapse
Affiliation(s)
- Ludger Sellmann
- Department of Haematology, University of Duisburg Essen, Essen, Germany.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Dolcetti R, De Rossi A. Telomere/telomerase interplay in virus-driven and virus-independent lymphomagenesis: pathogenic and clinical implications. Med Res Rev 2010; 32:233-53. [PMID: 20549676 DOI: 10.1002/med.20211] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Telomerase is a ribonucleoprotein complex critically involved in extending and maintaining telomeres. Unlike the majority of somatic cells, in which hTERT and telomerase activity are generally silent, normal lymphocytes show transient physiological hTERT expression and telomerase activity according to their differentiation/activation status. During lymphomagenesis, induction of persistent telomerase expression and activity may occur before or after telomere shortening, as a consequence of the different mechanisms through which transforming factors/agents may activate telomerase. Available data indicate that the timing of telomerase activation may allow the distinction of two different lymphomagenetic models: (i) an early activation of telomerase via exogenous regulators of hTERT, along with an increased lymphocyte growth and a subsequent selection of cells with increased transforming potential may characterize several virus-related lymphoid malignancies; (ii) a progressive shortening of telomeres, leading to genetic instability which favors a subsequent activation of telomerase via endogenous regulators may occur in most virus-unrelated lymphoid tumors. These models may have clinically relevant implications, particularly for the tailoring of therapeutic strategies targeting telomerase.
Collapse
Affiliation(s)
- Riccardo Dolcetti
- Cancer Bio-Immunotherapy Unit, Department of Medical Oncology, CRO-IRCCS, National Cancer Institute, Aviano, Italy.
| | | |
Collapse
|
27
|
Telomere dysfunction-induced foci arise with the onset of telomeric deletions and complex chromosomal aberrations in resistant chronic lymphocytic leukemia cells. Blood 2010; 116:239-49. [PMID: 20424183 DOI: 10.1182/blood-2009-12-257618] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In somatic cells, eroded telomeres can induce DNA double-strand break signaling, leading to a form of replicative senescence or apoptosis, both of which are barriers to tumorigenesis. However, cancer cells might display telomere dysfunctions which in conjunction with defects in DNA repair and apoptosis, enables them to circumvent these pathways. Chronic lymphocytic leukemia (CLL) cells exhibit telomere dysfunction, and a subset of these cells are resistant to DNA damage-induced apoptosis and display short telomeres. We show here that these cells exhibit significant resection of their protective telomeric 3' single-stranded overhangs and an increased number of telomere-induced foci containing gammaH2AX and 53BP1. Chromatin immunoprecipitation and immunofluorescence experiments demonstrated increased levels of telomeric Ku70 and phospho-S2056-DNA-PKcs, 2 essential components of the mammalian nonhomologous end-joining DNA repair system. Notably, these CLL cells display deletions of telomeric signals on one or 2 chromatids in parallel with 11q22 deletions, or with 13q14 deletions associated with another chromosomal aberration or with a complex karyotype. Taken together, our results indicate that a subset of CLL cells from patients with an unfavorable clinical outcome harbor a novel type of chromosomal aberration resulting from telomere dysfunction.
Collapse
|
28
|
Lopez-Guerra M, Colomer D. NF-kappaB as a therapeutic target in chronic lymphocytic leukemia. Expert Opin Ther Targets 2010; 14:275-88. [PMID: 20148715 DOI: 10.1517/14728221003598930] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
IMPORTANCE OF THE FIELD NF-kappaB includes a family of transcription factors that play a critical role in the biology of normal lymphocytes and it is aberrantly activated in chronic lymphocytic leukemia (CLL) cells. Here, we review the role of constitutive NF-kappaB activation in CLL pathogenesis and its potential as a therapeutic target for CLL treatment. AREAS COVERED IN THIS REVIEW This review highlights the different strategies reported to inhibit NF-kappaB signaling in CLL cells. They include both IkappaB kinase inhibitors and several natural compounds that act at different steps of the pathway. WHAT THE READER WILL GAIN Targeting NF-kappaB leads to apoptosis of CLL cells, corroborating the role of NF-kappaB in the survival and clonal expansion of these tumoral cells. Moreover, several studies confirmed a synergistic effect between NF-kappaB inhibitors and other antitumoral agents and that inhibition of NF-kappaB could overcome the microenvironmental protection of CLL cells. TAKE HOME MESSAGE NF-kappaB is a relevant target in CLL and inhibitors of this prosurvival pathway, alone or in combination, represent a novel therapeutic strategy for the treatment of CLL patients.
Collapse
Affiliation(s)
- Monica Lopez-Guerra
- Hematopathology Unit, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Villarroel 170, 08036 Barcelona, Spain
| | | |
Collapse
|
29
|
Angiopoietin-2 plasma dosage predicts time to first treatment and overall survival in chronic lymphocytic leukemia. Blood 2010; 116:584-92. [PMID: 20382847 DOI: 10.1182/blood-2009-11-252494] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The clinical relevance of angiopoietin-2 (Ang2) in chronic lymphocytic leukemia (CLL) was previously suggested by the association between high Ang2, and shorter progression-free survival reported in small series of patients. Here, we evaluated Ang2 glycoprotein levels in plasma samples collected from a multicentric cohort of CLL patients (n = 316) using an enzyme-linked immunosorbent assay method, and we investigated its prognostic role in relation to time to first treatment (TTFT) and overall survival. Based on a cutoff equal to 2459 pg/mL, we divided our cohort in 2 subsets (high and low Ang2) composing 100 (31.6%) and 216 (68.4%) patients, respectively. High Ang2 was predictive of reduced TTFT (P < .001) and overall survival (P = .002). Multivariate analysis confirmed that high Ang2 was an independent prognosticator for TTFT (hazard ratio = 1.739; 95% confidence interval, 1.059-2.857; P = .029). Significant associations were found between high Ang2 and advanced Binet stages (P < .001), high beta(2)-microglobulin (P < .001), unmutated variable region of immunoglobulin heavy chain gene status (P < .001), high CD38 and zeta-chain-associated protein kinase 70 expression (P < .001 and P = .003), and intermediate/high cytogenetic risk (P = .005). Moreover, Ang2 added prognostic power to other conventional prognosticators and helped to refine prognosis among CLL subsets with both high and low vascular endothelial growth factor plasma levels. Ang2 plasma level may be a useful independent prognosticator for CLL.
Collapse
|
30
|
Del Poeta G, Del Principe MI, Maurillo L, Rossi FM, Buccisano F, Ammatuna E, Simotti C, Zucchetto A, Catalano G, Bulian P, Bruno A, Venditti A, De Fabritiis P, Gattei V, Amadori S. Spontaneous apoptosis and proliferation detected by BCL-2 and CD71 proteins are important progression indicators within ZAP-70 negative chronic lymphocytic leukemia. Leuk Lymphoma 2009; 51:95-106. [DOI: 10.3109/10428190903350421] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
31
|
Rossi D, Lobetti Bodoni C, Genuardi E, Monitillo L, Drandi D, Cerri M, Deambrogi C, Ricca I, Rocci A, Ferrero S, Bernocco E, Capello D, De Paoli L, Bergui L, Boi M, Omedè P, Massaia M, Tarella C, Passera R, Boccadoro M, Gaidano G, Ladetto M. Telomere length is an independent predictor of survival, treatment requirement and Richter's syndrome transformation in chronic lymphocytic leukemia. Leukemia 2009; 23:1062-72. [PMID: 19340005 DOI: 10.1038/leu.2008.399] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Telomere length (TL) has been associated with outcome in chronic lymphocytic leukemia (CLL). The aim of this extensive analysis carried out on 401 CLL patients was to assess TL conclusively as a prognostic biomarker. Our study included two cohorts used as learning (191 patients) and blinded validation series (210 patients). A TL cutoff of 5000 bp was chosen by receiver operating characteristic (ROC) analysis and Youden's index in the learning series. In this series, TL< or =5000 bp was independently associated to a worse outcome for both overall survival (OS; 105.5 vs 281 months, P<0.001) and treatment-free survival (TFS; 24.6 vs 73 months, P<0.001). In the blinded validation series, TL< or =5000 bp was confirmed as an independent outcome predictor for OS (79.8 vs not reached, P<0.001) and TFS (15.2 vs 130.8 months, P<0.001). Moreover, TL< or =5000 bp independently predicted the risk of Richter's syndrome (5-year risk: 18.9 vs 6.4%, P=0.016). Within CLL subsets defined by biological predictors, TL consistently identified patient subgroups harboring unfavorable prognosis. These results demonstrate that TL is a powerful independent predictor of multiple outcomes in CLL, and contributes to refine the prognostic assessment of this disease when utilized in combination with other prognostic markers. We thus believe that this prognostic biomarker has the potential for a more widespread use in CLL.
Collapse
Affiliation(s)
- D Rossi
- Division of Hematology, Department of Clinical and Experimental Medicine, Amedeo Avogadro University of Eastern Piedmont, Novara, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Svenson U, Roos G. Telomere length as a biological marker in malignancy. Biochim Biophys Acta Mol Basis Dis 2009; 1792:317-23. [PMID: 19419696 DOI: 10.1016/j.bbadis.2009.01.017] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 01/30/2009] [Accepted: 01/30/2009] [Indexed: 02/02/2023]
Abstract
Telomere maintenance is important for tumor cell growth and survival. Telomere length (TL) is determined by the balance between positive and negative factors impacting telomere homeostasis. In the last decade, TL has emerged as a promising clinical marker for risk and prognosis prediction in patients with malignant disorders. Tumor TL, as well as TL in healthy tissues such as peripheral blood, may carry valuable information for future treatment strategies. Here we discuss the present status of TL as a biological marker in cancer patients.
Collapse
Affiliation(s)
- Ulrika Svenson
- Department of Medical Biosciences, Umeå University, SE-90187 Umeå, Sweden
| | | |
Collapse
|
33
|
Van Bockstaele F, Verhasselt B, Philippé J. Prognostic markers in chronic lymphocytic leukemia: A comprehensive review. Blood Rev 2009; 23:25-47. [DOI: 10.1016/j.blre.2008.05.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
34
|
Abstract
Chronic lymphocytic leukaemia is the commonest form of leukaemia in Europe and North America, and mainly, though not exclusively, affects older individuals. It has a very variable course, with survival ranging from months to decades. Major progress has been made in identification of molecular and cellular markers that could predict disease progression in patients with chronic lymphocytic leukaemia. In particular, the mutational profile of immunoglobulin genes and some cytogenetic abnormalities are important predictors of prognosis. However, these advances have raised new questions about the biology, prognosis, and management of chronic lymphocytic leukaemia, some of which are addressed here. In particular, we discuss how better understanding of the function of the B-cell receptor, the nature of genetic lesions, and the balance between proliferation and apoptosis have affected our ability to assess prognosis and to manage chronic lymphocytic leukaemia. Available treatments generally induce remission, although nearly all patients relapse, and chronic lymphocytic leukaemia remains an incurable disease. Advances in molecular biology have enhanced our understanding of the pathophysiology of the disease and, together with development of new therapeutic agents, have made management of chronic lymphocytic leukaemia more rational and more effective than previously. Unfortunately, we know of no way that chronic lymphocytic leukaemia can be prevented. Early detection is practised widely, but seemingly makes no difference to the patient's eventual outcome.
Collapse
MESH Headings
- Antibodies, Monoclonal/therapeutic use
- Antineoplastic Agents/adverse effects
- Antineoplastic Agents/therapeutic use
- Biomarkers, Tumor/genetics
- Female
- Humans
- Leukemia, Lymphocytic, Chronic, B-Cell/diagnosis
- Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy
- Leukemia, Lymphocytic, Chronic, B-Cell/physiopathology
- Male
- Prognosis
- Randomized Controlled Trials as Topic
Collapse
Affiliation(s)
- G Dighiero
- Institut Pasteur de Montevideo, Montevideo, Uruguay
| | | |
Collapse
|
35
|
Short telomeres are associated with genetic complexity, high-risk genomic aberrations, and short survival in chronic lymphocytic leukemia. Blood 2008; 111:2246-52. [DOI: 10.1182/blood-2007-05-092759] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Telomere length is associated with mutation status of the immunoglobulin heavy chain variable (IGHV) gene and clinical course in B-cell chronic lymphocytic leukemia (B-CLL). In a B-CLL cohort of 152 patients, we analyzed telomere length, genomic aberrations, IGHV mutation status, CD38 and ZAP-70 expression to study the prognostic impact and associations among these factors. An inverse correlation existed between telomere length and IGHV homology (P < .001), CD38 (P < .001), and ZAP-70 expression (P = .01). Patients with telomere lengths below median (ie, “short telomeres”) and above median (ie, “long telomeres”) had similar incidences of genomic aberrations (74% vs 68%), 13q− (57% vs 49%), and +12q (5% vs 12%). In contrast, 13q− as a single aberration was more frequent in patients with long telomeres (51% vs 21%; P = .006), whereas 11q− (27% vs 9%; P = .014), 17p− (17% vs 0%; P < .001), and 2 or more genomic aberrations (39% vs 8%; P < .001) were more frequent in patients with short telomeres. Compared with patients with long telomeres, treatment-free survival (TFS) and overall survival (OS) was significantly shorter (P < .001 and P = .015, respectively) in the group with short telomeres, and telomere length was an independent prognostic indicator for TFS. These observations have biological and prognostic implications in B-CLL.
Collapse
|
36
|
Changes in the expression of telomere maintenance genes suggest global telomere dysfunction in B-chronic lymphocytic leukemia. Blood 2007; 111:2388-91. [PMID: 18077792 DOI: 10.1182/blood-2007-09-111245] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we explored the telomeric changes that occur in B-chronic lymphocytic leukemia (B-CLL), in which telomere length has recently been demonstrated to be a powerful prognostic marker. We carried out a transcriptomic analysis of telomerase components (hTERT and DYSKERIN), shelterin proteins (TRF1, TRF2, hRAP1, TIN2, POT1, and TPP1), and a set of multifunctional proteins involved in telomere maintenance (hEST1A, MRE11, RAD50, Ku80, and RPA1) in peripheral B cells from 42 B-CLL patients and 20 healthy donors. We found that, in B-CLL cells, the expressions of hTERT, DYSKERIN, TRF1, hRAP1, POT1, hEST1A, MRE11, RAD50, and KU80 were more than 2-fold reduced (P < .001), contrasting with the higher expression of TPP1 and RPA1 (P < .001). This differential expression pattern suggests that both telomerase down-regulation and changes in telomeric proteins composition are involved in the pathogenesis of B-CLL.
Collapse
|
37
|
Damle RN, Temburni S, Calissano C, Yancopoulos S, Banapour T, Sison C, Allen SL, Rai KR, Chiorazzi N. CD38 expression labels an activated subset within chronic lymphocytic leukemia clones enriched in proliferating B cells. Blood 2007; 110:3352-9. [PMID: 17684154 PMCID: PMC2200908 DOI: 10.1182/blood-2007-04-083832] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2007] [Accepted: 07/26/2007] [Indexed: 12/20/2022] Open
Abstract
Chronic lymphocytic leukemia (CLL) cells are thought to have diminished cell-cycling capacity, a view challenged by their phenotypic resemblance to activated human B lymphocytes. The present study addresses the cell-cycling status of CLL cells, focusing on those leukemic cells expressing CD38, a molecule involved in signaling and activation that also serves as a prognostic marker in this disease. CD38(+) and CD38(-) members of individual CLL clones were analyzed for coexpression of molecules associated with cellular activation (CD27, CD62L, and CD69), cell-cycle entry (Ki-67), signaling (ZAP-70), and protection from apoptosis (telomerase and Bcl-2). Regardless of the size of the CD38(+) fraction within a CLL clone, CD38(+) subclones are markedly enriched for expression of Ki-67, ZAP-70, human telomerase reverse transcriptase, and telomerase activity. Although the percentage of cells (approximately 2%) entering the cell cycle as defined by Ki-67 expression is small, the absolute number within a clone can be sizeable and is contained primarily within the CD38(+) fraction. Despite these activation/proliferation differences, both CD38(+) and CD38(-) fractions have similar telomere lengths, suggesting that CD38 expression is dynamic and transient. These findings may help explain why high percentages of CD38(+) cells within clones are associated with poor clinical outcome.
Collapse
Affiliation(s)
- Rajendra N Damle
- Laboratory of Experimental Immunology, The Feinstein Institute for Medical Research, North Shore-Long Island Jewish (LIJ) Health System, 350 Community Drive, Manhasset, NY 11030, USA
| | | | | | | | | | | | | | | | | |
Collapse
|