Analysis of B7-H4 Expression Across Salivary Gland Carcinomas Reveals Adenoid Cystic Carcinoma-Specific Prognostic Relevance.

B7-H4 (VTCN1), a member of the B7 family, is overexpressed in several types of cancer. Here we investigated the pattern of expression of B7-H4 in salivary gland carcinomas (SGC) and assessed its potential as a prognostic marker and therapeutic target. Immunohistochemistry (IHC) analyses were performed in a cohort of 340 patient tumors, composed of 124 adenoid cystic carcinomas (ACC), 107 salivary duct carcinomas (SDC), 64 acinic cell carcinomas, 36 mucoepidermoid carcinomas (MEC), 9 secretory carcinomas (SC), as well as 20 normal salivary glands (controls). B7-H4 expression was scored and categorized into negative (<5% expression of any intensity), low (5%-70% expression of any intensity or >70% with weak intensity), or high (>70% moderate or strong diffuse intensity). The associations between B7-H4 expression and clinicopathologic characteristics, as well as overall survival, were assessed. Among all tumors, B7-H4 expression was more prevalent in ACC (94%) compared with those of SC (67%), MEC (44%), SDC (32%), and acinic cell carcinomas (0%). Normal salivary gland tissue did not express B7-H4. High expression of B7-H4 was found exclusively in ACC (27%), SDC (11%), and MEC (8%). In SDC, B7-H4 expression was associated with female gender (P = .002) and lack of androgen receptor expression (P = .012). In ACC, B7-H4 expression was significantly associated with solid histology (P < .0001) and minor salivary gland primary (P = .02). High B7-H4 expression was associated with a poorer prognosis in ACC, regardless of clinical stage and histologic subtype. B7-H4 expression was not prognostic in the non-ACC SGC evaluated. Our comparative study revealed distinct patterns of B7-H4 expression according to SGC histology, which has potential therapeutic implications. B7-H4 expression was particularly high in solid ACC and was an independent prognostic marker in this disease but not in the other SGC assessed.

Altered Levels of Negative Costimulatory Molecule V-Set Domain-Containing T-Cell Activation Inhibitor-1 (VTCN1) and Metalloprotease Nardilysin (NRD1) are Associated with Generalized Active Vitiligo.

BACKGROUND: Vitiligo is characterized by depigmented macules on the skin caused due to autoimmune destruction of melanocytes. V-set domain-containing T-cell activation inhibitor-1 (VTCN1) is a negative costimulatory molecule that plays a vital role in suppressing autoimmunity and tuning immune response. Nardilysin (NRD1), a metalloproteinase, cleaves membrane-tethered VTCN1 resulting in the shedding of soluble-VTCN1 (sVTCN1). However, the role of VTCN1 and NRD1 in vitiligo pathogenesis is unexplored. OBJECTIVES AND METHODS: This study was aimed to (i) Investigate the association of VTCN1 intronic polymorphisms (rs10923223 T/C and rs12046117 C/T) with vitiligo susceptibility in Gujarat population by using Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP) (ii) Estimate VTCN1 & NRD1 transcript levels from peripheral blood mononuclear cells (PBMCs) and skin samples of vitiligo patients by real-time PCR, (iii) Estimate sVTCN1 and NRD1 protein levels from plasma by ELISA and (iv) Estimate VTCN1 protein levels in the skin samples of vitiligo patients by immunofluorescence. RESULTS: The analysis revealed increased VTCN1 and NRD1 transcript levels in the skin (p = .039, p = .021 respectively), increased sVTCN1 and NRD1 levels (p = .026, p = .015 respectively) in the plasma, and decreased VTCN1 protein levels (p = .0002) in the skin of vitiligo patients as compared to healthy controls. The genetic analysis revealed no significant association of VTCN1 intronic polymorphisms rs10923223 T/C and rs12046117 C/T with vitiligo susceptibility in Gujarat population (p = .359, p = .937, respectively). CONCLUSIONS: The present study revealed altered VTCN1 and NRD1 expressions in the blood and skin of vitiligo patients, suggesting their potential role in the development and progression of Vitiligo.

The Immune Regulator VTCN1 Gene Polymorphisms and Its Impact on Susceptibility to Breast Cancer.

BACKGROUND: VTCN1, a T-cell regulator, belongs to the immunoglobulin superfamily. It is more highly expressed in tumor tissues than in normal tissues, which suggests that it could serve as a tumor-related agent. We hypothesize the gene variants for this coinhibitory molecule may be associated with the risk of breast cancer, given such gene polymorphisms could affect its related gene expression. METHODS: Genotypes of the VTCN1 gene variants (rs10754339, rs10801935, and rs3738414) were analyzed in 566 patients with breast cancer and 400 age-frequency-matched controls. RESULTS: Compared with the major allele, the minor alleles of rs10754339, rs10801935, and rs3738414 did modulate the risk of breast cancer with ORs (95% CI) of 1.42 (1.07-1.89), 1.39 (1.10-1.77), and 0.81 (0.67-0.99), respectively. Those with the rs10754339 genotype AG and rs10801935 AC genotype had significantly increased risks when compared with their major genotypes. However, in rs3738414, the AA genotype had a marginally significant decreased risk compared with its wild genotype. In the haplotype-based analysis, the GCG allele was associated with significantly increased risk (OR: 1.56, 95% CI: 1.09-2.22) based on the AAG reference. Further analyses of the haplotype pairs showed GCG carriers had a significantly increased risk. CONCLUSIONS: In this study, the VTCN1 genetic variants (rs10754339, rs10801935, and rs3738414) indicate they could be connected with the risk of breast cancer, which in turn provides indirect evidence that T-cell immunity could be involved in the development of breast cancer.

A SOX9-B7x axis safeguards dedifferentiated tumor cells from immune surveillance to drive breast cancer progression.

How dedifferentiated stem-like tumor cells evade immunosurveillance remains poorly understood. We show that the lineage-plasticity regulator SOX9, which is upregulated in dedifferentiated tumor cells, limits the number of infiltrating T lymphocytes in premalignant lesions of mouse basal-like breast cancer. SOX9-mediated immunosuppression is required for the progression of in situ tumors to invasive carcinoma. SOX9 induces the expression of immune checkpoint B7x/B7-H4 through STAT3 activation and direct transcriptional regulation. B7x is upregulated in dedifferentiated tumor cells and protects them from immunosurveillance. B7x also protects mammary gland regeneration in immunocompetent mice. In advanced tumors, B7x targeting inhibits tumor growth and overcomes resistance to anti-PD-L1 immunotherapy. In human breast cancer, SOX9 and B7x expression are correlated and associated with reduced CD8+ T cell infiltration. This study, using mouse models, cell lines, and patient samples, identifies a dedifferentiation-associated immunosuppression mechanism and demonstrates the therapeutic potential of targeting the SOX9-B7x pathway in basal-like breast cancer.

The immune checkpoint molecule, VTCN1/B7-H4, guides differentiation and suppresses proinflammatory responses and MHC class I expression in an embryonic stem cell-derived model of human trophoblast.

The placenta acts as a protective barrier to pathogens and other harmful substances present in the maternal circulation throughout pregnancy. Disruption of placental development can lead to complications of pregnancy such as preeclampsia, intrauterine growth retardation and preterm birth. In previous work, we have shown that expression of the immune checkpoint regulator, B7-H4/VTCN1, is increased upon differentiation of human embryonic stem cells (hESC) to an in vitro model of primitive trophoblast (TB), that VTCN1/B7-H4 is expressed in first trimester but not term human placenta and that primitive trophoblast may be uniquely susceptible to certain pathogens. Here we report on the role of VTCN1 in trophoblast lineage development and anti-viral responses and the effects of changes in these processes on major histocompatibility complex (MHC) class I expression and peripheral NK cell phenotypes.

V-set domain containing T-cell activation inhibitor-1 (VTCN1): A potential target for the treatment of autoimmune diseases.

Autoimmunity eventuates when the immune system attacks self-molecules as a result of the breakdown in immune tolerance. Targeting autoimmune diseases via immunomodulation has become an essential strategy in today's era. A B7 superfamily member immune checkpoint, the V-set domain containing T-cell activation inhibitor-1 (VTCN1), also known as B7-H4, B7S1, and B7x, is involved in negatively regulating T-cell activation. VTCN1 transcript has been reported in various lymphoid and non-lymphoid tissues, but its protein expression is restricted, indicating its translational regulation. Dysregulation of VTCN1 has resulted in the exacerbation of various autoimmune diseases. Moreover, increased soluble form of VTCN1 in the patient's sera positively correlates with the disease progression and severity. The current review summarizes all the reports till date, unfolding the role of VTCN1 in various autoimmune diseases and its therapeutic potential.

Profiling of inhibitory immune checkpoints in glioblastoma: Potential pathogenetic players.

Glioblastoma (GBM) represents the most frequent glial tumor, with almost 3 new cases per 100,000 people per year. Despite treatment, the prognosis for GBM patients remains extremely poor, with a median survival of 14.6 months, and a 5-year survival less than 5%. It is generally believed that GBM creates a highly immunosuppressive microenvironment, sustained by the expression of immune-regulatory factors, including inhibitory immune checkpoints, on both infiltrating cells and tumor cells. However, the trials assessing the efficacy of current immune checkpoint inhibitors in GBM are still disappointing. In the present study, the expression levels of several inhibitory immune checkpoints in GBM (CD276, VTCN1, CD47, PVR, TNFRSF14, CD200, LGALS9, NECTIN2 and CD48) were characterized in order to evaluate their potential as prognostic and eventually, therapeutic targets. Among the investigated immune checkpoints, TNFRSF14 and NECTIN2 were identified as the most promising targets in GBM. In particular, a higher TNFRSF14 expression was associated with worse overall survival and disease-free survival, and with a lower Th1 response.

Insulin-like growth factor-1 receptor induces immunosuppression in lung cancer by upregulating B7-H4 expression through the MEK/ERK signaling pathway.

The Insulin-like growth factor-1/Insulin-like growth factor-1 receptor (IGF1/IGF1R) axis contributes to immunosuppression during tumor progression; however, the underlying mechanism remains unclear. In the present study, we found that IGF1 stimulation or IGF1R overexpression (IGF1R-OE) could upregulate the expression of B7-H4, while IGF1R inhibition downregulated B7-H4 in both A549 and SPC-A-1 lung cancer cell lines. IGF1R-OE conferred the inhibition of CD8+ T cells by cancer cells in vitro, and induction of B7-H4 expression was mediated by the activation of the MEK/ERK1/2 signaling pathway. The in vitro findings were further confirmed in vivo using a Lewis lung cancer mouse model. IGF1R-OE promoted tumor growth and inhibited tumor infiltration by CD8+ T cells in the mouse model. However, this effect was suppressed when B7-H4 was knocked down in IGF1R-OE cells. Our findings suggest that IGF1R could induce immunosuppression in lung cancer by upregulating the expression of B7-H4 through the MEK/ERK pathway. B7-H4 may therefore be a potential therapeutic target for lung cancer immunotherapy.

B7x-from bench to bedside.

B7x is an immune checkpoint molecule which belongs to the B7 family of ligands which includes PD-L1, PD-L2, B7-H3 and HHLA2. B7x belongs to the Immunoglobulin superfamily and its protein structure is similar to other members with a N terminus peptide, IgV and IgC like extracellular domain with four cysteine residues. Its receptor is yet to be identified. B7x inhibits T cell proliferation and expansion by IL-2 dependent and non-IL-2 dependent pathways. Even though high levels of B7x mRNA can be detected in most tissues its protein expression is highly limited suggesting significant post translational control. In vivo data, show that B7x plays an important role in limiting autoimmunity in the peripheral tissues and fine-tuning autoimmune responses. B7x is highly expressed in various cancers and in prostate cancer its expression is corelated with poorer outcomes. Local production of IL-6 and IL-10 in various cancers promotes B7x expression and tumor immune evasion. B7x is especially expressed in PD-L1 negative tumors suggesting that this may be an important method of immune evasion in these tumors. Currently drug development, targeting B7x through various mechanisms including monoclonal antibodies and antibody drug conjugates are in development in cancers and increasing B7x expression with fusion proteins in autoimmune diseases is underway.

Gene signature driving invasive mucinous adenocarcinoma of the lung.

Though invasive mucinous adenocarcinoma of the lung (IMA) is pathologically distinctive, the molecular mechanism driving IMA is not well understood, which hampers efforts to identify therapeutic targets. Here, by analyzing gene expression profiles of human and mouse IMA, we identified a Mucinous Lung Tumor Signature of 143 genes, which was unexpectedly enriched in mucin-producing gastrointestinal, pancreatic, and breast cancers. The signature genes included transcription factors FOXA3, SPDEF, HNF4A, mucins MUC5AC, MUC5B, MUC3, and an inhibitory immune checkpoint VTCN1/B7-H4 (but not PD-L1/B7-H1). Importantly, induction of FOXA3 or SPDEF along with mutant KRAS in lung epithelium was sufficient to develop benign or malignant mucinous lung tumors, respectively, in transgenic mice. FOXA3 and SPDEF induced MUC5AC and MUC5B, while HNF4A induced MUC3 in human mucinous lung cancer cells harboring a KRAS mutation. ChIP-seq combined with CRISPR/Cas9 determined that upstream enhancer regions of the mucin genes MUC5AC and MUC5B, which were bound by SPDEF, were required for the expression of the mucin genes. Here, we report the molecular signature and gene regulatory network driving mucinous lung tumors.

[Effect of ShRNA targeting silencing of VTCN1 gene on nasopharyngeal carcinoma cells].

Objective:The aim of this study is to investigate the expression of VTCN1 in nasopharyngeal carcinoma cells and targeting silencing of VTCN1 gene by infected with lentiviral vector to inhibit the proliferation and invasion in nasopharyngeal carcinoma cells. Method:The VTCN1 expression level of different nasopharyngeal carcinoma cells was detected by RT-PCR and Western blotting, the cell lines of the most expression level were seleted to conduct the Subsequent experiments; The lentiviral vector of silenced VTCN1 was transfected into HNE2 cells with VTCN1 expression by lipofectamine 2000, and stable cell lines were screened. Then, the silencing efficiency was detect by RT-PCR and Western blotting; The proliferation and invasion abilities of nasopharyngeal carcinoma cells after VTCN1 gene silencing were detected by ckk-8 and Transwell invasion assay, respectively. The phosphorylation levels of JAK/STAT proteins in nasopharyngeal carcinoma cells with VTCN1 gene silencing were detected by Western blotting. Result:RT-PCR and Western blotting detected that stable transfection of VTCN1ShRNA into HNE2 cells resulted significantly declined expression of VTCN1 (P<0.05); The proliferation and invasion abilities of HNE2 cells were significantly decreased (P<0.05) and phosphorylation level of the JAK, STAT proteins were significantly decreased (P<0.05). Conclusion:VTCN1 ShRNA can effectively silence the expression of VTCN1, and significantly inhibits the proliferation and invasion of HNE2 cells. It may be related to down regulation of protein activity in JAK/STAT signaling pathway..

Effect of VTCN1 on progression and metastasis of ovarian carcinoma in vitro and vivo.

BACKGROUND AND PURPOSES: Through reducing immune response, VTCN1 could promote carcinoma indirectly. However, the direct effect of VTCN1 on carcinoma was not studied clearly, especially on ovarian carcinoma. In this paper, we verified the potential effect and mechanism of VTCN1 on ovarian carcinoma. METHODS: The influence of high or low VTCN1 expression on the viability of ovarian cancer was detected by CKK-8 and annexin V-PI kit. The orthotopicxenograft tumor model was performed to evaluate the effect of VTCN1 on the promotion of tumor in vivo. Western blot was used to verify the signaling pathways predicted by bioinformatics analysis. RESULTS: Low expression of VTCN1 could inhibit the viability and metastasis of ovarian carcinoma directly in vitro and vivo; Information analysis demonstrated that cell cycle and JAK2/STAT were involved in the regulation of VTCN1. The CDK2/4 and CDC25C expression and phosphorylation of JAK2/STAT had a direct relationship with the reduction of VTCN1. CONCLUSIONS: VTCN1 could affect the viability and metastasis of ovarian carcinoma by reducing the expression of CDK2/4 and CDC25C and phosphorylation of JAK2/STAT. It indicated that VTCN1 was a potential target for treating ovarian carcinoma.