Characterization of human pancreatic orthotopic tumor xenografts suitable for drug screening

Background Efforts to identify novel therapeutic options for human pancreatic ductal adenocarcinoma (PDAC) have failed to result in a clear improvement in patient survival to date. Pancreatic cancer requires efficient therapies that must be designed and assayed in preclinical models with improved predictor ability. Among the available preclinical models, the orthotopic approach fits with this expectation, but its use is still occasional. Methods An in vivo platform of 11 orthotopic tumor xenografts has been generated by direct implantation of fresh surgical material. In addition, a frozen tumorgraft bank has been created, ensuring future model recovery and tumor tissue availability. Results Tissue microarray studies allow showing a high degree of original histology preservation and maintenance of protein expression patterns through passages. The models display stable growth kinetics and characteristic metastatic behavior. Moreover, the molecular diversity may facilitate the identification of tumor subtypes and comparison of drug responses that complement or confirm information obtained with other preclinical models. Conclusions This panel represents a useful preclinical tool for testing new agents and treatment protocols and for further exploration of the biological basis of drug responses.

Concentrative nucleoside transporter 1 (hCNT1) promotes phenotypic changes relevant to tumor biology in a translocation independent manner

Nucleoside transporters (NTs) mediate the uptake of nucleosides and nucleobases across the plasma membrane, mostly for salvage purposes. The canonical NTs belong to two gene families, SLC29 and SLC28. The former encode equilibrative nucleoside transporter proteins (ENTs), which mediate the facilitative diffusion of natural nucleosides with broad selectivity, whereas the latter encode concentrative nucleoside transporters (CNTs), which are sodium-coupled and show high affinity for substrates with variable selectivity. These proteins are expressed in most cell types, exhibiting apparent functional redundancy. This might indicate that CNTs play specific roles in the physiology of the cell beyond nucleoside salvage. Here, we addressed this possibility using adenoviral vectors to restore tumor cell expression of hCNT1 or a polymorphic variant (hCNT1S546P) lacking nucleoside translocation ability. We found that hCNT1 restoration in pancreatic cancer cells significantly altered cell-cycle progression and phosphorylation status of key signal-transducing kinases, promoted poly-(ADP ribose) polymerase hyperactivation and cell death, and reduced tumor growth and cell migration. Importantly, the translocation-defective transporter triggered these same effects on cell physiology. These data predict a novel and totally unexpected biological role for the nucleoside transporter protein hCNT1 that appears to be independent of its role as mediator of nucleoside uptake by cells, thereby suggesting a transceptor function. Cell Death & Disease Anastasis Stephanou Receiving Editor Cell Death & Disease 19th Apr 2013 Dr Perez-Torras Av/ Diagonal 643. Edif. Prevosti, Pl -1 Barcelona 08028 Spain RE: Manuscript CDDIS-13-0136R, 'CDDIS-13-0136R' Dear Dr Perez-Torras, It is a pleasure to inform you that your manuscript has been evaluated at the editorial level and has now been officially accepted for publication in Cell Death & Disease, pending you meet the following editorial requirements: 1) the list of the abbreviations is missing please include Could you send us the revised text as word file via e-mail and we will proceed and transfer the paper onto our typesetters. Please download, print, sign, and return the Licence to Publish Form using the link below. This must be returned via FAX to ++ 39 06 7259 6977 before your manuscript can be published:

GD3 Synthase Overexpression Sensitizes Hepatocarcinoma Cells to Hypoxia and Reduces Tumor Growth by Suppressing the cSrc/NF-κB Survival Pathway

Abstract Background: Hypoxia-mediated HIF-1a stabilization and NF-kB activation play a key role in carcinogenesis by fostering cancer cell survival, angiogenesis and tumor invasion. Gangliosides are integral components of biological membranes with an increasingly recognized role as signaling intermediates. In particular, ganglioside GD3 has been characterized as a proapoptotic lipid effector by promoting cell death signaling and suppression of survival pathways. Thus, our aim was to analyze the role of GD3 in hypoxia susceptibility of hepatocarcinoma cells and in vivo tumor growth. Methodology/Principal Findings: We generated and characterized a human hepatocarcinoma cell line stably expressing GD3 synthase (Hep3B-GD3), which catalyzes the synthesis of GD3 from GM3. Despite increased GD3 levels (2-3 fold), no significant changes in cell morphology or growth were observed in Hep3B-GD3 cells compared to wild type Hep3B cells under normoxia. However, exposure of Hep3B-GD3 cells to hypoxia (2% O2) enhanced reactive oxygen species (ROS) generation, resulting in decreased cell survival, with similar findings observed in Hep3B cells exposed to increasing doses of exogenous GD3. In addition, hypoxia-induced c-Src phosphorylation at tyrosine residues, NF-kB activation and subsequent expression of Mn-SOD were observed in Hep3B cells but not in Hep3B-GD3 cells. Moreover, MnTBAP, an antioxidant with predominant SOD mimetic activity, reduced ROS generation, protecting Hep3B-GD3 cells from hypoxia-induced death. Finally, lower tumor growth, higher cell death and reduced Mn-SOD expression were observed in Hep3B-GD3 compared to Hep3B tumor xenografts. Conclusion: These findings underscore a role for GD3 in hypoxia susceptibility by disabling the c-Src/NF-kB survival pathway resulting in lower Mn-SOD expression, which may be of relevance in hepatocellular carcinoma therapy.

Mid-gut ACTH-secreting neuroendocrine tumor unmasked with (18)F-dihydroxyphenylalanine-positron emission tomography.

Ectopic ACTH Cushing's syndrome (EAS) is often caused by neuroendocrine tumors (NETs) of lungs, pancreas, thymus, and other less frequent locations. Localizing the source of ACTH can be challenging. A 64-year-old man presented with rapidly progressing fatigue, muscular weakness, and dyspnea. He was in poor condition and showed facial redness, proximal amyotrophy, and bruises. Laboratory disclosed hypokalemia, metabolic alkalosis, and markedly elevated ACTH and cortisol levels. Pituitary was normal on magnetic resonance imaging (MRI), and bilateral inferior petrosal sinus blood sampling with corticotropin-releasing hormone stimulation showed no significant central-to-periphery gradient of ACTH. Head and neck, thoracic and abdominal computerized tomography (CT), MRI, somatostatin receptor scintigraphy (SSRS), and (18)F-deoxyglucose-positron emission tomography (FDG-PET) failed to identify the primary tumor. (18)F-dihydroxyphenylalanine (F-DOPA)-PET/CT unveiled a 20-mm nodule in the jejunum and a metastatic lymph node. Segmental jejunum resection showed two adjacent NETs, measuring 2.0 and 0.5 cm with a peritoneal metastasis. The largest tumor expressed ACTH in 30% of cells. Following surgery, after a transient adrenal insufficiency, ACTH and cortisol levels returned to normal values and remain normal over a follow-up of 26 months. Small mid-gut NETs are difficult to localize on CT or MRI, and require metabolic imaging. Owing to low mitotic activity, NETs are generally poor candidates for FDG-PET, whereas SSRS shows poor sensitivity in EAS due to intrinsically low tumor concentration of type-2 somatostatin receptors (SST2) or to receptor down regulation by excess cortisol. However, F-DOPA-PET, which is related to amine precursor uptake by NETs, has been reported to have high positive predictive value for occult EAS despite low sensitivity, and constitutes a useful alternative to more conventional methods of tumor localization. LEARNING POINTS: Uncontrolled high cortisol levels in EAS can be lethal if untreated.Surgical excision is the keystone of NETs treatment, thus tumor localization is crucial.Most cases of EAS are caused by NETs, which are located mainly in the lungs. However, small gut NETs are elusive to conventional imaging and require metabolic imaging for detection.FDG-PET, based on tumor high metabolic rate, may not detect NETs that have low mitotic activity. SSRS may also fail, due to absent or low concentration of SST2, which may be down regulated by excess cortisol.F-DOPA-PET, based on amine-precursor uptake, can be a useful method to localize the occult source of ACTH in EAS when other methods have failed.

Clear Cell Papillary Renal Cell Carcinoma and Renal Angiomyoadenomatous Tumor: Two Variants of a Morphologic, Immunohistochemical, and Genetic Distinct Entity of Renal Cell Carcinoma.

Clear cell papillary renal cell carcinoma (ccpRCC) and renal angiomyoadenomatous tumor (RAT) share morphologic similarities with clear cell (ccRCC) and papillary RCC (pRCC). It is a matter of controversy whether their morphologic, immunophenotypic, and molecular features allow the definition of a separate renal carcinoma entity. The aim of our project was to investigate specific renal immunohistochemical biomarkers involved in the hypoxia-inducible factor pathway and mutations in the VHL gene to clarify the relationship between ccpRCC and RAT. We investigated 28 ccpRCC and 9 RAT samples by immunohistochemistry using 25 markers. VHL gene mutations and allele losses were investigated by Sanger sequencing and fluorescence in situ hybridization. Clinical follow-up data were obtained for a subset of the patients. No tumor recurrence or tumor-related death was observed in any of the patients. Immunohistochemistry and molecular analyses led to the reclassification of 3 tumors as ccRCC and TFE3 translocation carcinomas. The immunohistochemical profile of ccpRCC and RAT samples was very similar but not identical, differing from both ccRCC and pRCC. Especially, the parafibromin and hKIM-1 expression exhibited differences in ccpRCC/RAT compared with ccRCC and pRCC. Genetic analysis revealed VHL mutations in 2/27 (7%) and 1/7 (14%) ccpRCC and RAT samples, respectively. Fluorescence in situ hybridization analysis disclosed a 3p loss in 2/20 (10%) ccpRCC samples. ccpRCC and RAT have a specific morphologic and immunohistochemical profile, but they share similarities with the more aggressive renal tumors. On the basis of our results, we regard ccpRCC/RAT as a distinct entity of RCCs.

External Location Factors of Foreign Direct Investment in Russia – Finnish Perspective

Tämän diplomityön tavoitteena on selvittää, mitä alueellisia tekijöitä suomalaiset yritykset ottavat huomioon valitessaan sopivaa sijaintia suoralle investoinnille Venäjän sisällä. Muutamia yrityksen sisäisiä tekijöitä käytetään taustamuuttujina selittämään sijaintitekijöiden painotuksissa havaittavia eroja erilaisten yritysten välillä. Venäjän alueita vertaillaan lopuksi painotusten valossa. Työn ensimmäisessä osassa keskitytään suorien ulkomaisten investointien teoreettiseen taustaan. Aiempia tutkimuksia käydään läpi, jotta tekijät, joilla on havaittu olevan vaikutusta investointien sijoittumiseen maan sisällä, saadaan kartoitettua. Työn jälkimmäinen osa perustuu yrityskyselyn avulla kerättyyn empiiriseen aineistoon. Aineiston avulla selvitetään mitä tekijöitä suomalaisyritykset huomioivat sijaintipäätöstä tehdessään. Tulosten valossa on ilmeistä, että alueen markkinapotentiaali on suomalaisyrityksissä tärkein huomioitava tekijä investoinnin sijainnista päätettäessä. Myös infrastruktuuri ja kustannushyödyt vaikuttavat päätökseen. Erityyppisten yritysten painotukset ovat hyvin samanlaisia. Moskova ja Pietari vastaavat Venäjän alueista parhaiten suomalaisyritysten investoinnin sijainnille asettamia kriteerejä.

Single stage transforaminal retrojugular tumor resection: The spinal keyhole for dumbbell tumors in the cervical spine.

BACKGROUND: Dumbbell tumors are defined as having an intradural and extradural component with an intermediate component within an expanded neural foramen. Complete resection of these lesions in the subaxial cervical spine is a challenge, and it has been achieved through a combined posterior/anterior or anterolateral approach. This study describes a single stage transforaminal retrojugular (TFR) approach for dumbbell tumors resection in the cervical spine. METHODS: This is a retrospective review of a series of 17 patients treated for cervical benign tumors, 4 of which were "true" cervical dumbbell tumors operated by a simplified retrojugular approach. The TFR approach allows a single stage gross total resection of both the extraspinal and intraspinal/intradural components of the tumor, taking advantage of the expanded neural foramen. All patients were followed clinically and radiologically with magnetic resonance imaging (MRI). RESULTS: Gross total resection was confirmed in all four patients by postoperative MRI. Minimal to no bone resection was performed. No fusion procedure was performed and no delayed instability was seen. At follow up, one patient had a persistent mild hand weakness and Horners syndrome following resection of a hemangioblastoma of the C8 nerve root. The other three patients were neurologically normal. CONCLUSIONS: The TFR approach appears to be a feasible surgical option for single stage resection in selective cases of dumbbell tumors of the cervical spine.

Privacy-friendly Business Models for Location-Based Mobile Services

This paper presents a theoretical model to analyze the privacy issues around location based mobile business models. We report the results of an exploratory field experiment in Switzerland that assessed the factors driving user payoff in mobile business. We found that (1) the personal data disclosed has a negative effect on user payoff; (2) the amount of personalization available has a direct and positive effect, as well as a moderating effect on user payoff; (3) the amount of control over user's personal data has a direct and positive effect, as well as a moderating effect on user payoff. The results suggest that privacy protection could be the main value proposition in the B2C mobile market. From our theoretical model we derive a set of guidelines to design a privacy-friendly business model pattern for third-party services. We discuss four examples to show the mobile platform can play a key role in the implementation of these new business models.

Business Model Considerations for Privacy Protection in a Mobile Location Based Context

In this paper we discuss the main privacy issues around mobile business models and we envision new solutions having privacy protection as a main value proposition. We construct a framework to help analyze the situation and assume that a third party is necessary to warrant transactions between mobile users and m-commerce providers. We then use the business model canvas to describe a generic business model pattern for privacy third party services. This pattern is then illustrated in two different variations of a privacy business model, which we call privacy broker and privacy management software. We conclude by giving examples for each business model and by suggesting further directions of investigation

External Location Factors of Finnish Direct Investment in Central and Eastern European Transitional Economies

Tutkimuksen päätavoitteena oli selvittää suomalaisten suorien investointien maan valintaan vaikuttavia tekijöitä Itä- ja Keski-Euroopan kymmenessä siirtymätaloudessa. Empiirisessä osuudessa tarkasteltiin suomalaisten yritysten tärkeimpiä sijaintitekijöitä alueella ja yrityskohtaisten tekijöiden vaikutusta sijaintitekijöihin. Tutkimuksessa selvitettiin myös yritysten päämotiiveja investoida maihin. Laaditun investointikriteeristön mukaan maat pystyttiin laittamaan paremmuusjärjestykseen suomalaisen investoijan kannalta. Empiirisen osuuden aineisto kerättiin postikyselylomakkeella yrityksiltä, joilla on tai jotka ovat suunnittelemassa investointeja näihin maihin. Tutkimusote oli kvantitatiivinen. Tutkimustulokset osoittavat, että suomalaiset investoijat valitsevat Itä- ja Keski-Euroopan maan investointikohteeksi pääasiassa markkinapotentiaalin ja edullisten kustannusten perusteella. Myös infrastruktuuri vaikuttaa maan valintaan. Eri aloilla toimivien yritysten sijaintitekijöiden painotuksissa havaittiin eroja. Yrityksen koko ja päämotiivi vaikuttivat sijaintitekijöiden painotuksiin. Investointikriteereiden mukaan kaksi parasta investointimaata suomalaisille investoijille ovat Puola ja Viro. Vertailtaessa investointikriteereitä toteutuneisiin investointeihin voidaan todeta, että suomalaiset investoijat eivät ole hyödyntäneet investoinneilla saatavia etuja kaikissa kohdemaissa.