Expression And Clinical Significance Of Negative Immune Checkpoint Regulator VISTA In Hepatocellular Carcinoma

?Objective?To investigate the expression v-domain Ig suppressor of T cell activation(VISTA)in the clinical samples of hepatocellular carcinoma(HCC)and its clinical significance.?Methods?1.Part I: Specimens of 338 hepatocellular carcinoma patients were collected for the study,which were surgically resected and diagnosed by pathologists in Fuzhou General Hospital of PLA from January 2006 to December 2012.338 cases were collected with complete clinical information and follow-up datas.while excluding cases of death caused by complications such as other tumors,external factors or severe post-operative infections.Samples from 338 cases of HCC were used as research subjects;tissues array containing tumor and adjacent normal tissue were prepared then;moreover,the immunohistochemical staining of VISTA was performed for observation and analysis the correlation between the expression of VISTA and the clinicopathological factors and the prognosis of HCC.2.Part II:To observe the expression of CD8 and Foxp3 in tumor microenvironment of HCC and its clinicopathological significance as well as prognosis in HCC,and further research was using to analyze the correlation between the expression of VISTA and CD8,Foxp3.3.Part ?:To observe the expressions of ZEB1 protein in tumor microenvironment of HCC and its clinicopathological significance as well as prognosis in HCC,and further research was using to analyze the correlation between the expression of VISTA.?Results?1.The positive rates of VISTA in 338 cases of HCC were 16.27%(55/338),100%(338/338)and 89.05%(301/338)for tumor cells,intratumoral lymphocytes and vascular endothelial cells,respectively.The expression level of VISTA in HCC tumor cells was higher than that in normal liver tissue.2.The expression level of VISTA was correlated with tumor size,vascular invasion,differential grade of the tumor,T stage,serum AFP levels(P<0.05),but no correlated with other characteristics of patients such as age,sex,the presence of intact capsule,infection of hepatitis B virus,portal vein invasion of HCC cells,number of tumors,distant metastasis,postoperative recurrence and the presence of liver cirrhosis(P>0.05).There was no statistical significance between the patients' clinicopathological features and the expression of VISTA in tumor cells(P>0.05).3.A 5-year retrospective analysis of 338 cases of HCC shown that the overall survival rate of VISTA low expression group was significantly higher than that of VISTA high expression group(P<0.05),while no significant difference of recurrence-free survival rate between these two groups(P>0.05).4.The positive expression rate of CD8 and Foxp3 in 338 cases of HCC was 97.63%(330/338)?88.16%(298/338)for tumor intratumoral lymphocytes respectively.The expression level of CD8 was correlated with the presence of intact capsule,tumor size,vascular invasion,differential grade of the tumor,T stage,(P<0.05).The expression level of Foxp3 was correlated with vascular invasion,portal vein invasion of HCC cells,postoperative recurrence and serum AFP levels(P<0.05).5.In 338 cases of HCC shown that the 5-year survival rate of Foxp3 high expression group was significantly lower than that of Foxp3 low expression group(P=0.0005);CD8 low expression group was significantly lower than that of CD8 high expression group(P=0.0037),indicating that VISTA low expression group and CD8 high expression group showed good prognosis,VISTA high expression group and CD8 low expression group showed significantly poorer prognosis.when VISTA and Foxp3 were both negative at the same time,the patients had good prognosis.Low expression of VISTA and Foxp3,the high expression level of CD8 showed significantly good prognosis.High expression of VISTA and low expression of CD8,no matter how Foxp3 is expressed,the patients had poorer prognosis.6.Multivariate analysis of 338 HCC cases revealed that differential grade of the tumor,vascular invasion,portal vein invasion of HCC cells,high expression of VISTA and Foxp3 were independent risk factors for death.7.The positive expression rate of VISTA in 338 cases of HCC was 24.85%(84/338),The positive expression rate of the corresponding normal liver tissue was 0.59%(2/338).The expression level of ZEB1 was correlated with age,vascular invasion,infection of hepatitis B virus,T stage,serum AFP levelsportal(P<0.05).8.In 338 cases of HCC shown that the 5-year survival rate of ZEB1 low expression group was significantly higher than that of ZEB1 high expression group(P<0.05),while no significant difference of recurrence-free survival rate between these two groups(P>0.05).9.There was a positive correlation between VISTA protein and the expression of ZEB1 protein(P<0.05).?Conclusions?The expression of VISTA in HCC was predominantly located in intratumoral lymphocytes,There was no statistical significance between the patients' clinicopathological features and the low expression rate of VISTA in tumor cells.The expression of VISTA,CD8,and Foxp3 in TILs and the expression of ZEB1 in HCC tissues were correlated with multiple clinicopathological characteristics;In HCC intermediate lymphocytes,high expression of VISTA?Foxp3 and ZEB1,low expression of CD8 were correlated with tumor invasion and poor prognosis.High expression of VISTA and low expression of CD8,the patients had poorer prognosis.Low expression of VISTA and Foxp3,the high expression level of CD8 showed significantly good prognosis.The expression might be contribute to the prognostic judgment.There was a positive correlation between VISTA protein and the expression of ZEB1 protein.