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Álvaro González



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    MA04 - Models and Biomarkers (ID 122)

    • Event: WCLC 2019
    • Type: Mini Oral Session
    • Track: Biology
    • Presentations: 1
    • Now Available
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      MA04.09 - Study of Exosomes in NSCLC for Biomarkers Searching (Now Available) (ID 2417)

      13:30 - 15:00  |  Author(s): Álvaro González

      • Abstract
      • Presentation
      • Slides

      Background

      Exosomes are small membranous vesicles secreted by a most type of cells (especially in tumoral processes), around 40-130 nm of size, that carry relevant information to distant tissues and being able to modulate its physiology. Exosomes have been detected in different clinical samples and may play a key role in NSCLC, participating in several processes such as horizontal transfer of RNA from tumor to microenvironmental cells, angiogenesis, pre-metastatic niche formation, immunosuppression; and could also be key elements in stem cell differentiation (from different origins).

      The principal objective of this study was to analyze the exosomes cargo from NSCLC cell lines and primary cultures with diverse characteristics under different growth conditions: suspension cultures with cancer stem cells (CSCs) features and monolayer cultures.

      Method

      Primary cultures from resected NSCLC patients and NSCLC cell lines were successfully established. Differentiated tumor cells were cultured under adherent conditions (2D) whereas CSCs were established in suspension cultures (3D tumorspheres). Exosomes isolation was performed by ultracentrifugation. Exosomes characterization was carried out through nanovesicles tracking analysis (NTA) and electron microscopy; and the determination of surface markers through immunoblot and flow cytometry. Exosomal DNA was extracted in order to determine the mutational status of the EGFR and RAS genes by BEAMing Digital PCR (Sysmex). Transcriptomic analysis has been carried out from exosomal RNA through whole genome gene expression microarrays, (Affymetrix). The data was normalized by Robust Multi-Array Average (RMA) and analyzed using Transcriptome Analysis Console (TAC), MultiExperiment Viewer (MeV) software and Partek Genomics Suite. Statistical significance was established at (p ≤ 0.01).

      Result

      In reference to the characterization, NTA and electron microscopy showed that exosomes were obtained free of cellular debris and their size ranges from 108-125 nm, according to the size of tumor-derived microvesicles. Exosomal surface markers analyzed by immunoblot and flow cytometry were detected in samples, confirming proper isolation. Mutational analysis of EGFR and RAS genes performed on exosomal DNA shown the same pattern displayed by the origin cells. Transcriptomic analysis of the exosomal content showed that the expression of mRNAs, miRNAs and precursors were significantly different between 3D and 2D-derived exosomes. Finally, a pathway enrichment analysis was carried out to know in which biological processes (cancer-related) are involved.

      Significant differential expressions were also found between mRNAs, miRNAs and pre-miRs present in exosomes from adenocarcinoma (ADC) vs. squamous cell carcinoma (SCC). Interestingly, 7 miRNAs differentially expressed in exosomes (miR-200c; miR-29a; miR-339; miR-224; miR-31; miR-21; miR-33a) had already been identified as overexpressed in tumor tissue from NSCLC patients by our group. Moreover, miR-339 y miR-21 were related to prognosis (p < 0.05) in ADC group.

      Conclusion

      Differences in exosomal mRNA, miRNAs and pre-miRs expression have been observed between: i) lung-tumorspheres vs. more differentiated tumor cells and ii) ADC vs. SCC cultures. In addition, the same mutational pattern was detected in exosomes as compared with their parental cultures. Therefore, exosomes can be a useful source for biomarkers analysis in NSCLC.

      Supported by grant GV/2018/026, PI18/00266, & Asociación Española Contra el Cáncer (AECC Valencia).

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    P2.03 - Biology (ID 162)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Biology
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
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      P2.03-08 - Analysis of Immunosuppressive Factors Produced by CSCs Revealed Galectin-3 as Immune Modulator with Prognostic Value in NSCLC Adenocarcinoma (ID 1855)

      10:15 - 18:15  |  Author(s): Álvaro González

      • Abstract

      Background

      The study of the tumor microenvironment is leading to a better understanding of the tumor escape from immunosurveillance and immunotherapy response. Cancer stem cells (CSCs) are targets poorly recognized by the immune surveillance system given that they favor an immunosuppressive microenvironment. The aim of this work is to study the interactions between CSCs and the immune microenvironment in NSCLC.

      Method

      Tumor cells from 8 resected NSCLC patients and 12 cell lines were cultured using a sphere forming assay for CSCs enrichment. Adherent cultures were established as differentiated controls. The gene expression of IL-4, IL-10, IL6, IL8 LGALS-3 was analyzed by RTqPCR. Gene expression results were validated at a protein level by a sensitivity bead-based multiplex immunoassay using the Millipore kit for Luminex 100/200. The prognostic value of these factors in silico was determined in a cohort of 661 patients from The Cancer Genome Atlas (TCGA) cohort. Prognostic value was assessed by Cox regression and Kaplan‐Meier curves ﴾long rank‐test﴿, considering significant when p<0.05.

      Result

      Patients’ median age was 67 years [57-74], 62% were male, and 62.5% were adenocarcinomas (ADC). Gene expression analysis revealed that lungspheres had significantly higher expression of LGALS3 compared to differentiated adherent cells. On the contrary, adherent cells had significantly higher expression of IL6. In concordance with gene expression levels, we observed significant differences in the secretion of these two soluble factors (IL-6 and Galectin-3) between adherent cells and tumorspheres. Neither expression nor secretion levels of IL-10 and IL-4 were detectable. We had not observed significant results for IL-8. Survival analysis showed that ADC patients with higher LGALS3 expression had significantly decreased overall survival (OS, 40.49 vs. 87.90 months, p= 0.005) and relapse-free survival (25.28 vs. 41.25 months, p=0.003) than the group with LGALS3 expression below the median. The multivariate analysis showed that LGALS3 expression can be established as an independent prognostic biomarker for OS [HR=1.75; 95% CI, 1.19-2.59; p=0.004] and for PFS in lung adenocarcinoma [HR=1.68; 95% CI, 1.22-2.32; p= 0.001].

      Conclusion

      Our results suggest that Galectin-3 highly secreted by lung CSCs can be involved in the modulation of the immune microenvironment. Moreover, Galectin-3 is an independent prognostic biomarker for overall survival and relapse-free survival in lung adenocarcinomas.

      Supported by grants CB16/12/00350, PI18/00266 and PI15-00753 from ISCIII and ACIF/2018/275 from GVA and FSE