Radiotherapy is a mainstay of cancer treatment, yet its efficacy is still substantially restricted due to radioresistance. The mechanisms underlying radioresistance remain elusive, impeding drug development and therapeutics. Here, using a high-throughput random gene perturbation method based on piggyBac transposon, we screened and identified CABLES1, an adaptor protein, as a key regulator of tumor radioresistance. The function of CABLES1 in radioresistance was further validated in multiple human cell lines in vitro and a mouse xenograft model in vivo. High expression of CABLES1 is significantly correlated with radioresistance in cancer patients. Mechanistically, CABLES1 interacts with XRCC6/XRCC5 heterodimer and activates DNA-PKcs by promoting DNA-PK holoenzyme formation, thus facilitating the efficiency of nonhomologous end-joining (NHEJ) repair and radioresistance. Notably, YTHDF1 recognizes METTL14-deposited m6A modification on CABLES1 mRNA to enhance its translation in response to ionizing radiation (IR), thereby sustaining the elevation of NHEJ repair capacity and radioresistance. Through high-throughput screening of a small molecule library, we showed that theaflavin 3,3'-digallate (TF-3) specifically disrupts the CABLES1-XRCC6 interaction, thereby sensitizing cancer cells to radiotherapy. Together, our study unveils the molecular mechanism by which CABLES1 potentiates tumor radioresistance, providing a novel synthetic lethal strategy for targeting cancer.

Iron is indispensable for various biological processes, among which erythropoiesis is a privileged iron consumer to synthesize hemoglobin. FAM96A, also known as cytosolic iron-sulfur protein assembly 2 A (CIA2A), is a conserved protein involved in cytosolic iron-sulfur cluster assembly but also harboring a canonical signal peptide for secretion. Here, we unveil a previously unrecognized role of autocrine FAM96A in maintaining iron homeostasis and erythroid differentiation. Fam96a-/- mice exhibit anemia with impaired recovery, featuring arrested erythroblast differentiation and blocked CD71+Ter119- to CD71+Ter119+ transition. Notably, Fam96a-/- bone marrow and spleen cells exhibit iron overload, elevated oxidative stress, and ferroptosis, all of which are rescued by FAM96A protein application. Mechanistically, secreted FAM96A binds TFRC extracellular domain, reducing TFRC-transferrin binding affinity to limit excessive iron uptake. Our findings identify FAM96A as a novel regulator of TFRC-dependent iron homeostasis, providing insights into erythropoietic disorders and therapeutic strategies.

Hepatitis B virus (HBV) infection remains a leading etiological driver of hepatocellular carcinoma (HCC). Cuproptosis is a recently defined copper-dependent form of regulated cell death that selectively eliminates mitochondria-dependent cells; whether HBV rewires this vulnerability remains unknown. Here we unveil a novel HBV X protein (HBx)-driven mechanism of cuproptosis evasion. Integrative analysis of clinical specimens, HBx-transgenic (HBx-Tg) mice, and multi-omics datasets revealed marked downregulation of STEAP4 (six-transmembrane epithelial antigen of prostate 4), a metalloreductase essential for cuproptosis sensitivity, in HBV-positive HCC. Mechanistically, HBx attenuates sirtuin 3 (SIRT3), impairing deacetylation of STEAP4 at lysine 404 and abolishing its mitochondrial targeting. Consequently, cells switch from the tricarboxylic acid (TCA) cycle respiration to glycolysis, reducing sensitivity to the copper ionophore elesclomol (ES). Restoring STEAP4 expression or pharmacological activation of SIRT3 with honokiol (HKL) re-instated mitochondrial STEAP4 localization and re-sensitized HBV-related HCC cells to cuproptosis; combination with ES produced synergistic tumor suppression in vitro and in orthotopic models. Collectively, our findings establish the SIRT3-STEAP4 axis as a novel regulator of cuproptosis resistance in HBV-related HCC. HBx-mediated repression of SIRT3 disrupts STEAP4 deacetylation and mitochondrial targeting, fostering metabolic reprogramming and evasion of copper-induced cell death. The results provide a pre-clinical rationale for copper-directed combination strategies in HBV-associated HCC.

Diabetic complications frequently arise in mechanically stressed regions, yet the molecular links between biomechanical forces and metabolic dysfunction remain unclear. Here, we demonstrate that mechanical stress induces glucose accumulation and downstream metabolic stress in keratinocytes. Mechanistically, Piezo1 activation led to intracellular glucose overload and advanced glycation end-products (AGEs) accumulation, which induced mitochondrial DNA (mtDNA) leakage into the cytosol and subsequently activated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling cascade (cGAS-STING pathway). Keratinocyte-specific Piezo1 deletion markedly reduced AGEs accumulation and preserved mitochondrial integrity, and STING ablation exhibited similar downstream protective effects. Notably, we identify Cortistatin (CST), an endogenous neuropeptide, as a previously unrecognized inhibitory ligand of Piezo1. CST binding attenuates calcium influx and glucose accumulation under mechanical stress, conferring notable protection in vitro and in diabetic ulcers (DUs) models. These findings uncover a CST-Piezo1-STING regulatory axis that integrates mechanical and metabolic cues to drive keratinocyte dysfunction in diabetes.

Temporal lobe epilepsy (TLE) is the most common and severe form of epilepsy in adults; however, the underlying pathological mechanisms remain unclear. Post-translational modifications (PTMs) of proteins are increasingly recognized to contribute to the development and maintenance of epilepsy; however, the functional significance of lysine crotonylation (Kcr) in epilepsy formation is still unclear. Herein we found that high levels crotonylation promote seizure susceptibility. Through quantitative analysis of global crotonylome in the hippocampus of control and epileptic mice, we identified a significant decrease in K98 crotonylation (K98cr) of syntaxin-binding protein 1 (STXBP1) in epileptic mice hippocampus. In Stxbp1K98Q knock-in mice, the upregulation of STXBP1 K98cr reduces the binding with syntaxin-1B(STX1B), leading to a decreased assembly of soluble NSF attachment protein receptors (SNAREs) in presynaptic active zone and subsequent inhibition vesicle release, thereby promoting epilepsy formation. Additionally, we found that reduced E1A-binding protein p300 (p300)-mediated crotonylation is a major cause of the altered STXBP1 crotonylation in the hippocampus of epileptic mice. Furthermore, chemically inhibiting the generation of crotonyl-CoA alleviate the seizure susceptibility of mice. In summary, our results indicate that crotonylation is an important regulatory factor in the process of epilepsy formation and modulating crotonylation may provide new insights for epilepsy treatment.