2-Hydroxy-3-methylanthraquinone inhibits lung carcinoma cells through modulation of IL-6-induced JAK2/STAT3 pathway

Background: 2-hydroxy-3-methylanthraquinone (HMA), an anthraquinone monomer in traditional Chinese medicine Hedyotis diffusa, has been reported to inhibit the growth of several types of cancer, but its effect on lung cancer has not been adequately investigated. Hypothesis/Purpose: This study aimed to test the hypothesis that HMA inhibit the growth, migration, and invasion of lung cancer cells in part via downregulation of interleukin (IL)-6-induced JAK2/STAT3 pathway. Methods: Growth and apoptosis of lung cancer cells were quantitated by CCK-8 assay and Annexin V-FITC/PI flow cytometric analysis, respectively. Migration and invasion of A549 cells were determined by wound-healing assay and transwell invasion assay, respectively. The effect of HMA on cytokines expression in A549 cells was evaluated by the cytokine antibody array assay. Gene expression and protein levels of related molecular markers were quantitated by real time-PCR and Western blot analysis, respectively. Results: HMA significantly inhibited IL-6-stimulated growth and colony formation of A549 cells, increased the number of apoptotic cells, and inhibited invasion associated with downregulation of expression of IL-6-induced MMP-1, MMP-2, and MMP-9 genes. IL-6 increased the levels of tyrosine phosphorylation of JAK2 and STAT3 in A549 cells, which was reversed by HMA treatment. In addition, HMA reduced the expression of a series of inflammation-related cytokines in A549 cells supernatant, including IL-6, G-CSF, IL-6R, IL-8, MCP-1, RANTES, TNF-alpha. Conclusion: These results suggest that HMA may inhibit the growth and invasion of lung cancer cells in part via downregulation of IL-6-induced JAK2/STAT3 pathway.