Novel systemic therapy against malignant pleural mesothelioma

Malignant mediastinal mesothelioma treated with anlotinib: a case report and review of the literature

Malignant mesothelioma that originates from mediastinal (MMM) is a rare form of malignant pleural mesothelioma (MPM). The prognosis of advanced stage MPM was poor, and the traditional treatment was chemotherapy. Here, we present a patient with MMM that was treated with anlotinib, a multitargeted tyrosine kinase inhibitor (TKI) who had a 24-month progression-free survival (PFS). Further review of the literature showed that, despite some explorations of applying small-molecule multitargeted TKIs in the treatment of MPM, until today, no large series had a positive result. Anlotinib had been approved by the China Food and Drug Administration on treating non-small cell lung cancer, soft tissue sarcoma, renal cell carcinoma, and medullary thyroid cancer. We assumed that the ability of anlotinib to target more tyrosine kinase receptors than most of other TKIs could contribute to the long duration of PFS in this case, but further study is needed to further validate the efficacy of anlotinib in treatment of MPM.

Serum Extracellular Vesicle-Derived microRNAs as Potential Biomarkers for Pleural Mesothelioma in a European Prospective Study

Malignant pleural mesothelioma (MPM) is an aggressive cancer with a dismal prognosis. Early therapeutic interventions could improve patient outcomes. We aimed to identify a pattern of microRNAs (miRNAs) as potential early non-invasive markers of MPM. In a case-control study nested in the European Prospective Investigation into Cancer and Nutrition cohort, we screened the whole miRNome in serum extracellular vesicles (EVs) of preclinical MPM cases. In a subgroup of 20 preclinical samples collected five years prior MPM diagnosis, we observed an upregulation of miR-11400 (fold change (FC) = 2.6, adjusted p-value = 0.01), miR-148a-3p (FC = 1.5, p-value = 0.001), and miR-409-3p (FC = 1.5, p-value = 0.04) relative to matched controls. The 3-miRNA panel showed a good classification capacity with an area under the receiver operating characteristic curve (AUC) of 0.81 (specificity = 0.75, sensitivity = 0.70). The diagnostic ability of the model was also evaluated in an independent retrospective cohort, yielding a higher predictive power (AUC = 0.86). A signature of EV miRNA can be detected up to five years before MPM; moreover, the identified miRNAs could provide functional insights into the molecular changes related to the late carcinogenic process, preceding MPM development.

The extracellular matrix protein fibulin-3/EFEMP1 promotes pleural mesothelioma growth by activation of PI3K/Akt signaling

Malignant pleural mesothelioma (MPM) is an aggressive tumor with poor prognosis and limited therapeutic options. The extracellular matrix protein fibulin-3/EFEMP1 accumulates in the pleural effusions of MPM patients and has been proposed as a prognostic biomarker of these tumors. However, it is entirely unknown whether fibulin-3 plays a functional role on MPM growth and progression. Here, we demonstrate that fibulin-3 is upregulated in MPM tissue, promotes the malignant behavior of MPM cells, and can be targeted to reduce tumor progression. Overexpression of fibulin-3 increased the viability, clonogenic capacity and invasion of mesothelial cells, whereas fibulin-3 knockdown decreased these phenotypic traits as well as chemoresistance in MPM cells. At the molecular level, fibulin-3 activated PI3K/Akt signaling and increased the expression of a PI3K-dependent gene signature associated with cell adhesion, motility, and invasion. These pro-tumoral effects of fibulin-3 on MPM cells were disrupted by PI3K inhibition as well as by a novel, function-blocking, anti-fibulin-3 chimeric antibody. Anti-fibulin-3 antibody therapy tested in two orthotopic models of MPM inhibited fibulin-3 signaling, resulting in decreased tumor cell proliferation, reduced tumor growth, and extended animal survival. Taken together, these results demonstrate for the first time that fibulin-3 is not only a prognostic factor of MPM but also a relevant molecular target in these tumors. Further development of anti-fibulin-3 approaches are proposed to increase early detection and therapeutic impact against MPM.

Identification of Candidate Therapeutic Target Genes and Profiling of Tumor-Infiltrating Immune Cells in Pancreatic Cancer via Integrated Transcriptomic Analysis

Pancreatic cancer (PC) has a dismal prognosis despite advancing scientific and technological knowledge. The exploration of novel genes is critical to improving current therapeutic measures. This research is aimed at selecting hub genes that can act as candidate therapeutic target genes and as prognostic biomarkers in PC. Gene expression profiles of datasets GSE101448, GSE15471, and GSE62452 were extracted from the GEO database. The “limma” package was performed to select differentially expressed genes (DEGs) between PC and normal tissue samples in each dataset. Robust rank aggregation (RRA) algorithm was conducted to integrate multiple expression profiles and identify robust DEGs. GO analysis and KEGG analysis were conducted to identify the functional correlation of the DEGs. The CIBERSORT algorithm was conducted to estimate the immune cell composition of each tissue sample. STRING and Cytoscape were used to establish the protein-protein interaction (PPI) network. The cytoHubba plugin in Cytoscape was performed to identify hub genes. Survival analysis based on hub gene expression was performed with clinical information from TCGA database. 566 robust DEGs (338 upregulated genes and 226 downregulated genes) were identified. Tumor tissue had a higher infiltration of resting dendritic cells and tumor-associated macrophages (TAM), including M0, M1, and M2 macrophages, while infiltration levels of B memory cells, plasma cells, T cells CD8, T follicular helper cells, and NK cells in normal tissue were relatively higher. GO terms and KEGG pathway analysis results revealed enrichment in tumor-associated pathways, including the extracellular matrix organization, cell−substrate adhesion cytokine−cytokine receptor interaction, calcium signaling pathway, and glycine, serine, and threonine metabolism, to name a few. Finally, FN1, MSLN, PLAU, and VCAN were selected as hub genes. High expression of FN1, MSLN, PLAU, and VCAN in PC significantly correlated with poor prognosis. Integrated transcriptomic analysis was used to provide new insights into PC pathogenesis. FN1, MSLN, PLAU, and VCAN may be considered as novel biomarkers of PC.

An Updated Understanding of the Role of YAP in Driving Oncogenic Responses

Simple Summary

In 2020, the global cancer database GLOBOCAN estimated 19.3 million new cancer cases worldwide. The discovery of targeted therapies may help prognosis and outcome of the patients affected, but the understanding of the plethora of highly interconnected pathways that modulate cell transformation, proliferation, invasion, migration and survival remains an ambitious goal. Here we propose an updated state of the art of YAP as the key protein driving oncogenic response via promoting all those steps at multiple levels. Of interest, the role of YAP in immunosuppression is a field of evolving research and growing interest and this summary about the current pharmacological therapies impacting YAP serves as starting point for future studies.

Abstract

Yes-associated protein (YAP) has emerged as a key component in cancer signaling and is considered a potent oncogene. As such, nuclear YAP participates in complex and only partially understood molecular cascades that are responsible for the oncogenic response by regulating multiple processes, including cell transformation, tumor growth, migration, and metastasis, and by acting as an important mediator of immune and cancer cell interactions. YAP is finely regulated at multiple levels, and its localization in cells in terms of cytoplasm–nucleus shuttling (and vice versa) sheds light on interesting novel anticancer treatment opportunities and putative unconventional functions of the protein when retained in the cytosol. This review aims to summarize and present the state of the art knowledge about the role of YAP in cancer signaling, first focusing on how YAP differs from WW domain-containing transcription regulator 1 (WWTR1, also named as TAZ) and which upstream factors regulate it; then, this review focuses on the role of YAP in different cancer stages and in the crosstalk between immune and cancer cells as well as growing translational strategies derived from its inhibitory and synergistic effects with existing chemo-, immuno- and radiotherapies.

Drug Regimen for Patients after a Pneumonectomy

Pneumonectomy is an entire lung removal and is indicated for both malignant and benign diseases. Due to its invasiveness and postoperative complications, pneumonectomy is still associated with high mortality and morbidity. Appropriate postoperative management is crucial in pneumonectomy patients to improve quality of life and overall survival rates. Diverse drug regimens are under development to be used in adjuvant chemotherapy or to improve respiratory health after a pneumonectomy. The most common causes for a pneumonectomy are non-small cell lung cancer, malignant pleural mesothelioma, and tuberculosis; thus, an appropriate drug regimen is necessary. The uncommon incidence of pneumonectomy cases remains the major obstacle in studies of postoperative drug regimens. As the majority of current studies include post-lobectomy and post-segmentectomy patients, it is highly recommended that further research of postoperative drug regimens be focused on post-pneumonectomy patients.

Increased production of matrix metalloproteinase-7 (MMP-7) by asbestos exposure enhances tissue migration of human regulatory T-like cells

The effects of asbestos on immunocompetent cells have been investigated. In particular, attention was paid to regulatory T cell function, which was observed using the HTLV-1 immortalized human polyclonal T cell line MT-2. Exposure to asbestos (approximately more than 25 μg/mL for 1-3 day) induced apoptosis, and we observed an increase in regulatory T cell function and acceleration of the cell cycle with continuous exposure to low concentrations of asbestos (5-10 μg/mL for more than eight months). Furthermore, cDNA microarray analysis in this study revealed that expression of matrix metalloproteinase-7 (MMP-7) was markedly higher in exposed sublines compared to original MT-2 cells. It was determined that MMP-7 had no effect on Treg function, as determined by examination of sublines and by addition of recombinant MMP-7 and neutralizing antibodies or inhibitors of MMP-7. However, when examining melting of the extracellular matrix (an MMP-7-mediated event) or the extent to which the MT-2 parent strain or long-term exposed subline cells pass through a fibronectin-coated filter, more filter passes were observed for the subline. These results suggest that the effect of asbestos fibers on Treg cells results in excessive migration of the tumor microenvironment through hypersecretion of MMP-7 together with an increase in suppressive function and enhancement of cell cycle progression. Therefore, one possible way to prevent the development of asbestos-induced cancer is to reduce the function (including MMP-7 production) or amount of Treg cells by physiologically active substances or food ingredients. Alternatively, it may be possible to invoke immune checkpoint treatments when carcinogenesis occurs.

Modulation of Calretinin Expression in Human Mesothelioma Cells Reveals the Implication of the FAK and Wnt Signaling Pathways in Conferring Chemoresistance towards Cisplatin

Malignant mesothelioma (MM) is an aggressive asbestos-linked neoplasm, characterized by dysregulation of signaling pathways. Due to intrinsic or acquired chemoresistance, MM treatment options remain limited. Calretinin is a Ca²⁺-binding protein expressed during MM tumorigenesis that activates the FAK signaling pathway, promoting invasion and epithelial-to-mesenchymal transition. Constitutive calretinin downregulation decreases MM cells’ growth and survival, and impairs tumor formation in vivo. In order to evaluate early molecular events occurring during calretinin downregulation, we generated a tightly controlled IPTG-inducible expression system to modulate calretinin levels in vitro. Calretinin downregulation significantly reduced viability and proliferation of MM cells, attenuated FAK signaling and reduced the invasive phenotype of surviving cells. Importantly, surviving cells showed a higher resistance to cisplatin due to increased Wnt signaling. This resistance was abrogated by the Wnt signaling pathway inhibitor 3289-8625. In various MM cell lines and regardless of calretinin expression levels, blocking of FAK signaling activated the Wnt signaling pathway and vice versa. Thus, blocking both pathways had the strongest impact on MM cell proliferation and survival. Chemoresistance mechanisms in MM cells have resulted in a failure of single-agent therapies. Targeting of multiple components of key signaling pathways, including Wnt signaling, might be the future method-of-choice to treat MM.

Emerging therapies in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare cancer of the pleural surfaces frequently related to asbestos exposure. It is characterized by a poor prognosis even for patients treated with trimodality therapy, including surgery, chemotherapy and radiotherapy. Moreover, the majority of patients are not candidates for surgery due to disease advanced stage or medical comorbidities. For these patients, the survival rate is even lower and few therapeutic options are currently available. Nevertheless, many interesting novel approaches are under investigation, among which immunotherapy represents one of the most promising emerging strategies. In this review, we will discuss the role of new therapeutic options, particularly immunotherapy, and present the results of the most important and promising clinical trials.

The Emerging Role of YAP/TAZ in Tumor Immunity

Yes-associated protein (YAP)/WW domain-containing transcription regulator 1 (TAZ) is an important transcriptional regulator and effector of the Hippo signaling pathway that has emerged as a critical determinant of malignancy in many human tumors. YAP/TAZ expression regulates the cross-talk between immune cells and tumor cells in the tumor microenvironment through its influence on T cells, myeloid-derived suppressor cells, and macrophages. However, the mechanisms underlying these effects are poorly understood. An improved understanding of the role of YAP/TAZ in tumor immunity is essential for exploring innovative tumor treatments and making further breakthroughs in antitumor immunotherapy. This review primarily focuses on the role of YAP/TAZ in immune cells, their interactions with tumor cells, and how this impacts on tumorigenesis, progression, and therapy resistance.

Return to work after surgical treatment for malignant pleural mesothelioma: report of a case

We report the case of a 56-year-old woman who underwent pleural biopsy to identify the cause of the right pleural effusion. The pathological diagnosis was epithelial malignant pleural mesothelioma. The patient worked as a junior high school teacher and strongly hoped for continuing work. Thus, we performed pleurectomy/decortication (P/D) as a curative surgery. The operative findings showed pleural thickening that in the lower lobe of the lung. Thus, peeling of the lower lobe was performed. Pleural biopsy was only performed on the upper and middle lobes. As a result, the operation was limited P/D. The pathological findings showed a small number of mesothelioma cells in the upper and middle lobes. The patient received four courses of cisplatin plus pemetrexed systemic chemotherapy after surgery. Continuous maintenance chemotherapy using pemetrexed has been performed until the time of writing. At present, she has continued her work for 6 years after the operation and has extended her retirement age without recurrence.

Nuclear grading, BAP1, mesothelin and PD-L1 expression in malignant pleural mesothelioma: prognostic implications

For malignant pleural mesothelioma (MPM), histopathological subtype is one of the most important prognostic factors. Several immunohistochemical stains whose expressions have possible therapeutic implications have been identified in MPM such as BAP1, mesothelin and PD-L1. The aim of our work was to evaluate the clinical significance and prognostic implications of BAP1, mesothelin and PD-L1 expression in 117 patients with a diagnosis of MPM who were diagnosed in our institution between 2002 and 2017. We also correlated this immunohistochemical profile to a recently described nuclear grading and to histopathological subtype. Mesothelin expression, BAP1 loss and PD-L1 expression were associated with histopathological subtype (p < 0.0001), BAP1 loss was more frequent in epithelioid subtype whereas PD-L1 expression was more frequent in non-epithelioid subtype. For epithelioid MPM, BAP1 expression was associated with overall survival (p = 0.034), with a longer survival when BAP1 expression is lost. Necrosis and nuclear grading are associated with overall survival (p = 0.0048 and <0.0001, respectively), with longer survival when necrosis was absent and for grade I. For non-epithelioid MPM, overall survival was not related to clinical, histopathological or immunohistochemical expression of BAP1, mesothelin or PD-L1. In multivariate analysis, grade I for nuclear grading was an independent prognostic factor associated with overall survival (p < 0.0001). In epithelioid and non-epithelioid MPM, we analysed overall survival in subgroups with combined mesothelin, BAP1 and PD-L1 expression. In epithelioid MPM, BAP1 retained/mesothelin negativity/PD-L1 > 1%, and BAP1 retained/mesothelin positivity/PD-L1 > 1% profiles, are associated with shorter overall survival. In non-epithelioid MPM, BAP1 loss/mesothelin negativity/PD-L1 > 1% is associated with shorter overall survival. Our work confirms that nuclear grading in epithelioid MPM is a strong and independent prognosis factor. Moreover, this study on several promising immunohistochemical stains whose expressions have possible therapeutic implications identifies subgroups with a poor prognosis.

Update on International Cooperative Groups Studies in Thoracic Malignancies: The Emergence of Immunotherapy

Cancer cooperative groups have historically played a critical role in the advancement of non-small-cell lung cancer therapy. Representatives from cooperative groups worldwide convene at the International Lung Cancer Congress annually. The International Lung Cancer Congress had its 17th anniversary in the summer of 2016. The present review highlights the thoracic malignancy studies discussed by presenters. The included studies are merely a sample of the trials of thoracic malignancies ongoing globally.

Inhibition of yes-associated protein down-regulates PD-L1 (CD274) expression in human malignant pleural mesothelioma

Although tumour PD‐L1 (CD274) expression had been used as a predictive biomarker in checkpoint immunotherapy targeting the PD1/PD‐L1 axis in various cancers, the regulation of PD‐L1 (CD274) expression is unclear. Yes‐associated protein (YAP), an important oncogenic protein in Hippo signalling pathway, reportedly promotes cancer development. We investigated whether inhibition of YAP down‐regulates PD‐L1 (CD274) in human malignant pleural mesothelioma (MPM). Western blotting showed that 2 human MPM cell lines (H2052 and 211H) had increased PD‐L1 protein expression compared to H290, MS‐1 and H28 cells. In H2052 and 211H cells, PD‐L1 mRNA expression was significantly increased compared to other MPM cell lines; YAP knockdown by small interfering RNA decreased PD‐L1 protein and mRNA expression. Forced overexpression of the YAP gene increased PD‐L1 protein expression in H2452 cells. Chromatin immunoprecipitation (ChIP) assay showed the precipitation of PD‐L1 enhancer region encompassing 2 putative YAP‐TEAD‐binding sites in H2052 cells. We found that, in human MPM tissue microarray samples, YAP and PD‐L1 concurrently expressed in immunohistochemistry stain (n = 70, P < .05, chi‐square). We conclude that PD‐L1 is correlated with YAP expression, and inhibition of YAP down‐regulates PD‐L1 expression in human MPM. Further study of how YAP regulates PD‐L1 in MPM is warranted.

Chemotherapy treatment in malignant pleural mesothelioma: a difficult history

Malignant pleural mesothelioma (MPM) is a rare neoplasm that typically arises from mesothelial surfaces of the pleural cavity. Despite treatment improvements, it carries a dismal prognosis. The majority of patients either have unresectable disease or are not candidates for surgery due to medical comorbidities or old age. For such patients, chemotherapy (CT) represents the gold-standard treatment. To date, combination CT with cisplatin plus pemetrexed represents the most widely used regimen in first-line setting for patients with unresectable MPM. Other first-line options are currently available, including the use of raltitrexed instead of pemetrexed combined with platinum. In this review, we discuss the role of CT in MPM mainly focusing on the results of the trials conducted in first-line setting.

Amatuximab and novel agents targeting mesothelin for solid tumors

Mesothelin (MSLN) is considered a promising target for cancer therapy. Originally extracted in 1992 after the immunization of mice with a human ovarian cancer (OC) cell line and cloned in 1996, MSLN seems to be involved in cell adhesion and metastasis. MSLN is prevalent in mesothelia tissues but is expressed in several human cancers, such as OC, pancreatic cancer, mesothelioma, and lung cancer. Amatuximab (MORAb-009) is a mouse-human chimeric monoclonal antibody with a selective affinity for MSLN. The principal mechanism of action comprises inhibition of binding of MSLN with the antigen CA125/MUC16. The highest phase of development is actually a Phase II trial (MORAb-009-201, Europe). In this review, we describe the mechanism of action of amatuximab and other MSLN-targeting novel drugs, along with a discussion about the expected efficacy, safety, and toxicity of this promising group of agents and implications for future research and clinical practice.

Patterns of care and survival among patients with malignant mesothelioma in the United States

BACKGROUND

Mesothelioma is a rare malignancy that is associated with poor survival. This study aimed to describe the patterns of care and subsequent survival among malignant mesothelioma patients in the United States, while adjusting for patient demographics and comorbidities.

METHODS

A random sample of patients diagnosed with histologically confirmed mesothelioma in 2011, as reported to the National Cancer Institute's Surveillance Epidemiology and End Results program, were included. Logistic regression and Cox proportional hazard regression were utilized to identify factors associated with receipt of therapy and all-cause mortality, respectively, among patients with pleural mesothelioma.

RESULTS

This study included 389 patients with pleural mesothelioma and 53 patients with non-pleural mesothelioma. Almost a third (29.3%) of the pleural patients and 21.5% of the non-pleural patients received no therapy. Additionally, approximately 60% of both patient groups received systemic therapy. Among pleural mesothelioma patients, receipt of therapy was less likely among older patients. Median survival was 9 months among the pleural patients and 18 months among the non-pleural patients. Receipt of either surgery or systemic therapy and particularly the combination of these two modalities was associated with better all-cause survival. Additionally, among pleural mesothelioma patients, younger age and lower socioeconomic status were found to be associated with better all-cause survival. Comorbidity score was not found to be associated with receipt of treatment nor was it independently associated with survival among pleural mesothelioma patients.

CONCLUSION

These findings indicate the need for efforts to ensure equitable application of currently available therapies to all patients.