Estrogen receptor ß activation impairs mitochondrial oxidative metabolism and affects malignant mesothelioma cell growth in vitro and in vivo.

Estrogen receptor (ER)-ß has been shown to possess a tumor suppressive effect, and is a potential target for cancer therapy. Using gene-expression meta-analysis of human malignant pleural mesothelioma, we identified an ESR2 (ERß coding gene) signature. High ESR2 expression was strongly associated with low succinate dehydrogenase B (SDHB) (which encodes a mitochondrial respiratory chain complex II subunit) expression. We demonstrate that SDHB loss induced ESR2 expression, and that activated ERß, by over-expression or by selective agonist stimulation, negatively affected oxidative phosphorylation compromising mitochondrial complex II and IV activity. This resulted in reduced mitochondrial ATP production, increased glycolysis dependence and impaired cell proliferation. The observed in vitro effects were phenocopied in vivo using a selective ERß agonist in a mesothelioma mouse model. On the whole, our data highlight an unforeseen interaction between ERß-mediated tumor suppression and energy metabolism that may be exploited to improve on the therapy for clinical management of malignant mesothelioma.

Will antiangiogenic agents be a future for mesothelioma therapy?

BACKGROUND: Malignant mesothelioma (MM) is an aggressive disease that is diagnosed mostly in locally advanced or metastatic stage. In this condition chemotherapy with the combination cisplatin and pemetrexed or ralitrexed represents the standard treatment as supported by a phase III study. However, chemotherapy has very limited effect on the improvement of survival of patients and very few of the MM patients survive more than 2 years. A better understanding of molecular mechanisms and pathways involved in angiogenesis in MM is the basis for the development of new drugs targeted against these pathways responsible for the proliferation and survival of tumor cells. OBJECTIVE: This review discusses the role of angiogenic factors in tumourigenesis with a particular focus on MM and it summarizes the results of clinical trials on the drugs targeting angiogenic pathways in MM. METHODS: We have used original research articles, abstracts and oral presentations from ASCO (American Society of Clinical Oncology) and the website of clinical trials http://www.ClinicalTrials.gov. RESULTS/CONCLUSIONS: This review summarizes the results of antiangiogenic agents under evaluation in clinical trials. A better understanding of the angiogenic pathways activated in MM will hopefully provide new therapeutic options for these patients in the future.

Guidelines of the European Respiratory Society and the European Society of Thoracic Surgeons for the management of malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare tumour but with increasing incidence and a poor prognosis. In 2008, the European Respiratory Society/European Society of Thoracic Surgeons Task Force brought together experts to propose practical and up-to-dated guidelines on the management of MPM. To obtain an earlier and reliable diagnosis of MPM, the experts recommend performing thoracoscopy, except in cases of pre-operative contraindication or pleural symphysis. The standard staining procedures are insufficient in approximately 10% of cases. Therefore, we propose using specific immunohistochemistry markers on pleural biopsies. In the absence of a uniform, robust and validated staging system, we advice use of the most recent TNM based classification, and propose a three step pre-treatment assessment. Patient's performance status and histological subtype are currently the only prognostic factors of clinical importance in the management of MPM. Other potential parameters should be recorded at baseline and reported in clinical trials. MPM exhibits a high resistance to chemotherapy and only a few patients are candidates for radical surgery. New therapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach should be included in a prospective trial at a specialised centre.

Taurolidine and oxidative stress: a rationale for local treatment of mesothelioma.

Malignant mesothelioma is an asbestos-related, aggressive tumour, resistant to most anticancer therapies. Akt is a key mediator of mesothelioma cell survival and chemoresistance. This study aimed to clarify the mechanism by which taurolidine (TN), a known synthetic compound with antimicrobial and antineoplastic properties, leads to mesothelioma cell death. Apoptosis was studied by annexin V binding, cell cycle analysis, caspase-8 activation, poly(ADP-ribose) polymerase (PARP) cleavage and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling (TUNEL). Oxidative stress was measured by nitrite production and DNA oxidative damage. Protein expression and phosphorylation were evaluated by immunoprecipitation and immunoblotting. TN induces cell death of mesothelioma cells, but not of non-neoplastic human mesothelial cells. After TN treatment of mesothelioma cells, Akt but not extracellular signal-regulated kinase (Erk) 1/2 activity is inhibited a in time- and dose-dependent manner. Protein phosphatase (PP)1alpha and PP2A are activated several hours after drug addition. Apoptosis induced by TN is driven by oxidative stress and cell exposure to sulfydryl donors, such as glutathione monoethylester and l-N-acetylcysteine, significantly reduced pro-apoptotic effects and Akt inhibition. Conversely, expression of constitutively activated Akt did not affect cytoxicity elicited by TN, which retained its ability to inhibit the kinase. TN induces mesothelioma cell death via oxidative stress, accompanied by inhibition of Akt signalling. This provides a promising molecular rationale for TN as local treatment of malignant mesothelioma.

Hallazgos endoscópicos en pacientes con síntomas cardinales de enfermedad de reflujo gastroesofágico

La enfermedad de reflujo gastroesofágico (ERGE) es una enfermedad recurrente relacionada con el flujo retrógrado del contenido gástrico al esófago, con o sin daño tisular a dicho nivel. La Hernia Hiatal (HH) se asocia con ERGE, y se ha relacionado con grados severos de la enfermedad (Esofagitis Erosiva Severa y Esófago de Barrett). Objetivo: Describir la presencia y las alteraciones a nivel de la mucosa esofágica reportadas endoscópicamente en los pacientes que consultan con síntomas de ERGE al servicio de Gastroenterología del Hospital Vargas. Pacientes y métodos: estudio descriptivo de corte transversal, en el cual se evaluaron hallazgos endoscópicos de pacientes que acudieron con síntomas de ERGE a las consultas del servicio de gastroenteologia del Hospital Vargas entre enero-mayo de 2007. Resultados: de 674 pacientes encuestados, 204 pacientes (59 hombres y 145 mujeres)presentaron síntomas de ERGE, a 60 de ellos se les realizó videogastroscopia de manera aleatoria, reportando 23,33% (14 pacientes) con ERGE erosiva, 1,66% (1paciente) con tu submucoso de esófago, 6,66% con esófago Barret y 75% (45 pacientes) sin alteraciones esofágicas. 23 (38,33%) con hernia hiatal, 8 de ellos con esofagitis erosiva. Conclusiones: Nuestro trabajo confirma el valor de la endoscopia digestiva superior en la evaluación de pacientes con síntomas cardinales de ERGE.

Gastro-esophageal reflux disease (GERD) is a recurrent disease related with retrograde progression of gastric contents to the esophagus with or without mucosal damage at this level. Hiatal hernia is associated with GERD and it has been related with severe grades of the disease (severe erosive esophagitis and BarrettÊs esophagus). Aims: to describe the presence of endoscopic features in GERD patientss with cardinals symptoms attended at the Gastroenterology Division of the Vargas Hospital in Caracas. Patients and Methods: this was a descriptive, transversal cohort study in which endoscopic findings in patients with GERD symptoms were evaluated, at the Gastroenterology Service, between January and May 2007. Results: of 674 patients interviewed, 204 patients (59 men and 145 women) presented GERD symptoms; to 60 of them an upper endoscopy randomly was performed. 23,33% (14 patients) had erosive GERD, 1,66% (1 patient) a submucous esophageal tumor, 6,66 % with BarrettÊs esophagus and 75% (45 patients) without esophageal changes, 23 (38,33%) with hiatal hernia, 8 of them with erosive esophagitis. Conclusion: our study supports the importance of performing an upper endoscopy in patients with cardinals symptoms of GERD.

Experiencia en la colocación de prótesis endoscópica en patología biliopancreática

Desde hace dos décadas esta descrita la utilidad de las prótesis endoscópicas, en patología biliopancreática. Objetivo: Mostrar la experiencia del Servicio de Gastroenterología del Hospital Vargas de Caracas en la colocación de prótesis endoscópicas en la patología biliopancreática, describiendo características demográficas, patologías más frecuentes, tasa de éxito en su colocación y complicaciones. Pacientes y Métodos: Estudio descriptivo, retrospectivo. Se revisaron datos de los informes de CPRE de pacientes hospitalizados y ambulatorios evaluados en la institución desde enero 1998 hasta abril 2007. Resultados: Se incluyeron 248 procedimientos de 110 mujeres y 73 hombres, 242 correspondieron a colocación de prótesis biliares (234 de teflón o plástico y 8 autoexpansibles metálicas) y 6 prótesis pancreáticas. Las indicaciones mas frecuentes para la colocación de prótesis fueron: patologías neoplásicas (47%), lesiones de la vía biliar post-quirúrgicas o traumáticas (22%) y litiasis biliar (17%). El éxito de la colocación de la prótesis fue del 99,1%. Se reportaron complicaciones en 4% de los procedimientos, con mayor frecuencia la colangitis (2%) y una mortalidad del 0%. Conclusión: La colocación de prótesis endoscópicas en patologías biliopancreáticas es un procedimiento seguro, con un bajo porcentaje de complicaciones y mortalidad.

The utility of the endoscopic stent have been described for two decades in the biliopancreatic diseases. Aims: To show the Gastroenterology Division of the Hospital Vargas de Caracas experience in placing endoscopic stents in biliopancreatic diseases, describing demographic characteristics more frequent diseases, success rates and complications. Patients and Methods: descriptive and retrospective trial. Features of the reports of PEPR of hospitalized and ambulatory patients seen in the institution from January 1998 to april 2007 were reviewed. Results: 248 procedures from 110 women and 73 men were included, 242 had a biliar stent (234 of Teflon or plastic and 8 metallic selfexpanded) and 6 had pancreatic stents. The more frequent indications for placing the stents were: Tumoral disease, (47%), traumatic or post-surgical lesions of the biliary tract (22%) and biliary stones (17%). The success rate of the placing of stents was 99.1%. The procedureÊs complication rate reported was 4%, being colangitis the most frequent with 2% and a 0% mortality. Conclusion: the placing of endoscopic stents in biliopancreatic diseases is a safe procedure, with a low rate of complications and mortality.

Prevalencia de enfermedad por reflujo gastroesofágico en población adulta del área metropolitana de Caracas Venezuela

La enfermedad por reflujo gastroesofágico (ERGE) es uno de los trastornos gastrointestinales con mayor prevalencia; afecta del 10 a 15% de la población general constituyendo una causa frecuente de consulta. Sin embargo, existen pocos reportes acerca de la prevalencia de ERGE en la población general. Objetivos: Determinar la prevalencia de ERGE en la población general adulta del área metropolitana de Caracas y estudiar algunos factores asociados a esta enfermedad. Materiales y métodos: Estudio de corte transversal, realizado en la población general adulta del área metropolitana de Caracas en abril de 2007. Se utilizó una encuesta basada en criterios clínicos epidemiológicos de acuerdo a consensos latinoamericanos y europeos sobre la ERGE. Para el análisis de los resultados se calcularon promedios, medianas y porcentajes. Resultados: De 389 sujetos encuestados, 223 fueron mujeres (57,3%) y 166 hombres (42,7%). El promedio de edad fue 33,89 años. La prevalencia de síntomas cardinales en la ERGE fue 19,02%. En los sujetos con ERGE encontramos que 47,3% ingerían licor al menos un vez al mes, y 21,6% referían hábitos tabáquicos. Conclusión: Se determinó que la prevalencia de la ERGE en la población general adulta del área Metropolitana de Caracas fue de 19,02% encontrándose asociación con el hábito alcohólico.

Gastroesophageal reflux disease (GERD) is one of the gastrointestinals problems with higher prevalence; it affects 10 to 15% of the general population being a frequent cause of medical visit. Nevertheless, there is low number of reports about GERD prevalence. Objectives: to determine GERD prevalence in adult population of the Caracas Metropolitan Area and study some related factors to this disease. Materials and methods: Study of transversal cut, made in adult population in Caracas Metropolitan Area in April 2007. A poll based in clinical and epidemiological criteria in accordance with a Latin- American and European consensus about GERD was used. To analize the results averages, medians and percentages were calculated. Results: of 389 subjects surveyed, 223 were women (57,3%) and 166 were men (42,7%). The mean age of the patients was 33 years old. The cardinals symptoms prevalence was 19,02%. In subjects with GERD we found that 47,3% drank alcohol at least once a week, and 21,6% were smokers. In Conclusion, we found that GERD prevalence in adult population of the Caracas Metropolitan Area was 19, 02% finding a relationship with alcoholic habit.

BCL-2 family regulation by the 20S proteasome inhibitor bortezomib.

Bortezomib (Velcade, PS341) was licensed in 2003 as a first-in-class 20S proteasome inhibitor indicated for treatment of multiple myeloma, and is currently being evaluated clinically in a range of solid tumours. The mechanisms underlying its cancer cell toxicity are complex. A growing body of evidence suggests proteasome inhibition-dependent regulation of the BCL-2 family is a critical requirement. In particular, the stabilization of BH3-only proteins BIK, NOXA and BIM, appear to be essential for effecting BAX- and BAK-dependent cell death. These mechanisms are reviewed and the implications for favourable novel drug interactions are highlighted.

Rendimiento diagnóstico de la cápsula endoscópica y enteroscopia doble balón en pacientes con hemorragia digestiva oscura

Introducción: los métodos descritos para el estudio del intestino delgado han sido de difícil realización y baja certeza diagnóstica. La cápsula endoscópica (CE) y enteroscopia doble balón (EDB), permiten obtener beneficio para el estudio y tratamiento del paciente con hemorragia digestiva oscura. Objetivo: determinar el rendimiento diagnóstico de la CE y EDB en pacientes con hemorragia digestiva oscura. Métodos y pacientes: se evaluaron 50 pacientes con hemorragia digestiva oscura, en 24 pacientes se realizó CE y en 26 pacientes EDB. Los hallazgos de las lesiones por cápsula endoscópica M2A Given Imaging y enteroscopia doble balón fueron comparados. Resultados: como causa de sangrado se encontraron lesiones en el 56,52% de los pacientes utilizando CE y en 42,30 % de los pacientes con EDB (p= 0,04). Ambos estudios fueron bien tolerados. No se reportó ningún efecto adverso. Biopsias (n: 1), coagulación con argón plasma (n: 7), esclerosis con adrenalina (n: 1) fueron realizados al utilizar EDB. Conclusión: el rendimiento diagnóstico de la CE y EDB fue similar para detectar las lesiones causantes de hemorragia oscura. La ventaja de la EDB es la posibilidad de aplicar procedimientos endoscópicos terapéuticos.

Introduction: The methods described for the study of the small bowel have been of difficult accomplishment and low diagnostic certainty. The Endoscopic Capsule (EC) and Double Balloon Enteroscopy (DBE), can be helpful in the study and treatment of the patient with occult digestive bleeding. Objective: To determine the diagnostic yield of EC and DBE in patients with occult digestive bleeding. Methods and patients: 50 patients with occult digestive bleeding were evaluated, in 24 patients EC was the method of choice and in 26 patients DBE. Findings by means of endoscopic capsule M2A Given Imaging and double balloon enteroscopy were compared. Results: A cause of bleeding was found in 56.52% of patients using EC and in 42, 30% of patients with DBE (p=0,04). Both studies were well tolerated. No adverse effects were reported. Biopsies (n: 1), argon plasma coagulation (n: 7), sclerosis with adrenalin (n: 1) were performed when using DBE. Conclusion: The diagnostic yield of EC and DBE was similar in detecting injuries causing occult bleeding. The advantage of DBE is the possibility of applying therapeutic endoscopic procedures.

Cápsula endoscópica y enteroscopia doble balón en pacientes con patología del intestino delgado

Introducción: La cápsula endoscópica (CE) y la enteroscopia de doble balón (EDB) fueron introducidas como nuevas modalidades endoscópicas para el estudio del intestino delgado. Objetivo: comparar el rendimiento diagnóstico de estos dos métodos en la evaluación de pacientes con patología del intestino delgado. Pacientes y métodos: estudio descriptivo de una muestra de 97 pacientes de ambos géneros mayores de 12 años, que acudieron al Servicio de Gastroenterología del Hospital Vargas de Caracas y Policlínica Metropolitana entre diciembre 2004 y mayo 2006, con indicación médica para evaluación del intestino delgado por cápsula endoscópica y/o enteroscopia doble balón. Resultados: a 30 pacientes se les realizó CE (12 mujeres, 18 hombres) edad promedio 58,95 años. Se encontraron hallazgos positivos en 72,41%. A 67 pacientes (36 mujeres, 31 hombres) se les realizó enteroscopia doble balón, edad promedio de 52,9 años. Hubo hallazgos positivos en 62,68%. Hubo 3 complicaciones menores (4,4%) tratadas médicamente. Conclusión: el rendimiento diagnóstico de la CE y EDB fue similar para detectar lesiones del intestino delgado. EDB permite realizar toma de biopsias y procedimientos terapéuticos.

Introduction: Endoscopic Capsule (EC) and Double Balloon Enteroscopy (DBE), are new endoscopic modalities for the study of the small bowel. Objective: To compare the diagnostic yield of these two methods in the evaluation of patients with pathology of the small bowel. Patients and methods: Comparative study of a sample of 97 patients of both genders that attended the Hospital Vargas de Caracas and Metropolitan Policlinic, between December 2004-May 2006, with clinical indication for evaluation of the small bowel by EC and/or DBE. Results: EC was performed to 30 patients (12 women, 18 men) age average 58,95 years, with findings in 72,41%: DBE was performed to 67 patients (36 women, 31 men), age average 52,9 years. Positive findings: 62,68%. There were 3 complications (4,4%).Conclusion: The diagnostic yield of EC y DBE was similar to detect lesions of the small bowel. With DBE is possible to take biopsy samples and perform therapeutic procedures.

Erionite and asbestos differently cause transformation of human mesothelial cells.

Malignant mesothelioma (MM) is an aggressive tumor associated with environmental or occupational exposure to asbestos fibers. Erionite is a fibrous zeolite, morphologically similar to asbestos and it is assumed to be even more carcinogenic. Onset and progression of MM has been suggested as the result of the cooperation between asbestos and other cofactors, such as SV40 virus infection. Nevertheless, several cases of MM were associated with environmental exposure to erionite in Turkey, where SV40 was never isolated in MM specimens. We show here that erionite is poorly cytotoxic, induces proliferating signals and high growth rate in human mesothelial cells (HMC). Long term exposure to erionite, but not to asbestos fibers, transforms HMC in vitro, regardless of the presence of SV40 sequences, leading to foci formation in cultured monolayers. Cells derived from foci display constitutive activation of Akt, NF-kappaB and Erk1/2, show prolonged survival and a deregulated cell cycle, involving cyclin D1 and E overexpression. Our results reveal that erionite is able per se to turn HMC into transformed highly proliferating cells and disclose the carcinogenic properties of erionite, prompting for a careful evaluation of environmental exposure to these fibers. The genetic predisposition to the effect of erionite is a separate subject for investigation.

[Evaluation of a series of serum mesothelin in patients with pleural malignant mesothelioma]. / Valutazione di dosaggi seriati di mesotelina sierica in pazienti affetti da mesotelioma maligno della pleura.

Pleural Malignant Mesothelioma (MM) is a highly aggressive neoplasm with a poor survival rate, hard diagnosis and treatment. The incidence of MM in Western Europe countries is expected to increase drammatically in the next 10-15 years. In spite of this drammatic scenario, at this time the only instruments for screening and early diagnosis are based on radiological tests with evident ethical and economical problems. For this reason, some authors are evaluating biological indicators with the significance of screening and early diagnosis markers. One of the most promising marker is serum mesothelin (SMRP). SMRP levels appeares to be significantly related to MM and its clinical (diagnostic/prognostic) usefulnes has been suggested. The purpose of this research is to show SMRP trend in relation both to the course of the disease and the response to therapies in some Epithelioid MM patients. The analysis of SMRP levels in these patients suggests that it may be a useful marker for monitoring the response to treatment. In fact, it was observed that SMRP increases in patients who did not respond to therapy, it tends to remain stable when therapies results into a clinical stabilization, while it decreases after surgical procedure and in case of clinical improvement.

[Serum mesothelin dosages in follow-up of previously exposed workers]. / Il dosaggio della mesotelina sierica nel follow-up dei lavoratori ex esposti ad amianto.

High dosages of Serum Mesothelin have been demonstrated to be significantly associated to Pleural Malignant Mesothelioma. We recently demonstrated that Serum Mesothelin may be clinically helpful both for diagnostic and prognostic purposes, with the best cut-off corresponding to 1 nM. We also discovered that high levels of Serum Mesothelin are significantly associated to Lung Cancer. The usefulness of this marker in secondary prevention has been suggested, though never demonstrated. We therefore started a long-term prospective cohort study including previously asbestos-exposed workers. These subjects periodically underwent both radiological tests and serum mesothelin dosages. As a mid-term goal of this longitudinal study we decided to check the variability of mesothelin dosages, comparing baseline and follow-up values, as well as the possible correlation with age, duration of exposure, smoking, any abnormality of respiratory functional tests (RFT) and/or radiological tests. At baseline, Mesothelin mean value was 0.66 +/- 0.4 (range 0.08-2.2 nM). Both age (p = 0.04) and abnormal thoracic TC (p = 0.04) were significantly correlated with increased serum mesothelin levels and increasing age. No association was found between baseline mesothelin levels and duration of asbestos exposure (p = 0.5), smoking habits (p = 0.2), abnormal RFT, DLCO (carbon monoxide diffusing capacity) or thoracic X-ray. No significant variation was observed between mesothelin values at baseline and at follow-up (p = 0.2).

Current treatment options and biology of peritoneal mesothelioma: meeting summary of the first NIH peritoneal mesothelioma conference.

Peritoneal mesothelioma is a rare cancer of the peritoneum with about 250 new cases diagnosed each year in the United States. It is the second most common site for mesothelioma development and accounts for 10-20% of all mesotheliomas diagnosed in the United States. A meeting sponsored by the NIH Office of Rare Diseases was held in Bethesda, Maryland on September 13 and 14, 2004. The objective of this meeting was to review the epidemiology, biology and current surgical and medical management of peritoneal mesothelioma. In addition, the meeting also discussed clinical and pre-clinical evaluation of novel treatments for mesothelioma as well as ongoing laboratory research to better understand this disease. This report summarizes the proceedings of the meeting as well as directions for future clinical and basic research.

Malignant mesothelioma in 2004: How advanced technology and new drugs are changing the perspectives of mesothelioma patients. Highlights from the VIIth Meeting of the International Mesothelioma Interest Group.

Malignant mesothelioma (MMe) is a seemingly uncommon tumour whose incidence has in fact increased steadily and progressively over the last 30 years. Indeed, an actual "epidemic" is expected in the next 20 years, with over 1300 new cases a year till 2020 at least. Despite unquestionable improvement in the diagnostic methods at our disposal and the availability of new treatment strategies, the prognosis of MMe patients remains dramatically poor. For all the above reasons, translational research is the key to success; indeed, ever increasing knowledge of the molecular mechanisms underlying MMe pathogenesis could lead (and is actually leading) to new, hopefully more active, treatment options. To foster discussion among investigators working in this field, and to exchange different viewpoints concerning the newest advances in MMe pathogenesis and treatment, the VII International Mesothelioma Interest Group (IMIG) meeting was held in Brescia (Italy) between 24 and 26 June 2004 in cooperation with the Italian Group for the Study and Therapy of MMe (GIMe). The aim of this report is to summarize the most significant advances in the different disciplines applied to MMe presented and discussed during the IMIG meeting and how these advances will be changing the perspective of patients with MMe.

Expression of glycoprotein 90K in human malignant pleural mesothelioma: correlation with patient survival.

The expression of the tumour-associated glycoprotein 90K in patients with malignant pleural mesothelioma (MM) has not been described. This study used enzyme-linked immunoassay (ELISA) to measure 90K in pleural effusions (PEs) and sera from patients with MM (n=28), lung cancer (LC) (n=14) and benign pleural disease (BPD) (n=15). Immunohistochemistry was used to investigate 90K expression in MM and LC tissue sections. The expression of 90K was further evaluated in vitro by ELISA and western blot analysis of conditioned media and cellular extracts of MM, LC and normal human mesothelial (NHM) cell cultures. Finally, the relationships between 90K expression in MM and patient age and survival were studied. The mean 90K level was significantly higher (p<0.05) in PEs of MM patients (11.0+/-6.6 microg/ml) than in LC (6.1+/-3.2 microg/ml) or BPD (6.2+/-5.0 microg/ml) patients. Immunohistochemistry showed a positive reaction for 90K in MM biopsy sections and positive staining limited to inflammatory infiltrates in LC sections. The level of 90K was significantly higher in cell culture media of MM than of LC or NHM (p<0.001). Bands representing proteins with molecular weight of approximately 90 kDa were detected by western blot in MM cellular extracts. An inverse correlation between PE 90K levels and MM patient age (r=-0.45; p=0.017) and a positive correlation between serum 90K levels and MM patient survival (r=0.62; p=0.006) were detected by linear regression analysis. Kaplan-Meier univariate analysis showed increased survival probability for MM patients with serum 90K level >7.3 microg/ml (log rank, p<0.05). This is the first report in MM of the expression of 90K and of its potential diagnostic and prognostic application.

Cancer testis antigens expression in mesothelioma: role of DNA methylation and bioimmunotherapeutic implications.

Recent evidences suggest that malignant mesothelioma may be sensitive to immunotherapy; however, little is known about malignant mesothelioma-associated tumour antigens. Focusing on cancer/testis antigens, the expression of well-characterised immunogenic tumour-associated antigens was investigated in malignant mesothelioma cells. At variance with MAGE-4 and NY-ESO-1, malignant mesothelioma cells frequently expressed MAGE-1, -2 and -3, GAGE 1-2, GAGE 1-6, SSX-2 and SSX 1-5, and distinct malignant mesothelioma cells concomitantly expressed at least four cancer/testis antigens. Additionally, the tumour-associated antigens RAGE-1 was expressed at high levels in both benign and malignant mesothelial cells. Lastly, treatment with the DNA hypomethylating agent 5-aza-2'-deoxycytidine induced and up-regulated the expression of the cancer/testis antigen examined in malignant mesothelioma cells. Overall, these findings strongly suggest that cancer/testis antigens-based immunotherapy may represent a suitable therapeutic approach to malignant mesothelioma, and foresee the clinical use of 5-aza-2'-deoxycytidine to design new chemo-immunotherapeutic strategies in malignant mesothelioma patients.

SV40 replication in human mesothelial cells induces HGF/Met receptor activation: a model for viral-related carcinogenesis of human malignant mesothelioma.

Recent studies suggested that simian virus 40 (SV40) may cause malignant mesothelioma, although the pathogenic mechanism is unclear. We found that in SV40-positive malignant mesothelioma cells, the hepatocyte growth factor (HGF) receptor (Met) was activated. In human mesothelial cells (HMC) transfected with full-length SV40 DNA (SV40-HMC), Met receptor activation was associated with S-phase entry, acquisition of a fibroblastoid morphology, and the assembly of viral particles. Coculture experiments revealed the ability of SV40-HMC to infect permissive monkey cells (CV-1), HMC, and murine BNL CL cells. Cocultured human and murine SV40-positive cells expressed HGF, showed Met tyrosine phosphorylation and S-phase entry, and acquired a spindle-shaped morphology (spBNL), whereas CV-1 cells were lysed. Cocultured HMC inherited from SV40-HMC the infectivity, as they induced lysis in cocultured CV-1 cells. Treatment with suramin or HGF-blocking antibodies inhibited Met tyrosine phosphorylation in all large T antigen (Tag)-positive cells and reverted the spindle-shaped morphology of spBNL. This finding indicated that Met activation and subsequent biological effects were mediated by an autocrine HGF circuit. This, in turn, was causally related to Tag expression, being induced by transfection with the SV40 early region alone. Our findings suggest that when SV40 infects HMC it causes Met activation via an autocrine loop. Furthermore, SV40 replicates in HMC and infects the adjacent HMC, inducing an HGF-dependent Met activation and cell-cycle progression into S phase. This may explain how a limited number of SV40-positive cells may be sufficient to direct noninfected HMC toward malignant transformation.

Basic fibroblast growth factor in mesothelioma pleural effusions: correlation with patient survival and angiogenesis.

The expression of angiogenic factors may represent useful markers for diagnosis and prediction of disease outcome. Basic fibroblast growth factor (b-FGF) is a potent angiogenic factor which promotes in vitro growth of endothelial cells and in vivo vessel formation. We investigated the expression of b-FGF in patients affected with malignant and non-malignant pleural diseases and presenting clinically with non-specific signs and symptoms. We also studied the relationships between the expression of b-FGF in patients with malignant pleural mesothelioma (MM) and tumour aggressiveness, assessed as tumour vessel density (TVD), or patient survival. Basic-FGF was measured by immunoassay in the serum and pleural effusions (PE) of 37 patients. Of these, MM was diagnosed in 15/37 patients while the remaining patients had either peripheral lung adenocarcinoma (PLA) or benign inflammatory pleural disease (BPD). The mean b-FGF level measured 8.5+/-6.1 pg/ml in the PE of the malignant group (MM + PLA) and 23.9+/-19.8 in the PE of the non-malignant group (BPD) (p=0.001). The mean b-FGF level was significantly lower in the PE of MM patients (6.9+/-5.2 pg/ml) compared to BPD patients (p=0.004). Linear regression analysis showed a significant inverse correlation (r=-0.59; p=0.041) between b-FGF levels found in MM PE and patient survival. A noteworthy relationship between high serum b-FGF levels and reduced survival was also observed (r=-0.57; p=0.052). Interestingly, both serum (r=0.48; p=0.114) and PE (r=0.26; p=0.413) b-FGF levels in MM patients correlated poorly with TVD. Our data indicate that b-FGF is significantly more expressed in non-malignant compared to malignant PE, this difference being particularly evident between MM and BPD. Our results also suggest that high b-FGF levels correlate with poor MM patient survival through mechanisms which may be independent of b-FGF angiogenic potential.