The inhibitory role of b7-h4 in antitumor immunity: association with cancer progression and survival

Unlocking molecular mechanisms and identifying druggable targets in matched-paired brain metastasis of breast and lung cancers

Introduction

The incidence of brain metastases in cancer patients is increasing, with lung and breast cancer being the most common sources. Despite advancements in targeted therapies, the prognosis remains poor, highlighting the importance to investigate the underlying mechanisms in brain metastases. The aim of this study was to investigate the differences in the molecular mechanisms involved in brain metastasis of breast and lung cancers. In addition, we aimed to identify cancer lineage-specific druggable targets in the brain metastasis.

Methods

To that aim, a cohort of 44 FFPE tissue samples, including 22 breast cancer and 22 lung adenocarcinoma (LUAD) and their matched-paired brain metastases were collected. Targeted gene expression profiles of primary tumors were compared to their matched-paired brain metastases samples using nCounter PanCancer IO 360™ Panel of NanoString technologies. Pathway analysis was performed using gene set analysis (GSA) and gene set enrichment analysis (GSEA). The validation was performed by using Immunohistochemistry (IHC) to confirm the expression of immune checkpoint inhibitors.

Results

Our results revealed the significant upregulation of cancer-related genes in primary tumors compared to their matched-paired brain metastases (adj. p ≤ 0.05). We found that upregulated differentially expressed genes in breast cancer brain metastasis (BM-BC) and brain metastasis from lung adenocarcinoma (BM-LUAD) were associated with the metabolic stress pathway, particularly related to the glycolysis. Additionally, we found that the upregulated genes in BM-BC and BM-LUAD played roles in immune response regulation, tumor growth, and proliferation. Importantly, we identified high expression of the immune checkpoint VTCN1 in BM-BC, and VISTA, IDO1, NT5E, and HDAC3 in BM-LUAD. Validation using immunohistochemistry further supported these findings.

Conclusion

In conclusion, the findings highlight the significance of using matched-paired samples to identify cancer lineage-specific therapies that may improve brain metastasis patients outcomes.

Activity of low-molecular weight components of Larix sibirica antioxidant system under exposure to technogenic pollution

Changes in the antioxidant protection system of Larix sibirica Ledeb at different pollution levels caused by emissions from a large aluminum smelter (BrAS) have been studied. We revealed that the content of peroxide (H₂O₂) in the needles is a reliable marker of oxidative stress in the trees under pollution. The crucial role of non-enzymatic components, in particular, proline, phenolic compounds, ascorbic acid, glutathione, in reducing the level of free radicals in the needles cells was found. Proline concentration in the needles significantly rises with the increase in pollution levels from low to high. Under critical level pollution, it decreases by 40% compared to the background. The total content of ascorbic acid (ASC) in the needles of polluted trees varies slightly; however, there are significant changes in its various forms. With an increase in pollution to a high level, the content of the reduced form of ASC in the needles increases by 1.5-2.9 times compared to the background content. At a critical level of pollution, the total level of ascorbic acid and its reduced form falls, the content of the oxidized form reaches minimum values. The total content of phenolic compounds in the needles increased by 50-55%, concentration of flavonoids by 1.5-1.8 times, catechins by 1.9-2.5 times, proanthocyanidins by 45% compared to the background level under low, moderate, high pollution, whereas under critical pollution their content decreased. The absolute concentration of the reduced form glutathione in the needles falls by 1.9-3.0 times, the oxidized form increases by 1.5-2.0 times compared to the background. The ratio of reduced glutathione to oxidized glutathione decreased, especially during critical pollution. The data obtained show significant activation of Siberian larch biochemical protection at low, moderate and high levels of pollution by the aluminum smelter emissions. At a critical levels of contamination, a significant depletion of the pool of low-molecular antioxidants was observed.

Single-Cell Proteomics Analysis of Recurrent Low-Grade Serous Ovarian Carcinoma and Associated Brain Metastases

Between 2% and 6% of epithelial ovarian cancer (EOC) patients develop brain metastases (brain mets), which are incurable and invariably result in death. This poor outcome is associated with a lack of established guidelines for the detection and treatment of brain mets in EOC patients. In this study, we characterize an unusual case of low-grade serous ovarian carcinoma (LGSOC) that metastasized to the brain. Using a spatially oriented single-cell proteomics platform, we compared sequential biopsies of a primary tumor with a peritoneal recurrence and brain mets. We identified several targetable oncogenic pathways and immunosuppressive mechanisms that are amplified in the brain mets and could be involved in the progression of LGSOC to the brain. Furthermore, we were able to identify cell populations that are shared between the primary tumor and the brain mets, suggesting that cells that have a propensity for metastasis to the brain could be identified early during the course of disease. Taken together, our findings further a path for personalized therapeutic decisions in LGSOC.

B7-H4 expression is upregulated by PKCδ activation and contributes to PKCδ-induced cell motility in colorectal cancer

Introduction

B7-H4 is overexpressed in colorectal cancer (CRC) and plays an important role in tumor growth and immunosuppression. However, the exact mechanism that regulates B7-H4 expression remains largely unknown. Here, we investigated whether protein kinase C δ (PKCδ) regulates the expression of B7-H4 in CRC.

Methods

By using immunohistochemical (IHC) and immunofluorescence (IF) staining, we analyzed the expression of B7-H4 and phospho-PKCδ (p-PKCδ) in 225 colorectal tumor samples and determined the clinical significance of the expression patterns. In vitro experiments were performed with the CRC cell lines HCT116 and SW620 to detect the effect of PKCδ activation on B7-H4 expression, and xenograft-bearing mice were treated with rottlerin to monitor the expression of B7-H4 and tumor metastasis.

Results

The B7-H4 expression level was significantly correlated with the p-PKCδ level (r = 0.378, P < 0.001) in tumor tissues. Coexpression of p-PKCδ and B7-H4 was significantly associated with moderate/poor differentiation (P = 0.024), lymph node metastasis (P = 0.001) and advanced Dukes’ stage (P = 0.002). Western blot analysis showed that Phorbol-12-Myristate-13-Acetate (TPA) increased B7-H4 expression in a concentration-dependent manner and that rottlerin abrogated the TPA-induced increase in B7-H4 expression. The protein levels of B7-H4 and p-STAT3 were significantly reduced by a PKCδ-specific siRNA. Moreover, the STAT3 inhibitor cryptotanshinone significantly decreased the B7-H4 protein level in CRC cells. Knockdown of B7-H4 or PKCδ suppressed cell migration and motility. Rottlerin also inhibited B7-H4 expression and tumor metastasis in vivo.

Conclusion

The B7-H4 expression level is significantly correlated with the p-PKCδ level and tumor metastasis in CRC samples. B7-H4 expression is upregulated by STAT3 activation via PKCδ and plays roles in PKCδ-induced cancer cell motility and metastasis, suggesting that the PKCδ/STAT3/B7-H4 axis may be a potential therapeutic target for CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02567-1.

Cancer Immunoediting: Elimination, Equilibrium, and Immune Escape in Solid Tumors

Emphasizing the dynamic processes between cancer and host immune system, the initially discovered concept of cancer immunosurveillance has been replaced by the current concept of cancer immunoediting consisting of three phases: elimination, equilibrium, and escape. Solid tumors composed of both cancer and host stromal cells are an example how the three phases of cancer immunoediting functionally evolve and how tumor shaped by the host immune system gets finally resistant phenotype. The elimination, equilibrium, and escape have been described in this chapter in details, including the role of immune surveillance, cancer dormancy, disruption of the antigen-presenting machinery, tumor-infiltrating immune cells, resistance to apoptosis, as well as the function of tumor stroma, microvesicles, exosomes, and inflammation.

Cancer immunotherapy by immune checkpoint blockade and its advanced application using bio-nanomaterials

Cancer is the second leading cause of death worldwide. Traditional approaches, such as surgery, chemotherapy, and radiotherapy have been the main cancer therapeutic modalities in recent years. Cancer immunotherapy is a novel therapeutic modality that potentiates the immune responses of patients against malignancy. Immune checkpoint proteins expressed on T cells or tumor cells serve as a target for inhibiting T cell overactivation, maintaining the balance between self-reactivity and autoimmunity. Tumors essentially hijack the immune checkpoint pathway in order to survive and spread. Immune checkpoint inhibitors (ICIs) are being developed as a result to reactivate the anti-tumor immune response. Recent advances in nanotechnology have contributed to the development of successful, safe, and efficient anticancer drug systems based on nanoparticles. Nanoparticle-based cancer immunotherapy overcomes numerous challenges and offers novel strategies for improving conventional immunotherapies. The fundamental and physiochemical properties of nanoparticles depend on various cancer therapeutic strategies, such as chemotherapeutics, nucleic acid-based treatments, photothermal therapy, and photodynamic agents. The review discusses the use of nanoparticles as carriers for delivering immune checkpoint inhibitors and their efficacy in cancer combination therapy.

Development of a novel anti-B7-H4 antibody enhances anti-tumor immune response of human T cells

BACKGROUND

B7-H4 is a member of the B7 superfamily that is expressed on the surface of tumors and exhibits limited expression on normal tissue. B7-H4 negatively regulates tumor immunity by interacting with the B7-H4 receptor, which is expressed by activated CD8 + T cells. Hence, we sought to generate an immunomodulatory antibody that targets B7-H4 and blocks the immunosuppressive activity of B7-H4.

METHODS

Anti-B7-H4 antibodies were generated using the hybridoma technique and screened by a binding assay based on B7-H4-expressing tumor cells. The B7-H4 antagonistic antibodies were further screened based on their checkpoint blockade activity using a SEB-stimulated peripheral blood mononuclear cell (PBMC) assay, which comprised B7-H4-expressing antigen presenting cells (APCs) and activated T cells. To assess the immunomodulatory activity of anti-B7-H4 antibodies, activated human CD8+ T cells were cultured in B7-H4 protein-coated plates, and the production of IL-2 and the proliferation rate of CD8+ T cells were measured. In addition, we evaluated the ADCC effect of anti-B7-H4 antibodies against tumor cell lines. The in vivo antitumor efficacy of the anti-B7-H4 antibody was also evaluated in human T cell-engrafted NOG mice.

RESULTS

A panel of anti-B7-H4 antibodies was generated. The top 23 antibodies were screened to identify antibodies that disabled B7-H4-mediated inhibition. Antibody 17 exhibited the greatest induction of the production of IL-2 and IFN-gamma in SEB-stimulated PBMCs. Antibody 17 was constructed as a chimeric antibody (CH17) with a human IgG1 constant domain. CH17 showed high affinity for human B7-H4 and fully cross-reacted with cynomolgus B7-H4. Additionally, CH17 mediated potent antibody-dependent cell cytotoxicity (ADCC) against different B7-H4-positive tumor cell lines. More importantly, CH17 relieved B7-H4-mediated T cell suppression by enhancing IL2 production and promoting T cell proliferation. In an MDA-MB-468-bearing mouse model in which human pan-T cells were engrafted, CH17 delayed tumor growth by engaging T cells and exerted a synergistic effect in combination with an anti-human PD-1 antibody.

CONCLUSIONS

We successfully generated an immunomodulatory antibody targeting B7-H4 that possesses both T cell immune checkpoint inhibitory activity and ADCC activity in B7-H4-positive tumors. B7-H4-targeting antibodies might represent a promising immunotherapy for B7-H4-expressing tumors.

CD47 Enhances Cell Viability and Migration Ability but Inhibits Apoptosis in Endometrial Carcinoma Cells via the PI3K/Akt/mTOR Signaling Pathway

Purposes: To measure expression levels of CD47 during endometrial carcinoma development, and to determine specific modulatory effects.

Methods: CD47 expression levels in endometrial carcinoma tissues and adjacent tissues were analyzed using qRT-PCR. CD47-overexpressed or downregulated cell models were established using CD47 plasmid or CD47 shRNA. The effects of CD47 on HEC-1A and Ishikawa cell growth were evaluated using CCK-8 assays. Migration ability of transfected HEC-1A and Ishikawa cells were examined using wound healing assays. Flow cytometry was used to measure the effects of CD47 on apoptosis and the cell cycle in HEC-1A and Ishikawa cells. Western blot was used to analyze the correlation between CD47 expression level and PI3K/Akt/mTOR signaling pathway.

Results: Highly expressed CD47 was observed in endometrial carcinoma tissues, with higher levels in more advanced tissues than in early tissues. Upregulation of CD47 enhanced cell viability and migration ability in HEC-1A and Ishikawa cells, while silencing CD47 caused the opposite results. CD47 overexpression suppressed apoptosis and inhibited cell cycle arrest in HEC-1A and Ishikawa cells. CD47 upregulation contributes to the activation of PI3K/Akt/mTOR signaling pathway in endometrial carcinoma cells.

Conclusion: CD47 exerts oncogenic functions in endometrial carcinoma by activating PI3K/Akt/mTOR signaling, suggesting it may be a novel immunotherapeutic target for therapeutic interventions.

B7-H4 is a potential prognostic biomarker of prostate cancer

B7-H4 is a member of B7 family which regulates immune responses by delivering costimulatory signals. However, it negatively regulates T cell-mediated immunity and may play an important role in tumor immune evasion. Although several studies have been reported that expression of B7-H4 is elevated in the several types of human cancer with a poor clinical outcome, its clinical significance in the prostate cancer (PCa) has not been well studied. In this study, we investigated the clinical significance of B7-H4 in human PCa and determined if B7-H4 expression is associated with the cancer cell stemness in PCa. Our studies show that expression of B7-H4 is correlated with the pathologic tumor (pT) stage and the clinical stage of PCa. The Kaplan-Meier survival analysis revealed that PCa patients with high expression of B7-H4 exhibits a shorter overall survival (OS) rate. Univariate and multivariate Cox regression analysis indicated that B7-H4 is an independent poor prognostic factor of PCa. In addition, the expression of B7-H4 is correlated with the cancer cell stemness associated genes expression in PCa. Further, our studies show that B7-H4 regulates cancer cell stemness associated genes expression and effects on the cell cycle and PI3K/Akt signaling related genes expression in PCa. These results indicate that B7-H4 expression is associated with cancer cell stemness, and B7-H4 is a potential prognostic biomarker and a therapeutic target of PCa.

Correlation between B7-H4 and Survival of Non-Small-Cell Lung Cancer Patients Treated with Nivolumab

Reliable predictors of benefit from immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) are still limited. We aimed to evaluate the association between the expression of selected molecules involved in immune response and clinical outcomes in NSCLC patients receiving nivolumab. In our study, the outcomes of 46 NSCLC patients treated with nivolumab in second or subsequent lines (Nivolumab Cohort) were compared with the expression of PD-L1, PD-L2, PD-1, B7-H3, and B7-H4 assessed by immunohistochemistry (IHC). Samples from 17 patients (37.0%) in the Nivolumab Cohort were positive for B7-H4 expression. At univariate analyses, only B7-H4 expression was associated with significantly decreased progression-free survival (PFS; 1.7 vs. 2.0 months; p = 0.026) and with a disadvantage in terms of overall survival (OS) close to statistical significance (4.4 vs. 9.8 months; p = 0.064). At multivariate analyses, B7-H4 expression was significantly associated with decreased PFS (hazard ratio (HR) = 2.28; p = 0.021) and OS (HR = 2.38; p = 0.022). Subsequently, B7-H4 expression was compared with clinical outcomes of 27 NSCLC patients receiving platinum-based chemotherapy (Chemotherapy Cohort), but no significant association was observed. Our results suggest a negative predictive role of B7-H4 in a population of NSCLC treated with immune checkpoint inhibitors, which deserves further research.

Harnessing immune checkpoints for cancer therapy

Immunomodulatory antibodies that directly trigger and reawaken suppressed T-cell effector function are termed 'checkpoint inhibitors'. CTLA-4 and PD-1/PD-L1 molecules are the most studied inhibitory immune check points against cancer and because of this therapeutic property have entered the clinic for treating a variety of tumor types. The results so far demonstrate a positive impact on cancer remission. Preclinical studies have demonstrated that targeting a number of other T-cell surface molecules including both positive and negative immune regulators, also possesses strong antitumor activity. Some of these molecules have already entered clinical trials. In this report, we briefly highlight the status of these immune checkpoint inhibitors and discuss their side effects and future directions for their use.

B7-H4 is highly expressed in aggressive Epstein-Barr virus positive diffuse large B-cell lymphoma and inhibits apoptosis through upregulating Erk1/2 and Akt signalling pathways

Background

B7-H4 is among the B7 family members which may serve as a new targetable immune checkpoint molecule. It was reported that high level of serum B7-H4 level may be correlated with lymphoma. Nevertheless, the role of B7-H4 in Epstein-Barr Virus-Positive diffuse large B cell lymphoma (EBV⁺DLBCL) has not been addressed although it has been suggested that B7-H4 could promote tumor growth and metastatic progression in certain cancers.

Methods

Between January 2005 and November 2017 at the department of Hematology, Shanghai Jiao Tong University School of Medicine affiliated Shanghai General Hospital 260 DLBCL samples were analyzed for EBV-encoded small RNA (EBV-EBER) by in situ hybridization. The expression level of B7-H4 in DLBCL tumor tissue was evaluated by immunohistochemistry. Furthermore, the role of B7-H4 in DLBCL was further investigated in DLBCL cell line.

Results

EBV⁺DLBCL patients suffered from markedly lower overall survival (OS) and progression-free survival (PFS) rates in our study. We showed that B7-H4 was significantly overexpressed in 16 EBV⁺-subgroup cases out of 260 DLBCL patients. We further found that EBV infection in lymphoblast cells led to enhanced expression of B7-H4 followed by increased cell viability and reduced apoptosis. In contrast, inhibition of B7-H4 simultaneously impaired cell viability and induced apoptosis. Mechanistically, inhibiting B7-H4 resulted in decreased phosphorylation Erk 1/2 and Akt.

Conclusion

Our study reveals a critical role of B7-H4 in EBV⁺DLBCL development by regulating cell survival and apoptosis through the Erk and Akt signalling pathways. Targetting B7-H4 may be promising in the therapy of EBV⁺DLBCL.

The CD28-B7 Family of Co-signaling Molecules

Immune responses are controlled by the optimal balance between protective immunity and immune tolerance. T-cell receptor (TCR) signals are modulated by co-signaling molecules, which are divided into co-stimulatory and co-inhibitory molecules. By expression at the appropriate time and location, co-signaling molecules positively and negatively control T-cell differentiation and function. For example, ligation of the CD28 on T cells provides a critical secondary signal along with TCR ligation for naive T-cell activation. In contrast, co-inhibitory signaling by the CD28-B7 family is important to regulate immune homeostasis and host defense, as these signals limit the strength and duration of immune responses to prevent autoimmunity. At the same time, microorganisms or tumor cells can use these pathways to establish an immunosuppressive environment to inhibit the immune responses against themselves. Understanding these co-inhibitory pathways will support the development of new immunotherapy for the treatment of tumors and autoimmune and infectious diseases. Here, we introduce diverse molecules belonging to the members of the CD28-B7 family.

Clinical Value of Combined Determination of Serum B7-H4 with Carcinoembryonic Antigen, Osteopontin, or Tissue Polypeptide-Specific Antigen for the Diagnosis of Colorectal Cancer

Aim

B7-H4 is member of the B7 family that negatively regulates the immune response, which are associated with tumor development and prognosis. The present study is aimed at examining serum B7-H4 expression and exploring its contribution to diagnosis in patients with colorectal cancer.

Methods

We determined serum expressions of B7-H4, carcinoembryonic antigen (CEA), osteopontin (OPN), and tissue polypeptide-specific antigen (TPS) in 59 patients with colorectal cancer and 29 healthy volunteers and analyzed the diagnostic value of B7-H4 combined with CEA, OPN, or TPS detection for colorectal cancer. B7-H4, OPN, and TPS serum expressions were measured by enzyme-linked immunosorbent assay, and CEA was measured by electrochemical luminescence detection.

Results

Serum B7-H4 levels were significantly higher in colorectal cancer patients compared with paired normal controls (P = 0.001). B7-H4 serum level was positively correlated with infiltration depth, tumor masses, and lymph node metastasis (P = 0.004, P = 0.016, and P = 0.0052, respectively). We also detected serum expression of B7-H4 before and after radical resection and showed that B7-H4 levels decreased significantly during the first week postoperation (P = 0.0064). We used receiver operating characteristic (ROC) curve analysis to indicate the potential diagnostic values of these markers. The areas under the ROC curves (AUC) for B7-H4, OPN, TPS, and CEA were 0.867, 0.805, 0.812, and 0.833, respectively. The optimal sensitivity and specificity of B7-H4 for discriminating between colon cancer patients and healthy controls were 88.2% and 86.7%, respectively, using a cut-off of value of 78.89 ng/mL. However, combined ROC analysis using B7-H4 and CEA revealed an AUC of 0.929, with a sensitivity of 98.9% and a specificity of 80.4% for discriminating colon cancer patients from healthy controls.

Conclusions

B7-H4 was highly expressed in the serum in colorectal cancer patients. Detection of B7-H4 plus CEA showed significantly increased sensitivity and specificity for discriminating between colorectal cancer patients and healthy controls compared to individual detection of these markers. Combined detection of serum B7-H4 and CEA may thus have the potential to become a new laboratory method for the early clinical diagnosis and prognostic evaluation of colorectal cancer.

Construction, expression and functional analysis of anti-B7-H4- scFv-CH3 recombinant antibody

The B7-H4 molecule, a unique negative regulator of T lymphocytes which is overexpressed on the surface of various tumor cells, is a particularly important target candidate for tumor therapy because it can be blocked with anti-B7-H4 antibodies to inhibit the B7-H4 signaling pathway. Our previous work established an anti-B7-H4 single-chain variable fragment (scFv) library, so we have now amplified the genes encoding anti-B7-H4-scFv and human IgG1 CH3 and ligated them by overlap extension PCR to obtain a recombinant gene. After sequencing, the gene was cloned into the expression vector pET43.1a and expression was induced in E. coli BL21 (DE3) by isopropyl-β-D-1-thiogalactopyranoside (IPTG). The protein was purified on a nickel-nitrilotriacetic acid (Ni-NTA) resin column and its antigen specificity and affinity were examined by ELISA and western blotting. We also established a Lewis lung cancer model in C57BL/6 mice to further identify the biological function of the scFv protein in vivo. The results showed that tumor volume, body weight and necrotic tissues in the control group were significantly greater than in the experimental group, indicating that selected scFvs had good biological activity and could inhibit tumor growth in tumor-bearing mice. Our work thus offers a new approach for the development of cancer-targeted therapy.

The prognostic value of B7-H4 in pancreatic cancer: Systematic review and meta-analysis

BACKGROUND

There were many reports suggesting that different kinds of tumors can express B7-H4; however, the prognostic value in cancer was still unclearly. Therefore, we conducted a meta-analysis to investigate the relationship between overexpression of B7-H4 with the prognostic value in pancreatic cancer patients.

MATERIALS AND METHODS

The Pubmed, Embase, Cochrane Library, Ovid, Web of Science, and Chinese research database (including CBM, CNKI, and WAN FANG) were searched for related literature published until October 12, 2017. The pooled odds ratios (ORs) and/or pooled hazard ratios (HRs) for clinical pathological factors and overall survival (OS) were calculated and analyzed using Stata software. To assess whether an individual study had an impact on the result, sensitivity analysis was performed for all included individual studies using the fixed-effects model. Publication bias was evaluated using Egger's and Begg's tests.

RESULTS

Data from 6 observational studies including 442 patients were summarized in this meta-analysis, and each study was eligible for inclusion based on included and exclude criteria. The pooled results indicated that the B7-H4 overexpression could predict the presentation of lymph node metastasis (OR = 3.94, 95% CI: 1.22-12.66, P = .022), advanced TNM stage (T = the extent of the primary tumor, N = regional lymph nodes, M = distant metastases) (III+IV vs I+II; OR = 7.63, 95% CI: 2.46-23.66, P < .001), and the poor OS (HR = 3.00, 95%CI = 2.20-4.10, P < .001) in PC patients.

CONCLUSIONS

This study reveals that high expression of B7-H4 is an unfavorable prognostic factor for patients with pancreatic cancer. These results may guide the clinical management of this patient population.

Prognostic role of high B7-H4 expression in patients with solid tumors: a meta-analysis

BACKGROUND

Recently, many studies have shown that B7-H4 exhibits altered expression in various cancers. We performed a meta-analysis to evaluate the prognostic role of B7-H4 expression in solid tumors.

RESULTS

Data from 18 observational studies and 2467 patients were summarized. An elevated baseline B7-H4 was significantly associated with worse OS (pooled HR = 1.79; 95% CI = 1.56-2.06). Differences across subgroups of tumor type, patients' ethnicity, analysis type, HR obtain method and cut-off value were not significant (PD = 0.313, PD = 0.716, PD = 0.896, PD = 0.290 and PD = 0.153, respectively). Furthermore, patients with high B7-H4 had a significantly shorter DFS (pooled HR = 2.12; 95%CI = 1.45-3.09).

MATERIALS AND METHODS

We searched PubMed, Embase and the Cochrane Library (last update by November 26, 2015) to identify studies assessing the effect of B7-H4 on survival of cancer patients. Pooled hazard ratios (HRs) for overall survival (OS) and disease-free survival (DFS) were estimated using fixed-effects models and random-effects models respectively.

CONCLUSIONS

This meta-analysis clarified that high B7-H4 expression in tissue was significantly associated with poor survival in patients with solid tumors. Future clinical studies are warranted to determine whether B7-H4 blockade has a favorable effect on disease recurrence and mortality.

Prognostic significance of B7-H4 expression in matched primary pancreatic cancer and liver metastases

Liver metastasis development in pancreatic cancer patients is common and confers a poor prognosis. Clinical relevance of biomarker analysis in metastatic tissue is necessary. B7-H4 has an inhibitory effect on T cell mediated response and may be involved in tumor development. Although B7-H4 expression has been detected in pancreatic cancer, its expression in liver metastases from pancreatic cancer is still unknown. In this study, overall 43 pancreatic cancer liver metastases (with matched primaries in 15/43 cases) and 57 pancreatic cancer cases without liver metastases or other distant metastases were analyzed for their expression of B7-H4 by immunohistochemistry. Survival curves and log-rank tests were used to test the association of B7-H4 expression with survival. B7-H4 was highly expressed in 28 (65.1%) of the 43 liver metastases and 9 (60.0%) of the 15 matched primary tumors. The expression of B7-H4 in liver metastases was significantly higher than in the matched primary tumors (p < 0.05). Patients with high B7-H4 expression in their primary pancreatic cancer had higher risk of developing liver metastases (p < 0.05). In univariate analysis, B7-H4 expression was significantly associated with the risk of death (p < 0.05). And the multivariate analysis identified that B7-H4 was an independent prognostic indicator (p < 0.05). Our results revealed B7-H4 to be associated with poor prognosis in patients with pancreatic cancer liver metastasis. B7-H4 may promote pancreatic cancer metastasis and was promising to be a potential prognostic indicator of pancreatic cancer.

B7-H4 as an independent prognostic indicator of cancer patients: a meta-analysis

The expression of B7-H4 was observed in a variety of tumors, however the prognostic value in cancer was still controversial. Therefore, we conducted this meta-analysis to explore the potential role of B7-H4 in cancer prognostic prediction. Twenty-seven studies including 3771 patients were brought into the analysis according to the inclusion and exclusion criteria. The pooled results demonstrated that elevated B7-H4 predicted a poor OS (HR = 1.93, 95% CI 1.71-2.18, P < 0.001) and DFS (HR = 1.84, 95% CI 1.46-2.33, P < 0.001). Subgroup analysis showed that races, tumor types, sample sources, analysis types, sources of HR and sample sizes exhibited non-significant distinctions with OS (P_S = 0.878, P_S = 0.143, P_S = 0.613, P_S = 0.639, P_S = 0.48 and P_S = 0.528, respectively). PubMed, Embase and the Cochrane Library were searched up to April 7, 2017, to recognize the available studies for assessing the association between B7-H4 and cancer patients’ outcome. We extracted the hazard ratio (HR), relative ratio (RR), odds ratio (OR) with their 95% confidence interval (CI) for overall survival (OS) or disease-free survival (DFS) as the effect size (ES) for the analysis. This meta-analysis demonstrates high expression of B7-H4 is a negative correlation with the outcome of cancer patients.

Differential Expression and Significance of PD-L1, IDO-1, and B7-H4 in Human Lung Cancer

PURPOSE

To determine the expression level, associations, and biological role of PD-L1, IDO-1, and B7-H4 in non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Using multiplexed quantitative immunofluorescence (QIF), we measured the levels of PD-L1, IDO-1, B7-H4, and different tumor-infiltrating lymphoycte (TIL) subsets in 552 stages I-IV lung carcinomas from two independent populations. Associations between the marker levels, TILs, and major clinicopathologic variables were determined. Validation of findings was performed using mRNA expression data from The Cancer Genome Atlas (TCGA) and in vitro stimulation of lung adenocarcinoma A549 cells with IFNγ and IL10.

RESULTS

PD-L1 was detected in 16.9% and 21.8% of cases in each population. IDO-1 was expressed in 42.6% and 49.8%; and B7-H4 in 12.8% and 22.6% of cases, respectively. Elevated PD-L1 and IDO-1 were consistently associated with prominent B- and T-cell infiltrates, but B7-H4 was not. Coexpression of the three protein markers was infrequent, and comparable results were seen in the lung cancer TCGA dataset. Levels of PD-L1 and IDO-1 (but not B7-H4) were increased by IFNγ stimulation in A549 cells. Treatment with IL10 upregulated B7-H4 but did not affect PD-L1 and IDO-1 levels.

CONCLUSIONS

PD-L1, IDO-1, and B7-H4 are differentially expressed in human lung carcinomas and show limited co-expression. While PD-L1 and IDO-1 are associated with increased TILs and IFNγ stimulation, B7-H4 is not. The preferential expression of discrete immune evasion pathways in lung cancer could participate in therapeutic resistance and support design of optimal clinical trials. Clin Cancer Res; 23(2); 370-8. ©2016 AACR.

B7-H4 facilitates proliferation of esophageal squamous cell carcinoma cells through promoting interleukin-6/signal transducer and activator of transcription 3 pathway activation

B7‐H4, one of the costimulatory molecules of the B7 family, has been found to be widely expressed in many kinds of tumor tissues and to play an important part in tumor progression and poor prognosis. However, the role of B7‐H4 in esophageal squamous cell carcinoma (ESCC) cells has not been elucidated. In this study, we found that, compared with normal esophageal tissue, B7‐H4 was highly expressed in three ESCC cell lines, Eca109, TE1, and TE13. B7‐H4 silenced cells suppressed cellular proliferation and colony formation. Additionally, compared with control cells, B7‐H4 silenced cells showed higher apoptosis rates, Bcl‐2 and Survivin upregulation, and BAX downregulation. Further study revealed that B7‐H4 silenced cells also showed reduction in interleukin‐6 (IL‐6) secretion, signal transducer and activator of transcription 3 (STAT3) activation, and p‐STAT3 translocation from cytoplasm to nucleus. Moreover, B7‐H4 depletion inhibited the IL‐6 secretion of control cells but not JAK2/STAT3 inhibitor FLLL32‐treated cells. Interleukin‐6 receptor antagonist tocilizumab did not block the p‐JAK2 or p‐STAT3 downregulation induced by B7‐H4 silence. It was suggested that B7‐H4 silence suppressed IL‐6 secretion through JAK2/STAT3 inactivation. Furthermore, cell proliferation and colony formation were downregulated by tocilizumab in control cells but not in B7‐H4 silenced cells, indicating that IL‐6 upregulation induced by B7‐H4 was necessary for cell growth. On the other hand, B7‐H4 expression was downregulated by tocilizumab. In all, our study provided the first evidence that B7‐H4 facilitated ESCC cell proliferation through promoting IL‐6/STAT3 positive loopback pathway activation.

Clinical relevance of expression of B7-H1 and B7-H4 in ovarian cancer

The aim of the present study was to investigate the expression of B7-H1 and B7-H4 in ovarian neoplasm tissues and to examine their clinical relevance. A total of 112 ovarian biopsies were collected from patients with epithelial ovarian cancer (EOC) and 10 were taken from ovarian benign neoplasms. The samples were processed in paraffin tissue chips, and subjected to immunohistochemical staining and analysis. Associations of B7-H1 and B7-H4 expression with patients' clinical parameters, such as histological typing, cell grading, International Federation of Gynecology and Obstetrics staging, tumor size, and metastatic status, were examined by statistical analysis. Survival curves were constructed using the Kaplan-Meier method and the log-rank test. Independent prognostic factors were evaluated using the Cox regression model. The results showed an extremely low or negative expression of B7-H1 and B7-H4 in the 10 benign ovarian neoplasm tissues (control): By contrast, a positive expression of B7-H1 and B7-H4 was observed in 55.4% (62/112) and 37.5% (42/112) of the EOC tissues, respectively. The differences between the two groups were significant. In addition, the co-expression of B7-H1 and B7-H4 was found in 31.3% (35/112) of the EOC cases. Furthermore, the progression-free survival and overall survival were significantly lower in EOC patients with a high expression of B7-H1 and B7-H4 (χ²=45.60 and 37.99, respectively). These results demonstrated that the expression of B7-H1 and B7-H4 in EOC tissues was significantly associated with poor prognosis and high relapse rate of EOC. The findings suggest that B7-H1 and B7-H4 is a negative prognostic marker for EOC and a potential immunotherapeutic target for patients with EOC.

Loss of Peripheral Protection in Pancreatic Islets by Proteolysis-Driven Impairment of VTCN1 (B7-H4) Presentation Is Associated with the Development of Autoimmune Diabetes

Ag-specific activation of T cells is an essential process in the control of effector immune responses. Defects in T cell activation, particularly in the costimulation step, have been associated with many autoimmune conditions, including type 1 diabetes (T1D). Recently, we demonstrated that the phenotype of impaired negative costimulation, due to reduced levels of V-set domain-containing T cell activation inhibitor 1 (VTCN1) protein on APCs, is shared between diabetes-susceptible NOD mice and human T1D patients. In this study, we show that a similar process takes place in the target organ, as both α and β cells within pancreatic islets gradually lose their VTCN1 protein during autoimmune diabetes development despite upregulation of the VTCN1 gene. Diminishment of functional islet cells' VTCN1 is caused by the active proteolysis by metalloproteinase N-arginine dibasic convertase 1 (NRD1) and leads to the significant induction of proliferation and cytokine production by diabetogenic T cells. Inhibition of NRD1 activity, alternatively, stabilizes VTCN1 and dulls the anti-islet T cell responses. Therefore, we suggest a general endogenous mechanism of defective VTCN1 negative costimulation, which affects both lymphoid and peripheral target tissues during T1D progression and results in aggressive anti-islet T cell responses. This mechanism is tied to upregulation of NRD1 expression and likely acts in two synergistic proteolytic modes: cell-intrinsic intracellular and cell-extrinsic systemic. Our results highlight an importance of VTCN1 stabilization on cell surfaces for the restoration of altered balance of immune control during T1D.

B7-H4 downregulation induces mitochondrial dysfunction and enhances doxorubicin sensitivity via the cAMP/CREB/PGC1-α signaling pathway in HeLa cells

B7-H4 is a B7 family coregulatory protein that inhibits T cell-mediated immunity. B7-H4 is overexpressed in various cancers; however, the functional role of B7-H4 in cancer metabolism is poorly understood. Because mitochondria play pivotal roles in development, proliferation, and death of cancer cells, we investigated molecular and functional alterations of mitochondria in B7-H4-depleted HeLa cells. In a human study, overexpression of B7-H4 was confirmed in the cervices of adenocarcinoma patients (n = 3) compared to noncancer patients (n = 3). In the cell line model, B7-H4 depletion was performed by transfection with small interfering RNA (siRNA). B7-H4 depletion suppressed oxygen consumption rate, ATP production, and mitochondrial membrane potential and mass and increased reactive oxygen species production. In particular, electron transport complex III activity was significantly impaired in siB7-H4-treated cells. Coincidently, depletion of B7-H4 suppressed major mitochondrial regulators (peroxisome proliferator-activated receptor gamma coactivator 1-alpha [PGC1-α] and mitochondrial transcription factor A), a component of oxidative phosphorylation (ubiquinol-cytochrome c reductase core protein 1), and an antiapoptosis protein (Bcl-XL). Mitochondrial dysfunction in siRNA-treated cells significantly augmented oxidative stress, which strongly activated the JNK/P38/caspase axis in the presence of doxorubicin, resulting in increased apoptotic cell death. Investigating the mechanism of B7-H4-mediated mitochondrial modulation, we found that B7-H4 depletion significantly downregulated the cAMP/cAMP response element-binding protein/PGC1-α signaling pathway. Based on these findings, we conclude that B7-H4 has a role in the regulation of mitochondrial function, which is closely related to cancer cell physiology and drug sensitivity.

Expression of immune checkpoint molecules in endometrial carcinoma

The main obstacle in the development of an effective tumor vaccine is the inherent ability of tumors to evade immune responses. Tumors often use common immune mechanisms and regulators to evade the immune system. The present study aimed to analyze the expression levels of indoleamine 2,3-dioxygenase (IDO), programmed death-ligand (PD-L) 1, PD-L2, B7-H4, galectin-1 and galectin-3 in tissue samples from patients with endometrial carcinoma, in order to detect the immunosuppressive environment of endometrial carcinomas. The levels of IDO, PD-L1, PD-L2 and B7-H4 were analyzed by immunohistochemical methods, and the levels of galectin-1 and galectin-3 in tumor lysates were determined using ELISA. PD-L2 was expressed at low levels in the majority of tumor samples. IDO expression was detected in 38, 63 and 43% of primary endometrial carcinoma, recurrent endometrial carcinoma, and metastatic endometrial carcinoma specimens, respectively. Positive expression rates for PD-L1 were 83% in primary endometrial carcinoma, 68% in recurrent endometrial carcinoma, and 100% in metastatic endometrial carcinoma, whereas B7-H4 expression was detected in 100% of both primary endometrial carcinoma and recurrent endometrial carcinoma samples, and in 96% of metastatic endometrial carcinoma specimens. The expression levels of galectin-1 and galectin-3 were not significantly different between the normal and tumor specimens. The results of the present study suggest that the interaction between PD-1/PD-L1 and B7-H4 may be a potential target for immune intervention in the treatment of endometrial carcinoma. Furthermore, the results may provide the basis for immunosuppressant therapy in the treatment of patients with uterine cancer.

Inhibitory receptors as targets for cancer immunotherapy

Inhibitory receptors expressed on T cells control immune responses while limiting autoimmunity. However, tumors can hijack these "checkpoints" for protection from immune attack. Tumor-specific T cells that exhibit an exhausted, unresponsive phenotype express high levels of inhibitory receptors including CTLA4, PD1, and LAG3, among others. Intratumoral regulatory T cells promote immunosuppression and also express multiple inhibitory receptors. Overcoming this inhibitory receptor-mediated immune tolerance has thus been a major focus of recent cancer immunotherapeutic developments. Here, we review how boosting the host's immune system by blocking inhibitory receptor signaling with antagonistic mAbs restores the capacity of T cells to drive durable antitumor immune responses. Clinical trials targeting the CTLA4 and PD1 pathways have shown durable effects in multiple tumor types. Many combinatorial therapies are currently being investigated with encouraging results that highlight enhanced antitumor immunogenicity and improved patient survival. Finally, we will discuss the ongoing identification and dissection of novel T-cell inhibitory receptor pathways, which could lead to the development of new combinatorial therapeutic approaches.

Cancer and the Immune System: Basic Concepts and Targets for Intervention

A number of consensuses regarding cancer immunology have recently emerged from both preclinical immunotherapy models and analysis of cancer patients. First and foremost, the natural state of endogenous tumor reactive T cells is characterized by general hyporesponsiveness or anergy. This is likely due to a number of mechanisms that tumors use to induce tolerance as they develop. While many of the newer generation vaccines can effectively transfer antigen to and activate dendritic cells, T-cell tolerance remains a major barrier that is difficult to overcome by vaccination alone. Preclinical models demonstrate that for poorly immunogenic tumors, once tolerance has been established, therapeutic vaccines alone are ineffective at curing animals with a significant established tumor burden. However, combination strategies of vaccination together with inhibitors of immunologic checkpoints and agonists for co-stimulatory pathways are proving capable of overcoming tolerance and generating significant anti-tumor responses even in cases of established metastatic cancer.

B7-H4 expression is associated with tumor progression and prognosis in patients with osteosarcoma

Increasing evidences have demonstrated that B7-H4 is associated with tumor development and prognosis. However, the clinical significance of B7-H4 expression in human osteosarcoma (OS) remains unclear. The aim of present study was to examine the B7-H4 expression and to explore its contribution in OS. B7-H4 expression in OS tissues was examined by immunohistochemistry. Soluble B7-H4 (sB7-H4) levels in blood were examined by ELISA. The association of B7-H4 expression with clinicopathological factors or prognosis was statistically analyzed. Our findings demonstrated that B7-H4 expression in OS tissues was significantly higher than those in paired normal bone tissues (P < 0.001). sB7-H4 level in OS serum samples was significantly higher than that in healthy controls (P = 0.005). High B7-H4 expression in tissues and sB7-H4 level were both correlated with advanced tumor stage (P < 0.001, P = 0.017, resp.) and distant metastasis (P = 0.034, P = 0.021, resp.). Additionally, high B7-H4 expression or serum sB7-H4 levels were significantly related to poor overall survival (P = 0.028, P = 0.005, resp.). B7-H4 in tissues and serum samples were an independent factor for affecting the survival time of OS patients (P = 0.004, P = 0.041, resp.). Collectively, our data suggest that the evaluation of B7-H4 expression in tissues and blood is a useful tool for predicting the progression of osteosarcoma and prognosis.

The CD28-B7 Family in Anti-Tumor Immunity: Emerging Concepts in Cancer Immunotherapy

The interactions between B7 molecules and CD28-family receptors are crucial in the regulation of adaptive cellular immunity. In cancer, the aberrant expression of co-inhibitory B7 molecules has been attributed to reduced anti-tumor immunity and cancer immune evasion, prompting the development of cancer therapeutics that can restore T cell function. Murine tumor models have provided significant support for the targeting of multiple immune checkpoints involving CTLA-4, PD-1, ICOS, B7-H3 and B7-H4 during tumor growth, and clinical studies investigating the therapeutic effects of CTLA-4 and PD-1 blockade have shown exceptionally promising results in patients with advanced melanoma and other cancers. The expression pattern of co-inhibitory B7 ligands in the tumor microenvironment has also been largely correlated with poor patient prognosis, and recent evidence suggests that the presence of several B7 molecules may predict the responsiveness of immunotherapies that rely on pre-existing tumor-associated immune responses. While monotherapies blocking T cell co-inhibition have beneficial effects in reducing tumor burden, combinatorial immunotherapy targeting multiple immune checkpoints involved in various stages of the anti-tumor response has led to the most substantial impact on tumor reduction. In this review, we will examine the contributions of B7- and CD28-family members in the context of cancer development, and discuss the implications of current human findings in cancer immunotherapy.

Mapping the immunosuppressive environment in uterine tumors: implications for immunotherapy

The major hurdle for cancer vaccines to be effective is posed by tumor immune evasion. Several common immune mechanisms and mediators are exploited by tumors to avoid immune destruction. In an attempt to shed more light on the immunosuppressive environment in uterine tumors, we analyzed the presence of PD-L1, PD-L2, B7-H4, indoleamine 2,3-dioxygenase (IDO), galectin-1, galectin-3, arginase-1 activity and myeloid-derived suppressor cell (MDSC) infiltration. IDO, PD-L1, PD-L2 and B7-H4 were analyzed by immunohistochemistry. PD-L2 was mostly expressed at low levels in these tumors. We found high IDO expression in 21 % of endometrial carcinoma samples and in 14 % of uterine sarcoma samples. For PD-L1 and B7-H4, we found high expression in 92 and 90 % of endometrial cancers, respectively, and in 100 and 92 % of the sarcomas. Galectin-1 and 3 were analyzed in tissue lysates by ELISA, but we did not find an increase in both molecules in tumor lysates compared with benign tissues. We detected expression of galectin-3 by fibroblasts, immune cells and tumor cells in single-cell tumor suspensions. In addition, we noted a highly significant increase in arginase-1 activity in endometrial carcinomas compared with normal endometria, which was not the case for uterine sarcomas. Finally, we could demonstrate MDSC infiltration in fresh tumor suspensions from uterine tumors. These results indicate that the PD-1/PD-L1 interaction and B7-H4 could be possible targets for immune intervention in uterine cancer patients as well as mediation of MDSC function. These observations are another step toward the implementation of inhibitors of immunosuppression in the treatment of uterine cancer patients.

Microenvironment, oncoantigens, and antitumor vaccination: lessons learned from BALB-neuT mice

The tyrosine kinase human epidermal growth factor receptor 2 (HER2) gene is amplified in approximately 20% of human breast cancers and is associated with an aggressive clinical course and the early development of metastasis. Its crucial role in tumor growth and progression makes HER2 a prototypic oncoantigen, the targeting of which may be critical for the development of effective anticancer therapies. The setup of anti-HER2 targeting strategies has revolutionized the clinical outcome of HER2⁺ breast cancer. However, their initial success has been overshadowed by the onset of pharmacological resistance that renders them ineffective. Since the tumor microenvironment (TME) plays a crucial role in drug resistance, the design of more effective anticancer therapies should depend on the targeting of both cancer cells and their TME as a whole. In this review, starting from the successful know-how obtained with a HER2⁺ mouse model of mammary carcinogenesis, the BALB-neuT mice, we discuss the role of TME in mammary tumor development. Indeed, a deeper knowledge of antigens critical for cancer outbreak and progression and of the mechanisms that regulate the interplay between cancer and stromal cell populations could advise promising ways for the development of the best anticancer strategy.

B7-H4 as a potential target for immunotherapy for gynecologic cancers: a closer look

B7-H4 is a transmembrane protein that binds an unknown receptor on activated T cells resulting in inhibition of T-cell effector function via cell cycle arrest, decreased proliferation, and reduced IL-2 production. B7-H4 is up-regulated on the surface of cancer cells and immunosuppressive tumor-associated macrophages (TAMs) in a variety of human cancers. Notably, B7-H4 expression levels inversely correlate with patient survival in ovarian cancer, making B7-H4 an attractive candidate for therapeutic intervention. Here, we summarize the experimental data and methodologies that have revealed B7-H4's mRNA and protein expression and function in both mice and humans since its discovery in 2003, with a specific focus on B7-H4's role in ovarian cancer. We also underscore the discrepancies in published data due to high variability in methodology and use of different antibodies, most of which are not commercially available. Finally, since B7-H4 is expressed on tumor cells and TAMs in various cancer types, directing therapeutics against B7-H4 could have tremendous synergistic outcomes in favorably altering the tumor micro-environment and eliminating cancer cells. We highlight the therapeutic potential of targeting B7-H4, both by comparing other negative immune modulators such as PD-1 and CTLA-4 and by identifying novel methods to target B7-H4 directly or indirectly to overcome B7-H4-mediated T-cell inhibition.

Armed therapeutic viruses - a disruptive therapy on the horizon of cancer immunotherapy

For the past 150 years cancer immunotherapy has been largely a theoretical hope that recently has begun to show potential as a highly impactful treatment for various cancers. In particular, the identification and targeting of immune checkpoints have given rise to exciting data suggesting that this strategy has the potential to activate sustained antitumor immunity. It is likely that this approach, like other anti-cancer strategies before it, will benefit from co-administration with an additional therapeutic and that it is this combination therapy that may generate the greatest clinical outcome for the patient. In this regard, oncolytic viruses are a therapeutic moiety that is well suited to deliver and augment these immune-modulating therapies in a highly targeted and economically advantageous way over current treatment. In this review, we discuss the blockade of immune checkpoints, how oncolytic viruses complement and extend these therapies, and speculate on how this combination will uniquely impact the future of cancer immunotherapy.

B7-H abnormalities in melanoma and clinical relevance

Melanoma have been shown to escape immune surveillance by different mechanisms such as loss of HLA class I antigens, upregulation of nonclassical HLA-G antigen and Fas, increased secretion of immune suppressive cytokines and metabolites as well as altered expression of co-stimulatory and coinhibitory signals. Recently, an important role of B7-H1 and B7-H4 in the immune escape of melanoma has been described. High mRNA and/or protein expression levels of these coinhibitory molecules were detected in both melanoma cell lines and melanoma lesions when compared to melanocytes. However, their clinical relevance is currently controversially discussed regarding a correlation of B7-H family members with tumor grading and staging as well as survival of patients in melanoma.

Genetic variation in VTCN1 (B7-H4) is associated with course of disease in juvenile idiopathic arthritis

OBJECTIVE

The course of disease in juvenile idiopathic arthritis (JIA) is unpredictable with episodes of activity and remission. In order to identify predictive factors, 93 SNPs, JIA subtype, age at onset and ANA status were studied in relation to disease course.

METHODS

Genetic and clinical parameters were analysed in a cohort of 272 Caucasian patients with persistent oligoarthritis (n=129), extended oligoarthritis (n=57) and rheumatoid factor negative polyarthritis (n=86). Categories of disease course (remitting (n=65), intermediate (n=96) and unremitting (n=111)) were designed based on the cumulative time spent in active disease in the first 2 years.

RESULTS

Univariate analysis revealed association of the course of disease with JIA subtype (p=5.7*10(-5)) and three SNPs; VTCN1 rs10 923 223 (p=4.4*10(-5)), VTCN1 rs12 046 117 (p=0.017) and CDK6 rs42 041 (p=0.038). In a subsequent multivariate ordinal logistic regression analysis, VTCN1 rs10 923 223 (OR 0.41, 95%-CI 0.26 to 0.63) and JIA subtype (OR 3.8, 95%-CI 2.0 to 7.2; OR 2.5, 95%-CI 1.4 to 4.2, for extended oligoarthritis and RF-negative polyarthritis vs persistent oligoarthritis, respectively) were the strongest independent factors for course of disease.

CONCLUSIONS

This study provides evidence that VTCN1, encoding B7-H4, is associated with course of disease in selected subtypes of JIA. VTCN1 might be useful in predicting the course of disease.

B7-H4 overexpression correlates with a poor prognosis for cervical cancer patients

Cervical cancer is a major global public health care concern and the second most commonly diagnosed malignancy among females worldwide. B7-H4 is an immunoregulatory protein that has been shown to be overexpressed in several types of cancer and is often associated with more advanced disease and poor prognosis. We investigated whether B7-H4 is a prognostic maker for cervical cancer by detecting its expression in cervical cancer specimens. Formalin-fixed, paraffin-embedded tissue blocks from cervical cancer were evaluated for B7-H4 expression by immunohistochemistry with free R software analysis. The intensity of B7-H4 immunoexpression was evaluated according to age, histological type, International Federation of Gynecology and Obstetrics (FIGO) stage, lymphovascular space invasion (LVSI) and lymph node status. We investigated the distribution and expression of B7-H4 in 102 cervical cancer specimens and determined the association between its expression and clinicopathological characteristics, including patient outcomes. Of the 102 specimens, 31 were found to be negative for B7-H4 immunoexpression, whereas 71 were B7-H4-positive. When classified by negative vs. positive expression, B7-H4 was not found to be associated with any of the clinicopathological parameters investigated. A positive B7-H4 expression significantly predicted poor overall survival (OS) when compared to negative expression (P<0.05). In the multivariate analysis, positive B7-H4 expression was identified as an independent prognostic factor for OS (P<0.05). Our data suggested that positive B7-H4 expression may be a useful biomarker in patients with cervical cancer likely to have an unfavorable clinical outcome.

Coinhibitory molecules in cancer biology and therapy

The adaptive immune response is controlled by checkpoints represented by coinhibitory molecules, which are crucial for maintaining self-tolerance and minimizing collateral tissue damage under physiological conditions. A growing body of preclinical evidence supports the hypothesis that unleashing this immunological break might be therapeutically beneficial in the fight against cancer, as it would elicit an effective antitumor immune response. Remarkably, recent clinical trials have demonstrated that this novel strategy can be highly effective in the treatment of patients with cancer, as shown by the paradigmatic case of ipilimumab (a monoclonal antibody blocking the coinhibitory molecule cytotoxic T lymphocyte associated antigen-4 [CTLA4]) that is opening a new era in the therapeutic approach to a chemoresistant tumor such as cutaneous melanoma. In this review we summarize the biology of coinhibitory molecules, overview the experimental and clinical attempts to interfere with these immune checkpoints to treat cancer and critically discuss the challenges posed by such a promising antitumor modality.

MODULATING CO-STIMULATION DURING ANTIGEN PRESENTATION TO ENHANCE CANCER IMMUNOTHERAPY

One of the key roles of the immune system is the identification of potentially dangerous pathogens or tumour cells, and raising a wide range of mechanisms to eliminate them from the organism. One of these mechanisms is activation and expansion of antigen-specific cytotoxic T cells, after recognition of antigenic peptides on the surface of antigen presenting cells such as dendritic cells (DCs). However, DCs also process and present autoantigens. Therefore, antigen presentation has to occur in the appropriate context to either trigger immune responses or establishing immunological tolerance. This is achieved by co-stimulation of T cells during antigen presentation. Co-stimulation consists on the simultaneous binding of ligand-receptor molecules at the immunological synapse which will determine the type and extent of T cell responses. In addition, the type of cytokines/chemokines present during antigen presentation will influence the polarisation of T cell responses, whether they lead to tolerance, antibody responses or cytotoxicity. In this review, we will focus on approaches manipulating co-stimulation during antigen presentation, and the role of cytokine stimulation on effective T cell responses. More specifically, we will address the experimental strategies to interfere with negative co-stimulation such as that mediated by PD-L1 (Programmed cell death 1 ligand 1)/PD-1 (Programmed death 1) to enhance anti-tumour immunity.

A review of B7-H3 and B7-H4 immune molecules and their role in ovarian cancer

A number of members of the B7 superfamily of ligands have been implicated in tumor immunogenicity and cancer development. Two of these recently characterized ligands, B7-H4 and B7-H3, have been linked to ovarian tumors. B7-H4 is consistently overexpressed in ovarian tumor specimens, and its tissue and serum levels have been found to be a potential biomarker for ovarian cancer, either alone or in combination with CA125. More recently, B7-H3 has been found to be overexpressed in a large series of ovarian cancer tumor specimens and similar to other types of carcinomas, B7-H3 overexpression has been correlated with poor survival. On the basis of the results obtained by knocking down B7-H3 protein using siRNA, researchers have suggested that blocking the action of B7-H3 could reduce tumor growth, metastatic potential, and improve survival. Because siRNA knock-down is not an ideal clinical therapeutic vehicle, additional studies using antibody-mediated suppression of the B7-H3 protein are necessary to fully evaluate the clinical potential of this molecule as a therapeutic target.

The expression, function, and clinical relevance of B7 family members in cancer

The modulation and suppression of anti-tumor immune responses is a characteristic feature of tumor cells to escape immune surveillance. Members of the B7 family are involved in this process, since the level of activation of the anti-tumor immune response depends on the balance between co-stimulatory and co-inhibitory signals. Some molecules are often overexpressed in tumors, which has been associated with the pathogenesis and progression of malignancies as well as their immunological and non-immunological functions. The B7 homologs play a key role in the maintenance of self-tolerance and the regulation of both innate and adaptive immunity in tumor-bearing hosts. Furthermore, the blockade of negative signals mediated by the interaction of co-inhibitory ligands and counter-receptors of the B7 family is currently being studied as a potential immunotherapeutic strategy for the treatment of cancer in humans.

The blockade of immune checkpoints in cancer immunotherapy

Among the most promising approaches to activating therapeutic antitumour immunity is the blockade of immune checkpoints. Immune checkpoints refer to a plethora of inhibitory pathways hardwired into the immune system that are crucial for maintaining self-tolerance and modulating the duration and amplitude of physiological immune responses in peripheral tissues in order to minimize collateral tissue damage. It is now clear that tumours co-opt certain immune-checkpoint pathways as a major mechanism of immune resistance, particularly against T cells that are specific for tumour antigens. Because many of the immune checkpoints are initiated by ligand-receptor interactions, they can be readily blocked by antibodies or modulated by recombinant forms of ligands or receptors. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) antibodies were the first of this class of immunotherapeutics to achieve US Food and Drug Administration (FDA) approval. Preliminary clinical findings with blockers of additional immune-checkpoint proteins, such as programmed cell death protein 1 (PD1), indicate broad and diverse opportunities to enhance antitumour immunity with the potential to produce durable clinical responses.

Immunotherapy earns its spot in the ranks of cancer therapy

Since it became clear that all cancer cells express tumor-specific and tumor-selective antigens generated by genetic alterations and epigenetic dysregulation, the immunology community has embraced the possibility of designing therapies to induce targeted antitumor immune responses. The potential therapeutic specificity and efficacy of such treatments are obvious to anyone who studies the exquisite specificity and cytocidal potency of immune responses. However, the value assigned to a therapeutic modality by the oncology community at large does not depend on scientific principle; all that matters is how patients respond. The bar for the ultimate acceptance of a therapy requires more than anecdotal clinical responses; rather, the major modalities of cancer therapeutics, including surgery, chemotherapy, radiation therapy, and, more recently, drugs targeting oncogenes, have earned their place only after producing dramatic frequent clinical responses or demonstrating statistically significant survival benefits in large randomized phase 3 clinical trials, leading to FDA approval. Although tumor-targeted antibodies have certainly cleared this bar, immunotherapies aimed at harnessing antitumor cellular responses have not-until now.

Targeting costimulatory molecules to improve antitumor immunity

The full activation of T cells necessitates the concomitant activation of two signals, the engagement of T-cell receptor by peptide/major histocompatibility complex II and an additional signal delivered by costimulatory molecules. The best characterized costimulatory molecules belong to B7/CD28 and TNF/TNFR families and play crucial roles in the modulation of immune response and improvement of antitumor immunity. Unfortunately, tumors often generate an immunosuppressive microenvironment, where T-cell response is attenuated by the lack of costimulatory molecules on the surface of cancer cells. Thus, targeting costimulatory pathways represent an attractive therapeutic strategy to enhance the antitumor immunity in several human cancers. Here, latest therapeutic approaches targeting costimulatory molecules will be described.