木犀草素对结肠癌细胞生长的影响及作用机制研究

Effect and action mechanism of luteolin on cell growth of colon cancer

目的 探讨木犀草素对结肠癌细胞生长的影响,并进一步明确木犀草素是否通过调节免疫细胞活性抑制肿瘤生长。方法 对小鼠结肠癌细胞系(MC-38、CT-26、CMT-93)和人结肠癌细胞系(Caco-2)进行体外培养,观察不同浓度(0、1、5、10、20μmol/L)木犀草素对结肠癌细胞增殖、凋亡及迁移的影响结果。构建小鼠结肠癌细胞MC-38荷瘤模型,观察木犀草素治疗对肿瘤生长和荷瘤小鼠生存期的影响。体外检测不同浓度木犀草素对小鼠脾脏免疫细胞及人外周血淋巴细胞活性的影响。结果 木犀草素在5μmol/L浓度下即可显著抑制小鼠结肠癌细胞系CT-26增殖,10μmol/L浓度可显著抑制小鼠结肠癌细胞系MC-38、CMT-93增殖,20μmol/L浓度可显著抑制人结肠癌细胞系Caco-2增殖;木犀草素可显著抑制小鼠结肠癌细胞系CT-26分裂并促进其凋亡,还可显著抑制小鼠结肠癌细胞系MC-38的迁移能力;20 mg/kg木犀草素体内治疗可显著抑制结肠癌细胞MC-38荷瘤小鼠肿瘤生长,并显著延长荷瘤小鼠的生存期。不同浓度木犀草素体外刺激对小鼠脾脏免疫细胞的增殖均无显著影响,但1μmol/L浓度木犀草素即可显著上调小鼠CD8;T细胞和自然杀伤(NK)细胞表面活化型受体NKG2D的表达,10μmol/L木犀草素(效靶比为3∶1时)还可显著上调CD8;T细胞和NK细胞对靶细胞的杀伤活性。木犀草素体外刺激可诱导人外周血CD8;T细胞表面活化型分子CD69、NKG2D表达显著上调。结论 木犀草素可抑制结肠癌细胞增殖及迁移,并可增强免疫细胞活性抑制肿瘤生长。

Objective To investigate the effect of luteolin on the growth of colon cancer cells,and to further clarify whether luteolin inhibits tumor growth or not by regulating the activity of immune cells. Methods Mouse colon cancer cell lines(MC-38,CT-26,CMT-93) and human colon cancer cell lines(Caco-2) were cultured in vitro,the effects of luteolin on proliferation,apoptosis and migration of colon cancer cells at different concentrations(0,1,5,10,20 μmol/L)were observed. The tumor bearing model of mouse colon cancer cell MC-38 was constructed to observe the effects of luteolin on tumor growth,apoptosis and migration of cancer cells. The effect of luteolin on activity of mouse spleen immune cells and human peripheral blood lymphocytes was detected in vitro. Results Luteolin at concentration of 5 μmol/L significantly inhibited the proliferation of mouse colon cancer cell line CT-26;luteolin at concentration of 10 μmol/L significantly inhibited the proliferation of mouse colon cancer cell line MC-38 and CMT-93;luteolin at concentration of 20 μmol/L significantly inhibited the proliferation of human colon cancer cell line Caco-2. Luteolin significantly inhibited the division and apoptosis of mouse colon cancer cell line CT-26,and significantly inhibited the migration of mouse colon cancer cell line MC-38. Treatment with luteolin at 20 mg/kg body weight significantly inhibited tumor growth and prolonged survival of colon cancer MC-38 bearing mice in vivo. In vitro different concentrations of luteolin stimulation did not affect the proliferation of mouse spleen immune cells,but significantly upregulated the expression of NKG2D on mouse CD8+T cells and natural killer( NK)cells. Luteolin at concentration of 10 μmol/L( effect target ratio of 3 to 1) could significantly upregulate the killing activity of CD8+T cells and NK cells against target cells. Luteolin stimulation up-regulated expressions of CD69 and NKG2D in human peripheral blood CD8+T cells in vitro.Conclusion Luteolin inhibits the growth of colorectal cancer cells,promotes the activity of immune cells and inhibits tumor growth.