Search

DNA damage repair (DDR) plays a pivotal role in hepatocellular carcinoma (HCC), driving oncogenesis, progression, and therapeutic response. However, the mechanisms of DDR mediated immune cells and immuno-modulatory pathways in HCC are yet ill-defined. Our study introduces an innovative deep machine learning framework for precise DDR assessment, utilizing single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data. Single-cell RNA sequencing data were obtained and in total 85,628 cells of primary or post-immunotherapy cases were analyzed. Large-scale HCC datasets, including 1027 patients in house together with public datasets, were used for 101 machine-learning models and a novel DDR feature was derived at single-cell resolution (DDRscore). Druggable targets were predicted using the reverse phase protein array (RPPA) proteomic profiling of 169 HCC patients and RNA-seq data from 22 liver cancer cell lines. Our investigation reveals a dynamic interplay of DDR with natural killer cells and B cells in the primary HCC microenvironment, shaping a tumor-promoting immune milieu through metabolic programming. Analysis of HCC post-immunotherapy demonstrates elevated DDR levels that induces epithelial-mesenchymal transition and fibroblast-like transformation, reshaping the fibrotic tumor microenvironment. Conversely, attenuated DDR promotes antigen cross-presentation by dendritic cells and CD8+ T cells, modulating the inflammatory tumor microenvironment. Regulatory network analysis identifies the CXCL10-CXCR3 axis as a key determinant of immunotherapeutic response in low DDR HCC, potentially regulated by transcription factors GATA3, REL, and TBX21. Using machine learning techniques by combining bulk RNA-seq data in house together with public datasets, we introduce DDRscore, a robust consensus DDR scoring system to predict overall survival and resistance to PD-1 therapy in HCC patients. Finally, we identify BRAF as a potential therapeutic target for high DDRscore patients. Our comprehensive findings advance our understanding of DDR and the tumor microenvironment in HCC, providing insights into immune regulatory mechanisms mediated via DDR pathways. • The study integrates multiple omics analyses to depict the heterogeneity of the tumor microenvironment (TME) in hepatocellular carcinoma (HCC) under different DDR statuses, both pre- and post- immunotherapy. • DDR scoring framework is developed using advanced machine learning algorithms, enabling accurate assessment of DDR levels in HCC. • Potential therapeutic targets (BRAF) was identified specifically for patients with high DDR status, offering promising avenues for personalized treatment in HCC. [ABSTRACT FROM AUTHOR]

The overexpression of the MDM2 oncoprotein frequently occurs in hepatocellular carcinoma (HCC). Small molecules that inhibit MDM2-p53 binding show efficacy against p53 wild-type HCC, but most patients have p53-mutant tumors and intrinsic resistance to such MDM2 inhibitors. We have recently discovered that the NFAT1 transcription factor upregulates MDM2 expression, but the role of NFAT1 in HCC is not fully understood. The present study was designed to develop a dual-targeting (MDM2 and NFAT1) strategy for the treatment of HCC. We herein demonstrate that high expression levels of NFAT1 and MDM2 are independent predictors of a poor prognosis in patients with HCC. We have also identified a MDM2 and NFAT1 dual inhibitor (termed MA242) that induces MDM2 auto-ubiquitination and degradation and represses NFAT1-mediated MDM2 transcription. MA242 profoundly inhibits the growth and metastasis of HCC cells in vitro and in vivo, independent of p53. The present efficacy and mechanistic studies provide proof-of-principle data to support the therapeutic value of this dual targeting strategy in future drug discovery. [ABSTRACT FROM AUTHOR]

Evading immune destruction is an emerging hallmark of cancer and a potential key step in tumorigenesis. Immune checkpoint blocker (ICB)-based combination therapies revolutionize the landscape of systemic therapy for HCC. However, the molecular underpinnings governing immune evasion and responses remain unclear. Our study aims to find new regulatory molecules that drive HCC immune escape and tumorigenesis and find new promising immunotherapeutic approaches for HCC. In our study, laser capture microdissection (LCM) and miRNA sequencing combined with in vitro and in vivo experiment s identified miR-93-5p as a crucial initiating oncogene during liver progenitor cell (LPC) malignant transformation and immune escape. Mechanistically, miR-93-5p could directly target canonical tumour suppressors such as APC to promote LPC malignant transformation and hepatocarcinogenesis. More importantly, miR-93-5p could induce deviant GAL-9 augmentation to inactivate infiltrated CD8(+) T cells and induce immune evasion by targeting several epigenetic regulators, such as AEBP2, and then regulating H3K4me3/H3K27me3 bivalency. Experiments in C57BL/6 mice demonstrated that blockade of Gal-9 abrogated miR-93-5p-induced HCC progression and improved their prognosis. Clinically, we identified a unique subtype of HCC closely associated with high GAL-9 expression and anti-PD1 treatment resistance. Our study highlights the pivotal role of the miR-93-5p/Gal-9 axis in driving HCC immune escape and tumorigenesis. Blocking GAL-9 is an effective and promising immunotherapeutic approach for HCC. • miR-93-5p was demonstrated to be a crucial initiating oncogene during liver progenitor cell (LPC) malignant transformation. • miR-93-5p could directly target several tumour suppressors to promote LPC malignant transformation and hepatocarcinogenesis. • miR-93-5p induced GAL-9 augmentation to inactivate infiltrated CD8(+) T cells and induce immune evasion. • Blockade of Gal-9 abrogated miR-93-5p-induced HCC progression and improved animals prognosis. • A unique subtype of HCC was identified to be closely associated with high GAL-9 expression and anti-PD1 treatment resistance. [ABSTRACT FROM AUTHOR]

MiRNA-30a (miR-30a) was previously reported as one of metastatic hepatocellular carcinoma (HCC)-related microRNAs. However, the function of miR-30a on enhancing our biological understanding of HCC metastasis is not clear. This study demonstrated that miR-30a was significantly down-regulated in HCC tissues and cell lines, and was associated with vascular invasion, metastasis potential and recurrent disease in HCC. Functional studies confirmed that miR-30a could inhibit the metastasis of HCC in a well-established nude mouse model of lung metastasis. Moreover, miR-30a was proved to prevent anoikis inhibition of HCC cells in vivo and in vitro. Mechanically, autophagy related protein Beclin 1 and Atg5 were direct downstream targets of miR-30a, and mediated autophagy activity influence of miR-30a in HCC. Taken together, downregulated miR-30a in metastatic HCC mediates Beclin 1 and Atg5-dependent autophagy, which confers anoikis resistance in HCC cells. The molecular basis of autophagy action during this process partly contributes to the HCC metastasis, suggesting that targeting autophagy via miR-30a may have therapeutic implications for the prevention of HCC recurrence/metastasis. [ABSTRACT FROM AUTHOR]

Upregulation of CXCR2 in tumor cells has been documented in several types of cancer. As one of its ligands, CXCL5 is associated with neutrophil infiltration and poor prognosis in hepatocellular carcinoma (HCC). However, little is known about the role of the CXCR2/CXCL5 axis in the invasion and metastasis of HCC cells. In this study, we examined CXCR2 expression in human HCC cell lines and in three independent cohorts of HCC patients. The molecular effects of high expression levels of CXCR2 and CXCL5 in HCC cells were determined using qRT-PCR, western blot analysis, immunofluorescence, matrigel invasion assay, and xenograft mouse models. We found that high levels of CXCR2 correlated with progression and poor prognosis in human HCC. CXCR2/CXCL5 together promoted cell spreading by inducing the epithelial–mesenchymal transition (EMT) through activation of the PI3K/Akt/GSK-3β/Snail signaling pathway. In clinical HCC samples, high expression of both CXCR2 and CXCL5 showed a significant correlation with the activation of PI3K/Akt/GSK-3β/Snail signaling and EMT phenotype. In conclusion, our data showed that the CXCR2/CXCL5 axis contributes to EMT of HCC cells through activating PI3K/Akt/GSK-3β/Snail signaling, and it may serve as a potential therapeutic target. [ABSTRACT FROM AUTHOR]