78 Background: Aurora kinase A gene (AURKA) is frequently amplified and/or overexpressed in several malignancies. Inflammation contributes to the pathogenesis of gastric tumorigenesis. We explored the roles of AURKA in inflammation and tumorigenesis. Methods: Immunofluorescence, immunohistochemistry, Quantitative real-time PCR, immunoblot, co-immunoprecipitation, luciferase reporter, and in vitro kinase assays were used to analyze AGS and MKN28 gastric cancer cells. We also analyzed Tff1–/– mice, growth of tumor xenografts, and human tissues. Results: We showed an elevated level of AURKA in the Tff1–/– gastric tissues as compared to wild-type. We also found a positive correlation between AURKA and inflammation (coefficient r = 0.25; P = 0.0056) as well as TNF-α (coefficient r = 0.25; P = 0.0057). AURKA inhibition by MLN8237, a specific AURKA inhibitor, reduced nuclear staining of NFκB in human gastric cancer samples and mouse epithelial cells, suppressed NFκB reporter activity, and reduced the expression of NFκB target genes that regulate inflammation and cell survival. Additionally, AURKA inhibition reduced xenograft tumor size in mice and reversed the development of gastric tumors in Tff1–/– mice. Further, we found that AURKA regulate NFκB activity by directly binding and phosphorylating IκBα in vitro. Premalignant and malignant lesions from the gastric mucuosa of patients had increased levels of AURKA protein and nuclear NFκB, compared with healthy gastric tissue. Conclusions: In analyses of gastric cancer cell lines, human tissue samples, and mouse models, we found AURKA to be upregulated during chronic inflammation to promote IκBα-mediated activation of NFκB and tumorigenesis. This provides a novel role of AURKA in cancer and shows the importance of targeting it as a therapeutic approach in cancer treatment.
Aurora kinase A regulates Survivin stability through targeting FBXL7 in gastric cancer drug resistance and prognosis