Gliomas are very malignant brain tumors that are difficult to treat. CD47 is an antiphagocytic molecule that binds to SIPRα on phagocytes. It is overexpressed on the plasma membranes of multiple human tumor cell types and is an important diagnostic and prognostic biomarker in many types of cancer. However, the association between CD47 protein expression in glioma tissue and clinicopathological stage has not been investigated in detail. A total of 80 surgical glioma specimens were stained with anti-CD47 antibody to assess the relationship between CD47 protein expression and clinicopathological stage of the glioma. Wound healing assays were performed to analyze the influence of CD47 on the migration and invasion of glioma cells, and near-infrared fluorescence localization assays in a U-87 MG-bearing xenograft model were used to determine the distribution of anti-CD47 antibody in vivo. MTT assays and administration of anti-CD47 to a U251-bearing xenograft model were used to analyze the inhibitory effects of the antibody on gliomas. CD47 expression was higher in high-grade gliomas than in low-grade gliomas, and high CD47 expression was positively correlated with histology and tumor clinicopathological stage. CD47 over-expression promoted the growth and motility of two glioma cell lines (U-87 MG and U251) and a laboratory-developed anti-CD47 antibody accumulated at the glioma site. Proliferation of U251 and U-87 MG cells was not significantly inhibited by the anti-CD47 antibody in vitro, but the antibody significantly inhibited U251 growth in vivo. It also enhanced inhibition capacity by Taxol. Our results suggest that CD47 plays a critical role in the progression of gliomas from stage I to IV and may be a potential target for the treatment of gliomas. CD47 appears to play a critical role in the progression of gliomas from stage I to IV and an anti-CD47 antibody prepared in the laboratory may inhibit the growth of gliomas.
Background: Recombinant human calcineurin B subunit (rhCNB) has been shown to be an immune‐stimulatory protein promoting cytokine production and inducing phenotypic maturation of Dendritic cells (DCs). In vivo, it has good antitumor efficacy, and has potential as an antitumor drug. Exogenous rhCNB was found to be internalized into tumor cells via the Toll‐like receptor 4 (TLR4) complex, but it was not known whether its immuno‐modulatory and antitumor functions involved entry by this same route.Methods: The production and secretion of the cytokines and chemokines in innate immune cells induced by rhCNB were determined by ELISA, and the expression of CD40, CD80, CD86, and MHCII was analyzed by FACs. Experimental Lewis lung cancer (LLC) model was prepared in C57 BL/6 wild‐type (WT) mice, TLR4−/− mice or their littermates by the inoculation of LLCs in their right armpit, and then administrated daily intraperitoneal injections (0.2 mL) of normal saline, rhCNB 20 mg/kg, and rhCNB 40 mg/kg, respectively.Results: Recombinant human calcineurin B subunit promoted the production of antitumor cytokines by innate immune cells, and culture supernatants of rhCNB‐stimulated immune cells induced apoptosis of LLCs. In addition, rhCNB up‐regulated CD40, CD80, CD86, and MHCII expression in macrophages and DCs in TLR4+ cells but failed to do so in TLR4 deficient cells. rhCNB also induced the formation of CD4+ and CD8+T cells in splenocytes from WT mice, but not from TLR4‐deficient littermates. Intraperitoneal administration of WT C57BL/6 mice with rhCNB resulted in a 50% reduction in LLC tumor growth, but failed to inhibit tumor growth in TLR4−/− littermates.Conclusions: The in vivo antitumor and immunomodulatory effects of rhCNB are mediated by the TLR4. This conclusion is important for the further understanding and development of rhCNB as an antitumor drug.
Neuronal apoptosis is an early and critical pathological hallmark of many chronic neurodegenerative diseases, often occurring silently long before the appearance of overt clinical symptoms. In this study, we engineered astrocytes utilizing a dual-biomarker recognition synNotch system (dual-synNotch). This system is designed to specifically identify neuronal apoptosis through the ‘AND Gate’ activation mechanism, which is triggered by the simultaneous sensing of the apoptotic signal phosphatidylserine (PS) and the neuronal signal ganglioside Gt1b. Upon detection of these neuronal apoptotic signals, the synNotch receptors are activated, inducing the expression of two key molecules: secreted Gaussia luciferase (GLuc), a highly detectable reporter that can cross the blood–brain barrier (BBB), and brain-derived neurotrophic factor (BDNF), a neuroprotective molecule that promotes neuronal survival by inhibiting apoptosis and enhancing memory and cognitive function. This engineered system effectively converts and amplifies early, imperceptible neuronal apoptotic signals into detectable outputs, enabling convenient in vitro monitoring and diagnosis. Therefore, it represents a promising strategy for the early detection and intervention of neurodegenerative diseases associated with neuronal apoptosis.