BACKGROUND AND OBJECTIVECurcumin, a natural compound, is derived from the rthizom of Curcuma longa. In vitro and in vivo preclinical studies have shown its anti-inflammatory, antioxidant, anticancer activities and so on. miR-186*, which was found by microarray technology, was highly expressed in lung carcinoma cells A549/DDP. The aim of this study is to illustrate whether Curcumin could promote the apoptosis of A549/DDP cells through regulating the expression of miR-186*.

METHODSAn oligonucleotide microarray chip was used to profile microRNA (miRNA) expressions in A549/DDP cells treated with and without Curcumin. The significantly differentially expressed miRNA, which was selected from microarray chip, validated by quantitative real-time PCR. Ultimately, the remarkably expressed miRNA modulated the apoptosis assaying by flow cytometry expriments and the survival rate was measured by MTT method.

RESULTSThe microarray chip results demonstrated: Curcumin altered the expression level of miRNAs compared with untreated control in A549/DDP cell line, miR-186* was significantly down-regulated after Curcumin treatment, which confirmed by quantitative real-time PCR. Down-regulation of miR-186* expression by curcumin elevated the apoptosis, and the survival rate of A549/DDP cells decreased; but up-regulation of miR-186* expression by transfection its mimics restrained the apoptosis, the survival rate of A549/DDP cells increased, which were assayed by flow cytometry expriments and MTT method.

CONCLUSIONModulation of miRNAs expression may be an important mechanism underlying the biological roles of Curcumin.