Expression of negative immune checkpoint regulator VISTA and its significance in the prognostic evaluation of liver transplantation for hepatocellular carcinoma

Objective To explore the expression and significance of v-domain Ig suppressor of T cell activation (VISTA) in the clinical samples of hepatocellular carcinoma (HCC). Methods Sixty-nine cases of HCC were recruited as research subjects. Tissue microarrays containing tumor and adjacent tissue were prepared. Immunohistochemical staining of VISTA was performed for analyzing the correlation between the expression of VISTA, its clinicopathological factors and the prognosis of HCC. Results The positive rates of VISTA were 8.70%(6/69), 100%(69/69) and 65.22%(45/69) for tumor cells, intratumoral lymphocytes and vascular endothelial cells respectively. The expression of VISTA of intratumoral lymphocytes in adjacent tissues was higher than that in tumor central area (P 0.05). No difference of statistical significance between clinicopathological features and the expression of VISTA in tumor cells (P<0.05). Kaplan-Meier survival curve analysis indicated that the overall survival and recurrence-free survival rates of VISTA low-expression group were markedly higher than those of VISTA high-expression group (P<0.05). Conclusions The expression of VISTA in HCC is predominantly concentrated in intratumoral lymphocytes. It is associated with tumor size. And an elevated expression of VISTA may be a potential marker of poor prognosis in HCC patients. VISTA is expected to be a new therapeutic target for HCC. Key words: Hepatocellular carcinoma; Liver transplantation; VISTA; Tissue microarray