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112 result(s) for "Kocher, H M"
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Periostin promotes invasiveness and resistance of pancreatic cancer cells to hypoxia-induced cell death: role of the β4 integrin and the PI3k pathway
Pancreatic ductal adenocarcinoma is a devastating disease, characterized by a rapid progression and poor treatment response. Using gene expression profiling of pancreatic cancer tissues, we previously identified periostin as a potential diagnostic and therapeutic target. In this study, we report the overexpression of periostin in a larger set of pancreatic cancer tissues and show that although the periostin transcript is exclusively expressed in tumour cells, the protein product is only detected in the extracellular matrix adjacent to cancer cells. Using an enzyme-linked immunosorbent assay (ELISA) assay, we show significantly increased levels of periostin in the sera of pancreatic cancer patients compared to non-cancer controls. We demonstrate that periostin promotes the invasiveness of tumour cells by increasing the motility of cells without inducing expression of proteases, and enhances the survival of tumour cells exposed to hypoxic conditions. At the molecular level, we provide evidence that the α 6 β 4 integrin complex acts as the cell receptor of periostin in pancreatic cancer cells and that interaction promotes phosphorylation of focal adhesion kinase (FAK) and protein kinase B (AKT) though activation of the PI3 kinase pathway, but not the RAS/MEK/ERK pathway. These findings suggest an important role of periostin in pancreatic cancer and provide a rationale to study periostin for diagnostic and therapeutic applications.
Complications of biliary-enteric anastomoses
INTRODUCTION Biliary-enteric anastomoses are performed for a range of indications and may result in early and late complications. The aim of this study was to assess the risk factors and management of anastomotic leak and stricture following biliary-enteric anastomosis. METHODS A retrospective analysis of the medical records of patients who underwent biliary-enteric anastomoses in a tertiary referral centre between 2000 and 2010 was performed. RESULTS Four hundred and sixty-two biliary-enteric anastomoses were performed. Of these, 347 (75%) were performed for malignant disease. Roux-en-Y hepaticojejunostomy or choledocho-jejunostomy were performed in 440 (95%) patients. Perioperative 30-day mortality was 6.5% (n=30). Seventeen patients had early bile leaks (3.7%) and 17 had late strictures (3.7%) at a median of 12 months. On univariable logistic regression analysis, younger age was a significant risk factor for biliary anastomotic leak. However, on multivariable analysis only biliary reconstruction following biliary injury (odds ratio [OR]=6.84; p=0.002) and anastomosis above the biliary confluence (OR=4.62; p=0.03) were significant. Younger age and biliary reconstruction following injury appeared to be significant risk factors for biliary strictures but multivariable analysis showed that only younger age was significant. CONCLUSIONS Biliary-enteric anastomoses have a low incidence of early and late complications. Biliary reconstruction following injury and a high anastomosis (above the confluence) are significant risk factors for anastomotic leak. Younger patients are significantly more likely to develop an anastomotic stricture over the longer term.
Systematic review of the incidence, presentation and management of gastroduodenal artery pseudoaneurysm after pancreatic resection
Background Gastroduodenal artery (GDA) pseudoaneurysm is a serious complication following pancreatic resection, associated with high morbidity and mortality rates. This review aimed to report the incidence of GDA pseudoaneurysm after pancreatic surgery, and describe clinical presentation and management. Methods MEDLINE and Embase were searched systematically for clinical studies evaluating postoperative GDA pseudoaneurysm. Incidence was calculated by dividing total number of GDA pseudoaneurysms by the total number of pancreatic operations. Additional qualitative data related to GDA pseudoaneurysm presentation and management following pancreatic resection were extracted and reviewed from individual reports. Results Nine studies were selected for systematic review involving 4227 pancreatic operations with 55 GDA pseudoaneurysms, with a reported incidence of 1·3 (range 0·2–8·3) per cent. Additional data were extracted from 39 individual examples of GDA pseudoaneurysm from 14 studies. The median time for haemorrhage after surgery was at 15 (range 4–210) days. A preceding complication in the postoperative period was documented in four of 21 patients (67 per cent), and sentinel bleeding was observed in 14 of 20 patients (70 per cent). Postoperative complications after pseudoaneurysm management occurred in two‐thirds of the patients (14 of 21). The overall survival rate was 85 per cent (33 of 39). Conclusion GDA pseudoaneurysm is a rare yet serious cause of haemorrhage after pancreatic surgery, with high mortality. The majority of the patients had a preceding complication. Sentinel bleeding was an important clinical indicator. Antecedentes El pseudoaneurisma (PA) de la arteria gastroduodenal (gastroduodenal artery, GDA) es una complicación grave después de la resección pancreática que conlleva elevadas tasas altas de morbilidad y mortalidad. Esta revisión tiene como objetivo estudiar la incidencia de PA de la GDA tras cirugía pancreática y describir la forma de presentación clínica y el tratamiento. Métodos Se realizó una búsqueda sistemática en MEDLINE y EMBASE de los estudios clínicos que analizasen el PA postoperatorio de la GDA. Se calculó la incidencia dividiendo el número total de PA de GDA por el número total de intervenciones pancreáticas. De los informes de cada caso, se extrajeron los datos cualitativos relacionados con la forma de presentación y el tratamiento del PA de la GDA tras la resección pancreática. Resultados Para la revisión sistemática se seleccionaron nueve estudios con 4.227 intervenciones sobre el páncreas y 55 PA de la GDA (incidencia 1,30% (rango 0,22‐8,33%). Se obtuvieron, además, datos individuales de 39 casos de PA de la GDA en 14 estudios. La hemorragia se presentó, como mediana, el día 15 (rango: 4‐210) del postoperatorio. Fue precedida de una complicación postoperatoria en el 66,7% de los casos y se observó una hemorragia centinela en el 70,0% de los pacientes. En dos tercios de los pacientes hubo complicaciones postoperatorias después del tratamiento del PA y la supervivencia global fue del 84,6%. Conclusión Los PA de la GDA son una causa poco frecuente, pero grave, de hemorragia después de la cirugía pancreática, con una elevada mortalidad. La mayoría de los pacientes presentaron alguna complicación previa. La hemorragia centinela fue un indicador clínico de importancia. The management of gastroduodenal artery (GDA) pseudoaneurysm is primarily endovascular, with the exact method dependent on vessel anatomy, clinical state of the patient, collateral hepatic blood flow and interval from index surgery. Remains an unusual but important complication
ADAM12 is a circulating marker for stromal activation in pancreatic cancer and predicts response to chemotherapy
Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant stroma that harbors tumor-promoting properties. No good biomarkers exist to monitor the effect of stromal targeting therapies or to predict response. We set out to identify such non-invasive markers for PDAC stroma and predict response to therapy. Gene expression datasets, co-culture experiments, xenografts, and patient samples were analyzed. Serum samples were measured from a cohort of 58 resected patients, and 87 metastatic or locally advanced PDAC patients. Baseline and follow-up levels were assessed in 372 additional metastatic PDAC patients who received nab-paclitaxel with gemcitabine (n = 184) or gemcitabine monotherapy (n = 188) in the phase III MPACT trial. Increased levels of ADAM12 were found in PDAC patients compared to healthy controls (p < 0.0001, n = 157 and n = 38). High levels of ADAM12 significantly associated with poor outcome in resected PDAC (HR 2.07, p = 0.04). In the MPACT trial survival was significantly longer for patients who received nab-paclitaxel and had undetectable ADAM12 levels before treatment (OS 12.3 m vs 7.9 m p = 0.0046). Consistently undetectable or decreased ADAM12 levels during treatment significantly associated with longer survival as well (OS 14.4 m and 11.2 m, respectively vs 8.3, p = 0.0054). We conclude that ADAM12 is a blood-borne proxy for stromal activation, the levels of which have prognostic significance and correlate with treatment benefit.
Switchable CAR-T cells mediate remission in metastatic pancreatic ductal adenocarcinoma
ObjectivePancreatic ductal adenocarcinoma (PDAC) is a disease of unmet medical need. While immunotherapy with chimeric antigen receptor T (CAR-T) cells has shown much promise in haematological malignancies, their efficacy for solid tumours is challenged by the lack of tumour-specific antigens required to avoid on-target, off-tumour effects. Switchable CAR-T cells whereby activity of the CAR-T cell is controlled by dosage of a tumour antigen-specific recombinant Fab-based ‘switch’ to afford a fully tunable response may overcome this translational barrier.DesignIn this present study, we have used conventional and switchable CAR-T cells to target the antigen HER2, which is upregulated on tumour cells, but also present at low levels on normal human tissue. We used patient-derived xenograft models derived from patients with stage IV PDAC that mimic the most aggressive features of PDAC, including severe liver and lung metastases.ResultsSwitchable CAR-T cells followed by administration of the switch directed against human epidermal growth factor receptor 2 (HER2)-induced complete remission in difficult-to-treat, patient-derived advanced pancreatic tumour models. Switchable HER2 CAR-T cells were as effective as conventional HER2 CAR-T cells in vivo testing a range of different CAR-T cell doses.ConclusionThese results suggest that a switchable CAR-T system is efficacious against aggressive and disseminated tumours derived from patients with advanced PDAC while affording the potential safety of a control switch.
A novel function of colony-stimulating factor 1 receptor in hTERT immortalization of human epithelial cells
The receptor for macrophage colony-stimulating factor 1 receptor (CSF1R) is a product of the proto-oncogene c-fms and a member of the class III transmembrane tyrosine kinase receptor family. Earlier, we described increased mRNA expression of CSF1R in human telomerase reverse transcriptase (hTERT) immortalized human ovarian surface epithelial (IOSE) cell lines derived from a single donor. Here, we further describe that CSF1R is upregulated at both the mRNA and protein level in hTERT immortalized human normal OSE cells from two different donors and in hTERT immortalized human pancreatic ductal epithelial cells. CSF1R was not upregulated in hTERT immortalized epithelial clones that subsequently underwent senescence or in immortalized fibroblasts. Upon stimulation by the CSF1R ligand CSF1, the immortalized epithelial cell lines showed rapid internalization of CSF1R with concomitant down-modulation and colocalization of phosphorylated NFκBp65 with hTERT protein, hTERT translocation into the nucleus and the binding of c-Myc to the hTERT promoter region. Reducing the expression of CSF1R using short hairpin interfering RNA abolished these effects and also decreased cell survival and the number of population doublings under suboptimal culture conditions. The telomerase inhibitor GRN163L confirmed a role for telomerase in the cleavage of the intracellular domain of CSF1R. On the basis of these findings, we suggest that CSF1R may be a critical factor facilitating hTERT immortalization of epithelial cells.
Ezrin interacts with cortactin to form podosomal rosettes in pancreatic cancer cells
Background and aims:Pancreatic cancer is a highly invasive malignancy. Ezrin, a plasma membrane–cytoskeletal linker protein, is associated with the invasive behaviour of cancers. The purpose of this study was to elucidate a possible molecular mechanism for the invasive phenotype.Methods:Using a combination of techniques, such as western blotting, co-immunoprecipitation, confocal and light microscopy, invasion and adhesion assays, organotypic cultures and human samples as well as RNA interference (RNAi) and expression of various mutant ezrin constructs, the dynamic molecular nature of podosomes in pancreatic cancer was dissected out.Results:Podosome and podosomal rosette formation in pancreatic carcinoma (PaCa3) cells is ezrin dependent and associated with adhesion to fibronectin with subsequent digestion of this substrate. Ezrin binds to increasing amounts of cortactin during formation of the podosomal rosette, with the C-terminal region, specifically the actin-binding domain, mediating this molecular linkage. Further, it is shown that phosphorylation of Tyr353 and Thr567 sites on ezrin (conventionally shown to translocate ezrin to the plasma membrane) is not required for podosome formation. The podosomal rosette is revealed to be a highly dynamic and transient structure, which can metamorphose into other cellular processes, such as filopodia or lamellipodia, and thereby enable epithelial cancer cells to “palpate” the underlying substrate and modify their cytoskeletal behaviour accordingly. In human tumour tissues and organotypic cultures, specific subcellular expression of ezrin (basal membranous; cellular processes invading stroma) in pancreatic cancer cells can be correlated with tumour progression and disease-free survival (log-rank test (Mantel–Cox), p = 0.019).Conclusion:Podosomes and their rosettes are driven by ezrin–cortactin interaction and this plays a role in pancreatic cancer invasion.
Phase I clinical trial repurposing all-trans retinoic acid as a stromal targeting agent for pancreatic cancer
Pre-clinical models have shown that targeting pancreatic stellate cells with all-trans-retinoic-acid (ATRA) reprograms pancreatic stroma to suppress pancreatic ductal adenocarcinoma (PDAC) growth. Here, in a phase Ib, dose escalation and expansion, trial for patients with advanced, unresectable PDAC (n = 27), ATRA is re-purposed as a stromal-targeting agent in combination with gemcitabine-nab-paclitaxel chemotherapy using a two-step adaptive continual re-assessment method trial design. The maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D, primary outcome) is the FDA/EMEA approved dose of gemcitabine-nab-paclitaxel along-with ATRA (45 mg/m 2 orally, days 1–15/cycle). Dose limiting toxicity (DLT) is grade 4 thrombocytopenia (n = 2). Secondary outcomes show no detriment to ATRA pharmacokinetics.. Median overall survival for RP2D treated evaluable population, is 11.7 months (95%CI 8.6–15.7 m, n = 15, locally advanced (2) and metastatic (13)). Exploratory pharmacodynamics studies including changes in diffusion-weighted (DW)-MRI measured apparent diffusion coefficient after one cycle, and, modulation of cycle-specific serum pentraxin 3 levels over various cycles indicate stromal modulation. Baseline stromal-specific retinoid transport protein (FABP5, CRABP2) expression may be predicitve of response. Re-purposing ATRA as a stromal-targeting agent with gemcitabine-nab-paclitaxel is safe and tolerable. This combination will be evaluated in a phase II randomized controlled trial for locally advanced PDAC. Clinical trial numbers: EudraCT: 2015-002662-23; NCT03307148. Trial acronym: STARPAC. All-trans retinoic acid - ATRA- is known to remodulate the stroma of pancreatic cancer in mice. Here, the authors carried out a Phase Ib trial in pancreatic patients and show that ATRA in combination with chemotherapy is a safe potential treatment for patients with advanced pancreatic cancer, and demonstrate a stromal modulatory effect.
JAK V617F missense mutation is absent in pancreatic cancer
8 IL-4 interacts with IL-13Rα2 receptor and, although IL-13Rα2 does not bind with STAT3 directly, it blocks STAT6 activation and excludes this downstream event. [...]IL-4 can have an anti-apoptotic effect in glioblastoma cells via STAT3 signalling.
Study protocol: multi-centre, randomised controlled clinical trial exploring stromal targeting in locally advanced pancreatic cancer; STARPAC2
Background Pancreatic cancer (PDAC: pancreatic ductal adenocarcinoma, the commonest form), a lethal disease, is best treated with surgical excision but is feasible in less than a fifth of patients. Around a third of patients presentlocally advanced, inoperable, non-metastatic (laPDAC), whose stadrd of care is palliative chemotherapy; a small minority are down-sized sufficiently to enable surgical excision. We propose a phase II clinical trial to test whether a combination of standard chemotherapy (gemcitabine & nab-Paclitaxel: GEM-NABP) and repurposing All Trans Retinoic Acid (ATRA) to target the stroma may extend progression-free survival and enable successful surgical resection for patients with laPDAC, since data from phase IB clinical trial demonstrate safety of GEM-NABP-ATRA combination to patients with advanced PDAC with potential therapeutic benefit. Methods Patients with laPDAC will receive at least six cycles of GEM-NABP with 1:1 randomisation to receive this with or without ATRA to assess response, until progression or intolerance. Those with stable/responding disease may undergo surgical resection. Primary endpoint is progression free survival (PFS) defined as the time from the date of randomisation to the date of first documented tumour progression (response evaluation criteria in solid tumours [RECIST] v1.1) or death from any cause, whichever occurs first. Secondary endpoints include objective response rate (ORR), overall survival (OS), safety and tolerability, surgical resection rate, R0 surgical resection rate and patient reported outcome measures (PROMS) as measured by questionnaire EQ-5D-5L. Exploratory endpoints include a decrease or increase in CA19-9 and serum Vitamin A over time correlated with ORR, PFS, and OS. Discussion STARPAC2 aims to assess the role of stromal targeting in laPDAC. Trial registration EudraCT: 2019–004231-23; NCT04241276; ISRCTN11503604.