The primary aim of this study was to evaluate the antitumor efficacy of the bromodomain inhibitor JQ1 in pancreatic ductal adenocarcinoma (PDAC) patient-derived xenograft (tumorgraft) models. A ...secondary aim of the study was to evaluate whether JQ1 decreases expression of the oncogene c-Myc in PDAC tumors, as has been reported for other tumor types. We used five PDAC tumorgraft models that retain specific characteristics of tumors of origin to evaluate the antitumor efficacy of JQ1. Tumor-bearing mice were treated with JQ1 (50 mg/kg daily for 21 or 28 days). Expression analyses were performed with tumors harvested from host mice after treatment with JQ1 or vehicle control. An nCounter PanCancer Pathways Panel (NanoString Technologies) of 230 cancer-related genes was used to identify gene products affected by JQ1. Quantitative RT-PCR, immunohistochemistry and immunoblots were carried out to confirm that changes in RNA expression reflected changes in protein expression. JQ1 inhibited the growth of all five tumorgraft models (P<0.05), each of which harbors a KRAS mutation; but induced no consistent change in expression of c-Myc protein. Expression profiling identified CDC25B, a regulator of cell cycle progression, as one of the three RNA species (TIMP3, LMO2 and CDC25B) downregulated by JQ1 (P<0.05). Inhibition of tumor progression was more closely related to decreased expression of nuclear CDC25B than to changes in c-Myc expression. JQ1 and other agents that inhibit the function of proteins with bromodomains merit further investigation for treating PDAC tumors. Work is ongoing in our laboratory to identify effective drug combinations that include JQ1.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Background
The aim of the study was to compare the outcomes of patients with pancreatic or peripancreatic walled‐off necrosis by endoscopy using the conventional approach versus an algorithmic ...approach based on the collection size, location and stepwise response to intervention.
Methods
This was an observational before–after study of consecutive patients managed over two time intervals. In the initial period (2004–2009) symptomatic patients with walled‐off necrosis underwent conventional single transmural drainage with placement of two stents and a nasocystic catheter, followed by direct endoscopic necrosectomy, if required. In the later period (2010–2013) an algorithmic approach was adopted based on size and extent of the walled‐off necrosis and stepwise response to intervention. The main outcome was treatment success, defined as a reduction in walled‐off necrosis size to 2 cm or less on CT after 8 weeks.
Results
Forty‐seven patients were treated in the first interval and 53 in the second. There was no difference in patient demographics, clinical or walled‐off necrosis characteristics and laboratory parameters between the groups, apart from a higher proportion of women and Caucasians in the later period. The treatment success rate was higher for the algorithmic approach compared with conventional treatment (91 versus 60 per cent respectively; P < 0·001). On multivariable logistic regression, management based on the algorithm was the only predictor of treatment success (odds ratio 6·51, 95 per cent c.i. 2·19 to 19·37; P = 0·001).
Conclusion
An algorithmic approach to pancreatic and peripancreatic walled‐off necrosis, based on the collection size, location and stepwise response to intervention, resulted in an improved rate of treatment success compared with conventional endoscopic management.
Tailored approach improves outcomes
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We sought to investigate the role of ErbB3-mediated signalling on the interaction between pancreatic cancer-associated fibroblasts (CAF) and carcinoma cells in an effort to disrupt tumourigenic ...pancreatic ductal adenocarcinoma (PDAC) stromal-epithelial cross-communication.
Primary CAF cultures were established from human PDAC surgical specimens. AsPC-1 pancreatic cancer cell murine subcutaneous xenografts were developed in the presence and absence of CAF and were subsequently treated with epidermal growth factor receptor (EGFR) inhibitors (erlotinib) and ErbB3 inhibitors (MM-121, monoclonal ErbB3 antibody).
Cancer-associated fibroblasts were found to secrete neuregulin-1 (NRG-1), which promoted proliferation via phosphorylation of ErbB3 and AKT in AsPC-1 PDAC cells. This signalling cascade was effectively inhibited both in vitro and in vivo by specific ErbB3 blockade with MM-121, with greater degree of tumourigenesis inhibition when combined with erlotinib. The CAF-AsPC-1 pancreatic cancer xenografts reached significantly greater tumour volume than those xenografts lacking CAF and were resistant to the anti-tumour effects of EGFR inhibition with erlotinib.
Cancer-associated fibroblasts-derived NRG-1 promote PDAC tumourigenesis via ErbB3-AKT signalling and overcomes single-agent EGFR inhibition. Disruption of this stromally mediated tumourigenic mechanism is best obtained through combined EGFR-ErbB3 inhibition with both erlotinib and MM-121. We have identified the NRG-1/ErbB3 axis as an attractive molecular target for the interruption of tumourigenic stromal-epithelial interactions within the PDAC microenvironment.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Purpose
(1) To determine the safety of the epidermal growth factor receptor (EGFR) antibody cetuximab with concurrent gemcitabine and abdominal radiation in the treatment of patients with locally ...advanced adenocarcinoma of the pancreas. (2) To evaluate the feasibility of pancreatic cancer cell epithelial–mesenchymal transition (EMT) molecular profiling as a potential predictor of response to anti-EGFR treatment.
Methods
Patients with non-metastatic, locally advanced pancreatic cancer were treated in this dose escalation study with gemcitabine (0–300 mg/m
2
/week) given concurrently with cetuximab (400 mg/m
2
loading dose, 250 mg/m
2
weekly maintenance dose) and abdominal irradiation (50.4 Gy). Expression of E-cadherin and vimentin was assessed by immunohistochemistry in diagnostic endoscopic ultrasound fine-needle aspiration (EUS-FNA) specimens.
Results
Sixteen patients were enrolled in 4 treatment cohorts with escalating doses of gemcitabine. Incidence of grade 1–2 adverse events was 96%, and incidence of 3–4 adverse events was 9%. There were no treatment-related mortalities. Two patients who exhibited favorable treatment response underwent surgical exploration and were intraoperatively confirmed to have unresectable tumors. Median overall survival was 10.5 months. Pancreatic cancer cell expression of E-cadherin and vimentin was successfully determined in EUS-FNA specimens from 4 patients.
Conclusions
Cetuximab can be safely administered with abdominal radiation and concurrent gemcitabine (up to 300 mg/m
2
/week) in patients with locally advanced adenocarcinoma of the pancreas. This combined therapy modality exhibited limited activity. Diagnostic EUS-FNA specimens could be analyzed for molecular markers of EMT in a minority of patients with pancreatic cancer.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Purpose: Gastrointestinal stromal tumors (GIST) are characterized by expressing a gain-of-function mutation in KIT , and to a lesser extent, PDGFR . Imatinib mesylate, a tyrosine kinase inhibitor, ...has activity against GISTs that contain oncogenic mutations of KIT. In this
study, KIT and PDGFRα mutation status was analyzed and protein modeling approaches were used to assess the potential effect of KIT mutations in response to imatinib therapy.
Experimental Design: Genomic DNA was isolated from GIST tumors. Exons 9, 11, 13, and 17 of c- KIT and exons 12, 14, and 18 of PDGFRα were evaluated for oncogenic mutations. Protein modeling was used to assess mutations within the juxtamembrane region and
the kinase domain of KIT.
Results: Mutations in KIT exons 9, 11, and 13 were identified in GISTs with the majority of changes involving the juxtamembrane region of KIT. Molecular
modeling indicates that mutations in this region result in disruption of the KIT autoinhibited conformation, and lead to gain-of-function
activation of the kinase. Furthermore, a novel germ-line mutation in KIT was identified that is associated with an autosomal dominant predisposition to the development of GIST.
Conclusions: We have used protein modeling and structural analyses to elucidate why patients with GIST tumors containing exon 11 mutations
are the most responsive to imatinib mesylate treatment. Importantly, mutations detected in this exon and others displayed
constitutive activation of KIT. Furthermore, we have found tumors that are both KIT and PDGFRα mutation negative, suggesting that additional, yet unidentified, abnormalities may contribute to GIST tumorigenesis.
Serum-biomarker based screening for pancreatic cancer could greatly improve survival in appropriately targeted high-risk populations.
Eighty-three circulating proteins were analyzed in sera of ...patients diagnosed with pancreatic ductal adenocarcinoma (PDAC, n = 333), benign pancreatic conditions (n = 144), and healthy control individuals (n = 227). Samples from each group were split randomly into training and blinded validation sets prior to analysis. A Metropolis algorithm with Monte Carlo simulation (MMC) was used to identify discriminatory biomarker panels in the training set. Identified panels were evaluated in the validation set and in patients diagnosed with colon (n = 33), lung (n = 62), and breast (n = 108) cancers.
Several robust profiles of protein alterations were present in sera of PDAC patients compared to the Healthy and Benign groups. In the training set (n = 160 PDAC, 74 Benign, 107 Healthy), the panel of CA 19-9, ICAM-1, and OPG discriminated PDAC patients from Healthy controls with a sensitivity/specificity (SN/SP) of 88/90%, while the panel of CA 19-9, CEA, and TIMP-1 discriminated PDAC patients from Benign subjects with an SN/SP of 76/90%. In an independent validation set (n = 173 PDAC, 70 Benign, 120 Healthy), the panel of CA 19-9, ICAM-1 and OPG demonstrated an SN/SP of 78/94% while the panel of CA19-9, CEA, and TIMP-1 demonstrated an SN/SP of 71/89%. The CA19-9, ICAM-1, OPG panel is selective for PDAC and does not recognize breast (SP = 100%), lung (SP = 97%), or colon (SP = 97%) cancer.
The PDAC-specific biomarker panels identified in this investigation warrant additional clinical validation to determine their role in screening targeted high-risk populations.
We previously demonstrated that pancreatic adenocarcinoma BxPC-3 xenografts display resistance to treatment with Erbitux, gemcitabine, and radiation, whereas MIA PaCa-2 xenografts are highly ...sensitive to the same therapy. Here, we elucidate in vitro mechanisms that may explain the observed differential response of epidermal growth factor receptor (EGFR) expressing pancreatic adenocarcinoma xenografts to Erbitux-based combination therapy in vivo. MIA PaCa-2 and BxPC-3 protein lysates were probed with antibodies to EGFR, ErbB2, ErbB3, and ErbB4. Constitutive ErbB3 activity was visualized by immunoblot analysis using anti-phosphotyrosine antibodies and receptor-specific immunoprecipitates.
erbB2 and
erbB3 gene expression in both cell lines was quantified with real-time polymerase chain reaction. Erbitux-induced internalization of EGFR was determined by flow cytometry following Erbitux treatment for different incubation times at 0°C and 37°C. MIA PaCa-2 and BxPC-3 protein extracts were also probed with anti–phospho–mitogen-activated protein kinase antibody after stimulation with EGF and in the presence of Erbitux. Although both cell lines expressed EGFR and ErbB2 protein, ErbB3 protein was selectively expressed by BxPC-3 cells, where it also showed evidence of constitutive phosphorylation. There was a 10-fold increase of
erbB3 transcript levels in BxPC-3 cells compared with MIA PaCa-2. ErbB4 protein was not detectable in either cell line. Erbitux mediated EGFR internalization in MIA PaCa-2 cells after 2 hours of incubation, whereas it did not promote EGFR internalization in BxPC-3 cells. Likewise, EGF-dependent phosphorylation of MAPK p44/42 was blocked by Erbitux treatment in MIA PaCa-2 but not BxPC-3 cells. Erbitux selectively interfered with EGF-induced MAPK activation in MIA PaCa-2 but not BxPC-3 cells. Persistent MAPK activation and impaired in vitro internalization of EGFR by BxPC-3 pancreatic cancer cells may be due to constitutive ErbB3 signaling, facilitated by heterodimerization with EGFR, which may explain resistance to Erbitux-based combination therapy in vivo.
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UL, UM, UPUK, VKSCE, ZAGLJ
The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Pancreatic Adenocarcinoma discuss the workup and management of tumors of the exocrine pancreas. These NCCN Guidelines Insights ...provide a summary and explanation of major changes to the 2012 NCCN Guidelines for Pancreatic Adenocarcinoma. The panel made 3 significant updates to the guidelines: 1) more detail was added regarding multiphase CT techniques for diagnosis and staging of pancreatic cancer, and pancreas protocol MRI was added as an emerging alternative to CT; 2) the use of a fluoropyrimidine plus oxaliplatin (e.g., 5-FU/leucovorin/oxaliplatin or capecitabine/oxaliplatin) was added as an acceptable chemotherapy combination for patients with advanced or metastatic disease and good performance status as a category 2B recommendation; and 3) the panel developed new recommendations concerning surgical technique and pathologic analysis and reporting.
Background: Our purpose was to determine whether the combination of total liver vascular inflow occlusion (Pringle maneuver) and rapid hepatic transection with a clamp-crush technique results in ...significant reduction of blood loss and transfusion requirements during major hepatic resections.
Methods: A series of 49 adult patients underwent major hepatic resections for metastatic disease between April 1, 1992, and March 31, 1998. Group 1 patients (n = 15) had standard hilar dissection and finger-fracture hepatic transection without total liver inflow occlusion. Group 2 patients (n = 34) had total liver inflow occlusion and clamp-crush parenchymal transection.
Results: Median blood loss was 1600 mL for group 1 and 500 mL for group 2 (
P = .001). Eleven (73%) patients in group 1 required intraoperative blood transfusion (median 2 units) compared with 7 (21%) in group 2 with a median of 0 units (
P = .001 and
P < .001, respectively). Of the 7 patients in group 2 who required transfusion, 3 had a preoperative hemoglobin below 10 g/dL, 1 required splenectomy for operative injury, and 1 underwent a concomitant complicated small bowel resection.
Conclusions: Major hepatic resections can be performed without transfusion of blood products when preoperative hemoglobin is above 10 g/dL and concomitant major surgical procedures are not required. (Surgery 1999;125:166-71.)
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IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We report on a 51-year-old man with severe two-vessel coronary disease and an ejection fraction of 15% who presented with myocardial ischemia and heparin-induced thrombocytopenia after coronary ...angioplasty. Before coronary bypass surgery, the antithrombin agent argatroban was used for anticoagulation and an intra-aortic balloon pump was inserted. Direct coronary bypass surgery was performed to the left anterior descending artery and to the posterior descending artery using the ‘Octopus’ tissue stabilization device (Manfrotto, Feltre, Italy). The postoperative course was uneventful and associated with normal platelet counts. The patient was discharged on the 6th postoperative day.
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