Abstract: Objective To investigate the effect and molecular mechanism of microRNA-490-5p(miR-490-5p) on inflammatory response and angiogenesis in human laryngeal cancer cells inducedby hypoxia. Methods The human hypopharyngeal squamous cell carcinoma cell line FaDu was divided into 4 groups: control group (cultured in normoxic environment), hypoxic group (cultured in hypoxic environment), hypoxic + NC group (cultured in hypoxic environment and then transfected with mimics NC), and hypoxic + miR-490-5p group (cultured in hypoxic environment and then transfected with miR-490-5p mimics). The expression level of miR-490-5p in cells was detected by RT-qPCR, the cell proliferation activity was detected by CCK-8 method, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL) -1β and IL-6 in the cell supernatant were determined by ELISA, the expression levels of proteins related to the nuclear factor κB (NF-κB) pathway in cellswas detected by Western blotting, the number of HUVEC tubes formed was detected by in vitro angiogenesis assay, the expression levels of vascular endothelial growth factor ( VEGF), epidermalgrowth factor ( EGF) and hypoxia-inducible factor-1α ( HIF-1α) in cells was detected by RTqPCR and Western blotting. Results Compared with those in the control group, the relative expression level of miR-490-5p in the hypoxia group was down-regulated (P < 0. 05), the proliferative activity was increased (P< 0. 05), the levels of TNF-α, IL-1β and IL-6 in supernatant were increased ( P < 0. 05 ), the relative expression levels of phosphorylated NF-κB P65 ( p-NF-κB P65) and phosphorylated IκB kinase α (p-IκBα) were up-regulated (P < 0. 05), and the number of HUVEC tubes was increased (P< 0. 05), the mRNA and protein relative expression levels of VEGF, EGF and HIF-1α were up-regulated (P< 0. 05). Compared with those in the hypoxia + NCgroup, the relative expression level of miR-490-5p in the hypoxia + miR-490-5p group was up-regulated (P< 0. 05), the proliferation activity was decreased (P < 0. 05), and the levels of TNF-α, IL-1β and IL-6 in supernatant were decreased (P< 0. 05), the relative expression levels of p-NF-κB P65 and p-IκBα were down-regulated, while the number of HUVEC tube formation was decreased (P< 0. 05 ), and the mRNA and protein expression levels of VEGF, EGF and HIF-1α were also down-regulated (P< 0. 05). Conclusion  Under hypoxic conditions, overexpression of miR-490-5p can inhibit the inflammatory response of laryngeal cancer cells and reduce the formation
of tumor blood vessels.

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