Journal of Clinical Investigation最新文献

Cardiac allograft vasculopathy (CAV) is a fibroproliferative form of transplant rejection with limited treatment options other than retransplantation. In this issue, See and colleagues examined human explanted allografts with CAV. They found that a high proportion of intragraft plasma cells produce antibodies that recognize the heme catabolic end product, bilirubin. Clonotypic profiling revealed that bilirubin-reactive antibody-producing plasma cells develop from graft-infiltrating innate-like B cells, a subset often characterized by their rapid production of polyreactive natural antibodies as an early defense against infection. CAV but not nonrejecting graft tissue contained bilirubin deposits along with macrophages that expressed genes involved in heme catabolism. These findings raise the intriguing possibility that graft-derived bilirubin-specific antibodies target local heme catabolism to promote CAV.

TFE3 translocation renal cell carcinoma (tRCC), an aggressive kidney cancer driven by TFE3 gene fusions, is frequently misdiagnosed owing to morphologic overlap with other kidney cancer subtypes. Conventional liquid biopsy assays that detect tumor DNA via somatic mutations or copy number alterations are unsuitable for tRCC since it often lacks recurrent genetic alterations and because fusion breakpoints are highly variable between patients. We reasoned that epigenomic profiling could more effectively detect tRCC because the driver fusion constitutes an oncogenic transcription factor that alters gene regulation. By defining a TFE3-driven epigenomic signature in tRCC cell lines and detecting it in patient plasma using ChIP-seq, we distinguished tRCC from clear-cell RCC (AUC = 0.86) and samples of individuals without evidence of cancer (AUC = 0.92) at low tumor fractions (<1%). This work establishes a framework for noninvasive epigenomic detection, diagnosis, and monitoring of tRCC, with implications for other mutationally quiet, fusion-driven cancers.

Programmed cell death 1 ligand 1-targeted (PD-L1-targeted) immune checkpoint inhibitors are revolutionizing cancer therapy. However, strategies to induce endogenous PD-L1 degradation represent an emerging therapeutic paradigm. Here, we identified proanthocyanidins (PC) as a potent inducer of PD-L1 degradation through an endoplasmic reticulum-associated degradation (ERAD) mechanism. Mechanistically, PC exerted dual effects: First, it targeted and stabilized LKB1 to activate AMPK in tumor cells, subsequently inducing the phosphorylation of PD-L1 at Ser195 - a disruption that in turn impaired glycosylation of PD-L1 and promoted its retention in the ER. Second, PC directly bound to the E3 ubiquitin ligase SYVN1 to increase its protein stability, which strengthened PD-L1-SYVN1 binding, thereby accelerating K48-linked ubiquitination and proteasomal degradation of ER-retained PD-L1. This cascade culminated in the activation of CD8+ T cell-dominated antitumor immune responses, accompanied by suppression of myeloid-derived suppressor cells and regulatory T cells. In preclinical models of lung and colorectal cancer, PC exhibited synergistic antitumor efficacy when combined with anti-cytotoxic T lymphocyte antigen 4 (anti-CTLA-4) antibodies. Notably, PC also potently inhibited the progression of azoxymethane/dextran sodium sulfate-induced orthotopic colorectal cancer in mice. Collectively, our findings unveil an antitumor mechanism of PC, establishing this small-molecule compound as an ERAD pathway-exploiting immune checkpoint modulator with promising translational potential for cancer therapy.

Circadian clocks govern daily rhythms in cellular and physiological processes, including cell cycle, DNA repair, metabolism, and immune function, that influence cancer development and treatment response. Disruption of circadian regulators either promotes or suppresses malignancy depending on tumor type and biological context. This duality likely reflects systemic rewiring of circadian physiology and direct interactions between clock components and oncogenic pathways. These insights hold clinical relevance for the field of chronotherapy, which seeks to enhance therapeutic efficacy and minimize toxicity by aligning drug administration with circadian rhythms or by targeting elements of the molecular clock. In this Review, we highlight the promise of integrating circadian biology into precision oncology and underscore the importance of cancer type-specific investigations to harness the full therapeutic potential of chronotherapy in cancer.

A major unmet need in estrogen receptor-positive (ER+) breast cancer is understanding the mechanisms that underlie resistance to endocrine therapy. Although accumulating evidence suggests an association between the tumor immune microenvironment (TIME) and endocrine response, the specific role of the TIME in mediating endocrine resistance remains unclear. In this issue of the JCI, Napolitano et al. analyzed tumor biopsies from patients with ER+ breast cancer and reported that endocrine-resistant tumors exhibited heightened CD8+ T cell infiltration and activation of the CXCL11 - CXCR3/-7 axis. Spatial and coculture analyses of these tumors demonstrated that the CD8+ T cell-associated chemokine CXCL11 drove estrogen-independent tumor growth. These findings identify an immune-mediated mechanism of endocrine resistance in breast cancer and identify CXCL11 as a potential biomarker and therapeutic vulnerability.

SCN8A encodes the voltage-gated sodium channel Nav1.6, which plays a key role in facilitating neuronal excitability. Mutations in SCN8A, particularly gain-of-function variants, cause SCN8A developmental and epileptic encephalopathy (DEE), a severe epilepsy syndrome characterized by seizures, cognitive dysfunction, movement disorders, and sudden unexpected death in epilepsy (SUDEP). The recurrent SCN8A variant R1872W impairs channel inactivation, causing neuronal hyperexcitability and seizures. Current treatments, including antiseizure medications, are often ineffective for patients with SCN8A DEE, highlighting the need for targeted therapies. We employed base editing to correct the R1872W SCN8A variant. An adenine base editor and guide RNA (SCN8A-ABE) were packaged within dual PhP.eB-adeno-associated viruses (AAVs) and administered to R1872W mice at P2. SCN8A-ABE significantly increased survival of mice expressing R1872W and either reduced seizure incidence and severity or eliminated seizure occurrence. Electrophysiological recordings revealed a rescue of seizure-associated neuronal hyperexcitability and suppression of the pathogenic persistent sodium current (INaP) in treated mice. Comorbidities, including diminished mobility and anxiety-like behaviors, were improved by SCN8A-ABE. These effects were achieved by a 32% absolute reduction in mutant transcripts, accompanied by conversion to SCN8A WT transcripts. Our findings demonstrate base editing as an effective targeted therapeutic approach for SCN8A DEEs by addressing the underlying genetic cause.

Circulating tumor DNA detection in renal cell carcinoma has long been limited by the disease's low DNA shedding. An aggressive subtype termed translocation renal cell carcinoma (tRCC) is notably more difficult to detect than the common type, clear-cell RCC, in part due to interindividual variability of gene fusions of the transcription factor TFE3, the driving factor in tRCC. In this issue of the JCI, Garinet et al. reported on an epigenomic liquid biopsy approach that identified a TFE3 fusion-associated chromatin signature specific to tRCC. This work demonstrated that fusion-driven epigenomic alterations can be captured noninvasively and used to distinguish tRCC from other renal cancer subtypes. Beyond its diagnostic potential, the approach described by Garinet et al. may enable disease monitoring and subtype classification in other genetically quiet tumors. Epigenomic liquid biopsy is a promising framework to improve diagnostic accuracy and guide personalized management for tRCC.

Cells release extracellular vesicles (EVs) with cargo that originates from distinct subcellular compartments, including the nucleus, cytoplasm, and plasma membrane. Given their diverse cargo, EVs play multiple roles in physiology and pathology, including in immune dysregulation and autoimmune pathogenesis. For example, EVs can act as autoantigens by transporting immunogenic molecules from the nucleus or cytoplasm, whereas EVs carrying membrane-bound MHCs from antigen-presenting cells can activate adaptive immunity by presenting self-antigens to T cells. EV-associated cytoplasmic peptidases or proteasomes contribute to immune regulation by modulating antigen processing and presentation. Moreover, EVs also drive inflammatory responses by shuttling a variety of proinflammatory molecules that sustain autoimmune responses. Intriguingly, emerging evidence indicates that EVs might contribute to autoimmune surveillance by activating cytosolic surveillance sensors, modulating immune checkpoints, regulating NK/T cell cytotoxicity, and altering macrophage and DC phagocytosis, representing an exciting and underexplored frontier in autoimmune research. By tackling critical knowledge gaps, this Review explores the emerging roles of EVs and their diverse cargo in driving autoimmune diseases, suggesting new perspectives on their potential as innovative therapeutic targets.

CRISPR/Cas9 base editing holds the potential to treat disease caused by single-nucleotide variants. In contrast with conventional CRISPR/Cas9 approaches, base editing enzymatically induces precise DNA alterations and can directly correct disease-causing variants. In this issue of JCI, Reever et al. used base editing to treat a mouse model of a severe neurodevelopmental disorder caused by a pathogenic missense variant in the voltage-gated sodium channel gene SCN8A. This work represents a starting point for the further refinement of base editing to treat genetic epilepsy.