Formalin-Fixed Paraffin-Embedded Proteomics of Malignant Mesothelioma and New Candidate Biomarkers Thioredoxin and Superoxide Dismutase 2 for Immunohistochemistry.

The pathogenesis of malignant mesothelioma (MM) has been extensively investigated, focusing on stress derived from reactive oxygen species. We aimed to identify diagnostic biomarkers of MM by analyzing proteins in formalin-fixed paraffin-embedded specimens using liquid chromatography-mass spectrometry. We extracted proteins from formalin-fixed paraffin-embedded sections of MM tissues (n = 7) and compared their profiles with those of benign mesothelial tissues (n = 4) and alveolar tissue (n = 1). Proteomic data were statistically assessed and profiled using principal component analysis. We were successful in the classification of MM and healthy tissue. The levels of superoxide dismutase 2 (SOD2), an enzyme that converts superoxide anion into oxygen and hydrogen peroxide, and thioredoxin (TXN), which plays a crucial role in reducing disulfide bonds in proteins, primarily contributed to the classification. Other redox-related proteins, such as pyruvate dehydrogenase subunit X, and ceruloplasmin also contributed to the classification. Protein-protein interaction analysis demonstrated that these proteins play essential roles in MM pathogenesis. Immunohistochemistry revealed that TXN levels were significantly lower, whereas SOD2 levels were significantly higher in MM and lung cancer tissues than in controls. Proteomic profiling suggested that MM tissues experienced increased exposure to hydrogen peroxide and other reactive oxygen species. Combining immunohistochemistry for TXN and SOD2 allows for differentiation among MM, lung cancer, and control tissues; hence, TXN and SOD2 may be promising MM biomarkers and therapeutic targets.

Novel chimeric antigen receptor-expressing T cells targeting the malignant mesothelioma-specific antigen sialylated HEG1.

The selection of highly specific target antigens is critical for the development of clinically efficient and safe chimeric antigen receptors (CARs). In search of diagnostic marker for malignant mesothelioma (MM), we have established SKM9-2 monoclonal antibody (mAb) which recognizes a MM-specific molecule, sialylated Protein HEG homolog 1 (HEG1), with high specificity and sensitivity. In this study, to develop a novel therapeutic approach against MM, we generated SKM9-2 mAb-derived CARs that included the CD28 (SKM-28z) or 4-1BB (SKM-BBz) costimulatory domain. SKM-28z CAR-T cells showed continuous growth and enhanced Tim-3, LAG-3, and PD-1 expression in vitro, which might be induced by tonic signaling caused by self-activation; however, these phenotypes were not observed in SKM-BBz CAR-T cells. In addition, SKM-BBz CAR-T cells exhibited slightly stronger in vitro killing activity against MM cell lines than SKM-28z CAR-T cells. More importantly, only SKM-BBz CAR-T cells, but not SKM-28z CAR-T cells, significantly inhibited tumor growth in vivo in a MM cell line xenograft mouse model. Gene expression profiling and reporter assays revealed differential signaling pathway activation; in particular, SKM-BBz CAR-T cells exhibited enhanced NF-kB signaling and reduced NFAT activation. In addition, SKM-BBz CAR-T cells showed upregulation of early memory markers, such as TCF7 and CCR7, as well as downregulation of pro-apoptotic proteins, such as BAK1 and BID, which may be associated with phenotypical and functional differences between SKM-BBz and SKM-28z CAR-T cells. In conclusion, we developed novel SKM9-2-derived CAR-T cells with the 4-1BB costimulatory domain, which could provide a promising therapeutic approach against refractory MM.

Stemness and hybrid epithelial-mesenchymal profiles guide peritoneal dissemination of malignant mesothelioma and pseudomyxoma peritonei.

Intrabdominal dissemination of malignant mesothelioma (MM) and pseudomyxoma peritonei (PMP) is poorly characterized with respect to the stemness window which malignant cells activate during their reshaping on the epithelial-mesenchymal (E/M) axis. To gain insights into stemness properties and their prognostic significance in these rarer forms of peritoneal metastases (PM), primary tumor cultures from 55 patients selected for cytoreductive surgery with hyperthermic intraperitoneal chemotherapy were analyzed for cancer stem cells (CSC) by aldehyde dehydrogenase 1 (ALDH1) and spheroid formation assays, and for expression of a set of plasticity-related genes to measure E/M transition (EMT) score. Intratumor heterogeneity was also analyzed. Samples from PM of colorectal cancer were included for comparison. Molecular data were confirmed using principal component and cluster analyses. Associations with survival were evaluated using Kaplan-Meier and Cox regression models. The activity of acetylsalicylic acid (ASA), a stemness modifier, was tested in five cultures. Significantly increased amounts of ALDH1bright-cells identified high-grade PMP, and discriminated solid masses from ascitic/mucin-embedded tumor cells in both forms of PM. Epithelial/early hybrid EMT scores and an early hybrid expression pattern correlated with pluripotency factors were significantly associated with early peritoneal progression (p = .0343 and p = .0339, respectively, log-rank test) in multivariable models. ASA impaired spheroid formation and increased cisplatin sensitivity in all five cultures. These data suggest that CSC subpopulations and hybrid E/M states may guide peritoneal spread of MM and PMP. Stemness could be exploited as targetable vulnerability to increase chemosensitivity and improve patient outcomes. Additional research is needed to confirm these preliminary data.

Air pollution and survival in patients with malignant mesothelioma and asbestos-related lung cancer: a follow-up study of 1591 patients in South Korea.

BACKGROUND: Despite significant advancements in treatments such as surgery, radiotherapy, and chemotherapy, the survival rate for patients with asbestos-related cancers remains low. Numerous studies have provided evidence suggesting that air pollution induces oxidative stress and inflammation, affecting acute respiratory diseases, lung cancer, and overall mortality. However, because of the high case fatality rate, there is limited knowledge regarding the effects of air pollution exposures on survival following a diagnosis of asbestos-related cancers. This study aimed to determine the effect of air pollution on the survival of patients with malignant mesothelioma and asbestos-related lung cancer. METHODS: We followed up with 593 patients with malignant mesothelioma and 998 patients with lung cancer identified as asbestos victims between 2009 and 2022. Data on five air pollutants-sulfur dioxide, carbon monoxide, nitrogen dioxide, fine particulate matter with a diameter < 10 µm, and fine particulate matter with a diameter < 2.5 µm-were obtained from nationwide atmospheric monitoring stations. Cox proportional hazard models were used to estimate the association of cumulative air pollutant exposure with patient mortality, while adjusting for potential confounders. Quantile-based g-computation was used to assess the combined effect of the air pollutant mixture on mortality. RESULTS: The 1-, 3-, and 5-year survival rates for both cancer types decreased with increasing exposure to all air pollutants. The estimated hazard ratios rose significantly with a 1-standard deviation increase in each pollutant exposure level. A quartile increase in the pollutant mixture was associated with a 1.99-fold increase in the risk of malignant mesothelioma-related mortality (95% confidence interval: 1.62, 2.44). For lung cancer, a quartile increase in the pollutant mixture triggered a 1.87-fold increase in the mortality risk (95% confidence interval: 1.53, 2.30). CONCLUSION: These findings support the hypothesis that air pollution exposure after an asbestos-related cancer diagnosis can negatively affect patient survival.

Contributions of Dr. Wick to the pathology of diseases of the lung and pleura.

The curriculum vitae of Dr. Mark R. Wick contains 57 peer-reviewed publications, 3 editorials, 6 book chapters and a whole book dedicated to diseases of the lung and pleura. It is remarkable that such productivity should represent only a small portion of the overall output of Dr. Wick, which includes (at last count) 341 original peer-review publications, 119 invited review articles, 93 book chapters, 42 editorials, 3 society-related position papers, 18 books and 2 interactive video disks. Yet, his contributions to the literature in pulmonary and pleural pathology have been significant and influential and have established for him a national and international reputation as one of the leading experts in pulmonary pathology. Herein, it is my privilege to recount the various publications contributed by Dr. Wick to this topic, which span the gamut from transplant pathology to neoplastic diseases of the lung and pleura.

Preliminary evaluation of antiproliferative and apoptotic activities of novel indolin-2-one derivatives.

Indole-based agents are frequently used in targeted or supportive therapy of several cancers. In this study, we investigated the anticancer properties of originally synthesized novel indolin-2-one derivatives (6a-d) against Malignant Mesothelioma, Breast cancer, and Colon Cancer cells. Our results revealed that all derivatives were effectively delayed cell proliferation by inhibiting the ERK1/2, AKT, and STAT3 signaling pathways in a concentration-dependent manner. Additionally, these variants induced cell cycle arrest in the S phase, accompanied by elevated levels of p21 and p27 expressions. Derivatives also initiated mitochondrial apoptosis through the upregulation of Bax and downregulation of Bcl-2 proteins, leading to the activation of caspase 3 and PARP cleavage in exposed cells. Remarkably, three of the indolin-2-one derivatives displayed significant selectivity towards Breast and Colon Cancer cells, with compound 6d promising as the most potent and wide spectral one for all cancer cell lines.

Carcinogenicity of asbestos-free talc and talcum powder: A systematic review of the epidemiological evidence after the 2006 monograph of the International Agency for Research on Cancer.

BACKGROUND: in 2006, the International Agency for Research on Cancer (IARC) concluded that the evidence of carcinogenicity for asbestos-free talc was inadequate (group 3), whereas perineal use of talcum powder was classified as possibly carcinogenic (group 2B). OBJECTIVES: to assess whether later studies provide more solid information on the carcinogenic risk from asbestos-free talc and talcum powder and a better characterization of exposure. DESIGN: systematic review. METHODS: cohort studies of talc miners and millers exposed to asbestos-free talc, as well as cohort and case-control studies reporting cancer risk in talc powder consumers published from 2006 onwards were identified through PubMed and reference lists. Pooled analyses were included, but not reviews and meta-analyses. In the case of repeatedly reported studies, the article with the longest follow-up or the largest number of observed cases was selected for data abstraction. Notice was taken of studies which were both reported individually and included in pooled analyses. RESULTS: publications meeting inclusion criteria were: 2 cohort studies on talc miners and millers, 10 cohort studies on talcum powder users (4 of which estimated ovarian cancer risk), and 14 case-control studies (13 on ovarian and 1 on endometrial cancer) on the risk from talcum powder use. No excess cancer mortality has been reported among asbestos-free talc miners and millers. Case-control studies consistently led to estimates of ovarian cancer excesses associated with the use of perineal talcum powder (odds ratios up to 1.5). Most studies quantifying exposure also provided evidence of a dose-response relationship. Individual cohort studies estimated hazard ratios (HR) just above 1. In an analysis of pooled cohorts for a total of 3,112 cases, the HR for women with patent reproductive tract was 1.13 (95%CI 1.01-1.26) with a correlation between HR and frequency of use (p for trend 0.03). In all cohort studies, the perineal use of talcum powder was measured only once in the early phases of follow-up, thus producing an inaccurate measure of cumulative exposure. Results of epidemiological studies regarding cancer risk in other organs are limited and inconsistent. CONCLUSIONS: epidemiological studies updated or published after IARC 2006 evaluation indicate that: no increase in cancer risk is apparent among miners and millers of asbestos-free talc; risk for ovarian cancer increases following the perineal use of commercial talcum powder. A correlation between indicators of quantity of use and cancer risk is suggested by a number of studies. The composition of talcum powders considered in such studies is not known.

[Survival analysis of 37 cases of malignant mesothelioma].

Objective: To explore the relationship between clinicopathological features, treatment and prognosis of patients with malignant mesothelioma, and provide theoretical basis for the prevention and treatment of malignant mesothelioma. Methods: In November 2022, the clinical data of 37 patients with malignant mesothelioma diagnosed in Qingdao Central Hospital from July 2014 to November 2022 were retrospectively analyzed, and the prognostic factors were analyzed by Kaplan-Meier and log-rank tests. Results: The median age of the 37 patients was 66 years old, all patients were confirmed by pathology. The median survival time of all patients was 30.00 months. The 1-year, 2-year, 3-year and 5-year cumulative survival rates were 70.27% (26/37), 48.65% (18/37), 16.22% (6/37) and 13.51% (5/37), respectively. Compared with different treatments, the median survival time of palliative care patients was 5.00 months, which was significantly lower than that of operation group (30.33 months), chemotherapy group (30.00 months), surgery combined with chemotherapy group (30.00 months) and chemotherapy combined with bevacizumab targeted therapy group (47.42 months) (P<0.05). Gender, age (≥60 years old or <60 years old), smoking history, occupational exposure history, disease site, and surgical history were not factors affecting the survival of malignant mesothelioma patients (P>0.05) . Conclusion: The clinical symptoms of malignant mesothelioma are not specific, but early initiation of treatment can still prolong survival, and chemotherapy combined with anti-vascular targeted therapy shows better therapeutic effect.

BRCA1 haploinsufficiency impairs iron metabolism to promote chrysotile-induced mesothelioma via ferroptosis resistance.

Malignant mesothelioma (MM) is still a social burden associated with asbestos exposure. Local iron accumulation thereby represents the major pathogenesis, followed by oxidative DNA strand breaks and genomic alterations in the mesothelium. BRCA1 is a critical component of homologous recombination repair directed to DNA double-stranded breaks, whereas BRCA1 germline mutation is an established risk for breast/ovarian cancer, its role in MM development remains to be elucidated. Murine Brca1 mutant models so far have not reproduced human phenotypes. However, a rat Brca1 mutant model (Mut; L63X/+ ) recently reproduced them at least partially. Here we describe the differential induction of MM in Brca1 mutant rats by intraperitoneal injection of chrysotile or crocidolite. Only Mut males injected with chrysotile revealed a promotional effect on mesothelial carcinogenesis in comparison with wild-type and/or females, with all the MMs Brca1 haploinsufficient. Array-based comparative genomic hybridization of MMs disclosed a greater extent of chromosomal deletions in Brca1 mutants, including Cdkn2a/2b accompanied by Tfr2 amplification, in comparison with wild-type tumors. Mutant MMs indicated iron metabolism dysregulation, such as an increase in catalytic Fe(II) and Ki67-index as well as a decrease in Fe(III) and ferritin expression. Simultaneously, mutant MMs revealed ferroptosis resistance by upregulation of Slc7A11 and Gpx4. At an early carcinogenic stage of 4 weeks, induced Brca1 expression in mesothelial cells was significantly suppressed in chrysotile/Mut in comparison with crocidolite/Mut, whereas significant preference to iron with a decrease in Fe(III) has been already established. In conclusion, chrysotile exposure can be a higher risk for MM in BRCA1 mutant males, considering the rat results.

A postmortem case control study of asbestos burden in lungs of malignant mesothelioma cases.

BACKGROUND: Asbestos lung content is regarded as the most reliable tool for causal attribution of malignant mesothelioma (MM) to previous asbestos exposures. However, there is a lack of studies on asbestos burden in lungs of MM patients in comparison with healthy individuals. This study aims to provide such a comparison, investigating, as well, differences in asbestos lung burden with sex and time trends. METHODS: Asbestos lung content has been assessed on formalin-fixed lung fragments using scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS) on individuals deceased from MM (cases) and healthy subjects without any lung disease who died from violent causes (controls) between 2005 and 2023. RESULTS: Asbestos and asbestos bodies (ABs) were found, respectively, in 73.7% and 43.2% of cases and in 28 and 22% of controls; in MM cases the most represented asbestos types were crocidolite and amosite, whereas in controls it was tremolite-actinolite asbestos. The concentration of both asbestos fibers and ABs was statistically significantly higher in MM cases compared to controls. The mean asbestos fibers width was also significantly higher in cases than controls. Males and females with MM showed similar asbestos and ABs concentrations, but females had higher concentrations of chrysotile, and significantly lower fibers width compared to males. Time trends show that MM lung asbestos concentrations decreased starting in 2011. DISCUSSION: The results suggest a correlation between asbestos burden in lungs and MM risk. The different concentration of chrysotile, as well as the different width of asbestos fibers in MM males and females might reflect a sex difference in response of the lung microenvironment to inhaled asbestos. Finally, this study provides the first pathological evidence of the effect of the ban of asbestos use, demonstrating a significant decrease of asbestos lung content after 2011.

miR-142-3p Suppresses Invasion and Adhesion of Mesothelioma Cells by Downregulating ITGAV.

INTRODUCTION: Malignant mesothelioma is an aggressive cancer associated with asbestos exposure. Currently, the efficacy of therapeutics is limited in malignant mesothelioma, and developing more effective therapies is the need of the hour. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), have attracted attention as therapeutic targets. To explore potential therapeutic targets, we focused on miR-142-3p expression, which was found to be significantly downregulated in mesothelioma cell lines in our previous study. METHODS: Mesothelioma cell lines and tissues were validated for expression of miR-142-3p or integrin subunit alpha-V (ITGAV). We transfected mesothelioma cell lines with miR-142-3p mimic and ITGAV siRNA and analyzed their biological functions. RESULTS: We found that miR-142-3p was significantly downregulated in mesothelioma tissues. Transfection with miR-142-3p mimic significantly suppressed cell proliferation, migration, and invasion. Bioinformatics analysis of potential targets of miR-142-3p identified ITGAV. Membrane ITGAV expression in mesothelioma cell lines was confirmed using immunocytochemistry. ITGAV was significantly upregulated in mesothelioma tissues. Moreover, transfection of miR-142-3p mimics into mesothelioma cell lines significantly suppressed ITGAV expression, indicating that miR-142-3p targets ITGAV. Next, ITGAV siRNA transfection into mesothelioma cell lines inhibited cell proliferation, migration, and invasion. Further investigation of cell adhesion mechanisms showed that the miR-142-3p/ITGAV axis specifically affects mesothelioma cell adhesion via vitronectin in the extracellular matrix. CONCLUSION: This study proposed that the miR-142-3p/ITGAV axis is involved in tumor progression in malignant mesothelioma.

Mechanisms and shapes of causal exposure-response functions for asbestos in mesotheliomas and lung cancers.

This paper summarizes recent insights into causal biological mechanisms underlying the carcinogenicity of asbestos. It addresses their implications for the shapes of exposure-response curves and considers recent epidemiologic trends in malignant mesotheliomas (MMs) and lung fiber burden studies. Since the commercial amphiboles crocidolite and amosite pose the highest risk of MMs and contain high levels of iron, endogenous and exogenous pathways of iron injury and repair are discussed. Some practical implications of recent developments are that: (1) Asbestos-cancer exposure-response relationships should be expected to have non-zero background rates; (2) Evidence from inflammation biology and other sources suggests that there are exposure concentration thresholds below which exposures do not increase inflammasome-mediated inflammation or resulting inflammation-mediated cancer risks above background risk rates; and (3) The size of the suggested exposure concentration threshold depends on both the detailed time patterns of exposure on a time scale of hours to days and also on the composition of asbestos fibers in terms of their physiochemical properties. These conclusions are supported by complementary strands of evidence including biomathematical modeling, cell biology and biochemistry of asbestos-cell interactions in vitro and in vivo, lung fiber burden analyses and epidemiology showing trends in human exposures and MM rates.

An investigation of the internal morphology of asbestos ferruginous bodies: constraining their role in the onset of malignant mesothelioma.

BACKGROUND: Asbestos is a fibrous mineral that was widely used in the past. However, asbestos inhalation is associated with an aggressive type of cancer known as malignant mesothelioma (MM). After inhalation, an iron-rich coat forms around the asbestos fibres, together the coat and fibre are termed an "asbestos ferruginous body" (AFB). AFBs are the main features associated with asbestos-induced MM. Whilst several studies have investigated the external morphology of AFBs, none have characterised the internal morphology. Here, cross-sections of multiple AFBs from two smokers and two non-smokers are compared to investigate the effects of smoking on the onset and growth of AFBs. Morphological and chemical observations of AFBs were undertaken by transmission electron microscopy, energy dispersive x-ray spectroscopy and selected area diffraction. RESULTS: The AFBs of all patients were composed of concentric layers of 2-line or 6-line ferrihydrite, with small spherical features being observed on the outside of the AFBs and within the cross-sections. The spherical components are of a similar size to Fe-rich inclusions found within macrophages from mice injected with asbestos fibres in a previous study. As such, the spherical components composing the AFBs may result from the deposition of Fe-rich inclusions during frustrated phagocytosis. The AFBs were also variable in terms of their Fe, P and Ca abundances, with some layers recording higher Fe concentrations (dense layers), whilst others lower Fe concentrations (porous layers). Furthermore, smokers were found to have smaller and overall denser AFBs than non-smokers. CONCLUSIONS: The AFBs of smokers and non-smokers show differences in their morphology, indicating they grew in lung environments that experienced disparate conditions. Both the asbestos fibres of smokers and non-smokers were likely subjected to frustrated phagocytosis and accreted mucopolysaccharides, resulting in Fe accumulation and AFB formation. However, smokers' AFBs experienced a more uniform Fe-supply within the lung environment compared to non-smokers, likely due to Fe complexation from cigarette smoke, yielding denser, smaller and more Fe-rich AFBs. Moreover, the lack of any non-ferrihydrite Fe phases in the AFBs may indicate that the ferritin shell was intact, and that ROS may not be the main driver for the onset of MM.

Curcumin potentiates the ErbB receptors inhibitor Afatinib for enhanced antitumor activity in malignant mesothelioma.

Several attempts have been made to develop targeted therapies for malignant mesothelioma (MM), an aggressive tumour with a poor prognosis. In this study we evaluated whether Curcumin (CUR) potentiated the antitumor activity of the ErbB receptors inhibitor Afatinib (AFA) on MM, employing cell lines cultured in vitro and mice bearing intraperitoneally transplanted, syngeneic MM cells. The rationale behind this hypothesis was that CUR could counteract mechanisms of acquired resistance to AFA. We analysed CUR and AFA effects on MM cell growth, cell cycle, autophagy, and on the modulation of tumour-supporting signalling pathways.This study demonstrated that, as compared to the individual compounds, the combination of AFA + CUR had a stronger effect on MM progression which can be ascribed either to increased tumour cell growth inhibition or to an enhanced pro-apoptotic effect. These results warrant future studies aimed at further exploring the therapeutic potential of AFA + CUR-based combination regimens for MM treatment.

Serum Calretinin and Genetic Variability as a Prognostic and Predictive Factor in Malignant Mesothelioma.

Calretinin is a promising diagnostic biomarker for malignant mesothelioma (MM), but less is known about its prognostic role. Our aim was to evaluate the association between serum calretinin concentration or genetic factors and the survival or outcome of cisplatin-based chemotherapy in MM. Our study included 265 MM patients. Serum calretinin concentration was determined using ELISA. Patients were genotyped for seven polymorphisms in CALB2, E2F2, MIR335, NRF1, and SEPTIN7 using competitive allele-specific PCR. Nonparametric tests, logistic regression, and survival analysis were used for statistical analysis. Higher serum calretinin concentration was associated with shorter progression-free (PFS) (HR = 1.18 (1.02-1.37), p = 0.023) and overall survival (OS) (HR = 1.20 (1.03-1.41), p = 0.023), but the association was not significant after adjusting for clinical factors (HR = 1.05 (0.85-1.31), p = 0.653 and HR = 1.06 (0.84-1.34), p = 0.613, respectively). SEPTIN7 rs3801339 and MIR335 rs3807348 were associated with survival even after adjustment (HR = 1.76 (1.17-2.64), p = 0.007 and HR = 0.65 (0.45-0.95), p = 0.028, respectively). Calretinin concentration was higher in patients who progressed after treatment with cisplatin-based chemotherapy (1.68 vs. 0.45 ng/mL, p = 0.001). Calretinin concentration above 0.89 ng/mL was associated with shorter PFS and OS from the start of chemotherapy (HR = 1.88 (1.28-2.77), p = 0.001 and HR = 1.91 (1.22-2.97), p = 0.004, respectively), even after adjusting for clinical factors (p < 0.05). MIR335 rs3807348 was associated with a better response to chemotherapy (OR = 2.69 (1.17-6.18), p = 0.020). We showed that serum calretinin is associated with survival and chemotherapy treatment outcomes in MM and could serve as a predictive biomarker.

Metabolic Effects of New Glucose Transporter (GLUT-1) and Lactate Dehydrogenase-A (LDH-A) Inhibitors against Chemoresistant Malignant Mesothelioma.

Malignant mesothelioma (MM) is a highly aggressive and resistant tumor. The prognostic role of key effectors of glycolytic metabolism in MM prompted our studies on the cytotoxicity of new inhibitors of glucose transporter type 1 (GLUT-1) and lactate dehydrogenase-A (LDH-A) in relation to ATP/NAD+ metabolism, glycolysis and mitochondrial respiration. The antiproliferative activity of GLUT-1 (PGL13, PGL14) and LDH-A (NHI-1, NHI-2) inhibitors, alone and in combination, were tested with the sulforhodamine-B assay in peritoneal (MESO-II, STO) and pleural (NCI-H2052 and NCI-H28) MM and non-cancerous (HMEC-1) cells. Effects on energy metabolism were measured by both analysis of nucleotides using RP-HPLC and evaluation of glycolysis and respiration parameters using a Seahorse Analyzer system. All compounds reduced the growth of MM cells in the µmolar range. Interestingly, in H2052 cells, PGL14 decreased ATP concentration from 37 to 23 and NAD+ from 6.5 to 2.3 nmol/mg protein. NHI-2 reduced the ATP/ADP ratio by 76%. The metabolic effects of the inhibitors were stronger in pleural MM and in combination, while in HMEC-1 ATP reduction was 10% lower compared to that of the H2052 cells, and we observed a minor influence on mitochondrial respiration. To conclude, both inhibitors showed cytotoxicity in MM cells, associated with a decrease in ATP and NAD+, and were synergistic in the cells with the highest metabolic modulation. This underlines cellular energy metabolism as a potential target for combined treatments in selected cases of MM.

Prognostic Value of EMT Gene Signature in Malignant Mesothelioma.

Malignant mesothelioma (MESO) consists of epithelioid, biphasic, and sarcomatoid subtypes with different epithelial-mesenchymal transition (EMT) phenotypes. We previously identified a panel of four MESO EMT genes correlating with an immunosuppressive tumor microenvironment and poor survival. In this study, we investigated the correlation between these MESO EMT genes, the immune profile, and the genomic and epigenomic alterations to identify potential therapeutic targets to prevent or reverse the EMT process. Using multiomic analysis, we observed that the MESO EMT genes were positively correlated with hypermethylation of epigenetic genes and loss of CDKN2A/B expression. MESO EMT genes such as COL5A2, ITGAV, SERPINH1, CALD1, SPARC, and ACTA2 were associated with upregulation of TGF-ß signaling, hedgehog signaling, and IL-2-STAT5 signaling and downregulation of the IFN-α and IFN-γ response. Immune checkpoints such as CTLA4, CD274 (PD-L1), PDCD1LG2 (PD-L2), PDCD1 (PD-1), and TIGIT were upregulated, while LAG3, LGALS9, and VTCN1 were downregulated with the expression of MESO EMT genes. CD160, KIR2DL1, and KIR2DL3 were also broadly downregulated with the expression of MESO EMT genes. In conclusion, we observed that the expression of a panel of MESO EMT genes was associated with hypermethylation of epigenetic genes and loss of expression of CDKN2A and CDKN2B. Expression of MESO EMT genes was associated with downregulation of the type I and type II IFN response, loss of cytotoxicity and NK cell activity, and upregulation of specific immune checkpoints, as well as upregulation of the TGF-ß1/TGFBR1 pathway.

Malignant mesothelioma of the peritoneum mimicking primary peritonitis carcinomatosis.

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Diffuse peritoneal deciduosis in pregnancy.

Ectopic decidua is a rare benign condition, believed to be associated with excessive progesterone stimulation such as in multiple gestations as in our case, it's usually asymptomatic and found incidentally during caesarean section. The lesions involute spontaneously in the postpartum period; therefore it usually doesn't require any therapeutic interventions. This condition could induce anxiety to surgeons intra-operatively, because of resemblance of more sinister lesions such as: carcinomatosis and granulomas. We report a clinical case of diffuse peritoneal deciduosis, identified during an emergency caesarean section, performed at 33 weeks of gestation, for a transverse lie, twins DCDA pregnancy in active labor.

Phase I Study of Tremelimumab Monotherapy or in Combination With Durvalumab in Japanese Patients With Advanced Solid Tumors or Malignant Mesothelioma.

BACKGROUND: The primary objective of this phase I, open-label trial was to assess safety and tolerability of tremelimumab monotherapy and combination therapy with durvalumab in Japanese patients with advanced cancer. Tremelimumab is a fully human monoclonal antibody against CTLA-4 in clinical trials; durvalumab is a monoclonal antibody against PD-L1 for the treatment of bladder and lung cancer. METHODS: In part 1, tremelimumab 3 or 10 mg/kg was given every 4 weeks (Q4W) for 6 doses, and thereafter every 12 weeks until discontinuation (n = 8); subsequently tremelimumab 10 mg/kg Q4W for 6 doses/Q12W and thereafter until discontinuation was administered in 41 patients with malignant pleural or peritoneal mesothelioma (MPM). In part 2, tremelimumab 10 mg/kg (Q4W for 6 doses followed by Q12W for 3 doses) was given in combination with durvalumab 15 mg/kg (Q4W for 13 doses) in cohort 1 (n = 4). In cohort 2 (n = 6), tremelimumab 1 mg/kg (Q4W for 4 doses) was given in combination with durvalumab 20 mg/kg (Q4W for 4 doses followed by 10 mg/kg Q2W for 22 doses), while in cohort 3 (n = 6), fixed-dose tremelimumab 75 mg Q4W for 4 doses plus durvalumab 1500 mg Q4W for 13 doses was given. RESULTS: In part 1, no dose-limiting toxicities (DLTs) for tremelimumab 3 or 10 mg/kg (Q4W for 6 doses/Q12W thereafter until discontinuation) were observed. Six (75%) patients reported treatment-related adverse events (trAEs). In the MPM dose-expansion cohort, 38 (92.7%) patients reported trAEs. In part 2, one DLT (Grade 4 myasthenia gravis) was reported for tremelimumab 10 mg/kg (Q4W for 6 doses/Q12W for 3 doses) plus durvalumab 15 mg/kg (Q4W for 13 doses). One DLT (Grade 4 hyperglycemia) was reported for tremelimumab 75 mg (Q4W for 4 doses) plus durvalumab 1500 mg (Q4W for 13 doses). Fourteen (87.5%) patients reported trAEs. Tremelimumab demonstrated low immunogenicity; 1 (16.7%) patient developed antidrug antibodies. CONCLUSION: Tremelimumab 10 mg/kg (Q4W/Q12W), tremelimumab 1 mg/kg (Q4W) plus durvalumab 20 mg/kg (Q4W/10 mg/kg Q2W), and fixed-dose tremelimumab 75 mg (Q4W) plus durvalumab 1500 mg (Q4W) were safe and tolerable.ClinicalTrials.gov Identifier: NCT02141347 (https://clinicaltrials.gov/ct2/show/NCT02141347).