Background Metastatic castration-resistant prostate cancer (mCRPC) is an aggressive, treatment-refractory stage of disease with limited treatment options and poor prognosis. Chimeric antigen receptor (CAR)-T cell therapy has demonstrated success in hematological malignancies. However, responses in solid tumors remain variable, underscoring the need for improved real-time monitoring of tumor biology and therapeutic response.Methods In this exploratory, retrospective analysis within a CAR-T clinical trial (NCT03873805), we characterized the circulatory tumor landscape of mCRPC using a high-resolution, single-cell, enrichment-free liquid biopsy platform integrating phenotypic and genomic profiling of circulating tumor cells (CTCs) and other rare cells. Longitudinal peripheral blood (PB) and bone marrow aspirate (BMA) samples were collected from eight patients (four clinical responders, four non-responders) before lymphodepletion (LD), before infusion, and after therapy. Fluorescent whole-slide imaging was used to identify rare cell phenotypes, and single-cell whole-genome copy-number variation profiling was performed to assess clonal identity.Results LD mobilized CTCs from bone marrow into PB, altering compartmental cellularity regardless of response. Single-cell genomic analysis identified clonally altered CTC populations with response-aligned dynamics: responders demonstrated post-infusion clonal reduction, whereas non-responders exhibited persistence across time points and compartments. Clonal tumor populations frequently spanned epithelial and immune-like CTC phenotypes, indicating phenotypic heterogeneity within shared lineages.Conclusions This proof-of-concept study demonstrates the feasibility of longitudinal, enrichment-free single-cell liquid biopsy to monitor clonal heterogeneity, compartmental redistribution, and treatment-associated cellular dynamics during CAR-T therapy in mCRPC.
Molecular mimicry has emerged as a key mechanism linking microbial immunity to cancer immune surveillance, with growing evidence that microbial antigens can elicit T-cell responses cross-reactive with tumor-associated antigens. However, current interpretations remain largely antigen-centered, emphasizing structural similarities between individual epitopes. Here, we propose a broader conceptual framework in which molecular mimicry is viewed as the functional manifestation of a lifelong, cross-reactive memory T-cell repertoire shaped by infections, vaccination, microbiota, and environmental antigenic exposures. In this perspective, the critical determinant of tumor recognition is not simply antigen similarity, but whether the host immune repertoire has previously acquired the capacity to recognize the structural antigenic space occupied by tumor antigens. This shift moves the focus from the tumor to the host, positioning immune history as a central determinant of cancer immune surveillance. We discuss how this framework integrates diverse observations in cancer immunology and suggest that exploiting pre-existing immune memory may guide the development of improved biomarkers, cancer vaccines, and next-generation immunotherapies.
Background Esophageal squamous cell carcinoma (ESCC) is highly heterogeneous, leading to limited drug effectiveness and resistance. Antibody therapies offer limited benefits due to low response rates. Multispecific antibodies, targeting multiple tumor antigens and natural killer (NK)-cell receptors, may overcome these challenges, but their effectiveness in ESCC therapy is not yet understood.Methods Transcriptome sequencing and database analysis were performed on samples from patients with ESCC to identify tumor antigens. Multispecific antibodies were designed to target tumor antigens and NK-cell surface markers. Fast protein liquid chromatography and surface plasmon resonance were applied for quality control of antibodies. Using multiple ESCC cell lines and NK cells from different donors, flow cytometry was performed to assess NK cell cytotoxicity and activation. Immunofluorescence assays were used to confirm colocalization. Transcriptome sequencing, flow cytometry and western blots were performed to explore molecular mechanisms. Subcutaneous and metastatic xenograft tumor models were established to evaluate the in vivo antitumor efficacy of antibodies combined with adoptive transfer of NK cells.Results The expression of EGFR was consistently highly expressed in all ESCC samples, while MET was specifically upregulated in recurrent ESCC, whereas the database also validated two antigens overexpression in tumor tissues. Antibodies were successfully engineered for multiple antigens binding. The tetraspecific antibodies significantly enhanced NK-cell cytotoxicity by up to 30% against ESCC and paclitaxel-resistant cell lines compared with the NK-only group in vitro. Transcriptomic analysis and experimental validation revealed that antibodies triggered immune activation pathways and increased the expression of tumor necrosis factor-α, interferon-γ, and granzyme B in NK cells, but also induced NK cell exhaustion. In vivo, tetraspecific antibodies combined with NK cell infusions exerted superior antitumor efficacy, with an 82.3% tumor volume reduction in the early-stage model and 65.7% in the advanced-stage model compared with controls. The therapeutic efficacy was also observed in the metastatic tumor model. Meanwhile, the combination therapy was well tolerated, with enhanced NK cell infiltration in tumor tissues.Conclusions We developed tetraspecific antibodies to effectively bridge ESCC cells and NK cells. The antibodies have the potential to enhance the antitumor activity of NK cells against ESCC. This study supports the clinical translation of tetraspecific antibodies for NK cell-based immunotherapy for ESCC.
The immunosuppressive tumor microenvironment (TME) limits antigen presentation, immune trafficking, and therapeutic durability. Tumors range from immunoreactive microenvironments with pre-existing immune infiltration to immunosuppressive microenvironments characterized by myeloid-driven immunosuppression, dense stromal barriers, and effector T-cell exclusion. Intratumoral immunoadjuvants facilitate the transition of immunosuppressive TMEs toward immunoreactive states through activation of local innate immune signaling, chemokine-driven effector T-cell recruitment, and myeloid reprogramming, while amplifying pre-existing immunity in immunoreactive tumors. However, clinical translation is challenged by poor local retention and heterogeneous tumor architecture. This review integrates TME biology with advances in biomaterial-formulated delivery. Key immunoadjuvant classes, including STING, TLR, and RIG-I agonists, cytokines, and oncolytic viruses, are discussed with hydrogel depots, polymeric nanoparticles, and collagen-binding platforms that enhance retention and controlled release. Physical modulation through methods such as ultrasound and radiation is examined as a complementary approach to disrupt stromal barriers. A framework is proposed for matching immunoadjuvant class, biomaterial carrier, and dosing schedule to tumor-specific immunologic features that can drive lasting antitumor immunity.
The nervous system is increasingly recognized as an active regulatory layer of the tumor microenvironment. Tumors remodel local innervation, engage peripheral and central neural circuits, and mobilize neurotransmitters, neuropeptides, neurotrophic cues, and systemic neuroendocrine outputs that influence growth, invasion, immune evasion, therapeutic response, and toxicity. Tumor and stromal cells can also adopt neural-like phenotypes, extending tumor-neural communication beyond anatomically defined nerves. A unifying model is emerging: homeostatic neural inputs may support tissue integrity and immune surveillance, whereas tumor-activated or tumor-injured pathways can promote immune escape, dissemination, and immunotherapy resistance. This review follows that progression from tumor-induced neural remodeling and neural-like cell states to the sensory, autonomic, enteric, and systemic neuroendocrine axes that regulate antitumor immunity. We then consider how spatial omics resolves these interactions in situ and how neuroimmune pathways may be targeted to improve immunotherapy efficacy while limiting immune-related adverse events. Together, these advances position cancer neuroimmunology as a framework for interpreting tumor ecosystems and developing neuro-informed immunotherapies.
