葡萄膜黑色素瘤 (uveal melanoma)是成人眼睛中最常見的原發性惡性腫瘤,主要見於高加索人。葡萄膜黑色素瘤的局部腫瘤控制非常好,但這種惡性腫瘤與繼發性轉移有相對較高的死亡率。漆黃素 (Fisetin)是一種日常飲食可以攝取的類黃酮類 (flavonoid)化合物,具有各種抗癌作用。本研究目的是利用體外培養的葡萄膜黑色素瘤細胞(SP6.5及M17 cell)與正常視網膜色素上皮細胞(retinal pigment epithelial cell ; RPE cell)相比較,探討漆黃素在活體內的抗腫瘤作用。我們使用細胞存活率分析評估漆黃素的細胞毒性作用,利用流式細胞儀分析來測定細胞凋亡,使用螢光微量盤分析儀確定粒線體跨膜電位的變化。結果顯示漆黃素能依劑量增加而降低葡萄膜黑色素瘤細胞的細胞存活率,但郤不影響視網膜色素上皮素細胞的細胞存活率。漆黃素可以有效率的誘導葡萄膜黑素瘤細胞凋亡,抑制抗細胞凋亡B細胞淋巴瘤-2 (B-cell lymphoma-2; Bcl-2) 家族的表現並損傷該細胞粒線體跨膜電位,並增加促進細胞凋亡的Bcl-2蛋白、細胞色素 C 和各種蛋白酶之表現活性。漆黃素選擇性的誘導葡萄膜黑色素瘤細胞凋亡,有希望成為治療葡萄膜黑色素瘤方式之一。
Uveal melanoma (UM) is the most common intraocular malignancy in adult, primarily found in Caucasian populations. It is a rare disease with good local disease control. Metastatic uveal melanoma was associated with high mortality. Fisetin, a diatery flavonoid, has been reported to possess anticancer effects in various cancers. The purpose of the study was to investigate the antitumor effects of fisetin in SP6.5 and M17 uveal melanoma cell lines. We also evaluated the cytotoxicity of fisetin in normal retinal pigment epithelial (RPE) cells. MTT assay was used for evaluating cytotoxic effects of fisetin. Flow cytometry analysis was used for the determination of apoptosis. JC-1 fluorescent staining was used to determine mitochondrial transmembrane potential changes. The results showed that fisetin concentration-dependently decreased the cell viability of uveal melanoma cells but did not influenced the cell viability of RPE cells. Apoptosis of uveal melanoma cells was induced by fisetin significantly. Fisetin inhibited antiapoptotic Bcl-2 family proteins and induced the damage of mitochondrial transmembrane potential. The levels of proapoptotic Bcl-2 proteins, cytochrome c, and various caspase activities were increased by fisetin. In conclusion, fisetin induces apoptosis of uveal melanoma cells selectively and may be a promising agent for the treatment of uveal melanoma.