Neoadjuvant enoblituzumab in localized prostate cancer: a single-arm, phase 2 trial

UQCRB and LBH are correlated with Gleason score progression in prostate cancer: Spatial transcriptomics and experimental validation

Prostate cancer (PCa) is a multifocal disease characterized by genomic and phenotypic heterogeneity within a single gland. In this study, Visium spatial transcriptomics (ST) analysis was applied to PCa tissues with different histological structures to infer the molecular events involved in Gleason score (GS) progression. The spots in tissue sections were classified into various groups using Principal Component Analysis (PCA) and Louvain clustering analysis based on transcriptome data. Anotation of the spots according to GS revealed notable similarities between transcriptomic profiles and histologically identifiable structures. The accuracy of macroscopic GS determination was bioinformatically verified through malignancy-related feature analysis, specifically inferred copy number variation (inferCNV), as well as developmental trajectory analyses, such as diffusion pseudotime (DPT) and partition-based graph abstraction (PAGA). Genes related to GS progression were identified from the differentially expressed genes (DEGs) through pairwise comparisons of groups along a GS gradient. The proteins encoded by the representative oncogenes UQCRB and LBH were found to be highly expressed in advanced-stage PCa tissues. Knockdown of their mRNAs significantly suppressed PCa cell proliferation and invasion. These findings were validated using The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) dataset, as well as through histological and cytological experiments. The results presented here establish a foundation for ST-based evaluation of GS progression and provide valuable insights into the GS progression-related genes UQCRB and LBH.

Neoadjuvant lutetium PSMA, the TIME and immune response in high-risk localized prostate cancer

High-risk localized prostate cancer remains a lethal disease with high rates of recurrence, metastases and death, despite attempts at curative local treatment including surgery. Disease recurrence is thought to be a result of failure of local control and occult micrometastases. Neoadjuvant strategies before surgery have been effective in many cancers, but, to date, none has worked in this setting for prostate cancer. Prostate-specific membrane antigen (PSMA)-based theranostics is an exciting and rapidly evolving field in prostate cancer. The novel intravenous radionuclide therapy, [177Lu]Lu-PSMA-617 (lutetium PSMA) has been shown to be effective in treating men with metastatic castration-resistant prostate cancer, targeting cells expressing PSMA throughout the body. When given in a neoadjuvant setting, lutetium PSMA might also improve long-term oncological outcomes in men with high-risk localized disease. A component of radiotherapy is potentially an immunogenic form of cancer cell death. Lutetium PSMA could cause cancer cell death, resulting in release of tumour antigens and induction of a tumour-specific systemic immune response. This targeted radioligand treatment has the potential to treat local and systemic tumour sites by directly targeting cells that express PSMA, but might also act indirectly via this systemic immune response. In selected patients, lutetium PSMA could potentially be combined with systemic immunotherapies to augment the antitumour T cell response, and this might produce long-lasting immunity in prostate cancer.

Current uses and resistance mechanisms of enzalutamide in prostate cancer treatment

INTRODUCTION

Prostate cancer continues to be a major cause of morbidity and mortality for men worldwide. Enzalutamide, a second-generation non-steroidal antiandrogen that blocks androgen receptor (AR) transcriptional activity, is a treatment for biochemically recurrent, metastatic, castration-sensitive, and castration-resistant tumors. Unfortunately, most patients ultimately develop resistance to enzalutamide, making long-term treatment with this agent challenging.

AREAS COVERED

We performed a literature search of PubMed without date restrictions to investigate the literature surrounding enzalutamide and discuss the current uses of enzalutamide, proposed mechanisms driving resistance, and summarize current efforts to mitigate this resistance.

EXPERT OPINION

Enzalutamide is an effective prostate cancer therapy that is currently used in biochemically recurrent and metastatic disease and for both castration-sensitive and castration-resistant tumors. Unfortunately, resistance to enzalutamide occurs in each of these scenarios. In the clinical setting, enzalutamide-resistant tumors are either AR-driven or AR-indifferent. AR-dependent resistance mechanisms include genomic or epigenomic events that result in enhanced AR signaling. Tumors that do not require AR signaling instead may depend on alternative oncogenic pathways. There are numerous strategies to mitigate enzalutamide resistance, including concurrent use of PARP inhibitors or immune therapies. Additional work is required to uncover novel approaches to treat patients in the enzalutamide-resistant setting.

Novel bispecific antibody-drug conjugate targeting PD-L1 and B7-H3 enhances antitumor efficacy and promotes immune-mediated antitumor responses

BACKGROUND

Antibody-drug conjugates (ADCs) offer a promising approach, combining monoclonal antibodies with chemotherapeutic drugs to target cancer cells effectively while minimizing toxicity.

METHODS

This study examined the therapeutic efficacy and potential mechanisms of a bispecific ADC (BsADC) in laryngeal squamous cell carcinoma. This BsADC selectively targets the immune checkpoints programmed cell death ligand-1 (PD-L1) and B7-H3, and the precise delivery of the small-molecule toxin monomethyl auristatin E.

RESULTS

Our findings demonstrated that the BsADC outperformed its bispecific antibody and PD-L1 or B7-H3 ADC counterparts, particularly in terms of in vitro/in vivo tumor cytotoxicity, demonstrating remarkable immune cytotoxicity. Additionally, we observed potent activation of tumor-specific immunity and significant induction of markers of immunogenic cell death (ICD) and potential endoplasmic reticulum stress.

CONCLUSION

In conclusion, this novel BsADC, through immune checkpoint inhibition and promotion of ICD, amplified durable tumor immune cytotoxicity, providing novel insights and potential avenues for future cancer treatments and overcoming resistance.

Machine learning based androgen receptor regulatory gene-related random forest survival model for precise treatment decision in prostate cancer

Background

It has been demonstrated that aberrant androgen receptor (AR) signaling contributes to the pathogenesis of prostate cancer (PCa). To date, the most efficacious strategy for the treatment of PCa remains to target the AR signaling axis. However, numerous PCa patients still face the issue of overtreatment or undertreatment. The establishment of a precise risk prediction model is urgently needed to distinguish patients with high-risk and select appropriate treatment modalities.

Methods

In this study, a consensus AR regulatory gene-related signature (ARS) was developed by integrating a total of 101 algorithm combinations of 10 machine learning algorithms. We evaluated the value of ARS in predicting patient prognosis and the therapeutic effects of the various treatments. Additionally, we conducted a screening of therapeutic targets and agents for high-risk patients, followed by the verification in vitro and in vivo.

Results

ARS was an independent risk factor for biochemical recurrence and distant metastasis in PCa patients. The enhanced and consistent prognostic predictive capability of ARS across various platforms was confirmed when compared with 44 previously published signatures. More importantly, PCa patients in the ARShigh group benefit more from PARP inhibitors and immunotherapy, while chemotherapy, radiotherapy, and AR-targeted therapy are more effective for ARSlow patients. The results of in silico screening suggest that AURKB could potentially serve as a promising therapeutic target for ARShigh patients.

Conclusions

Collectively, this prediction model based on AR regulatory genes holds great clinical translational potential to solve the dilemma of treatment choice and identify potential novel therapeutic targets in PCa.

Spatial landscapes of cancers: insights and opportunities

Solid tumours comprise many different cell types organized in spatially structured arrangements, with substantial intratumour and intertumour heterogeneity. Advances in spatial profiling technologies over the past decade hold promise to capture the complexity of these cellular architectures to build a holistic view of the intricate molecular mechanisms that shape the tumour ecosystem. Some of these mechanisms act at the cellular scale and are controlled by cell-autonomous programmes or communication between nearby cells, whereas other mechanisms result from coordinated efforts between large networks of cells and extracellular molecules organized into tissues and organs. In this Review we provide insights into the application of single-cell and spatial profiling tools, with a focus on spatially resolved transcriptomic tools developed to understand the cellular architecture of the tumour microenvironment and identify opportunities to use them to improve clinical management of cancers.

Intraoperative Resection Guidance and Rapid Pathological Diagnosis of Osteosarcoma using B7H3 Targeted Probe under NIR-II Fluorescence Imaging

Complete removal of all tumor tissue with a wide surgical margin is essential for the treatment of osteosarcoma (OS). However, it's difficult, sometimes impossible, to achieve due to the invisible small satellite lesions and blurry tumor boundaries. Besides, intraoperative frozen-section analysis of resection margins of OS is often restricted by the hard tissues around OS, which makes it impossible to know whether a negative margin is achieved. Any unresected small tumor residuals will lead to local recurrence and worse prognosis. Herein, based on the high expression of B7H3 in OS, a targeted probe B7H3-IRDye800CW is synthesized by conjugating anti-B7H3 antibody and IRDye800CW. B7H3-IRDye800CW can accurately label OS areas after intravenous administration, thereby helping surgeons identify and resect residual OS lesions (<2 mm) and lung metastatic lesions. The tumor-background ratio reaches 4.42 ± 1.77 at day 3. After incubating fresh human OS specimen with B7H3-IRDye800CW, it can specifically label the OS area and even the microinvasion area (confirmed by hematoxylin-eosin [HE] staining). The probe labeled area is consistent with the tumor area shown by magnetic resonance imaging and complete HE staining of the specimen. In summary, B7H3-IRDye800CW has translational potential in intraoperative resection guidance and rapid pathological diagnosis of OS.

Oxygen-bridged W-Pd atomic pairs enable H2O2 activation for sensitive immunoassays

Regulating the performance of peroxidase (POD)-like nanozymes is a prerequisite for achieving highly sensitive and accurate immunoassays. Inspired by natural enzyme catalysis, we design a highly active and selective nanozyme by loading atomically dispersed tungsten (W) sites on Pd metallene (W-O-Pdene) to construct an artificial three-dimensional (3D) catalytic center. The 3D asymmetric W-O-Pd atomic pairs can effectively stretch the O-O bonds in H2O2 and further promote the desorption of H2O to enhance POD-like activity. Moreover, the W-O-Pd sites with unique spatial structures demonstrate satisfactory specificity for H2O2 activation, effectively preventing the interference of dissolved oxygen. Accordingly, the highly active and specific W-O-Pdene nanozymes are utilized for sensitive and accurate prostate-specific antigen (PSA) immunoassay with a low detection limit of 1.92 pg mL-1, superior to commercial enzyme-linked immunosorbent assay.

Tumor ABCC4-mediated release of PGE2 induces CD8+ T cell dysfunction and impairs PD-1 blockade in prostate cancer

Prostate cancer presents as an immunologically "cold" malignancy, characterized by a lack of response to immunotherapy in the majority of patients. The dysfunction of prostate tumor metabolism is recognized as a critical factor in immune evasion, resulting in reduced effectiveness of immunotherapeutic interventions. Despite this awareness, the precise molecular mechanisms underpinning metabolic dysregulation in prostate cancer and its intricate relationship with immune evasion remain incompletely elucidated. In this study, we introduce the multi-drug resistance protein ABCC4/MRP4 as a key player prominently expressed in prostate cancer, exerting a pivotal role in suppressing the activity of intratumoral CD8+ T cells. Depletion of ABCC4 in prostate cancer cells halts the release of prostaglandin E2 (PGE2), a molecule that diminishes the population of CD8+ T cells and curtails their cytotoxic capabilities. Conversely, constraining the activation of PGE2 signaling in CD8+ T cells effectively improved the efficacy of prostate cancer treatment with PD-1 blockade. During this process, downregulation of the JAK1-STAT3 pathway and depolarization of mitochondria emerge as crucial factors contributing to T cell anergy. Collectively, our research identifies the ABCC4-PGE2 axis as a promising target for reversing dysfunction within tumor-infiltrating lymphocytes (TILs) and augmenting the suboptimal responsiveness to immunotherapy in prostate cancer.

ITGB6 modulates resistance to anti-CD276 therapy in head and neck cancer by promoting PF4+ macrophage infiltration

Enoblituzumab, an immunotherapeutic agent targeting CD276, shows both safety and efficacy in activating T cells and oligodendrocyte-like cells against various cancers. Preclinical studies and mouse models suggest that therapies targeting CD276 may outperform PD1/PD-L1 blockade. However, data from mouse models indicate a significant non-responsive population to anti-CD276 treatment, with the mechanisms of resistance still unclear. In this study, we evaluate the activity of anti-CD276 antibodies in a chemically-induced murine model of head and neck squamous cell carcinoma. Using models of induced and orthotopic carcinogenesis, we identify ITGB6 as a key gene mediating differential responses to anti-CD276 treatment. Through single-cell RNA sequencing and gene-knockout mouse models, we find that ITGB6 regulates the expression of the tumor-associated chemokine CX3CL1, which recruits and activates PF4+ macrophages that express high levels of CX3CR1. Inhibition of the CX3CL1-CX3CR1 axis suppresses the infiltration and secretion of CXCL16 by PF4+ macrophages, thereby reinvigorating cytotoxic CXCR6+ CD8+ T cells and enhancing sensitivity to anti-CD276 treatment. Further investigations demonstrate that inhibiting ITGB6 restores sensitivity to PD1 antibodies in mice resistant to anti-PD1 treatment. In summary, our research reveals a resistance mechanism associated with immune checkpoint inhibitor therapy and identifies potential targets to overcome resistance in cancer treatment.

Chimeric Antigen Receptor T Cell with an Inducible Caspase-9 Suicide Gene Eradicates Uveal Melanoma Liver Metastases via B7-H3 Targeting

PURPOSE

Uveal melanoma (UM) is the most common intraocular malignant tumor. Despite successful treatment of the primary tumor, about 50% of patients will recur with systemic diseases for which there are no effective treatment strategies. Here we investigated the preclinical efficacy of a chimeric antigen receptor (CAR) T-cell-based immunotherapy targeting B7-H3.

EXPERIMENTAL DESIGN

B7-H3 expression on primary and metastatic human UM samples and cell lines was assessed by RNA sequencing, flow cytometry, and immunohistochemistry. Antitumor activity of CAR T cells targeting B7-H3 was tested in vitro with UM cell lines, patient-derived organotypic tumor spheroids from patients with metastatic UM, and in immunodeficient and humanized murine models.

RESULTS

B7-H3 is expressed at high levels in >95% UM tumor cells in vitro and in vivo. We generated a B7-H3 CAR with an inducible caspase-9 (iCas9) suicide gene controlled by the chemical inducer of dimerization AP1903, which effectively kills UM cells in vitro and eradicates UM liver metastases in murine models. Delivery of iCas9.B7-H3 CAR T cells in experimental models of UM liver metastases demonstrates a durable antitumor response, even upon tumor rechallenge or in the presence of a significant metastatic disease burden. We demonstrate effective iCas9.B7-H3 CAR T-cell elimination in vitro and in vivo in response to AP1903. Our studies demonstrate more effective tumor suppression with iCas9.B7-H3 CAR T cells as compared to a B7-H3-targeted humanized monoclonal antibody.

CONCLUSIONS

These studies support a phase I clinical trial with iCas9.B7-H3 CAR T cells to treat patients with metastatic UM.

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.

Facts and Hopes on Cancer Immunotherapy for Small Cell Lung Cancer

Platinum-based chemotherapy plus PD1 axis blockade is the standard of care in the first-line treatment of extensive-stage small cell lung cancer (SCLC). Despite the robust and consistent increase in long-term survival with PD1 axis inhibition, the magnitude of the benefit from immunotherapy seems lower than that for other solid tumors. Several immune evasive mechanisms have been shown to be prominently altered in human SCLC, including T-cell exclusion, downregulation of components of the MHC class I antigen processing and presentation machinery, or upregulation of macrophage inhibitory checkpoints, among others. New immunotherapies aiming to target some of these dominant immune suppressive features are being intensively evaluated preclinically and clinically in SCLC. They include strategies to enhance the efficacy and/or reverse features that promote intrinsic resistance to PD1 axis inhibition (e.g., restoring MHC class I deficiency and targeting DNA damage response) and novel immunomodulatory agents beyond T-cell checkpoint blockers (e.g., T cell-redirecting strategies, antibody-drug conjugates, or macrophage checkpoint blockers). Among them, delta-like ligand 3-targeted bispecific T-cell engagers have shown the most compelling preliminary evidence of clinical efficacy and hold promise as therapies that might contribute to further improve patient outcomes in this disease. In this study, we first provide a brief overview of key tumor microenvironment features of human SCLC. Then, we update the current clinical evidence with immune checkpoint blockade and review other emerging immunotherapy strategies that are gaining increasing attention in SCLC. We finally summarize our future perspective on immunotherapy and precision oncology for this disease.

Small Extracellular Vesicle piR-hsa-30937 Derived from Pancreatic Neuroendocrine Neoplasms Upregulates CD276 in Macrophages to Promote Immune Evasion

The role of PIWI-interacting RNAs (piRNA) in small extracellular vesicles (sEV) derived from pancreatic neuroendocrine neoplasms (PNEN) in the tumor microenvironment (TME) remains unexplored. We used multiplex IHC to analyze the expression of CD68, CD276 (B7H3), and CD3 on PNEN. CD276+ tumor-associated macrophages (TAM) were more abundant in tumor tissues than nontumor tissues and negatively correlated with T-cell infiltration. Serum sEV piRNA sequencing was performed to identify piRNAs enriched in patients with PNEN. We then investigated the function and mechanism of sEV piR-hsa-30937 in the cross-talk between tumor cells and macrophages in the PNEN TME. PNEN-derived sEV piR-hsa-30937 targeted PTEN to activate the AKT pathway and drive CD276 expression. CD276+ macrophages inhibited T-cell proliferation and IFNγ production. piR-hsa-30937 knockdown and anti-CD276 treatment suppressed progression and metastasis in a preclinical model of PNEN by enhancing T-cell immunity. Thus, our data show that PNEN-derived sEV piR-hsa-30937 promotes CD276 expression in macrophages through the PTEN/AKT pathway and that CD276+ TAMs suppress T-cell antitumor immunity. sEV piR-hsa-30937 and CD276 are potential therapeutic targets for immunotherapy of PNEN.

Enhancing surgical outcomes: accurate identification and removal of prostate cancer with B7-H3-targeted NIR-II molecular imaging

PURPOSE

One of the main reasons for prostate cancer (PCa) recurrence is the difficulty in identifying and removing cancerous lesions during surgery. Accurately localizing and excising cancerous tissue remains a significant challenge. The second near-infrared window (NIR-II, 1000-1700 nm) fluorescence offers enhanced resolution, a high signal-to-noise ratio, and the potential for deeper tissue penetration. However, this technology is not currently employed for intraoperative imaging of PCa. This study aims to construct a new NIR-II probe targeting B7-H3 (AbB7-H3-800CW) for accurate intraoperative identification and resection of PCa.

METHODS

Based on the differential expression of B7-H3 in PCa, we designed a novel imaging probe to accurately identify and guide the resection of preclinical PCa models and ex vivo human PCa tissues using NIR-II fluorescence imaging technology.

RESULTS

Analyzing tissue samples from 60 clinical cases of PCa, along with benign prostatic hyperplasia and normal prostate tissue from 22 cases, we observed a significant difference in B7-H3 protein expression levels (P < 0.001). Subcutaneous and orthotopic mouse models of PCa were imaged using NIR-II fluorescence after AbB7-H3-800CW injection, showing promising results with successful tumor targeting and high-contrast images achieved within 24-48 h post-injection. The imaging also enabled the detection of occult PCa lesions approximately 1 mm in diameter. In addition, imaging analysis of human PCa and adjacent tissues using AbB7-H3-800CW incubation revealed that cancer tissues exhibited a significantly higher fluorescence intensity than adjacent tissues (P < 0.05), which was conducive to the evaluation of tumor resection margin in vitro.

CONCLUSION

The findings revealed that B7-H3 was a compelling imaging target for PCa. The AbB7-H3-800CW molecular imaging probe is capable of accurately identifying PCa lesions and guiding their removal. This approach can potentially reduce the rate of surgical margins under NIR-II fluorescence guidance.

B7-H3: a robust target for immunotherapy in prostate cancer

B7-H3, an immune checkpoint glycoprotein, facilitates immune evasion and the promotion of tumors and is highly expressed on the surface of prostate cancer (PCa) cells, which makes it a feasible and robust candidate for immunotherapies against advanced prostate cancer. Here, we summarize and discuss recent findings on the suitability of targeting B7-H3 in PCa treatment.

The combination of immune checkpoint inhibitors and antibody-drug conjugates in the treatment of urogenital tumors: a review insights from phase 2 and 3 studies

With the high incidence of urogenital tumors worldwide, urinary system tumors are among the top 10 most common tumors in men, with prostate cancer ranking first and bladder cancer fourth. Patients with resistant urogenital tumors often have poor prognosis. In recent years, researchers have discovered numerous specific cancer antigens, which has led to the development of several new anti-cancer drugs. Using protein analysis techniques, researchers developed immune checkpoint inhibitors (ICIs) and antibody-conjugated drugs (ADCs) for the treatment of advanced urogenital tumors. However, tumor resistance often leads to the failure of monotherapy. Therefore, clinical trials of the combination of ICIs and ADCs have been carried out in numerous centers around the world. This article reviewed phase 2 and 3 clinical studies of ICIs, ADCs, and their combination in the treatment of urogenital tumors to highlight safe and effective methods for selecting individualized therapeutic strategies for patients. ICIs activate the immune system, whereas ADCs link monoclonal antibodies to toxins, which can achieve a synergistic effect when the two drugs are combined. This synergistic effect provides multiple advantages for the treatment of urogenital tumors.

The miR-29 family facilitates the activation of NK-cell immune responses by targeting the B7-H3 immune checkpoint in neuroblastoma

Neuroblastoma (NB) is a highly aggressive pediatric cancer that originates from immature nerve cells, presenting significant treatment challenges due to therapy resistance. Despite intensive treatment, approximately 50% of high-risk NB cases exhibit therapy resistance or experience relapse, resulting in poor outcomes often associated with tumor immune evasion. B7-H3 is an immune checkpoint protein known to inhibit immune responses. MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation. Our study aims to explore the impact of miRNAs on B7-H3 regulation, the anti-tumor immune response, and tumorigenicity in NB. Analysis of NB patients and patient-derived xenograft tumors revealed a correlation between higher B7-H3 expression and poorer patient survival. Notably, deceased patients exhibited a depletion of miR-29 family members (miR-29a, miR-29b, and miR-29c), which displayed an inverse association with B7-H3 expression in NB patients. Overexpression and knockdown experiments demonstrated that these miRNAs degrade B7-H3 mRNA, resulting in enhanced NK cell activation and cytotoxicity. In vivo, experiments provided further evidence that miR-29 family members reduce tumorigenicity, macrophage infiltration, and microvessel density, promote infiltration and activation of NK cells, and induce tumor cell apoptosis. These findings offer a rationale for developing more effective combination treatments that leverage miRNAs to target B7-H3 in NB patients.

Emerging Targets and Therapeutics in Immuno-Oncology: Insights from Landscape Analysis

In the ever-evolving landscape of cancer research, immuno-oncology stands as a beacon of hope, offering novel avenues for treatment. This study capitalizes on the vast repository of immuno-oncology-related scientific documents within the CAS Content Collection, totaling over 350,000, encompassing journals and patents. Through a pioneering approach melding natural language processing with the CAS indexing system, we unveil over 300 emerging concepts, depicted in a comprehensive "Trend Landscape Map". These concepts, spanning therapeutic targets, biomarkers, and types of cancers among others, are hierarchically organized into eight major categories. Delving deeper, our analysis furnishes detailed quantitative metrics showcasing growth trends over the past three years. Our findings not only provide valuable insights for guiding future research endeavors but also underscore the merit of tapping the vast and unparalleled breadth of existing scientific information to derive profound insights.

Cancer therapy with antibodies

The greatest challenge in cancer therapy is to eradicate cancer cells with minimal damage to normal cells. Targeted therapy has been developed to meet that challenge, showing a substantially increased therapeutic index compared with conventional cancer therapies. Antibodies are important members of the family of targeted therapeutic agents because of their extraordinarily high specificity to the target antigens. Therapeutic antibodies use a range of mechanisms that directly or indirectly kill the cancer cells. Early antibodies were developed to directly antagonize targets on cancer cells. This was followed by advancements in linker technologies that allowed the production of antibody-drug conjugates (ADCs) that guide cytotoxic payloads to the cancer cells. Improvement in our understanding of the biology of T cells led to the production of immune checkpoint-inhibiting antibodies that indirectly kill the cancer cells through activation of the T cells. Even more recently, bispecific antibodies were synthetically designed to redirect the T cells of a patient to kill the cancer cells. In this Review, we summarize the different approaches used by therapeutic antibodies to target cancer cells. We discuss their mechanisms of action, the structural basis for target specificity, clinical applications and the ongoing research to improve efficacy and reduce toxicity.

Pan-Cancer Interrogation of B7-H3 (CD276) as an Actionable Therapeutic Target Across Human Malignancies

B7-H3 (CD276) is a transmembrane glycoprotein of the B7 immune checkpoint superfamily that has emerged as a promising therapeutic target. To better understand the applicability of B7-H3-directed therapies, we analyzed 156,791 samples comprising 50 cancer types to interrogate the clinical, genomic, transcriptomic, and immunologic correlates of B7-H3 mRNA expression. DNA (592-gene/whole-exome) and RNA (whole-transcriptome) sequencing was performed from samples submitted to Caris Life Sciences. B7-H3 high versus low expression was based on top and bottom quartiles for each cancer type. Patients' overall survival was determined from insurance claims data. Pathway analysis was performed using gene set enrichment analyses. Immune cell fractions were inferred using quanTIseq. B7-H3 is expressed across several human malignancies including prostate, pancreatic, ovarian, and lung cancers. High B7-H3 expression is associated with differences in overall survival, possibly indicating a prognostic role of B7-H3 for some cancers. When examining molecular features across all cancer types, we did not identify recurrent associations between B7-H3 expression and genetic alterations in TP53, RB1, and KRAS. However, we find consistent enrichment of epithelial-to-mesenchymal transition, Wnt, TGFβ, and Notch signaling pathways. In addition, tumors with high B7-H3 expression are associated with greater proportions of M1 macrophages, but lower fractions of CD8+ T cells. We have begun to define the genomic, transcriptomic, clinical, and immunologic features associated with B7-H3 expression in 50 cancer types. We report novel clinical and molecular features of B7-H3-high tumors which may inform how current B7-H3 therapeutics should be deployed and prioritized.

SIGNIFICANCE

B7-H3-targeting therapeutics have shown promising results in initial clinical trials. In this pan-cancer analysis of B7-H3 mRNA expression, we found that B7-H3 exhibits robust expression in many common cancer types. These results may inform further development of B7-H3-targeting therapeutics and may guide clinical decisions for patients with limited treatment options.

Integrating single-cell RNA-sequencing and bulk RNA-sequencing data to explore the role of mitophagy-related genes in prostate cancer

Prostate cancer (PCa) is the most common malignancy of the male urinary system. Mitophagy, as a type of autophagy, can remove damaged mitochondria in cells. Mitophagy-related genes (MRGs) have been shown to play critical roles in the development of PCa. To this end, based on the comprehensive analysis of RNA-seq and scRNA-seq data of PCa samples and their controls, this paper identified PCa subtypes and constructed a prognostic model. In this paper, we downloaded scRNA-seq and RNA-seq data from Gene Expression Omnibus (GEO) and TCGA database. Based on the R package "Seurat" to process the scRNA-seq data, a total of five cell types were identified. Each cell population was scored based on the R package "AUCell" and using the intersection genes between MRGs and each cell population. The B cell population was then identified as a high-scoring cell population. Differentially expressed genes in RNA-seq data were identified based on the R package "limma" and intersected with previously intersected genes. Then, based on univariate Cox regression analysis and Lasso-Cox regression analysis, the prognostic genes were screened, and the risk model was constructed (composed of ADH5, CAT, BCAT2, DCXR, OGT, and FUS). The model is validated on internal and external test sets. Independent prognostic analysis identified age, N stage, and risk score as independent prognostic factors. This paper's risk models and prognostic genes can provide a reference for developing novel therapeutic targets for PCa.

Fully human anti-B7-H3 recombinant antibodies inhibited tumor growth by increasing T cell infiltration

Mortality due to malignant tumors is one of the major factors affecting the life expectancy of the global population. Therapeutic antibodies are a cutting-edge treatment method for restricting tumor growth. B7-H3 is highly expressed in tumor tissues, but rarely in normal tissues. B7-H3 is closely associated with poor prognosis in patients with tumors. B7-H3 is an important target for antitumor therapy. In this study, the fully human anti-B7H3 single-chain antibodies (scFvs) were isolated and screened from the fully human phage immune library with B7H3 as the target. The antibodies screened from a fully human phage library had low immunogenicity and high affinity, which was more beneficial for clinical application. Leveraging B7-H3 scFvs as a foundation, we constructed two distinct recombinant antibody formats, scFv-Fc and IgG1, characterized by elevated affinity and a prolonged half-life. The results demonstrated that the recombinant antibodies had high specificity and affinity for the B7-H3 antigen and inhibited tumor cell growth by enhancing the ADCC. After treatment with anti-B7H3 recombinant antibody, the number of infiltrating T cells in the tumor increased and the secretion of IFN- γ by infiltrating T cells increased in vivo. Additionally, the use of pleural fluid samples obtained from tumor-afflicted patients revealed the ability of anti-B7-H3 recombinant antibodies to reverse CD8+ T cell exhaustion. In summary, we screened the fully human anti-B7H3 recombinant antibodies with specificity and high affinity that increase immune cell infiltration and IFN-γ secretion, thereby inhibiting tumor cell growth to a certain extent. This finding provides a theoretical basis for the development of therapeutic tumor antibodies and could help promote further development of antibody-based drugs.

Development of a Human B7-H3-Specific Antibody with Activity against Colorectal Cancer Cells through a Synthetic Nanobody Library

Nanobodies have emerged as promising tools in biomedicine due to their single-chain structure and inherent stability. They generally have convex paratopes, which potentially prefer different epitope sites in an antigen compared to traditional antibodies. In this study, a synthetic phage display nanobody library was constructed and used to identify nanobodies targeting a tumor-associated antigen, the human B7-H3 protein. Combining next-generation sequencing and single-clone validation, two nanobodies were identified to specifically bind B7-H3 with medium nanomolar affinities. Further characterization revealed that these two clones targeted a different epitope compared to known B7-H3-specific antibodies, which have been explored in clinical trials. Furthermore, one of the clones, dubbed as A6, exhibited potent antibody-dependent cell-mediated cytotoxicity (ADCC) against a colorectal cancer cell line with an EC50 of 0.67 nM, upon conversion to an Fc-enhanced IgG format. These findings underscore a cost-effective strategy that bypasses the lengthy immunization process, offering potential rapid access to nanobodies targeting unexplored antigenic sites.

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.

B7-H3 at the crossroads between tumor plasticity and colorectal cancer progression: a potential target for therapeutic intervention

B7-H3 (B7 homology 3 protein) is an important transmembrane immunoregulatory protein expressed in immune cells, antigen-presenting cells, and tumor cells. Studies reveal a multifaceted role of B7-H3 in tumor progression by modulating various cancer hallmarks involving angiogenesis, immune evasion, and tumor microenvironment, and it is also a promising candidate for cancer immunotherapy. In colorectal cancer (CRC), B7-H3 has been associated with various aspects of disease progression, such as evasion of tumor immune surveillance, tumor-node metastasis, and poor prognosis. Strategies to block or interfere with B7-H3 in its immunological and non-immunological functions are under investigation. In this study, we explore the role of B7-H3 in tumor plasticity, emphasizing tumor glucose metabolism, angiogenesis, epithelial-mesenchymal transition, cancer stem cells, apoptosis, and changing immune signatures in the tumor immune landscape. We discuss how B7-H3-induced tumor plasticity contributes to immune evasion, metastasis, and therapy resistance. Furthermore, we delve into the most recent advancements in targeting B7-H3-based tumor immunotherapy as a potential approach to CRC treatment.

Localized high-risk prostate cancer harbors an androgen receptor low subpopulation susceptible to HER2 inhibition

Patients diagnosed with localized high-risk prostate cancer have higher rates of recurrence, and the introduction of neoadjuvant intensive hormonal therapies seeks to treat occult micrometastatic disease by their addition to definitive treatment. Sufficient profiling of baseline disease has remained a challenge in enabling the in-depth assessment of phenotypes associated with exceptional vs. poor pathologic responses after treatment. In this study, we report comprehensive and integrative gene expression profiling of 37 locally advanced prostate tumors prior to six months of androgen deprivation therapy (ADT) plus the androgen receptor (AR) inhibitor enzalutamide prior to radical prostatectomy. A robust transcriptional program associated with HER2 activity was positively associated with poor outcome and opposed AR activity, even after adjusting for common genomic alterations in prostate cancer including PTEN loss and expression of the TMPRSS2:ERG fusion. Patients experiencing exceptional pathologic responses demonstrated lower levels of HER2 and phospho-HER2 by immunohistochemistry of biopsy tissues. The inverse correlation of AR and HER2 activity was found to be a universal feature of all aggressive prostate tumors, validated by transcriptional profiling an external cohort of 121 patients and immunostaining of tumors from 84 additional patients. Importantly, the AR activity-low, HER2 activity-high cells that resist ADT are a pre-existing subset of cells that can be targeted by HER2 inhibition alone or in combination with enzalutamide. In summary, we show that prostate tumors adopt an AR activity-low prior to antiandrogen exposure that can be exploited by treatment with HER2 inhibitors.

Disruption of LPA-LPAR1 pathway results in lung tumor growth inhibition by downregulating B7-H3 expression in fibroblasts

BACKGROUND

Lysophosphatidic acids (LPAs) belong to a class of bioactive lysophospholipids with multiple functions including immunomodulatory roles in tumor microenvironment (TME). LPA exerts its biological effects via its receptors that are highly expressed in fibroblasts among other cell types. As cancer-associated fibroblasts (CAFs) are a key component of the TME, it is important to understand LPA signaling and regulation of receptors in fibroblasts or CAFs and associated regulatory roles on immunomodulation-related molecules.

METHODS

Cluster analysis, immunoblotting, real-time quantitative-PCR, CRISPR-Cas9 gene editing system, immunohistochemical staining, coculture model, and in vivo xenograft model were used to investigate the effects of LPA-LPAR1 on B7-H3 in tumor promotion of CAFs.

RESULTS

In this study, we found that LPAR1 and CD276 (B7-H3) were generally highly expressed in fibroblasts with good expression correlation. LPA induced B7-H3 up-expression through LPAR1, and stimulated fibroblasts proliferation that could be inhibited by silencing LPAR1 or B7-H3 as well as small molecule LPAR1 antagonist (Ki16425). Using engineered fibroblasts and non-small cell lung carcinoma (NSCLC) cell lines, subsequent investigations demonstrated that CAFs promoted the proliferation of NSCLC in vitro and in vivo, and such effect could be inhibited by knocking out LPAR1 or B7-H3.

CONCLUSION

The present study provided new insights for roles of LPA in CAFs, which could lead to the development of innovative therapies targeting CAFs in the TME. It is also reasonable to postulate a combinatory approach to treat malignant fibrous tumors (such as NSCLC) with LPAR1 antagonists and B7-H3 targeting therapies.

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/CD276 and small-cell lung cancer: What's new?

Immunotherapy revolutionized the treatment landscape of several cancers, including small-cell lung cancer (SCLC), with a huge number of practice-changing trials, and becoming a new frontier for their management. The addition of an anti-PD-L1, atezolizumab or durvalumab, to platinum/etoposide regimen became the standard of care for first-line therapy of extensive-stage (ES)-SCLC with the 12 months median survival exceeded for the first time. Nevertheless, most patients show primary or acquired resistance to anti-PD-L1 therefore new promising therapeutic immune-targets are under clinical investigation in several solid tumors. Among these, B7-H3, also known as CD276, is a member of the B7 family overexpressed in tumor tissues, including SCLC, while showing limited expression in normal tissues becoming an attractive and promising target for cancer immunotherapy. B7-H3 plays a dual role in the immune system during the T-cell activation, acting as a T-cell costimulatory/coinhibitory immunoregulatory protein, and promoting pro-tumorigenic functions such as tumor migration, invasion, metastases, resistance, and metabolism. Immunohistochemistry, flow cytometry, and immunofluorescence were the most used methods to assess B7-H3 expression levels and validate a possible relationship between B7-H3 staining patterns and clinicopathological features in lung cancer patients. To date, there are no clinically available therapeutics/drugs targeting B7-H3 in any solid tumors. The most promising preliminary clinical results have been reported by DS7300a and HS-20093, both are antibody-drug conjugates, that are under investigation in ongoing trials for the treatment of pretreated SCLC. This review will provide an overview of B7-H3 and corresponding inhibitors and the clinical development in the management of SCLC.

Pembrolizumab for metastatic castration-resistant prostate cancer: trials and tribulations

INTRODUCTION

Immunotherapies have revolutionized the management of various malignancies but have only recently been evaluated systematically in prostate cancer. Pembrolizumab, a programmed-death 1 (PD-1) blocking antibody, has been utilized in a small subset of prostate cancer patients with mismatch repair deficiency/microsatellite instability, but has now been assessed in broader populations of metastatic prostate cancer patients.

AREAS COVERED

The results of four pembrolizumab-based phase III clinical trials for metastatic castration-resistant prostate cancer (mCRPC) and metastatic hormone-sensitive prostate cancer (mHSPC) patients, including KEYNOTE-641, KEYNOTE-921, KEYNOTE-991, and KEYLYNK-010 are summarized. Programmed death-ligand 1 (PD-L1) expression, the efficacy of pembrolizumab in prostate cancer patients with certain molecular defects, and emerging pembrolizumab-based therapeutic combinations are also reviewed.

EXPERT OPINION

Pembrolizumab has not benefitted unselected metastatic prostate cancer patients when combined with chemotherapy, next-generation hormonal agents (NHA), or poly(ADP-ribose) polymerase inhibitors (PARPi). PD-L1 positivity does not predict the response to pembrolizumab in this disease. A small number of responding patients can likely be explained by rare genetic and molecular defects, and more innovative combination strategies are needed to improve outcomes in prostate cancer patients who are not sensitive to pembrolizumab. Emphasis should be placed on developing additional or alternative immuno-oncology approaches beyond classical immune checkpoint inhibition.

Genitourinary cancer neoadjuvant therapies: current and future approaches

Neoadjuvant therapies can improve tolerability, reduce tumor volume to facilitate surgery, and assess subsequent treatment response. Therefore, there is much enthusiasm for expanding the benefits of cancer therapies to the neoadjuvant setting to reduce recurrence and improve survival in patients with localized or locally advanced genitourinary (GU) cancer. This approach is clinically pertinent because these treatments are administered primarily to treatment-naive patients and can elicit the greatest drug response. In addition, the results are not impacted by other anticancer treatments. While neoadjuvant therapies have been the standard treatment for bladder cancer in the past, they are presently restricted to clinical trials for renal and prostate cancer (PCa); however, changes are imminent. Precision neoadjuvant therapies will be ushered in by biomarker-stratified neoadjuvant trials with appropriate survival endpoints and comprehensive correlative and imaging studies. This review discusses neoadjuvant studies in GU malignancies and how they inform future study design considerations.

The potential role of the microbiota in prostate cancer pathogenesis and treatment

The human body hosts a complex and dynamic population of trillions of microorganisms - the microbiota - which influences the body in homeostasis and disease, including cancer. Several epidemiological studies have associated specific urinary and gut microbial species with increased risk of prostate cancer; however, causal mechanistic data remain elusive. Studies have associated bacterial generation of genotoxins with the occurrence of TMPRSS2-ERG gene fusions, a common, early oncogenic event during prostate carcinogenesis. A subsequent study demonstrated the role of the gut microbiota in prostate cancer endocrine resistance, which occurs, at least partially, through the generation of androgenic steroids fuelling oncogenic signalling via the androgen receptor. These studies present mechanistic evidence of how the host microbiota might be implicated in prostate carcinogenesis and tumour progression. Importantly, these findings also reveal potential avenues for the detection and treatment of prostate cancer through the profiling and modulation of the host microbiota. The latter could involve approaches such as the use of faecal microbiota transplantation, prebiotics, probiotics, postbiotics or antibiotics, which can be used independently or combined with existing treatments to reverse therapeutic resistance and improve clinical outcomes in patients with prostate cancer.

A novel microenvironment regulated system CAR-T (MRS.CAR-T) for immunotherapeutic treatment of esophageal squamous carcinoma

Chimeric antigen receptor T cell immunotherapy has achieved promising therapeutic effects in the treatment of hematological malignancies. However, there are still many obstacles, including on-target off-tumor antigen expression, that prevent successful application to solid tumors. We designed a tumor microenvironment (TME) regulated system chimeric antigen receptor T (MRS.CAR-T) which can only be auto-activated in the solid TME. B7-H3 was selected as the target antigen for esophageal carcinoma. An element comprising a human serum albumin (HSA) binding peptide and a matrix metalloproteases (MMPs) cleavage site was inserted between the 5' terminal signal peptide and single chain fragment variable (scFv) of the CAR skeleton. Upon administration, HSA bound the binding peptide in MRS.B7-H3.CAR-T effectively and promoted proliferation and differentiation into memory cells. MRS.B7-H3.CAR-T was not cytotoxic in normal tissues expressing B7-H3 as the antigen recognition site in the scFv was cloaked by HSA. The anti-tumor function of MRS.B7-H3.CAR-T was recovered once the cleavage site was cleaved by MMPs in the TME. The anti-tumor efficacy associated with MRS.B7-H3.CAR-T cells was improved compared to classic B7-H3.CAR-T cells in vitro and less IFN-γ was released, suggesting a treatment that may induce less extent of cytokine release syndrome-mediated toxicity. In vivo, MRS.B7-H3.CAR-T cells had strong anti-tumor activity and were safe. MRS.CAR-T represents a novel strategy to improve the efficacy and safety of CAR-T therapy in solid tumors.

Immune checkpoint B7-H3 is a therapeutic vulnerability in prostate cancer harboring PTEN and TP53 deficiencies

Checkpoint immunotherapy has yielded meaningful responses across many cancers but has shown modest efficacy in advanced prostate cancer. B7 homolog 3 protein (B7-H3/CD276) is an immune checkpoint molecule and has emerged as a promising therapeutic target. However, much remains to be understood regarding B7-H3's role in cancer progression, predictive biomarkers for B7-H3-targeted therapy, and combinatorial strategies. Our multi-omics analyses identified B7-H3 as one of the most abundant immune checkpoints in prostate tumors containing PTEN and TP53 genetic inactivation. Here, we sought in vivo genetic evidence for, and mechanistic understanding of, the role of B7-H3 in PTEN/TP53-deficient prostate cancer. We found that loss of PTEN and TP53 induced B7-H3 expression by activating transcriptional factor Sp1. Prostate-specific deletion of Cd276 resulted in delayed tumor progression and reversed the suppression of tumor-infiltrating T cells and NK cells in Pten/Trp53 genetically engineered mouse models. Furthermore, we tested the efficacy of the B7-H3 inhibitor in preclinical models of castration-resistant prostate cancer (CRPC). We demonstrated that enriched regulatory T cells and elevated programmed cell death ligand 1 (PD-L1) in myeloid cells hinder the therapeutic efficacy of B7-H3 inhibition in prostate tumors. Last, we showed that B7-H3 inhibition combined with blockade of PD-L1 or cytotoxic T lymphocyte-associated protein 4 (CTLA-4) achieved durable antitumor effects and had curative potential in a PTEN/TP53-deficient CRPC model. Given that B7-H3-targeted therapies have been evaluated in early clinical trials, our studies provide insights into the potential of biomarker-driven combinatorial immunotherapy targeting B7-H3 in prostate cancer, among other malignancies.

Metastatic Castration-Resistant Prostate Cancer, Immune Checkpoint Inhibitors, and Beyond

The therapeutic landscape of several genitourinary malignancies has been revolutionized by the development of immune checkpoint inhibitors (ICIs); however, the utility of immunotherapies in prostate cancer has been limited, partly due to the immunologically "cold" tumor terrain of prostate cancer. As of today, pembrolizumab is the only immune checkpoint inhibitor approved for the treatment of metastatic castration resistant prostate cancer (mCRPC) in a select group of patients with high microsatellite instability (MSI-H), deficient mismatch repair (dMMR), or high tumor mutational burden (TMB). Looking ahead, several combinatorial approaches with ICIs involving radioligands, radiotherapy, PARP inhibitors, interleukin inhibitors, and cancer vaccines are exploring a potential synergistic effect. Furthermore, B7-H3 is an alternative checkpoint that may hold promise in adding to the treatment landscape of mCRPC. This review aims to summarize previous monotherapy and combination therapy trials of ICIs as well as novel immunotherapy combination therapeutic strategies and treatment targets in mCRPC.