The recent impressive clinical responses to antibody-based immunotherapy have prompted the identification of clinically relevant tumor antigens that can serve as targets in solid tumors. Among them, B7-H3, a member of the B7 ligand family, represents an attractive target for antibody-based immunotherapy, it is overexpressed on differentiated malignant cells and cancer-initiating cells, with limited heterogeneity, and high frequency (60% of 25,000 tumor samples) in many different cancer types, but has a limited expression at low level in normal tissues. In nonmalignant tissues, B7-H3 has a predominantly inhibitory role in adaptive immunity, suppressing T-cell activation and proliferation. In malignant tissues, B7-H3 inhibits tumor antigen–specific immune responses, leading to a protumorigenic effect. B7-H3 also has nonimmunologic protumorigenic functions, such as promoting migration and invasion, angiogenesis, chemoresistance, and endothelial-to-mesenchymal transition, as well as affecting tumor cell metabolism. As a result, B7-H3 expression in tumors is associated with poor prognosis. Although experimental B7-H3 silencing reduces cancer cell malignant potential, there has been limited emphasis on the development of B7-H3–blocking antibodies, most likely because the B7-H3 receptor remains unknown. Instead, many antibody-based strategies utilizing distinct effector mechanisms to target B7-H3–expressing cancer cells have been developed. These strategies have demonstrated potent antitumor activity and acceptable safety profiles in preclinical models. Ongoing clinical trials are assessing their safety and efficacy in patients. Identification of the B7-H3 receptor will improve our understanding of its role in tumor immunity, and will suggest rational strategies to develop blocking antibodies, which may enhance the therapeutic efficacy of tumor immunity.
Highlights d Molecular and clinical hallmarks of tRCC are defined via analysis of 152 samples d tRCC genomic alterations are rare aside from MiT/TFE fusions and 9p21.3 deletions d tRCCs display increased NRF2 pathway activation compared with other RCC subtypes d Immunotherapy may be active in some tRCCs
Radiotherapy (RT) is a key treatment for prostate cancer. However, RT resistance can contribute to treatment failure. Prostate cancer stem cells (PCSCs) are radioresistant. We recently found that fractionated irradiation (FIR) upregulates expression of the immune checkpoint B7-H3 (CD276) on PCSCs and bulk cells in each prostate cancer cell line tested. These findings prompted us to investigate whether B7-H3 targeting chimeric antigen receptor (CAR) T cells, which may abrogate function of an immune checkpoint and mediate lysis of targeted cells, can target RT-resistant PCSCs in vitro and in vivo. B7-H3 expression is naturally higher on PCSCs than bulk prostate cancer cells and cytotoxicity of B7-H3 CAR T cells to PCSCs is more potent than to bulk prostate cancer cells. Furthermore, FIR significantly upregulates B7-H3 expression on PCSCs and bulk prostate cancer cells. The duration of FIR or single-dose irradiation-induced further upregulation of B7-H3 on bulk prostate cancer cells and PCSCs lasts for up to 3 days. B7-H3 CAR T-cell cytotoxicity against FIR-resistant PCSCs at a low effector to target ratio of 1:1 was assessed by flow cytometry and sphere formation assays. Further upregulation of B7-H3 expression by FIR made PCSCs even more sensitive to B7-H3 CAR T-cellmediated killing. Consequently, the FIR and B7-H3 CAR T-cell therapy combination is much more effective than FIR or CAR T cells alone in growth inhibition of hormone-insensitive prostate cancer xenografts in immunodeficient mice. Our work provides a sound basis for further development of this unique combinatorial model of RT and B7-H3 CAR T-cell therapy for prostate cancer.Significance: We demonstrate that FIR significantly upregulates B7-H3 expression by RT-resistant PCSCs and bulk cells; cytotoxicity of B7-H3 CAR T cells to FIR-treated PCSCs is potent and results in significantly improved antitumor efficacy in mice.
Covalent organic frameworks (COFs) have emerged as versatile, functional materials comprised of low-cost molecular building blocks. The permanent porosity, long-range order, and high surface area of 3D-COFs permit co-crystallization with other materials driven by supramolecular interactions. We designed a new subphthalocyanine-based 3-D covalent organic framework (NEUCOF1) capable of forming co-crystals with fullerene (C60) via periodic ball-and-socket binding motifs. The high co-crystalline surface area and long-range order of NEUCOF1 eliminates the typical surface area vs. structural order trade-off in organic photovoltaics (OPVs). We used plane-wave density functional theory (PBE) to minimize NEUCOF1 and NEUCOF1-C60 co-crystals and determine their electronic band structures. Molecular dynamics (MD) simulations showed that NEUCOF1-C60 is likely to be stable up to 350 K. The band structures at 0 and 350 K suggest that charge transfer to the C60 acceptors is favorable and that directional charge transport is possible for these co-crystalline OPVs.File list (1) download file view on ChemRxiv COF-JPC_C-resubmit1-final.docx (44.35 MiB)
IMPORTANCEAlthough typically impressive, objective responses to immune checkpoint inhibitors (ICIs) occur in only 12.5% of patients with advanced cancer. The majority of patients do not respond due to cell-intrinsic resistance mechanisms, including human leukocyte antigen (HLA) class I antigen-processing machinery (APM) defects. The APM defects, which have a negative effect on neoantigen presentation to cytotoxic T lymphocytes (CTLs), are present in the majority of malignant tumors. These defects are caused by gene variations in less than 25% of cases and by dysregulated signaling and/or epigenetic changes in most of the remaining cases, making them frequently correctable. This narrative review summarizes the growing clinical evidence that chemotherapy, targeted therapies, and, to a lesser extent, radiotherapy can correct HLA class I APM defects in cancer cells and improve responses to ICIs.OBSERVATIONS Most chemotherapeutics enhance HLA class I APM component expression and function in cancer cells, tumor CTL infiltration, and responses to ICIs in preclinical and clinical models. Despite preclinical evidence, radiotherapy does not appear to upregulate HLA class I expression in patients and does not enhance the efficacy of ICIs in clinical settings. The latter findings underscore the need to optimize the dose and schedule of radiation and timing of ICI administration to maximize their immunogenic synergy. By increasing DNA and chromatin accessibility, epigenetic agents (histone deacetylase inhibitors, DNA methyltransferase inhibitors, and EZH2 inhibitors) enhance HLA class I APM component expression and function in many cancer types, a crucial contributor to their synergy with ICIs in patients. Furthermore, epidermal growth factor receptor (EGFR) inhibitors and BRAF/mitogen-activated protein kinase kinase inhibitors are effective at upregulating HLA class I expression in EGFR-and BRAF-variant tumors, respectively; these changes may contribute to the clinical responses induced by these inhibitors in combination with ICIs.CONCLUSIONS AND RELEVANCE This narrative review summarizes evidence indicating that chemotherapy and targeted therapies are effective at enhancing HLA class I APM component expression and function in cancer cells. The resulting increased immunogenicity and recognition and elimination of cancer cells by cognate CTLs contributes to the antitumor activity of these therapies as well as to their synergy with ICIs.
Mitochondrial dynamics can regulate Major Histocompatibility Complex (MHC)-I antigen expression by cancer cells and their immunogenicity in mice and in patients with malignancies. A crucial role in the mitochondrial fragmentation connection with immunogenicity is played by the IRE1α-XBP-1s axis. XBP-1s is a transcription factor for aminopeptidase TPP2, which inhibits MHC-I complex cell surface expression likely by degrading tumor antigen peptides. Mitochondrial fission inhibition with Mdivi-1 upregulates MHC-I expression on cancer cells and enhances the efficacy of adoptive T cell therapy in patient-derived tumor models. Therefore mitochondrial fission inhibition might provide an approach to enhance the efficacy of T cell-based immunotherapy.
Studies assessing the efficacy of intralesional verapamil injection in the treatment of Peyronie's disease have yielded mixed results. The purpose of this meta‐analysis is to systematise the existing literature on the efficacy of intralesional verapamil injection when used in the treatment of Peyronie's disease. The treatment outcomes of seven different study groups identified by computerised literature search were compared with natural history outcomes and data from control groups of three studies involving placebo saline injection. An exploratory meta‐analysis was performed on the data due to differing patient populations, treatment protocols, and inconsistent selection and reporting of outcomes. Intralesional verapamil injection significantly improved sexual function (p < .0005) and penile curvature (p < .005) in individuals with Peyronie's disease. Decreases in pain may be significant after therapy but are questionable. The effect of verapamil on plaque size remains less impressive (p > .05). Intralesional verapamil injection has promise to positively impact a number of clinical outcomes of Peyronie's disease; however, a large, multicentre, randomised, controlled study with reliable protocols is needed to confirm the efficacy of treatment.
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