RESUMEN
An increasing body of evidence supports the involvement of NF1 mutations, constitutional or somatic, in the pathogenesis of gastrointestinal stromal tumors (GISTs). Due to the large size of the NF1 locus, the existence of multiple pseudogenes and the wide spectrum of mechanisms of gene inactivation, the analysis of NF1 gene status is still challenging for most laboratories. Here we sought to assess the efficacy of a recently developed neurofibromin-specific antibody (NFC) in detecting NF1-inactivated GISTs. NFC reactivity was analyzed in a series of 98 GISTs. Of these, 29 were 'NF1-associated' (17 with ascertained NF1 mutations and 12 arising in the context of clinically diagnosed Neurofibromatosis type 1 syndrome and thus considered bona fine NF1 inactivated); 38 were 'NF1-unrelated' (either wild-type or carrying non-pathogenic variants of NF1). Thirty-one additional GISTs with no available information on NF1 gene status or with NF1 gene variants of uncertain pathogenic significance were also included in the analysis. Cases were scored as NFC negative when, in the presence of NFC positive internal controls, no cytoplasmic staining was detected in the neoplastic cells. NFC immunoreactivity was lost in 24/29 (83%) NF1-associated GISTs as opposed to only 2/38 (5%) NF1-unrelated GISTs (P=3e-11). NFC staining loss significantly correlated (P=0.007) with the presence of biallelic NF1 inactivation, due essentially to large deletions or truncating mutations. NFC reactivity was instead retained in two cases in which the NF1 alteration was heterozygous and in one case where the pathogenic NF1 variant, although homo/hemizygous, was a missense mutation predicted not to affect neurofibromin half-life. Overall this study provides evidence that NFC is a valuable tool for identifying NF1-inactivated GISTs, thus serving as a surrogate for molecular analysis.
Asunto(s)
Anticuerpos Monoclonales , Análisis Mutacional de ADN/métodos , Tumores del Estroma Gastrointestinal/genética , Neurofibromina 1/biosíntesis , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , MutaciónRESUMEN
Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. The vast majority of GISTs are driven by oncogenic activation of KIT, PDGFRA or, less commonly, BRAF. Loss of succinate dehydrogenase complex activity has been identified in subsets of KIT/PDGFRA/BRAF-mutation negative tumours, yet a significant fraction of GISTs are devoid of any of such alterations. To address the pathobiology of these 'quadruple-negative' GISTs, we sought to explore the possible involvement of fusion genes. To this end we performed transcriptome sequencing on five KIT/PDGFRA/BRAF-mutation negative, SDH-proficient tumours. Intriguingly, the analysis unveiled the presence of an ETV6-NTRK3 gene fusion. The screening by FISH of 26 additional cases, including KIT/PDGFRA-mutated GISTs, failed to detect other ETV6 rearrangements beside the index case. This was a 'quadruple-negative' GIST located in the rectum, an uncommon primary site for GIST development (â¼4% of all GISTs). The fusion transcript identified encompasses exon 4 of ETV6 and exon 14 of NTRK3 and therefore differs from the canonical ETV6-NTRK3 chimera of infantile fibrosarcomas. However, it retains the ability to induce IRS1 phosphorylation, activate the IGF1R downstream signalling pathway and to be targeted by IGF1R and ALK inhibitors. Thus, the ETV6-NTRK3 fusion might identify a subset of GISTs with peculiar clinicopathological characteristics which could be eligible for such therapies. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Asunto(s)
Neoplasias Gastrointestinales/genética , Neoplasias Gastrointestinales/patología , Tumores del Estroma Gastrointestinal/genética , Mutación/genética , Proteínas Proto-Oncogénicas c-ets/genética , Receptor trkC/genética , Proteínas Represoras/genética , Adulto , Anciano , Anciano de 80 o más Años , Línea Celular Tumoral , Exones/genética , Femenino , Fusión Génica/genética , Humanos , Masculino , Persona de Mediana Edad , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Transcriptoma/genética , Proteína ETS de Variante de Translocación 6RESUMEN
With the rapid advancement of sequencing technologies, next generation sequencing (NGS) analysis has been widely applied in cancer genomics research. More recently, NGS has been adopted in clinical oncology to advance personalized medicine. Clinical applications of precision oncology require accurate tests that can distinguish tumor-specific mutations from artifacts introduced during NGS processes or data analysis. Therefore, there is an urgent need to develop best practices in cancer mutation detection using NGS and the need for standard reference data sets for systematically measuring accuracy and reproducibility across platforms and methods. Within the SEQC2 consortium context, we established paired tumor-normal reference samples and generated whole-genome (WGS) and whole-exome sequencing (WES) data using sixteen library protocols, seven sequencing platforms at six different centers. We systematically interrogated somatic mutations in the reference samples to identify factors affecting detection reproducibility and accuracy in cancer genomes. These large cross-platform/site WGS and WES datasets using well-characterized reference samples will represent a powerful resource for benchmarking NGS technologies, bioinformatics pipelines, and for the cancer genomics studies.
Asunto(s)
Secuenciación del Exoma , Genoma Humano , Neoplasias/genética , Secuenciación Completa del Genoma , Benchmarking , Línea Celular Tumoral , Biología Computacional , Genómica , Humanos , Medicina de PrecisiónRESUMEN
The lack of samples for generating standardized DNA datasets for setting up a sequencing pipeline or benchmarking the performance of different algorithms limits the implementation and uptake of cancer genomics. Here, we describe reference call sets obtained from paired tumor-normal genomic DNA (gDNA) samples derived from a breast cancer cell line-which is highly heterogeneous, with an aneuploid genome, and enriched in somatic alterations-and a matched lymphoblastoid cell line. We partially validated both somatic mutations and germline variants in these call sets via whole-exome sequencing (WES) with different sequencing platforms and targeted sequencing with >2,000-fold coverage, spanning 82% of genomic regions with high confidence. Although the gDNA reference samples are not representative of primary cancer cells from a clinical sample, when setting up a sequencing pipeline, they not only minimize potential biases from technologies, assays and informatics but also provide a unique resource for benchmarking 'tumor-only' or 'matched tumor-normal' analyses.
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Benchmarking , Neoplasias de la Mama/genética , Análisis Mutacional de ADN/normas , Secuenciación de Nucleótidos de Alto Rendimiento/normas , Secuenciación Completa del Genoma/normas , Línea Celular Tumoral , Conjuntos de Datos como Asunto , Células Germinativas , Humanos , Mutación , Estándares de Referencia , Reproducibilidad de los ResultadosRESUMEN
Gastrointestinal stromal tumors (GISTs), the most common mesenchymal tumors of the gastrointestinal tract, are characterized by activating mutations in KIT or PDGFRA genes. The vast majority of GISTs are sporadic, but rare hereditary forms have been reported, often featuring multifocality and younger age of onset. We here report the identification of a novel kindred affected by familial GIST caused by a KIT germline mutation in exon 13 (N655K). No family affected by hereditary GIST due to this KIT variant has been reported in literature so far. We were able to track the mutation in three members of the family (proband, mother, and second-degree cousin), all affected by multiple GISTs. Due to its rarity, the N655K variant is poorly characterized. We conducted in vitro drug sensitivity assays that indicated that most tyrosine kinase inhibitors (TKIs) currently included in the therapeutic armamentarium for GISTs have a limited inhibitory activity toward this mutation. However, when compared to a classical imatinib-resistant KIT mutation (T670I), N655K was slightly more sensitive to imatinib, and encouraging responses were observed with last-generation TKIs.
RESUMEN
Intratumoral immune infiltrate was recently reported in gastrointestinal stromal tumors (GISTs). However, the tumor-intrinsic factors that dictate GIST immunogenicity are still largely undefined. To shed light on this issue, a large cohort (82 samples) of primary untreated GISTs, representative of major clinicopathological variables, was investigated by an integrated immunohistochemical, transcriptomic, and computational approach. Our results indicate that tumor genotype, location, and malignant potential concur to shape the immunogenicity of primary naive GISTs. Immune infiltration was greater in overt GISTs compared with that in lesions with limited malignant potential (miniGISTs), in KIT/PDGFRA-mutated tumors compared with that in KIT/PDGFRA WT tumors, and in PDGFRA-mutated compared with KIT-mutated GISTs. Within the KIT-mutated subset, a higher degree of immune colonization was detected in the intestine. Immune hot tumors showed expression patterns compatible with a potentially proficient but curbed antigen-specific immunity, hinting at sensitivity to immunomodulatory treatments. Poorly infiltrated GISTs, primarily KIT/PDGFRA WT intestinal tumors, showed activation of Hedgehog and WNT/ß-catenin immune excluding pathways. This finding discloses a potential therapeutic vulnerability, as the targeting of these pathways might prove effective by both inhibiting pro-oncogenic signals and fostering antitumor immune responses. Finally, an intriguing anticorrelation between immune infiltration and ANO1/DOG1 expression was observed, suggesting an immunomodulatory activity for anoctamin-1.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Gastrointestinales/inmunología , Tumores del Estroma Gastrointestinal/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Mutación , Adulto , Estudios de Cohortes , Femenino , Neoplasias Gastrointestinales/genética , Neoplasias Gastrointestinales/patología , Tumores del Estroma Gastrointestinal/genética , Tumores del Estroma Gastrointestinal/patología , Humanos , Masculino , Proteínas Proto-Oncogénicas c-kit/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , TranscriptomaAsunto(s)
Antineoplásicos/uso terapéutico , Benzamidas/uso terapéutico , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/cirugía , Piperazinas/uso terapéutico , Pirimidinas/uso terapéutico , Quimioterapia Adyuvante , Progresión de la Enfermedad , Tumores del Estroma Gastrointestinal/patología , Humanos , Mesilato de Imatinib , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/cirugía , Resultado del TratamientoRESUMEN
PURPOSE: Gastrointestinal stromal tumors (GIST) are commonly regarded as solitary tumors. The occurrence of multiple lesions is considered an extraordinary event restricted to pediatric GISTs and rare hereditary conditions. Beyond these well-defined situations, the presentation of multiple synchronous lesions is commonly viewed as the result of the metastatic spreading of a single primary GIST. Based on this axiom, patients with multifocal disease are classified as advanced stage and treated as such. Whether, indeed, the detection of several lesions in sporadic adult GIST patients may be suggestive of phenomena of tumor multiplicity still needs to be clarified. EXPERIMENTAL DESIGN: From a multicentric series of 442 consecutive cases, 26 of which with advanced disease, we selected 5 patients who presented up to three distinct GIST nodules. Five additional cases with similar characteristics were also contributed by two other institutions. The clonal relationship between the synchronous lesions was assessed by comparing KIT/PDGFRA mutation and microsatellite pattern. RESULTS: An independent origin of the synchronous lesions was established in 6 of 10 cases. Notably, in one patient, one lesion arose in the peritoneum, which is ordinarily regarded as a site of metastasis. CONCLUSIONS: Our data indicate that a significant fraction of GIST patients with multifocal presentation are actually affected by multiple primary tumors, suggesting that mesenchymal GIST precursor cells of these individuals are somehow primed to transformation. Thus, in the presence of multifocal GIST manifestations, an accurate characterization of the different tumor sites should be undertaken for a proper patient staging and therapy planning.
Asunto(s)
Tumores del Estroma Gastrointestinal/diagnóstico , Neoplasias Primarias Múltiples/diagnóstico , Anciano , Anciano de 80 o más Años , Secuencia de Aminoácidos , Femenino , Tumores del Estroma Gastrointestinal/genética , Tumores del Estroma Gastrointestinal/patología , Humanos , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Mutación , Neoplasias Primarias Múltiples/genética , Neoplasias Primarias Múltiples/patología , Proteínas Proto-Oncogénicas c-kit/genética , Receptores del Factor de Crecimiento Derivado de Plaquetas/genéticaRESUMEN
Despite the efforts during the last decades to improve clinical management and therapy, carcinomas of the head and neck still represent a disease with an unfavourable course. Over 50% of the patients die from their disease within 5 years after diagnosis, with tumour recurrence, metastasis, and development of second primary neoplasms as major causes of treatment failure. In addition, surgical treatment of locally advanced disease often results in invalidating and disfiguring conditions that heavily affect patients' quality of life. Current criteria of tumour staging, essentially based on clinical and pathological assessment, fail to prove effective in providing reliable information on tumour prognosis or supporting an optimized planning of the therapies, prompting the identification of new and more accurate staging criteria. This review focuses on the impact of molecular biology in HNSCC staging, namely differentiation of second primary lesions from recurrence/metastasis and detection of lymph node micrometastasis, and highlights how the integration of the histopathological diagnosis with molecular analyses may result in a better management of HNSCC patients.
Asunto(s)
Biomarcadores de Tumor/análisis , Carcinoma de Células Escamosas/patología , Neoplasias de Cabeza y Cuello/patología , Técnicas de Diagnóstico Molecular , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Humanos , Estadificación de NeoplasiasRESUMEN
PURPOSE: The majority of gastrointestinal stromal tumors (GIST) are driven by KIT, PDGFRA, or, less commonly, BRAF mutations, and SDH gene inactivation is involved in a limited fraction of gastric lesions. However, about 10% of GISTs are devoid of any of such alterations and are poorly responsive to standard treatments. This study aims to shed light on the molecular drivers of quadruple-negative GISTs. EXPERIMENTAL DESIGN: Twenty-two sporadic quadruple-negative GISTs with no prior association with Neurofibromatosis Type 1 syndrome were molecularly profiled for a panel of genes belonging to tyrosine kinase pathways or previously implicated in GISTs. For comparison purposes, 24 GISTs carrying KIT, PDGFRA, or SDH gene mutations were also analyzed. Molecular findings were correlated to clinicopathologic features. RESULTS: Most quadruple-negative GISTs featured intestinal localization, with a female predilection. About 60% (13/22) of quadruple-negative tumors carried NF1 pathogenic mutations, often associated with biallelic inactivation. The analysis of normal tissues, available in 11 cases, indicated the constitutional nature of the NF1 mutation in 7 of 11 cases, unveiling an unrecognized Neurofibromatosis Type 1 syndromic condition. Multifocality and a multinodular pattern of growth were common findings in NF1-mutated quadruple-negative GISTs. CONCLUSIONS: NF1 gene mutations are frequent in quadruple-negative GISTs and are often constitutional, indicating that a significant fraction of patients with apparently sporadic quadruple-negative GISTs are affected by unrecognized Neurofibromatosis Type 1 syndrome. Hence, a diagnosis of quadruple-negative GIST, especially if multifocal or with a multinodular growth pattern and a nongastric location, should alert the clinician to a possible Neurofibromatosis Type 1 syndromic condition. Clin Cancer Res; 23(1); 273-82. ©2016 AACR.
Asunto(s)
Biomarcadores de Tumor , Tumores del Estroma Gastrointestinal/genética , Neurofibromatosis 1/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Análisis Mutacional de ADN , Femenino , Tumores del Estroma Gastrointestinal/diagnóstico , Tumores del Estroma Gastrointestinal/mortalidad , Tumores del Estroma Gastrointestinal/terapia , Genes de Neurofibromatosis 1 , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Mutación , Neurofibromatosis 1/diagnóstico , Neurofibromatosis 1/mortalidad , Neurofibromatosis 1/terapia , Pronóstico , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-kit/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genéticaRESUMEN
A patient with rheumatoid arthritis (RA) developed an atypical lymphoproliferative disorder (LPD) after methotrexate and cyclosporine A, which regressed after suspension of both drugs. After subsequent treatment with rituximab, the LPD was still undetectable. Anti-tumor necrosis factor a therapy was used when the arthritis relapsed, but an aggressive B-cell non Hodgkin's lymphoma developed. Molecular analyses showed an oligoclonal B-cell expansion at the LPD step. A minor clone with significant sequence homology to B-cell lymphomas arising in Sjogren's syndrome and mixed cryoglobulinemia syndrome, given rise to the non-Hodgkin's lymphoma. Treatment of rheumatoid arthritis associated with lymphoproliferation represents a clinical challenge, and common pathogenetic pathways to lymphoma may occur in different autoimmune diseases.
Asunto(s)
Antirreumáticos/uso terapéutico , Artritis Reumatoide/complicaciones , Inmunosupresores/uso terapéutico , Linfoma de Células B Grandes Difuso/etiología , Trastornos Linfoproliferativos/complicaciones , Anciano , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales de Origen Murino , Antirreumáticos/efectos adversos , Artritis Reumatoide/tratamiento farmacológico , Enfermedades Autoinmunes/complicaciones , Contraindicaciones , Ciclosporina/efectos adversos , Ciclosporina/uso terapéutico , ADN de Neoplasias/genética , Progresión de la Enfermedad , Susceptibilidad a Enfermedades , Etanercept , Femenino , Reordenamiento Génico de Cadena Pesada de Linfocito B , Reordenamiento Génico de Cadena Ligera de Linfocito B , Genes de Inmunoglobulinas , Humanos , Huésped Inmunocomprometido , Inmunoglobulina G/efectos adversos , Inmunoglobulina G/uso terapéutico , Inmunosupresores/efectos adversos , Linfoma de Células B Grandes Difuso/genética , Trastornos Linfoproliferativos/genética , Metotrexato/efectos adversos , Metotrexato/uso terapéutico , Proteínas de Neoplasias/análisis , Proteínas de Neoplasias/genética , Receptores del Factor de Necrosis Tumoral/uso terapéutico , Rituximab , Factor de Necrosis Tumoral alfa/antagonistas & inhibidoresRESUMEN
After an initial benefit from tyrosine kinase inhibitors (TKI), most gastrointestinal stromal tumors (GISTs) eventually develop disease progression or secondary resistance. An altered tumor (immune)phenotype with anaplasia and morphological changes secondary to therapy have occasionally been described in the literature. We present a 52-year old patient, diagnosed with high risk, spindle-cell, GIST (CD117 positive, Pankeratin negative) in 2003, showing a c-Kit exon 11 mutation. After TKI therapy, he developed drug resistance and disease progression. Pathological assessment of the last surgical specimen showed a pure epithelioid/clear cell histology, without evidence of cellular anaplasia. Tumor cells were CD117 positive, DOG1 positive but also E-cadherin positive and Pankeratin positive, whereas molecular analysis confirmed the presence of the c-Kit exon 11 mutation, with no additional mutations. We describe an unusual case of GIST showing peculiar (immuno)phenotypic changes under therapy, different from the vast majority of therapy-driven changes, which include marked cellular pleomorphisms and KIT immunonegativity. Possible molecular explanations to understand these phenomena and a brief review of the literature are also addressed.
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Antineoplásicos/uso terapéutico , Neoplasias Gastrointestinales/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Queratinas/metabolismo , Inhibidores de Proteínas Quinasas/uso terapéutico , Cadherinas/genética , Neoplasias Gastrointestinales/patología , Tumores del Estroma Gastrointestinal/diagnóstico , Humanos , Persona de Mediana Edad , FenotipoRESUMEN
AIM: The BRAF mutation is a rare pathogenetic alternative to KIT/PDGFRA mutation in GIST and causes Imatinib resistance. A recent description of KIT and BRAF mutations co-occurring in an untreated GIST has challenged the concept of their being mutually exclusive and may account for ab initio resistance to Imatinib, even in the presence of Imatinib-sensitive KIT mutations. BRAF sequencing is generally limited to KIT/PDGFRA wild-type cases. Hence, the frequency of concomitant mutations may be underestimated. METHODS: We screened for KIT (exon 9, 11 ,13 ,17), PDGFRA (exon 12,14, 18) and BRAF (exon 15) mutations a series of 407 GIST. Additionally, we evaluated the BRAF V600E mutation-specific antibody, VE1, as a surrogate for V600E mutation, on a series of 313 GIST (24 on whole sections, 288 cases on tissue array), including 6 cases molecularly ascertained to carry the BRAF V600E mutation. RESULTS: No concomitant KIT/BRAF or PDGFRA/BRAF mutations were detected. BRAF mutation was detected only in one case, wild-type for KIT/PDGFRA. All the 6 BRAF-mutant cases stained positive with the VE1 antibody. A weak VE1 expression was observed in 14/287 (4.9%) BRAF wild-type cases, as observed also in 2/6 BRAF-mutant cases. Overall in our series, sensitivity and specificity of the VE1 antobody were 100% and 95.1%, respectively. CONCLUSIONS: The concomitance of BRAF mutation with either KIT or PDGFRA mutation is rare in GIST. In these tumors, moderate/strong VE1 immunoreactivity is a valuable surrogate for molecular analysis. Instead, genotyping is warranted in the presence of weak VE1 staining.
Asunto(s)
Neoplasias Gastrointestinales/genética , Tumores del Estroma Gastrointestinal/genética , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-kit/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/inmunología , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Análisis Mutacional de ADN/métodos , Resistencia a Antineoplásicos , Exones , Femenino , Neoplasias Gastrointestinales/patología , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Tumores del Estroma Gastrointestinal/patología , Genotipo , Humanos , Mesilato de Imatinib/farmacología , Mesilato de Imatinib/uso terapéutico , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Mutación , Proteínas Proto-Oncogénicas B-raf/inmunología , Análisis de Secuencia de ADN , Análisis de Matrices TisularesRESUMEN
Several infectious agents have been associated with development of lymphoproliferative disorders. Among these is hepatitis C virus (HCV), which infects more than 200 million people worldwide. HCV infection has been linked to progression of type II mixed cryoglobulinemia (MC) syndrome and has also been suggested to contribute to development of B-cell non-Hodgkin's lymphoma (NHL). Mechanisms responsible for development of lymphoproliferative disorders among HCV-positive patients remain unclear. Accumulating evidence supports a model in which chronic stimulation of B-cells by antigens associated with HCV infection causes nonmalignant B-cell expansion that may evolve into B-cell NHL. The course of disease among HCV-positive B-cell NHL patients may be complicated by coinfection with other infectious agents. This possibility has been explored by studies that have investigated potential interactions between HCV and human immunodeficiency virus (HIV) as well as between HCV and Epstein-Barr virus (EBV). Further characterization of the mechanisms by which HCV promotes development of lymphoproliferative disorders may improve diagnosis, classification, and treatment of these conditions.
Asunto(s)
Linfocitos B/patología , Hepacivirus , Hepatitis C/complicaciones , Linfoma no Hodgkin/etiología , Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Hepatitis C/patología , Humanos , Trastornos Linfoproliferativos/etiologíaRESUMEN
Although epidemiologic and experimental data suggest an etiopathogenetic role for both hepatitis C virus (HCV) and Epstein-Barr virus (EBV) infection in development of B-cell non-Hodgkin's lymphoma (NHL), potential interactions between EBV and HCV during progression of B-cell NHL have not yet been fully investigated. In the present study, tumor biopsy specimens from patients with both B-cell NHL and chronic HCV infection (HCV(+)) were analyzed for the presence of EBV-encoded RNA (EBER) by in situ hybridization (ISH). VH and VL gene segments were amplified from tumor biopsy specimen DNA by PCR. EBV infection (EBV(+)) was detected in tumors from 2 of 31 (6%) HCV(+) B-cell NHL patients. Clinical histories of these two EBV(+)/HCV(+) B-cell NHL patients indicated a particularly aggressive course of disease. Chemotherapy failed to induce long lasting remission for either of these EBV(+)/HCV(+) B-cell NHL patients. Amplification of CDR3 of the Ig heavy chain gene from DNA isolated from each EBV(+)/HCV(+) B-cell NHL indicated the presence of monoclonal B-cell expansion. Rearrangement of Ig genes in neoplastic B-cell clones from both EBV(+)/HCV(+) patients was similar to that previously reported for EBV(-)/HCV(+) B-cell NHL patients. Additionally, neoplastic B-cell clones from these two EBV(+)/HCV(+) B-cell NHL patients did not exhibit intraclonal variation. Previous studies have demonstrated that intraclonal variation is common among neoplastic B-cell clones from EBV(-)/HCV(+) patients. EBV infection may have prevented evolution of variant neoplastic B-cell clones by suppressing antibody affinity maturation. Together, these data suggest that EBV infection may cooperate with HCV infection during progression of B-cell NHL in immunocompetent individuals. Such an interaction may accelerate the course of disease in B-cell NHL patients.
Asunto(s)
Infecciones por Virus de Epstein-Barr/complicaciones , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/patogenicidad , Linfoma de Células B/patología , Linfoma de Células B/virología , Linfoma no Hodgkin/patología , Linfoma no Hodgkin/virología , Anciano , Transformación Celular Neoplásica , ADN Viral/análisis , Progresión de la Enfermedad , Femenino , Humanos , Inmunocompetencia , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , PronósticoRESUMEN
The mutation status of KIT or PDGFRA notoriously affects the response of advanced gastrointestinal stromal tumors (GISTs) to tyrosine kinase inhibitors. Conversely, it is currently still unclear whether mutation status impinges on the prognosis of localized, untreated GISTs. Hence, at present, this variable is not included in decision making for adjuvant therapy. A series of 451 primary localized GISTs were analyzed for KIT, PDGFRA, and BRAF mutations. Univariable and multivariable analyses and a backward selection procedure were used to assess the impact of mutation status on overall survival and to identify prognostically homogenous groups. Mutation was a significant prognostic indicator of overall survival in naive, localized GISTs (P<0.001): KIT-mutated patients had a worse outcome than PDGFRA-mutated or triple-negative (KIT, PDGFRA, BRAF wild-type) cases. Multivariable Cox regression models allowed us to identify 3 molecular risk groups: group I exhibited the best outcome and included PDGFRA exon 12, BRAF, and KIT exon 13-mutated cases; group II, of intermediate clinical phenotype (HR=3.06), included triple-negative, KIT exon 17, PDGFRA exon 18 D842V, and PDGFRA exon 14-mutated cases; group III displayed the worst outcome (hazard ratio=4.52), and comprised KIT exon 9 and exon 11 and PDGFRA exon 18 mutations apart from D842V. This study highlights the prognostic impact of mutation status on the natural course of GIST and suggests that the molecular prognostic grouping may complement the conventional clinicopathologic risk stratification criteria in decision making for adjuvant therapy.
Asunto(s)
Tumores del Estroma Gastrointestinal/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Proteínas Proto-Oncogénicas c-kit/genética , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Anciano , Antineoplásicos/uso terapéutico , Benzamidas/uso terapéutico , Análisis Mutacional de ADN , Femenino , Tumores del Estroma Gastrointestinal/tratamiento farmacológico , Humanos , Mesilato de Imatinib , Masculino , Persona de Mediana Edad , Piperazinas/uso terapéutico , Pirimidinas/uso terapéuticoRESUMEN
It has been shown that t(14;18)(q32;q21) involving fusion of IGH with MALT1 occurs frequently in mucosa-associated lymphoid tissue (MALT) lymphomas. Results of the present study indicate that the classical form of t(14;18)(q32;q21) involving fusion of IGH with bcl-2 can be detectable in a subset of MALT lymphomas in patients with hepatitis C virus (HCV) infection.
Asunto(s)
Reordenamiento Génico de Linfocito B , Genes bcl-2/genética , Hepatitis C/genética , Linfoma de Células B de la Zona Marginal/genética , Linfoma de Células B de la Zona Marginal/virología , Adulto , Anciano , Femenino , Hepatitis C/complicaciones , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Accumulating evidence support a role for hepatitis C virus (HCV) in the pathogenesis of human lymphoproliferative disorders. Clonal expansions of B lymphocytes have been prevalently detected in the bone marrow, in the liver and in the peripheral blood of HCV-infected patients. Epidemiologic studies have associated HCV infection with an increased risk of B-cell lymphoma development, particularly of those with primary localization to organs target of HCV infection. The analysis of the B-cell receptor variable region sequences in sequential phases of HCV-associated lymphomas provided evidence of an ongoing somatic mutation process still present in the neoplastic cells. A restricted repertoire of V, D, J genes was used to assemble the B-cell receptor, and a frequent occurrence of certain gene combinations (V1-69/D3-22/J4 heavy chain with a V3-20 encoded light chain; V3-7/D3/J3 heavy chain with V3-15/J1 light chain; V3-231D3-22/J4 or V4-59/D2-15/J2 with a V3-20 light chain) was observed, thus suggesting a common antigen-binding specificity for these B-cell clones. The high similarity to antibodies with rheumatoid factor (RF) activity as well as to anti-HCV E2 antibodies suggested that HCV, alone or in complex with IgG, could play a pathogenetic role as an exogenous trigger in certain stages of B-cell lymphoproliferation and in certain subsets of B-cell non-Hodgkin's lymphomas (NHLs). The restricted gene repertoire used to assemble the B-cell receptor observed in HCV-associated B-cell NHLs could have important implications as an antigenic target in anti-tumor immunologic therapies.
Asunto(s)
Linfocitos B/patología , Hepatitis C/complicaciones , Linfoma de Células B/etiología , Médula Ósea/patología , División Celular , Reordenamiento Génico , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Cadenas Ligeras de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Linfoma de Células B/terapia , Receptores de Antígenos de Linfocitos B/fisiologíaRESUMEN
AIMS AND BACKGROUND: Preliminary evidence suggests that hepatitis C virus (HCV) might play a pathogenetic role in autoimmune-related, non-malignant B-cell lymphoproliferation, as well as in a subset of B-cell non-Hodgkin's lymphomas (NHLs). With regard to the mechanism(s) by which HCV might favor B-cell expansion and malignant transformation, most data support an indirect pathogenetic role of the virus as an exogenous trigger. A direct oncogenetic role of HCV by direct cell infection and deregulation has only been hypothesized on the basis of the lymphotropism of the virus. METHODS: In this study we investigated the possible HCV infection of NHL B cells by means of sensitive and quantitative polymerase chain reaction (PCR) on affinity-purified neoplastic cells, and by HCV-specific immunohistochemistry and in situ hybridization. RESULTS: HCV infection of neoplastic B cells was documented in only three cases, namely the low-grade B-cell NHLs that arose in the course of mixed cryoglobulinemia syndrome (MC). HCV infection, below one viral genome per cell, was detectable only by PCR. All the remaining low-grade (one case) and high-grade B-cell NHLs (two cases) were HCV uninfected. Previous immunoglobulin gene analyses were consistent with an antigen-driven B-cell lymphoproliferation in the studied cases. CONCLUSIONS: Overall, our data are consistent with an indirect oncogenetic role of HCV in B-cell lymphomagenesis as an exogenous trigger. Infection of B cells by HCV appears possible in some NHL subsets, but the implications remain unknown.
Asunto(s)
Linfocitos B/patología , Linfocitos B/virología , Hepacivirus/aislamiento & purificación , Hepatitis C/complicaciones , Linfoma de Células B/virología , Anciano , Transformación Celular Neoplásica , Transformación Celular Viral , Femenino , Citometría de Flujo , Hepacivirus/genética , Humanos , Inmunohistoquímica , Inmunofenotipificación , Hibridación in Situ , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , ARN Viral/aislamiento & purificaciónRESUMEN
PURPOSE: An increasing set of B-cell non-Hodgkin lymphomas (B-NHL) show a biased usage of IGKV3-20 and IGKV3-15 immunoglobulin genes, a feature that could be exploited for the development of ready-to-use, broadly applicable cancer vaccines. EXPERIMENTAL DESIGN: The immunogenic properties of clonal IGKV3-20 and IGKV3-15 proteins were analyzed with particular focus on their ability to elicit cross-reactive responses against molecularly related IGKV proteins expressed by different B-cell lymphoproliferative disorders. RESULTS: IGK+ lymphoma patients show humoral and T-cell responses to IGKV3-20 and IGKV3-15 proteins and IGKV3-specific cytotoxic T lymphocytes (CTL) can be easily induced ex vivo. IGKV3-20-specific CTLs cross-react against different IGKV3 proteins, an effect mediated by the presence of 21 shared, sometimes promiscuous, T-cell epitopes, presented by common HLA class I allele products, thus assuring a broad HLA coverage of IGKV3-based vaccines. Many natural epitope variants are carried by IGK light chains expressed by a broad spectrum of B-NHLs and we show that IGKV3-20-specific CTLs cross-react also against several of these variant epitopes. Both humoral and CTL-specific responses were induced by KLH-conjugated IGKV3-20 protein in HLA-A2-transgenic mice and coinjection of IGKV3-20-specific CTLs with IGKV3-20+ or IGKV3-15+ lymphoma cells into SCID mice totally prevented tumor growth, thus confirming the ability of these effectors to mediate efficient and cross-reactive cytotoxic responses also in vivo. CONCLUSIONS: These results provide the rationale to exploit IGKV3 proteins as "off-the-shelf" vaccines for a large fraction of lymphoma patients.