木犀草素通过抑制IL-6/STAT3信号通路抑制结肠癌细胞生长

Luteolin Suppresses the Growth of Colon Cancer Cells by Inhibiting the IL-6/STAT3 Signaling Pathway

目的探究木犀草素抑制结肠癌细胞生长的相关机制。方法反转录定量聚合酶链反应(reverse transcription quantitative polymerase chain reaction,RT-qPCR)和Western blot法分析木犀草素对白细胞介素(interleukin,IL)-6/信号转导和转录激活因子3(STAT3)/磷酸化STAT3。采用酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)分析IL-6的蛋白分泌情况。细胞增殖实验和Transwell实验分别用于分析木犀草素和IL-6在结肠癌细胞中的生长和迁移。结果脂多糖(lipopolysaccharides,LPS)刺激促进巨噬细胞M1型极化,增加IL-6的表达和分泌,而木犀草素抑制了LPS的上述作用。M1型极化增加了结肠癌细胞(SW620和SW480)的增殖速度、迁移和侵袭能力以及STAT3的磷酸化。木犀草素通过减少M1型极化来抑制这些效应。为了证实木犀草素的作用是通过IL-6/STAT3信号通路介导的,笔者用重组IL-6蛋白和抗IL-6抗体处理SW620和SW480细胞研究,发现IL-6促进细胞增殖,增强迁移和侵袭,并增加STAT3磷酸化,与抗IL-6抗体效果相反。此外,IL-6促进LPS诱导的M1型极化,而抗IL-6抗体增强了木犀草素诱导M1型极化降低的作用。结论木犀草素通过抑制IL-6/STAT3信号通路抑制结肠癌细胞的生长、迁移和侵袭能力。

Objective To investigate the mechanism of the inhibitory effect of luteolin on the growth of colon cancer cells.Methods Reverse transcription quantitative polymerase chain reaction(RT-qPCR)and Western blot were used to analyze the effects of luteolin on interleukin(IL)-6/signal transducer and activator of transcription 3(STAT3)/phospho-STAT3.Enzyme-linked immunosorbent assay was used to analyze the protein secretion of IL-6.Proliferation and Transwell assays were used to analyze the growth and migration of luteolin and IL-6 in colon cancer cells,respectively.Results Stimulation with lipopolysaccharides(LPS)promoted the M1 polarization of macrophages and increased the expression and secretion of IL-6.However,the presence of luteolin inhibited the effects of LPS.M1 polarization increased the proliferation rate,migration and invasion ability,and phosphorylation of STAT3 in colon cancer cells(SW620 and SW480).Luteolin inhibited these effects by reducing M1 polarization.To confirm that the action of luteolin was mediated by IL-6/STAT3signaling,we treated SW620 and SW480 cells with recombinant IL-6 protein and anti-IL-6 antibody.We observed that IL-6 promoted cell proliferation,enhanced migration and invasion,and increased STAT3 phosphorylation.The opposite effect was observed with the anti-IL-6 antibody.In addition,IL-6 promoted LPS-induced M1 polarization,while the anti-IL-6 antibody enhanced the decrease in luteolin-induced M1 polarization.Conclusion Luteolin suppressed the growth and migration/invasion of colon cancer cells by inhibiting the IL-6/STAT3 signaling pathway.