目的:研究全反式维A酸（ATRA）对人恶性黑素瘤A375细胞中上皮-间质转化（EMT）相关分子表达的影响。方法:用含10 μmol/L ATRA的DMEM培养基和DMEM培养基分别处理A375细胞24和48 h作为ATRA-1组和ATRA-2组、对照1组和对照2组，采用实时定量PCR法检测EMT相关基因上皮钙黏着蛋白、神经钙黏着蛋白、波形蛋白、β联蛋白mRNA的表达。Western印迹法检测ATRA-1组、ATRA-2组、对照1组中上述蛋白的相对表达量，直接免疫荧光法检测上皮钙黏着蛋白和波形蛋白的荧光强度。统计分析采用两因素方差分析、单因素方差分析及LSD-n t检验。n 结果:ATRA-1组和ATRA-2组分别与对照1组和对照2组相比，上皮钙黏着蛋白mRNA的表达均显著增加（n F = 13.148、31.529，n P < 0.05），而神经钙黏着蛋白、波形蛋白、β联蛋白mRNA的表达均显著降低（均 n P < 0.05）；ATRA-2组上皮钙黏着蛋白mRNA的表达显著高于ATRA-1组（ n F = 13.148，n P < 0.05），而其他3种蛋白mRNA的表达显著低于ATRA-1组（均 n P 0.05）。Western印迹法显示，与对照1组相比，ATRA-1组和ATRA-2组上皮钙黏着蛋白表达上调，而神经钙黏着蛋白、波形蛋白、β联蛋白表达均下调（均 n P < 0.05）；与ATRA-1组相比，ATRA-2组上皮钙黏着蛋白表达上调（ n P < 0.05），神经钙黏着蛋白、波形蛋白、β联蛋白表达下调（均 n P < 0.05）。直接免疫荧光显示，ATRA-1组、ATRA-2组上皮钙黏着蛋白的荧光强度（6.23 ± 0.08、10.37 ± 0.13）显著高于对照1组（2.37 ± 0.14，均 n P < 0.05），而波形蛋白的荧光强度（15.17 ± 0.18、10.29 ± 0.03）显著低于对照1组（50.16 ± 0.26，均 n P < 0.05），抑制上皮向间质转化。n 结论:ATRA可上调A375细胞中上皮钙黏着蛋白的表达，降低神经钙黏着蛋白、波形蛋白、β联蛋白的表达，可能抑制A375细胞发生EMT现象。“,”Objective:To evaluate the effect of all-trans retinoic acid (ATRA) on the expression of epithelial-mesenchymal transition (EMT) -related molecules in human malignant melanoma A375 cells.Methods:Cultured A375 cells were divided into 4 groups: control-1 and -2 groups treated with Dulbecco′s modified Eagle medium (DMEM) for 24 and 48 hours respectively, and ATRA-1 and ATRA-2 groups treated with DMEM containing 10 μmol/L ATRA for 24 and 48 hours respectively. After the treatment, real-time quantitative PCR was performed to determine the mRNA expression of EMT-related genes E-cadherin, N-cadherin, vimentin and β-catenin in the above 4 groups, Western blot analysis to determine the relative expression of the above proteins, and direct immunofluorescence study to assess the fluorescence intensity of E-cadherin and vimentin in the ATRA-1, ATRA-2 and control-1 groups. Statistical analysis was carried out by using two-way analysis of variance, one-way analysis of variance and least significant difference- n t test.n Results:Real-time quantitative PCR showed that the E-cadherin mRNA expression was significantly higher in the ATRA-1 group than in the control -1 group (n F = 13.148, n P < 0.05) , and higher in the ATRA-2 group than in the control-2 group ( n F = 31.529, n P < 0.05) ; the mRNA expression of N-cadherin, vimentin and β-catenin was significantly lower in the ATRA-1 group than in the control-1 group ( n P < 0.05) , and lower in the ATRA-2 group than in the control-2 group ( n P < 0.05) ; the ATRA-2 group showed significantly increased mRNA expression of E-cadherin ( n F = 13.148, n P < 0.05) , but significantly decreased mRNA expression of the other 3 proteins compared with the ATRA-1 group (all n P 0.05) . Western blot analysis showed that the protein expression of E-cadherin significantly increased, but the protein expression of N-cadherin, vimentin and β-catenin significantly decreased in the ATRA-1 and ATRA-2 groups compared with the control-1 group (all n P < 0.05) ; compared with the ATRA-1 group, the ATRA-2 group showed significantly increased protein expression of E-cadherin ( n P < 0.05) , but significantly decreased protein expression of N-cadherin, vimentin and β-catenin (all n P < 0.05) . Direct immunofluorescence study showed that the fluorescence intensity of E-cadherin was significantly higher in the ATRA-1 group and ATRA-2 group (6.23 ± 0.08, 10.37 ± 0.13, respectively) than in the control-1 group (2.37 ± 0.14, both n P < 0.05) , while the fluorescence intensity of vimentin was significantly lower in the ATRA-1 group and ATRA-2 group (15.17 ± 0.18, 10.29 ± 0.03, respectively) than in the control-1 group (50.16 ± 0.26, both n P < 0.05) , and the cells in the ATRA-1 group and ATRA-2 group transformed from spindle- to cobble-stone-like in shape.n Conclusion:ATRA can up-regulate the expression of E-cadherin, down-regulate the expression of N-cadherin, vimentin and β-catenin in A375 cells, and may inhibit the EMT of A375 cells.