56 research outputs found
The reg4 Gene, Amplified in the Early Stages of Pancreatic Cancer Development, Is a Promising Therapeutic Target
BACKGROUND: The aim of our work was to identify the genes specifically altered in pancreatic adenocarcinoma and especially those that are altered early in cancer development. METHODOLOGY/PRINCIPAL FINDINGS: Gene copy number was systematically assessed with an ultra-high resolution CGH oligonucleotide microarray in DNA from samples of pancreatic cancer. Several new cancer-associated variations were observed. In this work we focused on one of them, involving the reg4 gene. Gene copy number gain of the reg4 gene was confirmed by qPCR in 14 cancer samples. It was also found with increased copy number in most PanIN3 samples. The relationship betweena gain in reg4 gene copy number and cancer development was investigated on the human pancreatic cancer cell line Mia-PaCa2 xenografted under the skin of nude mice. When cells were transfected with a vector allowing reg4 expression, they generated tumors almost twice larger in size. In addition, these tumors were more resistant to gemcitabine treatment than control tumors. Interestingly, weekly intraperitoneal administration of a monoclonal antibody to reg4 halved the size of tumors generated by Mia-PaCa2 cells, suggesting that the antibody interfered with a paracrine/autocrine mechanism involving reg4 and stimulating cancer progression. The addition of gemcitabine resulted in further reduction, tumors becoming 5 times smaller than control. Exposure to reg4 antibody resulted in a significant decrease in intra-tumor levels of pAkt, Bcl-xL, Bcl-2, survivin and cyclin D1. CONCLUSIONS/SIGNIFICANCE: It was concluded that adjuvant therapies targeting reg4 could improve the standard treatment of pancreatic cancer with gemcitabine
Adjuvant gemcitabine versus NEOadjuvant gemcitabine/oxaliplatin plus adjuvant gemcitabine in resectable pancreatic cancer: a randomized multicenter phase III study (NEOPAC study)
<p>Abstract</p> <p>Background</p> <p>Despite major improvements in the perioperative outcome of pancreas surgery, the prognosis of pancreatic cancer after curative resection remains poor. Adjuvant chemotherapy increases disease-free and overall survival, but this treatment cannot be offered to a significant proportion of patients due to the surgical morbidity. In contrast, almost all patients can receive (neo)adjuvant chemotherapy before surgery. This treatment is safe and effective, and has resulted in a median survival of 26.5 months in a recent phase II trial. Moreover, neoadjuvant chemotherapy improves the nutritional status of patients with pancreatic cancer. This multicenter phase III trial (NEOPAC) has been designed to explore the efficacy of neoadjuvant chemotherapy.</p> <p>Methods/Design</p> <p>This is a prospective randomized phase III trial. Patients with resectable cytologically proven adenocarcinoma of the pancreatic head are eligible for this study. All patients must be at least 18 years old and must provide written informed consent. An infiltration of the superior mesenteric vein > 180° or major visceral arteries are considered exclusion criteria. Eligible patients will be randomized to surgery followed by adjuvant gemcitabine (1000 mg/m<sup>2</sup>) for 6 months or neoadjuvant chemotherapy (gemcitabine 1000 mg/m<sup>2</sup>, oxaliplatin 100 mg/m<sup>2</sup>) followed by surgery and the same adjuvant treatment. Neoadjuvant chemotherapy is given four times every two weeks. The staging as well as the restaging protocol after neoadjuvant chemotherapy include computed tomography of chest and abdomen and diagnostic laparoscopy. The primary study endpoint is progression-free survival. According to the sample size calculation, 155 patients need to be randomized to each treatment arm. Disease recurrence will be documented by scheduled computed tomography scans 9, 12, 15, 21 and thereafter every 6 months until disease progression. For quality control, circumferential resection margins are marked intraoperatively, and representative histological sections will be centrally reviewed by a dedicated pathologist.</p> <p>Discussion</p> <p>The NEOPAC study will determine the efficacy of neoadjuvant chemotherapy in pancreatic cancer for the first time and offers a unique potential for translational research. Furthermore, this trial will provide the unbiased overall survival of all patients undergoing surgery for resectable cancer of the pancreatic head.</p> <p>Trial registration</p> <p>clinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01314027">NCT01314027</a></p
A polymorphism of EGFR extracellular domain is associated with progression free-survival in metastatic colorectal cancer patients receiving cetuximab-based treatment
International audienceBackground: Cetuximab, a monoclonal antibody targeting Epidermal Growth Factor Receptor (EGFR), is currently used in metastatic colorectal cancer (mCRC), but predictive factors for therapeutic response are lacking. Mutational status of KRAS and EGFR, and EGFR copy number are potential determinants of cetuximab activity.Methods: We analyzed tumor tissues from 32 EGFR-positive mCRC patients receiving cetuximab/irinotecan combination and evaluable for treatment response. EGFR copy number was quantified by fluorescence in situ hybridization (FISH). KRAS exon 1 and EGFR exons coding for extracellular regions were sequenced.Results: Nine patients experienced an objective response (partial response) and 23 were considered as nonresponders (12 with stable disease and 11 with progressive disease). There was no EGFR amplification found, but high polysomy was noted in 2 patients, both of which were cetuximab responders. No EGFR mutations were found but a variant of exon 13 (R521K) was observed in 12 patients, 11 of which achieved objective response or stable disease. Progression-free and overall survivals were significantly better in patients with this EGFR exon 13 variant. KRAS mutations were found in 14 cases. While there was a trend for an increased KRAS mutation frequency in nonresponder patients (12 mutations out of 23, 52%) as compared to responder patients (2 out of 9, 22%), authentic tumor response or long-term disease stabilization was found in KRAS mutated patients.Conclusion: This preliminary study suggests that: an increase in EGFR copy number may be associated with cetuximab response but is a rare event in CRC, KRAS mutations are associated with low response rate but do not preclude any cetuximab-based combination efficacy and EGFR exon 13 variant (R521K) may predict for cetuximab benefit
Passive damping of composite blades using embedded piezoelectric modules or shape memory alloy wires: a comparative study
Emission reduction from civil aviation has been intensively addressed in the scientific community in recent years. The combined use of novel aircraft engine architectures such as open rotor engines and lightweight materials offer the potential for fuel savings, which could contribute significantly in reaching gas emissions targets, but suffer from vibration and noise issues. We investigated the potential improvement of mechanical damping of open rotor composite fan blades by comparing two integrated passive damping systems: shape memory alloy wires and piezoelectric shunt circuits. Passive damping concepts were first validated on carbon fibre reinforced epoxy composite plates and then implemented in a 1:5 model of an open rotor blade manufactured by resin transfer moulding (RTM). A two-step process was proposed for the structural integration of the damping devices into a full composite fan blade. Forced vibration measurements of the plates and blade prototypes quantified the efficiency of both approaches, and their related weight penalty
Shape Semantics from Shape Context
Abstract. 3D models play an important role in many industrial applications. Therefore semantic processing for the purposes of comparing, cataloging and archiving shapes is a major concern. Most previous work considers comparisons based on the object’s overall geometry or in a reference frame which is computed from the object’s geometry alone, disregarding its context. There are also approaches which propose to match feature points to perform context alignment to better analyze a single element. In complex assemblies created in a CAD system, however, the parts (components and layers) are often explicitly marked and named and therefore the geometric context is evident. In this paper we show how this can be exploited with the aid of Knowledge Management tools to establish accurate frames of reference where the individual shapes can be better analyzed.
Preoperative percutaneous portal vein embolization: evaluation of adverse events in 188 patients.
PURPOSE: To retrospectively assess the frequency of adverse events related to percutaneous preoperative portal vein embolization (PPVE). MATERIALS AND METHODS: Institutional review board did not require its approval or patient informed consent for this study. The adverse events that occurred during PPVE or until planned hepatic surgery was performed or cancelled were retrospectively obtained from clinical, imaging, and laboratory data files in 188 patients (109 male and 79 female patients; mean age, 60 years; range, 16-78 years). Liver resection was planned for metastases (n = 137), hepatocarcinoma (n = 31), cholangiocarcinoma (n = 15), fibrolamellar hepatoma (n = 1), and benign disease (n = 4). PPVE was performed with a single-lumen 5-F catheter and a contralateral approach with n-butyl cyanoacrylate mixed with iodized oil as the main embolic agent. The rate of complications in patients with cirrhosis was compared with that in patients without cirrhosis by using the chi(2) test. RESULTS: Adverse events occurred in 24 (12.8%) of 188 patients, including 12 complications and 12 incidental imaging findings. Complications included thrombosis of the portal vein feeding the future remnant liver (n = 1); migration of emboli in the portal vein feeding the future remnant liver, which necessitated angioplasty (n = 2); hemoperitoneum (n = 1); rupture of a metastasis in the gallbladder (n = 1); transitory hemobilia (n = 1); and transient liver failure (n = 6). Incidental findings were migration of small emboli in nontargeted portal branches (n = 10) and subcapsular hematoma (n = 2). Among the 187 patients in whom PPVE was technically successful, there was a significant difference (P < .001) between the occurrence of liver failure after PPVE in patients with cirrhosis (five of 30) and those without (one of 157). Sixteen liver resections were cancelled due to cancer progression (n = 12), insufficient hypertrophy of the nonembolized liver (n = 3), and complete portal thrombosis (n = 1). CONCLUSION: PPVE is a safe adjuvant technique for hypertrophy of the initially insufficient liver reserve. Post-PPVE transient liver failure is more common in patients with cirrhosis than in those without cirrhosis
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