Tigecycline inhibits glioma growth by regulating microRNA-199b-5p-HES1-AKT pathway.

Tigecycline is a broad-spectrum, first-in-class glycylcycline antibiotic currently used to treat complicated skin infections and community-acquired pneumonia. However, there is accumulating evidence showing that tigecycline has anticancer properties. In this study, we found tigecycline could inhibit cell proliferation by inducing cell-cycle arrest, but not apoptosis in glioma. To find the underlying mechanism of how tigecycline inhibits cell proliferation, the expression of miRNAs, which were related to regulating cell-cycle progression, was detected with miRNA assay. We found that miR-199b-5p expression was significantly increased after tigecycline treatment, and miR-199b-5p target gene HES1 was downregulated. In addition, the PI3K/AKT pathway was inhibited and p21 expression was increased. When treated with tigecycline and miR-199b-5p antagomir simultaneously in glioma cells, we found that miR-199b-5p antagomir could partly block the effects induced by tigecycline. Tigecycline effectively upregulated miR-199b-5p expression and inhibited tumor growth in the xenograft tumor model of U87 glioma cells. These results suggest that tigecycline may induce cell-cycle arrest and inhibit glioma growth by regulating miRNA-199b-5p-HES1-AKT pathway. Thus, tigecycline is a promising agent in the treatment of malignant gliomas. (C) 2016 AACR.