整合蛋白β1在藻蓝蛋白抑制白血病细胞系K562细胞增殖中的作用

Effects of Integrin β1 on Phycocyanin Inhibiting Proliferation of K562 Cells

本研究观察不同浓度藻蓝蛋白(phycocyanin)对K562细胞增殖的影响,并检测藻蓝蛋白处理后细胞表面整合蛋白β1表达和胞内黏着斑激酶(FAK)基因表达的变化,探讨整合蛋白β1在藻蓝蛋白抑制K562细胞增殖中的可能作用机制。用流式细胞术(FCM)检测藻蓝蛋白处理前后K562细胞表面整合蛋白β1表达变化;MTT法测定不同浓度藻蓝蛋白对K562细胞增殖的影响;RT-PCR检测不同浓度藻蓝蛋白对K562细胞内FAK基因表达的作用。结果表明整合蛋白β1在K562细胞上高表达;藻蓝蛋白不能改变其表达量。不同浓度藻蓝蛋白对K562细胞的增殖均有抑制作用。藻蓝蛋白可上调胞内FAK的基因表达水平,恢复整合蛋白β1介导的细胞增殖抑制信号。结论藻蓝蛋白可能通过增强细胞基质与K562细胞表面的整合蛋白β1结合,上调K562细胞内FAK基因表达水平,恢复整合蛋白β1介导的细胞增殖抑制信号而发挥抑制K562细胞增殖的作用。

This study was purposed to investigate the effect of phycocyamin at different concentration on proliferation of K562 cells, to detect the changes of integrin β1 expression and intracellular focal adhesion kinase （FAK） gene expression on the surface K562 cells treated with phycocyanin, and to explore the possible machanism of integrin β1 effect on phycocyanin inhibiting proliferation of K562 cells. The expression level of integrin β1 on the surface of K562 cells was evaluated by flow cytometry （FCM） ; the growth of K562 cells treated with phycocyanin was measured by MTF assay; the expression level of FAK mRNA was analyzed by relatively quantitative RT-PCR after four-day culture of K562 cells with phycocyanin of 40 μg/ml, 80 μg/ml and 160 μg/ml, respectively. The results showed that integrin β1 expression on the surface of K562 cells was significantly higher than that in bone marrow mononuclear cells （BMMNC） from normal subjects. Phycocyanin could not change the level of integin β1 expression. Phycocyanin could increase the expression of FAK gene on K562 cells and inhibit the proliferation of K562 cells. It is concluded that phycocyanin can inhibit the proliferation of K562 cells through enhancing the conjunction of cell stroma with integrin β1 on K562 cell surface, up-regulating the expression level of FAK gene in K562 cells, restoring the signaling pathway of proliferation inhibition mediated by integrin β1. The possible mechanism of phycocyanin in the proliferation inhibition of K562 cells is to increase the expression of FAK gene. The phcocyanin may be considered as a potential agent for inhibition of cancer cell proliferation.