Curcumin inhibits esophageal squamous cell carcinoma progression through down-regulating the circNRIP1/miR-532-3p/AKT pathway.

Curcumin shows an anti-cancer role in many kinds of tumors. However, the mechanism of its anti-tumor function in esophageal squamous cell carcinoma (ESCC) remains largely unknown. Herein, we explored the therapeutic potential of curcumin for esophageal cancer. Curcumin could time- and dose-dependently inhibit ESCC cells activity. Additionally, ESCC cells exposed to 20 µM of curcumin exhibited significantly decreased proliferative and invasive capacities, as well as enhanced cell apoptosis. ESCC tissues and cells exhibited significantly increased circNRIP1 expression when compared to their counterparts. circNRIP1 knockdown markedly impaired cell proliferation, clone formation, cell migration and invasion but promoted apoptosis. Exposure to 10-20 µM of curcumin inhibited circNRIP1 expression, however, overexpression of circNRIP1 could significantly restored the biological characteristics that were inhibited by curcumin exposure in vivo and in vitro. circNRIP1 promoted the malignancy of ESCC by combining miR-532-3p, and downstream AKT3. Curcumin inhibited AKT phosphorylation by up-regulating miR-532-3p expression, thereby inhibiting the activation of the AKT pathway. In summary, curcumin is a potent inhibitor of ESCC growth, which can be achieved through the regulation of the circNRIP1/miR-532-3p/AKT pathway. This research may provide new mechanisms for curcumin to inhibit the malignant development of ESCC.