The anti-apoptotic effect on cancer-associated fibroblasts of B7-H3 molecule enhancing the cell invasion and metastasis in renal 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.

CXCL3/TGF-β-mediated crosstalk between CAFs and tumor cells augments RCC progression and sunitinib resistance

Cancer-associated fibroblasts (CAFs) play a significant role in tumor development and treatment failure, yet the precise mechanisms underlying their contribution to renal cell carcinoma (RCC) remains underexplored. This study explored the interaction between CAFs and tumor cells, and related mechanisms. CAFs isolated from tumor tissues promoted the tumor progression and drugs resistance both in vivo and in vitro. Mechanistically, chemokine (C-X-C motif) ligand (CXCL) 3 secreted from CAFs mediated its effects. CXCL3 activated its receptor CXCR2 to active the downstream ERK1/2 signaling pathway, subsequently promoting epithelial-mesenchymal transition and cell stemness. Blocking the crosstalk between CAFs and tumor cells by CXCR2 inhibitor SB225002 attenuated the functions of CAFs. Furthermore, Renca cells facilitated the transformation of normal interstitial fibroblasts (NFs) into CAFs and the expression of CXCL3 through TGF-β-Smad2/3 signaling pathway. In turn, transformed NFs promoted the tumor progression and drug resistance of RCC. These findings may constitute potential therapeutic strategies for RCC treatment.

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.

B7-H3 is associated with the armored-cold phenotype and predicts poor immune checkpoint blockade response in melanoma

Melanoma is the most suitable tumor type for immunotherapy, but not all melanoma patients could respond to immunotherapy. B7 homolog 3 (B7-H3) belongs to the B7 family and is overexpressed in a number of malignant tumors, but the expression pattern of B7-H3 in melanoma has not been well summarized. The expression of B7-H3 was investigated in melanoma and its correlations with features of the tumor microenvironment (TME) by using various public databases, including the Cancer Genome Atlas (TCGA), the GEPIA, and the Human Protein Atlas databases. In addition, the in-house melanoma tissue microarray was applied to validate the results from public databases. Based on the public and in-house cohorts, we found that B7-H3 was overexpressed in melanoma tumor tissues and high B7-H3 expression was related to poor clinical outcome. Moreover, B7-H3 was negatively correlated with levels of tumor-infiltrating lymphocytes (TILs) and positively correlated with collagen infiltration. With clinical translational value, the predictive value of B7-H3 for conventional immunotherapy was detected using the Kaplan-Meier plotter tool, and the results showed that melanoma patients with high B7-H3 expression were insensitive to anti-PD-1 and anti-CTLA-4 immunotherapy. In conclusion, we first investigate the expression of B7-H3 in melanoma and its correlations with the TME features, and indicate B7-H3 as a promising therapeutic target in melanoma patients that are insensitive to conventional immunotherapy.

A promising target for breast cancer: B7-H3

Breast cancer (BC) is the second-leading factor of mortality for women globally and is brought on by a variety of genetic and environmental causes. The conventional treatments for this disease have limitations, making it difficult to improve the lifespan of breast cancer patients. As a result, extensive research has been conducted over the past decade to find innovative solutions to these challenges. Targeting of the antitumor immune response through the immunomodulatory checkpoint protein B7 family has revolutionized cancer treatment and led to intermittent patient responses. B7-H3 has recently received attention because of its significant demodulation and its immunomodulatory effects in many cancers. Uncontrolled B7-H3 expression and a bad outlook are strongly associated, according to a substantial body of cancer research. Numerous studies have shown that BC has significant B7-H3 expression, and B7-H3 induces an immune evasion phenotype, consequently enhancing the survival, proliferation, metastasis, and drug resistance of BC cells. Thus, an innovative target for immunotherapy against BC may be the B7-H3 checkpoint.In this review, we discuss the structure and regulation of B7-H3 and its double costimulatory/coinhibitory function within the framework of cancer and normal physiology. Then we expound the malignant behavior of B7-H3 in BC and its role in the tumor microenvironment (TME) and finally focus on targeted drugs against B7-H3 that have opened new therapeutic opportunities in BC.

High B7-H3 expression with low PD-L1 expression identifies armored-cold tumors in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is generally regarded as the most aggressive subtype among breast cancers, but exhibits higher chemotherapeutic and immunotherapeutic responses due to its unique immunogenicity. Thus, appropriate discrimination of subtypes is critical for guiding therapeutic options in clinical practice. In this research, using multiple in-house and public cohorts, we investigated the expression features and immuno-correlations of B7-H3 in breast cancer and checked the anti-tumor effect of the B7-H3 monoclonal antibody in a mouse model. We also developed a novel classifier combining B7-H3 and PD-L1 expression in TNBC. B7-H3 was revealed to be related to immuno-cold features and accumulated collagen in TNBC. In addition, targeting B7-H3 using the monoclonal antibody significantly suppressed mouse TNBC growth, reversed the armored-cold phenotype, and also boosted anti-PD-1 immunotherapy. In addition, patients with B7-H3 high and PD-L1 low expression showed the lowest anti-tumor immune infiltration, the highest collagen level, and the lowest therapeutic responses to multiple therapies, which mostly belong to armored-cold tumors. Overall, this research provides a novel subtyping strategy based on the combination of B7-H3/PD-L1 expression, which leads to a novel approach for the management of TNBC.

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.

B7-H3 in Brain Malignancies: Immunology and Immunotherapy

The immune checkpoint B7-H3 (CD276), a member of the B7 family with immunoregulatory properties, has been identified recently as a novel target for immunotherapy for refractory blood cancers and solid malignant tumors. While research on B7-H3 in brain malignancies is limited, there is growing interest in exploring its therapeutic potential in this context. B7-H3 plays a crucial role in regulating the functions of immune cells, cancer-associated fibroblasts, and endothelial cells within the tumor microenvironment, contributing to the creation of a pro-tumorigenic milieu. This microenvironment promotes uncontrolled cancer cell proliferation, enhanced metabolism, increased cancer stemness, and resistance to standard treatments. Blocking B7-H3 and terminating its immunosuppressive function is expected to improve anti-tumor immune responses and, in turn, ameliorate the progression of tumors. Results from preclinical or observative studies and early-phase trials targeting B7-H3 have revealed promising anti-tumor efficacy and acceptable toxicity in glioblastoma (GBM), diffuse intrinsic pontine glioma (DIPG), medulloblastoma, neuroblastoma, craniopharyngioma, atypical teratoid/rhabdoid tumor, and brain metastases. Ongoing clinical trials are now investigating the use of CAR-T cell therapy and antibody-drug conjugate therapy, either alone or in combination with standard treatments or other therapeutic approaches, targeting B7-H3 in refractory or recurrent GBMs, DIPGs, neuroblastomas, medulloblastomas, ependymomas, and metastatic brain tumors. These trials hold promise for providing effective treatment options for these challenging intracranial malignancies in both adult and pediatric populations.

B7-H3 in Pediatric Tumors: Far beyond Neuroblastoma

B7-H3 is a 4Ig transmembrane protein that emerged as a tumor-associated antigen in neuroblastoma. It belongs to the B7 family, shows an immunoregulatory role toward NK and T cells, and, therefore, has been included in the growing family of immune checkpoints. Besides neuroblastoma, B7-H3 is expressed by many pediatric cancers including tumors of the central nervous system, sarcomas, and acute myeloid leukemia. In children, particularly those affected by solid tumors, the therapeutic protocols are aggressive and cause important life-threatening side effects. Moreover, despite the improved survival observed in the last decade, a relevant number of patients show therapy resistance and fatal relapses. Immunotherapy represents a new frontier in the cure of cancer patients and the targeting of tumor antigens or immune checkpoints blockade showed exciting results in adults. In this encouraging scenario, researchers and clinicians are exploring the possibility to use immunotherapeutics targeting B7-H3; these include mAbs and chimeric antigen receptor T-cells (CAR-T). These tools are rapidly evolving to improve the efficacy and decrease the unwanted side effects; drug-conjugated mAbs, bi-tri-specific mAbs or CAR-T, and, very recently, NK cell engagers (NKCE), tetra-specific molecules engaging a tumor-associated antigen and NK cells, have been generated. Preclinical data are promising, and clinical trials are ongoing. Hopefully, the B7-H3 targeting will provide important benefits to cancer patients.

Modulation of the antitumor immune response by cancer-associated fibroblasts: mechanisms and targeting strategies to hamper their immunosuppressive functions

Cancer-associated fibroblasts (CAFs) are highly heterogeneous players that shape the tumor microenvironment and influence tumor progression, metastasis formation, and response to conventional therapies. During the past years, some CAFs subsets have also been involved in the modulation of immune cell functions, affecting the efficacy of both innate and adaptive anti-tumor immune responses. Consequently, the implication of these stromal cells in the response to immunotherapeutic strategies raised major concerns. In this review, current knowledge of CAFs origins and heterogeneity in the tumor stroma, as well as their effects on several immune cell populations that explain their immunosuppressive capabilities are summarized. The current development of therapeutic strategies for targeting this population and their implication in the field of cancer immunotherapy is also highlighted.

Immune checkpoint of B7-H3 in cancer: from immunology to clinical immunotherapy

Immunotherapy for cancer is a rapidly developing treatment that modifies the immune system and enhances the antitumor immune response. B7-H3 (CD276), a member of the B7 family that plays an immunoregulatory role in the T cell response, has been highlighted as a novel potential target for cancer immunotherapy. B7-H3 has been shown to play an inhibitory role in T cell activation and proliferation, participate in tumor immune evasion and influence both the immune response and tumor behavior through different signaling pathways. B7-H3 expression has been found to be aberrantly upregulated in many different cancer types, and an association between B7-H3 expression and poor prognosis has been established. Immunotherapy targeting B7-H3 through different approaches has been developing rapidly, and many ongoing clinical trials are exploring the safety and efficacy profiles of these therapies in cancer. In this review, we summarize the emerging research on the function and underlying pathways of B7-H3, the expression and roles of B7-H3 in different cancer types, and the advances in B7-H3-targeted therapy. Considering different tumor microenvironment characteristics and results from preclinical models to clinical practice, the research indicates that B7-H3 is a promising target for future immunotherapy, which might eventually contribute to an improvement in cancer immunotherapy that will benefit patients.

Single-cell and spatial analysis reveal interaction of FAP+ fibroblasts and SPP1+ macrophages in colorectal cancer

Colorectal cancer (CRC) is among the most common malignancies with limited treatments other than surgery. The tumor microenvironment (TME) profiling enables the discovery of potential therapeutic targets. Here, we profile 54,103 cells from tumor and adjacent tissues to characterize cellular composition and elucidate the potential origin and regulation of tumor-enriched cell types in CRC. We demonstrate that the tumor-specific FAP⁺ fibroblasts and SPP1⁺ macrophages were positively correlated in 14 independent CRC cohorts containing 2550 samples and validate their close localization by immuno-fluorescent staining and spatial transcriptomics. This interaction might be regulated by chemerin, TGF-β, and interleukin-1, which would stimulate the formation of immune-excluded desmoplasic structure and limit the T cell infiltration. Furthermore, we find patients with high FAP or SPP1 expression achieved less therapeutic benefit from an anti-PD-L1 therapy cohort. Our results provide a potential therapeutic strategy by disrupting FAP⁺ fibroblasts and SPP1⁺ macrophages interaction to improve immunotherapy.

Tumour microenvironment profiling during colorectal cancer progression may enable the discovery of therapeutic targets. Here, single cell and spatial RNA sequencing of tumour and adjacent normal tissues reveals an interaction between FAP⁺ fibroblasts and SPP1⁺ macrophages that could be disrupted as an immunotherapy strategy.

B7-H3 inhibits apoptosis of gastric cancer cell by interacting with Fibronectin

Anti-apoptosis has been widely accepted as a hallmark of malignancy. B7-H3, a type I transmembrane protein, plays a key role in anti-apoptosis and immune escape, but its regulation during cancer development remains unclear. To investigate how the effect of anti-apoptosis is regulated by B7-H3 in gastric cancer, we stably knocked down B7-H3 gene by shRNA in MGC-803 and MKN-45 cells. The correlation between B7-H3 and Fibronectin (FN) expression were investigated by bioinformatics in public data from TCGA (The Cancer Genome Atlas). Here, we reported that B7-H3 expression is positively correlated with FN in clinical gastric cancer samples, and B7-H3 promoted adhesion and inhibited apoptosis of gastric cancer cell through an FN-dependent pathway. Mechanistically, B7-H3 interacted with FN and subsequently activated PI3K/AKT signaling pathway, a critical mediator of oncogenic signaling. In addition, exogenous FN could inhibit the expression of pro-apoptosis-related proteins such as Caspase 3, Caspase 8, Caspase 9, Bax , p53, Apaf-1 and Cleaved PARP, and upregulated the levels of signal molecule p-PI3K, p-AKT and anti-apoptotic proteins Bcl-2 in B7-H3^high group, as compared with those in B7-H3^low group. In conclusion, we here for the first time revealed that B7-H3 inhibits apoptosis of gastric cancer cell through regulation of FN-mediated PI3K/AKT signaling pathways.

The role of B7-H3 in tumors and its potential in clinical application

B7-H3 (CD276 molecule) is an immune checkpoint from the B7 family of molecules that acts more as a co-inhibitory molecule to promote tumor progression. It is abnormally expressed on tumor cells and can be induced to express on antigen-presenting cells (APCs) including dendritic cells (DCs) and macrophages. In the tumor microenvironment (TME), B7-H3 promotes tumor progression by impairing T cell response, promoting the polarization of tumor-associated macrophages (TAMs) to M2, inhibiting the function of DCs, and promoting the migration and invasion of cancer-associated fibroblasts (CAFs). In addition, through non-immunological functions, B7-H3 promotes tumor cell proliferation, invasion, metastasis, resistance, angiogenesis, and metabolism, or in the form of exosomes to promote tumor progression. In this process, microRNAs can regulate the expression of B7-H3. B7-H3 may serve as a potential biomarker for tumor diagnosis and a marker of poor prognosis. Immunotherapy targeting B7-H3 and the combination of B7-H3 and other immune checkpoints have shown certain efficacy. In this review, we summarized the basic characteristics of B7-H3 and its mechanism to promote tumor progression by inducing immunosuppression and non-immunological functions, as well as the potential clinical applications of B7-H3 and immunotherapy based on B7-H3.

[Preliminary study on the effect of B7H3 interaction with fibronectin on apoptosis of human chronic myeloid leukemia cells]

Objective: To explore the effect of the interaction between B7H3 and fibronectin (FN) on the apoptosis of human chronic myeloid leukemia K562 cells. Methods: The expression of B7H3 molecules in K562 cells was detected using flow cytometry and B7H3 overexpressing cells were constructed. The interaction between B7H3 and FN was detected using the co-immunoprecipitation technology. After adding exogenous FN, cell experiments were performed to detect changes in adhesion and cell apoptosis. The changes in apoptosis-related proteins and PI3K/AKT signaling pathway were detected using Western blot. Results: The expression of B7H3 was low in K562, and the cell line K562 OE (overexpression) -B7H3 and the control cell line K562 NC (negative control) -B7H3 were obtained after lentivirus transfection. There is an interaction between B7H3 and FN (P=0.036) , and this interaction promoted cell adhesion (P<0.05) , inhibited cell apoptosis (P<0.05) , and activated the PI3K/AKT signaling pathway (P<0.05) . Conclusion: B7H3 interacts with FN to promote cell adhesion and may inhibit K562 cell apoptosis by activating the PI3K/AKT signaling pathway.

Crosstalk between cancer-associated fibroblasts and immune cells in the tumor microenvironment: new findings and future perspectives

Cancer-associated fibroblasts (CAFs), a stromal cell population with cell-of-origin, phenotypic and functional heterogeneity, are the most essential components of the tumor microenvironment (TME). Through multiple pathways, activated CAFs can promote tumor growth, angiogenesis, invasion and metastasis, along with extracellular matrix (ECM) remodeling and even chemoresistance. Numerous previous studies have confirmed the critical role of the interaction between CAFs and tumor cells in tumorigenesis and development. However, recently, the mutual effects of CAFs and the tumor immune microenvironment (TIME) have been identified as another key factor in promoting tumor progression. The TIME mainly consists of distinct immune cell populations in tumor islets and is highly associated with the antitumor immunological state in the TME. CAFs interact with tumor-infiltrating immune cells as well as other immune components within the TIME via the secretion of various cytokines, growth factors, chemokines, exosomes and other effector molecules, consequently shaping an immunosuppressive TME that enables cancer cells to evade surveillance of the immune system. In-depth studies of CAFs and immune microenvironment interactions, particularly the complicated mechanisms connecting CAFs with immune cells, might provide novel strategies for subsequent targeted immunotherapies. Herein, we shed light on recent advances regarding the direct and indirect crosstalk between CAFs and infiltrating immune cells and further summarize the possible immunoinhibitory mechanisms induced by CAFs in the TME. In addition, we present current related CAF-targeting immunotherapies and briefly describe some future perspectives on CAF research in the end.

Clinical Research on the Mechanisms Underlying Immune Checkpoints and Tumor Metastasis

This study highlights aspects of the latest clinical research conducted on the relationship between immune checkpoints and tumor metastasis. The overview of each immune checkpoint is divided into the following three sections: 1) structure and expression; 2) immune mechanism related to tumor metastasis; and 3) clinical research related to tumor metastasis. This review expands on the immunological mechanisms of 17 immune checkpoints, including TIM-3, CD47, and OX-40L, that mediate tumor metastasis; evidence shows that most of these immune checkpoints are expressed on the surface of T cells, which mainly exert immunomodulatory effects. Additionally, we have summarized the roles of these immune checkpoints in the diagnosis and treatment of metastatic tumors, as these checkpoints are considered common predictors of metastasis in various cancers such as prostate cancer, non-Hodgkin lymphoma, and melanoma. Moreover, certain immune checkpoints can be used in synergy with PD-1 and CTLA-4, along with the implementation of combination therapies such as LIGHT-VTR and anti-PD-1 antibodies. Presently, most monoclonal antibodies generated against immune checkpoints are under investigation as part of ongoing preclinical or clinical trials conducted to evaluate their efficacy and safety to establish a better combination treatment strategy; however, no significant progress has been made regarding monoclonal antibody targeting of CD28, VISTA, or VTCN1. The application of immune checkpoint inhibitors in early stage tumors to prevent tumor metastasis warrants further evidence; the immune-related adverse events should be considered before combination therapy. This review aims to elucidate the mechanisms of immune checkpoint and the clinical progress on their use in metastatic tumors reported over the last 5 years, which may provide insights into the development of novel therapeutic strategies that will assist with the utilization of various immune checkpoint inhibitors.

Signaling pathways in cancer-associated fibroblasts and targeted therapy for cancer

To flourish, cancers greatly depend on their surrounding tumor microenvironment (TME), and cancer-associated fibroblasts (CAFs) in TME are critical for cancer occurrence and progression because of their versatile roles in extracellular matrix remodeling, maintenance of stemness, blood vessel formation, modulation of tumor metabolism, immune response, and promotion of cancer cell proliferation, migration, invasion, and therapeutic resistance. CAFs are highly heterogeneous stromal cells and their crosstalk with cancer cells is mediated by a complex and intricate signaling network consisting of transforming growth factor-beta, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin, mitogen-activated protein kinase, Wnt, Janus kinase/signal transducers and activators of transcription, epidermal growth factor receptor, Hippo, and nuclear factor kappa-light-chain-enhancer of activated B cells, etc., signaling pathways. These signals in CAFs exhibit their own special characteristics during the cancer progression and have the potential to be targeted for anticancer therapy. Therefore, a comprehensive understanding of these signaling cascades in interactions between cancer cells and CAFs is necessary to fully realize the pivotal roles of CAFs in cancers. Herein, in this review, we will summarize the enormous amounts of findings on the signals mediating crosstalk of CAFs with cancer cells and its related targets or trials. Further, we hypothesize three potential targeting strategies, including, namely, epithelial-mesenchymal common targets, sequential target perturbation, and crosstalk-directed signaling targets, paving the way for CAF-directed or host cell-directed antitumor therapy.

Anti-Metastatic Effects of Plant Sap-Derived Extracellular Vesicles in a 3D Microfluidic Cancer Metastasis Model

Natural medicinal plants have attracted considerable research attention for their potential as effective drugs. The roots, leaves and stems of the plant, Dendropanax morbifera, which is endemic to southern regions of Asia, have long been used as a folk medicine to treat variety of diseases. However, the sap of this plant has not been widely studied and its bioactive properties have yet to be clearly elucidated. Here, we isolated extracellular vesicles from D. morbifera sap with the goal of improving the intracellular delivery efficiency and clinical effectiveness of bioactive compounds in D. morbifera sap. We further investigated the anti-metastatic effects of D. morbifera sap-derived extracellular vesicles (DMS-EVs) using a cancer metastasis model based on 3D microfluidic system that closely mimics the in vivo tumor environment. We found that DMS-EVs exerted a concentration-dependent suppressive effect on cancer-associated fibroblasts (CAFs), which are important mediators of cancer metastasis. DMS-EVs also altered expression level of genes, especially growth factor and extracellular matrix (ECM)-related genes, including integrin and collagen. Our findings suggest that DMS-EVs can act as anti-CAF agents to reduce CAFs in the tumor microenvironment. They further indicate the utility of our 3D microfluidic model for various drug-screening assays as a potential alternative to animal testing for use in validating therapeutic effects on cancer metastasis.

B7-H3 Regulates Glioma Growth and Cell Invasion Through a JAK2/STAT3/Slug-Dependent Signaling Pathway

Purpose

The aim of this study was to explore the potential role of B7-H3 in malignant glioma progression and identify an innovative approach in clinical glioma therapy.

Methods

The protein expression of B7-H3 in high- and low-grade tumor tissues from glioma patients was assessed by immunohistochemistry. The proliferative and invasive ability of B7-H3-overexpressing or knockout glioma cells was analyzed in vitro and in vivo by CCK-8 assay and an orthotopic mouse glioma model, respectively. Activation of the JAK2/STAT3/Slug signaling pathway and epithelial-mesenchymal transition (EMT) was examined by Western blotting and immunofluorescence. The anticancer effects of napabucasin (NAP) and temozolomide (TMZ) were analyzed in an orthotopic mouse glioma model.

Results

The expression of B7-H3 was higher in high-grade than in low-grade tumor tissues from glioma patients. In line with this, overexpression of B7-H3 enhanced glioma cell proliferation, induced sustained glioma growth, and promoted glioma cell invasion in vitro and in vivo. Moreover, these effects were mediated through the activation of the JAK2/STAT3/Slug signaling pathway in B7-H3 overexpression glioma cells. We also found that B7-H3 induced EMT processes through downregulation of E-cadherin and upregulation of MMP-2/-9 expression, resulting in enhanced invasion of glioma cells. Finally, we show that the combination of NAP and TMZ significantly suppressed glioma growth and glioma cell invasion, both in vitro and in vivo.

Conclusion

B7-H3 overexpression facilitated sustained glioma growth and promoted glioma cell invasion through a JAK2/STAT3/Slug-dependent signaling pathway. Application of the STAT3 inhibitor NAP significantly suppressed glioma growth and invasion, and has potential as a therapeutic strategy for the treatment of glioma.