目的：阐明组蛋白去乙酰化酶(HDAC)抑制剂辛二酰苯胺异羟肟酸(SAHA)对脉络膜黑色素瘤(CM)细胞系C918细胞增殖的影响并探讨相关机制。

方法：使用倒置荧光显微镜观察不同浓度SAHA(0.625、1.25、2.5μmol/L)对C918细胞形态的影响； CCK-8法观察C918细胞活力的变化； 细胞平板克隆形成实验和EdU染色法观察SAHA对C918细胞增殖的影响； 同时，Western blot检测细胞增殖相关蛋白c-Myc、细胞周期蛋白CyclinA2和CDK2以及HDAC7和成纤维细胞生长因子18(FGF18)的表达。

结果：与空白对照组比较，光镜下见SAHA可减小C918的细胞密度，促进细胞皱缩，且随着SAHA浓度的增加对细胞的抑制作用也增强； CCK-8法检测结果显示SAHA浓度依赖性抑制C918细胞活力，2.5μmol/L浓度时抑制率达80%； Western blot结果表明SAHA可呈浓度依赖地降低C918细胞中的增殖蛋白c-Myc、细胞周期蛋白CyclinA2和CDK2的表达； 另外，1.25μmol/L SAHA显著降低EdU染色阳性细胞数和细胞克隆数。更为重要的是，与空白对照组相比，SAHA能浓度依赖地降低HDAC7和FGF18的表达。

结论：SAHA能够通过抑制HDAC7/FGF18信号通路抑制CM细胞系C918细胞的增殖。

METHODS: Inverted fluorescence microscope was used to observe the effect of different concentrations of SAHA(0.625, 1.25 or 2.5 μmol/L)on the morphology of C918 cell. The cell viability was detected by cholecystokinin octapeptide(CCK-8)assay. Plate clone formation assay and EdU staining were carried out to measure the effect of SAHA on the cell proliferation. Meanwhile, the expressions of cell proliferation-related proteins including c-Myc, CyclinA2 and CDK2, and histone deacetylase 7(HDAC7)and fibroblast growth factor 18(FGF18)were detected by Western blot.

RESULTS: Compared with the control group, the cell density was reduced in SAHA. SAHA could also promote cell shrinkage, and the inhibition on cell was in a concentration-dependent manner. CCK-8 assay showed that SAHA treatment decreased cell viability in a dose-dependent manner and the inhibition rate was 80% when SAHA at 2.5 μmol/L. Compared with the control group, Western blot showed that SAHA could suppress the expression of cell proliferation proteins including c-Myc, CyclinA2 and CDK2 in a dose-dependent manner. In addition, 1.25 μmol/L SAHA significantly decreased the numbers of EdU staining positive cells and cell clones. More importantly, SAHA could dose-dependently decrease the expression of HDAC7 and FGF18 compared with control group.

CONCLUSION: SAHA could inhibit the proliferation of CM cell line C918 by inhibiting the HDAC7/FGF18 signaling pathway.