Function In Hepatocellular Carcinoma Research Articles

Alterations of Krüppel-like Factor Signaling and Potential Targeted Therapy for Hepatocellular Carcinoma.

Krüppel-like factors (KLFs, total 18 members) from the zinc finger protein (ZFP) super-family have a wide range of biological functions in hepatocellular carcinoma (HCC). This paper reviews the recent some progresses of aberrant KLFs with their potential values for diagnosis, prognosis, and targeted therapy in HCC. The recent advances of oncogenic KLFs in the diagnosis, prognosis, and targeted therapy of HCC were reviewed based on the related literature on PUBMED and clinical investigation. Based on the recent literature, KLFs, according to biological functions in HCC, are divided into 4 subgroups: promoting (KLF5, 7, 8, 13), inhibiting (KLF3, 4, 9~12, 14,17), dual (KLF2,6), and unknown functions (KLF1, 15, 16, or 18 ?). HCC-related KLFs regulate downstream gene transcription during hepatocyte malignant transformation, participating in cell proliferation, apoptosis, invasion, and metastasis. Some KLFs have diagnostic or prognostic value, and other KLFs with inhibiting promoting function or over-expressing inhibiting roles might be molecular targets for HCC therapy. These data have suggested that Abnormal expressions of KLFs were associated with HCC progression. Among them, some KLFs have revealed the clinical values of diagnosis or prognosis, and other KLFs with the biological functions of promotion or inhibition might be as effectively molecular targets for HCC therapy.

Overexpression of ZFP69B promotes hepatocellular carcinoma growth by upregulating the expression of TLX1 and TRAPPC9

BackgroundT-cell leukemia homeobox protein 1 (TLX1) has been revealed as a hub transcription factor in leukemia, while its function in hepatocellular carcinoma (HCC) has not been well described. Here, we investigated the regulation and function of TLX1 in HCC.MethodsTLX1 and its possible upstream and downstream molecules in HCC were identified using bioinformatics tools, which were then verified by RT-qPCR assay. CCK-8, wound healing, and Transwell invasion assays were performed to detect the effects of TLX1 knockdown on HCC cells. The interactions between TLX1 and trafficking protein particle complex subunit 9 (TRAPPC9) or Zinc finger protein 69 homolog B (ZFP69B) were further probed by ChIP and luciferase reporter assays. Rescue experiments were finally conducted in vitro and in vivo.ResultsTLX1 was highly expressed in HCC cells, and the knockdown of TLX1 led to reduced malignant biological behavior of HCC cells. TLX1 bound to the promoter region of TRAPPC9, thereby promoting TRAPPC9 expression. Overexpression of TRAPPC9 attenuated the effect of TLX1 reduction on suppressing malignant behavior of HCC cells. ZFP69B was also highly expressed in HCC cells and bound to the promoter region of TLX1 to induce TLX1 expression. Knockdown of ZFP69B inhibited the viability and mobility of HCC cells in vitro and tumor growth in vivo, and overexpression of TLX1 rescued this inhibition.ConclusionThese findings suggest that ZFP69B promotes the proliferation of HCC cells by directly upregulating the expression of TLX1 and the ensuing TRAPPC9.

LAYN Serves as a Prognostic Biomarker and Downregulates Tumor-Infiltrating CD8+ T Cell Function in Hepatocellular Carcinoma.

Layilin (LAYN) represents a valuable prognostic biomarker across various tumor types, while also serving as an innovative indicator of dysfunctional or exhausted CD8+ T cells and exhibiting correlation with immune context. However, the immune function and prognostic significance of LAYN in hepatocellular carcinoma (HCC) remain unexplored. Therefore, our objective is to investigate the role of LAYN in CD8+ T cell exhaustion, clinical prognosis, and the tumor microenvironment within HCC. TIMER or GEPIA databases were used to analyze LAYN expression level and its correlation with immune infiltration in HCC. Bioinformatics analysis was conducted on TCGA and scRNA-seq cohorts. The evaluation of LAYN expression level in fresh specimens was performed through IF, IHC, and ELISA assays. Flow cytometry and mRNA-seq were employed to investigate co-expressed genes of LAYN, the LAYN+CD8+ T cell exhaustion signature and immune function. Cell proliferation ability and killing activity were assessed using CCK8 and CFSE/PI. The expression level of LAYN in HCC tumors was significantly higher compared to peri-tumors. Patients with high levels of LAYN exhibited poorer OS. GO or KEGG analysis confirmed that LAYN was involved in immune response and was positively associated with CD8+ T cell immune infiltration levels. Furthermore, LAYN negatively regulated the immune function of CD8+ T cells, leading to dysfunctional phenotypes characterized by elevated levels of CD39, TIM3 and reduced levels of perforin, TNF-α, Ki-67. CFSE/PI assays demonstrated that LAYN+CD8+ T cells displayed decreased cytotoxic activity. Additionally, there was a positive correlation between LAYN and CD146 levels, which are involved in adhesion and localization processes of CD8+ T cells. Interestingly, blocking LAYN partially restored the exhaustion properties of CD8+ T cells. LAYN exhibits a strong correlation with immune infiltration in the TME and represents a novel biomarker for predicting clinical prognosis in HCC. Moreover, targeting LAYN may hold promise as an effective strategy for HCC immunotherapy.

Comprehensive prognostic and immunological analysis of Cullin2 in pan-cancer and its identification in hepatocellular carcinoma.

As a member of the Cullin family, Cullin2 (CUL2) is involved in the development and spread of different types of cancers. However, the precise role of CUL2 in human cancer remains largely elusive. In this study, various databases were applied to observe the CUL2 expression. Kaplan-Meier and Spearman correlation analyses were employed to investigate the potential links between CUL2 level, patient prognosis, and the infiltration of immune cells. In addition, the association between CUL2 and the efficacy of immunotherapy in an immunotherapy cohort was investigated. Moreover, the expression and distribution of CUL2 in cells were observed using the Human Protein Atlas (THPA) database. Finally, clinical tissue specimens and in vitro function assays were conducted to validate the expressions and effects of CUL2 on the biological functions in hepatocellular carcinoma (HCC) cells. While there are variations in CUL2 expression across different organs and cell types, it is notably upregulated in a majority of tumor tissues. In addition, CUL2 gene mutations are common in multiple cancers with low mutation rates and CUL2 is closely related to the prognosis of some cancer's patients, some immune regulatory factors, TMB, MSI, MMR genes, and DNA methylation. Further, our results found that downregulating CUL2 inhibits the proliferation, and migration abilities. The expression of CUL2 has an impact on the prognosis of various tumors, and this correlation is particularly noteworthy due to its significant association with the infiltration of immune cells within tumors. CUL2 was an oncogene contributing to the progression of HCC.

TRIM29 modulates proteins involved in PTEN/AKT/mTOR and JAK2/STAT3 signaling pathway and suppresses the progression of hepatocellular carcinoma.

Tripartite motif-containing 29 (TRIM29), also known as the ataxia telangiectasia group D-complementing (ATDC) gene, has been reported to play an oncogenic or tumor suppressive role in developing different tumors. So far, its expression and biological functions in hepatocellular carcinoma (HCC) remain unclear. We investigated TRIM29 expression pattern in human HCC samples using quantitative RT-PCR and immunohistochemistry. Relationships between TRIM29 expression level, clinical prognostic indicators, overall survival (OS), and disease-free survival (DFS) were evaluated by Kaplan-Meier analysis and Cox proportional hazards model. A series of in vitro experiments and a xenograft tumor model were conducted to detect the functions of TRIM29 in HCC cells. RNA sequencing, western blotting, and immunochemical staining were performed to assess the molecular regulation of TRIM29 in HCC. We found that the mRNA and protein levels of TRIM29 were significantly reduced in HCC samples, compared with adjacent noncancerous tissues, and were negatively correlated with poor differentiation of HCC tissues. Survival analysis confirmed that lower TRIM29 expression significantly correlated with shorter OS and DFS of HCC patients. TRIM29 overexpression remarkably inhibited cell proliferation, migration, and EMT in HCC cells, whereas knockdown of TRIM29 reversed these effects. Moreover, deactivation of the PTEN/AKT/mTOR and JAK2/STAT3 pathways might be involved in the tumor suppressive role of TRIM29 in HCC. Our findings indicate that TRIM29 in HCC exerts its tumor suppressive effects through inhibition of the PTEN/AKT/mTOR and JAK2/STAT3 signaling pathways and may be used as a potential biomarker for survival in patients with HCC.

CDKL3 is a promising biomarker for diagnosis and prognosis prediction in patients with hepatocellular carcinoma.

Cyclin-dependent kinase-like 3 (CDKL3) has been identified as an oncogene in certain types of tumors. Nonetheless, its function in hepatocellular carcinoma (HCC) is poorly understood. In this study, we conducted a comprehensive analysis of CDKL3 based on data from the HCC cohort of The Cancer Genome Atlas (TCGA). Our analysis included gene expression, diagnosis, prognosis, functional enrichment, tumor microenvironment and metabolic characteristics, tumor burden, mRNA expression-based stemness, alternative splicing, and prediction of therapy response. Additionally, we performed a cell counting kit-8 assay, TdT-mediated dUTP nick-end Labeling staining, migration assay, wound healing assay, colony formation assay, and nude mouse experiments to confirm the functional relevance of CDKL3 in HCC. Our findings showed that CDKL3 was significantly upregulated in HCC patients compared to controls. Various bioinformatic analyses suggested that CDKL3 could serve as a potential marker for HCC diagnosis and prognosis. Furthermore, CDKL3 was found to be involved in various mechanisms linked to the development of HCC, including copy number variation, tumor burden, genomic heterogeneity, cancer stemness, and alternative splicing of CDKL3. Notably, CDKL3 was also closely correlated with tumor immune cell infiltration and the expression of immune checkpoint markers. Additionally, CDKL3 was shown to independently function as a risk predictor for overall survival in HCC patients by multivariate Cox regression analysis. Furthermore, the knockdown of CDKL3 significantly inhibited cell proliferation in vitro and in vivo, indicating its role as an oncogene in HCC. Taken together, our findings suggest that CDKL3 shows promise as a biomarker for the detection and treatment outcome prediction of HCC patients.

Albumin-bilirubin score in non-malignant liver diseases should be properly validated.

The albumin-bilirubin (ALBI) score to assess the risk of decompensation in patients with initially compensated cirrhosis may improve their prognostic evaluation. This letter critically evaluates the research, which utilizes the ALBI score to forecast decompensation in cirrhosis patients over a three-year period. This score was initially developed to assess liver function in hepatocellular carcinoma, its prognostic utility for non-malignant liver diseases has now been explored, recognizing decompensation as a pivotal event that significantly affects patient's survival. Some concerns regarding the methodology of this research may be raised, particularly the exclusive use of radiological diagnosis, potentially including patients without definite cirrhosis and thus skewing the decompensation risk assessment. The reported predominance of variceal bleeding as a decompensating event conflicts with established literature, that often reports ascites as the initial decompensation manifestation. The letter highlights the absence of details on esophageal varices and their management, which could introduce bias in evaluating the ALBI score's predictive power. Furthermore, the letter points out the small sample size of patients with high-risk ALBI grades, potentially compromising the score's validity in this context. We suggest prospective future research to investigate the dynamic changes in the ALBI score over time to reinforce the validity of the ALBI score as a predictor of decompensation in non-malignant liver disease.

Heat shock protein HSPA13 promotes hepatocellular carcinoma progression by stabilizing TANK

HSPA13, an important member of the heat shock protein family, plays an essential role in the oncogenesis of many organs, but the mechanism and function in hepatocellular carcinoma (HCC) is still unclear. In the present study, we found that HSPA13 was highly expressed in HCC and predicted poor clinical prognosis. Upregulation of HSPA13 was significantly associated with vascular invasion in HCC patients. Functionally, knockdown experiments demonstrated that HSPA13 promoted HCC proliferation, migration, and invasion. Mechanistic investigation showed that HSPA13 could interact with TANK to inhibit its ubiquitination and degradation. In addition, the expression of HSPA13 and TANK were positively correlated in HCC tissues. To conclude, the present study uncovers the oncogenic function of HSPA13 in the progression of HCC by regulating the stability of TANK. These findings suggest that HSPA13 and TANK may serve as promising targets for the diagnosis and treatment of HCC.

Effect of RPL27 knockdown on the proliferation and apoptosis of human liver cancer cells

RPL27 is linked to the development of various diseases including malignant tumors. RPL27 may play an oncogenic function in hepatocellular carcinoma (HCC), but this is unknown. So, the aim of this study was to investigate how the human liver cancer cell lines SNU449 and HepG2 responded to RPL27 knockdown in terms of proliferation and apoptosis. SNU449 and HepG2 were cultured and infected with shCon and shRPL27 lentiviral particles to induce RPL27 knockdown, and then RPL27 expression was detected using qPCR and Western blot. Cell proliferation was measured using CCK8, cell cloning, cell scraping, and transwell migration and invasion, while apoptosis was measured using flow cytometry (FCM). The qPCR revealed that mRNA expression of RPL27 decreased after knocking down RPL27 in cells. The CCK8 and cell cloning assay confirmed that knocking down RPL27 significantly reduced cell viability. The cell scratch assay and transwell assays showed that the proliferation rate decreased after knocking down RPL27. A substantial increase in apoptotic cells was discovered by FCM. According to WB, RPL27 knockdown increased the expression of Bax and Caspase-3 while decreasing the expression of bcl-2. The findings showed that RPL27 knockdown inhibited cell proliferation in SNU449 and HepG2 via inducing apoptosis, proving that RPL27 is a novel gene linked with HCC and is crucial for both proliferation and apoptosis. These outcomes imply that RPL27 may be a potential target for liver cancer diagnosis and therapy.

TRIM55 Promotes Proliferation of Hepatocellular Carcinoma Through Stabilizing TRIP6 to Activate Wnt/β-Catenin Signaling.

Tripartite motif containing 55 (TRIM55) is a member of the TRIM family and functions as an E3 ubiquitin ligase. It acts as a cancer promoter or suppressor in the malignant processes of multiple cancers. However, its proliferative function in hepatocellular carcinoma (HCC) has been poorly studied, and its underlying molecular mechanism remains unclear. In the present study, we investigated the role of TRIM55 in HCC and its mechanism of promoting HCC proliferation. Protein expression levels of TRIM55 were measured in paired HCC and normal tissue samples using immunohistochemical (IHC) staining. The correlation between TRIM55 and clinical features was evaluated by statistical analysis. At the same time, overexpression and knockdown experiments, cycloheximide (CHX) interference experiments, ubiquitination, co-immunoprecipitation and immunofluorescence staining experiments, as well as animal experiments were used to evaluate the potential mechanism that TRIM55 promotes proliferation of hepatocellular carcinoma in vitro and in vivo. TRIM55 expression in HCC specimens was higher compared with the corresponding non-tumor tissues. The overall survival and disease-free survival time of patients with high TRIM55 expression were shorter than those with low expression of TRIM55. Functionally, TRIM55 promoted the proliferation of HCC cells and accelerated the growth of HCC xenografts. Mechanistically, TRIM55 interacted with thyroid receptor interacting protein 6 (TRIP6) and regulate its stability by influencing the ubiquitination process, thereby affecting the Wnt signaling pathway. Our results indicate that TRIM55 promotes HCC proliferation by activating Wnt signaling pathways by stabilizing TRIP6. Therefore, targeting TRIM55 may be an effective therapeutic strategy to inhibit HCC growth.

Characterization of disease-associated microbiota in hepatocellular carcinoma.

This study aimed to investigate the differences in the composition of microbial communities and related functions in hepatocellular carcinoma (HCC) tumours and matched normal tissues were investigated. Tumour tissues and matched normal samples were collected from 30 HCC patients. Genomic DNA was collected and subjected to sequencing of the V3 + V4 region of the 16S rRNA gene. The microbial community profiles and metabolic pathway predictions of the different groups were characterized and compared. Tumour and adjacent tissues had similar microbiota compositions but differed in abundance. Proteobacteria and Firmicutes abundance decreased and Cyanobacteria and Acidobacteria abundance increased in the tumour tissue. The microbial community diversity was higher in the tumour tissues than in adjacent samples, with potentially more dominant taxa in the adjacent tissues, including Firmicutes, Proteobacteria, and Actinobacteria. Acidobacteria, Cyanobacteria, and Chloroflexi were the dominant microbes in tumour tissues. A total of 46 metabolic pathways were identified. Global and overview maps were the most abundant pathways, followed by carbohydrate metabolism, energy metabolism, metabolism of cofactors and vitamins, and membrane transport. The top 50 most highly correlated microbial genera included Klebsiella, Rhodococcus, Ochrobactrum, and Azoarcus. Fonticella, Haloimpatiens, Brevibacterium, and Acidothermus were positively correlated with other microbial genera. The microbiota of adjacent tissues was more robust in the network analysis. This study revealed differences in microbial composition between HCC tumour tissues and normal tissues and differences in microbial abundance associated with different metabolic functions. Cyanobacteria, Proteobacteria, and Actinobacteria may play important roles in HCC.

RNF2 inhibits E-Cadherin transcription to promote hepatocellular carcinoma metastasis via inducing histone mono-ubiquitination

RNF2 is a RING domain-containing E3 ubiquitin ligase that mediate histone H2A mono-ubiquitination to repress gene transcription, but its expression patterns and molecular function in hepatocellular carcinoma (HCC) remain unclear. Herein, we extracted data from TGCA database and validated RNF2 expression in our own cohort, which revealed that RNF2 was highly expressed in HCC and was associated with malignant characteristics and poor prognosis of HCC. Moreover, RNF2 was demonstrated to promote HCC metastasis via enhancing epithelial-mesenchymal transition (EMT) both in vitro and in vivo. Mechanistically, RNF2 repressed E-Cadherin transcription by increasing the deposition of H2K119ub at the E-Cadherin promoter region. In addition, RNF2-regulated crosstalk between H2AK119ub, H3K27me3 and H3K4me3 synergistically reduced E-Cadherin transcription, which promoted EMT and HCC metastasis. These results indicate that RNF2 played an oncogenic role in HCC progression via inducing EMT, and RNF2 could be a potential therapeutic target for HCC.

PPDPF suppresses the development of hepatocellular carcinoma through TRIM21-mediated ubiquitination of RIPK1

Pancreatic progenitor cell differentiation and proliferation factor (PPDPF) has been reported to play a role in tumorigenesis. However, its function in hepatocellular carcinoma (HCC) remains poorly understood. In this study, we report that PPDPF is significantly downregulated in HCC and the decreased PPDPF expression indicates poor prognosis. In the dimethylnitrosamine (DEN)-induced HCC mouse model, hepatocyte-specific depletion of Ppdpf promotes hepatocarcinogenesis, and reintroduction of PPDPF into liver-specific Ppdpf knockout (LKO) mice inhibits the accelerated HCC development. Mechanistic study shows that PPDPF regulates nuclear factor κB (NF-κB) signaling through modulation of RIPK1 ubiquitination. PPDPF interacts with RIPK1 and facilitates K63-linked ubiquitination of RIPK1 via recruiting the E3 ligase TRIM21, which catalyzes K63-linked ubiquitination of RIPK1 at K140. In addition, liver-specific overexpression of PPDPF activates NF-κB signaling and attenuates apoptosis and compensatory proliferation in mice, which significantly suppresses HCC development. This work identifies PPDPF as a regulator of NF-κB signaling and provides a potential therapeutic candidate for HCC.

5'-tiRNA-Gln inhibits hepatocellular carcinoma progression by repressing translation through the interaction with eukaryotic initiation factor 4A-I.

tRNA-derived small RNAs (tsRNAs) are novel non-coding RNAs that are involved in the occurrence and progression of diverse diseases. However, their exact presence and function in hepatocellular carcinoma (HCC) remain unclear. Here, differentially expressed tsRNAs in HCC were profiled. A novel tsRNA, tRNAGln-TTG derived 5'-tiRNA-Gln, is significantly downregulated, and its expression level is correlated with progression in patients. In HCC cells, 5'-tiRNA-Gln overexpression impaired the proliferation, migration, and invasion in vitro and in vivo, while 5'-tiRNA-Gln knockdown yielded opposite results. 5'-tiRNA-Gln exerted its function by binding eukaryotic initiation factor 4A-I (EIF4A1), which unwinds complex RNA secondary structures during translation initiation, causing the partial inhibition of translation. The suppressed downregulated proteins include ARAF, MEK1/2 and STAT3, causing the impaired signaling pathway related to HCC progression. Furthermore, based on the construction of a mutant 5'-tiRNA-Gln, the sequence of forming intramolecular G-quadruplex structure is crucial for 5'-tiRNA-Gln to strongly bind EIF4A1 and repress translation. Clinically, 5'-tiRNA-Gln expression level is negatively correlated with ARAF, MEK1/2, and STAT3 in HCC tissues. Collectively, these findings reveal that 5'-tiRJNA-Gln interacts with EIF4A1 to reduce related mRNA binding through the intramolecular G-quadruplex structure, and this process partially inhibits translation and HCC progression.

Decreased DIO3OS Expression Predicts Poor Prognosis in Hepatocellular Carcinoma and is Associated with Immune Infiltration.

Hepatocellular carcinoma has become one of the most shared cancers in the whole world because of its high morbidity, poor survival rate, and low recovery rate. LncRNA DIO3 opposite strand upstream RNA (DIO3OS) has been reported to be obviously important in several human cancers, while its biological function in hepatocellular carcinoma (HCC) remains unclear. Here, DIO3OS gene expression data and clinical information of HCC patients were extracted from the Cancer Genome Atlas (TCGA) database and the university of California Santa Cruz (UCSC) Xena database. In our study, the Wilcoxon rank sum test was used to compare DIO3OS expression between healthy individuals and HCC patients. It was found that patients with HCC had significantly lower DIO3OS expression than healthy individuals. Furthermore, Kaplan-Meier curves and Cox regression analysis showed that high DIO3OS expression tended to predict better prognosis and higher survival rate in HCC patients. In addition, the gene set enrichment analysis (GSEA) assay was used to annotate the biological function of DIO3OS. It was found that DIO3OS was significantly correlated with immune invasion in HCC. This was also aided by the subsequent ESTIMATE assay. Our study provides a novel biomarker and therapeutic strategy for patients with hepatocellular carcinoma.

Sex Differences in the Impact of Metabolic Dysfunction-associated Fatty Liver Disease on the of Patients with Hepatocellular Carcinoma After Radical Resection.

Background: International experts have put forward a new definition for metabolic dysfunction-associated fatty liver disease (MAFLD). Nonetheless, sex differences in MAFLD function in hepatocellular carcinoma (HCC) survival is still unknown. Therefore, the current work focused on exploring the gender-specific association of MAFLD effect on prognosis after radical resection of liver cancer. Methods: The long-term prognostic outcomes of 642 HCC patients undergoing hepatectomy were analyzed retrospectively. To calculate overall survival (OS) and recurrence-free survival (RFS), Kaplan-Meier (KM) curve was plotted. Further, using Cox proportional model to explore the prognostic factors. Sensitivity analysis was performed using propensity score matching (PSM) to balance the confounding bias. Results: For MAFLD patients, median OS and RFS times were 6.8 years and 6.1 years, respectively, compared to 8.5 years and 2.9 years in non-MAFLD patients. KM curve shown that compare with non-MAFLD patients, MAFLD patients had a higher survival rate in men, but had a lower survival rate in women (P<0.05). Multivariate analysis showed that MAFLD was significantly risk factor with mortality in the female (HR = 5.177, 95%CI: 1.475-18.193). However, MAFLD was not related to RFS This correlation was consistent after PSM analysis. Conclusions: MAFLD can improve the mortality of women undergoing radical resection for liver cancer, which independently estimate disease prognosis but is not related to recurrence-free survival.

Delineation of a SMARCA4-specific competing endogenous RNA network and its function in hepatocellular carcinoma.

BACKGROUNDHepatocellular carcinoma (HCC) is a common malignancy worldwide, and the mortality rate continues to rise each year. SMARCA4 expression has been associated with poor prognosis in various types of cancer; however, the specific mechanism of action of SMARCA4 in HCC needs to be fully elucidated. AIMTo explore the specific mechanism of action of SMARCA4 in HCC.METHODSHerein, the expression level of SMARCA4 as well as its association with HCC prognosis were evaluated using transcriptome profiling and clinical data of 18 different types of cancer collected from The Cancer Genome Atlas database. Furthermore, SMARCA4-high and -low groups were identified. Thereafter, gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to identify the function of SMARCA4, followed by construction of a SMARCA4-specific competing endogenous RNA (ceRNA) network using starBase database. The role of SMARCA4 in immunotherapy and its association with immune cells were assessed using correlation analysis.RESULTSIt was observed that SMARCA4 was overexpressed and negatively correlated with prognosis in HCC. Further, SMARCA4 expression was positively associated with tumor mutational burden, microsatellite stability, and immunotherapy efficacy. The SNHG3/THUMP3-AS1-miR-139-5p-SMARCA4 ceRNA network was established and could be assumed to serve as a stimulatory mechanism in HCC.CONCLUSIONThe findings of this study demonstrated that SMARCA4 plays a significant role in progression and immune infiltration in HCC. Moreover, a ceRNA network was detected, which was found to be correlated with poor prognosis in HCC. The findings of this study could contribute towards the identification of predictive markers for immunotherapy and a novel mechanism of action for HCC treatment.

NSUN2-mediated mRNA m5C Modification Regulates the Progression of Hepatocellular Carcinoma

RNA modifications affect many biological processes and physiological diseases. The 5-methylcytosine (m5C) modification regulates the progression of multiple tumors. However, its characteristics and functions in hepatocellular carcinoma (HCC) remain largely unknown. Here, we found that HCC tissues had a higher m5C methylation level than the adjacent normal tissues. Transcriptome analysis revealed that the hypermethylated genes mainly participated in the phosphokinase signaling pathways, such as the Ras and PI3K-Akt pathways. The m5C methyltransferase NSUN2 was highly expressed in HCC tissues. Interestingly, the expression of many genes was positively correlated with the expression of NSUN2, including GRB2, RNF115, AATF, ADAM15, RTN3, and HDGF. Real-time PCR assays further revealed that the expression of the mRNAs of GRB2, RNF115, and AATF decreased significantly with the down-regulation of NSUN2 expression in HCC cells. Furthermore, NSUN2 could regulate the cellular sensitivity of HCC cells to sorafenib via modulating the Ras signaling pathway. Moreover, knocking down NSUN2 caused cell cycle arrest. Taken together, our study demonstrates the vital role of NSUN2 in the progression of HCC.

Expression and prognostic signatures of m6A-related lncRNAs in hepatocellular carcinoma.

N6-methyladenosine (m6A) is a common modification and plays an important role in various biological processes, but m6A-related lncRNA functions in hepatocellular carcinoma (HCC) have not been systematically clarified. The clinical data and RNA-seq transcriptome of 375 cases of HCC and 50 cases of normal tissues were obtained from the Cancer Gene Atlas database. Co-expression analysis was used to obtain m6A-related lncRNA. The independent prognostic factors were identified by univariate and multivariate Cox regression models. Kaplan-Meier method was used in survival analysis. The core gene of the mRNA-mRNA interaction network is related to m6A-related lncRNAs obtained by the CytoHubba plugin of Cytoscape. Gene ontology and Kyoto Gene Encyclopedia were analyzed to find out the potential mechanism. CIBERSORT algorithm was used to calculate the relative proportion of immune infiltrating cells. We identified two subgroups (cluster 1 and cluster 2) according to the expression level. The survival analysis curve and receiver operating characteristic curve proved that this model could predict the prognosis of HCC patients. The univariate and multivariate Cox regression analyses showed the independent prognostic value. UBE2C was screened as the pivotal gene. The expression level of m6A-related lncRNAs causes changes in the tumor immune microenvironment. The expression levels of m6A-related lncRNAs were significantly different and the prognostic value of m6A-related lncRNAs was confirmed. The m6A-related lncRNAs are expected to be prognostic signatures in HCC.

MiR-129-5p exerts Wnt signaling-dependent tumor-suppressive functions in hepatocellular carcinoma by directly targeting hepatoma-derived growth factor HDGF

BackgroundIn hepatocellular carcinoma (HCC), histone deacetylases (HDACs) are frequently overexpressed. This results in chromatin compaction and silencing of tumor-relevant genes and microRNAs. Modulation of microRNA expression is a potential treatment option for HCC. Therefore, we aimed to characterize the epigenetically regulated miR-129-5p regarding its functional effects and target genes to understand its relevance for HCC tumorigenesis.MethodsGlobal miRNA expression of HCC cell lines (HLE, HLF, Huh7, HepG2, Hep3B) and normal liver cell lines (THLE-2, THLE-3) was analyzed after HDAC inhibition by miRNA sequencing. An in vivo xenograft mouse model and in vitro assays were used to investigate tumor-relevant functional effects following miR-129-5p transfection of HCC cells. To validate hepatoma-derived growth factor (HDGF) as a direct target gene of miR-129-5p, luciferase reporter assays were performed. Survival data and HDGF expression were analyzed in public HCC datasets. After siRNA-mediated knockdown of HDGF, its cancer-related functions were examined.ResultsHDAC inhibition induced the expression of miR-129-5p. Transfection of miR-129-5p increased the apoptosis of HCC cells, decreased proliferation, migration and ERK signaling in vitro and inhibited tumor growth in vivo. Direct binding of miR-129-5p to the 3′UTR of HDGF via a noncanonical binding site was validated by luciferase reporter assays. HDGF knockdown reduced cell viability and migration and increased apoptosis in Wnt-inactive HCC cells. These in vitro results were in line with the analysis of public HCC datasets showing that HDGF overexpression correlated with a worse survival prognosis, primarily in Wnt-inactive HCCs.ConclusionsThis study provides detailed insights into the regulatory network of the tumor-suppressive, epigenetically regulated miR-129-5p in HCC. Our results reveal for the first time that the therapeutic application of mir-129-5p may have significant implications for the personalized treatment of patients with Wnt-inactive, advanced HCC by directly regulating HDGF. Therefore, miR-129-5p is a promising candidate for a microRNA replacement therapy to prevent HCC progression and tumor metastasis.