紫草素调控Wnt/β-catenin抑制腺瘤性结肠息肉突变结肠癌细胞生长

Shikonin Inhibits APC-mutant Colon Cancer via Wnt/β-catenin Signaling

目的发现腺瘤性结肠息肉(APC)突变结肠癌的小分子抑制剂,为结肠癌靶向治疗提供先导化合物。方法构建稳定表达7*Tcf-GFP/SV40-Cherry(7TGC)双重荧光报告系统的APC突变结肠癌细胞系用于小分子抑制剂筛选。细胞活力测定、克隆形成、EdU和动物移植瘤实验检测小分子对体内外APC突变结肠癌的抑制作用,免疫印记和免疫共沉淀实验探究其分子机制。结果发现了4个抑制APC突变结肠癌细胞Wnt活性的小分子,其中紫草素显著抑制APC突变结肠癌的细胞活力和增殖能力并诱导细胞凋亡;移植瘤实验结果表明紫草素显著减缓体内瘤体生长;免疫印记和免疫共沉淀实验进一步发现紫草素可显著减少β-catenin的水平。结论紫草素可显著抑制APC突变结肠癌的Wnt活性和肿瘤生长。

Objective To identify small molecule inhibitors of APC-mutant colon cancer and provide lead compounds for targeted therapy of colon cancer.Methods APC-mutant colon cancer cell lines that stably express 7*Tcf-GFP/SV40-Cherry(7TGC)dual fluorescence reporter system was constructed for smallmolecule inhibitor screening.Cell viability,colony formation,EdU incorporation,and xenograft tumor assay were used to evaluate the inhibitory effect of these inhibitors on APC-mutant colon cancer in vitro and in vivo.Western blot and co-immunoprecipitation assays were used to explore the molecular mechanism.Results Four small molecules that inhibited Wnt activity in APC-mutant colon cancer cells were discovered.Shikonin exhibited significant inhibition of cell viability and proliferation while inducing apoptosis of APC-mutant colon cancer cells.Xenograft tumor assay demonstrated that shikonin significantly reduced tumor growth in vivo.Furthermore,Western blot and co-immunoprecipitation assays revealed that shikonin markedly decreased β-catenin levels.Conclusion Shikonin effectively inhibits Wnt activity and suppresses tumor growth in APC-mutant colon cancer.