MIF和Cyclin D1在肝细胞癌中的表达

目的 探讨巨噬细胞游走抑制因子(macrophage migration inhibitory factor,MIF)和细胞周期蛋白D1(cyclin D1)在原发性肝细胞癌(hepatocellular carcinoma,HCC)组织中的表达及两者在肝癌发病机制及细胞周期调控中的关系.方法 应用定量PCR及Westem blot技术检测MIF和Cyclin D1在肝癌组织和癌旁组织的表达.化学合成MIF siRNA,将PLC细胞和HepG2细胞分成对照组、MIF siRNA 50 nmol/L干预组、MIF siRNA 1130 nmol/L干预组,脂质体法转染肝癌细胞PLC和HepG2,定量PCR技术和Western blot检测MIF siRNA干扰后MIF和Cyclin D1 mRNA和蛋白的表达变化.结果 MIF和Cyclin D1蛋白在肝癌组织中的相对表达量为0.825±0.13和0.843±0.104;MIF和Cyclin D1 mRNA在肝癌组织中的相对表达量为癌旁组织的(7.31±1.85)倍和(4.27±1.05)倍,与癌旁组织相比,差异均具有统计学意义(FMIF=15.5,P<0.01;fCyclin D1=87.5,P<0.01).应用小RNA干扰技术转染PLC和HepG2肝癌细胞后MIF mRNA分别下调71.2%±7.2%、87.4%±2.9%、74.3%±8.9%、88.4%±4.6%(FPLC=315.5,P<0.01;FHHepG2=201.2,P<0.01);MIF蛋白分别下调为0.33±0.03、0.11±0.02、0.81±0.08、0.36±0.02,并呈剂量依赖关系(FPLC=43.9,P<0.01;FHepG2:133.4,P<0.01).伴随MIF mRNA和蛋白的表达F调Cyclin D1 mRNA分别下调68.2%±3%、78.1%±1.4%、65.8%±4.7%、77.3%±2.6%(FPLC=1569,P<0.01;FHepG2=480.4,P<0.01);Cyclin D1蛋白下调0.28±0.06、0.15±0.03、0.44±0.04、0.13±0.02,亦呈剂量依赖关系,与对照组相比差异有统计学意义(P<0.01),两干预组相比差异有统计学意义(FPLC=35.5,P<0.01;FHepG2=114.7,P<0.01).结论 MIF和Cyclin D1在肝细胞癌中过表达,MIF可能在转录水平调控Cyclin D1的表达,并促使肿瘤细胞通过细胞周期检测点,继续增值和分化,导致肿瘤的形成.

The expression of MIF and Cyclin D1 in hepatocellular carcinoma

Objective To investigate the expression of macrophage migration inhibition factor (MIF) and cell cycle regulating factor Cyclin D1 in hepatocellular carcinoma tissue and the interaction between MIF and Cyclin D1 in hepatocellular carcinoma cell cycle controlling. Methods Using quantitative real-time PCR and Western blotting to detect mRNA and protein expression of MIF and Cyelin DI in HCC tissues and tumor adjacent tissues. Specific small interfering RNA(siRNA) targeting MIF gene was transfccted at doses of 50 nmol/L and 100 nmoL/L into HCC cell lines of PLC and HepG2 with lipofeetamine 2000 methods to knockdown the expression of M1F gene and to investigare the the interaction between M1F and Cyclin D1. Results MIF and Cyclin D1 protein and mRNA were overexpressed in HCC tumor tissues. The relative expression of MIF,Cyclin D1 protein and mRNA were 0.825±0.13,0.843± 0.104 and 7.31±1.85 folds、4.27±1.05 folds, compared with the tumor adjacent tissues (FMIF= 15.5, P<0.01;FCyclin D1=87.5,P <0.01). In MIF siRNA treated PLC and HepG2 cells, MIF mRNA down regulation 71.2%±7.2%, 87.4%±2.9% ,74.3%±8.9% and 88.4%±4.6% respectively (FPLC = 315.5 ,P < 0.01 ; FHepG2= 201.2 P < 0.01). While MIF protein expression were significandy reduced to 0.33±0.03,0.11±0.02, 0.81±0.08 and 0.36±0.02 in a dose-dependent manner (FPLC= 43.9, P <0.01 ;FHepG2 = 133.4 P <0.01). Cyclin D1 mRNA was significantly down-regnlated in MIF siRNA treated PLC and HepG2 cell lines when compared with control group(P <0.01). In 50 nmol/L and 100 nmol/L groups, Cyclin DI mRNA levels were respectively decreased by 68.2%±3% and 78.1%±1.4% in PLC cell, 65.8%±4.7% and 77.3%±2.6% in HepG2 cell (FPLC= 1569, P < 0.01 ; FHepG2= 480.4, P <0.01). Compared with control groups, Cyclin D1 protein levels significantly reduced to 0.28±0.06、0.15±0.03 and 0.44 ±0.04、0.13±0.02 in the PLC and HepG2 after M IF siRNA treatment(FPLC= 35.5, P < 0.01 ; FHepG2 = 114.7, P < 0.01). Conclusions MIF and Cyclin D1 mRNA and protein were overexpressed in HCC tumor tissues and participated in tumor cell cycle regulation. MIF may up-regnlate the expression of Cyclin DI via ERK signalling and precipitate in carcinogenesis of hepatocellular carcinoma.