Expression Of RKIP And Hpa In Hepatocellular Carcinoma And Their Clinical Significance

Primary liver cancer is one of the most common malignant tumors inChina.Annually,there is about620,000new cases of liver cancer patientsissued around the world.In our country, new cases of liver cancer patientsaccount for42.5%of the global total,and the incidence rate shows anincreasing trend.The main cause of primary liver cancer disease isposthepatitic cirrhosis in our country.In the United States and Europe, long-term alcohol abuse caused alcoholic cirrhosis is common.In addition, aflatoxincontamination with food,blue-green algae toxoid pollution in water, hepaticmetabolism and autoimmune disease,cryptogenic liver disease or cryptogenicliver cirrhosis and so on relate to it.From the perspective of pathologicaltypes,the primary liver cancer can be divided into hepatocellularcarcinoma(HCC),intrahepatic cholangiocarcinoma(ICC)and hepatocellularcarcinoma-the mixed type of intrahepatic cholangiocarcinoma.This studyaimes to hepatocellular carcinoma,which accounts for more than90%and hashigh degree of malignancy,insidious onset,recurrence,metastasis.After surgicalresection,3-year survival rate is about40-50%,while the5-year survival rateonly about20%and the2-year recurrence rate as high as40-60%.Lowsurvival rate and high recurrence rate are related to biological characteristic ofHCC which is easy invasion and metastasis.Invasion and metastasis of HCC isa complex and multi-step process,including HCC cells detachment, migration,adhesion and growth.A number of studies have shown that the invasion andmetastasis of HCC is related to the changes of some genes and abnormalexpression of their corresponding protein factors. But the exact mechanismremains unclear,so the regulatory mechanism of HCC's invasion andmetastasis in the level of molecular has become a hot topic of the presentstudy. In1984,Bernier[1]firstly from bovine brain tissue purified a highlyconserved cytoplasmic protein,which had the role of fat metabolism andphospholipid membrane synthesis and classified it as the phosphatidy-lethanolamine binding protein family named PEBP-1. Yeung[2]firstly reportedin Nature journal in1999that PEBP was related to the Raf-1-MEK-ERKsignaling pathway named RKIP.In2003,FU[3]firstly discovered the metastasissuppressor function of RKIP.He found that the expression level of RKIP in themetastatic prostate cancer is lower than the non-metastatic prostate cancer andup-regulating RKIP in prostate cancer cells can reduce the invasive ability ofcancer cells,so he regarded RKIP as an independent prognostic indicator andengaged in a wide range related research of RKIP and malignant tumor.Toescape into the circulatory system from the tumor lesion,tumor cells must passthrough the barrier of the basement membrane and extracellular matrixcomposition.The major component of the barrier is the structure of proteinsand sulfate heparan proteoglycan(HSPG).Heparanase is a only bioactiveenzyme,which can degrade heparan sulfate(HS)in organisms.Recently,manylarge study find that the HPA has a close relationship to the malignant tumorinvasion and metastasis.But its specific regulatory mechanism is unknown,Hong[4]think that HPA gene overexpression may associate with protein kinaseB(AKT)phosphorylation.Besides,Smizu[5]think that HPA overexpression intumors may relate to the gene promoter methylation.De Mestre[6]find that thetranscription factor(Egrl)can induce the transcription of HPA,which may relateto Egrl.As a tumor suppressor gene,RKIP involves in the regulation of Raf-1/MEK/ERK,G-proteins coupled receptors,NF-κB and other signaling pathways.Speaking in theory,RKIP may participate in the regulation of HPA.Objective:To investigate the expression of Raf kinase inhibitorprotein(RKIP) and heparanase(HPA)in Human hepatocellular Carcinomatissues,tumor-surrounding tissues and normal liver tissues. To discuss theircorrelation with clinical pathological factors and to analysis correlationbetween RKIP and HPA in HCCs.Methods:We collected42cases of hepatocellular Carcinoma tissues,36 cases of tumor-surrounding tissues and23cases of normal liver tissues whichwere from surgical resection in Hepatobiliary Surgery, Fourth Hospital,HebeiMedical University.All cases were confirmed by pathology. Immunohisto-chemistry was used to detect the expression of RKIP and HPA protein in42cases of HCC tissues,36cases of tumor-surrounding tissues and23cases ofnormal liver tissues.And then analysis software SPSS13.0was determined toaccess their relationship with clinical pathological factors and the correlationbetween them. Expression differences of RKIP and HPA among HCC tissues,tumor-surrounding tissues and normal liver tissues use Kruskal-Wallisrank-sum test.Mann-Whitney U test was used to analysis pairwise compari-sons.Using Spearman,s rank correlation test to analysis correlation betweenRKIP and HPA.Using χ2test to analysis correlation between RKIP, HPA andclinical pathological factors.P<0.05was considered statistical significance.Results:1,Expression of RKIP was high in normal liver tissues,whichwas decreased in tumor-surrounding tissues.In hepatocellular Carcinomatissues RKIP was low or even no expression. Positive rates of RKIP inhepatocellular Carcinoma tissues,tumor-surrounding tissue and normal livertissues were28.57%,80.56%and95.65%.Expression of RKIP in hepatocellu-lar Carcinoma tissues was lower than tumor-surrounding tissues and normalliver tissues,and the difference had statistical significance (χ2=26.597;P=0.000).The difference between tumor-surrounding tissues and normal livertissues didn't have statistical significance.(P=0.303).2,The expression of HPA was low or even no expression in normal livertissues,which was increased in tumor-surrounding tissues.In hepatocellularCarcinoma tissues HPA was high expression. Positive rates of HPA inhepatocellular Carcinoma tissues,tumor-surrounding tissue and normal livertissues were83.33%,72.22%and8.69%.The expression of HPA inhepatocellular Carcinoma tissues was higher than tumor-surrounding tissuesand normal liver tissues,and the difference had statistical significance(χ2=36.722;P=0.000).The difference between tumor-surrounding tissues andnormal liver tissues also had statistical significance.(P=0.000). 3,The expression of RKIP and HPA was irrelevant with age, sex, AFPlevel, tumor size(P>0.05),while was relevant with having liver inside or thelymph node metastasis and pathological grade(P<0.05).The expression ofRKIP in HCCs with intrahepatic or lymph node metastasis was lower than thatwithout intrahepatic or lymph node metastasis,which in well differentiatedgroup was higher than in poorly differentiated group.The expression of HPA inHCCs with intrahepatic or lymph node metastasis was higher than that withoutintrahepatic or lymph node metastasis,which in well differentiated group waslower than in poorly differentiated group.4,There was a significantly negative relationship between the expressionof RKIP and HPA in HCCs (r=-0.409,P=0.007).Conclusion:1,The expression of RKIP in HCC was significantly lowerthan that in tumor-surrounding tissue and in normal liver tissue, indicating thatRKIP was related to the development and the occurrence of HCC.2,The expression of RKIP in HCC with intrahepatic or lymph nodemetastasis and poorly differentiated was significantly increased, indicatingthat RKIP was related to the invasion and metastasis of HCC and may inhibitHCC's metastasis.3,The expression of HPA in HCC was significantly higher than that intumor-surrounding tissue and in normal liver tissue,indicating that HPA wasrelated to the development and the occurrence of HCC.4,The expression of HPA in HCC with intrahepatic or lymph nodemetastasis and poorly differentiated was significantly decreased, indicatingthat RKIP was related to the invasion and metastasis of HCC and maypromote HCC's metastasis.5,Low-expression or absence of RKIP and over-expression of HPA arerelated to invasion and metastasis of HCC,and the expression of RKIP andHPA has significant negative correlation.RKIP may through the Raf-1-MEK1/2-ERK1/2or the NF-κB pathway to inhibit expression of HPA.