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Workshop on immunotherapy combinations. Society for immunotherapy of cancer annual meeting Bethesda, November 3, 2011

Sat, 31 Dec 2011 23:00:00 GMT

Title: Workshop on immunotherapy combinations. Society for immunotherapy of cancer annual meeting Bethesda, November 3, 2011 Author(s) : Martinez-Forero, I. (Iván); Okada, H. (Hideho); Topalian, S.L. (Suzanne L.); Gajewski, T.F. (Thomas F.); Korman, A.J. (Alan J.); Melero, I. (Ignacio) Abstract: Although recent FDA approvals on ipilimumab and sipuleucel-T represent major milestones, the ultimate success of immunotherapy approaches will likely benefit from appropriate combinations with other immunotherapeutic and/or non-immunotherapeutic approaches. However, implementation of ideal combinations in the clinic may still face formidable challenges in regulatory, drug-availability and intellectual property aspects. The 2011 SITC annual meeting hosted a workshop on combination immunotherapy to discuss: 1) the most promising combinations found in the laboratory; 2) early success of combination immunotherapy in clinical trials; 3) industry perspectives on combination approaches, and 4) relevant regulatory issues. The integrated theme was how to accelerate the implementation of efficacious combined immunotherapies for cancer patients. Rodent animal models are providing many examples of synergistic combinations that typically include more than two agents. However, mouse and human immunology differ in a significant number of mechanisms and hence we might be missing opportunities peculiar to humans. Nonetheless, incisive animal experimentation with deep mechanistic insight remains the best compass that we can use to guide our paths in combinatorial immunotherapy. Combination immunotherapy clinical trials are already in progress and preliminary results are extremely promising. As a key to translate promising combinations into clinic, real and “perceived” business and regulatory hurdles were debated. A formidable step forward would be to be able to test combinations of investigational agents prior to individual approval. Taking together the FDA and the industrial perspective on combinatorial immunotherapy, the audience was left with the clear message that this is by no means an impossible task. The general perception is that the road ahead of us is full of combination clinical trials which hopefully will bring clinical benefit to our cancer patients at a fast pace.

Obesidad, inflamación e insulino-resistencia: papel de los ligandos del receptor gp 130

Mon, 31 Dec 2007 23:00:00 GMT

Title: Obesidad, inflamación e insulino-resistencia: papel de los ligandos del receptor gp 130 Author(s) : Marcos-Gomez, B. (Beatriz); Bustos, M. (Matilde); Prieto, J. (Jesús); Martinez, J.A. (José Alfredo); Moreno-Aliaga, M.J. (María Jesús) Abstract: Obesity can be considered as a low grade inflammatory disease, characterized by increased plasma levels of proinflammatory cytokines such as tumoral necrosis factor-a (TNF-a), and acute phase reactant proteins like C-reactive protein. In this context, some cytokines of the interleukin-6 (IL-6) family have been involved in the inflammatory processes associated to obesity. In addition to IL-6, the IL-6 cytokine family includes IL-11, ciliary neurotrophic factor (cntf), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), leukemia inhibitory factor (LIF) y Oncostatin M (OsM). These proteins are also known as gp130 cytokines because all of them exert their action via the glycoprotein 130 (gp130) as a common transducer protein within their functional receptor complexes. However, their role in obesity and related disorders is controversial; thus, whereas some studies have described the involvement of gp130 cytokines in the development of obesity and its related cluster of pathophysiologic conditions like insulin-resistance, fatty liver and cardiovascular diseases, other trials have proposed the gp130 receptor ligands as therapeutic targets in the treatment of obesity and its related disorders. In fact, CNTF treatment has demonstrated to be effective in the reduction of body weight, by promoting the inhibition of food intake and the activation of the energy expenditure, together with an improvement of insulin sensitivity. This review analyzes the potential therapeutic role of some of the gp130 ligands in obesity and related diseases.

Evaluation of monocytes as carriers for armed oncolytic adenoviruses in murine and Syrian hamster models of cancer

Sat, 31 Dec 2011 23:00:00 GMT

Title: Evaluation of monocytes as carriers for armed oncolytic adenoviruses in murine and Syrian hamster models of cancer Author(s) : Buñuales, M. (María); Garcia-Aragoncillo, E. (Eva); Casado, R. (Raquel); Quetglas, J.I. (José Ignacio); Hervas-Stubbs, S. (Sandra); Bortolanza, S. (Sergia); Benavides-Vallbe, C. (Carolina); Ortiz-de-Solorzano, C. (Carlos); Prieto, J. (Jesús); Hernandez-Alcoceba, R. (Rubén) Abstract: Replication-competent (oncolytic) adenoviruses (OAV) can be adapted as vectors for the delivery of therapeutic genes, with the aim of extending the antitumor effect beyond direct cytolysis. Transgene expression using these vectors is usually intense but short-lived, and repeated administrations are hampered by the rapid appearance of neutralizing antibodies (NAbs). We have studied the performance of monocytes as cell carriers to improve transgene expression in cancer models established in athymic mice and immunocompetent Syrian hamsters. Human and hamster monocytic cell lines (MonoMac6 and HM-1, respectively) were loaded with replication-competent adenovirus-expressing luciferase. Intravenous administration of these cells caused a modest increase in transgene expression in tumor xenografts, but this effect was virtually lost in hamsters. In contrast, intratumoral administration of HM-1 cells allowed repeated cycles of expression and achieved partial protection from NAbs in preimmunized hamsters bearing pancreatic tumors. To explore the therapeutic potential of this approach, HM-1 cells were loaded with a hypoxia-inducible OAV expressing the immunostimulatory cytokine interleukin-12 (IL-12). Three cycles of treatment achieved a significant antitumor effect in the hamster model, and transgene expression was detected following each administration, in contrast with the rapid neutralization of the free virus. We propose monocytes as carriers for multiple intratumoral administrations of armed OAVs.

Radiomarcaje y estudios de biodistribución de nanopartículas poliméricas como adyuvantes para la vacunación oftálmica frente a la brucelosis

Mon, 31 Dec 2012 23:00:00 GMT

Title: Radiomarcaje y estudios de biodistribución de nanopartículas poliméricas como adyuvantes para la vacunación oftálmica frente a la brucelosis Author(s) : Sanchez-Martinez, M. (María); Costa-Martins, R. (Raquel) da; Quincoces, G. (Gemma); Gamazo, C. (Carlos); Caicedo, C. (Carlos); Irache, J.M. (Juan Manuel); Peñuelas, I. (Iván) Abstract: Objetivos: Optimizar el radiomarcaje con 99mTc de nanopartículas de Gantrez® manosiladas y cargadas con el antígeno de Brucella Ovis (Man-NP-HS) y llevar a cabo estudios de biodistribución en ratón tras la administración de las nanopartículas por vía ocular. Metodología: Las Man-NP-HS se obtuvieron por el método de desplazamiento de disolvente. Se purificaron, liofilizaron y caracterizaron. A continuación, se marcaron con 74 MBq de 99mTcO4 - previamente reducido con una disolución ácida de cloruro de estaño, trabajando en ausencia de oxígeno y con un pH final de 4. El rendimiento del marcaje se evaluó mediante TLC. Los estudios de biodistribución se llevaron a cabo en ratones tras la administración oftálmica de la formulación y de un control de 99mTcO4 - libre. Para ello, se sacrificaron los animales a las 2 y a las 24 horas tras la administración ocular y se contaron los órganos en un contador gamma. Resultados: Se obtuvo un rendimiento de marcaje superior al 90%. Los estudios de biodistribución de 99mTc-Man-NP-HS permitieron detectar la actividad concentrada en mucosa nasal y ocular y tracto gastrointestinal tanto a las 2 como a las 24 horas, frente a la biodistribución de 99mTcO4 - libre que permaneció concentrado en la piel alrededor del ojo y en tracto gastrointestinal. Conclusión: Los estudios de biodistribución de 99mTc-Man-NP-HS tras administración oftálmica han permitido demostrar su biodistribución en mucosas y tracto gastrointestinal, característica indispensable como sistema de liberación de antígenos a través de mucosa ocular. Esto, junto con su elevada respuesta inmune, efectiva protección y no virulencia, convierte a estas nanopartículas en una vacuna ideal anti Brucelosis.

Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.

Sat, 31 Dec 2011 23:00:00 GMT

Title: Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia. Author(s) : Vilas-Zornoza, A. (Amaya); Aguirre, X. (Xavier); Abizanda, G. (Gloria); Moreno, C. (Cristina); Segura, V. (Víctor); Martino-Rodriguez, A. (Alba) de; San-Jose-Eneriz, E. (Edurne); Miranda, E. (Estibaliz); Martin-Subero, J.I. (José Ignacio); Garate, L. (Leire); Blanco-Prieto, M.J. (María José); Garcia-de-Jalon, J.A. (José A.); Rio, P. (Paula); Rifon, J. (José); Cigudosa, J.C. (Juan Cruz); Martinez-Climent, J.A. (José Angel.); Roman-Gomez, J. (José); Calasanz, M.J. (María José); Ribera, J.M. (José María); Prosper, F. (Felipe) Abstract: Histone deacetylases (HDACs) have been identified as therapeutic targets due to their regulatory function in chromatin structure and organization. Here, we analyzed the therapeutic effect of LBH589, a class I-II HDAC inhibitor, in acute lymphoblastic leukemia (ALL). In vitro, LBH589 induced dose-dependent antiproliferative and apoptotic effects, which were associated with increased H3 and H4 histone acetylation. Intravenous administration of LBH589 in immunodeficient BALB/c-RAG2(-/-)γc(-/-) mice in which human-derived T and B-ALL cell lines were injected induced a significant reduction in tumor growth. Using primary ALL cells, a xenograft model of human leukemia in BALB/c-RAG2(-/-)γc(-/-) mice was established, allowing continuous passages of transplanted cells to several mouse generations. Treatment of mice engrafted with T or B-ALL cells with LBH589 induced an in vivo increase in the acetylation of H3 and H4, which was accompanied with prolonged survival of LBH589-treated mice in comparison with those receiving vincristine and dexamethasone. Notably, the therapeutic efficacy of LBH589 was significantly enhanced in combination with vincristine and dexamethasone. Our results show the therapeutic activity of LBH589 in combination with standard chemotherapy in pre-clinical models of ALL and suggest that this combination may be of clinical value in the treatment of patients with ALL.

Preclinical activity of LBH589 alone or in combination with chemotherapy in a xenogeneic mouse model of human acute lymphoblastic leukemia.

Sat, 31 Dec 2011 23:00:00 GMT

Maintained effectiveness of an electronic alert system to prevent venous thromboembolism among hospitalized patients

Wed, 31 Dec 2008 23:00:00 GMT

Title: Maintained effectiveness of an electronic alert system to prevent venous thromboembolism among hospitalized patients Author(s) : Lecumberri, R. (Ramón); Marques, M. (Margarita); Diaz-Navarlaz, M.T. (María Teresa); Panizo, E. (Elena); Toledo, J. (Jon); Garcia-Mouriz, A. (Alberto); Paramo, J.A. (José Antonio) Abstract: Despite current guidelines, venous thromboembolism (VTE) prophylaxis is underused. Computerized programs to encourage physicians to apply thromboprophylaxis have been shown to be effective in selected populations. Our aim was to analyze the impact of the implementation of a computer-alert system for VTE risk in all hospitalized patients of a teaching hospital. A computer program linked to the clinical record database was developed to assess all hospitalized patients' VTE risk daily. The physician responsible for patients at high risk was alerted, but remained free to order or withhold prophylaxis. Over 19,000 hospitalized, medical and surgical, adult patients between January to June 2005 (pre-intervention phase), January to June 2006 and January to June 2007 (post-intervention phase), were included. During the first semesters of 2006 and 2007, an electronic alert was sent to 32.8% and 32.2% of all hospitalized patients, respectively. Appropriate prophylaxis among alerted patients was ordered in 89.7% (2006) and 88.5% (2007) of surgical patients, and in 49.2% (2006) and 64.4% (2007) of medical patients. A sustained reduction of VTE during hospitalization was achieved, Odds ratio (OR): 0.53, 95% confidence interval (CI) (0.25-1.10) and OR: 0.51, 95%CI (0.24-1.05) during the first semesters of 2006 and 2007 respectively, the impact being significant (p < 0.05) among medical patients in 2007, OR: 0.36, 95%CI (0.12-0.98). The implementation of a computer-alert program helps physicians to assess each patient's thrombotic risk, leading to a better use of thromboprophylaxis, and a reduction in the incidence of VTE among hospitalized patients. For the first time, an intervention aimed to improve VTE prophylaxis shows maintained effectiveness over time.

New therapies for hepatocellular carcinoma

Sat, 31 Dec 2005 23:00:00 GMT

Title: New therapies for hepatocellular carcinoma Author(s) : Avila, M.A. (Matías Antonio); Berasain, C. (Carmen); Sangro, B. (Bruno); Prieto, J. (Jesús) Abstract: Hepatocellular carcinoma (HCC), one of the most common cancers worldwide, is often diagnosed at an advanced stage when most potentially curative therapies such as resection, transplantation or percutaneous and transarterial interventions are of limited efficacy. The fact that HCC is resistant to conventional chemotherapy, and is rarely amenable to radiotherapy, leaves this disease with no effective therapeutic options and a very poor prognosis. Therefore, the development of more effective therapeutic tools and strategies is much needed. HCCs are phenotypically and genetically heterogeneous tumors that commonly emerge on a background of chronic liver disease. However, in spite of this heterogeneity recent insights into the biology of HCC suggest that certain signaling pathways and molecular alterations are likely to play essential roles in HCC development by promoting cell growth and survival. The identification of such mechanisms may open new avenues for the prevention and treatment of HCC through the development of targeted therapies. In this review we will describe the new potential therapeutic targets and clinical developments that have emerged from progress in the knowledge of HCC biology, In addition, recent advances in gene therapy and combined cell and gene therapy, together with new radiotherapy techniques and immunotherapy in patients with HCC will be discussed.

S-adenosylmethionine and methylthioadenosine are antiapoptotic in cultured rat hepatocytes but proapoptotic in human hepatoma cells

Mon, 31 Dec 2001 23:00:00 GMT

Title: S-adenosylmethionine and methylthioadenosine are antiapoptotic in cultured rat hepatocytes but proapoptotic in human hepatoma cells Author(s) : Ansorena, E. (Eduardo); Garcia-Trevijano, E.R. (Elena R.); Martinez-Chantar, M.L. (María L.); Huang, Z.Z. (Zong-Zhi); Chen, L. (Lixin); Mato, J.M. (José M.); Iraburu, M. (María); Lu, S.C. (Shelly C.); Avila, M.A. (Matías A.) Abstract: S-adenosylmethionine (AdoMet) is an essential compound in cellular transmethylation reactions and a precursor of polyamine and glutathione synthesis in the liver. In liver injury, the synthesis of AdoMet is impaired and its availability limited. AdoMet administration attenuates experimental liver damage, improves survival of alcoholic patients with cirrhosis, and prevents experimental hepatocarcinogenesis. Apoptosis contributes to different liver injuries, many of which are protected by AdoMet. The mechanism of AdoMet's hepatoprotective and chemopreventive effects are largely unknown. The effect of AdoMet on okadaic acid (OA)-induced apoptosis was evaluated using primary cultures of rat hepatocytes and human hepatoma cell lines. AdoMet protected rat hepatocytes from OA-induced apoptosis dose dependently. It attenuated mitochondrial cytochrome c release, caspase 3 activation, and poly(ADP-ribose) polymerase cleavage. These effects were independent from AdoMet-dependent glutathione synthesis, and mimicked by 5'-methylthioadenosine (MTA), which is derived from AdoMet. Interestingly, AdoMet and MTA did not protect HuH7 cells from OA-induced apoptosis; conversely both compounds behaved as proapoptotic agents. AdoMet's proapoptotic effect was dose dependent and observed also in HepG2 cells. In conclusion, AdoMet exerts opposing effects on apoptosis in normal versus transformed hepatocytes that could be mediated through its conversion to MTA. These effects may participate in the hepatoprotective and chemopreventive properties of this safe and well-tolerated drug.

Methylthioadenosine (MTA) inhibits melanoma cell proliferation and in vivo tumor growth

Thu, 31 Dec 2009 23:00:00 GMT

Title: Methylthioadenosine (MTA) inhibits melanoma cell proliferation and in vivo tumor growth Author(s) : Andreu-Perez, P. (Pedro); Hernandez-Losa, J. (Javier); Moline, T. (Teresa); Gil, R. (Rosa); Grueso, J. (Judit); Pujol, A. (Anna); Cortes, J. (Javier); Avila, M.A. (Matías Antonio); Recio, J.A. (Juan A.) Abstract: BACKGROUND: Melanoma is the most deadly form of skin cancer without effective treatment. Methylthioadenosine (MTA) is a naturally occurring nucleoside with differential effects on normal and transformed cells. MTA has been widely demonstrated to promote anti-proliferative and pro-apoptotic responses in different cell types. In this study we have assessed the therapeutic potential of MTA in melanoma treatment. METHODS: To investigate the therapeutic potential of MTA we performed in vitro proliferation and viability assays using six different mouse and human melanoma cell lines wild type for RAS and BRAF or harboring different mutations in RAS pathway. We also have tested its therapeutic capabilities in vivo in a xenograft mouse melanoma model and using variety of molecular techniques and tissue culture we investigated its anti-proliferative and pro-apoptotic properties. RESULTS: In vitro experiments showed that MTA treatment inhibited melanoma cell proliferation and viability in a dose dependent manner, where BRAF mutant melanoma cell lines appear to be more sensitive. Importantly, MTA was effective inhibiting in vivo tumor growth. The molecular analysis of tumor samples and in vitro experiments indicated that MTA induces cytostatic rather than pro-apoptotic effects inhibiting the phosphorylation of Akt and S6 ribosomal protein and inducing the down-regulation of cyclin D1. CONCLUSIONS: MTA inhibits melanoma cell proliferation and in vivo tumor growth particularly in BRAF mutant melanoma cells. These data reveal a naturally occurring drug potentially useful for melanoma treatment.

Changes in the heart rate variability in patients with obstructive sleep apnea and its response to acute CPAP treatment

Sat, 31 Dec 2011 23:00:00 GMT

Title: Changes in the heart rate variability in patients with obstructive sleep apnea and its response to acute CPAP treatment Author(s) : Kufoy, E. (Ernesto); Palma, J.A. (José A.); Lopez, J. (Jon); Alegre, M. (Manuel); Urrestarazu, E. (Elena); Artieda, J. (Julio); Iriarte, J. (Jorge) Abstract: Obstructive Sleep Apnea (OSA) is a major risk factor for cardiovascular disease. The goal of this study was to demonstrate whether the use of CPAP produces significant changes in the heart rate or in the heart rate variability of patients with OSA in the first night of treatment and whether gender and obesity play a role in these differences. METHODS: Single-center transversal study including patients with severe OSA corrected with CPAP. Only patients with total correction after CPAP were included. Patients underwent two sleep studies on consecutive nights: the first night a basal study, and the second with CPAP. We also analyzed the heart rate changes and their relationship with CPAP treatment, sleep stages, sex and body mass index. Twenty-minute segments of the ECG were selected from the sleep periods of REM, no-REM and awake. Heart rate (HR) and heart rate variability (HRV) were studied by comparing the R-R interval in the different conditions. We also compared samples from the basal study and CPAP nights. RESULTS: 39 patients (15 females, 24 males) were studied. The mean age was 50.67 years old, the mean AHI was 48.54, and mean body mass index was 33.41 kg/m(2) (31.83 males, 35.95 females). Our results showed that HRV (SDNN) decreased after the use of CPAP during the first night of treatment, especially in non-REM sleep. Gender and obesity did not have any influence on our results. CONCLUSIONS: These findings support that cardiac variability improves as an acute effect, independently of gender or weight, in the first night of CPAP use in severe OSA patients, supporting the idea of continuous use and emphasizing that noncompliance of CPAP treatment should be avoided even if it is just once.

Amniotic membrane as a scaffold for melanocyte transplantation in patients with stable vitiligo

Fri, 31 Dec 2010 23:00:00 GMT

Title: Amniotic membrane as a scaffold for melanocyte transplantation in patients with stable vitiligo Author(s) : Redondo, P. (Pedro); Gimenez-de-Azcarate, A. (Ana); Marques, L. (Laura); Garcia-Guzman, M. (María); Andreu, E.J. (Enrique José); Prosper, F. (Felipe) Abstract: Vitiligo is an acquired skin disease that significantly impacts the quality of life of patients. Medical treatment of vitiligo includes the use of melanocyte transplant, but the results are variable. We have treated 4 patients with either focal or generalized stable vitiligo using a graft of autologous melanocytes' culture on a denuded amniotic membrane (AM). A culture biopsy was obtained in every patient and grown in melanocytes' media for 10-14 days after which cells were transferred to a denuded AM and transplanted into the achromic lesions. Patients were followed for up to 6 months using clinical assessment of achromic lesions. Treated areas ranged between 4 cm(2) and 210.6 cm(2). Response to treatment was excellent in all patients with 90-95% repigmentation success rate. Our results demonstrate that transplantation of autologous melanocytes cultured on AM is a new, simple, and effective treatment for stable vitiligo.

Cortactin (CTTN) overexpression in osteosarcoma correlates with advanced stage and reduced survival

Fri, 31 Dec 2010 23:00:00 GMT

Title: Cortactin (CTTN) overexpression in osteosarcoma correlates with advanced stage and reduced survival Author(s) : Folio, C. (Cecilia); Zalacain, M. (Marta); Zandueta, C. (Carolina); Ormazábal, C. (Cristina); Sierrasesumaga, L. (Luis); San-Julian, M. (Mikel); Rivas, J. (Javier) de las; Toledo, G. (Gemma); Lecanda, F. (Fernando); Patiño, A. (Ana) Abstract: The cortactin (CTTN) gene has been found, by transcriptomic profiling, to be overexpressed in pediatric osteosarcoma. The location of CTTN at 11q13 and the role of cortactin in cytoskeleton restructuring make CTTN of interest as a potential biomarker for osteosarcoma. MATERIALS AND METHODS: Osteoblasts were isolated from 20 high-grade osteosarcomas before chemotherapy, and paired with cell samples from normal tissue, prior to RNA expression analysis on HG-U133A chips (Affymetrix). Semiquantitative CTTN mRNA expression was analyzed by real-time PCR. An osteosarcoma tissue microarray (TMA) containing 233 tissue spots from 48 patients was used for an immunohistochemical (IHC) study of cortactin. RESULTS: Transcriptomic profiling and real-time PCR analysis indicated increased CTTN expression in osteosarcomas (p = 0.001, Student's T test). TMA IHC showed cortactin to be present more frequently and in greater abundance in osteosarcomas than non-tumoral osteoblastic samples (p< 0.006, Mann-Withney test). Analysis of clinical outcomes indicated that overall survival for patients with primary tumors positive for cortactin was significantly lower than that for patients with cortactin negative (or only weakly staining) tumors (p = 0.0278, Log-rank test). CONCLUSIONS: Our preliminary data support the hypothesis that over-expression of cortactin, contained in the 11q13 amplicon, is involved in osteosarcoma carcinogenesis. The potential of cortactin overexpression as a biomarker for osteosarcoma is consolidated.

CDH11 Expression is Associated with Survival in Patients with Osteosarcoma

Mon, 31 Dec 2007 23:00:00 GMT

Title: CDH11 Expression is Associated with Survival in Patients with Osteosarcoma Author(s) : Nakajima, G. (Go); Patiño, A. (Ana); Bruheim, S. (Skjalg); Xi, Y. (Yaguang); San-Julian, M. (Mikel); Lecanda, F. (Fernando); Sierrasesumaga, L. (Luis); Muller, C. (Christoph); Fodstad, O. (Oystein); Ju, J. (Jingfang) Abstract: Previous studies have shown that cadherin-11 (CDH11) may be involved in the metastatic process of osteosarcoma. The correlation of the expression levels of CDH11 in osteosarcoma samples with the risk of disease progression and metastasis was examined. Real time qRT-PCR was used to quantify CDH11 expression in a set of newly established osteosarcoma cell lines, 11 primaries and five metastases, compared to the levels in 12 normal osteoblast cell lines established from healthy bone, and also in a set of 10 snap-frozen osteosarcoma samples. In all cases long term clinical follow-up data was available. The CDH11 expression level decreased gradually from the osteoblast to the primary cell lines (p=0.2184) and further to those established from the tumor metastases (p=0.0275). Importantly, the level of CDH11 expression correlated significantly (p=0.01) with patient survival (Kaplan-Meier survival analysis) in both sample sets (p=0.0128 for the cell lines, p=0.0492 for the biopsies). In conclusion, the results indicate that CDH11 may be useful as a prognostic marker of disease progression and survival in osteosarcoma.

Profiling of chemonaive osteosarcoma and paired-normal cells identifies EBF2 as a mediator of osteoprotegerin inhibition to tumor necrosis factor–related apoptosis-inducing ligand–induced apoptosis

Wed, 31 Dec 2008 23:00:00 GMT

Title: Profiling of chemonaive osteosarcoma and paired-normal cells identifies EBF2 as a mediator of osteoprotegerin inhibition to tumor necrosis factor–related apoptosis-inducing ligand–induced apoptosis Author(s) : Patiño, A. (Ana); Zalacain, M. (Marta); Folio, C. (Cecilia); Zandueta, C. (Carolina); Sierrasesumaga, L. (Luis); San-Julian, M. (Mikel); Toledo, G. (Gemma); Rivas, J. (Javier) de las; Lecanda, F. (Fernando) Abstract: Osteosarcoma is the most prevalent bone tumor in children and adolescents. At present, the mechanisms of initiation, maintenance, and metastasis are poorly understood. The purpose of this study was to identify relevant molecular targets in the pathogenesis of osteosarcoma. EXPERIMENTAL DESIGN: Tumor chemonaive osteoblastic populations and paired control normal osteoblasts were isolated and characterized phenotypically from seven osteosarcoma patients. Global transcriptomic profiling was analyzed by robust microarray analysis. Candidate genes were confirmed by real-time PCR and organized in molecular pathways. EBF2 and osteoprotegerin (OPG) levels were determined by real-time PCR and OPG protein levels were assessed by ELISA. Immunohistochemical analysis was done in a panel of 46 osteosarcoma samples. Silencing of EBF2 was achieved by lentiviral transduction of short hairpin RNA. Apoptosis was determined by caspase-3/7 activity. RESULTS: A robust clustered transcriptomic signature was obtained in osteosarcoma. Transcription factor EBF2, a known functional bone regulator, was among the most significantly overexpressed genes. Immunohistochemical analysis showed that osteosarcoma is expressed in approximately 70% of tumors analyzed. Because EBF2 was shown previously to act as a transcriptional activator of OPG, elevated levels of EBF2 were associated with high OPG protein levels in osteosarcoma samples compared with normal osteoblastic cells. Knockdown of EBF2 led to stunted abrogation of OPG levels and increased sensitivity to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. CONCLUSIONS: These findings suggest that EBF2 represents a novel marker of osteosarcoma. EBF2 up-regulation may be one of the mechanisms involved in the high levels of OPG in osteosarcoma, contributing to decrease TRAIL-induced apoptosis and leading to TRAIL resistance.