miR-599 and miR-185 down-regulate periostin expression in human lung cancer cells

Background: Prognosis of lung cancer remains poor. The over-expression of periostin, osteoblast-specific factor, was reported in cancers such as ovarian and breast cancers. However, it is unclear about effects of periostin on the invasion of human lung cancer, and whether the mRNA and protein expression of periostin was regulated by miRNA needs to be explored. Therefore, we explored effects of periostin on the invasion of human lung cancer cells, and how periostin expression was regulated by miRNA. Methods: Human lung cancer cell line A549 cells were treated with different concentrations of periostin protein, and tumor invasion was detected by Transwell assay. A549 and another lung cancer cell line BEAS-2B cells were transfected with mixture of Dicer-siRNA-152 and Drosha-siRNA- 1200, or negative control (NC) siRNA. mRNA expression of periostin were detected by qPCR. Protein expression of periostin were examined by Western Blot. HEK293A cells were transfected with vectors (pMIR/report-3'POSTN and pRL-TK), and miRNA (miR-543, miR-296-3P, miR-599, miR-185, miR-202-3P, and NC miRNA, respectively). In addition, HEK293A cells were transfected with periostin gene mutated at binding sites of miR-599 or miR-185. Expression of periostin was determined by measuring relative light unit in dual-luciferase reporter assay. Results: Periostin protein altered invasion of A549 cells in a dose-dependent manner. mRNA expression of periostin in A549 and BEAS-2B cells increased significantly after miRNA was interrupted. Protein expression of periostin in BEAS-2B cells increased markedly after miRNA was interrupted. Expression of periostin was lowest when HEK293A cells were transfected with miR-599 and miR-185. Expression of periostin was not altered by miR-599 or miR-185 mimics when HEK293A cells were transfected with periostin gene mutated at binding sites of miR-599 or miR-185. Conclusions: Periostin protein alters invasion of human lung cancer cells. miR-599 and miR-185 down-regulate periostin expression in lung cancer cells.