Liju Zong

Analysis of the immune checkpoint V-domain Ig-containing suppressor of T-cell activation (VISTA) in endometrial cancer

V-domain Ig-containing suppressor of T-cell activation (VISTA) is a novel immune checkpoint protein and a potential immunotherapeutic target. However, its expression in endometrial cancer has not been clearly defined. This study aimed to investigate VISTA expression and determine its associations with clinicopathological features, molecular subtypes, programmed cell death-ligand 1 (PD-L1) expression, CD8+ T-cell count, and survival in a cohort of 839 patients with endometrial cancer. Using direct sequencing of the polymerase epsilon (POLE) exonuclease domain and immunohistochemistry for mismatch repair (MMR) proteins and p53, we stratified endometrial cancers into four molecular subtypes: POLE ultramutated, MMR-deficient, p53-mutant, and nonspecific molecular profile (NSMP). PD-L1, CD8, and VISTA were detected via immunohistochemistry. VISTA was expressed in the immune cells of 76.6% (643/839) of the samples and in the tumor cells of 6.8% (57/839). VISTA positivity in the immune cells was frequent in tumors staged I-III, those with positive PD-L1 or high CD8+ T-cell density, and those representing POLE ultramutated and MMR-deficient subtypes. Furthermore, VISTA positivity in tumor cells was more frequent in clear cell carcinoma samples. VISTA in immune cells was associated with improved survival in the entire cohort as well as in the endometrioid histology, stage I, PD-L1-negative, MMR-deficient, MMR-proficient, and high and low number of CD8+ T-cell-infiltrated tumor subgroups. VISTA in immune cells was a prognostic factor overall, as well as in patients with endometrioid histology, independent of molecular subtype or CD8+ T-cell density. The data produced by this study, which was the largest to focus on VISTA expression in patients with endometrial cancer to date, suggest that VISTA is a predictor of improved survival.

VISTA expression is associated with a favorable prognosis in patients with high-grade serous ovarian cancer

AbstractBlockading programmed death ligand 1 (PD-L1) shows promising results in patients with some cancers, but not in those with ovarian cancer. V-domain Ig suppressor of T cell activation (VISTA) is a recently discovered immune checkpoint protein that suppresses T cell activation. This study aimed to investigate the expression and clinical significance of VISTA in ovarian cancer as well as its relationship with PD-L1. VISTA and PD-L1 levels in 146 ovarian cancer samples were assessed using immunohistochemistry. We investigated the association between VISTA and other clinicopathological variables, including survival. The associations between the VISTA-encoding C10orf54 gene, other immune checkpoints, and survival were analyzed. VISTA was detected in 51.4% of all samples and 46.6% of PD-L1-negative samples; it was expressed in 28.8%, 35.6%, and 4.1% of tumor cells (TCs), immune cells (ICs), and endothelial cells, respectively. Furthermore, VISTA expression was associated with pathologic type and PD-L1 expression. Moreover, VISTA expression in TCs, but not in ICs, was associated with prolonged progression-free and overall survival in patients with high-grade serous ovarian cancer. The expression of C10orf54 mRNA was associated with prolonged overall survival and immune escape-modulating genes. These results showed that VISTA expression in ovarian tumor cells was associated with a favorable prognosis in patients with high-grade serous ovarian cancer; however, additional studies are required to better understand the expression and role of VISTA in ovarian cancer.

Expression of B7 family checkpoint proteins in cervical cancer

The role of programmed cell death-ligand 1 (PD-L1) in cervical cancer has been widely investigated; however, the influences of other inhibitory B7 family members are poorly understood. We investigated the expression of PD-L1, B7 homolog 3 (B7-H3), B7-H4, and V-domain Ig suppressor of T-cell activation (VISTA) and their association with the clinicopathological features and outcomes of a large cohort of 673 patients with squamous cell carcinoma or adenocarcinoma of the uterine cervix. The positivity rates for PD-L1 (combined positive score ≥1), B7-H3 in tumor cells (TCs), B7-H4 (exclusively in TCs), VISTA in immune cells (ICs), and VISTA in TCs were 57.9%, 62.8%, 44.8%, 92.6%, and 4.8%, respectively, in 606 primary cervical cancer samples. Co-expression of PD-L1 with B7-H3 in TCs and with B7-H4 and VISTA in ICs was observed in 38.8%, 25.4%, and 57.9% of samples, respectively. B7-H3 in TCs and B7-H4 and VISTA in ICs were observed in 58.1%, 46.6%, and 83.1% of PD-L1-negative samples, respectively. These proteins were observed more frequently in squamous cell carcinomas and in moderately to poorly differentiated carcinomas. VISTA (in ICs) and B7-H4 were more frequent in primary tumors than in recurrent counterparts and correlated with improved survival; in contrast, B7-H3 positivity in TCs was less frequent in primary tumors and correlated with short disease-specific survival. Co-expression of B7-H4 and VISTA in ICs was an independent predictor of favorable outcomes overall and among patients with PD-L1-negative tumors. These data indicate that B7 family proteins exhibit differing expression patterns, distributions, and prognostic implications in cervical cancer. Furthermore, the co-expression of PD-L1 with other checkpoint proteins suggests that PD-1/PD-L1 blockade combined with modulating other immune checkpoints may present a novel therapeutic approach for cervical cancer. Future studies are needed to validate prognostic values of B7 family proteins and explore their biological roles in this malignancy.

B7‐H4 Expression in Precancerous Lesions of the Uterine Cervix

Over 10% of patients diagnosed with cervical intraepithelial neoplasia (CIN) have no lesions detected in their cervical conization specimens. The purpose of this study was to determine the factors related to the absence of such lesions. We particularly sought to investigate whether the expression of B7‐H4 in precancerous lesions and cancer of the uterine cervix plays a role in the presence or absence of residual lesions in conization specimens and whether this protein is associated with T cells (i.e., Foxp3+ regulatory T cells, CD4+, and CD8+) and interferon‐γ production. Of the 807 patients with CIN treated by conization, 104 (12.9%) had no lesions in their conization specimens. Seventy‐five of these patients were deemed the study group and were matched with 75 patients who did have CIN detected in their conization specimens (the control group). Immunohistochemistry and immunofluorescence staining were used to detect B7‐H4, Foxp3, CD4, CD8, and interferon‐γ in the 75 pairs of specimens obtained via biopsy; 20 samples were found to have chronic cervicitis, and another 20 had squamous cell carcinoma of the cervix. Menopause, the absence of human papillomavirus, low‐grade histological findings, and a diagnosis of CIN1 and CIN2 on biopsy correlated with a low probability of lesions on conization specimens. B7‐H4 expression was detected in 11.1% of CIN2, 46.6% of CIN3, and 70% of cervical cancer samples, but not in tissues representing chronic cervicitis or CIN1. B7‐H4 expression was associated with the presence of lesions on conization specimens, increased regulatory T cells, decreased CD8+ T cells, and lower interferon‐γ production. These data suggest that close follow‐up and thorough reevaluation should be considered for patients diagnosed with CIN2 who are negative for B7‐H4 expression on biopsy before proceeding with cervical conization.