B7-H4 is Predictive of Poor Prognosis in Patients with Gastric Cancer

Expression of Immune Checkpoints in Malignant Tumors: Therapy Targets and Biomarkers for the Gastric Cancer Prognosis

To increase the effectiveness of anticancer therapy based on immune checkpoint (IC) inhibition, some ICs are being investigated in addition to those used in clinic. We reviewed data on the relationship between PD-L1, B7-H3, B7-H4, IDO1, Galectin-3 and -9, CEACAM1, CD155, Siglec-15 and ADAM17 expression with cancer development in complex with the results of clinical trials on their inhibition. Increased expression of the most studied ICs—PD-L1, B7-H3, and B7-H4—is associated with poor survival; their inhibition is clinically significant. Expression of IDO1, CD155, and ADAM17 is also associated with poor survival, including gastric cancer (GC). The available data indicate that CD155 and ADAM17 are promising targets for immune therapy. However, the clinical trials of anti-IDO1 antibodies have been unsatisfactory. Expression of Galectin-3 and -9, CEACAM1 and Siglec-15 demonstrates a contradictory relationship with patient survival. The lack of satisfactory results of these IC inhibitor clinical trials additionally indicates the complex nature of their functioning. In conclusion, in many cases it is important to analyze the expression of other participants of the immune response besides target IC. The PD-L1, B7-H3, B7-H4, IDO1 and ADAM17 may be considered as candidates for prognosis markers for GC patient survival.

Association of Soluble B7-H4 and Circulating Tumor Cells in Blood of Advanced Epithelial Ovarian Cancer Patients

Introduction

Epithelial ovarian cancer (EOC) is the deadliest gynecologic malignancy worldwide. Reliable predictive biomarkers are urgently needed to estimate the risk of relapse and to improve treatment management. Soluble immune-checkpoints in EOC are promising molecules serving as prognostic biomarkers accessible via liquid biopsy. We thus, aimed at elucidating the role of sB7-H4 in EOC.

Material and Methods

We analyzed soluble serum B7-H4 (sB7-H4) using ELISA and circulating tumor cells (CTCs) in blood applying the AdnaTest OvarianCancer in 85 patients suffering from advanced EOC. Findings were correlated with clinical parameters as well as survival data.

Results

sB7-H4 was detectable in 14.1% patients, CTCs in 32.9% patients and simultaneous presence of CTCs and sB7-H4 was found in 7% patients, respectively. Although no association between sB7-H4 and CTC could be documented, each of them served as independent predictive factors for overall survival (OS).

Conclusion

sB7-H4 and CTCs are independent prognostic biomarkers for impaired survival in EOC. As they are easily accessible via liquid biopsy, they may be of potential benefit for the prediction of therapy response and survival for EOC patients.

The Positive and Negative Immunoregulatory Role of B7 Family: Promising Novel Targets in Gastric Cancer Treatment

Gastric cancer (GC), with a heterogeneous nature, is the third leading cause of death worldwide. Over the past few decades, stable reductions in the incidence of GC have been observed. However, due to the poor response to common treatments and late diagnosis, this cancer is still considered one of the lethal cancers. Emerging methods such as immunotherapy with immune checkpoint inhibitors (ICIs) have transformed the landscape of treatment for GC patients. There are presently eleven known members of the B7 family as immune checkpoint molecules: B7-1 (CD80), B7-2 (CD86), B7-H1 (PD-L1, CD274), B7-DC (PDCD1LG2, PD-L2, CD273), B7-H2 (B7RP1, ICOS-L, CD275), B7-H3 (CD276), B7-H4 (B7x, B7S1, Vtcn1), B7-H5 (VISTA, Gi24, DD1α, Dies1 SISP1), B7-H6 (NCR3LG1), B7-H7 (HHLA2), and Ig-like domain-containing receptor 2 (ILDR2). Interaction of the B7 family of immune-regulatory ligands with the corresponding receptors resulted in the induction and inhibition of T cell responses by sending co-stimulatory and co-inhibitory signals, respectively. Manipulation of the signals provided by the B7 family has significant potential in the management of GC.

The Regulatory Cross-Talk between microRNAs and Novel Members of the B7 Family in Human Diseases: A Scoping Review

The members of the B7 family, as immune checkpoint molecules, can substantially regulate immune responses. Since microRNAs (miRs) can regulate gene expression post-transcriptionally, we conducted a scoping review to summarize and discuss the regulatory cross-talk between miRs and new B7 family immune checkpoint molecules, i.e., B7-H3, B7-H4, B7-H5, butyrophilin like 2 (BTNL2), B7-H6, B7-H7, and immunoglobulin like domain containing receptor 2 (ILDR2). The current study was performed using a six-stage methodology structure and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. PubMed, Embase, Scopus, Cochrane, ProQuest, and Google Scholar were systematically searched to obtain the relevant records to 5 November 2020. Two authors independently reviewed the obtained records and extracted the desired data. After quantitative and qualitative analyses, we used bioinformatics approaches to extend our knowledge about the regulatory cross-talk between miRs and the abovementioned B7 family members. Twenty-seven articles were identified that fulfilled the inclusion criteria. Studies with different designs reported gene–miR regulatory axes in various cancer and non-cancer diseases. The regulatory cross-talk between the aforementioned B7 family molecules and miRs might provide valuable insights into the pathogenesis of various human diseases.

Combined detection of CA19-9 and B7-H4 in the diagnosis and prognosis of pancreatic cancer

BACKGROUND

There were no specific indicators for the early detection of pancreatic cancer.

OBJECTIVE

To analyze the diagnostic and prognostic value of CA19-9 plus B7-H4 detection in preoperative serum or surgical tissues of patients with pancreatic cancer.

METHODS

One hundred and eighty-eight patients with pancreatic cancer and 25 controls were recruited. Their preoperative serum CA19-9 level was detected chemiluminescently, and B7-H4 expression in pancreatic cancer tissues was assessed immunohistochemically. The diagnostic and prognostic utility of detecting CA19-9, B7-H4 and their combination was evaluated.

RESULTS

CA19-9 and B7-H4 levels were significantly upregulated in patients with pancreatic cancer compared with those in controls. The diagnostic value of combined CA19-9 plus B7-H4 detection was markedly better than that achieved from their separate detection analyzed with receiver operating characteristic curve. Sensitivity and specificity of the combined detection in the pancreatic cancer group was significantly increased compared with single detection. B7-H4 detection showed better prognostic value than detection of CA19-9. However, CA19-9 had high sensitivity and low specificity, while B7-H4 showed the opposite. The sensitivity of the combined prognosis was not significantly different to B7-H4 alone.

CONCLUSION

The combined detection of CA19-9 and B7-H4 could become a new method for the clinical diagnosis and prognosis of pancreatic cancer.

Comprehensive understanding of B7 family in gastric cancer: expression profile, association with clinicopathological parameters and downstream targets

Objectives: B7 family members were identified as co-stimulators or co-inhibitors of the immune response and played important roles in cancer immunotherapy; however, their dysregulation in gastric cancer is still unclear.

Methods: Data were obtained from TCGA and GTEX database. B7 mutations, association with DNA methylation and affected proteins were analyzed in cBioportal. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and Gene Ontology (GO) project was studied by DAVID to find the downstream signaling pathway and important metabolic process, respectively. Protein-protein interaction network was analyzed in STRING and Cytoscape. A total of 160 paired specimens in tissue microarray from patients with gastric cancer were used to detect the expression levels of seven B7 family members via immunohistochemical analysis.

Results: Bioinformatics studies revealed dysregulation of B7 members in gastric cancer. Gene and protein alteration were found in B7 family members. Furthermore, DNA methylation and gene alteration may be both involved in B7 member dysregulation in gastric cancer. Importantly, the high expression of B7-H6 is associated with good overall patient survival. B7 family members primarily affect the EGFR tyrosine kinase inhibitor resistance signaling pathway in gastric cancer and TP53 may be an important target of the family. The low expression of B7-1 and high expression of B7-H3 and B7-H7 were validated by IHC staining.

Conclusions: Our results provide insight into B7 family member expression in gastric cancer and stress their importance in stomach tumorigenesis, which may be beneficial for designing future cancer treatments.

Comprehensive molecular profiling of the B7 family in gastrointestinal cancer

OBJECTIVES

B7 family has been identified as co-stimulatory or co-inhibitory molecules on T-cell response and plays an important role in tumour mortality and malignancy. In this study, the expression pattern of B7 family in gastrointestinal (GI) cancer was examined. Its upstream regulating mechanism, downstream targets and association with clinical parameters were also studied.

MATERIALS AND METHODS

The expression level of B7 members was analysed by FIREHOUSE. The gene mutation, DNA methylation, association with clinical parameters and downstream network of B7 members were analysed in cBioportal. The mutation frequency was analysed by Catalogue of Somatic Mutations in Cancer (COSMIC) analysis. The phylogenetic tree was constructed in MEGA7. The interaction protein domain analysis was performed by Pfam 31.0.

RESULTS

Differential expression of B7 family molecules was detected in different kinds of GI cancer. High-frequency gene alteration was found in tumour samples. There was negative correlation of promoter methylation and mRNA expression of B7 family members in tumour samples, suggesting the epigenetic basis of B7 family gene deregulation in GI cancer. The overexpression of B7-H1 in pancreatic cancer, B7-H5 in oesophageal cancer and B7-H6 in liver cancer were significantly associated with worse overall survival. Finally, by network analysis, we identified some potential interacting proteins for B7-1/2 and B7-H1/DC.

CONCLUSIONS

Overall, our study suggested that B7 member deregulation was strongly involved in GI cancer tumorigenesis.

New B7 Family Checkpoints in Human Cancers

T cells are the main effector cells in immune response against tumors. The activation of T cells is regulated by the innate immune system through positive and negative costimulatory molecules. Targeting immune checkpoint regulators such as programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) and CTL antigen 4 (CTLA-4) has achieved notable benefit in a variety of cancers, which leads to multiple clinical trials with antibodies targeting the other related B7/CD28 family members. Recently, five new B7 family ligands, B7-H3, B7-H4, B7-H5, B7-H6, and B7-H7, were identified. Here we review recent understanding of new B7 family checkpoint molecules as they have come to the front of cancer research with the concept that tumor cells exploit them to escape immune surveillance. The aim of this article is to address the structure and expression of the new B7 family molecules as well as their roles in controlling and suppressing immune responses of T cells as well as NK cells. We also discuss clinical significance and contribution of these checkpoint expressions in human cancers. Mol Cancer Ther; 16(7); 1203-11. ©2017 AACR.

Prognostic role of B7-H4 in patients with non-small cell lung cancer: A meta-analysis

B7 homolog 4 (B7-H4) has been recently reported to be a prognostic marker in non-small cell lung cancer (NSCLC) in some studies. However, the results remained conflicting. Thus, we aimed to comprehensively assess the association between B7-H4 expression and prognosis of NSCLC patients by performing a meta-analysis. Relevant publications were thoroughly searched of PubMed, Embase, Web of Science and China National Knowledge Infrastructure (CNKI). The pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were applied to evaluate the effects. A total of 9 studies comprising 1444 patients were included in this meta-analysis. B7-H4 overexpression was associated with presence of lymph node metastasis (OR=3.59, 95%CI=2.39-5.38, p<0.001; fixed effect), advanced TNM stage (OR=2.36, 95%CI=1.2-4.67, p=0.013; random effect), and poor differentiation (OR=2.11, 95%CI=1.12-3.99, p=0.021; fixed effect). However, B7-H4 had no significant correlation with gender, age or histology in NSCLC. Furthermore, in a fixed effects model, the results indicated that B7-H4 overexpression was significantly associated with poor OS (HR=2.03, 95%CI=1.41-2.92, p<0.001). This meta-analysis demonstrated that high B7-H4 expression is an unfavorable prognostic factor in NSCLC. Because few studies were included for meta-analysis and almost all included studies were performed on Chinese patients, therefore; large scale prospective studies are needed to verify our results.

B7-Homolog 4 Promotes Epithelial-Mesenchymal Transition and Invasion of Bladder Cancer Cells via Activation of Nuclear Factor-κB

B7-homolog 4 (B7-H4), a member of the B7 family of costimulatory molecules, has been reported to be upregulated in urothelial cell carcinoma. This study was conducted to explore the biological role of B7-H4 in the aggressiveness of bladder cancer and the associated molecular mechanism. We found that the mRNA and protein levels of B7-H4 were significantly greater in bladder cancer cell lines than in SV-HUC-1 (normal human urothelial cells). Overexpression of B7-H4 significantly promoted bladder cancer cell migration and invasion, whereas knockdown of B7-H4 exerted an opposite effect. However, the growth of bladder cancer cells was not altered by B7-H4 overexpression or knockdown. Overexpression of B7-H4 promoted epithelial–mesenchymal transition (EMT), as evidenced by decreased E-cadherin and increased vimentin expression. The EMT inducers Twist1 and Snail were upregulated by B7-H4 overexpression and downregulated by B7-H4 silencing. Mechanistically, overexpression of B7-H4 induced the activation of NF-κB signaling. Pharmacological inhibition of NF-κB partially prevented B7-H4-mediated bladder cancer cell invasion. Taken together, B7-H4/NF-κB signaling is involved in the EMT and invasion of bladder cancer cells and represents a new candidate target for the treatment of bladder cancer.

Immunosuppressive Effect of B7-H4 Pathway in a Murine Systemic Lupus Erythematosus Model

B7-H4, one of the co-stimulatory molecules of the B7 family, has been shown to play an important role in negatively regulating the adaptive immune response by inhibiting the proliferation, activation, and cytokine production of T cells. In this study, we investigate the role of B7-H4 in development of systemic lupus erythematosus (SLE). We investigated a murine model of SLE using transfer of bone marrow-derived dendritic cells (BMDCs) that were incubated with activated syngeneic lymphocyte-derived DNA. The recipient mouse produced anti-ds-DNA antibodies as well as displayed splenomegaly and lymphadenopathy as shown by significantly increased weights, and the kidneys showed lupus-like pathological changes include urine protein and glomerulonephritis with hyperplasia in glomeruli and increased mesangial cells and vasculitis with perivascular cell infiltration, glomerular deposition of IgG and complement C3. We showed that B7-H4 deficiency in BMDCs could cause greater production of anti-ds-DNA antibodies in transferred mice, and the lymph tissue swelling and the kidney lesions were also exacerbated with B7-H4 deficiency. Treatment with a B7-H4 antagonist antibody also aggravated the lupus model. Conversely, B7-H4 Ig alleviated the lupus manifestations. Therefore, we conclude that B7-H4 is a negative check point for the development of SLE in this murine model. These results suggest that this approach may have a clinical potential in treating human SLE.

B7-H4 is a prognostic biomarker for poor survival in patients with pancreatic cancer

B7-H4 belongs to the immune costimulatory B7 family and is thought to negatively regulate T-cell-mediated immunity, and may contribute an important role in tumor immune evasion. Although the expression of B7-H4 has been observed in human pancreatic cancer, the prognostic significance of this expression is poorly understood. This present study explored the prognostic value of B7-H4 in pancreatic cancer. Patients with pancreatic cancer and healthy controls were recruited at the Second Affiliated Hospital to Zhejiang University from January 2011 to December 2014. Expression of B7-H4 was assessed by immunohistochemistry. Immunohistochemical analysis indicated that B7-H4 was expressed in 100% (188/188) of the pancreatic cancer tumor tissue samples, while only in 68% (17/25) of normal pancreatic tissue samples. Furthermore, the expression levels of B7-H4 in pancreatic cancer patients were significantly higher than in controls (P<.01). A significant difference in B7-H4 expression was observed between patients with late tumor-node-metastasis (TNM) stage (III and IV) and early TNM stage (I and II) (P<.01). The expression of B7-H4 was associated with distant metastasis (P<.01) and differentiation (P<.01). In addition, B7-H4 expression (P<.01), distant metastasis (P<.01), TNM stage (P<.01), differentiation (P<.01) and chemotherapy treatment (P<.05) were indicators of poor overall survival time. Multivariate survival analysis indicated that B7-H4 expression, distant metastasis, and chemotherapy treatment (P<.05) were independent prognostic indicators of poor overall survival. In conclusion, B7-H4 is highly expressed in pancreatic cancer, and is an independent predictor of poor prognosis in patients with pancreatic cancer. B7-H4 may represent an immunotherapeutic target in pancreatic cancer.