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目的研究磷脂酶Cγ1(PLCγ1)及NF κB在结直肠癌细胞与细胞外基质黏附中的作用及其信号转导机制。方法PLC抑制剂U73122用于研究PLCγ1在高转移的人结肠癌细胞LoVo和低转移的SW480细胞中对于细胞基质黏附的影响。吡咯二硫氨基甲酸酯(PDTC)用于研究NF κB在结直肠癌细胞与基质黏附中的作用。PLCγ1在结直肠癌细胞中作用的信号转导机制采用蛋白质印迹及凝胶迁移率变动分析(EMSA)。结果抑制PLCγ1对SW480细胞与基质的黏附无明显影响。但在LoVo细胞中,PLCγ1和NF κB的抑制均可显著降低细胞与基质的黏附(P<0.05)并呈剂量依赖性,且抑制作用可被EGF部分恢复。蛋白质印迹分析显示EGF可刺激PLCγ1的磷酸化。EMSA结果显示,抑制PLCγ1可以抑制EGF刺激的NF κB的激活。结论EGF PLCγ1 NF κB信号通路在高转移的结肠癌细胞与基质的黏附中发挥重要作用。
Objective To study the role of phospholipase Cγ1 (PLCγ1) and NF κB in the adhesion of colorectal cancer cells to extracellular matrix and its signal transduction mechanism. Methods The PLC inhibitor U73122 was used to study the effect of PLCγ1 on cell matrix adhesion in highly metastatic human colon cancer cells LoVo and low metastatic SW480 cells. Pyrrolodithiocarbamate (PDTC) was used to study the role of NF-κB in the adhesion of colorectal cancer cells to the matrix. The signaling mechanism of PLCγ1’s role in colorectal cancer cells was analyzed by Western blotting and gel mobility shift assay (EMSA). Results Inhibition of PLCγ1 on SW480 cells and matrix adhesion no significant effect. However, in LoVo cells, the inhibition of PLCγ1 and NFκB could significantly reduce the cell-matrix adhesion (P <0.05) in a dose-dependent manner, and the inhibition could be partially restored by EGF. Western blot analysis revealed that EGF stimulates PLCγ1 phosphorylation. EMSA results showed that inhibition of PLCγ1 inhibited EGF-stimulated NF-κB activation. Conclusion The EGF PLCγ1 NF κB signaling pathway plays an important role in the adhesion of highly metastatic colon cancer cells to the stroma.