Different chromosomal breakpoints impact the level of LMO2 expression in T-ALL

Blood ◽  
2007 ◽  
Vol 110 (1) ◽  
pp. 388-392 ◽  
Author(s):  
Willem A. Dik ◽  
Bertrand Nadel ◽  
Grzegorz K. Przybylski ◽  
Vahid Asnafi ◽  
Piotr Grabarczyk ◽  
...  
Keyword(s):  
T Cell ◽  
Ex Vivo ◽  
Regulatory Element ◽  
Lymphoblastic Leukemia ◽  
Critical Role ◽  
Cell Receptor ◽  
Main Determinant ◽  
Chromosomal Breakpoints ◽  
Cell Acute Lymphoblastic Leukemia

The t(11;14)(p13;q11) is presumed to arise from an erroneous T-cell receptor delta TCRD V(D)J recombination and to result in LMO2 activation. However, the mechanisms underlying this translocation and the resulting LMO2 activation are poorly defined. We performed combined in vivo, ex vivo, and in silico analyses on 9 new t(11;14)(p13;q11)-positive T-cell acute lymphoblastic leukemia (T-ALL) as well as normal thymocytes. Our data support the involvement of 2 distinct t(11;14)(p13;q11) V(D)J-related translocation mechanisms. We provide compelling evidence that removal of a negative regulatory element from the LMO2 locus, rather than juxtaposition to the TCRD enhancer, is the main determinant for LMO2 activation in the majority of t(11;14)(p13;q11) translocations. Furthermore, the position of the LMO2 breakpoints in T-ALL in the light of the occurrence of TCRD-LMO2 translocations in normal thymocytes points to a critical role for the exact breakpoint location in determining LMO2 activation levels and the consequent pressure for T-ALL development.

scholarly journals V(D)J-mediated Translocations in Lymphoid Neoplasms: A Functional Assessment of Genomic Instability by Cryptic Sites⋆

2002 ◽  
Vol 195 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Rodrig Marculescu ◽  
Trang Le ◽  
Paul Simon ◽  
Ulrich Jaeger ◽  
Bertrand Nadel
Keyword(s):  
T Cell ◽  
Genomic Instability ◽  
Lymphoblastic Leukemia ◽  
Cell Receptor ◽  
Lymphoid Malignancies ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Normal Human ◽  
Hodgkin's Lymphomas ◽  
The Impact

Most lymphoid malignancies are initiated by specific chromosomal translocations between immunoglobulin (Ig)/T cell receptor (TCR) gene segments and cellular proto-oncogenes. In many cases, illegitimate V(D)J recombination has been proposed to be involved in the translocation process, but this has never been functionally established. Using extra-chromosomal recombination assays, we determined the ability of several proto-oncogenes to target V(D)J recombination, and assessed the impact of their recombinogenic potential on translocation rates in vivo. Our data support the involvement of 2 distinct mechanisms: translocations involving LMO2, TAL2, and TAL1 in T cell acute lymphoblastic leukemia (T-ALL), are compatible with illegitimate V(D)J recombination between a TCR locus and a proto-oncogene locus bearing a fortuitous but functional recombination site (type 1); in contrast, translocations involving BCL1 and BCL2 in B cell non-Hodgkin’s lymphomas (B-NHL), are compatible with a process in which only the IgH locus breaks are mediated by V(D)J recombination (type 2). Most importantly, we show that the t(11;14)(p13;q32) translocation involving LMO2 is present at strikingly high frequency in normal human thymus, and that the recombinogenic potential conferred by the LMO2 cryptic site is directly predictive of the in vivo level of translocation at that locus. These findings provide new insights into the regulation forces acting upon genomic instability in B and T cell tumorigenesis.

scholarly journals Rhom-2 expression does not always correlate with abnormalities on chromosome 11 at band p13 in T-cell acute lymphoblastic leukemia

Blood ◽  
1992 ◽  
Vol 80 (12) ◽  
pp. 3189-3197
Author(s):  
TJ Fitzgerald ◽  
GA Neale ◽  
SC Raimondi ◽  
RM Goorha
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Regulatory Element ◽  
Lymphoblastic Leukemia ◽  
Cell Receptor ◽  
Chromosome 11 ◽  
Sensitive Polymerase Chain Reaction ◽  
Frequent Site ◽  
Cell Acute Lymphoblastic Leukemia ◽  
T Cell Lines

A frequent site for nonrandom recombination in T-cell acute lymphoblastic leukemia (T-ALL) is chromosome 11 at p13. The molecular characterization of a (7;11)(q35;p13) translocation showed that the translocation breakpoint was 2 kb 5′ to the T-ALLbcr locus resulting in the juxtaposition of the T-cell receptor (TCR) beta gene to the rhom-2 gene locus. Northern blot analysis did not detect expression of the rhom-2 gene in the leukemic blasts of the (7;11) translocation. However, using a sensitive polymerase chain reaction (PCR)-based assay, the (7;11) translocation showed a trace expression of rhom-2 at a level of 0.01% of TCR-beta message. Because rhom-2 is considered a proto- oncogene, the significance of the trace expression of rhom-2 in the (7;11) translocation was investigated by comparing the level of rhom-2 expression in 7 additional T-ALLs, normal thymocytes, and CEM (pre-T) and HPB (mature-T) cell lines using the PCR assay. The CEM cells, normal thymocytes, and one patient, whose blasts had no cytogenetic abnormality of chromosome 11, did not express rhom-2 indicating that rhom-2 is not normally expressed in T cells. The other six T-ALLs fell into three categories: (1) two T-ALLs overexpressed rhom-2 in the presence of a translocation; (2) two T-ALLs had trace expression in the presence of a translocation; and (3) two T-ALLs had trace expression with no observable abnormalities on chromosome 11 at p13. Therefore, the data indicate that not all translocations at the T-ALLbcr locus result in overexpression of rhom-2. To account for the sharp contrast in rhom-2 expression seen in these T-ALLs, a model is proposed with a negative regulatory element in the T-ALLbcr locus that is disrupted in some of the cases leading to overexpression of rhom-2.

scholarly journals Rhom-2 expression does not always correlate with abnormalities on chromosome 11 at band p13 in T-cell acute lymphoblastic leukemia

Blood ◽  
1992 ◽  
Vol 80 (12) ◽  
pp. 3189-3197 ◽  
Author(s):  
TJ Fitzgerald ◽  
GA Neale ◽  
SC Raimondi ◽  
RM Goorha
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Regulatory Element ◽  
Lymphoblastic Leukemia ◽  
Cell Receptor ◽  
Chromosome 11 ◽  
Sensitive Polymerase Chain Reaction ◽  
Frequent Site ◽  
Cell Acute Lymphoblastic Leukemia ◽  
T Cell Lines

Abstract A frequent site for nonrandom recombination in T-cell acute lymphoblastic leukemia (T-ALL) is chromosome 11 at p13. The molecular characterization of a (7;11)(q35;p13) translocation showed that the translocation breakpoint was 2 kb 5′ to the T-ALLbcr locus resulting in the juxtaposition of the T-cell receptor (TCR) beta gene to the rhom-2 gene locus. Northern blot analysis did not detect expression of the rhom-2 gene in the leukemic blasts of the (7;11) translocation. However, using a sensitive polymerase chain reaction (PCR)-based assay, the (7;11) translocation showed a trace expression of rhom-2 at a level of 0.01% of TCR-beta message. Because rhom-2 is considered a proto- oncogene, the significance of the trace expression of rhom-2 in the (7;11) translocation was investigated by comparing the level of rhom-2 expression in 7 additional T-ALLs, normal thymocytes, and CEM (pre-T) and HPB (mature-T) cell lines using the PCR assay. The CEM cells, normal thymocytes, and one patient, whose blasts had no cytogenetic abnormality of chromosome 11, did not express rhom-2 indicating that rhom-2 is not normally expressed in T cells. The other six T-ALLs fell into three categories: (1) two T-ALLs overexpressed rhom-2 in the presence of a translocation; (2) two T-ALLs had trace expression in the presence of a translocation; and (3) two T-ALLs had trace expression with no observable abnormalities on chromosome 11 at p13. Therefore, the data indicate that not all translocations at the T-ALLbcr locus result in overexpression of rhom-2. To account for the sharp contrast in rhom-2 expression seen in these T-ALLs, a model is proposed with a negative regulatory element in the T-ALLbcr locus that is disrupted in some of the cases leading to overexpression of rhom-2.

scholarly journals Loss of mTOR complex 1 induces developmental blockage in early T-lymphopoiesis and eradicates T-cell acute lymphoblastic leukemia cells

2014 ◽  
Vol 111 (10) ◽  
pp. 3805-3810 ◽  
Author(s):  
Takayuki Hoshii ◽  
Atsuo Kasada ◽  
Tomoki Hatakeyama ◽  
Masashi Ohtani ◽  
Yuko Tadokoro ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
Lymphoblastic Leukemia ◽  
Critical Role ◽  
T Cell Development ◽  
Leukemia Cells ◽  
Cell Acute Lymphoblastic Leukemia ◽  
T Cell Progenitors

mTOR is an evolutionarily conserved kinase that plays a critical role in sensing and responding to environmental determinants. Recent studies have shown that fine-tuning of the activity of mTOR complexes contributes to organogenesis and tumorigenesis. Although rapamycin, an allosteric mTOR inhibitor, is an effective immunosuppressant, the precise roles of mTOR complexes in early T-cell development remain unclear. Here we show that mTORC1 plays a critical role in the development of both early T-cell progenitors and leukemia. Deletion ofRaptor, an essential component of mTORC1, produced defects in the earliest development of T-cell progenitors in vivo and in vitro.Deficiency ofRaptorresulted in cell cycle abnormalities in early T-cell progenitors that were associated with instability of the Cyclin D2/D3-CDK6 complexes; deficiency ofRictor, an mTORC2 component, did not have the same effect, indicating that mTORC1 and -2 control T-cell development in different ways. In a model of myeloproliferative neoplasm and T-cell acute lymphoblastic leukemia (T-ALL) evoked by Kras activation,Raptordeficiency dramatically inhibited the cell cycle in oncogenic Kras-expressing T-cell progenitors, but not myeloid progenitors, and specifically prevented the development of T-ALL. Although rapamycin treatment significantly prolonged the survival of recipient mice bearing T-ALL cells, rapamycin-insensitive leukemia cells continued to propagate in vivo. In contrast,Raptordeficiency in the T-ALL model resulted in cell cycle arrest and efficient eradication of leukemia. Thus, understanding the cell-context–dependent role of mTORC1 illustrates the potential importance of mTOR signals as therapeutic targets.

scholarly journals Fusion transcripts FYN-TRAF3IP2 and KHDRBS1-LCK hijack T cell receptor signaling in peripheral T-cell lymphoma, not otherwise specified

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Koen Debackere ◽  
Lukas Marcelis ◽  
Sofie Demeyer ◽  
Marlies Vanden Bempt ◽  
Nicole Mentens ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Cell Lymphoma ◽  
Ex Vivo ◽  
Cell Receptor ◽  
T Cell Lymphoma ◽  
Peripheral T Cell Lymphoma ◽  
Fusion Transcripts ◽  
Not Otherwise Specified

AbstractPeripheral T-cell lymphoma (PTCL) is a heterogeneous group of non-Hodgkin lymphomas with poor prognosis. Up to 30% of PTCL lack distinctive features and are classified as PTCL, not otherwise specified (PTCL-NOS). To further improve our understanding of the genetic landscape and biology of PTCL-NOS, we perform RNA-sequencing of 18 cases and validate results in an independent cohort of 37 PTCL cases. We identify FYN-TRAF3IP2, KHDRBS1-LCK and SIN3A-FOXO1 as new in-frame fusion transcripts, with FYN-TRAF3IP2 as a recurrent fusion detected in 8 of 55 cases. Using ex vivo and in vivo experiments, we demonstrate that FYN-TRAF3IP2 and KHDRBS1-LCK activate signaling pathways downstream of the T cell receptor (TCR) complex and confer therapeutic vulnerability to clinically available drugs.

Impact of TCR status and genotype on outcome in adult T-cell acute lymphoblastic leukemia: a LALA-94 study

Blood ◽  
2005 ◽  
Vol 105 (8) ◽  
pp. 3072-3078 ◽  
Author(s):  
Vahid Asnafi ◽  
Agnes Buzyn ◽  
Xavier Thomas ◽  
Francoise Huguet ◽  
Norbert Vey ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Lymphoblastic Leukemia ◽  
Prospective Trial ◽  
Cell Receptor ◽  
Early Response ◽  
Salvage Treatment ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Relapse Rates ◽  
Intermediate Dose

AbstractPatients with T-cell acute lymphoblastic leukemias (T-ALLs) within the Leucémies Aiguës Lymphoblastiques de l'Adulte-94 (LALA-94) prospective trial were treated with a 4-drug per 4-week induction, with intermediate-dose cytarabine and mitoxantrone salvage treatment for patients not achieving complete remission (CR) in 1 course. Only the latter received allografts, if possible, thus providing an informative setting for assessing early response. Representative patients with T-ALL (91 patients) were classified into surface T-cell receptor (TCR)–expressing T-ALL patients (TCRαβ+ or TCRγδ+), pre-αβ T-ALL patients (cTCRβ+, TCR–), and immature (IM) cTCRβ–, TCR– T-ALL patients; 81 patients underwent genotyping for SIL-TAL1, CALM-AF10, HOX11, and HOX11L2. Overall, CR was obtained in 81 (89%) patients; relapse rate was 62% at 4 years and overall survival (OS) rate was 38%. CR rate was significantly lower in IM T-ALL patients after 1 course (45% vs 87%; P < .001) and after salvage (74% vs 97%; P = .002), with the latter inducing a higher rate of CR (9 [64%] of 14) than initial induction. Once CR was obtained, cumulative relapse rates were similar for IM, pre-αβ, and TCR+ T-ALL patients (P = .51), but were higher in HOX11L2 (83%) and SIL-TAL1 (82%) T-ALL patients compared with other genetic subgroups (48%; P = .05). This was associated with an inferior OS for HOX11L2 T-ALLs (13% vs 47% in HOX11L2-T-ALLs; P = .009). The majority of patients with HOX11 T-ALL underwent allografting, predominantly in second CR, but were not associated with a superior OS. Both TCR and genotypic stratification can therefore contribute to risk-adapted management of adult T-ALLs.

scholarly journals Systemic T Cell–independent Tumor Immunity after Transplantation of Universal Receptor–modified Bone Marrow into SCID Mice

1996 ◽  
Vol 184 (6) ◽  
pp. 2261-2270 ◽  
Author(s):  
Kristen M. Hege ◽  
Keegan S. Cooke ◽  
Mitchell H. Finer ◽  
Krisztina M. Zsebo ◽  
Margo R. Roberts
Keyword(s):  
T Cell ◽  
Ex Vivo ◽  
Lethal Dose ◽  
Cell Receptor ◽  
Scid Mice ◽  
Human Leukemia ◽  
Hematopoietic Stem ◽  
Retroviral Transduction ◽  
Hiv Envelope

Gene modification of hematopoietic stem cells (HSC) with antigen-specific, chimeric, or “universal” immune receptors (URs) is a novel but untested form of targeted immunotherapy. A human immunodeficiency virus (HIV) envelope–specific UR consisting of the extracellular domain of human CD4 linked to the ζ chain of the T cell receptor (CD4ζ) was introduced ex vivo into murine HSC by retroviral transduction. After transplantation into immunodeficient SCID mice, sustained high level expression of CD4ζ was observed in circulating myeloid and natural killer cells. CD4ζ-transplanted mice were protected from challenge with a lethal dose of a disseminated human leukemia expressing HIV envelope. These results demonstrate the ability of chimeric receptors bearing ζ-signaling domains to activate non–T cell effector populations in vivo and thereby mediate systemic immunity.

Immunoglobulin/T-cell receptor gene rearrangements in the diagnostic paradigm of pediatric patients with T-cell acute lymphoblastic leukemia

2012 ◽  
Vol 53 (7) ◽  
pp. 1425-1428 ◽  
Author(s):  
Monika D. Kraszewska ◽  
Małgorzata Dawidowska ◽  
Maria Kosmalska ◽  
Łukasz Sędek ◽  
Władysław Grzeszczak ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Receptor ◽  
Pediatric Patients ◽  
Lymphoblastic Leukemia ◽  
Receptor Gene ◽  
Cell Receptor ◽  
Gene Rearrangements ◽  
Cell Acute Lymphoblastic Leukemia ◽  
T Cell Receptor Gene ◽  
Cell Receptor Gene

scholarly journals CD1: From Molecules to Diseases

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1909 ◽  
Author(s):  
D. Branch Moody ◽  
Sara Suliman
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Cell Receptor ◽  
High Genetic Diversity ◽  
Disease States ◽  
New Research ◽  
Antigen Presenting ◽  
Cluster Of Differentiation

The human cluster of differentiation (CD)1 system for antigen display is comprised of four types of antigen-presenting molecules, each with a distinct functional niche: CD1a, CD1b, CD1c, and CD1d. Whereas CD1 proteins were thought solely to influence T-cell responses through display of amphipathic lipids, recent studies emphasize the role of direct contacts between the T-cell receptor and CD1 itself. Moving from molecules to diseases, new research approaches emphasize human CD1-transgenic mouse models and the study of human polyclonal T cells in vivo or ex vivo in disease states. Whereas the high genetic diversity of major histocompatibility complex (MHC)-encoded antigen-presenting molecules provides a major hurdle for designing antigens that activate T cells in all humans, the simple population genetics of the CD1 system offers the prospect of discovering or designing broadly acting immunomodulatory agents.

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