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1.
Cancer Lett ; 568: 216286, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37354984

RESUMO

Pancreatic cancer (PC) is a deadly cancer with a high mortality rate. The unique characteristics of PC, including desmoplasia and immunosuppression, have made it difficult to develop effective treatment strategies. Pancreatic stellate cells (PSCs) play a crucial role in the progression of the disease by interacting with cancer cells. One of the key mediators of PSC - cancer cell interactions is the hepatocyte growth factor (HGF)/c-MET pathway. Using an immunocompetent in vivo model of PC as well as in vitro experiments, this study has shown that a combined approach using HGF/c-MET inhibitors to target stromal-tumour interactions and chemotherapy (gemcitabine) to target cancer cells effectively decreases tumour volume, EMT, and stemness, and importantly, eliminates metastasis. Notably, HGF/c-MET inhibition decreases TGF-ß secretion by cancer cells, resulting in an increase in cytotoxic T-cell infiltration, thus contributing to cancer cell death in tumours. HGF/c-MET inhibition + chemotherapy was also found to normalise the gut microbiome and improve gut microbial diversity. These findings provide a strong platform for assessment of this triple therapy (HGF/c-MET inhibition + chemotherapy) approach in the clinical setting.


Assuntos
Fator de Crescimento de Hepatócito , Neoplasias Pancreáticas , Humanos , Fator de Crescimento de Hepatócito/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Linhagem Celular Tumoral , Neoplasias Pancreáticas/patologia , Linfócitos T/metabolismo , Neoplasias Pancreáticas
2.
Cancers (Basel) ; 13(20)2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34680372

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is a devastating condition characterised by vague symptomatology and delayed diagnosis. About 30% of PDAC patients report a history of new onset diabetes, usually diagnosed within 3 years prior to the diagnosis of cancer. Thus, new onset diabetes, which is also known as pancreatic cancer-related diabetes (PCRD), could be a harbinger of PDAC. Diabetes is driven by progressive ß cell loss/dysfunction and insulin resistance, two key features that are also found in PCRD. Experimental studies suggest that PDAC cell-derived exosomes carry factors that are detrimental to ß cell function and insulin sensitivity. However, the role of stromal cells, particularly pancreatic stellate cells (PSCs), in the pathogenesis of PCRD is not known. PSCs are present around the earliest neoplastic lesions and around islets. Given that PSCs interact closely with cancer cells to drive cancer progression, it is possible that exosomal cargo from both cancer cells and PSCs plays a role in modulating ß cell function and peripheral insulin resistance. Identification of such mediators may help elucidate the mechanisms of PCRD and aid early detection of PDAC. This paper discusses the concept of a novel role of PSCs in the pathogenesis of PCRD.

3.
Cancers (Basel) ; 13(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199452

RESUMO

BACKGROUND: Inhibition of hepatocyte growth factor (HGF)/c-MET pathway, a major mediator of pancreatic stellate cell (PSC)-PC cell interactions, retards local and distant cancer progression. This study examines the use of this treatment in preventing PC progression after resection. We further investigate the postulated existence of circulating PSCs (cPSCs) as a mediator of metastatic PC. METHODS: Two orthotopic PC mouse models, produced by implantation of a mixture of luciferase-tagged human pancreatic cancer cells (AsPC-1), and human PSCs were used. Model 1 mice underwent distal pancreatectomy 3-weeks post-implantation (n = 62). One-week post-resection, mice were randomised to four treatments of 8 weeks: (i) IgG, (ii) gemcitabine (G), (iii) HGF/c-MET inhibition (HiCi) and (iv) HiCi + G. Tumour burden was assessed longitudinally by bioluminescence. Circulating tumour cells and cPSCs were enriched by filtration. Tumours of Model 2 mice progressed for 8 weeks prior to the collection of primary tumour, metastases and blood for single-cell RNA-sequencing (scRNA-seq). RESULTS: HiCi treatments: (1) reduced both the risk and rate of disease progression after resection; (2) demonstrated an anti-angiogenic effect on immunohistochemistry; (3) reduced cPSC counts. cPSCs were identified using immunocytochemistry (α-smooth muscle actin+, pan-cytokeratin-, CD45-), and by specific PSC markers. scRNA-seq confirmed the existence of cPSCs and identified potential genes associated with development into cPSCs. CONCLUSIONS: This study is the first to demonstrate the efficacy of adjuvant HGF/c-Met inhibition for PC and provides the first confirmation of the existence of circulating PSCs.

4.
Pancreatology ; 21(1): 103-114, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33309014

RESUMO

BACKGROUND: The detection and quantification of circulating tumour cells (CTCs) in pancreatic cancer (PC) has the potential to provide prognostic information. The aim of this review was to provide an overview of the literature surrounding CTCs in PC. METHODS: A systematic literature review on CTCs in PC between 2005-2020 was performed. Data based on peripheral vein samples were used to determine the positivity rate of CTCs, their prognostic significance and their relative numbers compared to portal vein (PV) samples. RESULTS: The overall CTC detection rate in forty-four articles was 65% (95%CI: 55-75%). Detection rate for CellSearch was 26% (95%CI: 14-38%), which was lower than for both filtration and microfluidic techniques. In nine studies with >50 patients, overall survival was worse with CTC positivity (HR 1.82; 95%CI: 1.61-2.05). Five of seven studies which described PV CTC collection provided patient-level data. PV CTC yield was 7.7-fold (95%CI 1.35-43.9) that of peripheral blood. CONCLUSIONS: CTCs were detected in the peripheral circulation of most patients with PC and may be related to prognosis and disease stage. PV blood contains more CTCs than peripheral blood sampling. This review points to the maturation of techniques of CTC enrichment, and its evidence base for eventual clinical deployment.


Assuntos
Células Neoplásicas Circulantes/patologia , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/patologia , Humanos
5.
Int J Mol Sci ; 21(23)2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33271944

RESUMO

Pancreatic cancer (pancreatic ductal adenocarcinoma (PDAC/PC)) has been an aggressive disease that is associated with early metastases. It is characterized by dense and collagenous desmoplasia/stroma, predominantly produced by pancreatic stellate cells (PSCs). PSCs interact with cancer cells as well as other stromal cells, facilitating disease progression. A candidate growth factor pathway that may mediate this interaction is the hepatocyte growth factor (HGF)/c-MET pathway. HGF is produced by PSCs and its receptor c-MET is expressed on pancreatic cancer cells and endothelial cells. The current review discusses the role of the MET/HGF axis in tumour progression and dissemination of pancreatic cancer. Therapeutic approaches that were developed targeting either the ligand (HGF) or the receptor (c-MET) have not been shown to translate well into clinical settings. We discuss a two-pronged approach of targeting both the components of this pathway to interrupt the stromal-tumour interactions, which may represent a potential therapeutic strategy to improve outcomes in PC.


Assuntos
Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Neoplasias Pancreáticas/etiologia , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , Humanos , Estadiamento de Neoplasias , Neovascularização Patológica , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia , Transdução de Sinais , Microambiente Tumoral
6.
J Vis Exp ; (163)2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-33044459

RESUMO

There is a lack of satisfactory animal models to study adjuvant and/or neoadjuvant therapy in patients being considered for surgery of pancreatic cancer (PC). To address this deficiency, we describe a mouse model involving orthotopic implantation of PC followed by distal pancreatectomy and splenectomy. The model has been demonstrated to be safe and suitably flexible for the study of various therapeutic approaches in adjuvant and neo adjuvant settings. In this model, a pancreatic tumor is first generated by implanting a mixture of human pancreatic cancer cells (luciferase-tagged AsPC-1) and human cancer associated pancreatic stellate cells into the distal pancreas of Balb/c athymic nude mice. After three weeks, the cancer is resected by re-laparotomy, distal pancreatectomy and splenectomy. In this model, bioluminescence imaging can be used to follow the progress of cancer development and effects of resection/treatments. Following resection, adjuvant therapy can be given. Alternatively, neoadjuvant treatment can be given prior to resection. Representative data from 45 mice are presented. All mice underwent successful distal pancreatectomy/splenectomy with no issues of hemostasis. A macroscopic proximal pancreatic margin greater than 5 mm was achieved in 43 (96%) mice. The technical success rate of pancreatic resection was 100%, with 0% early mortality and morbidity. None of the animals died during the week after resection. In summary, we describe a robust and reproducible technique for a surgical resection model of pancreatic cancer in mice which mimics the clinical scenario. The model may be useful for the testing of both adjuvant and neoadjuvant treatments.


Assuntos
Neoplasias Pancreáticas/patologia , Animais , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Pancreatectomia , Neoplasias Pancreáticas/cirurgia , Baço/cirurgia
8.
Br J Cancer ; 122(10): 1486-1495, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32203220

RESUMO

BACKGROUND: Stromal-tumour interactions facilitate pancreatic cancer (PC) progression. The hepatocyte growth factor (HGF)/c-MET pathway is upregulated in PC and mediates the interaction between cancer cells and stromal pancreatic stellate cells (PSCs). This study assessed the effect of HGF/c-MET inhibition plus gemcitabine (G) on the progression of advanced PC. METHODS: Orthotopic PC was produced by implantation of luciferase-tagged human cancer cells + human PSCs into mouse pancreas. Tumours were allowed to develop without treatment for 4 weeks. Mice were then treated for 6 weeks with one of the following: IgG, G, HGF inhibitor (Hi), c-MET inhibitor (Ci), Hi + Ci, Hi + G, Ci + G, or Hi + Ci + G. RESULTS: Bioluminescence imaging showed similar tumour sizes in all mice at the initiation of treatments. Triple therapy (Hi + Ci + G): (1) completely eliminated metastasis; (2) significantly reduced tumour size as assessed by bioluminescence and at necropsy; (3) significantly reduced proliferating cancer cell density and stem cell marker DCLK1 expression in tumours. In vitro 3D culture studies supported our in vivo findings. CONCLUSION: Even at an advanced disease stage, a two-pronged approach, targeting (a) HGF/c-MET with relevant inhibitors and (b) cancer cells with chemotherapy, completely eliminated metastasis and significantly decreased tumour growth, suggesting that this is a promising treatment approach for PC.


Assuntos
Carcinogênese/efeitos dos fármacos , Fator de Crescimento de Hepatócito/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Animais , Carcinogênese/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Quinases Semelhantes a Duplacortina , Fator de Crescimento de Hepatócito/genética , Humanos , Imunoglobulina G/farmacologia , Camundongos , Metástase Neoplásica , Estadiamento de Neoplasias , Células-Tronco Neoplásicas , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/efeitos dos fármacos , Células Estreladas do Pâncreas/metabolismo , Proteínas Proto-Oncogênicas c-met/genética , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
9.
Pancreatology ; 20(3): 409-418, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31928917

RESUMO

Tumour-stromal interactions have now been acknowledged to play a major role in pancreatic cancer (PC) progression. The abundant collagenous stroma is produced by a specific cell type in the pancreas-the pancreatic stellate cell (PSC). Pancreatic stellate cells (PSCs) are a unique resident cell type of pancreas and with a critical role in both healthy and diseased pancreas. Accumulating evidence indicates that PSCs interact closely with cancer cells as well as with other cell types of the stroma such as immune cells, endothelial cells and neuronal cells, to set up a growth permissive microenvironment for pancreatic tumours, which facilitates local tumour growth as well as distant metastasis. Consequently, recent work in the field has focused on the development of novel therapeutic approaches targeting the stroma to inhibit PC progression. Such a multi-pronged approach targeting both tumour and stromal elements of PC has been successfully applied in pre-clinical settings. The challenge now is to translate the pre-clinical findings into the clinical setting to achieve better outcomes for pancreatic cancer patients.


Assuntos
Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/patologia , Progressão da Doença , Humanos , Microambiente Tumoral
10.
Oncotarget ; 8(44): 76722-76739, 2017 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-29100344

RESUMO

Stromal-tumor interactions in pancreatic cancer (PC) impact on treatment outcomes. Pancreatic stellate cells (PSCs) produce the collagenous stroma of PC and interact with cancer cells to facilitate disease progression. A candidate growth factor pathway that may mediate this interaction is the hepatocyte growth factor (HGF)/c-MET pathway. HGF is produced by PSCs and its receptor c-MET is expressed on pancreatic cancer cells. We studied the effects on PC progression of inhibiting the HGF/c-MET pathway in the presence and absence of a representative chemotherapeutic agent, gemcitabine. Using an orthotopic model of PC we have shown that "triple therapy" (inhibition of both HGF and c-MET combined with gemcitabine) resulted in the greatest reduction in tumor volume compared to each of the treatments alone or in dual combinations. Importantly, metastasis was virtually eliminated in mice receiving triple therapy. Our in vivo findings were supported by in vitro studies showing that the increase in cancer cell proliferation and migration in response to PSC secretions was significantly inhibited by the triple regimen. Our studies suggest that a combined approach, that targets tumor cells by chemotherapy while inhibiting specific pathways that mediate stromal-tumor interactions, may represent a novel therapeutic strategy to improve outcomes in PC.

11.
Carcinogenesis ; 38(6): 588-591, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28379317

RESUMO

Pancreatic stellate cells (PSCs) are known to play an important role in facilitating pancreatic cancer progression-both in terms of local tumour growth as well as the establishment of metastases. We have previously demonstrated that PSCs from the primary cancer seed to distant metastatic sites. We therefore hypothesise that PSCs circulate along with pancreatic cancer cells (circulating tumour cells-CTCs) to help create a growth permissive microenvironment at distant metastatic sites. This review aims to explore the concept of circulating PSCs in pancreatic cancer and suggests future directions for research in this area.


Assuntos
Células Neoplásicas Circulantes/patologia , Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/patologia , Microambiente Tumoral , Animais , Comunicação Celular , Humanos , Metástase Neoplásica , Células Estromais
12.
Br J Cancer ; 114(3): 269-80, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26766740

RESUMO

BACKGROUND: Pancreatic stellate cells (PSCs, which produce the stroma of pancreatic cancer (PC)) interact with cancer cells to facilitate PC growth. A candidate growth factor pathway that may mediate this interaction is the HGF-c-MET pathway. METHODS: Effects of HGF inhibition (using a neutralising antibody AMG102) alone or in combination with gemcitabine were assessed (i) in vivo using an orthotopic model of PC, and (ii) in vitro using cultured PC cells (AsPC-1) and human PSCs. RESULTS: We have shown that human PSCs (hPSCs) secrete HGF but do not express the receptor c-MET, which is present predominantly on cancer cells. HGF inhibition was as effective as standard chemotherapy in inhibiting local tumour growth but was significantly more effective than gemcitabine in reducing tumour angiogenesis and metastasis. HGF inhibition has resulted in reduced metastasis; however, interestingly this antimetastatic effect was lost when combined with gemcitabine. This suggests that gemcitabine treatment selects out a subpopulation of cancer cells with increased epithelial-mesenchymal transition (EMT) and stem-cell characteristics, as supported by our findings of increased expression of EMT and stem-cell markers in tumour sections from our animal model. In vitro studies showed that hPSC secretions induced proliferation and migration, but inhibited apoptosis, of cancer cells. These effects were countered by pretreatment of hPSC secretions with a HGF-neutralising antibody but not by gemcitabine, indicating a key role for HGF in PSC-PC interactions. CONCLUSIONS: Our studies suggest that targeted therapy to inhibit stromal-tumour interactions mediated by the HGF-c-MET pathway may represent a novel therapeutic approach in PC that will require careful modelling for optimal integration with existing treatment modalities.


Assuntos
Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/metabolismo , Desoxicitidina/análogos & derivados , Fator de Crescimento de Hepatócito/antagonistas & inibidores , Neovascularização Patológica/metabolismo , Neoplasias Pancreáticas/metabolismo , Células Estreladas do Pâncreas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-met/metabolismo , Animais , Anticorpos Monoclonais Humanizados , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Camundongos Nus , Transplante de Neoplasias , Células Estreladas do Pâncreas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
13.
Cancer Lett ; 381(1): 194-200, 2016 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-26571462

RESUMO

Pancreatic stellate cells (PSCs) are responsible for producing the collagenous stroma in pancreatic cancer. Findings from the majority of in vitro and in vivo studies to date indicate that PSCs interact with cancer cells as well as with other cellular elements in the stroma including immune cells, endothelial cells and neuronal cells to set up a growth permissive microenvironment for pancreatic tumours. However, two recent studies reporting a protective effect of myofibroblasts in pancreatic cancer have served to remind researchers of the possibility that the role of PSCs in this disease may be context and time-dependent, such that any possible early protective role of PSCs is subverted in later stages by the ability of cancer cells to turn PSCs into cancer-promoting aides. This concept is supported by the development in recent years of several novel therapeutic approaches targeting the stroma that have been successfully applied in pre-clinical settings to inhibit disease progression. A multi-pronged approach aimed at tumour cells as well as stromal elements may be the key to achieving better clinical outcomes in patients with pancreatic cancer.


Assuntos
Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/patologia , Células Estromais/patologia , Microambiente Tumoral , Animais , Antineoplásicos/uso terapêutico , Comunicação Celular , Humanos , Terapia de Alvo Molecular , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Células Estreladas do Pâncreas/efeitos dos fármacos , Células Estreladas do Pâncreas/metabolismo , Transdução de Sinais , Células Estromais/efeitos dos fármacos , Células Estromais/metabolismo
14.
Alcohol Clin Exp Res ; 39(11): 2123-33, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26463405

RESUMO

BACKGROUND: Chronic pancreatitis, a known complication of alcohol abuse, is characterized histopathologically by prominent fibrosis. Pancreatic stellate cells (PSCs) are responsible for producing this fibrous tissue in chronic pancreatitis and are activated by alcohol. Progression of alcoholic chronic pancreatitis (as assessed by calcification and fibrosis) is thought to be facilitated by concurrent smoking, but the mechanisms are unknown. This study aimed to (a) determine whether human PSCs (hPSCs) and rat PSCs express nicotinic acetylcholine receptors (nAChRs), which are known to bind 2 important components of cigarette smoke, namely nicotine and nicotine-derived nitrosamine ketone (NNK), and (b) examine the effects of cigarette smoke components in the presence and absence of alcohol on PSC activation in vitro. METHODS: Western blotting was used to detect the presence of nAChRs in primary cultures of PSCs. Clinically relevant concentrations of cigarette smoke components (either cigarette smoke extract [CSE], NNK, or nicotine) ± ethanol (EtOH) were used to treat primary cultures of PSCs, and stellate cell activation was assessed by cell migration, proliferation, collagen production, and apoptosis. RESULTS: We demonstrate, for the first time, that PSCs express nAChRs (isoforms α3, α7, ß, ε) and that the expression of the α7 isoform in hPSCs is induced by CSE + EtOH. We also provide novel findings that PSCs are activated by CSE and NNK (both alone and in combination with EtOH) as evidenced by an increase in cell migration and/or proliferation. Further, we demonstrate that activation of PSCs by CSE + EtOH and NNK + EtOH may be mediated via nAChRs on the cells. CONCLUSIONS: PSCs are activated by clinically relevant concentrations of cigarette smoke components (CSE and NNK), alone and in combination with EtOH. Thus, in alcoholics who smoke, progression of pancreatic fibrosis may be facilitated by the combined effects of alcohol and cigarette smoke components on hPSC behavior.


Assuntos
Etanol/toxicidade , Nicotiana/toxicidade , Células Estreladas do Pâncreas/efeitos dos fármacos , Células Estreladas do Pâncreas/patologia , Pancreatite Alcoólica/patologia , Fumaça/efeitos adversos , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Células Cultivadas , Progressão da Doença , Relação Dose-Resposta a Droga , Humanos , Pancreatite Alcoólica/induzido quimicamente , Fumar/efeitos adversos , Fumar/patologia
15.
Curr Opin Gastroenterol ; 31(5): 416-23, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26125317

RESUMO

PURPOSE OF REVIEW: Ever since the first descriptions of methods to isolate pancreatic stellate cells (PSCs) from rodent and human pancreas 17 years ago, rapid advances have been made in our understanding of the biology of these cells and their functions in health and disease. This review updates recent literature in the field, which indicates an increasingly complex role for the cells in normal pancreas, pancreatitis and pancreatic cancer. RECENT FINDINGS: Work reported over the past 12 months includes improved methods of PSC immortalization, a role for PSCs in islet fibrosis, novel factors causing PSC activation as well as those inducing quiescence, and translational research aimed at inhibiting the facilitatory effects of PSCs on disease progression in chronic pancreatitis as well as pancreatic cancer. SUMMARY: Improved understanding of the role of PSCs in pancreatic pathophysiology has prompted a focus on translational studies aimed at developing novel approaches to modulate PSC function in a bid to improve clinical outcomes of two major fibrotic diseases of the pancreas: chronic pancreatitis and pancreatic cancer.


Assuntos
Fibrose/fisiopatologia , Pâncreas/patologia , Neoplasias Pancreáticas/fisiopatologia , Células Estreladas do Pâncreas/fisiologia , Pancreatite Crônica/fisiopatologia , Actinas/biossíntese , Comunicação Celular , Progressão da Doença , Regulação da Expressão Gênica/fisiologia , Humanos , Pâncreas/citologia , Transdução de Sinais
16.
Carcinogenesis ; 35(8): 1891-900, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24876152

RESUMO

Activated cancer-associated human pancreatic stellate cells (CAhPSCs, which produce the collagenous stroma of pancreatic cancer [PC]) are known to play a major role in PC progression. Apart from inducing cancer cell proliferation and migration, CAhPSCs have also been implicated in neoangiogenesis in PC. However, the mechanisms mediating the observed angiogenic effects of CAhPSCs are unknown. A candidate pathway that may be involved in this process is the hepatocyte growth factor (HGF)/c-MET pathway and its helper molecule, urokinase-type plasminogen activator (uPA). This study investigated the effects of CAhPSC secretions on endothelial cell function in the presence and absence of HGF, c-MET and uPA inhibitors. HGF levels in CAhPSC secretions were quantified using ELISA. CAhPSC secretions were then incubated with human microvascular endothelial cells (HMEC-1) and angiogenesis assessed by quantifying HMEC-1 tube formation and proliferation. CAhPSC-secreted HGF significantly increased HMEC-1 tube formation and proliferation; notably, these effects were downregulated by inhibition of HGF, its receptor c-MET and uPA. Phosphorylation of p38 mitogen-activated protein kinase was downregulated during inhibition of the HGF/c-MET pathway, whereas phosphatidylinositol-3 kinase and ERK1/2 remained unaffected. Our studies have shown for the first time that CAhPSCs induce proliferation and tube formation of HMEC-1 and that the HGF/c-MET pathway plays a major role in this induction. Given that standard antiangiogenic treatment targeting vascular endothelial growth factor has had limited success in the clinical setting, the findings of the current study provide strong support for a novel, alternative antiangiogenic approach targeting the HGF/c-MET and uPA pathways in PC.


Assuntos
Carcinoma Ductal Pancreático/patologia , Comunicação Celular/fisiologia , Endotélio Vascular/patologia , Fator de Crescimento de Hepatócito/metabolismo , Neoplasias Pancreáticas/patologia , Células Estreladas do Pâncreas/patologia , Proteínas Proto-Oncogênicas c-met/metabolismo , Inibidores da Angiogênese/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Carcinoma Ductal Pancreático/metabolismo , Comunicação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Endotélio Vascular/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , Neoplasias Pancreáticas/metabolismo , Células Estreladas do Pâncreas/metabolismo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
Front Physiol ; 5: 52, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24592240

RESUMO

Pancreatic cancer is a devastating disease with an unacceptably high mortality to incidence ratio. Traditional therapeutic approaches such as surgery in combination with chemo- or radiotherapy have had limited efficacy in improving the outcome of this disease. Up until just under a decade ago, the prominent desmoplastic reaction which is a characteristic of the majority of pancreatic ductal adenocarcinomas (PDAC) had been largely ignored. However, since the identification of the pancreatic stellate cell (PSC) as the key cell responsible for the production of the collagenous stroma in PDAC, increasing attention has been paid to the role of the stromal reaction in pancreatic cancer pathobiology. There is now compelling evidence that PSCs interact not only with cancer cells themselves, but with several other cell types in the stroma (endothelial cells, immune cells, and possibly neuronal cells) to promote cancer progression. This review summarizes current knowledge in the field about the influence of PSCs and the stromal microenvironment on cancer behavior and discusses novel therapeutic approaches which reflect an increasing awareness amongst clinicians and researchers that targeting cancer cells alone is no longer sufficient to improve patient outcome and that combinatorial treatments targeting the stroma as well as the cancer cells will be required to change the clinical course of this disease.

18.
Expert Rev Mol Diagn ; 14(2): 199-215, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24512138

RESUMO

The diagnostic options for chronic pancreatitis have evolved over recent years. The previous gold standard references for structural imaging and exocrine pancreatic function testing have both been supplanted and redesigned. Endoscopic retrograde pancreatography has now been overtaken by endoscopic ultrasound and magnetic resonance cholangiopancreatography, whilst the old technique for Dreiling tube pancreatic function testing has now been replaced by the endoscopic pancreatic function test. New advances in endoscopic ultrasound elastography have also extended the options for evaluating pancreatic masses to differentiate mass-forming chronic pancreatitis from malignancy. Genetic contribution to chronic pancreatitis is also now more widely recognized than ever before.


Assuntos
Pancreatite Crônica/diagnóstico , Colangiopancreatografia por Ressonância Magnética , Técnicas de Imagem por Elasticidade , Endoscopia , Humanos , Pâncreas/diagnóstico por imagem , Pâncreas/patologia , Testes de Função Pancreática , Pancreatite Crônica/complicações , Pancreatite Crônica/genética , Reprodutibilidade dos Testes , Ultrassonografia
19.
Am J Physiol Gastrointest Liver Physiol ; 305(6): G408-17, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23868411

RESUMO

Activated pancreatic stellate cells (PSCs) are responsible for the fibrotic matrix of chronic pancreatitis and pancreatic cancer. In vitro protocols examining PSC biology have usually involved PSCs cultured on plastic, a nonphysiological surface. However, PSCs cultured on physiological matrices, e.g., Matrigel (normal basement membrane) and collagen (fibrotic pancreas), may have distinctly different behaviors compared with cells cultured on plastic. Therefore, we aimed to 1) compare PSC gene expression after culture on plastic, Matrigel, and collagen I; 2) validate the gene array data for transgelin, the most highly dysregulated gene in PSCs grown on activating vs. nonactivating matrices, at mRNA and protein levels; 3) examine the role of transgelin in PSC function; and 4) assess transgelin expression in human chronic pancreatitis sections. Culture of PSCs on different matrices significantly affected their gene expression pattern. 146, 619, and 432 genes, respectively, were differentially expressed (P < 0.001) in PSCs cultured on collagen I vs. Matrigel, Matrigel vs. plastic, and collagen I vs. plastic. The highest fold change (12.5-fold upregulation) in gene expression in cells on collagen I vs. Matrigel was observed for transgelin (an actin stress fiber-associated protein). Transgelin was significantly increased in activated PSCs vs. quiescent PSCs. Silencing transgelin expression decreased PSC proliferation and also reduced platelet-derived growth factor-induced PSC migration. Notably, transgelin was highly expressed in chronic pancreatitis in stromal areas and periacinar spaces but was absent in acinar cells. These findings suggest that transgelin is a potentially useful target protein to modulate PSC function so as to ameliorate pancreatic fibrosis.


Assuntos
Matriz Extracelular/química , Proteínas dos Microfilamentos/metabolismo , Proteínas Musculares/metabolismo , Células Estreladas do Pâncreas/metabolismo , Transcrição Gênica , Animais , Proliferação de Células , Células Cultivadas , Colágeno/farmacologia , Combinação de Medicamentos , Matriz Extracelular/metabolismo , Humanos , Laminina/farmacologia , Masculino , Proteínas dos Microfilamentos/genética , Proteínas Musculares/genética , Células Estreladas do Pâncreas/efeitos dos fármacos , Células Estreladas do Pâncreas/fisiologia , Plásticos/farmacologia , Proteoglicanas/farmacologia , Ratos , Ratos Sprague-Dawley
20.
Front Physiol ; 3: 344, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22973234

RESUMO

While the morphology and function of cells of the exocrine and endocrine pancreas have been studied over several centuries, one important cell type in the gland, the pancreatic stellate cell (PSC), had remained undiscovered until as recently as 20 years ago. Even after its first description in 1982, it was to be another 16 years before its biology could begin to be studied, because it was only in 1998 that methods were developed to isolate and culture PSCs from rodent and human pancreas. PSCs are now known to play a critical role in pancreatic fibrosis, a consistent histological feature of two major diseases of the pancreas-chronic pancreatitis and pancreatic cancer. In health, PSCs maintain normal tissue architecture via regulation of the synthesis and degradation of extracellular matrix (ECM) proteins. Recent studies have also implied other functions for PSCs as progenitor cells, immune cells or intermediaries in exocrine pancreatic secretion in humans. During pancreatic injury, PSCs transform from their quiescent phase into an activated, myofibroblast-like phenotype that secretes excessive amounts of ECM proteins leading to the fibrosis of chronic pancreatitis and pancreatic cancer. An ever increasing number of factors that stimulate and/or inhibit PSC activation via paracrine and autocrine pathways are being identified and characterized. It is also now established that PSCs interact closely with pancreatic cancer cells to facilitate cancer progression. Based on these findings, several therapeutic strategies have been examined in experimental models of chronic pancreatitis as well as pancreatic cancer, in a bid to inhibit/retard PSC activation and thereby alleviate chronic pancreatitis or reduce tumor growth in pancreatic cancer. The challenge that remains is to translate these pre-clinical developments into clinically applicable treatments for patients with chronic pancreatitis and pancreatic cancer.

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