Abstract: Li Xiaojing, Li Zhifeng, Li Xianping, Liu Baoguo, Liu Zhijun Department of Dermatology, Affiliated Hospital of Hebei University of Engineering, Handan 056002, Hebei, China Corresponding authors: Liu Baoguo, Email: LBG66@163.com; Liu Zhijun, Email: zlmdsh@126.com 【Abstract】 Objective To evaluate effects of tanshinone ⅡA on the invasion and migration of melanoma A375 cells, as well as on the mRNA and protein of CXC chemokine receptor type 7 （CXCR7）. Methods In vitro cultured A375 cells were divided into 4 groups to be treated with tanshinone ⅡA at different concentrations of 1, 2 and 4 mg/L, and 0.1% dimethyl sulfoxide （DMSO） （control group） for 48 hours, respectively. Wound scratch assay and Transwell invasion assay were conducted to estimate the migratory and invasive abilities of A375 cells, respectively, and real-time fluorescence-based quantitative PCR （qRT-PCR） and Western blot analysis to determine the mRNA and protein of CXCR7 in A375 cells, respectively. Results After 48-hour treatment, the 1-, 2- and 4-mg/L tanshinone ⅡA groups showed significantly decreased number of A375 cells crossing the polycarbonate membrane per high-power field （× 200） （71.00 ± 4.00, 51.00 ± 2.00 and 37.00 ± 3.61, respectively） in Transwell invasion assay, as well as decreased number of A375 cells migrating to the scratch zone （301 ± 3.00, 253.00 ± 3.61 and 126.00 ± 7.00, respectively） in wound scratch assay, compared with the control group （105.33 ± 6.51, 332.00 ± 6.24, respectively, all P < 0.05）. Additionally, qRT-PCR and Western blot analysis revealed that the mRNA and protein of CXCR7 was significantly lower in the 1-, 2- and 4-mg/L tanshinone ⅡA groups than in the control groups （CXCR7 mRNA: 0.63 ± 0.04, 0.44 ± 0.02 and 0.31 ± 0.01 vs. 1.00 ± 0.02; CXCR7 protein: 0.573 ± 0.015, 0.416 ± 0.011 and 0.260 ± 0.055 vs. 0.9000 ± 0.010; all P < 0.05）. Moreover, inhibitory effects of tanshinone ⅡA on the migration and invasion of A375 cells, as well as on the mRNA and protein of CXCR7, were significantly enhanced with the increase of tanshinone ⅡA concentrations （all P < 0.05）. Conclusion Tanshinone ⅡA can inhibit the migratory and invasive abilities of melanoma A375 cells by down-regulating CXCR7 .