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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), the most common type of liver tumor, is a leading cause of cancer-related deaths, and the incidence of liver cancer is still increasing worldwide. Curative hepatectomy or liver transplantation is only indicated for a small population of patients with early-stage HCC. However, most patients with HCC are not candidates for radical resection due to disease progression, leading to the choice of the conventional tyrosine kinase inhibitor drug sorafenib as first-line treatment. In the past few years, immunotherapy, mainly immune checkpoint inhibitors (ICIs), has revolutionized the clinical strategy for HCC. Combination therapy with ICIs has proven more effective than sorafenib, and clinical trials have been conducted to apply these therapies to patients. Despite significant progress in immunotherapy, the molecular mechanisms behind it remain unclear, and immune resistance is often challenging to overcome. Several studies have pointed out that the complex intercellular communication network in the immune microenvironment of HCC regulates tumor escape and drug resistance to immune response. This underscores the urgent need to analyze the immune microenvironment of HCC. This review describes the immunosuppressive cell populations in the immune microenvironment of HCC, as well as the related clinical trials, aiming to provide insights for the next generation of precision immunotherapy., Competing Interests: YF, XG, LS, TC, CW, JW, YL, LL No competing interests declared, (© 2024, Fu, Guo et al.)

As a crucial protumorigenic long noncoding RNA, colorectal tumor differential expression (CRNDE) has been confirmed to facilitate the progression of various cancers. However, its role in the tumor microenvironment (TME) of hepatocellular carcinoma (HCC) is still unclear. Here we determined that CRNDE was upregulated in HCC samples and that CRNDE-positive cells were predominantly enriched in malignant tumor cells. In vivo functional assays revealed that CRNDE-induced tumor cells supported HCC progression, recruited abundant granulocyte myeloid-derived suppressor cells (G-MDSCs) and restricted the infiltration of T cells. In terms of mechanisms, CRNDE bound with Toll-like receptor 3 (TLR3) and activated NF-κB signaling to increase the secretion of c-x-c motif chemokine ligand 3 (CXCL3). CRNDE knockdown could significantly suppress the accumulation of G-MDSCs and enhance the infiltration of T cells in the TME of HCC in vivo. Taken together, our study reveals the CRNDE-NF-κB-CXCL3 axis plays a crucial role in driving the immunosuppressive niche to facilitate HCC progression by recruiting G-MDSCs., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)