Cancer cells are often addicted to serine synthesis to support growth. How serine synthesis is regulated in cancer is not well understood. We recently demonstrated protein arginine methyltransferase 1 (PRMT1) is upregulated in hepatocellular carcinoma (HCC) to methylate and activate phosphoglycerate dehydrogenase (PHGDH), thereby promoting serine synthesis. However, the mechanisms underlying PRMT1 upregulation and regulation of PRMT1-PHGDH axis remain unclear. Here, we show the E3 ubiquitin ligase F-box-only protein 7 (FBXO7) inhibits serine synthesis in HCC by binding PRMT1, inducing lysine 37 ubiquitination, and promoting proteosomal degradation of PRMT1. FBXO7-mediated PRMT1 downregulation cripples PHGDH arginine methylation and activation, resulting in impaired serine synthesis, accumulation of reactive oxygen species (ROS), and inhibition of HCC cell growth. Notably, FBXO7 is significantly downregulated in human HCC tissues, and inversely associated with PRMT1 protein and PHGDH methylation level. Overall, our study provides mechanistic insights into the regulation of cancer serine synthesis by FBXO7-PRMT1-PHGDH axis, and will facilitate the development of serine-targeting strategies for cancer therapy.

Background: Laparoscopic cholecystectomy (LC) is the gold standard for treating symptomatic gallstones but carries inherent risks like bile duct injury. While the critical view of safety (CVS) is advocated to mitigate bile duct injury, its real-world adoption is limited. Additionally, significant variations in surgeon performance impede procedural standardization, highlighting the need for a feasible, innovative, and effective training approach. The aim of this study is to develop an artificial intelligence (AI)-assisted coaching program for LC to enhance surgical education and improve surgeon’s performance. Materials and methods: The authors conducted a multicenter, randomized controlled trial from May 2022 to August 2023 to assess the impact of an AI-based coaching program, surgical coaching program, on novice performing LC. Surgeons and patients meeting specific inclusion criteria were randomly assigned to either a coaching group with AI-enhanced feedback or a self-learning group. The primary outcome was assessed using the Laparoscopic Cholecystectomy Rating Form, with secondary outcomes including surgical safety, efficiency, and adverse events. Statistical analyses were performed using SPSS, with significance set at a P-value less than 0.05. Results: Between May 2022 and August 2023, 22 surgeons were initially enrolled from 10 hospitals, with 18 completing the study. No demographic differences were noted between coaching and self-learning groups. In terms of surgical performance (Laparoscopic Cholecystectomy Rating Form scores), the coaching group showed significant improvement over time (31 to 40, P=0.008), outperforming the self-learning group by study end (40 vs 38, P=0.032). Significant improvements in CVS achievement were also noted in the coaching group (11% to 78%, P=0.021). Overall, the coaching program was well-received, outpacing traditional educational methods in both understanding and execution of CVS and participants in the intervention group expressed strong satisfaction with the program. Conclusions: The AI-assisted surgical coaching program effectively improved surgical performance and safety for novice surgeons in LC procedures. The model holds significant promise for advancing surgical education.

CD8⁺ T cell-based immune-therapeutics, including immune checkpoint inhibitors and adoptive cell therapies (tumor-infiltrating lymphocytes (TILs), T cell receptor-engineered T cells (TCR-T), chimeric antigen receptor T cells (CAR-T)), have achieved significant successes and prolonged patient survival to varying extents and even achieved cure in some cases. However, immunotherapy resistance and tumor insusceptibility frequently occur, leading to treatment failure. Recent evidences have highlighted the ponderance of tumor cells metabolic reprogramming in establishing an immunosuppressive milieu through the secretion of harmful metabolites, immune-inhibitory cytokines, and alteration of gene expression, which suppress the activity of immune cells, particularly CD8⁺ T cells to evade immune surveillance. Therefore, targeting tumor cell metabolic adaptations to reshape the immune microenvironment holds promise as an immunomodulatory strategy to facilitate immunotherapy. Here, we summarize recent advances in the crosstalk between immunotherapy and tumor reprogramming, focusing on the regulatory mechanisms underlying tumor cell glucose metabolism, amino acid metabolism, and lipid metabolism in influencing CD8⁺ T cells to provide promising metabolic targets or combinational strategies for immunotherapy.

BRAF V600E attracts wide attention in the treatment of colorectal cancer (CRC) as stratifying and predicting a refractory classification of CRC. Recent evidence indicates that Wnt/β‐catenin signaling is broadly activated and participates in the refractoriness of BRAF V600E CRC, but the underlying molecular mechanism needs to be elucidated. Here, heat shock 70 kDa protein 8 (HSPA8), an essential regulator in chaperone‐mediated autophagy (CMA), is identified as a potential therapeutic target for advanced BRAF V600E CRC. These results show that HSPA8 is transcriptionally upregulated in BRAF V600E CRC, which promotes CMA‐dependent degradation of caveolin‐1 (CAV1) to release β‐catenin into the nucleus and thus activates the Wnt/β‐catenin pathway, contributing to metastasis and progression of BRAF V600E CRC. Of note, HSPA8 directly interacts with the KIFSN motif on CAV1, the interaction can be enhanced by p38 MAPK‐mediated CAV1 S168 phosphorylation. Furthermore, pharmacological targeting HSPA8 by VER155008 exhibits synergistic effects with BRAF inhibitors on CRC mouse models. In summary, these findings discover the important role of the HSPA8/CAV1/β‐catenin axis in the development of refractory BRAF V600E CRC and highlight HSPA8 as a predictive biomarker and therapeutic target in clinical practice.

Extracellular vesicles (EVs) play a crucial role in triggering tumour‐aggressive behaviours. However, the energetic process by which tumour cells produce EVs remains poorly understood. Here, we demonstrate the involvement of β‐hexosaminidase B (HEXB) in mediating EV release in response to oxidative stress, thereby promoting the development of hepatocellular carcinoma (HCC). Mechanistically, reactive oxygen species (ROS) stimulate the nuclear translocation of transcription factor EB (TFEB), leading to the upregulation of both HEXB and its antisense lncRNA HEXB‐AS. HEXB‐AS can bind HEXB to form a protein/RNA complex, which elevates the protein stability of HEXB. The stabilized HEXB interacts with lysosome‐associated membrane glycoprotein 1 (LAMP1), disrupting lysosome‐multivesicular body (MVB) fusion, which protects EVs from degradation. Knockdown of HEXB efficiently inhibits EV release and curbs HCC growth both in vitro and in vivo. Moreover, targeting HEXB by M‐31850 significantly inhibits HCC growth, especially when combined with GW4869, an inhibitor of exosome release. Our results underscore the critical role of HEXB as a modulator that promotes EV release during HCC development.