B7 homologue 3 as a prognostic biomarker and potential therapeutic target in gastrointestinal tumors

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.

Establishment of a pathomic-based machine learning model to predict CD276 (B7-H3) expression in colon cancer

CD276 is a promising prognostic indicator and an attractive therapeutic target in various malignancies. However, current methods for CD276 detection are time-consuming and expensive, limiting extensive studies and applications of CD276. We aimed to develop a pathomic model for CD276 prediction from H&E-stained pathological images, and explore the underlying mechanism of the pathomic features by associating the pathomic model with transcription profiles. A dataset of colon adenocarcinoma (COAD) patients was retrieved from the Cancer Genome Atlas (TCGA) database. The dataset was divided into the training and validation sets according to the ratio of 8:2 by a stratified sampling method. Using the gradient boosting machine (GBM) algorithm, we established a pathomic model to predict CD276 expression in COAD. Univariate and multivariate Cox regression analyses were conducted to assess the predictive performance of the pathomic model for overall survival in COAD. Gene Set Enrichment Analysis (GESA) was performed to explore the underlying biological mechanisms of the pathomic model. The pathomic model formed by three pathomic features for CD276 prediction showed an area under the curve (AUC) of 0.833 (95%CI: 0.784-0.882) in the training set and 0.758 (95%CI: 0.637-0.878) in the validation set, respectively. The calibration curves and Hosmer-Lemeshow goodness of fit test showed that the prediction probability of high/low expression of CD276 was in favorable agreement with the real situation in both the training and validation sets (P=0.176 and 0.255, respectively). The DCA curves suggested that the pathomic model acquired high clinical benefit. All the subjects were categorized into high pathomic score (PS) (PS-H) and low PS (PS-L) groups according to the cutoff value of PS. Univariate and multivariate Cox regression analysis indicated that PS was a risk factor for overall survival in COAD. Furthermore, through GESA analysis, we found several immune and inflammatory-related pathways and genes were associated with the pathomic model. We constructed a pathomics-based machine learning model for CD276 prediction directly from H&E-stained images in COAD. Through integrated analysis of the pathomic model and transcriptomics, the interpretability of the pathomic model provide a theoretical basis for further hypothesis and experimental research.

B7-H3 regulates anti-tumor immunity and promotes tumor development in colorectal cancer

Colorectal cancer (CRC) is a common malignant tumor of the gastrointestinal tract and one of the most common causes of cancer-related deaths worldwide. Immune checkpoint inhibitors have become a milestone in many cancer treatments with significant curative effects. However, its therapeutic effect on colorectal cancer is still limited. B7-H3 is a novel immune checkpoint molecule of the B7/CD28 family and is overexpressed in a variety of solid tumors including colorectal cancer. B7-H3 was considered as a costimulatory molecule that promotes anti-tumor immunity. However, more and more studies support that B7-H3 is a co-inhibitory molecule and plays an important immunosuppressive role in colorectal cancer. Meanwhile, B7-H3 promoted metabolic reprogramming, invasion and metastasis, and chemoresistance in colorectal cancer. Therapies targeting B7-H3, including monoclonal antibodies, antibody drug conjugations, and chimeric antigen receptor T cells, have great potential to improve the prognosis of colorectal cancer patients.

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.

B7 Family Members in Pancreatic Ductal Adenocarcinoma: Attractive Targets for Cancer Immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with a five-year survival rate of approximately 5-10%. The immune checkpoint blockade represented by PD-1/PD-L1 inhibitors has been effective in a variety of solid tumors but has had little clinical response in pancreatic cancer patients. The unique suppressive immune microenvironment is the primary reason for this outcome, and it is essential to identify key targets to remodel the immune microenvironment. Some B7 family immune checkpoints, particularly PD-L1, PD-L2, B7-H3, B7-H4, VISTA and HHLA2, have been identified as playing a significant role in the control of tumor immune responses. This paper provides a comprehensive overview of the recent research progress of some members of the B7 family in pancreatic cancer, which revealed that they can be involved in tumor progression through immune-dependent and non-immune-dependent pathways, highlighting the mechanisms of their involvement in tumor immune escape and assessing the prospects of their clinical application. Targeting B7 family immune checkpoints is expected to result in novel immunotherapeutic treatments for patients with pancreatic cancer.