[The Achievements for"7-University Joint Project of Training Plan for Oncology Professionals].

In recent years, cancer medical care in Japan is required to respond to diversifying new needs and issues. Among these, the practical application of genomic medicine, measures against rare cancer and childhood cancer, and the response to specific problems that occur in cancer patients with different life stages are urgent issues to be resolved. The aim of this plan is to train multidisciplinary oncology professionals who provide personalized medicine that meets various new needs in cancer medicine through mutual cooperation between graduate school of medicine, nursing, pharmaceutics, and genetic counseling of 7 national, public and private universities and 9 faculties located in Osaka and Hyogo. To achieve the goal, we set up 3 task forces(TFs)to address these issues. In the TF1"genome science", we implemented genomic medicine and promote inter-university and industry-academia-government joint research. TF2"educational innovation"promoted the development of innovative educational programs to realize personalized medicine. In the TF3"multi-partnership alliance", we strengthened cooperation and support systems with regional medical institutions, local governments/public institutions, patients' associations including cancer survivors, and non-profit organizations, and focused on the promotion of cancer palliative care. By practically collaborating with each TF, we achieved training for multidisciplinary oncology professionals who could practice patient-centered personalized medicine.

Clinical Application of the FoundationOne CDx Assay to Therapeutic Decision-Making for Patients with Advanced Solid Tumors.

BACKGROUND: Implementation of personalized medicine requires the accessibility of tumor molecular profiling in order to allow prioritization of appropriate targeted therapies for individual patients. Our aim was to study the role of comprehensive genomic profiling assays that may inform treatment recommendations for patients with solid tumors. MATERIALS AND METHODS: We performed a prospective study to evaluate the feasibility of application of the FoundationOne CDx panel-which detects substitutions, insertions and deletions, and copy number alterations in 324 genes, select gene rearrangements, and genomic signatures including microsatellite instability and tumor mutation burden (TMB)-to patients with advanced or recurrent solid tumors before its approval in Japan. RESULTS: A total of 181 samples were processed for genomic testing between September 2018 and June 2019, with data being successfully obtained for 175 of these samples, yielding a success rate of 96.7%. The median turnaround time was 41 days (range, 21-126 days). The most common known or likely pathogenic variants were TP53 mutations (n = 113), PIK3CA mutations (n = 33), APC mutations (n = 32), and KRAS mutations (n = 29). Among the 153 patients assessed for TMB, the median TMB was 4 mutations/Mb, and tumors with a high TMB (≥10 mutations/Mb) were more prevalent for lung cancer (11/32) than for other solid tumor types (9/121, Fisher's exact test p < .01). No clear trend toward increased efficacy for immune checkpoint inhibitor (ICI) monotherapy or ICI combination chemotherapy in patients with a high programmed cell death-ligand 1 tumor proportion score or a high TMB was apparent. Among the 174 patients found to harbor known or likely pathogenic actionable alterations, 24 individuals (14%) received matched targeted therapy. CONCLUSION: The FoundationOne CDx assay was performed with formalin-fixed, paraffin-embedded tumor specimens with a success rate of >95%. Such testing may inform the matching of patients with cancer with investigational or approved targeted drugs. IMPLICATIONS FOR PRACTICE: This prospective cohort study was initiated to investigate the feasibility and utility of clinical application of FoundationOne CDx. A total of 181 samples were processed for genomic testing between September 2018 and June 2019, with data being successfully obtained for 175 of these samples, yielding a success rate of 96.7%, and 24 individuals (14%) received matched targeted therapy.

Trimodality strategy for treating malignant pleural mesothelioma: results of a feasibility study of induction pemetrexed plus cisplatin followed by extrapleural pneumonectomy and postoperative hemithoracic radiation (Japan Mesothelioma Interest Group 0601 Trial).

PURPOSE: We conducted a prospective multi-institutional study to determine the feasibility of trimodality therapy (TMT) comprising induction chemotherapy followed by extrapleural pneumonectomy (EPP) and radiation therapy in Japanese patients with malignant pleural mesothelioma (MPM). METHODS: Major eligibility criteria were histologically confirmed diagnosis of MPM, including clinical subtypes T0-3, N0-2, M0 disease; no prior treatment for the disease; age 20-75 years; Eastern Cooperative Oncology Group performance status 0 or 1; predicted postoperative forced expiratory volume >1000 ml in 1 s; written informed consent. Treatment methods comprised induction chemotherapy using pemetrexed (500 mg/m(2)) plus cisplatin (60 mg/m(2)) for three cycles, followed by EPP and postoperative hemithoracic radiation therapy (54 Gy). Primary endpoints were macroscopic complete resection (MCR) rate for EPP and treatment-related mortality for TMT. RESULTS: Forty-two eligible patients were enrolled: median age 64.5 (range 43-74) years; M:F = 39:3, clinical stage I:II:III = 14:13:15; histological type epithelioid were sarcomatoid; biphasic; others = 28:1:9:4. Of 42 patients, 30 completed EPP with MCR and 17 completed TMT. The trial met the primary endpoints, with an MCR rate of 71 % (30/42) and treatment-related mortality of 9.5 % (4/42). Overall median survival time and 2-year survival rate for 42 registered patients were 19.9 months and 42.9 %, respectively. Two-year relapse-free survival rate of 30 patients who completed EPP with MCR was 37.0 %. CONCLUSION: This phase II study met the predefined primary endpoints, but its risk/benefit ratio was not satisfactory.

Vorinostat in patients with advanced malignant pleural mesothelioma who have progressed on previous chemotherapy (VANTAGE-014): a phase 3, double-blind, randomised, placebo-controlled trial.

BACKGROUND: Vorinostat is a histone deacetylase inhibitor that changes gene expression and protein activity. On the basis of the clinical benefit reported in patients with malignant pleural mesothelioma treated in a phase 1 study of vorinostat, we designed this phase 3 trial to investigate whether vorinostat given as a second-line or third-line therapy improved patients' overall survival. METHODS: This double-blind, randomised, placebo-controlled trial was done in 90 international centres. Patients with measurable advanced malignant pleural mesothelioma and disease progression after one or two previous systemic regimens were eligible. After stratification for Karnofsky performance status, histology, and number of previous chemotherapy regimens, patients were randomly assigned (1:1) by use of an interactive voice response system with a block size of four to either treatment with vorinostat or placebo. Patients received oral vorinostat 300 mg (or matching placebo) twice daily on days 1, 2, 3, 8, 9, 10, 15, 16, and 17 of a 21-day cycle. The primary endpoints were overall survival and safety and tolerability of vorinostat. The primary efficacy comparison was done in the intention-to-treat population, and safety and tolerability was assessed in the treated population. This trial is registered with ClinicalTrials.gov, number NCT00128102. FINDINGS: From July 12, 2005, to Feb 14, 2011, 661 patients were enrolled and randomly assigned to receive either vorinostat (n=329) or placebo (n=332) and included in the intention-to-treat analysis. Median overall survival for vorinostat was 30·7 weeks (95% CI 26·7-36·1) versus 27·1 weeks (23·1-31·9) for placebo (hazard ratio 0·98, 95% CI 0·83-1·17, p=0·86). The most common grade 3 or worse adverse events for patients treated with vorinostat were fatigue or malaise (51 [16%] patients in the vorinostat group vs 25 [8%] in the placebo group]) and dyspnoea (35 [11%] vs 45 [14%]). INTERPRETATION: In this randomised trial, vorinostat given as a second-line or third-line therapy did not improve overall survival and cannot be recommended as a therapy for patients with advanced malignant pleural mesothelioma. FUNDING: Merck & Co.

Biallelic germline and somatic mutations in malignant mesothelioma: multiple mutations in transcription regulators including mSWI/SNF genes.

We detected low levels of acetylation for histone H3 tail lysines in malignant mesothelioma (MM) cell lines resistant to histone deacetylase inhibitors. To identify the possible genetic causes related to the low histone acetylation levels, whole-exome sequencing was conducted with MM cell lines established from eight patients. A mono-allelic variant of BRD1 was common to two MM cell lines with very low acetylation levels. We identified 318 homozygous protein-damaging variants/mutations (18-78 variants/mutations per patient); annotation analysis showed enrichment of the molecules associated with mammalian SWI/SNF (mSWI/SNF) chromatin remodeling complexes and co-activators that facilitate initiation of transcription. In seven of the patients, we detected a combination of variants in histone modifiers or transcription factors/co-factors, in addition to variants in mSWI/SNF. Direct sequencing showed that homozygous mutations in SMARCA4, PBRM1 and ARID2 were somatic. In one patient, homozygous germline variants were observed for SMARCC1 and SETD2 in chr3p22.1-3p14.2. These exhibited extended germline homozygosity and were in regions containing somatic mutations, leading to a loss of BAP1 and PBRM1 expression in MM cell line. Most protein-damaging variants were heterozygous in normal tissues. Heterozygous germline variants were often converted into hemizygous variants by mono-allelic deletion, and were rarely homozygous because of acquired uniparental disomy. Our findings imply that MM might develop through the somatic inactivation of mSWI/SNF complex subunits and/or histone modifiers, including BAP1, in subjects that have rare germline variants of these transcription regulators and/or transcription factors/co-factors, and in regions prone to mono-allelic deletion during oncogenesis.

Suppression of heme oxygenase-1 activity reduces airway hyperresponsiveness and inflammation in a mouse model of asthma.

OBJECTIVE: Carbon monoxide (CO) levels in expired gas are higher in patients with bronchial asthma than in healthy individuals. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme that catalyzes the degradation of heme to yield biliverdin, CO and free iron. Thus, HO-1 is implicated in the pathogenesis of bronchial asthma. However, whether HO-1 expression and activity in lung tissue are related to allergic airway inflammation remains unclear. We investigated whether expression of HO-1 is related to allergic airway inflammation in lungs and whether HO-1 could influence airway hyperresponsiveness and eosinophilia in mice sensitized to ovalbumin (OVA). METHODS: C57BL/6 mice immunized with OVA were challenged thrice with an aerosol of OVA every second day for 8 days. HO-1-positive cells were identified by immunostaining in lung tissue, and zinc protoporphyrin (Zn-PP), a competitive inhibitor of HO-1, was administered intraperitoneally to OVA-immunized C57BL/6 mice on day 23 (day before inhalation of OVA) and immediately before inhalation on the subsequent 4 days (total five doses). Mice were analyzed for effects of HO-1 on AHR, inflammatory cell infiltration and cytokine levels in lung tissue. Ethical approval was obtained from the concerned institutional review board. RESULTS: Number of HO-1-positive cells increased in the subepithelium of the bronchi after OVA challenge, and HO-1 localized to alveolar macrophages. Zn-PP clearly inhibited AHR, pulmonary eosinophilia and IL-5 and IL-13 expression in the lung tissue. CONCLUSION: Expression of HO-1 is induced in lung tissue during attacks of allergic bronchial asthma, and its activity likely amplifies and prolongs allergic airway inflammation.

Circulating tumor cells (CTCs) in malignant pleural mesothelioma (MPM).

PURPOSE: To investigate the diagnostic and prognostic value of circulating tumor cells (CTCs), a potential surrogate of micrometastasis, in malignant pleural mesothelioma (MPM). METHODS: We prospectively evaluated CTCs in 7.5 mL of peripheral blood sampled from patients with a suspicion of MPM. A semiautomated system was used to capture CTCs with an antibody against the epithelial cell adhesion molecule. RESULTS: Of 136 eligible patients, 32 were finally diagnosed with nonmalignant diseases (NM), and 104 had MPM. CTCs were detected in 32.7 % (34 of 104) of MPM patients but in only 9.4 % (3 of 32) of NM patients (P = 0.011). The CTC count was significantly higher in MPM patients than in NM patients (P = 0.007), and a receiver operating characteristic (ROC) curve analysis showed an insufficient capability of the CTC test in discrimination between MPM and NM, with an area under ROC curve of 0.623 (95 % confidence interval, 0.523-0.723; P = 0.036). Among MPM patients, CTCs were more frequently detected in patients with epithelioid subtype (39.7 %, 31 of 78) than in those with nonepithelioid subtypes (11.5 %, 3 of 26; P = 0.016). Positive CTCs (CTC count ≥ 1) were a significant factor to predict a poor prognosis among epithelioid patients (median overall survival, 22.3 months for positive CTCs vs. 12.6 months for negative CTCs; P = 0.004) and not in nonepithelioid patients (P = 0.649). A multivariate analysis showed that positive CTCs were a significant and independent factor to predict a poor prognosis (hazard ratio, 2.904; 95 % confidence interval, 1.530-5.511; P = 0.001) for epithelioid MPM patients. CONCLUSIONS: CTC was a promising marker in diagnosis and prediction of prognosis in MPM, especially in epithelioid MPM.

Soluble immune checkpoint factors reflect exhaustion of antitumor immunity and response to PD-1 blockade.

BACKGROUNDPrecise stratification of patients with non-small cell lung cancer (NSCLC) is needed for appropriate application of PD-1/PD-L1 blockade therapy.METHODSWe measured soluble forms of the immune-checkpoint molecules PD-L1, PD-1, and CTLA-4 in plasma of patients with advanced NSCLC before PD-1/PD-L1 blockade. A prospective biomarker-finding trial (cohort A) included 50 previously treated patients who received nivolumab. A retrospective observational study was performed for patients treated with any PD-1/PD-L1 blockade therapy (cohorts B and C), cytotoxic chemotherapy (cohort D), or targeted therapy (cohort E). Plasma samples from all patients were assayed for soluble immune-checkpoint molecules with a highly sensitive chemiluminescence-based assay.RESULTSNonresponsiveness to PD-1/PD-L1 blockade therapy was associated with higher concentrations of these soluble immune factors among patients with immune-reactive (hot) tumors. Such an association was not apparent for patients treated with cytotoxic chemotherapy or targeted therapy. Integrative analysis of tumor size, PD-L1 expression in tumor tissue (tPD-L1), and gene expression in tumor tissue and peripheral CD8+ T cells revealed that high concentrations of the 3 soluble immune factors were associated with hyper or terminal exhaustion of antitumor immunity. The combination of soluble PD-L1 (sPD-L1) and sCTLA-4 efficiently discriminated responsiveness to PD-1/PD-L1 blockade among patients with immune-reactive tumors.CONCLUSIONCombinations of soluble immune factors might be able to identify patients unlikely to respond to PD-1/PD-L1 blockade as a result of terminal exhaustion of antitumor immunity. Our data suggest that such a combination better predicts, along with tPD-L1, for the response of patients with NSCLC.TRIAL REGISTRATIONUMIN000019674.FUNDINGThis study was funded by Ono Pharmaceutical Co. Ltd. and Sysmex Corporation.

Complications associated with endobronchial ultrasound-guided transbronchial needle aspiration: a nationwide survey by the Japan Society for Respiratory Endoscopy.

BACKGROUND: With the recent widespread use of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), there have been occasional reports on complications associated with its use. Previous reviews on EBUS-TBNA have been limited to studies by skilled operators, thus the results may not always be applicable to recent clinical practice. To assess the safety of EBUS-TBNA for the staging and diagnosis of lung cancer in Japan, a nationwide survey on its current usage status and complications associated with its use was conducted by the Japan Society for Respiratory Endoscopy (JSRE). METHODS: A questionnaire about EBUS-TBNA performed between January 2011 and June 2012 was mailed to 520 JSRE-accredited facilities. RESULTS: Responses were obtained from 455 facilities (87.5%). During the study period, EBUS-TBNA was performed in 7,345 cases in 210 facilities (46.2%) using a convex probe ultrasound bronchoscope, for 6,836 mediastinal and hilar lesions and 275 lung parenchymal lesions. Ninety complications occurred in 32 facilities. The complication rate was 1.23% (95% confidence interval, 0.97%-1.48%), with hemorrhage being the most frequent complication (50 cases, 0.68%). Infectious complications developed in 14 cases (0.19%) (Mediastinitis, 7; pneumonia, 4; pericarditis, 1; cyst infection, 1; and sepsis, 1). Pneumothorax developed in 2 cases (0.03%), one of which required tube drainage. Regarding the outcome of the cases with complications, prolonged hospitalization was observed in 14 cases, life-threatening conditions in 4, and death in 1 (severe cerebral infarction) (mortality rate, 0.01%). Breakage of the ultrasound bronchoscope occurred in 98 cases (1.33%) in 67 facilities (31.9%), and that of the puncture needle in 15 cases (0.20%) in 8 facilities (3.8%). CONCLUSIONS: Although the complication rate associated with EBUS-TBNA was found to be low, severe complications, including infectious complications, were observed, and the incidence of device breakage was high. Since the use of EBUS-TBNA is rapidly expanding in Japan, an educational program for its safe performance should be immediately established.

A feasibility study of induction pemetrexed plus cisplatin followed by pleurectomy/decortication aimed at macroscopic complete resection for malignant pleural mesothelioma.

A prospective multi-institutional study has been initiated in Japan to evaluate the feasibility of induction chemotherapy using pemetrexed plus cisplatin, followed by pleurectomy/decortication aimed at macroscopic complete resection in patients with resectable malignant pleural mesothelioma. The study was initiated on September 2012, for which 24 patients will be recruited over a period of 2 years. The primary endpoint is the macroscopic complete resection rate, regardless of the surgical technique employed (i.e. pleurectomy/decortication or extrapleural pneumonectomy). The secondary endpoints are the pleurectomy/decortication rate, macroscopic complete resection rate by pleurectomy/decortication, pulmonary function at 3 months after surgery, adverse events, treatment-related mortality, response rate to chemotherapy and 3-year overall survival rate.

Frequent inactivation of the BAP1 gene in epithelioid-type malignant mesothelioma.

In the present study, we analyzed genomic alterations of BRCA1-associated protein 1 (BAP1) in 23 malignant mesotheliomas (MMs), 16 epithelioid and seven non-epithelioid, consisting of 18 clinical specimens and five established cell lines. In examining these samples for homozygous deletions and sequence-level mutations, we found biallelic BAP1 gene alterations in 14 of 23 MMs (61%). Seven of these 14 MMs had homozygous deletions of the partial or entire BAP1 gene, another five had sequence-level mutations, including small deletions, a nonsense mutation, and missense mutations with additional monoallelic deletions, and the remaining two had homozygous mutations without allelic loss. All but one of the 14 BAP1 gene mutations were found in the epithelioid-type MMs; BAP1 mutations were found in 13 of 16 epithelioid-type MMs, but in only one of seven non-epithelioid-type MMs (13/16 vs 1/7; P = 0.005). There was no BAP1 mRNA expression in MMs with biallelic deletion and repressed expression was confirmed in MM specimens with deletion/mutation as compared with Met5a, SV40-transformed normal mesothelial cells. Western blot showed that seven of eight epithelioid MMs analyzed were BAP1 negative. Immunostaining with anti-BAP1 antibody in normal lung tissues revealed clear nuclear staining of normal mesothelial cells. No nuclear staining was observed among BAP1 mutation-positive MM tumors, whereas nuclear staining was observed among BAP1 mutation-negative MM tumors. These results suggest that the lack of the tumor suppressor BAP1 may be more specifically involved in the pathogenesis of epithelioid MM rather than non-epithelioid MM, and would be useful for diagnosis of epithelioid-type MM.

Sphingosine suppresses mesothelioma cell proliferation by inhibiting PKC-δ and inducing cell cycle arrest at the G(0)/G(1) phase.

BACKGROUND/AIMS: Sphingosine regulates cellular differentiation, cell growth, and apoptosis. The present study aimed at understanding sphingosine-regulated mesothelioma cell proliferation. METHODS: Human malignant mesothelioma cells such as NCI-H28, NCI-H2052, NCI-H2452, and MSTO-211H cells were cultured. The siRNA to silence the protein kinase C (PKC)-δ-targeted gene was constructed and transfected into cells. MTT assay, cell cycle analysis using a flow cytometry, and cell-free PKC-δ assay were carried out. RESULTS: For all the cell types sphingosine inhibited cell growth in a concentration (1-100 µM)-dependent manner. The sphingosine effect was not prevented by rottlerin, an inhibitor of protein kinase C-δ (PKC-δ); conversely, rottlerin further enhanced the sphingosine effect or rottlerin suppressed mesothelioma cell growth without sphingosine. In the cell-free PKC assay, sphingosine attenuated PKC-δ activity. Knocking-down PKC-δ induced cell cycle arrest at the G0/G1 phase and inhibited cell growth. CONCLUSION: The results of the present study show that sphingosine suppressed mesothelioma cell proliferation by inhibiting PKC-δ, to induce cell cycle arrest at the G0/G1 phase.

AMP converted from intracellularly transported adenosine upregulates p53 expression to induce malignant pleural mesothelioma cell apoptosis.

BACKGROUND/AIMS: The present study investigated adenosine-induced apoptosis in human malignant pleural mesothelioma cells. METHODS: MTT assay, TUNEL staining, flow cytometry using propidium iodide and annexin V-FITC, real-time RT-PCR, Western blotting, and assay of caspase-3, -8, and -9 activities were carried out using malignant pleural mesothelioma cell lines such as NCI-H28, NCI-H2052, NCI-H2452, and MSTO-211H cells, and p53 or A(3) adenosine receptor was knocked-down by transfecting each siRNA into cells. RESULTS: Adenosine induced apoptosis in all the malignant pleural mesothelioma cells used here, independently of caspase activation. The adenosine effect was prevented by the adenosine transporter inhibitor dipyridamole, the adenosine kinase inhibitor ABT-702, or the A(3) adenosine receptor inhibitor MRS1191. Adenosine upregulated expression of the p53 mRNA and protein, that is abolished by ABT-702, but not by knocking-down A(3) adenosine receptor. Adenosine-induced apoptosis in NCI-H28 cells was significantly inhibited by knocking-down p53 and in part by knocking-down A(3) adenosine receptor. CONCLUSION: The results of the present study show that AMP converted from intracellularly transported adenosine upregulates p53 expression to induce caspase-independent apoptosis in malignant pleural mesothelioma cells and that A(3) adenosine receptor also participates partially in the apoptosis by the different mechanism.

A3 adenosine receptor-mediated p53-dependent apoptosis in Lu-65 human lung cancer cells.

BACKGROUND/AIMS: A(3) adenosine receptor mediates apoptosis in cancer cells via diverse signaling pathways. The present study examined A(3) adenosine receptor-mediated apoptosis in Lu-65 cells, a human giant cell lung carcinoma cell line. METHODS: MTT assay, TUNEL staining, real-time RT-PCR, Western blotting, and assay of caspase-3, -8, and -9 activities were carried out in Lu-65 cells, and A(3) adenosine receptor or p53 was knocked-down by transfecting each siRNA into cells. RESULTS: Extracellular adenosine induces Lu-65 cell apoptosis in a concentration (0.01-10 mM)-dependent manner, and the effect was inhibited by the A(3) adenosine receptor inhibitor MRS1191 or by knocking-down A(3) adenosine receptor or p53. Like adenosine, the A(3) adenosine receptor agonist 2-Cl-IB-MECA also induced Lu-65 cell apoptosis. Adenosine upregulated expression of p53 and Noxa mRNAs and activated caspase-3 and -9, but not caspase-8. Those adenosine effects were still inhibited by knocking-down A(3) adenosine receptor or p53. CONCLUSION: The results of the present study show that adenosine upregulates p53 expression via A(3) adenosine receptor, to promote p53-dependent Noxa gene transcription, causing activation of caspase-9 and the effector caspase-3 to induce Lu-65 cell apoptosis.

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.

Pathological and molecular biological approaches to early mesothelioma.

Malignant mesothelioma is an asbestos-related malignancy that arises primarily from mesothelial cells on the serosal surfaces of the pleural, peritoneal, and pericardial cavities. Malignant pleural mesothelioma (MPM) is most common, and its incidence is dramatically increasing worldwide as a result of widespread use of asbestos. Morphological discrimination between MPM and reactive mesothelial hyperplasia is difficult, and the most reliable pathological criterion for malignancy is mesothelial proliferation invading deeply into subpleural adipose tissues. To establish radical cure of MPM, it is crucial to find early-stage MPM of epithelial type, in which mesothelial proliferation is localized on the serosal surface of parietal pleura or limited within the submesothelial fibrous tissues of parietal pleura. The initial clinical presentation for patients with MPM is frequently dyspnea and/or chest pain due to large pleural effusion, and cytological analysis of pleural effusions is valuable to find patients with early-stage MPM of epithelial type. Recently, cytological features of MPM in pleural effusion, molecular markers for MPM, and genetic alternations of MPM have been reported. In this review, we discuss major issues on pathological and molecular biological approaches for diagnosis of early-stage MPM of epithelial type.

Heme oxygenase-1 promoter polymorphism is associated with risk of malignant mesothelioma.

BACKGROUND: Malignant mesothelioma is an aggressive tumor of serosal surfaces that is closely associated with asbestos exposure which induces oxidative stress. Heme oxygenase (HO)-1, a rate-limiting enzyme of heme degradation, plays a protective role against oxidative stress. The HO-1 gene promoter carries (GT)n repeats whose number is inversely related to transcriptional activity of the HO-1 gene. METHODS: To investigate the relationship between the length polymorphism of (GT)n repeats and mesothelioma susceptibility, we analyzed the HO-1 promoter in 44 asbestos-exposed subjects without mesothelioma and 78 asbestos-exposed subjects with mesothelioma using PCR-based genotyping. RESULTS: The number of repeats ranged from 16 to 38, with two peaks at 23 and 30 repeats. Polymorphisms of (GT)n repeats were grouped into two classes of alleles, short (S) (<24) and long (L) (≥24), and three genotypes: L/L, L/S, and S/S. The proportions of allele frequencies in class L as well as genotypic frequencies of L allele carriers (L/L and L/S) were significantly higher in the asbestos-exposed subjects with mesothelioma than in those without mesothelioma. CONCLUSION: The findings of this study suggest that long (GT)n repeats in the HO-1 gene promoter are associated with a higher risk of malignant mesothelioma in the Japanese population.

Practical approaches to diagnose and treat for T0 malignant pleural mesothelioma: a proposal for diagnostic total parietal pleurectomy.

Malignant pleural mesothelioma (MPM) remains suffering poor prognosis in spite of recent diagnostic and therapeutic progress. Although there is currently no established evidence, early diagnosis and early intervention may play a key role to improve prognosis of MPM, similarly to other malignancies. As pleural effusion is usually the first clinical sign of MPM, pleural effusion cytology is often the first diagnostic examination to be carried out. Since the sensitivity of pleural effusion cytology is approximately 60%, however, false-negative diagnosis is given to almost half of true MPM patients at this clinical step. One practical way to reduce the number of misdiagnosed MPM is to encourage performing thoracoscopic pleural biopsy unless definitive diagnosis other than MPM is established. There still remain a considerable number of patients with radiological/thoracoscopic T0 MPM who are misdiagnosed with nonspecific pleuritis after a complete investigation including thoracoscopic biopsies. Such patients will turn out to be malignant during follow-up period, although they have the best opportunity for long-term survival if only early therapeutic intervention is given. Currently, we are performing diagnostic total parietal pleurectomy in highly selected patients, who are characterized with strong clinical suspicion, positive pleural effusion cytology but uncertain pathological diagnosis, excellent cardiopulmonary reserve, and with written informed consent for highly invasive diagnostic surgery for pathologically unproven disease.

Arsenic trioxide induces apoptosis through JNK and ERK in human mesothelioma cells.

Malignant mesothelioma is an aggressive tumor of serosal surfaces, which is refractory to current treatment options. Arsenic trioxide (As2O3) is used clinically to treat acute promyelocytic leukemia, and also to inhibit proliferation of several solid tumors including hepatoma, esophageal, and gastric cancer in vitro. Here we found that As2O3 inhibited cell viability of a mesothelioma cell line, NCI-H2052. As2O3 induced apoptosis of NCI-H2052 cells, which was accompanied by activation of c-Jun NH2-terminal kinase (JNK)1/2, extracellular signal-regulated kinase (ERK)1/2, and caspase-3. zVAD-fmk, a broad-spectrum caspase inhibitor, inhibited As2O3-induced apoptosis and activation of caspase-3, but not that of JNK1/2 and ERK1/2. Small interfering RNAs (siRNAs) targeting JNK1/2 suppressed As2O3-induced caspase-3 activation and apoptosis, indicating that JNK1/2 regulate As2O3-induced apoptosis though caspase cascade. Furthermore, JNK1 siRNA abrogated As2O3-induced JNK2 phosphorylation and JNK2 siRNA abrogated As2O3-induced JNK1 phosphorylation, suggesting that JNK1 and JNK2 interact with each other. Moreover, JNK1 siRNA, but not JNK2 siRNA, abrogated As2O3-induced ERK1/2 phosphorylation. JNK2 siRNA together with PD98059, a specific MAPK/ERK kinase inhibitor, suppressed As2O3-induced apoptosis more significantly than JNK2 siRNA alone. These results indicated that As2O3 induces apoptosis of NCI-H2052 cells mainly through JNK1/2 activation, and that ERK1/2 is involved in As2O3-induced apoptosis when JNK1/2 are inactivated.

Clinical significance of pleural effusion mesothelin in malignant pleural mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is an aggressive malignant tumor of mesothelial origin associated with asbestos exposure. MPM has a limited response to conventional chemotherapy and radiotherapy, so early diagnosis of MPM is very important. This study investigated the pleural effusion mesothelin levels in patients with MPM and compared them to those of a population with a non-malignant pleuritis or lung cancer involving malignant pleural effusion. METHODS: The pleural effusion mesothelin concentrations were measured in 45 MPM patients and 53 non-MPM individuals (24 individuals with non-malignant pleural effusions and 29 individuals with lung cancer involving malignant pleural effusion). RESULTS: This study demonstrated that patients with MPM had significantly higher pleural effusion mesothelin levels than a population with non-malignant pleuritis or lung cancer involving malignant pleural effusion. The difference in overall survival between the groups with pleural effusion mesothelin levels lower and higher than the assumed cut-off of 10 nM was significant. CONCLUSIONS: The data suggest that the pleural effusion mesothelin concentration could be useful as an aid for the diagnosis of MPM.