The effect of metastatic gastric cancer-secreted exosomes on proliferative and migratory characteristics of HUVEC endothelial cell line

Abstract

Gastric cancer is the fifth most common cancer and the third deadliest cancer in the world. In Iran, gastric cancer is the most common cancer in men and the third in women. Unlike developed countries, the incidence of this cancer in Iran is increasing so that it is a problem in the north and northwest. Exosomes are homogeneous membrane vesicles 40 to 150 nm in diameter that are derived from the exocytosis of intracellular vesicles and are released into the extracellular space when they fuse with the cell membrane. Tumor-derived exosomes are either released locally or enter the bloodstream to interact with their target cells, which can be immune cells.

Methods: The MKN-45 cell line is cultured in RPMI-1640 medium and secreted exosomes are extracted. HUVEC cells are also cultured as endothelial cell models and exposed to purified exosomes from the MKN-45 cell line. RNA of cells was extracted and after cDNA synthesis, using quantitative real-time PCR, mRNA and miRNAs controlling the expression of genes associated with migration and proliferation (mir-152, mir-16 and mir-443 and the VEGF and HIF-1α genes) will be checked. MTT test is also used to check cell proliferation. The effect of exosomes on migratory characteristics is also determined by the wound healing or scratch test.

Results: Exposure of HUVEC cells to purified exosomes from the MKN-45 cell line caused changes in the expression of genes involved in the migration and proliferation of these cells. Based on the results of the study, the expression of mir-152, mir-16 and mir-443 in cells treated with the exosomes was significantly reduced compared to untreated cells and the expression of the target gene (VEGF and HIF-1α) in treated cells was increased significantly in cells treated with the exosomes compared to untreated cells. The results of MTT test also showed an increase in proliferation of cells treated with these exosomes.