姜黄素衍生物体外抑制结肠癌细胞增殖侵袭作用

Inhibitory effects of curcumin derivatives on proliferation and invasion of human colon cancer cell line Lovo and SW480

背景与目的：姜黄素（curcumin）是从天然植物姜黄中提取的酚类化合物，已证实其具有抗恶性肿瘤作用。近年人工合成的姜黄素衍生物被认为抗癌作用和生物利用度优于母体姜黄素，但是对于结肠癌细胞的作用鲜见报道。研究旨在比较天然植物姜黄素及其4种人工合成的衍生物T316、T62、T63、T6F4对结直肠癌细胞株Lovo和HSW480的细胞毒性作用、增殖迁移抑制作用和核转录因子（NF—κB）活性表达的影响。方法：培养人结肠癌细胞系Lovo和SW480，然后通过MTT分析检测姜黄素及4种衍生物对结肠癌细胞株Lovo和SW480细胞毒性影响；细胞划痕实验检测对结肠癌细胞迁移抑制作用；软琼脂克隆形成实验检测对癌细胞克隆增殖影响；流式细胞技术检测对癌细胞凋亡的影响；并通过荧光素酶双报告基因法检测姜黄素及其衍生物对NF—κB活性表达的影响。结果：姜黄素对Lovo和SW480的半数有效抑制浓度（IC50）分别为（14．2±0．2）μmol／L和（10．6±0．7）μmol／L，分别是4种衍生物对Lovo和NSW480的7．0-8．7倍和5．7～7．8倍（P〈0．01）。不加任何药物时，Lovo24h迁移距离为（160．7±18．4）μm，SW480为（389．9±8．9）μm，但加入姜黄素及4种衍生物后，细胞迁移距离均明显缩短，距离最短是T63作用于Lovo时的（53．2±11．7）μm；T316作用于SW480时的（80．4±9．6）μm。4种衍生物的迁移距离明显短于姜黄素的迁移距离（P〈0．05）。4种衍生物在抑制2株结肠癌细胞克隆形成方面也明显优于姜黄素母体（P〈0．05）。通过流式细胞检测发现，姜黄素及4种衍生物诱导Lovo的凋亡率分别为（10．05±0．54）％、（55．32±2．86）％、（31．83±0．85）％、（26．01±0．44）％、（21．44±3．01）％，高于对照组的凋亡率（6．98±0．23）％（P〈0．05）；且4种衍生物诱导凋亡作用优于姜黄素（P〈0．05）。荧光素酶报告基因检测结果表明，姜黄素及其4种衍生物能下调TNF—α诱导的NF—κB的转录活性。结论：姜黄素和4种衍生物均能抑制结直肠癌细胞的增殖迁移力，促进结直肠癌细胞的凋亡，但4种衍生物的作用明显优于母体姜黄素。

Background and purpose： Curcumin is a phenolic compound extracted from the natural plant turmeric, which confer an antitumor effect. Recently, it was found that some curcumin derivatives also possessed the inhibiting effects on tumor angiogenesis and metastasis, even stronger than curcumin itself. However, no study dealing with their anticancer effect on colorectal cancer cells in vitro has been reported by far. This study aimed to investigate the roles of curcumin and its 4 derivatives, T316, T62, T63, and T6F4 in the proliferation and invasion of human colon cancer cell line Lovo and SW480. Methods： The inhibitory effects of curcumin and novel structural analogues T316, T62, T63, and T6F4 in 2 kinds of human colorectal cancer cell lines, SW480 and Lovo were investigated by MTT- based assay, Scratch-wound assay, soft agar colony formation assay, and flow cytometry. The transcriptional activity of NF-κB promoter was detected by luciferase assay. Results： The IC50 of curcumin were （14.2±0.20） μmol/L and （10.6±0.70）μmol/L on Lovo and SW480, respectively, which were 7.0-8.7 folds, and 5.7-7.8 folds, significantly greater than its 4 derivatives in same cell lines （P〈0.01）. The results of Scratch-wound assay revealed that there was a significant reduction within 24 h of cell migration distance in 4 derivative-groups compared with the cucurmin group （160.7±18.4） μm for Lovo, and （389.9±8.9） μm for SW480, respectively （P〈0.05）. Soft agar colony formation assay showed a significant reduction in cloning number of 4 derivative-groups （P〈0.05） compared with the cucurmin group （60±8 for Lovo and 75±5 for SW480）, respectively. The proportion of apoptosis of Lovo cell exposure to 4 derivatives were （55.32±2.86）%, （31.83±0.85）%, （26.01±0.44）%, （21.44±3.01）% in T316, T62, T63, and T6F4, respectively, which were significantly higher than control （6.81±0.23）% and curcumin group （10.05±0.54）% （P〈0.05）. Luciferase assays also showed that treatment with curcumin or its 4 derivatives could inhibit NF-κB activation which induced by TNF-α. Conclusion： Curcumin and its 4 derivatives could inhibit proliferation and migration ability of colorectal cancer cells lines Lovo and SW480, and promoted cells apoptosis. Furthermore, the effects of 4 derivatives were significantly stronger than curcumin itself.