Effects of hypoxic exosomes on the proliferation, migration and invasion of hepatocellular carcinoma Huh7 cells

Abstract

Objective: To explore the effects of hypoxic exosomes secreted from hepatocellular carcinoma Huh7 cells on the proliferation, migration and invasion under co-cultured normoxic condition. Methods: Hypoxic exosomes secreted from Huh7 cells under hypoxic conditions were extracted by differential ultracentrifugation. Transmission electron microscopy, nanoparticles tracking analysis and western blot were used for the identification of hypoxic exosomes. Hypoxic exosomes were co-cultured with Huh7 cells under normoxic conditions. CCK8, cell scratch and transwell assay were used to detect the changes of cell proliferation, migration and invasion. Statistical analysis was performed by one-way ANOVA and t-test. Results: Hypoxic exosomes secreted from Huh7 cells ranged in size from 30 to 150 nm in diameter, and expressed exosome surface markers CD9, CD63 and TSG101. Hypoxic exosomes significantly enhanced the proliferation of normoxic Huh7 cells (A value of hypoxic exosomes and control group at 48 and 72 h were 2.131 ± 0.092 and 1.760 ± 0.104,t= 3.740,P<0.01, 3.121 ± 0.157 and 2.298 ± 0.085,t= 8.289,P< 0.01). The migration distance between hypoxic exosome and control group at 48 and 72 h were (0.37 ± 0.06 cm)and(0.19 ± 0.05 cm),t= 4.813,P< 0.05, (1.15 ± 0.07 cm) and(0.62 ± 0.08 cm),t= 8.874,P< 0.05, and invasion ability [hypoxic exosomes and control group were (123 ± 18), (44 ± 12),t= 6.203,P< 0.01]. Conclusion: Hypoxic exosomes secreted from hepatocellular carcinoma Huh7 cells can promote cell proliferation, migration and invasion in hypoxic environment, suggesting that intercellular information transmission mediated by hypoxic exosomes may be one of the key mechanisms for the amplification of malignancy of hepatocellular carcinoma cells in hypoxic microenvironment.