Use of non-small cell lung cancer multicellular tumor spheroids to study the impact of chemotherapy

BACKGROUND

Lung cancers represent the main cause of cancer related-death worldwide. Recently, immunotherapy alone or in combination with chemotherapy has deeply impacted the therapeutic care leading to an improved overall survival. However, relapse will finally occur, with no efficient second line treatment so far. New therapies development based on the comprehension of resistance mechanisms is necessary. However, the difficulties to obtain tumor samples before and after first line treatment hamper to clearly understand the consequence of these molecules on tumor cells and also to identify adapted second line therapies.

METHODS

To overcome this difficulty, we developed multicellular tumor spheroids (MCTS) using characterized Non-Small Cell Lung Cancer (NSCLC) cell lines, monocytes from healthy donors and fibroblasts. MCTS were treated with carboplatin-paclitaxel or -gemcitabine combinations according to clinical administration schedules. The treatments impact was studied using cell viability assay, histological analyses, 3'RNA sequencing, real-time PCR, flow cytometry and confocal microscopy.

RESULTS

We showed that treatments induced a decrease in cell viability and strong modifications in the transcriptomic profile notably at the level of pathways involved in DNA damage repair and cell cycle. Interestingly, we also observed a modification of genes expression considered as hallmarks of response to immune check point inhibitors and immunogenicity, particularly an increase in CD274 gene expression, coding for PD-L1. This result was validated at the protein level and shown to be restricted to tumor cells on MCTS containing fibroblasts and macrophages. This increase was also observed in an additional cell line, expressing low basal CD274 level.

CONCLUSIONS

This study shows that MCTS are interesting models to study the impact of first line therapies using conditions close to clinical practice and also to identify more adapted second line or concomitant therapies for lung cancer treatment.

IL-7 is expressed in malignant mesothelioma and has a prognostic value

Malignant pleural mesothelioma (MPM) is an aggressive cancer mainly related to asbestos exposure. Despite recent therapeutic advances, notably immunotherapies, the benefit remains limited and restricted to a small percentage of patients. Thus, a better understanding of the disease is needed to identify new therapeutic strategies. Recently, interleukin 7 receptor (IL‐7R) has been described as being expressed by MPM cells and associated with poorer patient survival. Thus, the aim of this work was to study the IL‐7R/IL‐7 pathway in MPM using patient samples. We found that, although more than 40% of MPM cells expressed IL‐7R, IL‐7 had no effect on their intracellular signaling. Accordingly, the addition of IL‐7 to the culture medium did not affect MPM cell growth. Using The Cancer Genome Atlas (TCGA) database, we showed that high IL7 gene expression in MPM tumors was associated with a higher overall patient survival and an induction of genes involved in the immune response. In pleural effusions (PEs), we found that IL‐7 concentration was not a good diagnostic biomarker. However, we observed that high IL‐7 levels in PEs were associated with shorter survival of MPM patients, but not of lung cancer patients. The prognostic value of IL‐7 was also conserved when only patients with epithelioid mesothelioma, the most common histological type of MPM, were analyzed. Taken together, our study suggests that, although the IL‐7R/IL‐7 signaling pathway is not functional in MPM cells, IL‐7 expression in PEs may have prognostic value in MPM patients.

Evaluation of the Post-COVID-19 Functional Status (PCFS) Scale in a cohort of patients recovering from hypoxemic SARS-CoV-2 pneumonia

Introduction

COVID-19 sequelae are numerous and multisystemic, and how to evaluate those symptomatic patients is a timely issue. Klok et al proposed the Post-COVID-19 Functional Status (PCFS) Scale as an easy tool to evaluate limitations related to persistent symptoms. Our aim was to analyse PCFS Scale ability to detect functional limitations and its correlation with quality of life in a cohort of patients, 2–9 months after hospitalisation for COVID-19 hypoxemic pneumonia.

Methods

PCFS Scale was evaluated in 121 patients together with quality of life and dyspnoea questionnaires, pulmonary function tests and CT scans.

Results

We observed a high correlation with multiple questionnaires (Short Form-36, Hospital Anxiety and Depression Scale, modified Medical Research Council, end Borg Six-Minute Walk Test), making the PCFS Scale a quick and global tool to evaluate functional limitations related to various persistent symptoms following COVID-19 pneumonia.

Discussion

The PCFS Scale seems to be a suitable instrument to screen for patients who will require careful follow-up after COVID-19 hypoxemic pneumonia even in the absence of pulmonary sequelae.

A fatal case associated with Catabacter hongkongensis bacteremia in lung cancer patient: A case report

Catabacter hongkongensis is a bacterium first isolated in 2007 and has since been detected in the blood of about fifteen patients with disease such as gastrointestinal malignancy, intestinal obstruction, or acute intestinal infection. We describe herein the case of a patient newly diagnosed with metastatic lung cancer, who died from a fatal infection possibly related to Catabacter hongkongensis bacteremia. By reviewing all cases reported in the literature, our case report supports that this infection is associated with a very high mortality in cancer patients.

Involvement of the M-CSF/IL-34/CSF-1R pathway in malignant pleural mesothelioma

Background

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer related to asbestos exposure. The tumor microenvironment content, particularly the presence of macrophages, was described as crucial for the development of the disease. This work aimed at studying the involvement of the M-CSF (CSF-1)/IL-34/CSF-1R pathway in the formation of macrophages in MPM, using samples from patients.

Methods

Pleural effusions (PEs), frozen tumors, primary MPM cells and MPM cell lines used in this study belong to biocollections associated with clinical databases. Cytokine expressions were studied using real-time PCR and ELISA. The Cancer Genome Atlas database was used to confirm our results on an independent cohort. An original three-dimensional (3D) coculture model including MPM cells, monocytes from healthy donors and a tumor antigen-specific cytotoxic CD8 T cell clone was used.

Results

We observed that high interleukin (IL)-34 levels in PE were significantly associated with a shorter survival of patients. In tumors, expression of CSF1 was correlated with ‘M2-like macrophages’ markers, whereas this was not the case with IL34 expression, suggesting two distinct modes of action of these cytokines. Expression of IL34 was higher in MPM cells compared with primary mesothelial cells. Particularly, high expression of IL34 was observed in MPM cells with an alteration of CDKN2A. Finally, using 3D coculture model, we demonstrated the direct involvement of MPM cells in the formation of immunosuppressive macrophages, through activation of the colony stimulating factor-1 receptor (CSF1-R) pathway, causing the inhibition of cytotoxicity of tumor antigen-specific CD8⁺ T cells.

Conclusions

The M-CSF/IL-34/CSF-1R pathway seems strongly implicated in MPM and could constitute a therapeutic target to act on immunosuppression and to support immunotherapeutic strategies.

Brain-derived neurotrophic factor, a new soluble biomarker for malignant pleural mesothelioma involved in angiogenesis

Malignant pleural mesothelioma (MPM) is a rare and aggressive cancer related to asbestos exposure. The discovery of soluble biomarkers with diagnostic/prognostic and/or therapeutic properties would improve therapeutic care of MPM patients. Currently, soluble biomarkers described present weaknesses preventing their use in clinic. This study aimed at evaluating brain-derived neurotrophic factor (BDNF), we previously identified using transcriptomic approach, in MPM. We observed that high BDNF expression, at the mRNA level in tumors or at the protein level in pleural effusions (PE), was a specific hallmark of MPM samples. This protein presented significant but limited diagnostic properties (area under the curve (AUC) = 0.6972, p < 0.0001). Interestingly, high BDNF gene expression and PE concentration were predictive of shorter MPM patient survival (13.0 vs 8.3 months, p < 0.0001, in PE). Finally, BDNF did not affect MPM cell oncogenic properties but was implicated in PE-induced angiogenesis. In conclusion, BDNF appears to be a new interesting biomarker for MPM and could also be a new therapeutic target regarding its implication in angiogenesis.

Pleural Effusions from Patients with Mesothelioma Induce Recruitment of Monocytes and Their Differentiation into M2 Macrophages

INTRODUCTION

Mesothelioma is a rare and aggressive cancer related to asbestos exposure. We recently showed that pleural effusions (PEs) from patients with mesothelioma contain high levels of the C-C motif chemokine ligand 2 (CCL2) inflammatory chemokine. In the present work, we studied the effect of CCL2 contained in mesothelioma samples, particularly on monocyte recruitment. Then, we studied the fate of these monocytes in malignant pleural mesothelioma (MPM) PEs and their impact on tumor cells' properties.

METHODS

The implication of CCL2 in monocyte recruitment was evaluated using transmigration assays and a CCL2 blocking antibody. The phenotype of macrophages was determined by flow cytometry and enzyme-linked immunosorbent assay. Immunohistochemical analysis was used to support the results. Cocultures of macrophages with mesothelioma cells were performed to study cancer cell proliferation and resistance to treatment.

RESULTS

We showed that CCL2 is a major factor of monocyte recruitment induced by MPM samples. Macrophages obtained in MPM samples were M2 macrophages (high CD14, high CD163, and interleukin-10 secretion after activation). The colony-stimulating factor 1 receptor/macrophage colony-stimulating factor (M-CSF) pathway is implicated in M2 polarization, and high levels of M-CSF were measured in MPM samples compared with benign PE (4.17 ± 2.75 ng/mL and 1.94 ± 1.47 ng/mL, respectively). Immunohistochemical analysis confirmed the presence of M2 macrophages in pleural and peritoneal mesothelioma. Finally, we showed that M2 macrophages increased mesothelioma cell proliferation and resistance to treatment.

CONCLUSIONS

These results demonstrate the implication of CCL2 in MPM pathogenesis and designate M-CSF as a new potential biomarker of MPM. This study also identifies CCL2 and colony-stimulating factor 1 receptor/M-CSF as interesting new targets to modulate pro-tumorigenic properties of the tumor microenvironment.