<p>Hypoxic Non-Small-Cell Lung Cancer Cell-Secreted Exosomal microRNA-582-3p Drives Cancer Cell Malignant Phenotypes by Targeting Secreted Frizzled-Related Protein 1</p>

Abstract

Background: Hypoxic environment and exosomes (exos)-mediated intercellular communication are crucial for cancer invasion and metastasis, but the mechanisms are not yet fully understood. In this study, we investigated the regulatory effect of hypoxic tumor cell-secreted exosomal miR-582-3p on non-small-cell lung cancer (NSCLC) cell malignant phenotypes. Methods: The concentration and diameters of exos were evaluated by nanosight particle tracking analysis. microRNA-582-3p (miR-582-3p) expression was detected by quantitative real-time PCR. The fluorescent dye PKH26 was used to label exos. The direct interaction between miR-582-3p and secreted frizzled-related protein 1 (SFRP1) was determined by dual-luciferase activity assay. NSCLC cell proliferation, migration, and invasion abilities were assessed by cell count kit-8 assay, wound healing assay, and transwell migration and invasion assay. Western blot analysis was performed to detect the protein expression level. Results: Hypoxic NSCLC cell-derived exos promoted the proliferation, migration, and invasion of normoxic NSCLC cells. miR-582-3p expression was upregulated in hypoxic NSCLC cells and hypoxic NSCLC cell-secreted exos. Hypoxic NSCLC cell-derived exos transmitted miR-582-3p to normoxic NSCLC cells. Hypoxic NSCLC cell-secreted exosomal miR-582-3p promoted the proliferation, migration, and invasion of normoxic NSCLC cells. miR-582-3p inhibited the expression of SFRP1 protein by binding to its 3ʹ-UTR. In addition, enforced expression of SFRP1 restrained malignant phenotypes of normoxic NSCLC cells, which was abrogated by hypoxic NSCLC cell-secreted exosomal miR-582-3p. Conclusion: Hypoxic NSCLC cell-secreted exosomal miR-582-3p drives cancer cell malignant phenotypes by targeting SFRP1, which provides a better understanding of cancer metastasis and may facilitate the development of therapeutics against human NSCLC.

Alternatively Expressed Transcripts Analysis of Non-Small Cell Lung Cancer Cells under Different Hypoxic Microenvironment

“…Physiologically appropriate functioning of cellular process depends on adequate oxygen and energy supply [21]. Hypoxia has been reported to promote metastasis and invasion of NSCLC [22][23][24]. In this study, we found that hypoxia significantly increased the migration and invasion ability of NSCLC cells.…”

Hypoxia Induced Changes of Exosome Cargo and Subsequent Biological Effects

“…MiR-31-5p and miR-582-3p were largely internalized within hypoxic exosomes. Exosomal transfer of miRNAs from hypoxic cancer cells to normoxic cancer cells significantly enhanced the proliferation, migration, and invasion of receptive normoxic lung cancer cells in vitro , and promoted lung adenocarcinoma metastasis ( 77 , 83 ). Similarly, hypoxia induced the upregulation of angiopoietin-like 4 (ANGPTL4), HIF-1α/COX-2 and miR-135b and miR-210 in the exosome cargo of A549 cells, exosome transfer of these factors to other A549 cells led to the enhanced proliferation, migration, angiogenesis, and tumor progression ( 80 , 84 ).…”

Characterization of the MicroRNA Cargo of Extracellular Vesicles Isolated from a Pulmonary Tumor-Draining Vein Identifies miR-203a-3p as a Relapse Biomarker for Resected Non-Small Cell Lung Cancer

“…MiR-574-5p has been previously observed that it was upregulated in lung cancer patients vs. controls and that it decreases their expression in PB after surgical resection of the tumor [50]. miR-582-3p has been described as upregulated in hypoxic conditions and is secreted in EVs to promote tumorigenesis [51], and EV-miR-224-5p has been shown to promote tumorigenesis in NSCLC [52]. However, some of these results have been only observed in cell lines, and regardless, their expression has been analyzed in TDV.…”