NRAV promotes HCC stemness via the m6A-regulated let-7c-5p/LIN28B axis.

PurposeN6-methyladenosine (m6A) modification has shown critical roles in regulating mRNA fate. Non-coding RNAs also have important roles in various diseases, including hepatocellular carcinoma (HCC). However, the potential influences of m6A modification on non-coding RNAs are still unclear. In this study, we identified a novel m6A-modified ATP8B1-AS1 and aimed to investigate the effects of m6A on the expression and role of ATP8B1-AS1 in HCC.MethodsqPCR was performed to measure the expression of related genes. The correlation between gene expression and prognosis was analyzed using public database. m6A modification level was measured using MeRIP and single-base elongation- and ligation-based qPCR amplification method. The roles of ATP8B1-AS1 in HCC were investigated using in vitro and in vivo functional assays. The mechanisms underlying the roles of ATP8B1-AS1 were investigated by ChIRP and ChIP assays.ResultsATP8B1-AS1 is highly expressed in HCC tissues and cell lines. High expression of ATP8B1-AS1 is correlated with poor overall survival of HCC patients. ATP8B1-AS1 is m6A modified and the 792 site of ATP8B1-AS1 is identified as an m6A modification site. m6A modification increases the stability of ATP8B1-AS1 transcript. m6A modification level of ATP8B1-AS1 is increased in HCC tissues and cell lines, and correlated with poor overall survival of HCC patients. ATP8B1-AS1 promotes HCC cell proliferation, migration, and invasion, which were abolished by the mutation of m6A-modified 792 site. Mechanistic investigation revealed that m6A-modified ATP8B1-AS1 interacts with and recruits m6A reader YTHDC1 and histone demethylase KDM3B to MYC promoter region, leading to the reduction of H3K9me2 level at MYC promoter region and activation of MYC transcription. Functional rescue assays showed that depletion of MYC largely abolished the oncogenic roles of ATP8B1-AS1.Conclusionm6A modification level of ATP8B1-AS1 is increased and correlated with poor prognosis in HCC. m6A-modified ATP8B1-AS1 exerts oncogenic roles in HCC via epigenetically activating MYC expression.

Hepatocellular carcinoma (HCC) represents a major global health threat with diverse and complex pathogenesis. Aldo–keto reductase family 1 member B10 (AKR1B10), a tumor-associated enzyme, exhibits abnormal expression in various cancers. However, a comprehensive understanding of AKR1B10's role in HCC is lacking. This study aims to explore the expression characteristics of AKR1B10 in HCC and its correlation with clinicopathological features, survival prognosis, and tumor immune microenvironment, further investigating its role and potential regulatory mechanisms in HCC. This study conducted comprehensive analyses using various bioinformatics tools and databases. Initially, differentially expressed genes related to HCC were identified from the GEO database, and the expression of AKR1B10 in HCC and other cancers was compared using TIMER and GEPIA databases, with validation of its specificity in HCC tissue samples using the HPA database. Furthermore, the relationship of AKR1B10 expression with clinicopathological features (age, gender, tumor size, staging, etc.) of HCC patients was analyzed using the TCGA database's LIHC dataset. The impact of AKR1B10 expression levels on patient prognosis was evaluated using Kaplan–Meier survival analysis and the Cox proportional hazards model. Additionally, the correlation of AKR1B10 expression with tumor biology-related signaling pathways and tumor immune microenvironment was studied using databases like GSEA, Targetscan, and others, identifying microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) that regulate AKR1B10 expression to explore potential regulatory mechanisms. Elevated AKR1B10 expression was significantly associated with gender, primary tumor size, and fibrosis stage in HCC tissues. High AKR1B10 expression indicated poor prognosis and served as an independent predictor for patient outcomes. Detailed mechanism analysis revealed a positive correlation between high AKR1B10 expression, immune cell infiltration, and pro-inflammatory cytokines, suggesting a potential DANCR-miR-216a-5p-AKR1B10 axis regulating the tumor microenvironment and impacting HCC development and prognosis. The heightened expression of AKR1B10 in HCC is not only related to significant clinical-pathological traits but may also influence HCC progression and prognosis by activating key signaling pathways and altering the tumor immune microenvironment. These findings provide new insights into the role of AKR1B10 in HCC pathogenesis and highlight its potential as a biomarker and therapeutic target.

Hepatocellular carcinoma (HCC), the most common liver cancer, is an important leading cause of death worldwide. Neddylation is a post-translational modification involved in several processes such as cell growth, viability and development. Importantly, the neddylation pathway is upregulated in liver cancer and specifically enriched in patients with poor prognosis. Hu antigen R (HuR), is a RNA-binding protein that stabilizes target mRNAs involved in hepatocyte proliferation, differentiation and malignant transformation. And notably, HuR levels are highly representative in liver and colon cancer. A ground-breaking knowledge about HCC has been to identify that neddylation plays a role in HCC by regulating the liver oncogenic driver HuR. In addition, the neddylation inhibitor MLN4924 has shown antitumoral effects in vitro and in vivo in liver cancer, partly through HuR destabilization. Importantly, high levels of HuR made hepatoma cells more resistant to neddylation inhibition while low levels of HuR sensitized cells to the treatment, suggesting that the levels of HuR determine the druggability of the neddylation pathway in HCC. Overall, our findings highlight the impact that neddylation plays in liver cancer and open a completely new area of research, paving the way for novel therapeutical approaches.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. HCC treatment is hindered by the frequent emergence of chemoresistance to the multikinase inhibitor sorafenib, which has been related to the presence of cancer stem cells (CSCs) that self‐renew and often escape therapy. The key metabolic sensor AMP‐activated kinase (AMPK) has recently been recognized as a tumour growth regulator. In this study, we aimed to elucidate the role of AMPK in the development of a stem cell phenotype in HCC cells. To this end, we enriched the CSC population in HCC cell lines that showed increased expression of drug resistance (ALDH1A1, ABCB1A) and stem cell (CD133, Nanog, Oct4, alpha fetoprotein) markers and demonstrated their stemness phenotype. These cells were refractory to sorafenib‐induced cell death. We report that sorafenib‐resistant cells had lower levels of total and phosphorylated AMPK as well as its downstream substrate, ACC, compared with the parental cells. Interestingly, AMPK knockdown with siRNA or inhibition with dorsomorphin increased the expression of stem cell markers in parental cells and blocked sorafenib‐induced cell death. Conversely, the upregulation of AMPK, either by transfection or by pharmacological activation with A‐769662, decreased the expression of ALDH1A1, ABCB1A, CD133, Nanog, Oct4, and alpha fetoprotein, and restored sensitivity to sorafenib. Analysis of the underlying mechanism points to hypoxia‐inducible factor HIF‐1α as a regulator of stemness. In vivo studies in a xenograft mouse model demonstrated that stem‐like cells have greater tumourigenic capacity. AMPK activation reduced xenograft tumour growth and decreased the expression of stem cell markers. Taken together, these results indicate that AMPK may serve as a novel target to overcome chemoresistance in HCC.

The immunobiology of hepatocellular carcinoma in humans and mice: Basic concepts and therapeutic implications

Objective: Hepatocellular carcinoma (HCC) is a highly lethal cancer with significant mortality, primarily attributed to metastasis. Although Protocadherin Gamma Subfamily A, 9 (PCDHGA9) has been identified as a tumor suppressor gene in cancer metastasis, its role in HCC remains ambiguous. This study clarifies the role of PCDHGA9 in HCC by examining its expression, clinical significance, and molecular activities. Methods: Tissue microarray immunofluorescence analysis evaluated the expression of PCDHGA9 and its clinical relevance. In vitro experiments involved manipulating PCDHGA9 levels in SK-HEP-1 cells to assess migration through wound-healing and transwell assays. In vivo, shPCDHGA9 cell injections were utilized to observe effects on tumor growth and metastasis. Protein analysis and Western Blot validated epithelial-mesenchymal transition (EMT)-related proteins. Subsequent to TGF-β treatment, cell proliferation and apoptosis were quantified using cell counting kit-8 and flow cytometry, respectively, followed by investigation of TGF-β effects on PCDHGA9 N6-methyladenosine (m6A) modification via Methylated RNA immunoprecipitation, RT-qPCR, and Western blot analysis. Results: Downregulation of PCDHGA9 expression in HCC tissues is correlated with poor prognosis. In vitro experiments demonstrated that modulating PCDHGA9 expression influenced HCC cell migration. In vivo, PCDHGA9 knockdown is correlated with increased metastasis. Furthermore, TGF-β stimulation promoted cell proliferation and inhibited apoptosis. Mechanistically, TGF-β-mediated m6A modification led to PCDHGA9 decay, promoting EMT in HCC cells. Conclusion: PCDHGA9 serves as a potential tumor suppressor in HCC by inhibiting EMT. During this process, TGF-β is observed to exert regulatory control over m6A modifications of PCDHGA9.

Background/Aims: Hepatocellular carcinoma (HCC) is a molecularly heterogeneous solid malignancy that carries a dismal prognosis. Tanshinone IIA (Tan-IIA) is involved in the regulation of N6-methyladenosine (m6A) modification and plays an anti-tumor role in HCC, but whether Tan-IIA regulates HCC by mediating m6A modification is unclear.Methods and Materials:Cell apoptosis, invasion, proliferation, viability, and stemness were estimated with flow cytometry, transwell, 5-ethynyl-2’-deoxyuridine, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide, and sphere-forming assays. Methyltransferase-like 14 (METTL14) and 3 (METTL3) mRNA and protein levels were detected with reverse transcription-quantitative polymerase chain reaction and western blotting. Total m6A levels were measured using an m6A RNA methylation quantification kit. A possible regulation of tribbles pseudokinase-3 (TRIB3) expression by METTL3 in an m6A-modified manner was predicted through RM2Target and SRAMP and verified by m6A methylated RNA immunoprecipitation (MeRIP) and RIP. Mouse xenograft models assessed the action of Tan-IIA in HCC tumorigenesis.Results:Tanshinone IIA restrained HCC cell viability, proliferation, invasion, and stemness, and induced HCC cell apoptosis invitro, as well as repressed tumor growth in xenograft models. METTL3 and TRIB3 were upregulated in HCC samples and downregulated in Tan-IIA-treated HCC cells and xenograft tumors. METTL3 facilitated HCC cell viability, proliferation, invasion, and stemness by enhancing TRIB3 mRNA stability through m6A modification. Tan-IIA played its role by downregulating TRIB3, and Tan-IIA mediated TRIB3 expression by METTL3.Conclusion:Tanshinone IIA restrained HCC progression by regulating METTL3-mediated m6A modification of TRIB3 mRNA, offering evidence to support the clinical translation of Tan-IIA.

N6-methyladenosine (m6A) modification is the most common mRNA modification, and it is involved in mRNA stability and translation regulation. However, the roles of m6A modification in the migration and invasion of hepatocellular carcinoma (HCC) are yet to be fully elucidated. Hence, this study aimed to uncover the role of m6A modification in HCC-cell invasion and migration and the therapeutic potential of corosolic acid in HCC treatment. In this study, we found methyltransferase-like 3 (METTL3) to play an oncogenic role in HCC. METTL3 expression and global m6A levels were increased in HCC cell lines and tumour tissues. Importantly, high METTL3-expression levels were associated with poor HCC prognosis. METTL3 overexpression promoted HCC-cell invasion and migration, whereas METTL3 inhibition suppressed it. Mechanistically, METTL3 increased the m6A levels of Snail mRNA, thereby upregulating the mRNA and protein levels of Snail and promoting HCC-cell invasion and migration. Moreover, we found the traditional Chinese medicine corosolic acid (CA) to inhibit HCC-cell migration and invasion by decreasing METTL3 and Snail expression. METTL3 overexpression attenuated the CA-induced inhibition of HCC-cell invasion and migration. Collectively, these findings indicate that CA suppressed METTL3 expression, which inhibited Snail mRNA m6A modification and decreased Snail expression, thus inhibiting the migration and invasion of HCC cells. Therefore, METTL3 is an important therapeutic target in HCC treatment, and CA is a potential therapeutic option for HCC treatment.

Emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) play important roles in tumor metastasis and recurrence. Understanding molecular mechanisms that regulate the EMT process is crucial for improving treatment of hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) play important roles in HCC; however, the mechanisms by which miRNAs target the EMT and their therapeutic potential remains largely unknown. To better explore the roles of miRNAs in the EMT process, we established an EMT model in HCC cells by transforming growth factor beta 1 treatment and found that several tumor-related miRNAs were significantly decreased. Among these miRNAs, miR-125b expression was most strongly suppressed. We also found down-regulation of miR-125b in most HCC cells and clinical specimens, which correlated with cellular differentiation in HCC patients. We then demonstrated that miR-125b overexpression attenuated EMT phenotype in HCC cancer cells, whereas knockdown of miR-125b promoted the EMT phenotype in vitro and in vivo. Moreover, we found that miR-125b attenuated EMT-associated traits, including chemoresistance, migration, and stemness in HCC cells, and negatively correlated with EMT and cancer stem cell (CSC) marker expressions in HCC specimens. miR-125b overexpression could inhibit CSC generation and decrease tumor incidence in the mouse xenograft model. Mechanistically, our data revealed that miR-125b suppressed EMT and EMT-associated traits of HCC cells by targeting small mothers against decapentaplegic (SMAD)2 and 4. Most important, the therapeutic delivery of synthetic miR-125b mimics decreased the target molecule of CSC and inhibited metastasis in the mice model. These findings suggest a potential therapeutic treatment of miR-125b for liver cancer. miR-125b exerts inhibitory effects on EMT and EMT-associated traits in HCC by SMAD2 and 4. Ectopic expression of miR-125b provides a promising strategy to treat HCC.

LncRNA OR3A4 participates in the angiogenesis of hepatocellular carcinoma through modulating AGGF1/akt/mTOR pathway

IGF2BP1/AIFM2 axis regulates ferroptosis and glycolysis to drive hepatocellular carcinoma progression.

B56ε is a regulatory subunit of the serine/threonine protein phosphatase 2A, which is abnormally expressed in tumors and regulates various tumor cell functions. At present, the application of B56ε in pan-cancer lacks a comprehensive analysis, and its role and mechanism in hepatocellular carcinoma (HCC) are still unclear. To analyze B56ε in pan-cancer, and explore its role and mechanism in HCC. The Cancer Genome Atlas, Genotype-Tissue Expression, Gene Expression Profiling Interactive Analysis, and Tumor Immune Estimation Resource databases were used to analyze B56ε expression, prognostic mutations, somatic copy number alterations, and tumor immune characteristics in 33 tumors. The relationships between B56ε expression levels and drug sensitivity, immunotherapy, immune checkpoints, and human leukocyte antigen (HLA)-related genes were further analyzed. Gene Set Enrichment Analysis (GSEA) was performed to reveal the role of B56ε in HCC. The Cell Counting Kit-8, plate cloning, wound healing, and transwell assays were conducted to assess the effects of B56ε interference on the malignant behavior of HCC cells. In most tumors, B56ε expression was upregulated, and high B56ε expression was a risk factor for adrenocortical cancer, HCC, pancreatic adenocarcinoma, and pheochromocytoma and paraganglioma (all P < 0.05). B56ε expression levels were correlated with a variety of immune cells, such as T helper 17 cells, B cells, and macrophages. There was a positive correlation between B56ε expression levels with immune checkpoint genes and HLA-related genes (all P < 0.05). The expression of B56ε was negatively correlated with the sensitivity of most chemotherapy drugs, but a small number showed a positive correlation (all P < 0.05). GSEA analysis showed that B56ε expression was related to the cancer pathway, p53 downstream pathway, and interleukin-mediated signaling in HCC. Knockdown of B56ε expression in HCC cells inhibited the proliferation, migration, and invasion capacity of tumor cells. B56ε is associated with the microenvironment, immune evasion, and immune cell infiltration of multiple tumors. B56ε plays an important role in HCC progression, supporting it as a prognostic marker and potential therapeutic target for HCC.

Background:Noncoding RNAs are crucial regulators acting as either tumor suppressor genes or oncogenes in human cancer progression. The aberrant expression of noncoding RNAs has been confirmed in different kinds of cancers. Hepatocellular carcinoma is one of the most common malignant tumors worldwide, characterized by insidious onset, great malignancy, and high rates of recurrence and metastasis. Due to lack of early predictive markers, numerous patients are diagnosed in the late stages. As therapeutic options for advanced patients are quite limited, great efforts have been made to screen patients at early stages. A previous study reported that small nucleolar RNA host gene 18 played crucial role in glioma. However, its functions and roles in hepatocellular carcinoma are unknown.Purpose:To explore its functional role and diagnostic value in hepatocellular carcinoma, we investigated its expression level.Methods:We performed real-time quantitative polymerase chain reaction in tumor tissues and adjacent noncancerous tissues derived from patients with hepatocellular carcinoma as well as in plasma, including samples from the healthy control, patients with hepatitis B, cirrhosis, and hepatocellular carcinoma.Results:Small nucleolar RNA host gene 18 was downregulated in liver tissues compared to paired adjacent noncancerous tissues (P < .0001). Meanwhile, plasma small nucleolar RNA host gene 18 showed a relatively high sensitivity and specificity (75.61% and 73.49%) for distinguishing patients with hepatocellular carcinoma whose α-fetoprotein levels were below 200 ng/mL from the healthy controls.Conclusion:Our study suggested that small nucleolar RNA host gene 18 might act as a tumor suppressor gene in hepatocellular carcinoma and potentially a diagnostic indicator to distinguish hepatocellular carcinoma from the healthy control and cirrhosis.

Oxidative DNA damage is closely related to the occurrence and progression of cancer. Oxidative stress plays an important role in alcohol-induced hepatocellular carcinoma (HCC). Aldehyde dehydrogenase (ALDH) is a family of enzymes that plays an essential role in the reducing oxidative damage. However, how ALDHs family affects alcohol-related HCC remains obscure. We aimed to explore the correlation between the differential expression of ALDHs in patients with HCC and pathological features, as well as the relationship between ALDHs and prognosis, and finally analyze the possible mechanism of ALDHs in targeted therapy of HCC. The data of HCC were downloaded from The Cancer Genome Atlas (TCGA) database. This research explored the expression and prognostic values of ALDHs in HCC using Oncomine, UALCAN, Human Protein Atlas, cBioPortal, Kaplan–Meier plotter, GeneMANIA, Tumor Immune Estimation Resource, GEPIA databases, and WebGestalt. Low mRNA and protein expressions of ALDHs were found to be significantly associated with tumor grade and clinical cancer stages in HCC patients. In particular, the loss of ALDH expression is more obvious in Asians, and its effect on prognosis is far more significant than that in the White race. Our findings play an important role in the study of prognostic markers and anti-liver cancer therapeutic targets for the members of the ALDHs family, especially in patients with liver cancer in Asia.

BackgroundHepatocellular carcinoma is a fatal malignancy that lacking specific therapies. Homeobox B4 (HOXB4) was negatively correlated with poor prognosis in cancers, but its role in hepatocellular carcinoma has not been elucidated.ResultsWe confirmed that HOXB4 was downregulated in hepatocellular carcinoma tissues and lower HOXB4 expression associated with poor prognosis. Gain- and loss-of function experiments were performed to understand the functional consequences. We revealed that HOXB4 overexpression inhibited proliferation and metastasis of hepatocellular carcinoma cells, accompanied with the decrease in epithelial-mesenchymal transition and increase in cell apoptosis. Database analysis showed that HOXB4 was positively correlated with the immune infiltration. PD-L1 expression was decreased in HOXB4 overexpressed hepatocellular carcinoma cells. HOXB4 overexpression was confirmed to inhibit the progression of hepatocellular carcinoma and promote T cell infiltration in vivo. N6-methyladenosine (m6A) modification was implicated in the tumorigenesis. RNA-seq analysis showed that HOXB4 overexpression modulated METTL7B expression. With the performance of dual-luciferase reporter, ChIP, and DNA pulldown assays, we revealed that HOXB4 binding to METTL7B promoter and inhibited its mRNA expression. The increased aggressiveness of hepatocellular carcinoma cells and the enhanced immune escape, triggered by HOXB4 knockdown, were inhibited via METTL7B downregulation. Methylated RNA immunoprecipitation assay displayed that METTL7B controlled the mRNA decay of TKT in m6A methylation. METTL7B overexpression increase the expression of TKT, ultimately promoting hepatocellular carcinoma progression and immune evasion.ConclusionsHOXB4 mediated the malignant phenotypes and modulated the immune evasion via METTL7B/TKT axis. The HOXB4/METTL7B cascade and its downstream changes might be novel targets for blocking hepatocellular carcinoma progression.Graphical