Dynamic contrast-enhanced CT for the assessment of tumour response in malignant pleural mesothelioma: a pilot study.

OBJECTIVES: The aim of this pilot study was to investigate the utility of haemodynamic parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT) scans in the assessment of tumour response to treatment in malignant pleural mesothelioma (MPM) patients. METHODS: The patient cohort included nine patients undergoing chemotherapy and five patients on observation. Each patient underwent two DCE-CT scans separated by approximately 2 months. The DCE-CT parameters of tissue blood flow (BF) and tissue blood volume (BV) were obtained within the dynamically imaged tumour. Mean relative changes in tumour DCE-CT parameters between scans were compared between the on-treatment and on-observation cohorts. DCE-CT parameter changes were correlated with relative change in tumour bulk evaluated according to the modified RECIST protocol. RESULTS: Differing trends in relative change in BF and BV between scans were found between the two patient groups (p = 0.19 and p = 0.06 for BF and BV, respectively). No significant rank correlations were found when comparing relative changes in DCE-CT parameters with relative change in tumour bulk. CONCLUSIONS: Differing trends in the relative change of BF and BV between patients on treatment and on observation indicate the potential of DCE-CT for the assessment of pharmacodynamic endpoints with respect to treatment in MPM. A future study with a larger patient cohort and unified treatment regimens should be undertaken to confirm the results of this pilot study. KEY POINTS: • CT-derived haemodynamic parameters show differing trends between malignant pleural mesothelioma patients on treatment and patients off treatment • Changes in haemodynamic parameters do not correlate with changes in tumour bulk as measured according to the modified RECIST protocol • Differing trends across the two patient groups indicate the potential sensitivity of DCE-CT to assess pharmacodynamic endpoints in the treatment of MPM.

Curcumin induces apoptosis and inhibits angiogenesis in murine malignant mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare form of cancer that is associated with asbestos exposure. Unfortunately, current therapies have limited efficacy. Previous studies have indicated that curcumin exerts antiproliferative and antitumor effects, and has low toxicity. The present study aimed to evaluate the anticancer effects of curcumin on the RN5 MPM cell line. The inhibitory effects of curcumin on cell viability were determined using the sulforhodamine B assay. In addition, cell cycle progression was analyzed by propidium iodide (PI) staining and flow cytometry, and curcumin­induced apoptosis was measured by Annexin V/PI double staining. The translocation of apoptosis-inducing factor (AIF) was assessed by western blotting and immunofluorescence, and the expression levels of the phosphoinositide 3-kinase (PI3K)-AKT serine/threonine kinase (Akt)­mammalian target of rapamycin (mTOR) signaling pathway proteins and mitochondria-associated proteins were evaluated by western blotting. In vivo antitumor effects were evaluated in a subcutaneous murine model. Briefly, tumors were harvested from the mice, and immunohistochemistry was conducted to evaluate cell proliferation, apoptosis and angiogenesis. The results indicated that curcumin inhibited RN5 cell viability and induced apoptotic cell death. In addition the findings suggested that curcumin-induced cell apoptosis occurred via the mitochondrial pathway, and caspase­independent and AIF-dependent pathways. Further analysis revealed that curcumin may act as a PI3K-Akt-mTOR signaling pathway inhibitor by downregulating PI3K, p-Akt, p-mTOR and p-p70 ribosomal protein S6 kinase. Furthermore, curcumin inhibited tumor angiogenesis in vivo. In conclusion, curcumin may be potent enough to be developed as a novel therapeutic agent for the treatment of MPM.

Chemo-manipulation of tumor blood vessels by a metal-based anticancer complex enhances antitumor therapy.

Human pleural mesothelioma is an incurable and chemoresistant cancer. Using a nude mouse xenograft model of human pleural mesothelioma, we show that RAPTA-T, a compound undergoing preclinical evaluation, enhances tumor vascular function by decreasing blood vessel tortuosity and dilation, while increasing the coverage of endothelial cells by pericytes and vessel perfusion within tumors. This in turn significantly reduces the interstitial fluid pressure and increases oxygenation in the tumor. Consequently, RAPTA-T pre-treatment followed by the application of cisplatin or liposomal cisplatin (Lipoplatin) leads to increased levels of the cytotoxin in the tumor and enhanced mesothelioma growth inhibition. We demonstrate that the vascular changes induced by RAPTA-T are related, in part, to the inhibition of poly-(ADP-ribose) polymerase 1 (PARP-1) which is associated to tumor vascular stabilization. These findings suggest novel therapeutic implications for RAPTA-T to create conditions for superior drug uptake and efficacy of approved cytotoxic anti-cancer drugs in malignant pleural mesothelioma and potentially other chemoresistant tumors.

Progranulin and granulin-like protein as novel VEGF-independent angiogenic factors derived from human mesothelioma cells.

Malignant mesothelioma is an aggressive tumor arising from the mesothelial cells of serous membranes and is associated with tumor angiogenesis, which is a prerequisite for tumor progression. Vascular endothelial growth factors (VEGFs) including VEGF-A have a crucial role in tumor angiogenesis. However, bevacizumab, a monoclonal antibody to VEGF-A, has recently been reported not to improve the progression-free survival of patients with malignant mesothelioma. Cell culture supernatant contains extracellular components such as serum, which can mask the existence of unknown cell-derived factors in the supernatant and make it difficult to detect the factors by subsequent protein analysis. We tried using serum-free culture for human mesothelioma cell lines, NCI-H28, NCI-H2452 and NCI-H2052, and only NCI-H2052 cells adapted to serum-free culture. We found that serum-free culture supernatant derived from NCI-H2052 cells induces the formation of capillary-like tube structures (tube formation) in three-dimensional culture, in which endothelial cells sandwiched between two layers of collagen or embedded in collagen are incubated with various angiogenic inducers. However, neither neutralization of VEGF-A nor RNA interference of VEGF receptor 2 (VEGFR2) suppressed the supernatant-induced tube formation. Using mass spectrometry, we identified a total of 399 proteins in the supernatant, among which interleukin-8 (IL-8), growth-regulated α-protein, midkine, IL-18, IL-6, hepatoma-derived growth factor, clusterin and granulin (GRN), also known as progranulin (PGRN), were included as a candidate protein inducing angiogenesis. Neutralizing assays and RNA interference showed that PGRN, but not the above seven candidate proteins, caused the supernatant-induced tube formation. We also found that NCI-H28 and NCI-H2452 cells express PGRN. Furthermore, we demonstrate that not only PGRN but also GRN-like protein have an important role in the supernatant-induced tube formation. Thus, mesothelioma-derived GRNs induce VEGF-independent angiogenesis.

[Systemic Treatment of Malignant Pleural Mesothelioma].

Malignant pleural mesothelioma(MPM)is a highly aggressive tumor with a poor prognosis and an increasing incidence worldwide. The only standard first-line chemotherapy for patients with unresectable MPM is cisplatin(CDDP)plus peme- trexed(PEM)(CDDP/PEM), with a median overall survival of about 12months and a median progression-free survival(PFS) of less than 6 months. There are no treatments with proven benefit on survival for relapsed MPM patients. Therefore, novel therapeutic strategies are urgently required. Several molecular pathways involved in MPM have been identified; these include growth factor signaling pathways, cell cycle regulation, apoptosis, and angiogenesis. Fortunately, several agents targeting these processes have yielded promising results in preliminary trials. The addition of vascular endothelial growth factor(VEGF) inhibitor bevacizumab to the standard CDDP/PEM provides a 2.7-month survival benefit. Triple angiokinase inhibitor nintedanib, inhibiting the VEGFR, PDGFR, and FGFR, plus standard chemotherapy demonstrated a significant improvement in median PFS of 3.7 months in the overall study population, and a greater median PFS benefit of 4.0 months in epithelioid MPM. Mesothelin is an attractive target protein expressed on mesothelioma cells. Amatuximab, a chimeric anti-mesothelin antibody, in combination with CDDP/PEM, is currently being tested in randomized, double-blind, placebo-controlled phase II study. Anetumab ravtansine, mesothelin-directed antibody drug conjugate, was evaluated in a randomized trial to compare to vinorelbine in patients with MPM who have high mesothelin expression and have progressed on CDDP/PEM-based first-line chemotherapy. However, anetumab ravtansine was not superior to vinorelbine in primary endpoint of PFS(4.3 months vs 4.5 months). Immune checkpoint blockades have demonstrated promising preclinical and clinical results in several cancer types, and are currently being investigated in clinical trials for MPM patients. PD-L1 expression in tumor tissue of MPM was reported, ranging between 20% and 70%. PD-L1 expression was significantly associated with a worse survival and overexpression was more common in sarcomatoid histology. This review summarizes clinical results for the latest systemic treatments in MPM.

Targeting the vasculature: anti-angiogenic agents for malignant mesothelioma.

INTRODUCTION: Malignant mesothelioma (MM) is an aggressive malignancy of the pleura and other serosal membranes originating from mesothelial cells that, despite decades of research, continues to have limited therapeutic options and is associated with a poor prognosis. Areas covered: MMs induce a strong inflammatory response that is also associated with neoangiogenesis and activation of proangiogenic factors. Given this, several anti-angiogenic agents have been trialled in a variety of malignancies including mesothelioma. Herein we summarise the role of angiogenesis in MM and the current available data targeting these pathways. Expert commentary: The addition of bevacizumab to cisplatin/pemetrexed chemotherapy is currently a therapeutic option with a proven 2.7 month overall survival benefit in fit patients less than 75. Other antiangiogenics such as nintedinib show early promise, although the Phase III trial results are eagerly awaited before this therapy enters treatment paradigms. Beyond this, it is likely that combinations of antiangiogenics with immunotherapies will be investigated in future studies.

Combination of onconase and dihydroartemisinin synergistically suppresses growth and angiogenesis of non-small-cell lung carcinoma and malignant mesothelioma.

Onconase (Onc) is a cytotoxic ribonuclease derived from leopard frog oocytes or early embryos, and has been applied to the treatment of malignant mesothelioma in clinics. Onc also exhibits effective growth suppression of human non-small-cell lung cancer (NSCLC). Artemisinin (Art) and its derivatives are novel antimalarial drugs that exhibit antitumor and antivirus activities. In this study, we investigated the antitumor effects of combinations of Onc and an Art derivative, dihydroartemisinin (DHA), both in vitro and in vivo Isobologram analyses showed synergistic effects on the proliferation of NSCLC cells under the treatment with Onc and DHA. In vivo experiments also showed that the antitumor effect of Onc was markedly enhanced by DHA in mouse xenograft models. No obvious adverse effect was observed after the treatment. The density of microvasculature in the tumor tissues treated with Onc/DHA combination was lower than those treated with Onc or DHA alone. The above results are consistent with the results of the matrigel plug test for angiogenesis suppression using the Onc/DHA combination. These results imply that the anti-angiogenesis effects may make important contributions to the in vivo antitumor effects of the Onc/DHA combination treatment. The Onc/DHA combination therapy may have the potential to become a novel regimen for NSCLC and mesothelioma.

Inhibition of PAI-1 Limits Tumor Angiogenesis Regardless of Angiogenic Stimuli in Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor that secretes various angiogenic factors. The main inhibitor of plasminogen activators, PAI-1 (SERPINE1), has been implicated in tumor progression and angiogenesis, and high PAI-1 expression has been associated with poor prognosis in MPM patients. In this study, we examined the antiangiogenic effects of PAI-1 inhibition in MPM. We administered the PAI-1 inhibitor, SK-216, to orthotopic mouse models in which MPM cells expressing high levels of VEGF (VEGFA) or bFGF (FGF2) were intrapleurally transplanted. SK-216 administration reduced tumor weights and the degree of angiogenesis in intrapleural tumors, irrespective of their angiogenic expression profiles. In addition, a combination of SK-216 and the chemotherapeutic agent cisplatin significantly reduced tumor weights compared with monotherapy, prolonging the survival of animals compared with cisplatin treatment alone. Furthermore, SK-216 inhibited migration and tube formation of cultured human umbilical vein endothelial cells induced by various angiogenic factors known to be secreted by MPM. These findings suggest that PAI-1 inactivation by SK-216 may represent a general strategy for inhibiting angiogenesis, including for the treatment of MPM. Cancer Res; 76(11); 3285-94. ©2016 AACR.

Human malignant mesothelioma is recapitulated in immunocompetent BALB/c mice injected with murine AB cells.

Malignant Mesothelioma is a highly aggressive cancer, which is difficult to diagnose and treat. Here we describe the molecular, cellular and morphological characterization of a syngeneic system consisting of murine AB1, AB12 and AB22 mesothelioma cells injected in immunocompetent BALB/c mice, which allows the study of the interplay of tumor cells with the immune system. Murine mesothelioma cells, like human ones, respond to exogenous High Mobility Group Box 1 protein, a Damage-Associated Molecular Pattern that acts as a chemoattractant for leukocytes and as a proinflammatory mediator. The tumors derived from AB cells are morphologically and histologically similar to human MM tumors, and respond to treatments used for MM patients. Our system largely recapitulates human mesothelioma, and we advocate its use for the study of MM development and treatment.

Imaging of mesothelioma of tunica vaginalis testis.

OBJECTIVES: To describe the imaging findings in a series of patients with mesothelioma of the tunica vaginalis testis. METHODS: We reviewed clinical data, imaging findings and follow-up information in a series of 10 pathology-proven cases of mesothelioma (all had US; 2 had MR) of the tunica vaginalis. RESULTS: A variety of patterns could be observed, the most common (5/10) being a hydrocele with parietal, solid and hypervascular vegetations; one patient had a septated hydrocele with hypervascular walls; one had multiple, solid nodules surrounded by a small, physiological quantity of fluid; one a cystic lesion with thick walls and vegetations compressing the testis; two had a solid paratesticular mass. MR showed multiple small nodules on the surface of the tunica vaginalis in one case and diffuse thickening and vegetations in the other one; lesions had low signal intensity on T2-w images and were hypervascular after contrast injection. CONCLUSIONS: A preoperative diagnosis of mesotheliomas presenting as solid paratesticular masses seems very difficult with imaging. On the contrary, the diagnosis must be considered in patients in whom a hydrocele with parietal vegetations is detected, especially if these show high vascularity. KEY POINTS: Mesotheliomas of the tunica vaginalis are rare, often challenging to diagnose preoperatively. Most common finding is a complex hydrocele with hypervascular parietal vegetations. Septated hydrocele, nodules without hydrocele, a thick-walled paratesticular cyst are less common. Preoperative diagnosis may allow aggressive surgical approach and, possibly, a better prognosis.

Therapies currently in Phase II trials for malignant pleural mesothelioma.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is an aggressive cancer associated with asbestos exposure, whose incidence will peak within the next years. Despite an overall low response rate, the current first-line therapy is represented by combined chemotherapy with cisplatin and antifolate. Moreover, there are no currently approved regimens for relapsed or refractory MPM. Therefore, it is clear how both preclinical and clinical researches aimed at identifying new therapeutic targets and testing them in early clinical settings are badly needed. AREAS COVERED: The aim of this review is to summarize and critically comment the ongoing Phase II trials for MPM. EXPERT OPINION: Over the past few years, there has been a significant endeavor of addressing the clinical research for MPM beyond the very modest results of chemotherapy. Nonetheless, our understanding is that the treatment of MPM should not be merely 'copied' from that of other much better studied tumors. In the light of recent results, studies toward the metabolic characteristics of this tumor are being progressively addressed. These evidences are disclosing a rather unusual model of malignancy, very likely to be more sensitive to novel 'MPM cells- and microenvironment-tailored' therapy addressing these characteristics rather than the sole cancer proliferation.

Thalidomide versus active supportive care for maintenance in patients with malignant mesothelioma after first-line chemotherapy (NVALT 5): an open-label, multicentre, randomised phase 3 study.

BACKGROUND: Standard chemotherapy does not lead to long-term survival in patients with malignant pleural mesothelioma. Malignant pleural mesothelioma is strongly dependent on vasculature with high vessel counts and high concentrations of serum vascular growth factors. Thalidomide has shown antiangiogenic activity, and we hypothesised that its use in the maintenance setting could improve outcomes. METHODS: In this open-label, multicentre, randomised phase 3 study, eligible patients had proven malignant pleural or peritoneal mesothelioma and had received a minimum of four cycles of first-line treatment containing at least pemetrexed, with or without cisplatin or carboplatin, and had not progressed on this treatment. Patients were randomly assigned (in a 1:1 ratio, stratified by previous first-line chemotherapy, histological subtype, and recruiting hospital) to receive thalidomide 200 mg per day (including a 2 week run in of 100 mg per day) plus active supportive care or active supportive care alone until disease progression. Patients were required to be registered and to start treatment with thalidomide within 10 weeks after the end of the first-line chemotherapy. Thalidomide was given for a maximum of 1 year or until unacceptable toxicity. The primary endpoint was time to progression. The primary analyses were by intention to treat. The study is registered, ISRCTN13632914. FINDINGS: Between May 11, 2004, and Dec 23, 2009, we randomly assigned 222 patients, 111 in each group (one patient on active supportive care later withdrew consent and was excluded from analyses). At the time of this final analysis, median follow-up was 33.1 months (IQR 22.3-66.8), and physician-reported disease progression had occurred in 104 patients in the thalidomide group and 107 in the active supportive care group; 92 patients in the thalidomide group and 93 in the active supportive care group had died. Median time to progression in the thalidomide group was 3·6 months (95% CI 3.2-4.1) compared with 3.5 months (2.3-4.8) in the active supportive care group (hazard ratio 0.95, 95% CI 0.73-1.20, p=0.72). 43 (39%) grade 3 or 4 adverse events were reported in the thalidomide group and 31 (28%) in the active supportive care group; neurosensory events were reported by two (2%) patients on thalidomide and none on active supportive care, cardiac events by two (2%) patients on thalidomide and three (3%) on active supportive care, and thromboembolic events by three (3%) patients on thalidomide and none on active supportive care. INTERPRETATION: No benefit was noted in time to progression with the addition of thalidomide maintenance to first-line chemotherapy. Different treatment strategies are needed to improve outcomes in patients with malignant mesothelioma. FUNDING: Dutch Cancer Society (KWF), Eli Lilly, NSW Dust Disease Compensation Board, University of Sydney, and Cancer Australia.

Circulating endothelial cell (CEC) as a diagnostic and prognostic marker in malignant pleural mesothelioma (MPM).

BACKGROUND: The purpose of this study was to investigate the diagnostic and prognostic value of circulating endothelial cell (CEC), a potential surrogate of tumor angiogenesis, in malignant pleural mesothelioma (MPM). METHODS: We prospectively evaluated CEC count in 4.0 mL of peripheral blood sampled from patients with a suspicion of MPM. An automated system was used to capture CECs with an anti-CD146 antibody. RESULTS: Of 109 eligible patients, 30 were finally diagnosed with non-malignant diseases, and 79 were with MPM. CEC count was significantly higher in MPM patients than in NM patients (mean CEC count, 120.3 and 39.9, respectively; P = 0.001), and a receiver operating characteristic (ROC) curve analysis showed that CEC provided a significant diagnostic performance in discrimination between MPM and nonmalignant diseases with an area under curve (AUC-ROC) of 0.700 (95 % confidence interval [95 % CI], 0.595-0.806; P = 0.001). Among MPM patients, CEC count was positively correlated with intratumoral microvessel density (MVD), a measurement of tumor angiogenesis (Spearman correlation coefficiency [r] = 0.444; P = 0.001). Higher CEC count (>50) was significantly associated with a poor prognosis (median overall survival, 11.4 months [95 % CI, 7.6-15.2] for higher CEC count patients versus 20.1 months [95 % CI, 16.0-24.2] for lower CEC count patients; P = 0.028). A multivariate analysis showed that higher CEC count was a significant and independent factor to predict a poor prognosis (hazard ratio [HR], 2.24, [95 % CI, 1.24-4.43]; P = 0.009). CONCLUSIONS: CEC, as a surrogate of tumor angiogenesis, was a promising marker in diagnosis and prediction of prognosis in MPM.

Anti-angiogenic therapies for malignant pleural mesothelioma.

INTRODUCTION: Malignant pleural mesothelioma (MPM) is a disease with a dismal prognosis. Currently available treatments have modest results. Therefore, new agents and new treatment strategies are eagerly awaited by patients and clinicians. Preclinical and clinical studies have shown that angiogenesis plays a very important role in MPM. Therefore, a great hope has been placed in the use of anti-angiogenic agents in this disease. AREAS COVERED: Studies regarding anti-angiogenic treatments in MPM with bevacizumab, tyrosine-kinase inhibitors (TKIs) and other agents were critically analyzed, with an overview of ongoing trials and future perspectives, including research on biomarkers. EXPERT OPINION: The clinical use of angiogenesis inhibitors in MPM patients has resulted more challenging than anticipated. The intrinsic complexity of neo-angiogenesis, and its redundant regulatory mechanisms, suggests that multiple and different biomarkers are needed to predict efficacy of anti-angiogenic agents and to monitor their biological and therapeutic effects. The growing understanding of the molecular alterations and key pathways that underlie the resistance to VEGF inhibitors will allow to design studies of the combination of agents targeting these pathways with anti-VEGF therapies. Only a tight integration of preclinical and clinical studies will allow to achieve a real progress in MPM patients with this therapeutic strategy.

Photodynamic induced uptake of liposomal doxorubicin to rat lung tumors parallels tumor vascular density.

BACKGROUND: Visudyne®-mediated photodynamic therapy (PDT) at low drug/light conditions has shown to selectively enhance the uptake of liposomal doxorubicin in subpleural localized sarcoma tumors grown on rodent lungs without causing morphological alterations of the lung. The present experiments explore the impact of low-dose PDT on liposomal doxorubicin (Liporubicin™) uptake to different tumor types grown on rodent lungs. MATERIAL AND METHODS: Three groups of Fischer rats underwent subpleural generation of sarcoma, mesothelioma, or adenocarcinoma tumors on the left lung. At least five animals of each group (sarcoma, n = 5; mesothelioma, n = 7; adenocarcinoma, n = 5) underwent intraoperative low-dose (10 J/cm(2) at 35 mW/cm(2) ) PDT with 0.0625 mg/kg Visudyne® of the tumor and the lower lobe. This was followed by intravenous (IV) administration of 400 µg Liporubicin™. After a circulation time of 60 min, the tumor-bearing lung was processed for HPLC analyses. At least five animals per group underwent the same procedure but without PDT (sarcoma, n = 5; mesothelioma, n = 5; adenocarcinoma, n = 6). Five untreated animals per group underwent CD31 immunostaining of their tumors with histomorphometrical assessment of the tumor vascularization. RESULTS: Low-dose PDT significantly enhanced Liporubicin™ uptake to all tumor types (sarcoma, P = 0.0007; mesothelioma, P = 0.001; adenocarcinoma, P = 0.02) but not to normal lung tissue compared to IV drug administration alone. PDT led to a significantly increased ratio of tumor to lung tissue drug uptake for all three tumor types (P < 0.05). However, the tumor drug uptake varied between tumor types and paralleled tumor vascular density. The vascular density was significantly higher in sarcoma than in adenocarcinoma (P < 0.001) and mesothelioma (P < 0.001), whereas there was no significant difference between adenocarcinoma and mesothelioma. CONCLUSION: Low-dose Visudyne®-mediated PDT selectively enhances the uptake of systemically administered liposomal doxorubicin in tumors without affecting the drug uptake to normal lung. However, drug uptake varied significantly between tumor types and paralleled tumor vascular density.

[Anti-angiogenic factors in thoracic oncology: successes, failures and prospects]. / Traitements antiangiogéniques en oncologie thoracique: succès, échecs et perspectives.

Many growth factors involved in tumor angiogenesis are potential targets in thoracic oncology. This work is a review of the literature on the effectiveness of anti-angiogenic treatments in non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC) and malignant pleural mesothelioma (MM). Thirty-four articles and 15 abstracts were identified. Currently, bevacizumab is the only drug that has demonstrated an impact on overall survival in first line treatment for stage IV non-squamous NSCLC, but VEGFR-TKI such as cediranib, aflibercept, vandetanib, pazopanib have shown encouraging results in phase II or III clinical trials. In extensive-disease SCLC and inoperable MM, bevacizumab is the most studied molecule, but again, clinical trials are still ongoing. Current data on potential predictors for efficacy are disappointing, but some biomarkers or radiological techniques might be useful for guiding the use of anti-angiogenic therapies in the future. In conclusion, bevacizumab is the most studied anti-angiogenic agent in thoracic oncology. It is the only approved drug with an indication in first-line and maintenance treatment for stage IV non-squamous NSCLC. The indications for the use of VEGFR-TKI in clinical practice remain to be defined.

[A case of coexisting malignant mesothelioma and squamous cell carcinoma of the lung].

We experienced a case of malignant mesothelioma with squamous cell carcinoma of the lung concurrently. A 40-year-old man presented with dyspnea. A massive pleural effusion was found by X-ray in the right side of his chest. Transcutaneous pleural biopsy yielded a diagnosis of malignant mesothelioma(IMIG cT4N0M0, Stage IV ). At the same time, his chest CT revealed tumor in the right hilar lesion. Transbronchial lung biopsy yielded a diagnosis of squamous cell carcinoma of the lung (cT3N0M0, Stage III B). Our diagnosis was double cancer, malignant mesothelioma and lung cancer. Chemotherapy with carboplatin, gemcitabine and radiation therapy was performed, but the patient died from deterioration of his systemic condition. We encountered a rare case of double cancer. More attention must be paid in making a diagnosis of malignant mesothelioma and lung cancer.

Inhibition of Met/HGF receptor and angiogenesis by NK4 leads to suppression of tumor growth and migration in malignant pleural mesothelioma.

NK4 exhibits two distinct biological actions: antagonistic inhibition of hepatocyte growth factor (HGF) through binding to the Met/HGF receptor, and antiangiogenic action through binding to perlecan. Here, the anti-tumor effect of NK4 on malignant pleural mesothelioma was investigated. Of the 7 human malignant mesothelioma cell lines (ACC-Meso-1, ACC-Meso-4, EHMES-1, EHMES-10, H28, H2052 and JMN-1B), only EHMES-10 cells formed subcutaneous tumors when implanted into mice. For EHMES-10 cells, HGF facilitated invasion of the cells in collagen gel, whereas NK4 and neutralizing anti-HGF antibody suppressed the HGF-induced invasion. In addition, NK4 but not anti-HGF antibody suppressed proliferation of EHMES-10 cells in collagen, suggesting that the suppression by NK4 was independent of the HGF-Met pathway. In the subcutaneous tumor model, recombinant adenovirus-mediated intratumoral expression of NK4 inhibited tumor growth, while the invasive characteristic of tumor cells was not observed. Analysis of Met receptor tyrosine phosphorylation, proliferation, apoptosis and blood vessels in the tumor tissues indicated that the inhibitory effect of NK4 expression might be primarily caused by the inhibition of tumor angiogenesis. In all the 7 mesothelioma lines, HGF stimulated Met tyrosine phosphorylation, and this was associated with enhanced cell migration. HGF-dependent Met activation and migration were inhibited by NK4. Since malignant pleural mesothelioma represents an aggressive neoplasm characterized by extensive invasive growth, suppression of invasive growth has therapeutic value. Thus, the simultaneous inhibition of the HGF-Met pathway and angiogenesis by NK4 for treatment of malignant pleural mesothelioma is significant, particularly to attenuate migration and invasive growth.

Multimodality treatment of malignant pleural mesothelioma with or without immunotherapy: does it change anything?

The purpose of this study was to investigate immunological effector cells and angiogenesis in malignant pleural mesothelioma (MPM) patients, who underwent multimodality treatments. Clinical and pathological characteristics of 57 patients, with International Mesothelioma Interest Group stage II-III MPM, who underwent two different multimodality treatments (with and without immunotherapy) between 1999 and 2008 were analyzed. CD8+, CD4+ and Foxp3+ tumor-infiltrating lymphocytes, tryptase and chymase mast cells (MCs), CD34, number of microvessels and vascular endothelial growth factor were determined by immunohistochemistry. The histology was 51 epitheliomorf and 6 biphasic. The stage was III in 41 cases and II in 16 cases. With an average follow-up of 69 months (range 9-115) 14 patients are still alive and the overall median actuarial survival is 21.4 months. Tryptase MCs, CD8+ and Foxp3+ lymphocytes had significantly increased in the interleukin 2 (IL-2) treated group. Moreover, the number of microvessels was significantly lower in IL-2 treated patients. This study indicates that immunotherapy leads to an increase in cytotoxic CD8+ lymphocytes and tryptase MCs and to a decrease of the tumoral neoangiogenesis. Changes in MPM microenvironment induced by immunotherapy may play a major role in the local control of this disease and need further investigations.

Impact of tumor angiogenesis in peritoneal mesothelioma after radical cytoreduction and hyperthermic intraperitoneal chemotherapy.

Peritoneal mesothelioma is one of the peritoneal surface malignancies where long-term survival is a reality after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Tumor angiogenesis has been shown to be of prognostic significance on survival in mesothelioma. We investigated the impact of survival of patients with peritoneal mesothelioma following CRS and HIPEC to determine the impact of tumor angiogenesis on survival after this radical surgical treatment. Paraffin sections of 23 patients who were treated with CRS and HIPEC were retrieved for immunohistochemical analysis. The immunostaining was performed using monoclonal mouse anti-human antibodies (VEGF-C and CD31) on an autostainer (Autostainer Plus; Dako, Inc.). The intensity of the stains were quantified using the Image-Pro Plus (IPP) 4.5 (Media Cybernetics, Silver Spring, MD). VEGF expression and microvessel density (MVD) using CD31 staining were studied. The median survival was 94 months with a 3-year survival rate of 51%. There was no impact on patient's age, sex, peritoneal cancer index, tumor histopathology and survival outcomes between patients with low or high MVD and VEGF expression. After CRS and HIPEC, our results demonstrate that the prognostic significance of tumor angiogenesis is negated, highlighting the potential importance of other co-contributory mechanisms in mesotheliomagenesis and undergoing radial treatment.