Esophageal cancer is one of the most common malignant tumors of the digestive tract, and miR-224 can promote the hypoxia tolerance of esophageal cancer cells. The expression of miR-224 and HIF-1α in esophageal cancer cells under hypoxic induction and their relationship with ROS was studied using RT-qPCR and Western Blot assays
cell viability and apoptosis under hypoxia, as well as the effects of miR-224 on cell proliferation and drug resistance, were investigated using CCK8, Annexin V-FITC/PI, H2DCFDA staining and Western Blot assays. Under hypoxic induction, miR-224 and HIF-1α expressions were upregulated, with the upregulation of miR-224 being related to ROS accumulation, while HIF-1α upregulation was not affected by ROS. Furthermore, the upregulation of miR-224 facilitated the survival of esophageal cancer cells under hypoxic conditions and reduced their chemosensitivity to CDDP. This effect was also validated in vitro, as miR-224 overexpression promoted the malignant behaviors in ESCC cells. Under hypoxic induction, ROS accumulation can lead to the upregulation of miR-224. MiR-224 facilitates the survival of esophageal cancer cells under hypoxic conditions and induces chemotherapeutic drug resistance.