Search

Since the outbreak of 2019 novel coronavirus disease (COVID-19) induced by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pandemic has become a global catastrophe. Patients with cancer especially lung cancer are more vulnerable and susceptible to get infected by the virus SARS-CoV-2. The overwhelming impact of COVID-19 on lung cancer community may result in rise of the incidence and mortality of lung cancer. It would become more obvious in future retrospective studies. Lung cancer patients are believed at higher risk of COVID-19 due to immunosuppression and should be protected by vaccination with priority. Better understanding of SARS-CoV-2 could help develop more effective vaccines to eradicate this disease in the near future.

Malignant pleural mesothelioma (MPM) is an intractable disease with an extremely poor prognosis. Our clinical protocol for MPM of subablative radiotherapy (RT) followed by radical surgery achieved better survival compared to other multimodal treatments, but local relapse and metastasis remain a problem. This subablative RT elicits an antitumoral immune response that is limited by the immunosuppressive microenvironment generated by regulatory T (Treg) cells. The antitumor effect of immunotherapy to simultaneously modulate the immune activation and the immune suppression after subablative RT has not been investigated in MPM. Herein, we demonstrated a rationale to combine interleukin-15 (IL-15) superagonist (IL-15SA) and glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) agonist (DTA-1) with subablative RT in mesothelioma. IL-15SA boosted the systemic expansion of specific antitumoral memory CD8+ T cells that were induced by RT in mice. Their effect, however, was limited by the up-regulation and activation of Treg cells in the radiated tumor microenvironment. Hence, selective depletion of intratumoral Treg cells through DTA-1 enhanced the benefit of subablative RT in combination with IL-15SA. The addition of surgical resection of the radiated tumor in combination with IL-15SA and DTA-1 maximized the benefit of RT and was accompanied by a reproducible abscopal response in a concomitant tumor model. These data support the development of clinical trials in MPM to test such treatment options for patients with locally advanced or metastatic tumors.

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm originating from the pleura. Non-epithelioid (biphasic and sarcomatoid) MPM are particularly resistant to therapy. We investigated the role of the GITR-GITRL pathway in mediating the resistance to therapy. We found that GITR and GITRL expressions were higher in the sarcomatoid cell line (CRL5946) than in non-sarcomatoid cell lines (CRL5915 and CRL5820), and that cisplatin and Cs-137 irradiation increased GITR and GITRL expressions on tumor cells. Transcriptome analysis demonstrated that the GITR-GITRL pathway was promoting tumor growth and inhibiting cell apoptosis. Furthermore, GITR+ and GITRL+ cells demonstrated increased spheroid formation in vitro and in vivo. Using patient derived xenografts (PDXs), we demonstrated that anti-GITR neutralizing antibodies attenuated tumor growth in sarcomatoid PDX mice. Tumor immunostaining demonstrated higher levels of GITR and GITRL expressions in non-epithelioid compared to epithelioid tumors. Among 73 patients uniformly treated with accelerated radiation therapy followed by surgery, the intensity of GITR expression after radiation negatively correlated with survival in non-epithelioid MPM patients. In conclusion, the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma, associated with tumor stemness and resistance to therapy. Blocking the GITR-GITRL pathway could be a new therapeutic target for non-epithelioid mesothelioma., Chan et al find that the GITR-GITRL pathway is an important mechanism of autocrine proliferation in sarcomatoid mesothelioma that could explain their resistance to therapy. Blocking the GITR-GITRL pathway could therefore be a new therapeutic target for non-epithelioid mesothelioma.

// Mathieu Francois Derouet 1 , Eugenia Dakpo 1 , Licun Wu 1 , Guan Zehong 1 , James Conner 4 , Shaf Keshavjee 1, 2 , Marc de Perrot 1, 2 , Thomas Waddell 1, 2 , Elena Elimova 3 , Jonathan Yeung 1, 2 and Gail Elizabeth Darling 1, 2 1 Latner Thoracic Surgery Research Laboratories, Princess Margaret Cancer Research Tower, University Health Network, Toronto, Ontario, Canada 2 Department of Surgery, Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada 3 Department of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada 4 Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada Correspondence to: Mathieu Francois Derouet, email: mderouet@uhnresearch.ca Gail Elizabeth Darling, email: gdarling@uhn.ca Keywords: esophageal adenocarcinoma; miR-145; c-Myc; integrins; metastasis Abbreviations: CLL: Chronic Lymphocytic Leukemia; EAC: Esophageal Adenocarcinoma; FCS: Foetal Calf Serum; HRP: Horseradish Peroxidase; PVDF: Polyvinylidene Received: June 07, 2017 Accepted: February 21, 2018 Epub: March 08, 2018 Published: March 16, 2018 ABSTRACT Adenocarcinoma of the esophagus is increasing in frequency and is the 6th most common cause of cancer death in North America. In adenocarcinoma cell lines, we have previously demonstrated that expression of miR-145, leads to enhanced invasion, resistance to anoikis and better attachment to fibronectin in esophageal adenocarcinoma. In contrast, expression of miR-145 acts as a tumor suppressor in squamous cell carcinoma. The molecular mechanisms responsible for the oncogenic effects of miR-145 were investigated. In this report, we demonstrate that we can partially recreate the miR-145 effects in EAC by knock down of the expression of c-Myc, which is one of the targets of miR-145. Knocking down of c-Myc expression resulted in upregulation of integrin subunits α5 and β3. Finally, we demonstrated that integrin α5 expression correlates to fibronectin attachment potential whereas integrin β3 expression correlates with resistance to anoikis and invasion potential. Finally, we demonstrate that expression of miR-145 in esophageal adenocarcinoma cell line (SK-GT-4) enhances tumor growth and metastasis in a NOD/SCID xenograft model. Overall, the oncogenic potential of miR-145 in EAC appears to be mediated by downregulation of c-Myc leading to the expression of integrins subunits α5 and β3.

Background: Malignant pleural mesothelioma (MESO) has a poor prognosis despite aggressive treatment with surgery, radiation and chemotherapy, and novel therapeutic approaches are needed. IRF3 is a downstream molecule of the cGAS/STING signaling pathway, but its roles have not been investigated in MESO. Methods: Various murine mesothelioma cell lines were inoculated into wild type (WT) and IRF3 knockout (IRF3KO) mice to compare tumor growth. AE17-bearing mice were treated with local radiotherapy (LRT) to evaluate the effect on tumor growth, and immune cell infiltration was analyzed by flow cytometry 20 days after tumor inoculation. TCGA data were used to examine the relationship between mRNA expression of IRF3 and genes of the cGAS/STING signaling cascade on prognosis in MESO. Correlations between gene expression of IRF3, cGAS/STING signaling pathway, and immune checkpoints were analyzed in TCGA MESO and our scRNA-Seq data from MESO patients. Results: In mouse mesothelioma models, AK7, RN5 and ZiP3 were completely rejected in IRF3KO mice 20 days after the tumor challenge. AE17tumor volume was slightly larger than WT mice around day 10 before shrinking and becoming significantly smaller than WT mice on day 20. LRT accelerated tumor shrinkage of AE17 tumors in IRF3KO mice. Compared with WT mice, the number of macrophages infiltrating the tumor of IRF3KO mice was significantly reduced, and CD4+ T cells and CD8+IFNγ+ T cells were significantly increased. TCGA data showed that IRF3 expression was an unfavorable prognostic factor in MESO patients. IRF3 expression, the cGAS/STING signaling pathway, and immune checkpoints were positively correlated. Conclusion: IRF3 could play a critical role in the tumor immune microenvironment of MESO.

Summary Malignant pleural mesothelioma is an aggressive disease that continues to be associated with poor outcomes. Although, traditionally this disease is considered to be resistant to radiotherapy, more recent evidence suggests that radiotherapy can produce positive outcomes. Over the past 15 years, the development of new, highly conformal radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), has enabled investigators to optimise the delivery of high-dose radiotherapy to the whole of the hemithorax. Prospective single-arm trials have shown that the median survival of patients who have completed high-dose hemithoracic radiotherapy after extrapleural pneumonectomy could reach 23·9–39·4 months independent of the chemotherapeutic response, suggesting that IMRT could potentially have an intrinsic benefit to this subset of patients. These observations have led to a change in practice, with the introduction of adjuvant pleural IMRT after pleurectomy-decortication and the development of induction-accelerated hemithoracic IMRT followed by extrapleural pneumonectomy. This Review focuses on recent observations on the role of radiotherapy in the treatment of malignant pleural mesothelioma, with particular emphasis on the results of clinical trials that evaluate the role of high-dose hemithoracic radiotherapy.

This study was undertaken to characterize the molecular and pathological mechanisms of pulmonary vascular remodeling in a patient who developed chronic lung allograft dysfunction and recurrent pulmonary hypertension (PH) 22 years after undergoing a right single lung transplantation for pulmonary arterial hypertension (PAH). Histopathologic examination of the explanted lungs at the time of retransplantation showed characteristics of diffuse vascular remodeling combined with features of acute and chronic thromboemboli and evidence of bronchiolitis obliterans in the right lung allograft. In contrast, the native left lung demonstrated pulmonary arterial changes in keeping with PAH associated with disseminated pulmonary ossification. Real-time polymerase chain reaction and Western blot—performed on the first lung allograft, the native lung, and the new donor lung—demonstrated increased expression of apoptotic-related gene and protein levels in the lung allograft compared with the native PAH lung and the donor lung. Localization of cell apoptosis determined by triple immunostaining for caspase 3, CD31, and smooth muscle actin was positive in the pulmonary endothelial cells but not the smooth muscle cells of the lung allograft, while no positive staining was detected for cell death in the native PAH lung. The presence of PH in the lung allograft 22 years after transplantation was associated with upregulation of apoptotic markers and evidence of apoptotic endothelial cell death compared with the native lung and donor lung.

Cytotoxic CD8+ tumor infiltrating lymphocytes (TILs) can contribute to the benefit of hypofractionated radiation, but programmed cell death pathways (programmed cell death 1 and programmed cell death ligand 1 [PD-1/PD-L1]) may provide a mechanism of tumor immune escape. We therefore reviewed the influence of PD-1/PD-L1 and CD8+ TILs on survival after accelerated hypofractionated hemithoracic radiation followed by extrapleural pneumonectomy for malignant pleural mesothelioma (MPM).Sixty-nine consecutive patients undergoing the protocol of Surgery for Mesothelioma after Radiation Therapy (SMART) between November 2008 and February 2016 were analyzed for the presence of PD-L1 on tumor cells, PD-1 on inflammatory cells, and CD8+ TILs. Comparison was made with a cohort of patients undergoing extrapleural pneumonectomy after induction chemotherapy (n = 14) and no induction (n = 2) between March 2005 and October 2008. PD-L1 expression on tumor cells ≥1% was considered positive. CD8+ TILs and PD-1 expression were scored as a percentage of positive cells.PD-L1 was negative in 75% of MPM after completion of SMART. CD8+ TILs ranged between 0.24% and 8.47% (median 2%). CD8+ TILs ≥2% was associated with significantly better survival in epithelioid MPM (median survival 3.7 years vs 2.3 years in CD8+ TILs2%; P = .02). PD-L1 positivity was associated with worse survival in biphasic MPM (median survival, 0.4 years vs 1.5 years in biphasic PD-L1 negative tumors; P = .07) after SMART. Multivariate analysis demonstrated that epithelioid MPM, nodal disease, and CD8+ TILs were independent predictors of survival after SMART.The influence of tumor microenvironment on survival differs between epithelioid and nonepithelioid MPM. CD8+ TILs is an independent factor associated with better survival in epithelioid MPM treated with SMART.

Purpose Chronic thromboembolic pulmonary hypertension (CTEPH), is a progressive condition characterized by persistent elevation in pulmonary artery pressure due to thromboembolic occlusion of the pulmonary arteries. Little is known about the cells that make up the cast of pulmonary endarterectomy (PEA) and its immune microenvironment. Here we report a map of the cellular landscape of the human PEA specimen using single-cell RNA sequencing. Methods Five human PEA specimen from the proximal pulmonary arteries were collected from CTEPH patients who underwent PEA surgery. The protocol was approved (University Health Network, REB# 18-5892). 10x sample processing and cDNA library preparation was prepared using the 10x Genomics Single Cell Reagent Kit. Molecular analysis, Western blot, and immunohistochemistry were also performed. Results The transcriptional profiles of 12598 cells obtained by fractionating fresh tissues from five CTEPH patients after PEA are presented in Figure 1. Using gene expression patterns and immunohistochemical examinations, we identified 18 discrete cell populations with distinct endothelial cell, smooth muscle cell, monocyte/macrophage, T cell, B cell, and NK-like cell characteristics. Transcription of endothelin-1 was observed in endothelial cells from every patient. The expression of endothelin-1 was confirmed by Western blot and immunohistochemistry in the PEA specimen from an additional 14 CTEPH patients undergoing surgery. Conclusion Single cell RNA sequencing demonstrates a large population of inflammatory cells combined with endothelial cells and smooth muscle cell in the cast of PEA. Endothelin-1 expression by endothelial cells may contribute to the development of PH in patients with CTEPH.

Here we summarize the most recent update of mesothelioma research in basic science presented at the 14th iMig2018 international conference. The symposium of basic science track mainly focused on the drivers of mesothelioma initiation and progression, molecular pathogenesis, and perspectives on potential therapeutic approaches. This review covers several promising fields including strategies efficiently inhibiting YAP/TAZ functions or their critical downstream targets, heparanase inhibitors, RAN depletion, and MIF/CD74 inhibitors that may be developed as novel therapeutic approaches. In addition, targeting mesothelioma stem cells by depleting M2-polarized macrophages in tumor microenvironment or blocking Tnfsf18 (GITRL)-GITR signalling might be translated into therapeutic modalities in mesothelioma treatment.

// Licun Wu 1 , Matthew Onn Wu 1 , Luis De la Maza 1 , Zhihong Yun 1 , Julie Yu 1 , Yidan Zhao 1 , John Cho 2 and Marc de Perrot 1 1 Latner Thoracic Surgery Research Laboratories and Division of Thoracic Surgery, Toronto General Hospital, University Health Network, University of Toronto, Toronto, ON, Canada 2 Radiation Oncology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, ON, Canada Correspondence to: Marc de Perrot, email: // Keywords : mesothelioma, local radiotherapy, abscopal effect, immune checkpoint Received : November 24, 2014 Accepted : February 03, 2015 Published : March 08, 2015 Abstract We previously demonstrated that blockade of immune suppressive CTLA-4 resulted in tumor growth delay when combined with chemotherapy in murine mesothelioma. Tumor-infiltrating T cells (TIT) after local radiotherapy (LRT) play critical roles in abscopal effect against cancer. We attempt to improve the local and abscopal effect by modulating T cell immunity with systemic blockade of CTLA-4 signal.The growth of primary tumors was significantly inhibited by LRT while CTLA-4 antibody enhanced the antitumor effect. Growth delay of the second tumors was achieved when the primary tumor was radiated. LRT resulted in more T cell infiltration into both tumors, including Treg and cytotoxic T cells. Interestingly, the proportion of Treg over effector T cells in both tumors was reversed after CTLA-4 blockade, while CD8 T cells were further activated. The expression of the immune-related genes was upregulated and cytokine production was significantly increased. LRT resulted in an increase of TIT, while CTLA-4 blockade led to significant reduction of Tregs and increase of cytotoxic T cells in both tumors. The abscopal effect is enhanced by targeting the immune checkpoints through modulation of T cell immune response in murine mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive neoplasm with poor outcome. Novel radical radiation techniques using intensity modulated radiation therapy (IMRT) have become an important component of therapy in mesothelioma. Immunotherapy also provides new therapeutic options. However, how best to integrate immunotherapy with standard therapy such as radiation, chemotherapy and surgery remains unknown. A change of paradigm from adjuvant normofractionation to induction accelerated hypofractionated hemithoracic radiation could provide a platform to combine immunotherapy due to the potential benefit of short course high dose radiation on the immune system. Immunotherapy can also be combined with chemotherapy. Although chemotherapy is generally considered immunosuppressive, some chemotherapeutic agents do induce cell death that can be immunogenic and stimulate a specific immune response against the tumor. Immunotherapy could also be used in between cycles of chemotherapy to limit tumor cell repopulation and optimize the results of both treatments. The integration of immunotherapy into a multimodality approach is opening new avenue of treatment for mesothelioma.

To facilitate online maintenance for High Pressure Safety Injection (HPSI) system in nuclear power plant, the optimization measure for Allowed Outage Time (AOT) is proposed in this paper, and risk-Informed decision-making approach is used to demonstrate its feasibility. According to the analysis results, the extension of AOT meets the requirements of relative guides and deterministic analysis, and the impact on risk of plant is acceptable. Based on the extension of AOT, it is feasible to carry out online maintenance for safety system and corresponding support systems, which can effectively reduce workload during shutdown.

Although multiple, complex molecular studies have been done for understanding the development and progression of pulmonary hypertension (PAH), little is known about the metabolic heterogeneity of PAH. Using a combination of high-throughput liquid-and-gas-chromatography-based mass spectrometry, we found bile acid metabolites, which are normally product derivatives of the liver and gallbladder, were highly increased in the PAH lung. Microarray showed that the gene encoding cytochrome P450 7B1 (CYP7B1), an isozyme for bile acid synthesis, was highly expressed in the PAH lung compared with the control. CYP7B1 protein was found to be primarily localized on pulmonary vascular endothelial cells suggesting de novo bile acid synthesis may be involved in the development of PAH. Here, by profiling the metabolomic heterogeneity of the PAH lung, we reveal a newly discovered pathogenesis mechanism of PAH. Electronic supplementary material The online version of this article (doi:10.1007/s11306-014-0653-y) contains supplementary material, which is available to authorized users.

The supercritical water-cooled reactor (SCWR) is one of the most promising Generation IV reactors. In order to make the fuel qualification test for SCWR, a research plan is proposed to test a small scale fuel assembly in a supercritical water loop. To ensure the structure safety of fuel assembly in the loop, a flow-induced vibration experiment was carried out to investigate the vibration behavior of fuel rods, especially the vibration caused by leakage flow. From the experiment result, it can be found that: the vibration of rods is mainly caused by turbulence when flow rate is low. However, the effects of leakage flow become obvious as flow rate increases, which could changes the distribution of vibrational energy in spectrum, increasing the vibrational energy in high-frequency band. That is detrimental to the structure safety of fuel rods. Therefore, it is more reasonable to improve the design by using the spacers with blind hole, which can eliminate the leakage flow, to assemble the fuel rods in supercritical water loop. On the other hand, the experimental result could provide a benchmark for the theoretical studies to validate the applicability of boundary condition set for the leakage-flow-induced vibration.

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor of the pleura closely related to asbestos exposure. Rare as it is, the incidence of MPM is predicted to increase mainly as a result of a lengthy latency period from the initial asbestos exposure, making it a public health concern for the next decades. Moreover, the patients with MPM have an extremely poor prognosis due to its high resistance to conventional oncologic treatments and delayed diagnosis. Although the result of current therapeutic modalities based on patient features and clinical stages is very frustrating, great advances have been shown in the knowledge of molecular biology of MPM in recent years. This is accompanied by dozens of putative prognostic biomarkers that are actively involved in tumor biological activities. These prognostic candidates can offer us a new insight into the biological characteristics of MPM, contributing to development of individualized therapeutic strategies directed against oncogenesis and tumor progression. Thus, personalized approaches based on the molecular biology of the patient’s tissue or body fluid will potentially improve the present disappointing outcome, bringing new hope for patients with MPM. This article reviews the principal and several novel biomarkers that can have an influence on prognosis, in the hope that they can provide us with a more profound understanding of the biology of this lethal disease.

Selective inhibition of repopulation of clonogenic tumor cells between courses of chemotherapy has potential to improve the effectiveness of treatment. Here we study arzoxifene, a short-acting selective estrogen receptor modulator, for its potential to inhibit repopulation in estrogen-dependent human breast cancer MCF-7 xenografts between courses of chemotherapy. Proliferation of tumor cells was evaluated by cyclin D1 expression and uptake of 5-bromo-2′-deoxyuridine. Arzoxifene decreased cell proliferation in xenografts. To model adjuvant treatment of human breast cancer, MCF-7 cells were injected s.c. into nude mice and four groups of mice received the following treatments beginning after implantation: (a) control (vehicle solution); (b) arzoxifene alone, 5 days per week by oral gavage for 3 weeks; (c) 5-fluorouracil (5-FU) or paclitaxel i.p. weekly, for 3 doses; and (d) arzoxifene following each cycle of chemotherapy. The incidence of tumors with volume ≥50 mm3 was determined as a function of time. MCF-7 xenografts developed in 100% of control mice by 4 weeks after implantation. Paclitaxel or 5-FU alone had minor effects to delay the appearance of xenografts whereas arzoxifene alone caused longer delay. Combined treatment with arzoxifene given between cycles of 5-FU or paclitaxel had substantial effects, with ∼50% tumor incidence by 5 weeks. Our results indicate that arzoxifene can inhibit repopulation of hormone-responsive MCF-7 breast cancer xenografts when given between courses of chemotherapy. The scheduling of short-acting hormonal agents between courses of adjuvant chemotherapy for human breast cancer has potential to improve the outcome of treatment.

Although much work has been performed on the liquid sloshing inside simple structures like rectangular and cylindrical vessels, this paper deals with the analysis of the liquid sloshing in a more complex structures, the in-containment refueling water storage tank (IRWST). The IRWST is an important component of AP1000 passive core cooling system to ensure the safe operation of the AP1000 nuclear power plant. In postulated non-LOCA events, the water in the IRWST absorbs the residual heat then transfers the heat into the containment atmosphere. However, in the case of earthquake, the sloshing fluid may influence the safety of the appropriate semi-cylindrical IRWST. In this paper, the liquid transient response in the IRWST was formulated based on finite element modal analysis when the three resonance sine wave was applied as excitation. The result shows that the maximum wave excited by excitation from different directions always emerges from the corner or the edge of tank. Another finding is that water will not overflow at the normal operational water level when exited by the selected excitations in any directions. The safety of the IRWST’s roof is achieved which guarantees that the water vapor and radioactive gases within the tank during normal operation will not release to atmosphere in the containment. The influence of the excitation direction and the water depth are also analyzed.

CD4+CD25+ regulatory T cells (Tregs) can promote the growth of some tumors, but it is unknown whether this is true for all tumors, including malignant pleural mesothelioma. We have previously shown that the existence of Tregs was associated with poor survival in patients with malignant pleural mesothelioma. In this study, using an intrathoracic murine model of malignant mesothelioma (MM), we provide evidence suggesting that Treg blockade could enhance survival when combined with pemetrexed in established tumor. AC29 murine MM cells were injected into the right pleural cavity of CBA mice for tumor development. Four days after the tumor injection, tumor-bearing mice were then treated with pemetrexed alone, Treg blockade alone, or a combination of pemetrexed and Treg blockade. We observed a synergistic antitumor effect of Treg blockade combined with pemetrexed resulting in prolonged survival. The combination of Treg blockade and pemetrexed was associated with decreased tumor-infiltrating Tregs, increased IL-2 production, dendritic cell maturation, and increased CD3+CD8+IFN-γ+ tumor-infiltrating T cells when compared with mice treated with pemetrexed alone or Treg blockade alone. The survival benefit was abrogated if anti-CD8 mAb was administered simultaneously. Likewise, the survival benefit resulting from the combined Treg blockade with pemetrexed was not observed when immunodeficient mice were used. Therefore, this study suggests that Treg blockade combined with pemetrexed can suppress mesothelioma growth in established tumor in vivo through an immune-mediated process. This study also validates a new intrathoracic tumor model of pleural effusion to explore the role of antitumor immunity in murine MM.

Purpose: Optimal scheduling of cycle-active chemotherapy with (initially cytostatic) molecular-targeted agents is important to maximize clinical benefit. Concurrent scheduling might allow up-regulation of cell death pathways at the time of chemotherapy, whereas sequential treatments might maximize inhibition of repopulation and avoid putting tumor cells out of cycle when administering cycle-active chemotherapy. We compared the effects of concurrent and sequential administration of chemotherapy and the mammalian target of rapamycin (mTOR) inhibitor temsirolimus (CCI-779) on tumor cells and xenografts. Experimental Design: Human prostate cancer PC-3 and LnCaP, and human breast cancer MDA-468 cells and xenografts were treated with chemotherapy (docetaxel and 5-fluorouracil, respectively) and temsirolimus, using concurrent and sequential treatment schedules. Cell killing and repopulation were evaluated by clonogenic assays. Cell cycle analysis was done using flow cytometry. Effects on xenografts were assessed by tumor growth delay. Results: The proliferation of all cell lines was inhibited by temsirolimus in a dose-dependent manner; PTEN negative PC-3 and mutant LnCaP cells were more sensitive than PTEN-negative MDA-468 cells. Temsirolimus inhibited cell cycle progression from G1 to S phase in all cell lines. Combined treatment had greater effects than temsirolimus or chemotherapy alone: for PC-3 and LnCaP xenografts, concurrent treatment seemed superior to sequential scheduling, whereas MDA-468 cells and xenograft tumors did not show schedule dependence. Conclusions: Combined treatment with temsirolimus and chemotherapy had a greater therapeutic effect than monotherapy; concurrent scheduling was more effective for PC-3 and LnCaP cells and xenografts that were sensitive to temsirolimus. (Clin Cancer Res 2009;15(17):5389–95)

Purpose Pulmonary arterial hypertension (PH) is an unremitting disease defined by progressive increase in pulmonary vascular resistance and vascular remodeling. Currently, little is known about treatments that affect vascular endothelial cell related pathogenic feature of PH. We propose to use photodynamic therapy (PDT) to treat PH, which use vascular specific light sensitive drug (a photosensitizer) and light in the presence of oxygen to irreversibly damage cells. We hypothesize that PDT can reverse vascular remodeling in PH through anti-endothelial proliferative mechanisms. Aim of this study therefore is to evaluate the therapeutic effects of PDT using animal PH model. Methods and Materials To induce PH, Sprague Dawley rats were injected with 60mg/kg monocrotaline (MCT). At day 7, PDT (630nm, 50 J/cm 2 ) using the photosensitizer, aminolevulinic acid (ALA) was administered. Hemodynamic measurements were taken on day 21 and lung and heart samples were dissected for molecular protein analysis. Results Rats treated with PDT using ALA had a significant reduction in right ventricular systolic pressure (RVSP), implying lower pulmonary arterial pressure, and a decreased ratio of RV/LV+S (right ventricle/left ventricle + septum), signifying reduced RV hypertrophy, compared with MCT-PH rats that received solely laser treatment. We observed a significant increase in P21Cip expression and decreased CKD1 and PCNA expression in the rat receiving PDT treatment. Hematoxylin and immunostaining showed PDT partially reverse MCT induced vascular remodeling in the lung treated versus untreated rats. Conclusions The clinical relevance of the findings in animal models will be assessed in human PAH lung tissue after lung transplantation. With these studies, we hope to provide new approaches for the treatment of this devastating disease.

Introduction: NKT cells can provide adjuvant activity against cancer by producing large amounts of IFN-gamma which activate other immune cells, and orchestrate protective anti-tumor immunity. Recently, induction of the NKT cell-dependent anti-tumor immune response using its ligand alpha-galactosylceramide has been attempted in several tumor types. However, the role of NKT cells in the tumor microenvironment has not yet been fully addressed. Our aim is to elucidate the role of NKT cells in the thoracic cavity by using a murine malignant mesothelioma model. Methods: Half a million of AB12 murine malignant mesothelioma cells were injected into the right pleural cavity of female Balb/c mice for tumor development. The control mice were injected with the same amount of PBS. In this model, thoracic cavity was filled with tumors and pleural effusion by day 14. On days 0 (before tumor cell injection), 3, 6, 10 and 14 after tumor cell injection, mice were sacrificed and the pleural effusion and tumors were collected. Lymphocytes were isolated by performing a Ficoll gradient centrifugation. Cell phenotype was identified by cell surface marker staining and cytokine expression was analyzed by intracellular cytokine staining using flow cytometry. Cytokine concentrations in the pleural effusion were measured by ELISA. Resluts: The absolute number of CD3 positive cells in the pleural cavity did not increase between day 0 (4.7±0.9 x105), day 3 (5.5±0.7 x105) and day 6 (7.1x±1.6 x105) but did start to increase from day 10 (1.2±0.2 x106) after tumor cell injection. In the control mice, the absolute number of CD3 positive cells was not different throughout the experiment. Although the absolute number of CD8 positive cells and CD4 positive cells were not different between day 0 (CD8: 1.5±0.2 x105, CD4: 2.8±0.2 x105, respectively), day 3 (CD8: 1.8±0.2 x105, CD4: 2.6±0.2 x105, respectively) and day 6 (CD8: 1.9±0.4 x105, CD4: 4.3±0.2 x105, respectively) after tumor cell injection, the absolute number of NKT cells (CD3 and DX5 double positive cells) increased dramatically at relatively earlier phase from 1.6±0.1 x104 on day 0, to 6.4±0.3 x104 on day 3 and 12.1±1.0 x104 on day 14. Intracellular IFN-gamma staining of NKT and CD8 T cells showed that the ratio of IFN-gamma positive NKT to whole NKT cells started increasing from day 3 (day0: 7.0±1.3%, day3: 31±3%, respectively) and peaked on day 6 (59±11%) whereas the ratio of IFN-gamma positive to whole CD8 T cells started increasing from day 6 (day0: 12.1±3.5%, day6: 36±6.5%) and peaked on day 10 (39±3.4%). Conclusion: These results indicate that the NKT cells are recruited to the pleural cavity at a relatively early phase of tumor formation and could potentially affect the subsequent CD8 T cell response by the production of IFN-gamma. Further experiments are on going to see the role of NKT cells and to test the impact of chemotherapy on these cells in this model. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 777. doi:10.1158/1538-7445.AM2011-777