Pyroptosis is a type of programmed cell death characterized by the activation of inflammatory caspases and the cleavage of gasdermin proteins. Pyroptosis can suppress tumor development and induce antitumor immunity, and activating pyroptosis is a potential treatment strategy for cancer. To uncover approaches to harness the anticancer effects of pyroptosis, we aimed to identify regulators of pyroptosis in cancer. A CRISPR-Cas9 screen identified that loss of USP48, a deubiquitinating enzyme, significantly inhibited cell pyroptosis. USP48 promoted pyroptosis by stabilizing gasdermin E (GSDME). USP48 bound GSDME and removed K48-linked ubiquitination at positions K120 and K189. Clinical tissue testing confirmed that the expression of USP48 positively correlated with GSDME and pyroptosis-related factors. Single-cell sequencing showed that the functions of T cells and tumor-associated macrophages in the tumor microenvironment were inhibited after USP48 knockout. Finally, overexpression of USP48 enhanced the therapeutic efficacy of programmed cell death protein 1 inhibitors in tumors in mouse models. Together, these findings define a pyroptosis regulation pathway and indicate that pharmacologic activation of USP48 may provide an effective strategy to sensitize cancer cells to pyroptosis and improve response to immunotherapy. Significance: USP48 promotes pyroptosis by deubiquitinating GSDME and enhances antitumor immunity, indicating that increasing USP48 activity may be a future therapeutic strategy for treating cancer.

Radiotherapy effectiveness in breast cancer is limited by radioresistance. Nevertheless, the mechanisms behind radioresistance are not yet fully understood. RUVBL1 and RUVBL2, referred to as RUVBL1/2, are crucial AAA+ ATPases that act as co-chaperones and are connected to cancer. Our research revealed that RUVBL1, also known as pontin/TIP49, is excessively expressed in MMTV-PyMT mouse models undergoing radiotherapy, which is considered a murine spontaneous breast-tumor model. Our findings suggest that RUVBL1 enhances DNA damage repair and radioresistance in breast cancer cells both in vitro and in vivo. Mechanistically, we discovered that DTL, also known as CDT2 or DCAF2, which is a substrate adapter protein of CRL4, promotes the ubiquitination of RUVBL1 and facilitates its binding to RUVBL2 and transcription cofactor β-catenin. This interaction, in turn, attenuates its binding to acetyltransferase Tat-interacting protein 60 (TIP60), a comodulator of nuclear receptors. Subsequently, ubiquitinated RUVBL1 promotes the transcriptional regulation of RUVBL1/2-β-catenin on genes associated with the non-homologous end-joining (NHEJ) repair pathway. This process also attenuates TIP60-mediated H4K16 acetylation and the homologous recombination (HR) repair process. Expanding upon the prior study’s discoveries, we exhibited that the ubiquitination of RUVBL1 by DTL advances the interosculation of RUVBL1/2-β-catenin. And, it then regulates the transcription of NHEJ repair pathway protein. Resulting in an elevated resistance of breast cancer cells to radiation therapy. From the aforementioned, it is evident that targeting DTL-RUVBL1/2-β-catenin provides a potential radiosensitization approach when treating breast cancer.

CD8+ tissue-resident memory T (Trm) cells and tumor-infiltrating lymphocytes (TIL) regulate tumor immunity and immune surveillance. Characterization of Trm cells and TILs could help identify potential strategies to boost antitumor immunity. Here, we found that the transcription factor SCML4 was required for the progression and polyfunctionality of Trm cells and was associated with a better prognosis in patients with cancer. Moreover, SCML4 maintained multiple functions of TILs. Increased expression of SCML4 in CD8+ cells significantly reduced the growth of multiple types of tumors in mice, while deletion of SCML4 reduced antitumor immunity and promoted CD8+ T-cell exhaustion. Mechanistically, SCML4 recruited the HBO1–BRPF2–ING4 complex to reprogram the expression of T cell–specific genes, thereby enhancing the survival and effector functions of Trm cells and TILs. SCML4 expression was promoted by fatty acid metabolism through mTOR–IRF4–PRDM1 signaling, and fatty acid metabolism–induced epigenetic modifications that promoted tissue-resident and multifunctional gene expression in Trm cells and TILs. SCML4 increased the therapeutic effect of anti–PD-1 treatment by elevating the expression of effector molecules in TILs and inhibiting the apoptosis of TILs, which could be further enhanced by adding an inhibitor of H3K14ac deacetylation. These results provide a mechanistic perspective of functional regulation of tumor-localized Trm cells and TILs and identify an important activation target for tumor immunotherapy. Significance: SCML4 upregulation in CD8+ Trm cells and tumor-infiltrating lymphocytes induced by fatty acid metabolism enhances antitumor immune responses, providing an immunometabolic axis to target for cancer treatment. See related commentary by Chakraborty et al., p. 3321

Nonalcoholic steatohepatitis (NASH) is a chronic, inflammatory form of nonalcoholic fatty liver disease (NAFLD) that frequently progresses to cirrhosis and hepatocellular carcinoma (HCC). However, the role of various immune cells in switching from NAFLD to NASH remains elusive. Here, we took an unbiased single-cell assay for transposase accessible chromatin sequencing (scATAC-seq) approach to investigate the cellular composition, gene expression profiling, and causative roles of immune cells in NASH development. T helper 17 (T _H 17) cells were identified as the most abundant subpopulation of immune cells in mouse livers with NASH. Further analysis of scATAC-seq data and single-cell RNA sequencing (scRNA-seq) data from the GEO database showed that human immunodeficiency virus type I enhancer binding protein 1 (HIVEP1) is a critical transcription factor (TF) regulating T _H 17 cell differentiation and cytokine production. Specific knockout of Hivep1 in IL-17A ⁺ and CD4 ⁺ T cells in mice showed impairment of T _H 17 cell differentiation and alleviation of NASH development. Mechanistically, HIVEP1 transcriptionally regulated ornithine decarboxylase 1 (ODC1), the rate-limiting enzyme of polyamine metabolism, to modulate T _H 17 cell differentiation and cytokine production. Consequently, pharmacological inhibition of ODC1 decreased cytokine production, alleviated inflammation, and prevented the NAFLD-to-NASH transition. Together, our findings elucidate the role of polyamine metabolism in T _H 17 cell–mediated NASH development and identify potential therapeutic targets for the effective treatment of NASH.

A central hurdle limiting the success of T‐cell‐based immunotherapies is the progressive dysfunction of T cells, known as exhaustion. Overcoming this exhausted state is therefore a pivotal objective in translational oncology and immunology. The advent of single‐cell multiomics has fundamentally revised the once‐prevailing view of exhaustion as a uniform endpoint. Instead, it is now recognised as a dynamic differentiation process comprising a spectrum of distinct cellular states. This spectrum is organised along a hierarchical axis, originating from progenitor‐exhausted (Tpex) cells that retain proliferative potential and advancing towards terminally exhausted (Tex) populations with severely impaired effector functions. We undertake a comprehensive synthesis of multiomics data—spanning transcriptomic, epigenomic, metabolomic, proteomic and posttranslational modification (PTM)‐proteomic layers—to decipher the interconnected regulatory programmes that dictate commitment along this exhaustion axis. From this integrated analysis, we derive a unified mechanistic framework that delineates the molecular drivers of Tpex cell fate determination and terminal exhaustion. Beyond its explanatory power for basic biology, this framework serves as a direct roadmap for therapeutic innovation, highlighting novel nodes for intervention aimed at reinvigorating the exhausted T‐cell compartment. The practical application of these insights holds significant promise for enhancing the efficacy of established current immunotherapeutic platforms. Key points: This review is the first to integrate multi‐omics evidence for constructing a dynamic regulatory map of T‐cell exhaustion. It highlights the critical cross‐omics synergistic mechanisms, such as metabolic reprogramming influencing epigenetic remodeling to drive cell fate. The multi‐omics perspective presented directly informs novel therapeutic strategies.