Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
1.
J Natl Compr Canc Netw ; 22(3): 158-166, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38626807

RESUMO

BACKGROUND: Pancreatic adenocarcinoma (PC) is a highly lethal malignancy with a survival rate of only 12%. Surveillance is recommended for high-risk individuals (HRIs), but it is not widely adopted. To address this unmet clinical need and drive early diagnosis research, we established the Pancreatic Cancer Early Detection (PRECEDE) Consortium. METHODS: PRECEDE is a multi-institutional international collaboration that has undertaken an observational prospective cohort study. Individuals (aged 18-90 years) are enrolled into 1 of 7 cohorts based on family history and pathogenic germline variant (PGV) status. From April 1, 2020, to November 21, 2022, a total of 3,402 participants were enrolled in 1 of 7 study cohorts, with 1,759 (51.7%) meeting criteria for the highest-risk cohort (Cohort 1). Cohort 1 HRIs underwent germline testing and pancreas imaging by MRI/MR-cholangiopancreatography or endoscopic ultrasound. RESULTS: A total of 1,400 participants in Cohort 1 (79.6%) had completed baseline imaging and were subclassified into 3 groups based on familial PC (FPC; n=670), a PGV and FPC (PGV+/FPC+; n=115), and a PGV with a pedigree that does not meet FPC criteria (PGV+/FPC-; n=615). One HRI was diagnosed with stage IIB PC on study entry, and 35.1% of HRIs harbored pancreatic cysts. Increasing age (odds ratio, 1.05; P<.001) and FPC group assignment (odds ratio, 1.57; P<.001; relative to PGV+/FPC-) were independent predictors of harboring a pancreatic cyst. CONCLUSIONS: PRECEDE provides infrastructure support to increase access to clinical surveillance for HRIs worldwide, while aiming to drive early PC detection advancements through longitudinal standardized clinical data, imaging, and biospecimen captures. Increased cyst prevalence in HRIs with FPC suggests that FPC may infer distinct biological processes. To enable the development of PC surveillance approaches better tailored to risk category, we recommend adoption of subclassification of HRIs into FPC, PGV+/FPC+, and PGV+/FPC- risk groups by surveillance protocols.


Assuntos
Adenocarcinoma , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/epidemiologia , Detecção Precoce de Câncer/métodos , Estudos Prospectivos , Predisposição Genética para Doença , Imageamento por Ressonância Magnética
2.
Fam Cancer ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38436765

RESUMO

In the early years of my GI fellowship, a healthy 40-year-old man came to my clinic and announced that he was going to die of pancreatic cancer. His brothers, father and uncles had all died of the disease; he felt his fate was inescapable. I asked whether his family members had seen doctors or had any tests. His answer was yes to both. Even so, doctors could not diagnose the pancreatic cancer at early stages. CT scans were always negative. I thought to myself, in order to help this patient-CT scans may not be reliable for early detection. Perhaps other methods of imaging the pancreas might be of more benefit. This patient opened a door that led to a 30-year journey of trying to detect pancreatic cancer at earlier stages when it is curable.

3.
Pancreas ; 51(7): 790-799, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36395405

RESUMO

OBJECTIVES: Extracellular vesicles (EVs) are lipid bound vesicles secreted by cells into the extracellular environment. Studies have implicated EVs in cell proliferation, epithelial-mesenchymal transition, metastasis, angiogenesis, and mediating the interaction of tumor cells and microenvironment. A systematic characterization of EVs from pancreatic cancer cells and cancer-associated fibroblasts (CAFs) would be valuable for studying the roles of EV proteins in pancreatic tumorigenesis. METHODS: Proteomic and functional analyses were applied to characterize the proteomes of EVs released from 5 pancreatic cancer lines, 2 CAF cell lines, and a normal pancreatic epithelial cell line (HPDE). RESULTS: More than 1400 nonredundant proteins were identified in each EV derived from the cell lines. The majority of the proteins identified in the EVs from the cancer cells, CAFs, and HPDE were detected in all 3 groups, highly enriched in the biological processes of vesicle-mediated transport and exocytosis. Protein networks relevant to pancreatic tumorigenesis, including epithelial-mesenchymal transition, complement, and coagulation components, were significantly enriched in the EVs from cancer cells or CAFs. CONCLUSIONS: These findings support the roles of EVs as a potential mediator in transmitting epithelial-mesenchymal transition signals and complement response in the tumor microenvironment and possibly contributing to coagulation defects related to cancer development.


Assuntos
Fibroblastos Associados a Câncer , Vesículas Extracelulares , Neoplasias Pancreáticas , Humanos , Proteoma/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Proteômica , Vesículas Extracelulares/metabolismo , Vesículas Extracelulares/patologia , Neoplasias Pancreáticas/patologia , Transformação Celular Neoplásica/metabolismo , Microambiente Tumoral , Neoplasias Pancreáticas
4.
Cancer Lett ; 549: 215915, 2022 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-36113636

RESUMO

Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial homolog of HSP90 chaperones. It plays an important role in protection against oxidative stress and apoptosis by regulating reactive oxidative species (ROS). To further elucidate the mechanistic role of TRAP1 in regulating tumor cell survival, we used gamitrinib-triphenylphosphonium (G-TPP) to inhibit TRAP1 signaling pathways in colon cancer. Inhibition of TRAP1 by G-TPP disrupted redox homeostasis and induced cell death. However, colon cancers show a wide range of responses to G-TPP treatment through the induction of variable ER stress responses and ROS accumulation. Interestingly, a strong inverse correlation was observed between the expression of TRAP1 and antioxidant genes in colon tumor tissues using the GSE106582 database. Using a luciferase reporter assay, we detected increased transcriptional activation of antioxidant response elements (AREs) in G-TPP-treated DLD1 and RKO cells but not in SW48 cells. We found that G-TPP induced upregulation of GRP78, CHOP and PARP cleavage in G-TPP-sensitive cells (SW48). In contrast, G-TPP treatment of G-TPP-resistant cells (DLD1 and RKO) resulted in excessive activation of the antioxidant gene NRF2, leading to ROS detoxification and improved cell survival. The NRF2 target genes HO1 and NQO1 were upregulated in G-TPP-treated DLD1 cells, making the cells more resistant to G-TPP treatment. Furthermore, treatment with both a NRF2 inhibitor and a TRAP1 inhibitor led to excessive ROS production and exacerbated G-TPP-induced cell death in G-TPP-resistant cells. Taken together, dual targeting of TRAP1 and NRF2 may potentially overcome colon cancer resistance by raising cellular ROS levels above the cytotoxic threshold.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Antioxidantes , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Compostos Macrocíclicos , Fator 2 Relacionado a NF-E2/genética , Inibidores de Poli(ADP-Ribose) Polimerases , Espécies Reativas de Oxigênio , Receptores do Fator de Necrose Tumoral , Compostos de Terfenil
6.
Proc Natl Acad Sci U S A ; 118(31)2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34330826

RESUMO

Polyguanine tracts (PolyGs) are short guanine homopolymer repeats that are prone to accumulating mutations when cells divide. This feature makes them especially suitable for cell lineage tracing, which has been exploited to detect and characterize precancerous and cancerous somatic evolution. PolyG genotyping, however, is challenging because of the inherent biochemical difficulties in amplifying and sequencing repetitive regions. To overcome this limitation, we developed PolyG-DS, a next-generation sequencing (NGS) method that combines the error-correction capabilities of duplex sequencing (DS) with enrichment of PolyG loci using CRISPR-Cas9-targeted genomic fragmentation. PolyG-DS markedly reduces technical artifacts by comparing the sequences derived from the complementary strands of each original DNA molecule. We demonstrate that PolyG-DS genotyping is accurate, reproducible, and highly sensitive, enabling the detection of low-frequency alleles (<0.01) in spike-in samples using a panel of only 19 PolyG markers. PolyG-DS replicated prior results based on PolyG fragment length analysis by capillary electrophoresis, and exhibited higher sensitivity for identifying clonal expansions in the nondysplastic colon of patients with ulcerative colitis. We illustrate the utility of this method for resolving the phylogenetic relationship among precancerous lesions in ulcerative colitis and for tracing the metastatic dissemination of ovarian cancer. PolyG-DS enables the study of tumor evolution without prior knowledge of tumor driver mutations and provides a tool to perform cost-effective and easily scalable ultra-accurate NGS-based PolyG genotyping for multiple applications in biology, genetics, and cancer research.


Assuntos
Linhagem da Célula , DNA/genética , Guanina/química , Neoplasias/genética , Poli G/genética , Diferenciação Celular , Evolução Clonal , DNA/química , Genótipo , Humanos
7.
Biochimie ; 181: 25-33, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33242496

RESUMO

Modified DNA aptamers incorporated with amino-acid like side chains or drug-like ligands can offer unique advantages and enhance specificity as affinity ligands. Thy-1 membrane glycoprotein (THY1 or CD90) was previously identified as a biomarker candidate of neovasculature in pancreatic ductal adenocarcinoma (PDAC). The current study developed and evaluated modified DNA X-aptamers targeting THY1 in PDAC. The expression and glycosylation of THY1 in PDAC tumor tissues were assessed using immunohistochemistry and quantitative proteomics. Bead-based X-aptamer library that contains 108 different sequences was used to screen for high affinity THY1 X-aptamers. The sequences of the X-aptamers were analyzed with the next-generation sequencing. The affinities of the selected X-aptamers to THY1 were quantitatively evaluated with flow cytometry. Three high affinity THY1 X-aptamers, including XA-B217, XA-B216 and XA-A9, were selected after library screening and affinity binding evaluation. These three X-aptamers demonstrated a high binding affinity and specificity to THY1 protein and the THY1 expressing cell lines, using THY1 antibody as a comparison. The development of these X-aptamers provides highly specific and non-immunogenic affinity ligands for THY1 binding in the context of biomarker development and clinical applications. They could be further exploited to assist molecular imaging of PDAC targeting THY1.


Assuntos
Aptâmeros de Nucleotídeos , Carcinoma Ductal Pancreático , Sistemas de Liberação de Medicamentos , Proteínas de Neoplasias , Neoplasias Pancreáticas , Antígenos Thy-1 , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Humanos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Antígenos Thy-1/antagonistas & inibidores , Antígenos Thy-1/metabolismo
8.
Cancers (Basel) ; 12(6)2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32545216

RESUMO

BACKGROUND: Diabetes is a risk factor associated with pancreatic ductal adenocarcinoma (PDAC), and new adult-onset diabetes can be an early sign of pancreatic malignancy. Development of blood-based biomarkers to identify diabetic patients who warrant imaging tests for cancer detection may represent a realistic approach to facilitate earlier diagnosis of PDAC in a risk population. METHODS: A spectral library-based proteomic platform was applied to interrogate biomarker candidates in plasma samples from clinically well-defined diabetic cohorts with and without PDAC. Random forest algorithm was used for prediction model building and receiver operating characteristic (ROC) curve analysis was applied to evaluate the prediction probability of potential biomarker panels. RESULTS: Several biomarker panels were cross-validated in the context of detection of PDAC within a diabetic background. In combination with carbohydrate antigen 19-9 (CA19-9), the panel, which consisted of apolipoprotein A-IV (APOA4), monocyte differentiation antigen CD14 (CD14), tetranectin (CLEC3B), gelsolin (GSN), histidine-rich glycoprotein (HRG), inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3), plasma kallikrein (KLKB1), leucine-rich alpha-2-glycoprotein (LRG1), pigment epithelium-derived factor (SERPINF1), plasma protease C1 inhibitor (SERPING1), and metalloproteinase inhibitor 1 (TIMP1), demonstrated an area under curve (AUC) of 0.85 and a two-fold increase in detection accuracy compared to CA19-9 alone. The study further evaluated the correlations of protein candidates and their influences on the performance of biomarker panels. CONCLUSIONS: Proteomics-based multiplex biomarker panels improved the detection accuracy for diagnosis of early stage PDAC in diabetic patients.

9.
Cancer Lett ; 469: 429-436, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31734355

RESUMO

Proteins are the essential functional biomolecules profoundly implicated in all aspects of pancreatic tumorigenesis and its progression. While common genomic factors, such as KRAS, TP53, SMAD4, and CDKN2A have been well recognized in association of pancreatic ductal adenocarcinoma (PDAC), our understanding of functional changes at the proteome level merits further investigation. Malignance associated proteome alterations can be attributed to the convoluted outcomes from genetic, epigenetic and environmental factors in initiating and progressing PDAC, and may reflect on changes in protein expressional level, structure, localization, as well as post-translational modifications (PTMs) status. The study of localized or systemic proteome alterations in PDAC, as well as its precursor lesions, such as pancreatic intraepithelial neoplasia (PanIN) and mucinous pancreatic cystic neoplasm, would provide unique perspectives in elucidating functional molecular events underlying PDAC. While efforts have been made, challenges still exist to comprehensively integrate much of the proteomic discovery to the perspectives gained from genomic studies in the context of biomarker discovery. Novel approaches and data from well-defined longitudinal clinical studies and experimental models are needed to facilitate the study of PDAC and precursor lesions for early detection and intervention.


Assuntos
Adenocarcinoma/genética , Biomarcadores Tumorais/genética , Carcinoma Ductal Pancreático/genética , Proteoma/genética , Adenocarcinoma/patologia , Carcinogênese/genética , Carcinoma Ductal Pancreático/patologia , Progressão da Doença , Humanos , Mutação , Proteínas de Neoplasias/genética , Processamento de Proteína Pós-Traducional/genética , Proteômica
10.
Clin Proteomics ; 16: 31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31346328

RESUMO

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer that is characterized by its poor prognosis, rapid progression and development of drug resistance. Chemotherapy is a vital treatment option for most of PDAC patients. Stratification of PDAC patients, who would have a higher likelihood of responding to chemotherapy, could facilitate treatment selection and patient management. METHODS: A quantitative proteomic study was performed to characterize the protein profiles in the plasma of PDAC patients undergoing chemotherapy to determine if specific biomarkers could be used to predict likelihood of therapeutic response. RESULTS: By comparing the plasma proteome of the PDAC patients with positive therapeutic response and longer overall survival (Good-responders) to those who did not respond as well with shorter survival time (Limited-responders), we identified differential proteins and protein variants that could effectively segregate Good-responders from Limited-responders. Functional clustering and pathway analysis further suggested that many of these differential proteins were involved in pancreatic tumorigenesis. Four proteins, including vitamin-K dependent protein Z (PZ), sex hormone-binding globulin (SHBG), von Willebrand factor (VWF) and zinc-alpha-2-glycoprotein (AZGP1), were further evaluated as single or composite predictive biomarker with/without inclusion of CA 19-9. A composite biomarker panel that consists of PZ, SHBG, VWF and CA 19-9 demonstrated the best performance in distinguishing Good-responders from Limited-responders. CONCLUSION: Based on the cohort investigated, our data suggested that systemic proteome alterations involved in pathways associated with inflammation, immunoresponse, coagulation and complement cascades may be reporters of chemo-treatment outcome in PDAC patients. For the majority of the patients involved, the panel consisting of PZ, SHBG, VWF and CA 19-9 was able to segregate Good-responders from Limited-responders effectively. Our data also showed that dramatic fluctuations of biomarker concentration in the circulating system of a PDAC patient, which might result from biological heterogeneity or confounding complications, could diminish the performance of a biomarker. Categorization of PDAC patients in terms of their tumor stages and histological types could potentially facilitate patient stratification for treatment.

11.
Mol Cancer Res ; 17(2): 488-498, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30446624

RESUMO

The role of mitochondrial DNA (mtDNA) mutations in cancer remains controversial. Ulcerative colitis is an inflammatory bowel disease that increases the risk of colorectal cancer and involves mitochondrial dysfunction, making it an ideal model to study the role of mtDNA in tumorigenesis. Our goal was to comprehensively characterize mtDNA mutations in ulcerative colitis tumorigenesis using Duplex Sequencing, an ultra-accurate next-generation sequencing method. We analyzed 46 colon biopsies from non-ulcerative colitis control patients and ulcerative colitis patients with and without cancer, including biopsies at all stages of dysplastic progression. mtDNA was sequenced at a median depth of 1,364x. Mutations were classified by mutant allele frequency: clonal > 0.95, subclonal 0.01-0.95, and very low frequency (VLF) < 0.01. We identified 208 clonal and subclonal mutations and 56,764 VLF mutations. Mutations were randomly distributed across the mitochondrial genome. Clonal and subclonal mutations increased in number and pathogenicity in early dysplasia, but decreased in number and pathogenicity in cancer. Most clonal, subclonal, and VLF mutations were C>T transitions in the heavy strand of mtDNA, which likely arise from DNA replication errors. A subset of VLF mutations were C>A transversions, which are probably due to oxidative damage. VLF transitions and indels were less abundant in the non-D-loop region and decreased with progression. Our results indicate that mtDNA mutations are frequent in ulcerative colitis preneoplasia but negatively selected in cancers. IMPLICATIONS: While mtDNA mutations might contribute to early ulcerative colitis tumorigenesis, they appear to be selected against in cancer, suggesting that functional mitochondria might be required for malignant transformation in ulcerative colitis.


Assuntos
Colite Ulcerativa/genética , DNA Mitocondrial/genética , Mutação , Lesões Pré-Cancerosas/genética , Colite Ulcerativa/patologia , Progressão da Doença , Feminino , Humanos , Masculino , Neoplasias/genética , Neoplasias/patologia , Lesões Pré-Cancerosas/patologia
12.
Cell Rep ; 23(9): 2819-2831.e5, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29847809

RESUMO

Cancer is mostly incurable when diagnosed at a metastatic stage, making its early detection via blood proteins of immense clinical interest. Proteomic changes in tumor tissue may lead to changes detectable in the protein composition of circulating blood plasma. Using a proteomic workflow combining N-glycosite enrichment and SWATH mass spectrometry, we generate a data resource of 284 blood samples derived from patients with different types of localized-stage carcinomas and from matched controls. We observe whether the changes in the patient's plasma are specific to a particular carcinoma or represent a generic signature of proteins modified uniformly in a common, systemic response to many cancers. A quantitative comparison of the resulting N-glycosite profiles discovers that proteins related to blood platelets are common to several cancers (e.g., THBS1), whereas others are highly cancer-type specific. Available proteomics data, including a SWATH library to study N-glycoproteins, will facilitate follow-up biomarker research into early cancer detection.


Assuntos
Carcinoma/sangue , Carcinoma/patologia , Glicoproteínas/sangue , Espectrometria de Massas/métodos , Algoritmos , Plaquetas/metabolismo , Carcinoma/genética , Estudos de Coortes , Humanos , Estadiamento de Neoplasias , Oncogenes , Proteoma/metabolismo , Curva ROC
13.
Carcinogenesis ; 39(1): 11-20, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29087436

RESUMO

Cumulative evidence indicates that a significant proportion of cancer evolution may occur before the development of histological abnormalities. While recent improvements in DNA sequencing technology have begun to reveal the presence of these early preneoplastic clones, the concept of 'premalignant field' was already introduced by Slaughter more than half a century ago. Also referred to as 'field effect', 'field defect' or 'field cancerization', these terms describe the phenomenon by which molecular alterations develop in normal-appearing tissue and expand to form premalignant patches with the potential to progress to dysplasia and cancer. Field effects have been well-characterized in ulcerative colitis, an inflammatory bowel disease that increases the risk of colorectal cancer. The study of the molecular alterations that define these fields is informative of mechanisms of tumor initiation and progression and has provided potential targets for early cancer detection. Herein, we summarize the current knowledge about the molecular alterations that comprise the field effect in ulcerative colitis and the clinical utility of these fields for cancer screening and prevention.


Assuntos
Colite Ulcerativa/complicações , Neoplasias Colorretais , Lesões Pré-Cancerosas , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Neoplasias Colorretais/etiologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Humanos , Lesões Pré-Cancerosas/etiologia , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia
14.
Sci Rep ; 7(1): 7950, 2017 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-28801576

RESUMO

Pancreatic cancer is a lethal disease with poor prognosis. Gemcitabine has been the first line systemic treatment for pancreatic cancer. However, the rapid development of drug resistance has been a major hurdle in gemcitabine therapy leading to unsatisfactory patient outcomes. With the recent renewed understanding of glutamine metabolism involvement in drug resistance and immuno-response, we investigated the anti-tumor effect of a glutamine analog (6-diazo-5-oxo-L-norleucine) as an adjuvant treatment to sensitize chemoresistant pancreatic cancer cells. We demonstrate that disruption of glutamine metabolic pathways improves the efficacy of gemcitabine treatment. Such a disruption induces a cascade of events which impacts glycan biosynthesis through Hexosamine Biosynthesis Pathway (HBP), as well as cellular redox homeostasis, resulting in global changes in protein glycosylation, expression and functional effects. The proteome alterations induced in the resistant cancer cells and the secreted exosomes are intricately associated with the reduction in cell proliferation and the enhancement of cancer cell chemosensitivity. Proteins associated with EGFR signaling, including downstream AKT-mTOR pathways, MAPK pathway, as well as redox enzymes were downregulated in response to disruption of glutamine metabolic pathways.


Assuntos
Desoxicitidina/análogos & derivados , Diazo-Oxo-Norleucina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glutamina/metabolismo , Neoplasias Pancreáticas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/farmacologia , Sinergismo Farmacológico , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Proteômica/métodos , Gencitabina
15.
Proteomics Clin Appl ; 11(9-10)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28627758

RESUMO

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease characterized by its late diagnosis, poor prognosis and rapid development of drug resistance. Using the data-independent acquisition (DIA) technique, the authors applied a spectral library-based proteomic approach to analyze N-glycosylated peptides in human plasma, in the context of pancreatic cancer study. EXPERIMENTAL DESIGN: The authors extended the application of DIA to the quantification of N-glycosylated peptides enriched from plasma specimens from a clinically well-defined cohort that consists of patients with early stage PDAC, chronic pancreatitis and healthy subjects. RESULTS: The analytical platform was evaluated in light of its robustness for quantitative analysis of large-scale clinical specimens. The authors analysis indicated that the level of N-glycosylated peptides derived from galectin-3 binding proteins (LGALS3BP) were frequently elevated in plasma from PDAC patients, concurrent with the altered N-glycosylation of LGALS3BP observed in the tumor tissue. CONCLUSION AND CLINICAL RELEVANCE: The glycosylation form of LGALS3BP influences its function in the galectin network, which profoundly involves in cancer progression, immune response and drug resistance. As one of the major binding ligands of galectin network, discovery of site specific N-glycosylation changes of LGALS3BP in association of PDAC may provide useful clues to facilitate cancer detection or phenotype stratification.


Assuntos
Antígenos de Neoplasias/sangue , Biomarcadores Tumorais/sangue , Proteínas de Transporte/sangue , Glicoproteínas/sangue , Neoplasias Pancreáticas/sangue , Biblioteca de Peptídeos , Proteômica , Adenocarcinoma/sangue , Adenocarcinoma/diagnóstico , Glicosilação , Humanos , Neoplasias Pancreáticas/diagnóstico
16.
Gut ; 66(5): 852-862, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28389570

RESUMO

OBJECTIVE: Blood vessel epicardial substance (BVES) is a tight junction-associated protein that regulates epithelial-mesenchymal states and is underexpressed in epithelial malignancy. However, the functional impact of BVES loss on tumourigenesis is unknown. Here we define the in vivo role of BVES in colitis-associated cancer (CAC), its cellular function and its relevance to patients with IBD. DESIGN: We determined BVES promoter methylation status using an Infinium HumanMethylation450 array screen of patients with UC with and without CAC. We also measured BVES mRNA levels in a tissue microarray consisting of normal colons and CAC samples. Bves-/- and wild-type mice (controls) were administered azoxymethane (AOM) and dextran sodium sulfate (DSS) to induce tumour formation. Last, we used a yeast two-hybrid screen to identify BVES interactors and performed mechanistic studies in multiple cell lines to define how BVES reduces c-Myc levels. RESULTS: BVES mRNA was reduced in tumours from patients with CAC via promoter hypermethylation. Importantly, BVES promoter hypermethylation was concurrently present in distant non-malignant-appearing mucosa. As seen in human patients, Bves was underexpressed in experimental inflammatory carcinogenesis, and Bves-/- mice had increased tumour multiplicity and degree of dysplasia after AOM/DSS administration. Molecular analysis of Bves-/- tumours revealed Wnt activation and increased c-Myc levels. Mechanistically, we identified a new signalling pathway whereby BVES interacts with PR61α, a protein phosphatase 2A regulatory subunit, to mediate c-Myc destruction. CONCLUSION: Loss of BVES promotes inflammatory tumourigenesis through dysregulation of Wnt signalling and the oncogene c-Myc. BVES promoter methylation status may serve as a CAC biomarker.


Assuntos
Carcinogênese/genética , Moléculas de Adesão Celular/genética , Colite Ulcerativa/metabolismo , Neoplasias do Colo/metabolismo , Proteínas de Membrana/genética , Proteínas Musculares/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Animais , Biomarcadores Tumorais/genética , Células CACO-2 , Colite/induzido quimicamente , Colite/genética , Colite/metabolismo , Colite Ulcerativa/genética , Colo/metabolismo , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Metilação de DNA , Sulfato de Dextrana , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Knockout , Regiões Promotoras Genéticas , Proteína Fosfatase 2/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , RNA Mensageiro/metabolismo , Via de Sinalização Wnt
17.
J Proteome Res ; 16(2): 665-676, 2017 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-27995795

RESUMO

The advent of high-resolution and frequency mass spectrometry has ushered in an era of data-independent acquisition (DIA). This approach affords enormous multiplexing capacity and is particularly suitable for clinical biomarker studies. However, DIA-based quantification of clinical plasma samples is a daunting task due to the high complexity of clinical plasma samples, the diversity of peptides within the samples, and the high biologic dynamic range of plasma proteins. Here we applied DIA methodology, including a highly reproducible sample preparation and LC-MS/MS analysis, and assessed its utility for clinical plasma biomarker detection. A pancreatic cancer-relevant plasma spectral library was constructed consisting of over 14 000 confidently identified peptides derived from over 2300 plasma proteins. Using a nonhuman protein as the internal standard, various empirical parameters were explored to maximize the reliability and reproducibility of the DIA quantification. The DIA parameters were optimized based on the quantification cycle times and fragmentation profile complexity. Higher analytical and biological reproducibility was recorded for the tryptic peptides without labile residues and missed cleavages. Quantification reliability was developed for the peptides identified within a consistent retention time and signal intensity. Linear analytical dynamic range and the lower limit of quantification were assessed, suggesting the critical role of sample complexity in optimizing DIA settings. Technical validation of the assay using a cohort of clinical plasma indicated the robustness and unique advantage for targeted analysis of clinical plasma samples in the context of biomarker development.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Pancreáticas/sangue , Peptídeos/sangue , Proteômica , Cromatografia Líquida , Humanos , Espectrometria de Massas em Tandem
18.
World J Gastroenterol ; 22(42): 9288-9299, 2016 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-27895417

RESUMO

Aberrations in protein glycosylation and polysaccharides play a pivotal role in pancreatic tumorigenesis, influencing cancer progression, metastasis, immuno-response and chemoresistance. Abnormal expression in sugar moieties can impact the function of various glycoproteins, including mucins, surface receptors, adhesive proteins, proteoglycans, as well as their effectors and binding ligands, resulting in an increase in pancreatic cancer invasiveness and a cancer-favored microenvironment. Recent advance in glycoproteomics, glycomics and other chemical biology techniques have been employed to better understand the complex mechanism of glycosylation events and how they orchestrate molecular activities in genomics, proteomics and metabolomics implicated in pancreatic adenocarcinoma. A variety of strategies have been demonstrated targeting protein glycosylation and polysaccharides for diagnostic and therapeutic development.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Glicômica/métodos , Glicoproteínas/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteômica/métodos , Animais , Antineoplásicos/uso terapêutico , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Descoberta de Drogas/métodos , Glicosilação , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Valor Preditivo dos Testes , Prognóstico , Processamento de Proteína Pós-Traducional
19.
World J Gastroenterol ; 22(35): 7882-91, 2016 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-27672285

RESUMO

Patients with extensive ulcerative colitis (UC) of more than eight years duration have an increased risk of colorectal cancer. Molecular biomarkers for dysplasia and cancer could have a great clinical value in managing cancer risk in these UC patients. Using a wide range of molecular techniques - including cutting-edge OMICS technologies - recent studies have identified clinically relevant biomarker candidates from a variety of biosamples, including colonic biopsies, blood, stool, and urine. While the challenge remains to validate these candidate biomarkers in multi-center studies and with larger patient cohorts, it is certain that accurate biomarkers of colitis-associated neoplasia would improve clinical management of neoplastic risk in UC patients. This review highlights the ongoing avenues of research in biomarker development for colitis-associated colorectal cancer.


Assuntos
Biomarcadores Tumorais/análise , Colite Ulcerativa/diagnóstico , Neoplasias Colorretais/diagnóstico , Biópsia , Colite Ulcerativa/patologia , Neoplasias Colorretais/patologia , Metilação de DNA , Progressão da Doença , Humanos , MicroRNAs/análise , Lesões Pré-Cancerosas/patologia , Fatores de Risco
20.
Pancreas ; 45(8): 1080-91, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27518363

RESUMO

Pancreatic cancer is the fourth leading cause of cancer related deaths in the United States with a 5-year survival rate of less than 10%. The Division of Cancer Prevention of the National Cancer Institute sponsored the Pancreatic Cancer Chemoprevention Translational Workshop on September 10 to 11, 2015. The goal of the workshop was to obtain information regarding the current state of the science and future scientific areas that should be prioritized for pancreatic cancer prevention research, including early detection and intervention for high-risk precancerous lesions. The workshop addressed the molecular/genetic landscape of pancreatic cancer and precursor lesions, high-risk populations and criteria to identify a high-risk population for potential chemoprevention trials, identification of chemopreventative/immunopreventative agents, and use of potential biomarkers and imaging for assessing short-term efficacy of a preventative agent. The field of chemoprevention for pancreatic cancer is emerging, and this workshop was organized to begin to address these important issues and promote multi-institutional efforts in this area. The meeting participants recommended the development of an National Cancer Institute working group to coordinate efforts, provide a framework, and identify opportunities for chemoprevention of pancreatic cancer.


Assuntos
Neoplasias Pancreáticas , Biomarcadores , Quimioprevenção , Previsões , Humanos , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA