Cytoplasmic expression of B7-H3 and membranous EpCAM expression are associated with higher grade and survival outcomes in patients with clear cell renal cell carcinoma

B7-H3 in acute myeloid leukemia: From prognostic biomarker to immunotherapeutic target

ABSTRACT

B7-H3 (CD276), an immune checkpoint protein of the B7 family, exhibits significant upregulation in solid tumors and hematologic malignancies, exerting a crucial role in their pathophysiology. The distinct differential expression of B7-H3 between tumors and normal tissues and its multifaceted involvement in tumor pathogenesis position it as a promising therapeutic target for tumors. In the context of acute myeloid leukemia (AML), B7-H3 is prominently overexpressed and closely associated with unfavorable prognoses, yet it has remained understudied. Despite various ongoing clinical trials demonstrating the potential efficacy of immunotherapies targeting B7-H3, the precise underlying mechanisms responsible for B7-H3-mediated proliferation and immune evasion in AML remain enigmatic. In view of this, we comprehensively outline the current research progress concerning B7-H3 in AML, encompassing in-depth discussions on its structural attributes, receptor interactions, expression profiles, and biological significance in normal tissues and AML. Moreover, we delve into the protumor effects of B7-H3 in AML, examine the intricate mechanisms that underlie its function, and discuss the emerging application of B7-H3-targeted therapy in AML treatment. By juxtaposing B7-H3 with other molecules within the B7 family, this review emphasizes the distinctive advantages of B7-H3, not only as a valuable prognostic biomarker but also as a highly promising immunotherapeutic target in AML.

CD276 is a promising biomarker for the prognosis of clear cell renal cell carcinoma

This study aimed to investigate the role of cluster of differentiation 276 (CD276) in evaluating the prognosis of clear cell renal carcinoma (ccRCC) and to build a nomogram for predicting ccRCC progression post-surgery. Using data downloaded from The Cancer Genome Atlas (TCGA) database, we constructed a Kaplan-Meier (KM) curve depicting the relationship between CD276 expression levels and the progression-free interval (PFI) in 539 ccRCC cases. We further validated this by plotting a KM curve of the relationship between CD276 expression levels and PFI in 116 ccRCC patients from our hospital. Using clinical data collected from 116 patients, we identified independent risk factors affecting postoperative PFI in patients with ccRCC through univariate and multivariate COX analyses and created a nomogram for visual representation. Both TCGA and clinical data revealed a negative correlation between the expression levels of CD276 and PFI (p < 0.05). Univariate COX analysis revealed that the prognostic nutritional index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, systemic inflammatory index, World Health Organization grading, tumor diameter, CD276 expression levels, T stage, and N stage were related to PFI (p < 0.05). Furthermore, multivariate COX analysis indicated that tumor diameter and CD276 expression levels were independent risk factors for postoperative PFI in patients with ccRCC (p < 0.05). The calibration curve of the established nomogram exhibited a slope close to 1, with a Hosmer-Lemeshow goodness-of-fit test result of 2.335 and a p-value of 0.311. In patients with ccRCC, a negative correlation was noted between tumor CD276 expression and PFI. The larger the tumor diameter and the higher the tumor CD276 expression level, the shorter is the PFI.

CD276 as a promising diagnostic and prognostic biomarker for bladder cancer through bioinformatics and clinical research

Objective

To assess CD276 expression and explore its relationship with the clinicopathological characteristics and prognosis of patients with bladder cancer.

Methods

In total, RNA-sequencing data and clinical profiles of 436 bladder cancer cases from The Cancer Genome Atlas (TCGA) were assessed using the University of California Santa Cruz Xena (UCSC) platform. We compared the CD276 levels in cancerous and adjacent normal tissues and used the R software for statistical association with the clinical stage, grade, and survival (the overall survival, disease-specific survival, and progression-free survival). A single-gene GSEA analysis on TCGA-BLCA data was performed to explore potential pathways through which CD276 might influence bladder cancer. Additionally, CD276 expression was analyzed by comparing data from 9 cancerous tissues and 3 adjacent normal tissues in the GEO dataset GSE7476. Furthermore, we analyzed 133 cancerous bladder and adjacent tissue samples from the Soochow University Hospital, collected between January 1, 2016, and September 30, 2022, to assess the CD276 protein expression using immunohistochemistry. We examined the relationship between tumor CD276 levels and clinical outcomes and prognosis of bladder cancer.

Results

Bioinformatic analysis revealed elevated CD276 expression in tumors compared to that in adjacent tissues (p<0.05), correlating with poor survival. GSEA revealed that CD276 was significantly involved in extracellular matrix-related pathways. Immunohistochemistry confirmed CD276 overexpression in tumor tissues, with higher levels linked to advanced pathological grades and worse prognosis.

Conclusion

CD276 is markedly upregulated in bladder cancer and associated with severe pathological features, advanced disease, potential for metastasis, and diminished survival rates. It may promote bladder cancer development and progression by influencing extracellular matrix-related-related pathways, making it a viable diagnostic and prognostic biomarker for bladder cancer.

B7 homolog 3 in pancreatic cancer

Despite advances in cancer treatment, pancreatic cancer (PC) remains a disease with high mortality rates and poor survival outcomes. The B7 homolog 3 (B7-H3) checkpoint molecule is overexpressed among many malignant tumors, including PC, with low or absent expression in healthy tissues. By modulating various immunological and nonimmunological molecular mechanisms, B7-H3 may influence the progression of PC. However, the impact of B7-H3 on the survival of patients with PC remains a subject of debate. Still, most available scientific data recognize this molecule as a suppressive factor to antitumor immunity in PC. Furthermore, it has been demonstrated that B7-H3 stimulates the migration, invasion, and metastasis of PC cells, and enhances resistance to chemotherapy. In preclinical models of PC, B7-H3-targeting monoclonal antibodies have exerted profound antitumor effects by increasing natural killer cell-mediated antibody-dependent cellular cytotoxicity and delivering radioisotopes and cytotoxic drugs to the tumor site. Finally, PC treatment with B7-H3-targeting antibody-drug conjugates and chimeric antigen receptor T cells is being tested in clinical studies. This review provides a comprehensive analysis of all PC-related studies in the context of B7-H3 and points to deficiencies in the current data that should be overcome by future research.

The immune regulatory function of B7-H3 in malignancy: spotlight on the IFN-STAT1 axis and regulation of tumor-associated macrophages

B7-H3 is a member of the B7 superfamily and a putative inhibitory immune checkpoint molecule. Several early-phase clinical trials have reported promising anti-tumor activity and safety of anti-cancer drugs targeting B7-H3, suggesting that it may be a promising target for a potential next-generation immune checkpoint inhibitor. Despite ongoing clinical studies, most B7-H3-targeted drugs being currently investigated rely on direct cytotoxicity as their mechanisms of action rather than modulating its function as an immune checkpoint, at least in part due to its incompletely understood immune regulatory function. Recent studies have begun to elucidate the role of B7-H3 in regulating the tumor microenvironment (TME). Emerging evidence suggests that B7-H3 may regulate the interferon-STAT1 axis in the TME and promote immune suppression. Similarly, increasing evidence shows B7-H3 may be implicated in promoting M1 to M2 polarization of tumor-associated macrophages (TAMs). There is also accumulating evidence suggesting that B7-H3 may play a role in the heterotypic fusion of cancer stem cells and macrophages, thereby promoting tumor invasion and metastasis. Here, we review the recent advances in the understanding of B7-H3 cancer immunobiology with a focus on highlighting its potential role in the interferon priming of TAMs and the heterotypic fusion of TAMs with cancer stem cells and suggest future direction in elucidating its immune checkpoint function.

B7-H3 Expression in Breast Cancer and Brain Metastasis

Brain metastasis is a significant challenge for some breast cancer patients, marked by its aggressive nature, limited treatment options, and poor clinical outcomes. Immunotherapies have emerged as a promising avenue for brain metastasis treatment. B7-H3 (CD276) is an immune checkpoint molecule involved in T cell suppression, which is associated with poor survival in cancer patients. Given the increasing number of clinical trials using B7-H3 targeting CAR T cell therapies, we examined B7-H3 expression across breast cancer subtypes and in breast cancer brain metastases to assess its potential as an interventional target. B7-H3 expression was investigated using immunohistochemistry on tissue microarrays of three clinical cohorts: (i) unselected primary breast cancers (n = 347); (ii) brain metastatic breast cancers (n = 61) and breast cancer brain metastases (n = 80, including a subset of 53 patient-matched breast and brain metastasis cases); and (iii) mixed brain metastases from a range of primary tumours (n = 137). In primary breast cancers, B7-H3 expression significantly correlated with higher tumour grades and aggressive breast cancer subtypes, as well as poorer 5-year survival outcomes. Subcellular localisation of B7-H3 impacted breast cancer-specific survival, with cytoplasmic staining also correlating with a poorer outcome. Its expression was frequently detected in brain metastases from breast cancers, with up to 90% expressing B7-H3. However, not all brain metastases showed high levels of expression, with those from colorectal and renal tumours showing a low frequency of B7-H3 expression (0/14 and 2/16, respectively). The prevalence of B7-H3 expression in breast cancers and breast cancer brain metastases indicates potential opportunities for B7-H3 targeted therapies in breast cancer management.

New Emerging Targets in Cancer Immunotherapy: The Role of B7-H3

Immune checkpoints (ICs) are molecules implicated in the fine-tuning of immune response via co-inhibitory or co-stimulatory signals, and serve to secure minimized host damage. Targeting ICs with various therapeutic modalities, including checkpoint inhibitors/monoclonal antibodies (mAbs), antibody-drug conjugates (ADCs), and CAR-T cells has produced remarkable results, especially in immunogenic tumors, setting a paradigm shift in cancer therapeutics through the incorporation of these IC-targeted treatments. However, the large proportion of subjects who experience primary or secondary resistance to available IC-targeted options necessitates further advancements that render immunotherapy beneficial for a larger patient pool with longer duration of response. B7-H3 (B7 Homolog 3 Protein, CD276) is a member of the B7 family of IC proteins that exerts pleiotropic immunomodulatory effects both in physiologic and pathologic contexts. Mounting evidence has demonstrated an aberrant expression of B7-H3 in various solid malignancies, including tumors less sensitive to current immunotherapeutic options, and has associated its expression with advanced disease, worse patient survival and impaired response to IC-based regimens. Anti-B7-H3 agents, including novel mAbs, bispecific antibodies, ADCs, CAR-T cells, and radioimmunotherapy agents, have exhibited encouraging antitumor activity in preclinical models and have recently entered clinical testing for several cancer types. In the present review, we concisely present the functional implications of B7-H3 and discuss the latest evidence regarding its prognostic significance and therapeutic potential in solid malignancies, with emphasis on anti-B7-H3 modalities that are currently evaluated in clinical trial settings. Better understanding of B7-H3 intricate interactions in the tumor microenvironment will expand the oncological utility of anti-B7-H3 agents and further shape their role in cancer therapeutics.

Bioinformatic Analysis and Clinical Case Studies Identify CD276 as a Promising Diagnostic Biomarker for Clear Cell Renal Cell Carcinoma

OBJECTIVE

This study aimed to explore the relationship between CD276 and clear cell renal carcinoma (ccRCC) and assess the diagnostic value of CD276 in ccRCC.

METHODS

Expression levels of CD276 in ccRCC and para-cancer tissues were compared and analyzed retrospectively using data obtained from TCGA and GEO databases. The clinical data was analyzed prospectively. Immunohistochemistry and RT-PCR analyses were used to analyze the expression of CD276 at the mRNA and protein levels. These analyses compared the expression between ccRCC tissues and para-cancer tissues obtained from 70 patients with ccRCC. Next, ELISA was used to analyze peripheral blood samples from 70 patients with ccRCC and 72 healthy individuals, facilitating the differentiation of ccRCC patients from normal controls. Finally, we utilized the Kaplan-Meier method to generate ROC curves for assessing the diagnostic value of CD276 for ccRCC.

RESULTS

Analysis of TCGA and GEO data revealed that the mRNA expression of CD276 was higher in ccRCC tissues than in para-cancer tissues (P < .05). Clinical validation using IHC and RT-PCR confirmed that the expression of CD276 was higher in ccRCC tissues than in para-cancer tissues, both at the mRNA and protein levels (P < .05). ELISA demonstrated that the expression of CD276 was higher in ccRCC patients than in normal individuals, and patients with a higher pathological grade showed higher expression of CD276 in the peripheral blood than those with a lower pathological grade (P < .05). ROC curves drawn from the above three datasets demonstrated that CD276 had a high diagnostic value for ccRCC (AUC = .894, .795, .938, respectively).

CONCLUSION

The expression of CD276 was higher in ccRCC tissues and positively associated with the pathological grade. Therefore, CD276 may serve as a molecular biomarker for ccRCC prediction.

Exploration of Morphological Features of Clear Cell Renal Cell Carcinoma With PBRM1, SETD2, BAP1, or KDM5C Mutations

The last decade has seen great advances in genomic profiling and prognosis-associated factors of clear cell renal cell carcinoma (RCC), the most common entity in kidney cancer. Following VHL, PBRM1, SETD2, BAP1, and KDM5C have been validated as the most common co-occurring gene mutations in clear cell RCC by multicenter studies. However, the morphological features of clear cell RCC with co-occurring gene mutations remain unclear. In this study, we presented 20 clear cell RCCs that underwent next-generation sequencing, of which 1 tumor was reclassified as ELOC-mutated RCC. PBRM1, SETD2, BAP1, and KDM5C were the most common mutations, following VHL. Morphologically, clear cell RCC with PBRM1 or KDM5C mutation usually displayed a low-grade pattern. Cystic changes and hyalinized stroma were often observed. The Ki67 index was <10%. These observations indicated good prognosis. However, mutated SETD2 may increase the malignancy of clear cell RCC with PBRM1 mutation. Two clear cell RCCs with mutated PBRM1 and SETD2 developed local or distant metastases. Clear cell RCC with BAP1 mutations always had high-grade patterns, and rhabdoid differentiation was also observed, indicating that BAP1 mutation was associated with poor outcomes. Papillary architecture was often a feature of BAP1 mutation, which is uncommon in clear cell RCC. PDL1 was positive in only one tumor with BAP1 mutation, and the positivity rate was limited to 5%. B7H3 was negative in all tumors. Morphologic findings in this small cohort may suggest why PBRM1 mutation does not correlate with decreased survival, whereas BAP1 mutation usually predicts poor outcomes.

Targeting B7-H3-A Novel Strategy for the Design of Anticancer Agents for Extracranial Pediatric Solid Tumors Treatment

Recent scientific data recognize the B7-H3 checkpoint molecule as a potential target for immunotherapy of pediatric solid tumors (PSTs). B7-H3 is highly expressed in extracranial PSTs such as neuroblastoma, rhabdomyosarcoma, nephroblastoma, osteosarcoma, and Ewing sarcoma, whereas its expression is absent or very low in normal tissues and organs. The influence of B7-H3 on the biological behavior of malignant solid neoplasms of childhood is expressed through different molecular mechanisms, including stimulation of immune evasion and tumor invasion, and cell-cycle disruption. It has been shown that B7-H3 knockdown decreased tumor cell proliferation and migration, suppressed tumor growth, and enhanced anti-tumor immune response in some pediatric solid cancers. Antibody-drug conjugates targeting B7-H3 exhibited profound anti-tumor effects against preclinical models of pediatric solid malignancies. Moreover, B7-H3-targeting chimeric antigen receptor (CAR)-T cells demonstrated significant in vivo activity against different xenograft models of neuroblastoma, Ewing sarcoma, and osteosarcoma. Finally, clinical studies demonstrated the potent anti-tumor activity of B7-H3-targeting antibody-radioimmunoconjugates in metastatic neuroblastoma. This review summarizes the established data from various PST-related studies, including in vitro, in vivo, and clinical research, and explains all the benefits and potential obstacles of targeting B7-H3 by novel immunotherapeutic agents designed to treat malignant extracranial solid tumors of childhood.

New frontiers in immune checkpoint B7-H3 (CD276) research and drug development

B7-H3 (CD276), a member of the B7 family of proteins, is a key player in cancer progression. This immune checkpoint molecule is selectively expressed in both tumor cells and immune cells within the tumor microenvironment. In addition to its immune checkpoint function, B7-H3 has been linked to tumor cell proliferation, metastasis, and therapeutic resistance. Furthermore, its drastic difference in protein expression levels between normal and tumor tissues suggests that targeting B7-H3 with drugs would lead to cancer-specific toxicity, minimizing harm to healthy cells. These properties make B7-H3 a promising target for cancer therapy.Recently, important advances in B7-H3 research and drug development have been reported, and these new findings, including its involvement in cellular metabolic reprograming, cancer stem cell enrichment, senescence and obesity, have expanded our knowledge and understanding of this molecule, which is important in guiding future strategies for targeting B7-H3. In this review, we briefly discuss the biology and function of B7-H3 in cancer development. We emphasize more on the latest findings and their underlying mechanisms to reflect the new advances in B7-H3 research. In addition, we discuss the new improvements of B-H3 inhibitors in cancer drug development.

B7 family protein glycosylation: Promising novel targets in tumor treatment

Cancer immunotherapy, including the inhibition of immune checkpoints, improves the tumor immune microenvironment and is an effective tool for cancer therapy. More effective and alternative inhibitory targets are critical for successful immune checkpoint blockade therapy. The interaction of the immunomodulatory ligand B7 family with corresponding receptors induces or inhibits T cell responses by sending co-stimulatory and co-inhibitory signals respectively. Blocking the glycosylation of the B7 family members PD-L1, PD-L2, B7-H3, and B7-H4 inhibited the self-stability and receptor binding of these immune checkpoint proteins, leading to immunosuppression and rapid tumor progression. Therefore, regulation of glycosylation may be the "golden key" to relieve tumor immunosuppression. The exploration of a more precise glycosylation regulation mechanism and glycan structure of B7 family proteins is conducive to the discovery and clinical application of antibodies and small molecule inhibitors.

Understanding the versatile roles and applications of EpCAM in cancers: from bench to bedside

Epithelial cell adhesion molecule (EpCAM) functions not only in physiological processes but also participates in the development and progression of cancer. In recent decades, extensive efforts have been made to decipher the role of EpCAM in cancers. Great advances have been achieved in elucidating its structure, molecular functions, pathophysiological mechanisms, and clinical applications. Beyond its well-recognized role as a biomarker of cancer stem cells (CSCs) or circulating tumor cells (CTCs), EpCAM exhibits novel and promising value in targeted therapy. At the same time, the roles of EpCAM in cancer progression are found to be highly context-dependent and even contradictory in some cases. The versatile functional modules of EpCAM and its communication with other signaling pathways complicate the study of this molecule. In this review, we start from the structure of EpCAM and focus on communication with other signaling pathways. The impacts on the biology of cancers and the up-to-date clinical applications of EpCAM are also introduced and summarized, aiming to shed light on the translational prospects of EpCAM.

Prognostic value of Talin-1 in renal cell carcinoma and its association with B7-H3

METHODS: Talin-1 protein was demonstrated as a potential prognostic marker in renal cell carcinoma (RCC) using bioinformatics analysis. We, therefore, examined the protein expression levels and prognostic significance of Talin-1 with a clinical follow-up in a total of 269 tissue specimens from three important subtypes of RCC and 30 adjacent normal samples using immunohistochemistry. Then, we used combined analysis with B7-H3 to investigate higher prognostic values. RESULTS: The results showed that high membranous and cytoplasmic expression of Talin-1 was significantly associated with advanced nucleolar grade, microvascular invasion, histological tumor necrosis, and invasion to Gerota’s fascia in clear cell RCC (ccRCC). In addition, high membranous and cytoplasmic expression of Talin-1 was found to be associated with significantly poorer disease-specific survival (DSS) and progression-free survival (PFS). Moreover, increased cytoplasmic expression of Talin-1High/B7-H3High compared to the other phenotypes was associated with tumor aggressiveness and progression of the disease, and predicted a worse clinical outcome, which may be an effective biomarker to identify ccRCC patients at high risk of recurrence and metastasis. CONCLUSIONS: Collectively, these observations indicate that Talin-1 is an important molecule involved in the spread and progression of ccRCC when expressed particularly in the cytoplasm and may serve as a novel prognostic biomarker in this subtype. Furthermore, a combined analysis of Talin-1/B7-H3 indicated an effective biomarker to predict the progression of disease and prognosis in ccRCC.

B7-H3 is eligible for predicting clinical outcomes in lung adenocarcinoma patients treated with EGFR tyrosine kinase inhibitors

BACKGROUND

Not all lung adenocarcinoma (LUAD) patients with activating epidermal growth factor receptor (EGFR) mutations respond to tyrosine kinase inhibitors (TKIs) as intended. Thus, biomarkers are needed to identify patients who benefit most from EGFR-targeted therapy. Our previous in vitro data has shown that the co-signal molecule B7-H3 determines EGFR-TKI gefitinib susceptibility of EGFR-mutated LUAD cell lines, based on the potential crosslinking between B7-H3-induced signaling and EGFR signaling.

METHODS

We detected tumoral B7-H3 expression in the original biopsy from 56 treatment-naïve LUAD patients and analyzed the association between high/low B7-H3 expression with the clinical outcomes of first-line anti-EGFR therapy. The main criteria for the analysis of response were overall response rate (ORR), disease control rate (DCR), and progression-free survival (PFS), and the secondary criterion was overall survival (OS).

RESULTS

In the subgroups of B7-H3 high and low expression, the ORR were 16.0% (4/25) and 74.2% (23/31) (p<0.001), and the DCR were 36.0% (9/25) and 87.1% (27/31) (p<0.001), respectively. The PFS of B7-H3 high [median 8.7, 95% confidence interval (CI) 4.0-13.4] was significantly worse than that of B7-H3 low (median not reached) [HR 6.54 (95% CI 2.18-19.60), p=0.001]. The median OS was 15.9 (95% CI 10.0-21.8) months in the B7-H3 high cohort and 25.7 (95% CI 9.0-42.4) months in the B7-H3 low subjects [HR 2.08 (95% CI 1.07-4.02), p=0.03], respectively. Both the univariate and multivariate analyses identified B7-H3 as an independent factor associated with poor PFS (p=0.001, p=0.000) and OS (p=0.03, p=0.015).

CONCLUSION

B7-H3 may serve as a potential biomarker to predict clinical outcomes in EGFR-mutated LUAD patients treated with first-line EGFR-TKIs.

Elevated Expression of the Immune Checkpoint Ligand CD276 (B7-H3) in Urothelial Carcinoma Cell Lines Correlates Negatively with the Cell Proliferation

The cell surface molecule CD276 (B7-H3) is an immune checkpoint antigen. The elevated expression of CD276 on tumors contributes to the suppression of anti-tumor T-cell responses and correlates with poor prognosis.

METHODS

The expression of CD276 was explored in vitro on eight urothelial carcinoma cell lines (UM-UC) in comparison to eight normal urothelial cells (NUCs) by RT-qPCR, Western blotting, and flow cytometry. Cell proliferation was enumerated over consecutive passages. The expression of cancer stem cell markers CD24 and CD44, cytokeratins, and vimentin was investigated by immunofluorescence. The expression of CD276 in bladder tumor samples and metastases was explored by immunohistochemistry.

RESULTS

Expression of CD276 on cell surfaces was elevated on UM-UCs when compared to NUCs. In UM-UCs, CD276 transcripts correlated moderately positive with CD276 protein expression (ρ = 0.660) and strongly positive with CD276 surface-expression (ρ = 0.810). CD276 mRNA expression (ρ = -0.475) and CD276 protein expression (ρ = -0.417) had a significant negative correlation with proliferation, while a significant correlation between proliferation and cell surface expression was not observed in UM-UCs.

CONCLUSION

The expression of CD276 on UM-UC bladder tumor cell surfaces is elevated. Slow proliferating UM-UC cells express more CD276 mRNA and protein than fast proliferating cells. In patients, slow proliferating CD276high tumor (stem) cells may evade immune surveillance. However, cancer therapy targeting CD276 may be effective in the treatment of slow proliferating tumor cells.

Significant co-expression of putative cancer stem cell markers, EpCAM and CD166, correlates with tumor stage and invasive behavior in colorectal cancer

BACKGROUND

The crucial oncogenic role of cancer stem cells (CSCs) in tumor maintenance, progression, drug resistance, and relapse has been clarified in different cancers, particularly in colorectal cancer (CRC). The current study was conducted to evaluate the co-expression pattern and clinical significance of epithelial cell adhesion molecules (EpCAM) and activated leukocyte cell adhesion (CD166 or ALCAM) in CRC patients.

METHODS

This study was carried out on 458 paraffin-embedded CRC specimens by immunohistochemistry on tissue microarray (TMA) slides.

RESULTS

Elevated expression of EpCAM and CD166 was observed in 61.5% (246/427) and 40.5% (164/405) of CRC cases. Our analysis showed a significant positive association of EpCAM expression with tumor size (P = 0.02), tumor stage (P = 0.007), tumor differentiate (P = 0.005), vascular (P = 0.01), neural (P = 0.01), and lymph node (P = 0.001) invasion. There were no significant differences between CD166 expression and clinicopathological parameters. Moreover, the combined analysis demonstrated a reciprocal significant correlation between EpCAM and CD166 expression (P = 0.02). Interestingly, there was a significant positive correlation between EpCAM/CD166 phenotypes expression and tumor stage (P = 0.03), tumor differentiation (P = 0.05), neural, and lymph node invasion (P =0.01).

CONCLUSIONS

The significant correlation of EpCAM and CD166 expression and their association with tumor progression and aggressive behavior is the reason for the suggestion of these two CSC markers as promising targets to promote novel effective targeted-therapy strategies for cancer treatment in the present study.

Overexpression of melanoma-associated antigen A2 has a clinical significance in embryonal carcinoma and is associated with tumor progression

INTRODUCTION

Melanoma-associated antigen A2 (MAGE-A2) is a member of the cancer-testis antigen family differentially overexpressed in a variety of malignancies and is associated with tumor development. However, clinical significance and prognostic value of MAGE-A2 in different histological subtypes of testicular germ cell tumors (TGCTs) have not been explored.

MATERIALS AND METHODS

Here, we aimed to investigate the clinical significance and prognostic impact of MAGE-A2 expression in TGCTs compared to benign tumors as well as adjacent normal tissues and then between seminomas and non-seminomas groups using immunohistochemistry on tissue microarrays.

RESULTS

The results indicated a statistically significant difference between overexpression of MAGE-A2 and histological subtypes of TGCTs. A statistically significant association was found between a high level of nuclear expression of MAGE-A2 protein and advanced pT stage (P = 0.022), vascular invasion (P = 0.037), as well as involvement of rete testis (P = 0.022) in embryonal carcinomas. Increased nuclear expression of MAGE-A2 was observed to be associated with more aggressive behaviors and tumor progression rather than cytoplasmic expression in these cases. Further, high level nuclear expression of MAGE-A2 had shorter disease-specific survival (DSS) or progression-free survival (PFS) compared to patients with moderate and low expression of MAGE-A2, however, without a statistically significant association.

CONCLUSION

Our results confirm that increased nuclear expression of MAGE-A2 has a clinical significance in embryonal carcinomas and is associated with progression of disease. Moreover, MAGE-A2 may act as a potential predictive biomarker for the prognosis in embryonal carcinomas if follow-up period becomes longer. Further investigations for the biological function of MAGE-A2 are required in future studies.

Fibronectin enhances tumor metastasis through B7-H3 in clear cell renal cell carcinoma

B7 homolog 3 (B7‐H3) plays an important role in tumor biology, but the molecular mechanism underlying the role of B7‐H3 in tumor metastasis remains unclear. In this article, our analysis of The Cancer Genome Atlas database suggested that B7‐H3 expression is associated with poor prognosis of patients with clear cell renal cell carcinoma (ccRCC). B7‐H3 knockdown affected the expression of metastasis‐related genes and significantly suppressed the metastasis of ccRCC cells, but it had no significant effect on the proliferation of ccRCC cells. Database analysis revealed a strong positive correlation between B7‐H3 and fibronectin (FN) in ccRCC cells, and further study also confirmed that FN interacts with B7‐H3. Silencing FN expression inhibited the migration and invasion of ccRCC cells, whereas exogenous FN promoted the migration and invasion of ccRCC cells, which was accompanied by activation of kinases [namely, phosphorylated (p)‐phosphoinositide 3‐kinase, p‐protein kinase B, p‐p38 and p‐extracellular regulated protein kinase]. B7‐H3 knockdown abolished the prometastatic effect of FN. In conclusion, our data suggest that B7‐H3 binds to exogenous FN and promotes the metastasis of ccRCC cells.

B7-H3 targeted antibody-based immunotherapy of malignant diseases

Introduction: Recent advances in immuno-oncology and bioengineering have rekindled the interest in monoclonal antibody (mAb)-based immunotherapies for malignancies. Crucial for their success is the identification of tumor antigens (TAs) that can serve as targets. B7-H3, a member of the B7 ligand family, represents such a TA. Although its exact functions and receptor(s) remain unclear, B7-H3 has predominantly a pro-tumorigenic effect mainly by suppressing the anti-tumor functions of T-cells.Areas covered: Initially we present a historical perspective on TA-specific antibodies for diagnosis and treatment of malignancies. Following a description of the TA requirements to be an attractive antibody-based immunotherapy target, we show that B7-H3 fulfills these criteria. We discuss its structure and functions. In a review and pooled analysis, we describe the limited B7-H3 expression in normal tissues and estimate B7-H3 expression frequency in tumors, tumor-associated vasculature and cancer initiating cells (CICs). Lastly, we discuss the association of B7-H3 expression in tumors with poor prognosis.Expert opinion: B7-H3 is an attractive target for mAb-based cancer immunotherapy. B7-H3-targeting strategies are expected to be highly effective and - importantly - safe. To fully exploit the diagnostic and therapeutic potential of B7-H3, its expression in pre-malignant lesions, serum, metastases, and CICs requires further investigation.

Expression patterns of the immune checkpoint ligand CD276 in urothelial carcinoma

BACKGROUND

CD276 is an immune checkpoint molecule. Elevated CD276 expression by urothelial carcinoma is associated with poor prognosis, but little is known about its expression across different tumor stages. We therefore investigated CD276 expression in bladder cancer (BC) cells and in tissue samples of BC stages from pT2 to pT4.

METHODS

CD276 expression was explored in 4 urothelial cancer cell lines and 4 primary normal urothelial cell populations by quantitative RT-PCR, Western blot and flow cytometry. CD276 was investigated in bladder tumors from 98 patients by immunohistochemistry using a score (0-300) incorporating both, staining intensity and area of CD276 staining. Normal appearing urothelium in the bladder of the same patients served as controls.

RESULTS

The urothelial carcinoma cell lines expressed significantly higher levels of CD276 on transcript (p < 0.006), total protein levels (p < 0.005), and on the cell surface (p < 0.02) when compared to normal urothelial cells. In pT2-T4 tumor tissue samples, CD276 was overexpressed (median score 185) when compared to corresponding healthy tissues from the same patients (median score 50; p < 0.001). No significant differences in CD276 expression were recorded in late, locally advanced ≥ pT3a tumors (median score 185) versus organ-confined < pT3a tumors (median score 190), but it was significantly lower in the normal urothelial tissue associated with ≥ pT3a tumors (median score 40) versus < pT3a tumors (median score 80; p < 0.05).

CONCLUSION

CD276 expression is significantly elevated in urothelial carcinoma cells in all stages but varies between individuals considerably. Reduced CD276 expression in normal urothelial cells may imply that these cells would be protected from CD276-mediated immuno therapies.

Low expression of Talin1 is associated with advanced pathological features in colorectal cancer patients

To explore the proper prognostic markers for the likelihood of metastasis in CRC patients. Seventy-seven fresh CRC samples were collected to evaluate the mRNA level of the selected marker using Real-time PCR. Moreover, 648 formalin-fixed paraffin-embedded CRC tissues were gathered to evaluate protein expression by immunohistochemistry (IHC) on tissue microarrays. The results of Real-Time PCR showed that low expression of Talin1 was significantly associated with advanced TNM stage (p = 0.034) as well as gender (p = 0.029) in mRNA levels. Similarly, IHC results indicated that a low level of cytoplasmic expression of Talin1 was significantly associated with advanced TNM stage (p = 0.028) as well as gender (p = 0.009) in CRC patients. Moreover, decreased expression of cytoplasmic Talin1 protein was found to be a significant predictor of worse disease-specific survival (DSS) (p = 0.011) in the univariate analysis. In addition, a significant difference was achieved (p = 0.039) in 5-year survival rates of DSS: 65% for low, 72% for moderate, and 88% for high Talin1 protein expression. Observations showed that lower expression of Talin1 at both the gene and protein level may drive the disparity of CRC patients’ outcomes via worse DSS and provide new insights into the development of progression indicators because of its correlation with increased tumor aggressiveness.