Key Laboratory of Agro-products Processing, Ministry of Agriculture, Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
World J Gastroenterol. 2013 Jun 7;19(21):3300-8. doi: 10.3748/wjg.v19.i21.3300.
To investigate the effects of proteins purified from sweet potato storage roots on human colorectal cancer cell lines.
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Hoechst 33258 nuclear staining and Boyden transwell chamber methods were used to determine whether purified sweet potato protein (SPP) from fresh sweet potato roots affected proliferation, migration and invasion, respectively, of human colorectal cancer SW480 cells in vitro. The inhibitory effects of SPP on growth of human colorectal cancer HCT-8 cells intraperitoneally xenografted in nude mice and spontaneous lung metastasis of murine Lewis lung carcinoma 3LL cells subcutaneously transplanted in C57 BL/6 mice were also investigated in vivo.
SPP inhibited the proliferation of SW480 cells in a dose-dependent manner, with an IC50 value of 38.732 μmol/L (r (2) = 0.980, P = 0.003) in the MTT assay. Hoechst 33258 nuclear staining further revealed inhibition of cell viability and induction of apoptosis by SPP. The transwell assay disclosed significant reduction in migrated cells/field by 8 μmol/L SPP (8.4 ± 2.6 vs 23.3 ± 5.4, P = 0.031) and invaded cells/field through the ECMatrix by 0.8 μmol/L SPP, compared with the control (25.2 ± 5.2 vs 34.8 ± 6.1, P = 0.038). Both intraperitoneal (ip) and intragastric (ig) administration of SPP led to significant suppression of growth of intraperitoneally inoculated HCT-8 cells in nude mice to 58.0% ± 5.9% (P = 0.037) and 43.5% ± 7.1% (P = 0.004) of the controls, respectively, after 9 d treatment. Bloody ascites additionally disappeared after ip injection of trypsin inhibitor. Notably, ig and ip administration of SPP induced a significant decrease in spontaneous pulmonary metastatic nodule formation in C57 BL/6 mice (21.0 ± 12.3 and 27.3 ± 12.7 nodules/lung vs 42.5 ± 4.5 nodules/lung in controls, respectively, P < 0.05) after 25 d treatment. Moreover, the average weight of primary tumor nodules in the hind leg of mice decreased from 8.2 ± 1.3 g/mice in the control to 6.1 ± 1.4 g/mice in the ip group (P = 0.035).
SPP exerts significant antiproliferative and antimetastatic effects on human colorectal cancer cell lines, both in vitro and in vivo.
研究甘薯贮藏根中分离得到的蛋白质对人结直肠癌细胞系的影响。
采用 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）法、Hoechst 33258 核染色和 Boyden 小室迁移实验，分别检测新鲜甘薯根中分离得到的甘薯蛋白（SPP）对体外人结直肠癌细胞 SW480 增殖、迁移和侵袭的影响。还在体内研究了 SPP 对裸鼠皮下接种人结直肠癌细胞 HCT-8 细胞和 C57BL/6 小鼠皮下接种鼠 Lewis 肺癌 3LL 细胞自发肺转移的抑制作用。
SPP 呈剂量依赖性抑制 SW480 细胞的增殖，MTT 法 IC50 值为 38.732 μmol/L（r (2) = 0.980，P = 0.003）。Hoechst 33258 核染色进一步显示 SPP 抑制细胞活力并诱导细胞凋亡。Transwell 实验显示，与对照组相比，8 μmol/L SPP 处理后穿过 ECMatrix 的迁移细胞/视野显著减少（8.4 ± 2.6 比 23.3 ± 5.4，P = 0.031），0.8 μmol/L SPP 处理后穿过 ECMatrix 的侵袭细胞/视野也显著减少（25.2 ± 5.2 比 34.8 ± 6.1，P = 0.038）。SPP 腹腔（ip）和灌胃（ig）给药均显著抑制裸鼠腹腔接种的 HCT-8 细胞的生长，分别为对照组的 58.0% ± 5.9%（P = 0.037）和 43.5% ± 7.1%（P = 0.004），治疗 9 天后。此外，ip 注射胰蛋白酶抑制剂后，血性腹水也消失了。值得注意的是，ig 和 ip 给予 SPP 后，C57BL/6 小鼠自发肺转移结节形成明显减少（分别为 21.0 ± 12.3 和 27.3 ± 12.7 个结节/肺与对照组的 42.5 ± 4.5 个结节/肺相比，P < 0.05），治疗 25 天后。此外，对照组小鼠后腿原发性肿瘤结节的平均重量从 8.2 ± 1.3 g/小鼠降至 ip 组的 6.1 ± 1.4 g/小鼠（P = 0.035）。
SPP 在体外和体内对人结直肠癌细胞系均表现出显著的增殖抑制和抗转移作用。
