整合素α6在肝细胞癌黏附过程中诱导PI3K及MAPK双信号传导通路

Integrin α6 induces PI3K and MAPK signal pathway in the adhesion of hepatocellular carcinoma

目的:探讨肝细胞癌与细胞外基质发生黏附过程中所引起的信号转导通路的变化.方法:LN作为细胞外基质,BSA作为对照基质,常规培养人肝细胞癌细胞系BEL-7402细胞;以整合素α6单抗作用后检测细胞黏附于LN之后的变化以及所诱导的信号传导通路.Boyden小室检测细胞迁移及侵袭能力;Western blot分析检测细胞ERK磷酸化,RT-PCR方法检测PI3K及Akt基因mRNA表达的变化.结果:细胞在不同基质上发生黏附的时间为30min-1h,但没有明显差异.细胞在LN基质上的黏附率为187.2%,而以整合素α6抗体作用后黏附率为104.4%,细胞黏附率明显下降(P<0.05).BEL-7402细胞穿过Matrigel发生侵袭的细胞数分别为每高倍视野103.2±16.5个,抗整合素α6单抗10mg/L作用后为88.7±9.9个,有显著性差异(P<0.01);BEL-7402细胞PI3K及Akt的表达在黏附于细胞外基质后明显增加,而且ERK磷酸化明显增加,整合素α6抗体可以部分降低表达及磷酸化.结论:细胞在黏附过程中有PI3K及ERK两条传导信号分子参与,并与整合素α6及LN相关.

AIM： To investigate the changes of signal pathways in the adhesion of hepatocellular carcinoma with extracellular matrix. METHODS： BEL-7402 cells were cultured regularly on media containing laminin （LN） or bovine serum albumin （BSA, served as control matrix）. After treatment with anti-integrin α6 monoclonal antibody, cell changes and integrin α6-induced signal pathways were observed. Boyden chamber was used to detect cell migration and invasion ability. Western blot was adopted to analyze the phosphorylation of ERK. Reverse transcription-polymerase chain reaction （RT-PCR） was employed to measure the expression of PI3K and Akt mRNA.RESULTS： BEL-7402 extracellular matrices cells adhered to different within 30 min to 1h without significance. The rate of cell adhesion on LN-coated substrate was 187.2%, but decreased to 104.4% after anti-integrina6 monoclonal antibody treatment （P 〈 0.05）. The number of BEL-7402 cells migrated through the Matrigel was 103.2 ± 16.5 per high power field （HPF）, and anti-integrin α6 monoclonal antibody inhibited it to 88.7 ± 9.9 （P 〈 0.01）. The expression levels of PI3K and Akt were up-regulated, and phosphorylation of ERK was increased after BEL-7402 cell adhered to LN; however, anti-integrin α6 monoclonal antibody partly inhibited the upregulation and phosphorylation. CONCLUSION： Cultured BEL-7402 cells highly express integrin α6. PI3K and ERK pathway is involved in the adhesion associated with LN and integrin α6.