α-Linolenic acid (ALA, 18:3n-3) and γ-gamma linolenic acid (GLA, 18:3n-6) are polyunsaturated fatty acids (PUFA) that improve the human health. The present study focused on testing the in vitro antitumor actions of pure ALA and GLA on the HT-29 human colorectal cancer cell line. Cell viability was checked by MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, cell membrane damage by the lactate dehydrogenase assay, apoptosis was tested by both caspase-3 activity trial and transmission electron microscopy images, and protein composition was analyzed by quantitative proteomics analysis. MTT test revealed IC₅₀ values of 230 and 255 μM for ALA and GLA, respectively, at 72 h. After 24 h of incubation, both ALA and GLA induced apoptosis on HT-29 colorectal cancer cells according to the caspase-3 assay and microscopy images. SWATH/MS analysis evidenced that ALA significantly affected the mitochondrial protein import pathway and the citric acid cycle pathway, while GLA did not significantly affect any particular pathway. In summary, both ALA and GLA showed concentration-dependent inhibitory effects on HT-29 cells viability and induced cell death by apoptosis. ALA significantly affected cellular pathways, while GLA does not have specific actions on either pathway. Both n-3 and n-6 C18 PUFA are bioactive food components useful in the colorectal cancer prevention.

中文翻译：

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α-亚麻酸和γ-亚麻酸对HT-29人结肠直肠癌细胞具有不同的抗肿瘤作用。

α-亚麻酸（ALA，18：3 n -3）和γ-γ亚麻酸（GLA，18：3 n -6）是改善人体健康的多不饱和脂肪酸（PUFA）。本研究集中于测试纯ALA和GLA对HT-29人结肠直肠癌细胞系的体外抗肿瘤作用。通过MTT（（3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide）测试来检测细胞活力，通过乳酸脱氢酶测定来检测细胞膜损伤，并通过两个caspase-3活性试验来测试细胞凋亡。透射电镜图像和蛋白质组成进行定量蛋白质组学分析，MTT测试显示IC ₅₀在72小时时，ALA和GLA的取值分别为230和255μM。温育24小时后，根据caspase-3测定和显微镜图像，ALA和GLA均诱导HT-29结肠直肠癌细胞凋亡。SWATH / MS分析表明，ALA显着影响线粒体蛋白的导入途径和柠檬酸循环途径，而GLA并未显着影响任何特定途径。总之，ALA和GLA均显示出对HT-29细胞活力的浓度依赖性抑制作用，并通过凋亡诱导细胞死亡。ALA显着影响细胞途径，而GLA在这两种途径上均没有特异性作用。既Ñ -3和Ñ -6 C18 PUFA是在结肠直肠癌预防有用的生物活性食物成分。