1282P - Characterization of cancer stem cell and immune microenvironment interactions in non-small cell lung cancer (NSCLC)

Abstract

Background: Lung cancer stem cells (CSCs) are a small subpopulation of cells with self-renewal, tumorigenic properties and the ability to grow forming tumourspheres in non-adherent conditions. CSCs in non-small cell lung cancer (NSCLC) are targets poorly recognized by the immune surveillance system given that they favour an immunosuppressive microenvironment. The aim of this work was to compare the release of cytokine between monolayer cells and tumourspheres. Methods: The study was performed on medium supernatant of cells from two NSCLC tumour patients (patient 1 and patient 2) samples and ten cell lines (A549, H1650, H460, H23, H358, H2228, HCC827, PC9, H1993, and SW900) grown in monolayer and tumourspheres at 3 different densities (104, 5·105 and 105 cells/ml). We analysed four soluble factors with immunosuppressive (IL-4, IL-10), and immunoregulatory (IL-6, IL-8) capacity through sensitivity bead-based multiplex assay using the Millipore kit and the Luminex 100/200. Results: All human tumour cell lines and primary cells secreted detectable levels of IL-6 and IL-8. In contrast, IL-10 and IL-4 levels were below detectable range (<1.83 and <1.46 pg/ml, respectively) for most of these cell lines and NSCLC tumour samples. We have observed differences between levels of IL-6 and IL-8 secreted by adherent cells and tumourspheres and differences between samples (Table).Table: 1282PDifferences in the secretion of IL-6 and IL-8 in adherent cells and tumourspheres by multiplex analysis. Detection range of IL-6 (0.17-1750.12 pg/ml). Detection range of IL-8(0.28-2273.3 pg/ml)Samplespg/ml x 105 cells IL-6pg/ml x ·105 cells IL-8Adherent cellsTumourspheresAdherent cellsTumourspheresA549<0.171.3130.1158.2H22281750,11>1750.12>2273.3172.80HCC827348.2>1750.122177.4>2273.3H35810.927.81774.8>2273.3H199334.42.2658.2479.3PC9144.45.4597.2321.9SW900121.75.41006225.2H460359.8227.81298.82201.3H233.72.8407.81290.8H1650995.9352.230.250.3Patient 117.40.6>2273.330.0Patient 2>1750.12>1750.12>2273.3>2273.3 Open table in a new tab Conclusions: Our preliminary results suggest that cells grown in adherence show increased levels of IL-6 compared to lung-tumourspheres. The next step is the expansion of the cohort to obtain significant results. Supported by grants from FEDER and PI12-02838 and PI15-00753 from ISCIII. Legal entity responsible for the study: Fundación para la Investigación del Hospital General Universitario de Valencia Funding: Supported by grants from FEDER and PI12-02838 and PI15-00753 from ISCIII. Disclosure: All authors have declared no conflicts of interest. Keywords: IL, cancer stem cells, Non-small cell lung cancer, Immune microenvironment