scholarly journals Mutations of the Novel Tumor Suppressor Gene SAMHD1 Are Frequent and Correlate with Decreased Protein Expression in Peripheral T-Cell Lymphomas (PTCL)

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3515-3515
Author(s):  
Georgia Kokaraki ◽  
Ioanna Xagoraris ◽  
Pedro Farrajota Neves Da Silva ◽  
Lesley Ann Sutton ◽  
Raul Maia Falcão ◽  
...  

Abstract Introduction: The SAM domain and HD domain 1 (SAMHD1) protein is a deoxynucleoside triphosphate (dNTP) triphosphohydrolase, which depletes the intracellular dNTP substrates and thus protects the host (human) cells from replication of viruses such as HIV. Mutations of SAMHD1 gene have been linked to Aicardi-Goutières syndrome (AGS). In lymphoid malignancies, SAMHD1 gene mutations have been detected in a subset of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) resulting in decreased SAMHD1 mRNA levels and also mantle cell lymphoma (MCL) among B-cell neoplasms as well as in a subset (20%) of T-prolymphocytic leukemia (T-PLL). Therefore, SAMHD1 may play a role in oncogenesis as a tumor suppressor. In addition, SAMHD1 may confer resistance to cytarabine by hydrolysing their active triphosphate metabolites and its high protein levels correlate with poorer clinical outcome in acute myeloid leukemia. The mutation status of SAMHD1 gene and its expression patterns in peripheral T-cell lymphoma types is not known yet. The purpose of this study was to investigate SAMHD1 gene alterations using next generation sequencing and SAMHD1 protein expression in common types of PTCL. Methods: The study group included 81 adult patients with peripheral T-cell lymphomas (PTCL) including 26 patients with ALK+ anaplastic large cell lymphoma (ALCL), 20 ALK- ALCL, 13 angioimmunoblastic T-cell lymphomas (AILT) and 22 PTCL, not otherwise specified (NOS) with pre-treatment, formalin-fixed, paraffin-embedded (FFPE) tumor tissues available for immunohistochemical analysis. Double immunostaining (SAMHD1/CD68) was used to distinguish CD68+ histiocytes from the neoplastic T-cells. The Ventana autostainer and a previously validated monoclonal antibody for SAMHD1 (#A303-691A; Bethyl Laboratories, San Antonio, TX, USA) was utilized. The percentage of SAMHD1-positive cells was calculated by counting at least 500 tumor cells in each case. In a subset of 28 PTCLs, next generation sequencing (NGS) was performed using FFPE tissues and an enriched custom TruSight gene panel of 52 genes relevant to lymphoma biology. In addition, 3 control tissue samples were included in the analysis. The analysis pipeline was based on GATK best practices guidelines and all variants were annotated using Ensembl VEP v94.5. Freedom from progression (FFP) and overall survival (OS), were the clinical endpoints. Survival analyses were performed using the Kaplan-Meier method (log-rank test). Results: The expression level of SAMHD1 (percentage of positive neoplastic T-cells) varied significantly with AILT showing the highest level (median percentage 80%) as compared to ALK+ ALCL that showed the lowest level (median percentage 40%) of SAMHD1 expression (p=0.019, Kruskall-Wallis test). SAMHD1 mutations were detected for the first time in a subset of PTCL including 4/11 (36%) ALK+ ALCL, 1/5 (20%) ALK- ALCL, 3/6 (50%) AILT and 2/5 (40%) PTCL, NOS. The SAMHD1 gene alterations included missense mutations, nonsense (stopcodon) and splice region mutations. Importantly, reduced level (low percentage of positive tumor cells) of SAMHD1 protein expression was significantly associated with the presence of SAMHD1 mutations. More specifically, the median percentage of SAMHD1+ neoplastic T-cells was 80% in the PTCL group with wild-type SAMHD1 gene compared to 30% in the PTCL group with mutated SAMHD1 gene (p=0.01, Mann-Whitney U test), thus suggesting that alterations of SAMHD1 gene may represent a mechanism of SAMHD1 protein downregulation in a subset of PTCL. SAMHD1 expression or gene alterations did not correlate with FFP or OS in any PTCL histologic type, although the number of patients included in each group was not adequate to draw definite conclusions for prognostic significance. Conclusions: SAMHD1 gene mutations are frequently detected in a subset of PTCL and are associated with reduced expression of SAMHD1 protein. These findings reveal a novel mechanism (SAMHD1 mutations) of SAMHD1 downregulation in PTCL, and further support the tumor suppressor function of SAMHD1 gene in lymphomas. Disclosures Rosenquist Brandell: AbbVie: Honoraria; AstraZeneca: Honoraria; Illumina: Honoraria; Janssen: Honoraria; Roche: Honoraria.

Blood ◽  
1999 ◽  
Vol 93 (10) ◽  
pp. 3487-3493 ◽  
Author(s):  
Dan Jones ◽  
Christopher D.M. Fletcher ◽  
Karen Pulford ◽  
Aliakbar Shahsafaei ◽  
David M. Dorfman

The tumor necrosis factor (TNF) receptor family includes several important markers of activation in T cells. We examined expression patterns of two T-cell-associated members of these receptors, namely CD30 and OX40/CD134, in 148 cases of T-cell lymphoma to identify possible objective immunohistochemical criteria for subclassification of these tumors. CD30 expression was characteristic of tumors with an anaplastic (46/47 cases [98%]) or large-cell (10/21 [48%]) morphology and was seen in only scattered cells in other tumor types. In contrast, large numbers of OX40/CD134+ tumors cells were typical of angioimmunoblastic lymphoma (15/16 [94%]), angiocentric lymphoma (4/4), a subset of large-cell lymphomas (10/21 [48%]), and lymphomas with a prominent histiocytic component (6/7 [86%]). Strong OX40/CD134 and CD30 coexpression was seen in only 4% of tumors, typically those with an anaplastic/Hodgkin’s-like appearance. OX40/CD134 expression was characteristic of tumors composed of activated CD4+ T cells and was not seen in small-cell T-cell lymphomas, lymphoblastic lymphomas, or other tumor types, including B-cell lymphomas or carcinomas. These results suggest that immunostaining for OX40/CD134 may be helpful in subclassification of peripheral T-cell lymphomas and that the patterns of TNF receptor family expression in these tumors may parallel those seen within nonneoplastic helper T-cell subsets.


Hematology ◽  
2006 ◽  
Vol 2006 (1) ◽  
pp. 317-322 ◽  
Author(s):  
Elaine S. Jaffe

Abstract Peripheral T-cell lymphomas (PTLs) are uncommon, accounting for fewer than 10% of all non-Hodgkin lymphomas. Success in therapy of the PTLs has lagged behind that of aggressive B-cell lymphomas, and most PTLs have a poor prognosis. The molecular pathogenesis of most PTLs is also poorly understood. In the WHO classification, clinical features, in conjunction with morphological and immunophenotypic criteria, are relied on to define most disease entities. Functionally, T-cell lymphomas are related to the two major arms of the immune system, the innate and adaptive immune systems. NK cells and T cells of the innate immune system recognize antigen in the absence of MHC antigens and are involved in mucosal immunity. The lymphomas derived from these cells often involve cutaneous and mucosal sites. The expression of cytotoxic molecules in these lymphomas may predispose to apoptosis by tumor cells and normal bystander cells. Hepatosplenic T-cell lymphoma is a systemic disease derived from functionally immature innate effector cells, most often of γδ T-cell origin. In contrast, most nodal T-cell lymphomas belong to the adaptive immune system. Angioimmunoblastic T-cell lymphoma (AILT) is mostly likely derived from follicular helper T-cells (TFH), a finding that explains many of its pathological and clinical features. Studies of these neoplasms may assist in further unraveling the functional diversity of their normal counterparts.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4300-4300
Author(s):  
Stephanie McGregor ◽  
Anant Shah ◽  
Gordana Raca ◽  
Kamran Mirza ◽  
John Anastasi ◽  
...  

Abstract Peripheral T-cell lymphomas are uncommon and account for 10-15% of all non-Hodgkin lymphomas (NHL). The current classification and treatment strategy of peripheral T-cell lymphomas relies on integrating morphology with immunophenotype, genetics and clinical presentation. However, the most common category of peripheral T-cell lymphomas remains peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) reflecting the lack of specific parameters to better define these lymphomas in a biologically relevant way. As our understanding of the biology of peripheral T-cell development continues to improve, several immunophenotypic markers have become available that can delineate peripheral T-cells into functional subsets. It is now recognized that peripheral T-cell lymphomas can arise from both conventional and innate-like T-cells. Classically, peripheral lymphomas with the γδ T-cell receptor (TCR) as well as lymphomas derived from true natural killer (NK) cells are considered to be arising from the innate T-cells whereas T-cell lymphomas with an αβ TCR are assumed to be derived from the adaptive, conventional T-cells. However, several recent studies have identified relatively rare populations of αβ T cells with extremely limited α chain diversity. These T-cells are characterized by the ability to mount immune responses by interacting with non-classical MHC class I antigen presenting molecules even in the absence of intentional priming. The cells within these populations express markers characteristic of NK cells and/or memory T-cells and include cells frequently labeled as “NKT” cells and mucosal-associated invariant T-cells (MAIT). Whether these cells contribute to peripheral T-cell lymphomas is not known. The transcription factor promyelocytic leukemia zinc finger (PLZF) is indispensable for development and maturation of these T-cells. We therefore asked the question whether PLZF expression could be used to identify peripheral T-cell lymphomas derived from these innate like non-conventional T-cells. To answer this question, we generated a tissue microarray that included biopsies from 26 PTCL-NOS, 11 anaplastic large cell lymphomas (ALCL), ALK-, and 13 ALCL, ALK+. Histologically normal tonsil, lymph node, thymus and gastrointestinal biopsies were used as controls. Immunohistochemistry with the PLZF antibody was performed in the clinical immunohistochemistry laboratory. Only rare PLZF positive cells were observed in uninvolved tonsils, lymph nodes, and thymus. In contrast, the intestinal mucosa, which is normally enriched in PLZF positive innate type T-cells showed a relative abundance with expression observed in 8-10% lymphocytes. Lymphomas were scored as positive when 20% or more of tumor cells showed expression with nuclear localization. Within the lymphomas, PLZF expression was observed in 2/26 PTCL-NOS and 2/13 ALCL, ALK+. PLZF expression was not observed in any of the ALCL, ALK- lymphomas included in the current study. PCR amplification followed by sequencing identified the Vα7.2-Jα33 TCR rearrangement characteristic of the MAIT cells in the two PLZF positive PTCL-NOS lymphomas confirming the origin of these lymphomas from bona fide innate-like T-cells. Sequencing of the TCR in the remaining three PLZF positive lymphomas is currently in progress. Cytogenetic analysis was available in three of the 4 cases. While t(2;5) was the sole cytogenetic abnormality in one ALCL, ALK+ lymphoma, the remaining two cases, including one ALCL, ALK+ had a complex karyotype that included t(2;5). In view of the relatively small number of patients available for analysis and the heterogeneous therapy administered to patients included retrospectively in the study, an outcome analysis was not performed. In conclusion, we demonstrate that PLZF expression identifies lymphomas derived from non-conventional innate-like T-cells and likely represent a biologically unique group of peripheral T-cell lymphoma. It is well known that innate T-cells are highly resistant to xenobiotics due to high expression of the transporter ATP binding cassette B1 (MDR). Prospective evaluation for PLZF expression may therefore be useful in identifying patients who will benefit from therapy that specifically targets this pathway of drug resistance. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2927-2927 ◽  
Author(s):  
Yosaku Watatani ◽  
Yasuharu Sato ◽  
Kenji Nishida ◽  
Hiroaki Miyoshi ◽  
Yuichi Shiraishi ◽  
...  

Abstract Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of lymphoproliferative disorders arising from mature T-cells. Among them, PTCL-not otherwise specified (PTCL-NOS) is a diagnosis of exclusion, comprising the largest fraction of PTCL with a diverse underlying pathogenesis. Recently, the concept of nodal T-cell lymphomas with T-follicular helper (TFH) phenotype, including angioimmunoblastic T-cell lymphoma (AITL) and PTCL-NOS that manifests a TFH phenotype, has been proposed, a distinguishing feature of which is the high frequency of TET2, IDH2, DNMT3A, and RHOA(G17V) mutations. Although recent large-scale genetic studies have uncovered mutational landscapes of several other subtypes of PTCLs, such as cutaneous T-cell lymphoma and adult T-cell leukemia/lymphoma (ATL), the entire picture of somatic alterations in PTCL-NOS still remains elusive. In addition, their similarities and differences among various histological subtypes in PTCLs have not been fully elucidated. To address this issue, we initially analyzed our and publicly available whole-exome/genome as well as transcriptome sequencing data from PTCL-NOS and other related PTCLs. Then, we carried out an extensive investigation of somatic mutations and structural variations (SVs) in PTCL-NOS using targeted-capture sequencing of 118 PTCL-NOS samples. Consistent with previous reports, TET2 (35%) was the most frequently mutated gene in PTCL-NOS with the majority (78%) affected by multiple mutations, followed by RHOA (25%), TP53 (16%), KMT2C (12%), PLCG1 (12%), and HLA-B (11%). Besides them, a considerable proportion of patients harbored mutations in components of T-cell receptor (TCR) /NF-κB pathway (such as PRKCB, CARD11, IRF4, and PRDM1), other signal transduction molecules (STAT3, NOTCH1, and SOCS1), chemokine receptors (CCR4 and CCR7), epigenetic modifiers (CREBBP, KDM6A, IDH2, and DNMT3A), transcriptional regulators (GATA3 and TBL1XR1), and molecules associated with immune evasion (HLA-A, HLA-B, FAS, B2M, and CD58). In addition to deteriorating SVs involving frequently affected genes (TP53, FAS, GATA3, and TBL1XR1), we discovered several genes almost exclusively affected by SVs, including TP73, IKZF2, and NFKB2, and CD274. Novel targets of recurrent mutation were also identified, including PDCD1, YTHDF2, and LRP1B, which were frequently targeted by nonsense and frameshift mutations distributed throughout the entire genes. Among them, PDCD1encodes PD-1 receptor transmitting an inhibitory signal from PD-L1 and PD-L2 ligands in T cells, and its loss of function seems to enable tumor cells to escape from the suppression by this negative signal. Although the roles of YTHDF2, a reader protein of N6-methyladenosine, and LRP1B, a member of the low density lipoprotein receptor family, in T cells are not immediately apparent, these findings shed light on a new biological function of these genes. Next, we investigated the co-existence relationship between frequently altered genes in PTCL-NOS. Interestingly, mutations characteristic of TFH lymphomas (TET2, RHOA, IDH2, and DNMT3A) tended to co-occur in a subset of PTCL-NOS cases, whereas they were almost mutually exclusive with mutations in TP53 and TCR/NF-κB pathway genes. This observation reveals the molecular distinction between TFH and non-TFH lymphomas in PTCL-NOS: the former is similar to AITL, although TET2 mutations did not show higher allelic burden than RHOA and IDH2mutations. In contrast, the latter is at least partly characterized by the genetic alterations shared with ATL. In summary, our findings illuminate the landscape of somatic alterations in PTCL-NOS and provide a novel insight into their genetic and molecular heterogeneity, which would help us to exploit a new therapeutic strategy to combat this disease. Disclosures Ohshima: CHUGAI PHARMACEUTICAL CO.,LTD.: Research Funding, Speakers Bureau; Kyowa Hakko Kirin Co., Ltd.: Research Funding, Speakers Bureau. Ogawa:Kan research institute: Consultancy, Research Funding; Sumitomo Dainippon Pharma: Research Funding; Takeda Pharmaceuticals: Consultancy, Research Funding. Kataoka:Kyowa Hakko Kirin: Honoraria; Yakult: Honoraria; Boehringer Ingelheim: Honoraria.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 18513-18513
Author(s):  
D. Morales ◽  
B. E. Beltran ◽  
C. Castañeda ◽  
A. Carrasco ◽  
P. Quiñones ◽  
...  

18513 Background: Foxp3 is a key regulatory gene required for the development and function of: regulatory CD4+CD25high T cells (Treg) specialized in maintaining the balance between immunity and tolerance and activated conventional CD4+CD25low T cells without suppressive activity. Previous studies had reported the origin of Adult T-cell Leukemia/Lymphoma cells (ATLL) in Foxp3 T cells and in other lymphomas types the FOXP3 expression was only detected in the reactive T-cell background. Our objetive was to determine the presence of Treg phenotype cells by the FOXP3 expression in T-cell lymphomas. Methods: A retrospective study was performed on 48 samples collected from diverse T-cell lymphomas in our institution. A highly sensitive immunohistochemical method was used to demonstrate Treg phenotype by FOXP3 protein expression with a mouse monoclonal antibody (clone 236A/E7ABCAM) in most formalin-fixed paraffin-embedded tissue sections from lymph nodes, skin, bone marrow and extranodal sites samples as cavum and stomach. We did not co-stained with CD25 and considered a FOXP3+ tissue when positivity was > 20% of tumor cells. The statistical method was descriptive and survival was calculated using the Kaplan-Meier method. Results: Among the 48 evaluable T-cell lymphomas collected, 33 were ATLL, 8 unspecified peripheral T-cell lymphomas (U-PTCL), 6 mycosis fungoides (MF) and 1 cutaneous aggressive epidermotropic CD8(+) cytotoxic T-cell lymphoma. Among the 33 ATLL: lymphomatous=17, acute=11, smoldering=1, chronic=1, cutaneous=1 and undefined=2. FOXP3 expression in tumour cells was detected in 24% (8/33) of ATLL cases and in 37% (3/8) of U-PTCL. It was negative in MF tumour cells and aggressive epidermotropic CD8(+) cytotoxic T-cell lymphoma Among the ATLL cases FOXP3 positivity were obtained in 35% (6/17) of lymphomatous type; 18% (2/11) of acute ones and none in others ATLL types studied. Interestingly 3 U-PTCL had Treg phenotype and were related to EBV (LMP1 positive); two had extranodal primary ( parotide and cavum) and one was nodal. We failed to demonstrate any correlation between FOXP3 status and survival. Conclusions: Some ATLL and U-PTCL had Treg phenotype. In our work Foxp3 expression was not found to be a prognostic factor. No significant financial relationships to disclose.


Hematology ◽  
2008 ◽  
Vol 2008 (1) ◽  
pp. 272-279 ◽  
Author(s):  
Laurence de Leval ◽  
Philippe Gaulard

Abstract Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of rare diseases, usually manifesting clinical aggressiveness. Although important novel insights into the pathobiology of nodal PTCL have been gained recently from molecular profiling studies and clinico-pathological analyses, the pathogenetic molecular lesions remain to be deciphered for most entities. Angioimmunoblastic T-cell lymphoma (AITL) comprises CD4+ CXCL13+ neoplastic cells displaying overlapping immunophenotypical and molecular features with normal follicular helper T cells. This derivation might account for the presence of a prominent non-neoplastic component in AITL tissues and the clinical manifestations of the disease reflective of an immunological dysfunction. ALK+ anaplastic large cell lymphoma (ALCL), defined by ALK gene translocation with various gene partners, is composed of CD30+ ALK+ cells with a cytotoxic phenotype and usually carries a good prognosis. ALK– ALCL, now considered as a distinct disease entity, is morphologically and immunophenotypically similar to ALK+ ALCL, except for ALK expression, but has distinctive molecular features. PTCL, not otherwise specified (PTCL, NOS), the largest PTCL category, which is derived from activated CD4+ (or CD8+) T cells, is markedly heterogeneous, including at the molecular level. Gene expression profiling approaches have identified novel biomarkers of potential therapeutic interest, and suggest the existence of molecularly distinct PTCL, NOS subgroups.


1981 ◽  
Vol 154 (6) ◽  
pp. 1957-1964 ◽  
Author(s):  
M Robert-Guroff ◽  
F W Ruscetti ◽  
L E Posner ◽  
B J Poiesz ◽  
R C Gallo

A monoclonal antibody specific for the internal p19 protein of a type-C retrovirus (HTLV) isolated from human neoplastic T cells has been developed. Its specificity has been shown by radioimmune precipitation and by affinity chromatography of iodinated HTLV proteins. By indirect immune fluorescence this antibody recognizes only HTLV-producing cells. Examination of cells from patients with cutaneous T cell lymphomas and leukemias and with other types of lymphomas and leukemias indicated that HTLV p19 expression is rare. The monoclonal antibody will be useful in determining the natural reservoir of HTLV, possibly in a subset of mature T cell neoplasias.


Blood ◽  
2012 ◽  
Vol 119 (15) ◽  
pp. 3534-3538 ◽  
Author(s):  
Filiberto Cedeno-Laurent ◽  
Rei Watanabe ◽  
Jessica E. Teague ◽  
Thomas S. Kupper ◽  
Rachael A. Clark ◽  
...  

Tumor-derived galectin-1 (Gal-1), a β-galactoside–binding S-type lectin, has been shown to encourage T-cell death and promote T cell–mediated tumor immune escape. In this report, we show that patients with leukemic cutaneous T-cell lymphomas, known to have limited complexity of their T-cell repertoires, have a predominant T helper type-2 (Th2) cytokine profile and significantly elevated plasma levels of Gal-1 compared with healthy controls. Circulating clonal malignant T cells were a major source of Gal-1. The conditioned supernatant of cultured malignant T cells induced a β-galactoside–dependent inhibition of normal T-cell proliferation and a Th2 skewing of cytokine production. These data implicate Gal-1 in development of the Th2 phenotype in patients with advanced-stage cutaneous T-cell lymphoma and highlight the Gal-1–Gal-1 ligand axis as a potential therapeutic target for enhancing antitumor immune responses.


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