RESUMO
BACKGROUND: Whereas human leukocyte antigen (HLA) class I mutation-associated neoantigen burden has been linked with response to immune checkpoint blockade (ICB), the role of HLA class II-restricted neoantigens in clinical responses to ICB is less studied. We used computational approaches to assess HLA class II immunogenic mutation (IMM) burden in patients with melanoma and lung cancer treated with ICB. PATIENTS AND METHODS: We analyzed whole-exome sequence data from four cohorts of ICB-treated patients with melanoma (n = 110) and non-small-cell lung cancer (NSCLC) (n = 123). MHCnuggets, a neural network-based model, was applied to estimate HLA class II IMM burdens and cellular fractions of IMMs were calculated to assess mutation clonality. We evaluated the combined impact of HLA class II germline genetic variation and class II IMM burden on clinical outcomes. Correlations between HLA class II IMM burden and density of tumor-infiltrating lymphocytes were computed from expression data. RESULTS: Responding tumors harbored a significantly higher HLA class II IMM burden for both melanoma and NSCLC (P ≤ 9.6e-3). HLA class II IMM burden was correlated with longer survival, particularly in the NSCLC cohort and in the context of low intratumoral IMM heterogeneity (P < 0.001). HLA class I and II IMM landscapes were largely distinct suggesting a complementary role for class II IMMs in tumor rejection. A higher HLA class II IMM burden was associated with CD4+ T-cell infiltration and programmed death-ligand 1 expression. Transcriptomic analyses revealed an inflamed tumor microenvironment for tumors harboring a high HLA class II IMM burden. CONCLUSIONS: HLA class II IMM burden identified patients with NSCLC and melanoma that attained longer survival after ICB treatment. Our findings suggest that HLA class II IMMs may impact responses to ICB in a manner that is distinct and complementary to HLA class I-mediated responses.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Melanoma , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Antígenos HLA , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Mutação , Microambiente TumoralRESUMO
BACKGROUND: Accurate detection of patients with minimal residual disease (MRD) after surgery for stage II colon cancer (CC) remains an urgent unmet clinical need to improve selection of patients who might benefit form adjuvant chemotherapy (ACT). Presence of circulating tumor DNA (ctDNA) is indicative for MRD and has high predictive value for recurrent disease. The MEDOCC-CrEATE trial investigates how many stage II CC patients with detectable ctDNA after surgery will accept ACT and whether ACT reduces the risk of recurrence in these patients. METHODS/DESIGN: MEDOCC-CrEATE follows the 'trial within cohorts' (TwiCs) design. Patients with colorectal cancer (CRC) are included in the Prospective Dutch ColoRectal Cancer cohort (PLCRC) and give informed consent for collection of clinical data, tissue and blood samples, and consent for future randomization. MEDOCC-CrEATE is a subcohort within PLCRC consisting of 1320 stage II CC patients without indication for ACT according to current guidelines, who are randomized 1:1 into an experimental and a control arm. In the experimental arm, post-surgery blood samples and tissue are analyzed for tissue-informed detection of plasma ctDNA, using the PGDx elio™ platform. Patients with detectable ctDNA will be offered ACT consisting of 8 cycles of capecitabine plus oxaliplatin while patients without detectable ctDNA and patients in the control group will standard follow-up according to guideline. The primary endpoint is the proportion of patients receiving ACT when ctDNA is detectable after resection. The main secondary outcome is 2-year recurrence rate (RR), but also includes 5-year RR, disease free survival, overall survival, time to recurrence, quality of life and cost-effectiveness. Data will be analyzed by intention to treat. DISCUSSION: The MEDOCC-CrEATE trial will provide insight into the willingness of stage II CC patients to be treated with ACT guided by ctDNA biomarker testing and whether ACT will prevent recurrences in a high-risk population. Use of the TwiCs design provides the opportunity to randomize patients before ctDNA measurement, avoiding ethical dilemmas of ctDNA status disclosure in the control group. TRIAL REGISTRATION: Netherlands Trial Register: NL6281/NTR6455 . Registered 18 May 2017, https://www.trialregister.nl/trial/6281.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Biomarcadores Tumorais/sangue , DNA Tumoral Circulante/sangue , Neoplasias do Colo/terapia , Recidiva Local de Neoplasia/epidemiologia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/normas , Capecitabina/administração & dosagem , Capecitabina/efeitos adversos , Quimioterapia Adjuvante/economia , Quimioterapia Adjuvante/psicologia , Quimioterapia Adjuvante/normas , Quimioterapia Adjuvante/estatística & dados numéricos , Colectomia , Neoplasias do Colo/sangue , Neoplasias do Colo/diagnóstico , Neoplasias do Colo/mortalidade , Análise Custo-Benefício , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Biópsia Líquida , Masculino , Recidiva Local de Neoplasia/prevenção & controle , Estadiamento de Neoplasias , Neoplasia Residual , Países Baixos/epidemiologia , Oxaliplatina/administração & dosagem , Oxaliplatina/efeitos adversos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Guias de Prática Clínica como Assunto , Estudos Prospectivos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Background: Neoadjuvant anti-PD-1 may improve outcomes for patients with resectable NSCLC and provides a critical window for examining pathologic features associated with response. Resections showing major pathologic response to neoadjuvant therapy, defined as ≤10% residual viable tumor (RVT), may predict improved long-term patient outcome. However, %RVT calculations were developed in the context of chemotherapy (%cRVT). An immune-related %RVT (%irRVT) has yet to be developed. Patients and methods: The first trial of neoadjuvant anti-PD-1 (nivolumab, NCT02259621) was just reported. We analyzed hematoxylin and eosin-stained slides from the post-treatment resection specimens of the 20 patients with non-small-cell lung carcinoma who underwent definitive surgery. Pretreatment tumor biopsies and preresection radiographic 'tumor' measurements were also assessed. Results: We found that the regression bed (the area of immune-mediated tumor clearance) accounts for the previously noted discrepancy between CT imaging and pathologic assessment of residual tumor. The regression bed is characterized by (i) immune activation-dense tumor infiltrating lymphocytes with macrophages and tertiary lymphoid structures; (ii) massive tumor cell death-cholesterol clefts; and (iii) tissue repair-neovascularization and proliferative fibrosis (each feature enriched in major pathologic responders versus nonresponders, P < 0.05). This distinct constellation of histologic findings was not identified in any pretreatment specimens. Histopathologic features of the regression bed were used to develop 'Immune-Related Pathologic Response Criteria' (irPRC), and these criteria were shown to be reproducible amongst pathologists. Specifically, %irRVT had improved interobserver consistency compared with %cRVT [median per-case %RVT variability 5% (0%-29%) versus 10% (0%-58%), P = 0.007] and a twofold decrease in median standard deviation across pathologists within a sample (4.6 versus 2.2, P = 0.002). Conclusions: irPRC may be used to standardize pathologic assessment of immunotherapeutic efficacy. Long-term follow-up is needed to determine irPRC reliability as a surrogate for recurrence-free and overall survival.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/terapia , Pulmão/patologia , Adulto , Antineoplásicos Imunológicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Estudos de Viabilidade , Humanos , Ipilimumab/farmacologia , Ipilimumab/uso terapêutico , Pulmão/imunologia , Pulmão/cirurgia , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Terapia Neoadjuvante/métodos , Neoplasia Residual , Nivolumabe/farmacologia , Nivolumabe/uso terapêutico , Pneumonectomia , Prognóstico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Reprodutibilidade dos Testes , Resultado do TratamentoRESUMO
Juvenile polyposis (JP; OMIM 174900) is an autosomal dominant gastrointestinal hamartomatous polyposis syndrome in which patients are at risk for developing gastrointestinal cancers. Previous studies have demonstrated a locus for JP mapping to 18q21.1 (ref. 3) and germline mutations in the homolog of the gene for mothers against decapentaplegic, Drosophila, (MADH4, also known as SMAD4) in several JP families. However, mutations in MADH4 are only present in a subset of JP cases, and although mutations in the gene for phosphatase and tensin homolog (PTEN) have been described in a few families, undefined genetic heterogeneity remains. Using a genome-wide screen in four JP kindreds without germline mutations in MADH4 or PTEN, we identified linkage with markers from chromosome 10q22-23 (maximum lod score of 4.74, straight theta=0.00). We found no recombinants using markers developed from the vicinity of the gene for bone morphogenetic protein receptor 1A (BMPR1A), a serine-threonine kinase type I receptor involved in bone morphogenetic protein (BMP) signaling. Genomic sequencing of BMPR1A in each of these JP kindreds disclosed germline nonsense mutations in all affected kindred members but not in normal control individuals. These findings indicate involvement of an additional gene in the transforming growth factor-beta (TGF-beta) superfamily in the genesis of JP, and document an unanticipated function for BMP in colonic epithelial growth control.
Assuntos
Polipose Adenomatosa do Colo/genética , Mutação em Linhagem Germinativa , Proteínas Serina-Treonina Quinases/genética , Receptores de Fatores de Crescimento/genética , Proteínas Supressoras de Tumor , Polipose Adenomatosa do Colo/patologia , Adolescente , Adulto , Receptores de Proteínas Morfogenéticas Ósseas Tipo I , Criança , Pré-Escolar , Cromossomos Humanos Par 10 , Proteínas de Ligação a DNA/genética , Éxons , Feminino , Síndrome do Hamartoma Múltiplo/genética , Síndrome do Hamartoma Múltiplo/patologia , Humanos , Escore Lod , Perda de Heterozigosidade , Masculino , Repetições de Microssatélites , Pessoa de Meia-Idade , Dados de Sequência Molecular , PTEN Fosfo-Hidrolase , Monoéster Fosfórico Hidrolases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Proteína Smad4 , Transativadores/genéticaRESUMO
The characteristics of an organism are determined by the genes expressed within it. A method was developed, called serial analysis of gene expression (SAGE), that allows the quantitative and simultaneous analysis of a large number of transcripts. To demonstrate this strategy, short diagnostic sequence tags were isolated from pancreas, concatenated, and cloned. Manual sequencing of 1000 tags revealed a gene expression pattern characteristic of pancreatic function. New pancreatic transcripts corresponding to novel tags were identified. SAGE should provide a broadly applicable means for the quantitative cataloging and comparison of expressed genes in a variety of normal, developmental, and disease states.
Assuntos
Expressão Gênica , Técnicas Genéticas , Pâncreas/enzimologia , RNA Mensageiro/genética , Sequência de Bases , Clonagem Molecular , Enzimas de Restrição do DNA , DNA Complementar/genética , Biblioteca Gênica , Humanos , Dados de Sequência Molecular , Reação em Cadeia da PolimeraseRESUMO
As a step toward understanding the complex differences between normal and cancer cells in humans, gene expression patterns were examined in gastrointestinal tumors. More than 300,000 transcripts derived from at least 45,000 different genes were analyzed. Although extensive similarity was noted between the expression profiles, more than 500 transcripts that were expressed at significantly different levels in normal and neoplastic cells were identified. These data provide insight into the extent of expression differences underlying malignancy and reveal genes that may prove useful as diagnostic or prognostic markers.
Assuntos
Fenômenos Fisiológicos do Sistema Digestório , Neoplasias Gastrointestinais/genética , Expressão Gênica , Neoplasias Colorretais/genética , Simulação por Computador , Humanos , Valores de Referência , Células Tumorais CultivadasRESUMO
To gain insights into the molecular basis for metastasis, we compared the global gene expression profile of metastatic colorectal cancer with that of primary cancers, benign colorectal tumors, and normal colorectal epithelium. Among the genes identified, the PRL-3 protein tyrosine phosphatase gene was of particular interest. It was expressed at high levels in each of 18 cancer metastases studied but at lower levels in nonmetastatic tumors and normal colorectal epithelium. In 3 of 12 metastases examined, multiple copies of the PRL-3 gene were found within a small amplicon located at chromosome 8q24.3. These data suggest that the PRL-3 gene is important for colorectal cancer metastasis and provide a new therapeutic target for these intractable lesions.
Assuntos
Neoplasias Colorretais/enzimologia , Neoplasias Colorretais/genética , Proteínas Imediatamente Precoces/genética , Metástase Neoplásica/genética , Proteínas Tirosina Fosfatases/genética , Adenoma/enzimologia , Adenoma/genética , Adenoma/patologia , Mapeamento Cromossômico , Cromossomos Humanos Par 8 , Colo/enzimologia , Neoplasias Colorretais/patologia , Amplificação de Genes , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Biblioteca Gênica , Humanos , Proteínas Imediatamente Precoces/metabolismo , Mucosa Intestinal/enzimologia , Proteínas de Neoplasias , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase , Proteínas Tirosina Fosfatases/metabolismo , Reto/enzimologiaRESUMO
To gain a molecular understanding of tumor angiogenesis, we compared gene expression patterns of endothelial cells derived from blood vessels of normal and malignant colorectal tissues. Of over 170 transcripts predominantly expressed in the endothelium, 79 were differentially expressed, including 46 that were specifically elevated in tumor-associated endothelium. Several of these genes encode extracellular matrix proteins, but most are of unknown function. Most of these tumor endothelial markers were expressed in a wide range of tumor types, as well as in normal vessels associated with wound healing and corpus luteum formation. These studies demonstrate that tumor and normal endothelium are distinct at the molecular level, a finding that may have significant implications for the development of anti-angiogenic therapies.
Assuntos
Colo/irrigação sanguínea , Neoplasias Colorretais/irrigação sanguínea , Endotélio Vascular/metabolismo , Perfilação da Expressão Gênica , Neovascularização Patológica/genética , Reto/irrigação sanguínea , Biomarcadores Tumorais , Separação Celular , Células Cultivadas , Colo/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Corpo Lúteo/irrigação sanguínea , Corpo Lúteo/metabolismo , Endotélio Vascular/citologia , Endotélio Vascular/patologia , Proteínas da Matriz Extracelular/genética , Feminino , Expressão Gênica , Humanos , Mucosa Intestinal/irrigação sanguínea , Mucosa Intestinal/citologia , Mucosa Intestinal/patologia , Neoplasias/irrigação sanguínea , Neoplasias/genética , Neoplasias/metabolismo , Neovascularização Fisiológica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reto/metabolismo , Células Tumorais CultivadasRESUMO
Micro-RNAs (miRNAs) are a large class of small non-coding RNAs that regulate protein expression in eucaryotic cells. Initially believed to be unique to the nematode Caenorhabditis elegans, miRNAs are now recognized to be important gene regulatory elements in multicellular organisms and have been implicated in a variety of disease processes, including cancer. Advances in expression technologies have facilitated the high-throughput analysis of small RNAs, identifying novel miRNAs and showing that these genes may be aberrantly expressed in various human tumors. These studies suggest that miRNA expression profiling can be correlated with disease pathogenesis and prognosis, and may ultimately be useful in the management of human cancer.
Assuntos
Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/metabolismo , Neoplasias/diagnóstico , Perfilação da Expressão Gênica , Humanos , MicroRNAs/genética , MicroRNAs/isolamento & purificação , Neoplasias/genética , Neoplasias/metabolismo , Análise de Sequência com Séries de OligonucleotídeosRESUMO
Methods of comprehensive gene expression analysis have traditionally been limited to analysing bulk tissue or millions of cells. New modifications of serial analysis of gene expression (SAGE) have now permitted the analysis of gene expression in cell subpopulations or microanatomic structures, providing access to unexplored transcriptomes of normal and disease biology.
Assuntos
DNA Complementar/genética , Etiquetas de Sequências Expressas , Perfilação da Expressão Gênica , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica , Animais , DNA Complementar/biossíntese , DNA de Neoplasias/genética , Bases de Dados Factuais , Humanos , Internet , Microquímica/métodos , Vírus da Leucemia Murina de Moloney/enzimologia , Neoplasias/genética , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA/metabolismoRESUMO
Analysis of global gene expression in Saccharomyces cerevisiae by the serial analysis of gene expression technique has permitted the identification of at least 302 previously unidentified transcripts from nonannotated open reading frames (NORFs). Transcription of one of these, NORF5/HUG1 (hydroxyurea and UV and gamma radiation induced), is induced by DNA damage, and this induction requires MEC1, a homolog of the ataxia telangiectasia mutated (ATM) gene. DNA damage-specific induction of HUG1, which is independent of the cell cycle stage, is due to the alleviation of repression by the Crt1p-Ssn6p-Tup1p complex. Overexpression of HUG1 is lethal in combination with a mec1 mutation in the presence of DNA damage or replication arrest, whereas a deletion of HUG1 rescues the lethality due to a mec1 null allele. HUG1 is the first example of a NORF with important biological functional properties and defines a novel component of the MEC1 checkpoint pathway.
Assuntos
Ciclo Celular/fisiologia , Dano ao DNA/fisiologia , Inibidores Enzimáticos , Proteínas Fúngicas/metabolismo , Perfilação da Expressão Gênica , Proteínas Nucleares , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/fisiologia , Proteínas de Ligação a DNA/metabolismo , Bases de Dados Factuais , Proteínas Fúngicas/genética , Deleção de Genes , Regulação Fúngica da Expressão Gênica , Hidroxiureia/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular , Modelos Biológicos , Fases de Leitura Aberta , Proteínas Serina-Treonina Quinases , Proteínas Repressoras/metabolismo , Supressão Genética , Transcrição GênicaRESUMO
The p53-regulated gene product p21WAF1/CIP1 is the prototype of a family of small proteins that negatively regulate the cell cycle. To learn more about p21WAF1/CIP1 regulation in vivo, monoclonal antibodies were developed for immunohistochemistry. These revealed that p21WAF1/CIP1 expression followed radiation-induced DNA damage in human skin in a pattern consistent with its regulation by p53. A detailed comparison of the human, rat, and mouse p21WAF1/CIP1 promoter sequences revealed that this induction was probably mediated by conserved p53-binding sites upstream of the transcription start site. In unirradiated tissues, p21WAF1/CIP1 expression was apparently independent of p53 and was observed in a variety of cell types. Moreover, there was a striking compartmentalization of p21WAF1/CIP1 expression throughout the gastrointestinal tract that correlated with proliferation rather than differentiation. As epithelial cells migrated up the crypts, the Ki67-expressing proliferating compartment near the crypt base ended abruptly, with the coincident appearance of a nonproliferating compartment expressing p21WAF1/CIP1. In colonic neoplasms, this distinct compartmentalization was largely abrogated. Cell cycle inhibitors are thus subject to precise topological control, and escape from this regulation may be a critical feature of neoplastic transformation.
Assuntos
Ciclinas/metabolismo , Adenoma/genética , Animais , Anticorpos Monoclonais/imunologia , Sequência de Bases , Carcinoma/genética , Neoplasias Colorretais/genética , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/genética , Primers do DNA/química , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Ratos , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico , Pele/metabolismo , Transcrição Gênica , Proteína Supressora de Tumor p53/fisiologiaRESUMO
The tumor growth suppressor WAF1/CIP1 was recently shown to be induced by p53 and to be a potent inhibitor of cyclin-dependent kinases. In the present studies, we sought to determine the relationship between the expression of WAF1/CIP1 and endogenous regulation of p53 function. WAF1/CIP1 protein was first localized to the nucleus of cells containing wild-type p53 and undergoing G1 arrest. WAF1/CIP1 was induced in wild-type p53-containing cells by exposure to DNA damaging agents, but not in mutant p53-containing cells. The induction of WAF1/CIP1 protein occurred in cells undergoing either p53-associated G1 arrest or apoptosis but not in cells induced to arrest in G1 or to undergo apoptosis through p53-independent mechanisms. DNA damage led to increased levels of WAF1/CIP1 in cyclin E-containing complexes and to an associated decrease in cyclin-dependent kinase activity. These results support the idea that WAF1/CIP1 is a critical downstream effector in the p53-specific pathway of growth control in mammalian cells.
Assuntos
Apoptose/fisiologia , Ciclinas/biossíntese , Fase G1/fisiologia , Inibidores de Proteínas Quinases , Proteína Supressora de Tumor p53/fisiologia , Alelos , Animais , Núcleo Celular/fisiologia , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/genética , Ciclinas/metabolismo , Dano ao DNA , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Genes p53/genética , Genes p53/fisiologia , Humanos , Linfoma de Células T/genética , Linfoma de Células T/patologia , Camundongos , Mutação/genética , Proteínas Quinases/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/biossínteseRESUMO
A public database, SAGEmap, was created as a component of the Cancer Genome Anatomy Project to provide a central location for depositing, retrieving, and analyzing human gene expression data. This database uses serial analysis of gene expression to quantify transcript levels in both malignant and normal human tissues. By accessing SAGEmap (http://www.ncbi.nlm.nih.gov/SAGE) the user can compare transcript populations between any of the posted libraries. As an initial demonstration of the database's utility, gene expression in human glioblastomas was compared with that of normal brain white matter. Of the 47,174 unique transcripts expressed in these two tissues, 471 (1.0%) were differentially expressed by more than 5-fold (P<0.001). Classification of these genes revealed functions consistent with the biological properties of glioblastomas, in particular: angiogenesis, transcription, and cell cycle related genes.
Assuntos
Bases de Dados Factuais , Expressão Gênica , Neoplasias/genética , Encéfalo/metabolismo , Clonagem Molecular , Glioblastoma/genética , Humanos , Internet , Modelos Teóricos , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Distribuição TecidualRESUMO
To begin to identify new tumor markers, we recently performed a systematic study of gene expression in cancers of the colon and pancreas. Of the 45,000 genes identified, 183 were found to be expressed at significantly elevated levels in pancreatic cancer. One of the genes was tissue inhibitor of metalloproteinase type I (TIMP-1), which encodes a secreted protein. Analysis of TIMP-1 serum levels revealed significant increases in pancreatic cancer patients, but TIMP-1 by itself was inadequate as a serum marker for cancer. However, a combination of individually suboptimal markers (TIMP-1, CA19-9, and carcinoembryonic antigen) detected 60% of 85 patients with pancreatic cancers in a highly specific manner. These results suggest that a systematic analysis of gene expression can reveal novel serum markers and that individually suboptimal markers can be combined to yield higher sensitivity and specificity.
Assuntos
Biomarcadores Tumorais/sangue , Expressão Gênica , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/diagnóstico , Inibidor Tecidual de Metaloproteinase-1/sangue , Northern Blotting , Antígeno CA-19-9/sangue , Antígeno Carcinoembrionário/sangue , Ensaio de Imunoadsorção Enzimática , Humanos , Neoplasias Pancreáticas/genética , Sensibilidade e Especificidade , Inibidor Tecidual de Metaloproteinase-1/genéticaAssuntos
Biomarcadores Tumorais/genética , Leucemia Linfocítica Crônica de Células B/enzimologia , Leucemia Linfocítica Crônica de Células B/genética , Mutação/genética , Proteínas Quinases/genética , DNA de Neoplasias/genética , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
The 300-kDa mannose 6-phosphate receptor cycles between the trans Golgi network and late endosomes, and between the plasma membrane and early endosomes, to deliver lysosomal enzymes to prelysosomes. Mannose 6-phosphate receptor trafficking requires structural determinants present in the cytoplasmic domain. However, when this domain was joined with the extracellular and transmembrane domains of the epidermal growth factor receptor, it was not sufficient to direct this chimera to late endosomes and the trans Golgi network (Dintzis, S. M., and Pfeffer, S. R. (1990) EMBO J. 9, 77-84). These findings suggested a role for extracellular and/or transmembrane domains in mannose 6-phosphate receptor trafficking. We describe here the construction and expression of chimeric receptors comprised of mannose 6-phosphate receptor extracellular and transmembrane sequences joined with cytoplasmic domain sequences derived from the human epidermal growth factor receptor or the human low density lipoprotein receptor. The chimeras were stable proteins which were efficiently endocytosed and competent to bind a mannose 6-phosphate-containing ligand. Antibody binding assays and indirect immunofluorescence showed that the chimeras containing the mannose 6-phosphate receptor extracellular domain colocalized with mannose 6-phosphate receptors in intracellular compartments. These experiments suggest that the presence of the mannose 6-phosphate receptor extracellular domain may interfere with the rapid recycling of receptors from early endosomes to the cell surface and detain receptors within endosomes.