Abstract
V-domain immunoglobulin suppressor of T cell activation (VISTA) is a novel negative immune checkpoint that belongs to the B7 family. VISTA is primarily expressed on hematopoietic cells and inhibits T cell proliferation and cytokine production. The blockade of VISTA has demonstrated promising results in certain murine tumor models. In the present study, an immunohistochemical analysis of VISTA expression on tumor cells, intratumoral immune cells and vascular endothelial cells was performed in a cohort of 65 patients with ovarian cancer (OC). The associations between VISTA expression and different clinicopathological characteristics were evaluated using Fisher's exact test, and the analysis of overall survival in different groups was performed by the construction of Kaplan-Meier curves. The results indicated that high expression of VISTA on tumor cells or ICs was significantly associated with advanced tumor stage and the presence of lymph node metastasis (LNM). However, the percentage of cases with high expression of VISTA on tumor cells (24.6%) was decreased compared with those with high expression on ICs (44.6%). There was no association between VISTA expression and the 5-year overall survival rate, and advanced-stage disease was the only independent predictor of poor prognosis based on multivariate Cox regression analysis. In general, VISTA expression increased with advanced disease stage and LNM, indicating that VISTA expression is involved in the progression of OC. More importantly, these data implicate VISTA as a candidate immunotherapeutic target in OC.