RESUMO
INTRODUCTION: Small cell lung cancer (SCLC) is mostly diagnosed in stage III-IV patients and associated with poor prognosis. To date, surgery is no gold-standard treatment for any SCLC stage and evidence is lacking whether it is beneficial. Here we investigate the impact of surgery, with special attention to stage III SCLC patients, sub-stages and treatment combinations. METHODS: The overall survival (OS) and cancer-specific survival (CSS) of 33,198 SCLC patients (SEER database) were analyzed retrospectively, using various statistical analyses, including propensity score matching (PSM), recursive partitioning, and sequential landmark analyses. RESULTS: Independent of stage, the OS of patients with surgery-including treatments was almost always better than without surgery. This holds true for stage I-II patients, even after PMS analysis (p < 0.017). The same was found for stage IV patients that underwent surgery plus chemotherapy vs. chemotherapy alone (p = 0.013 after PSM). Stage III patients showed a robust improvement in OS and CSS after surgery (OS: 18 vs.13 months) or surgery plus chemotherapy (OS: 20 vs.15 months) as confirmed by well-balanced PSM and sequential landmark analyses of long-term survivors. More detailed analyses using two independent approaches showed prolonged OS in T3-4/N0-1 and T1-2/N2 stage III patients after surgery or surgery plus chemotherapy. Importantly, primary site surgery had a major survival advantage over surgery at regional sites (p < 0.003). CONCLUSION: Our study demonstrates that selected patients of all stages, including stage III T3-4/N0-1 and T1-2/N2, can benefit greatly from surgery-including treatments. Thus, surgery should be included into hospital treatment recommendations for specifically selected SCLC patients. Condensed abstract Primary resection in patients with stage III SCLC needs re-evaluation. Selected patients with stage III SCLC benefit significantly from surgery. Patients with T3-4/N0-1 and T1-2/N2 stage III SCLC should be considered for surgery.
RESUMO
Protein tyrosine phosphatase receptor zeta 1 (PTPRZ1) is a transmembrane tyrosine phosphatase (TP) expressed in endothelial cells and required for stimulation of cell migration by vascular endothelial growth factor A165 (VEGFA165 ) and pleiotrophin (PTN). It is also over or under-expressed in various tumor types. In this study, we used genetically engineered Ptprz1-/- and Ptprz1+/+ mice to study mechanistic aspects of PTPRZ1 involvement in angiogenesis and investigate its role in lung adenocarcinoma (LUAD) growth. Ptprz1-/- lung microvascular endothelial cells (LMVEC) have increased angiogenic features compared with Ptprz1+/+ LMVEC, in line with the increased lung angiogenesis and the enhanced chemically induced LUAD growth in Ptprz1-/- compared with Ptprz1+/+ mice. In LUAD cells isolated from the lungs of urethane-treated mice, PTPRZ1 TP inhibition also enhanced proliferation and migration. Expression of beta 3 (ß3 ) integrin is decreased in Ptprz1-/- LMVEC, linked to enhanced VEGF receptor 2 (VEGFR2), c-Met tyrosine kinase (TK) and Akt kinase activities. However, only c-Met and Akt seem responsible for the enhanced endothelial cell activation in vitro and LUAD growth and angiogenesis in vivo in Ptprz1-/- mice. A selective PTPRZ1 TP inhibitor, VEGFA165 and PTN also activate c-Met and Akt in a PTPRZ1-dependent manner in endothelial cells, and their stimulatory effects are abolished by the c-Met TK inhibitor (TKI) crizotinib. Altogether, our data suggest that low PTPRZ1 expression is linked to worse LUAD prognosis and response to c-Met TKIs and uncover for the first time the role of PTPRZ1 in mediating c-Met activation by VEGFA and PTN.
Assuntos
Adenocarcinoma de Pulmão , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores , Animais , Camundongos , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Células Endoteliais/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tirosina/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismoRESUMO
Kirsten rat sarcoma virus (KRAS)-mutant cancers are frequent, metastatic, lethal, and largely undruggable. While interleukin (IL)-1ß and nuclear factor (NF)-κB inhibition hold promise against cancer, untargeted treatments are not effective. Here, we show that human KRAS-mutant cancers are addicted to IL-1ß via inflammatory versican signaling to macrophage inhibitor of NF-κB kinase (IKK) ß. Human pan-cancer and experimental NF-κB reporter, transcriptome, and proteome screens reveal that KRAS-mutant tumors trigger macrophage IKKß activation and IL-1ß release via secretory versican. Tumor-specific versican silencing and macrophage-restricted IKKß deletion prevents myeloid NF-κB activation and metastasis. Versican and IKKß are mutually addicted and/or overexpressed in human cancers and possess diagnostic and prognostic power. Non-oncogene KRAS/IL-1ß addiction is abolished by IL-1ß and TLR1/2 inhibition, indicating cardinal and actionable roles for versican and IKKß in metastasis.
RESUMO
Malignant pleural mesothelioma (MPM) is a rare, incurable cancer of the mesothelial cells lining the lungs and the chest wall that is mainly caused by asbestos inhalation. The molecular mechanisms of mesothelial carcinogenesis are still unclear despite comprehensive studies of the mutational landscape of MPM, and the most frequently mutated genes BAP1, NF2, CDKN2A, TP53, and TSC1 cannot cause MPM in mice in a standalone fashion. Although KRAS pathway alterations were sporadically detected in older studies employing targeted sequencing, they have been largely undetected by next generation sequencing. We recently identified KRAS mutations and copy number alterations in a significant proportion of MPM patients. Here, we review and analyze multiple human datasets and the published literature to show that, in addition to KRAS, multiple other genes of the KRAS pathway are perturbed in a significant proportion of patients with MPM.
RESUMO
The high plasticity of lung epithelial cells, has for many years, confounded the correct identification of the cell-of-origin of lung adenocarcinoma (LUAD), one of the deadliest malignancies worldwide. Here, we employ lineage-tracing mouse models to investigate the cell of origin of Eml4-Alk LUAD, and show that Club and Alveolar type 2 (AT2) cells give rise to tumours. We focus on Club cell originated tumours and find that Club cells experience an epigenetic switch by which they lose their lineage fidelity and gain an AT2-like phenotype after oncogenic transformation. Single-cell transcriptomic analyses identified two trajectories of Club cell evolution which are similar to the ones used during lung regeneration, suggesting that lung epithelial cells leverage on their plasticity and intrinsic regeneration mechanisms to give rise to a tumour. Together, this study highlights the role of Club cells in LUAD initiation, identifies the mechanism of Club cell lineage infidelity, confirms the presence of these features in human tumours, and unveils key mechanisms conferring LUAD heterogeneity.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Animais , Diferenciação Celular/genética , Transformação Celular Neoplásica/patologia , Células Epiteliais/patologia , Humanos , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , CamundongosRESUMO
KRAS (KRAS proto-oncogene, GTPase) inhibitors perform less well than other targeted drugs in vitro and fail clinical trials. To investigate a possible reason for this, we treated human and murine tumor cells with KRAS inhibitors deltarasin (targeting phosphodiesterase-δ), cysmethynil (targeting isoprenylcysteine carboxylmethyltransferase), and AA12 (targeting KRASG12C), and silenced/overexpressed mutant KRAS using custom-designed vectors. We showed that KRAS-mutant tumor cells exclusively respond to KRAS blockade in vivo, because the oncogene co-opts host myeloid cells via a C-C-motif chemokine ligand 2 (CCL2)/interleukin-1 beta (IL-1ß)-mediated signaling loop for sustained tumorigenicity. Indeed, KRAS-mutant tumors did not respond to deltarasin in C-C motif chemokine receptor 2 (Ccr2) and Il1b gene-deficient mice, but were deltarasin-sensitive in wild-type and Ccr2-deficient mice adoptively transplanted with wild-type murine bone marrow. A KRAS-dependent pro-inflammatory transcriptome was prominent in human cancers with high KRAS mutation prevalence and poor predicted survival. Our findings support that in vitro cellular systems are suboptimal for anti-KRAS drug screens, as these drugs function to suppress interleukin-1 receptor 1 (IL1R1) expression and myeloid IL-1ß-delivered pro-growth effects in vivo. Moreover, the findings support that IL-1ß blockade might be suitable for therapy for KRAS-mutant cancers.
RESUMO
Malignant pleural mesothelioma (MPM) arises from mesothelial cells lining the pleural cavity of asbestos-exposed individuals and rapidly leads to death. MPM harbors loss-of-function mutations in BAP1, NF2, CDKN2A, and TP53, but isolated deletion of these genes alone in mice does not cause MPM and mouse models of the disease are sparse. Here, we show that a proportion of human MPM harbor point mutations, copy number alterations, and overexpression of KRAS with or without TP53 changes. These are likely pathogenic, since ectopic expression of mutant KRASG12D in the pleural mesothelium of conditional mice causes epithelioid MPM and cooperates with TP53 deletion to drive a more aggressive disease form with biphasic features and pleural effusions. Murine MPM cell lines derived from these tumors carry the initiating KRASG12D lesions, secondary Bap1 alterations, and human MPM-like gene expression profiles. Moreover, they are transplantable and actionable by KRAS inhibition. Our results indicate that KRAS alterations alone or in accomplice with TP53 alterations likely play an important and underestimated role in a proportion of patients with MPM, which warrants further exploration.
Assuntos
Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Neoplasias Pleurais , Proteínas Proto-Oncogênicas p21(ras) , Animais , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mesotelioma/genética , Mesotelioma/patologia , Mesotelioma Maligno/genética , Mesotelioma Maligno/patologia , Camundongos , Neoplasias Pleurais/genética , Neoplasias Pleurais/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismoRESUMO
BACKGROUND: Survival after curative resection of early-stage lung adenocarcinoma (LUAD) varies and prognostic biomarkers are urgently needed. METHODS: Large-format tissue samples from a prospective cohort of 200 patients with resected LUAD were immunophenotyped for cancer hallmarks TP53, NF1, CD45, PD-1, PCNA, TUNEL and FVIII, and were followed for a median of 2.34 (95% CI 1.71-3.49)â years. RESULTS: Unsupervised hierarchical clustering revealed two patient subgroups with similar clinicopathological features and genotype, but with markedly different survival: "proliferative" patients (60%) with elevated TP53, NF1, CD45 and PCNA expression had 50% 5-year overall survival, while "apoptotic" patients (40%) with high TUNEL had 70% 5-year survival (hazard ratio 2.23, 95% CI 1.33-3.80; p=0.0069). Cox regression and machine learning algorithms including random forests built clinically useful models: a score to predict overall survival and a formula and nomogram to predict tumour phenotype. The distinct LUAD phenotypes were validated in The Cancer Genome Atlas and KMplotter data, and showed prognostic power supplementary to International Association for the Study of Lung Cancer tumour-node-metastasis stage and World Health Organization histologic classification. CONCLUSIONS: Two molecular subtypes of LUAD exist and their identification provides important prognostic information.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Humanos , Neoplasias Pulmonares/patologia , Fenótipo , Prognóstico , Antígeno Nuclear de Célula em Proliferação/genética , Estudos ProspectivosRESUMO
Aims Diagnosis of Adenotonsillar Hypertrophy (ATH), the leading cause of pediatric Obstructive Sleep Apnea (OSA), depends on physical exam via Brodsky's staging of tonsils. This study investigates the associations of ATH with patient parameters, and balances in-office tonsil hypertrophy appraisal against true organ mass. Materials and Methods A prospective cohort was formed of 103 children operated for ATH, and 31 matched controls. Demographic, clinical and tympanographic data, as well as Complete Blood Count (CBC) indices were compared. Absolute and relative to total body weight tonsil specimen mass were correlated with Brodsky's score. Results Tonsillar size indices were significantly raised in ATH patients. Elevated leukocytes (P = 0.012) and increased neutrophil percentage (P = 0.025) conveyed higher ATH risk. Subjective evaluation of tonsils graded 1 or 2 correlated significantly with absolute (P = 0.001) and relative (P = 0.006) objective measurements. Brodsky's score 3 and 4 displayed marginal significant association with relative (P = 0.050) but not with true (P = 0.989) mass. Conclusion An occult hematologic inflammatory response was detected in ATH children. Clinical estimation of severely hypertrophic tonsils should be adjusted for total body weight. Trial Registration Number: NCT03541434 (clinicaltrials.gov).
RESUMO
Epidemiological studies established an association between chronic inflammation and higher risk of cancer. Inhibition of proteolytic enzymes represents a potential treatment strategy for cancer and prevention of cancer metastasis. Cathepsin C (CatC) is a highly conserved lysosomal cysteine dipeptidyl aminopeptidase required for the activation of pro-inflammatory neutrophil serine proteases (NSPs, elastase, proteinase 3, cathepsin G and NSP-4). NSPs are locally released by activated neutrophils in response to pathogens and non-infectious danger signals. Activated neutrophils also release neutrophil extracellular traps (NETs) that are decorated with several neutrophil proteins, including NSPs. NSPs are not only NETs constituents but also play a role in NET formation and release. Although immune cells harbor large amounts of CatC, additional cell sources for this protease exists. Upregulation of CatC expression was observed in different tissues during carcinogenesis and correlated with metastasis and poor patient survival. Recent mechanistic studies indicated an important interaction of tumor-associated CatC, NSPs, and NETs in cancer development and metastasis and suggested CatC as a therapeutic target in a several cancer types. Cancer cell-derived CatC promotes neutrophil recruitment in the inflammatory tumor microenvironment. Because the clinical consequences of genetic CatC deficiency in humans resulting in the elimination of NSPs are mild, small molecule inhibitors of CatC are assumed as safe drugs to reduce the NSP burden. Brensocatib, a nitrile CatC inhibitor is currently tested in a phase 3 clinical trial as a novel anti-inflammatory therapy for patients with bronchiectasis. However, recently developed CatC inhibitors possibly have protective effects beyond inflammation. In this review, we describe the pathophysiological function of CatC and discuss molecular mechanisms substantiating pharmacological CatC inhibition as a potential strategy for cancer treatment.
Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Catepsina C/antagonistas & inibidores , Catepsina C/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Animais , Catepsina C/química , Armadilhas Extracelulares/efeitos dos fármacos , Armadilhas Extracelulares/metabolismo , Humanos , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Serina Proteases/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/fisiologiaRESUMO
The cellular origin of lung adenocarcinoma remains a focus of intense research efforts. The marked cellular heterogeneity and plasticity of the lungs, as well as the vast variety of molecular subtypes of lung adenocarcinomas perplex the field and account for the extensive variability of experimental results. While most experts would agree on the cellular origins of other types of thoracic tumours, great controversy exists on the tumour-initiating cells of lung adenocarcinoma, since this histologic subtype of lung cancer arises in the distal pulmonary regions where airways and alveoli converge, occurs in smokers as well as nonsmokers, is likely caused by various environmental agents, and is marked by vast molecular and pathologic heterogeneity. Alveolar type II, club, and their variant cells have all been implicated in lung adenocarcinoma progeny and the lineage hierarchies in the distal lung remain disputed. Here we review the relevant literature in this rapidly expanding field, including results from mouse models and human studies. In addition, we present a case for club cells as cells of origin of lung adenocarcinomas that arise in smokers.
Assuntos
Adenocarcinoma de Pulmão , Adenocarcinoma , Neoplasias Pulmonares , Animais , Células Epiteliais , Humanos , Camundongos , Fumar/efeitos adversosRESUMO
BACKGROUND: MicroRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. One of the miRNAs that has been shown to play a role in various pathologies like cancer, neurological disorders and cardiovascular diseases is miRNA-26b. However, these studies only demonstrated rather ambiguous associations without revealing a causal relationship. Therefore, the aim of this study is to establish and validate a mouse model which enables the elucidation of the exact role of miRNA-26b in various pathologies. RESULTS: A miRNA-26b-deficient mouse model was established using homologous recombination and validated using PCR. miRNA-26b-deficient mice did not show any physiological abnormalities and no effects on systemic lipid levels, blood parameters or tissue leukocytes. Using next generation sequencing, the gene expression patterns in miRNA-26b-deficient mice were analyzed and compared to wild type controls. This supported the already suggested role of miRNA-26b in cancer and neurological processes, but also revealed novel associations of miRNA-26b with thermogenesis and allergic reactions. In addition, detailed analysis identified several genes that seem to be highly regulated by miRNA-26b, which are linked to the same pathological conditions, further confirming the role of miRNA-26b in these pathologies and providing a strong validation of our mouse model. CONCLUSIONS: miRNA-26b plays an important role in various pathologies, although causal relationships still have to be established. The described mouse model of miRNA-26b deficiency is a crucial first step towards the identification of the exact role of miRNA-26b in various diseases that could identify miRNA-26b as a promising novel diagnostic or even therapeutic target in a broad range of pathologies.
Assuntos
MicroRNAs , Neoplasias , Transcriptoma , Animais , Modelos Animais de Doenças , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , MicroRNAs/genética , RNA MensageiroRESUMO
Lung adenocarcinoma (LADC) is the leading cause of cancer death worldwide and is largely inflicted by carcinogens contained in tobacco smoke. The generation of cell lines mimicking traits of human LADC will profoundly advance our understanding of the pathobiology of the disease, as they offer an easy and valuable tool to study the cellular and molecular aspects of carcinogenesis. Here we describe a detailed protocol for the generation of such cell lines, following the exposure of experimental mouse strains to different tobacco carcinogens and isolation of the resulting lung tumors.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Animais , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Fumar/efeitos adversos , Fumar/metabolismo , Fumar/patologiaRESUMO
Herein we elaborated on methods to load cellular vesicles (CVs) and to incorporate cholesterol (Chol) and PEG lipids in their membrane, for enhancing the potential of such engineered CVs (e-CVs) as drug carriers. Hybrids formed by fusion between PEGylated liposomes (PEG-LIP) and CVs were evaluated as alternatives to e-CV, for the first time. Freeze-thawing cycles (FT) and incubation protocols were tested, and vesicle fusion was monitored by FRET dilution. B16F10, hCMEC/D3, and LLC cells were used for e-CV or hybrid development, and FITC-dextran as a model hydrophilic drug. Results show that dehydration rehydration vesicle (DRV) method is optimal for highest CV loading and integrity, while optimal protocols for Chol/PEG enrichment were identified. FT was found to be more efficient than incubation for hybrid formation. Interestingly, despite their high Chol content, CVs had very low integrity that was not increased by enrichment with Chol, but only after PEG coating; e-CVs demonstrated higher integrity than hybrids. Vesicle uptake by hCMEC cells is in the order: LIP < e-CVs < Hybrids ≤ CVs (verified by confocal microscopy); the higher PEG content of e-CVs is possibly the reason for their reduced cell uptake. While CV and hybrid uptake are highly caveolin-dependent, e-CVs mostly follow clathrin-dependent pathways. In vivo and ex vivo results show that brain accumulation of hybrids is only slightly higher that of CVs, indicating that the surface PEG content of hybrids is not sufficient to prevent uptake by macrophages of the reticuloendothelial system. Taking together with the fact that subjection of CVs to FT cycles reduced their cellular uptake, it is concluded that PEGylated e-CVs are better than hybrids as brain-targeted drug carriers.
Assuntos
Sistemas de Liberação de Medicamentos , Polietilenoglicóis , Encéfalo/metabolismo , Portadores de Fármacos , LipossomosRESUMO
Transcription factors can serve as links between tumor microenvironment signaling and oncogenesis. Interferon regulatory factor 9 (IRF9) is recruited and expressed upon interferon stimulation and is dependent on cofactors that exert in tumor-suppressing or oncogenic functions via the JAK-STAT pathway. IRF9 is frequently overexpressed in human lung cancer and is associated with decreased patient survival; however, the underlying mechanisms remain to be elucidated. Here, we used stably transduced lung adenocarcinoma cell lines (A549 and A427) to overexpress or knockdown IRF9. Overexpression led to increased oncogenic behavior in vitro, including enhanced proliferation and migration, whereas knockdown reduced these effects. These findings were confirmed in vivo using lung tumor xenografts in nude mice, and effects on both tumor growth and tumor mass were observed. Using RNA sequencing, we identified versican (VCAN) as a novel downstream target of IRF9. Indeed, IRF9 and VCAN expression levels were found to be correlated. We showed for the first time that IRF9 binds at a newly identified response element in the promoter region of VCAN to regulate its transcription. Using an siRNA approach, VCAN was found to enable the oncogenic properties (proliferation and migration) of IRF9 transduced cells, perhaps with CDKN1A involvement. The targeted inhibition of IRF9 in lung cancer could therefore be used as a new treatment option without multimodal interference in microenvironment JAK-STAT signaling.
RESUMO
Lung cancer is the leading cancer killer worldwide, imposing grievous challenges for patients and clinicians. The incidence of lung adenocarcinoma (LUAD), the main histologic subtype of lung cancer, is still increasing in current-, ex-, and even non-smokers, whereas its five-year survival rate is approximately 15% as the vast majority of patients usually present with advanced disease at the time of diagnosis. The generation of novel drugs targeting key disease driver mutations has created optimism for the treatment of LUAD, but, as these mutations are not universal, this therapeutic line benefits only a subset of patients. More recently, the advent of targeted immunotherapies and their documented clinical efficacy in many different cancers, including LUAD, have started to change cancer management. Immunotherapies have been developed in order to overcome the cancer's ability to develop mechanisms of immune resistance, i.e., to adapt to and evade the host inflammatory and immune responses. Identifying a cancer's immune resistance mechanisms will likely advance the development of personalized immunotherapies. This review examines the key pathways of immune resistance at play in LUAD and explores therapeutic strategies which can unleash potent antitumor immune responses and significantly improve therapeutic efficacy, quality of life, and survival in LUAD.
RESUMO
Malignant pleural mesothelioma (MPM) is an aggressive cancer, associated with poor prognosis. We assessed the feasibility of patient-derived cell cultures to serve as an ex vivo model of MPM. Patient-derived MPM cell cultures (n=16) exhibited stemness features and reflected intratumour and interpatient heterogeneity. A subset of the cells were subjected to high-throughput drug screening and coculture assays with cancer-specific cytotoxic T cells and showed diverse responses. Some of the biphasic MPM cells were capable of processing and presenting the neoantigen SSX-2 endogenously. In conclusion, patient-derived MPM cell cultures are a promising and faithful ex vivo model of MPM.