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Despite the importance of spliceosome core components in cellular processes, their roles in cancer development, including hepatocellular carcinoma (HCC), remain poorly understood. In this study, we uncover a critical role for SmD2, a core component of the spliceosome machinery, in modulating DNA damage in HCC through its impact on BRCA1/FANC cassette exons and expression. Our findings reveal that SmD2 depletion sensitizes HCC cells to PARP inhibitors, expanding the potential therapeutic targets. We also demonstrate that SmD2 acetylation by p300 leads to its degradation, while HDAC2-mediated deacetylation stabilizes SmD2. Importantly, we show that the combination of Romidepsin and Olaparib exhibits significant therapeutic potential in multiple HCC models, highlighting the promise of targeting SmD2 acetylation and HDAC2 inhibition alongside PARP inhibitors for HCC treatment. The relevance of spliceosome core components in cancer is less understood. Here the authors show SmD2, a core component of the spliceosome machinery, is under acetylation-dependent regulation, which could be targeted to enhance sensitivity to PARP inhibitors in hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer with a highly immunosuppressive tumor microenvironment and a typical pattern of disturbances in hepatic lipid metabolism. Long non‐coding RNAs are shown to play an important role in the regulation of gene expression, but much remains unknown between tumor microenvironment and lipid metabolism as a bridging molecule. Here, long intergenic nonprotein coding RNA 01116 (LINC01116) acts as this molecular which is frequently upregulated in HCC patients and associated with HCC progression in vitro and in vivo is identified. Mechanistically, LINC01116 stabilizes EWS RNA‐binding protein 1 (EWSR1) by preventing RAD18 E3 Ubiquitin Protein Ligase (RAD18) ‐mediated ubiquitination. The enhanced EWSR1 protein upregulates peroxisome proliferator activated receptor alpha (PPARA) and fatty acid binding protein1 (FABP1) expression, a long‐chain fatty acid (LCFA) transporter, and thus cancer cells outcompete T cells for LCFAs, especially linoleic acid, for seeding their own growth, leading to T cell malfunction and HCC malignant progression. In a preclinical animal model, the blockade of LINC01116 leads to enhanced efficacy of anti‐PD1 treatment accompanied by increased cytotoxic T cell and decreased exhausted T cell infiltration. Collectively, LINC01116 is an immunometabolic lncRNA and the LINC01116‐EWSR1‐PPARA‐FABP1 axis may be targetable for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) remains a global challenge. Finding new specific targets has significant clinical value for the treatment of hepatocellular carcinoma. In this study, we discovered a new biomarker targeting HCC. At present, the role of Inner Membrane Mitochondrial Protein (IMMT) in various malignant tumors is receiving increasing attention, but its molecular mechanism of action in the malignant process of HCC has not been fully elucidated. This study aims to investigate the key regulatory mechanisms of IMMT in the formation of HCC. Using TCGA data and clinical HCC samples, we first studied the expression of IMMT in HCC tissues and its correlation with malignant prognosis of patients. The regulatory effect of IMMT on HCC was studied by lentivirus infection. In vitro, the effects of IMMT on the proliferation, migration and apoptosis of cells were investigated by CCK8, colony formation assay, transwell and flow cytometry. Consistently, in vivo experiments, the regulation of tumor growth by IMMT was studied by constructing subcutaneous transplanted tumor and liver carcinoma in situ. In terms of mechanism, we predicted and verified the downstream genes of IMMT with the help of string database. We found that IMMT was significantly up-regulated in HCC tissues and was significantly positively correlated with poor prognosis of patients. Functionally, we demonstrated that IMMT knockdown significantly inhibited HCC cell proliferation, migration and promoted cell apoptosis in vitro. Similarly, the knockdown of IMMT also significantly weakened the progression of tumors in vivo. In terms of mechanism, we demonstrate for the first time that IMMT can regulate the progression of HCC by influencing the activation of PI3K-AKT-mTOR pathway. Collectively, our research findings elucidate the hitherto unexplored important role of the IMMT/PI3K/AKT/mTOR axis in the formation of HCC, and provide a new biomarker for clinical diagnosis and treatment of HCC. [ABSTRACT FROM AUTHOR]