The Relationship Between The Expression Of Pin1and Clinicopathological Features In Hepatocellular Carcinoma

Objective: To study the expression of Pin1, DAPK1, and β-catenin in hepatocellularcarcinoma (HCC) and the clinicopathologic significance in HCC.Methods:1. To investigate the level of Pin1mRNA in34samples of HCC and correspondingadjacent liver tissues by using Real-time polymerase chain reaction（Real-timePCR）.2. Using Western Blot, to detect the protein expression of Pin1, DAPK1, β-catenin in29samples of HCCs and corresponding adjacent liver tissue.3. Immunohistochemistry (IHC) and high-throughput tissue microarray techniquewere applied to detect the protein expression of Pin1、DAPK1、β-catenin in184samples of HCC and corresponding adjacent liver tissue. Then we evaluate thecorrelation in these three proteins. The relationships between protein expression andHCC clinicopathological parameters and prognosis value were also analyzed.Result:1. Real-time PCR showed that the relative quantity (RQ) of Pin1mRNA in34HCCs was0.866±0.620, and the relative quantity of corresponding adjacent livertissues was1(0). There was no statistically significant difference between the twogroups(P=0.359).2. The result of Western Blot showed that the average level of Pin1protein in HCCswas1.322±0.977, which was higher than corresponding adjacent liver tissues (0.753±0.594), with statistically significant difference (P<0.001), The average level ofDAPK1protein in HCCs (0.523±0.435) was significantly lower than correspondingadjacent liver tissues (1.291±1.185)(P=0.019). The level of β-catenin in HCC(1.532±0.618) was significantly higher than corresponding adjacent liver tissues(0.995±0.291)(P=0.021). 3. Immunohistochemistry staining showed that88out of184(47.8%) HCCs werePin1positive, which located in cytoplasm and (or) nucleus.And the positive rate washigher than corresponding adjacent liver tissues (35.9%，66/184), with statisticallysignificant difference (P<0.001). The expression of Pin1protein increased with thedecrease of tumor differentiation level (P=0.001). The positive rate of DAPK1inHCC was31%(57/184), which located in cytoplsam, was significantly lower thancorresponding adjacent liver tissues (62.5%,115/184)(P<0.001).143out of184(77.7%) HCCs had abnormal expression pattern of β-catenin, including reducedmembranous expression, cytoplasmic overexpression and nuclear accumulation. Andthe rate was significantly higher than corresponding adjacent liver tissues(52.7%,97/184)(P=0.003). The abnormal expression of β-catenin was positive correlatedwith the diameters of tumor (P=0.034). The spearman rank correlation test showedthat the Pin1expression was negatively correlated with DAPK1(r=﹣0.462，P<0.001)， and positively correlated with β-catenin (r=0.202， P=0.006). Theexpression of DAPK1was negatively correlated with β-catenin(r=﹣0.255，P=0.001).4.Kaplan-Meier and Cox survival analysis showed that the expression of Pin1andDAPK1in HCC was related to the patients’ disease-free survival (P=0.017andP=0.012respectively), Pin1and DAPK1expression were the independent riskfactors for HCC patients’ disease-free survival (P=0.025和P=0.002).The β-cateninexpression in HCC was related to the patients’ overall survival (P=0.027), andβ-catenin expression was the independent risk factors for HCC patients’ overallsurvival (P=0.016).Conclusion:1. The positive expression of Pin1protein probably promote the occurrence andprogression of HCC.2. Pin1probably promote the occurrence and progression of HCC by activating theWnt/β-catenin pathway.3. DAPK1probably prevent the occurrence and development of HCC throughnegatively regulating Pin1.4. Detection of Pin1, DAPK1and β-catenin protein may help predict the risk ofrecurrence and metastasis in HCC patients.