The Epigenetic Regulation of HCC Metastasis

RNA-binding protein Trx regulates alternative splicing and promotes metastasis of HCC via interacting with LINC00152

BACKGROUND

Epithelial-mesenchymal transition (EMT) is central to HCC metastasis, in which RNA-binding proteins (RBPs) play a key role.

METHODS

To explore the role of RBPs in metastasis of hepatocellular carcinoma (HCC), whole transcriptome sequencing was conducted to identify differential RBPs between HCC with metastasis and HCC without metastasis. The influence of RBPs on metastasis of HCC was verified by in vitro and in vivo experiments. The interaction of RBPs with non-coding RNAs was evaluated by RNA immunoprecipitation and pull-down assays. RNA sequencing, whole-genome sequencing, and alternative splicing analysis were further performed to clarify post-transcriptional regulation mechanisms.

RESULTS

Whole transcriptome sequencing results showed that expression of thioredoxin (Trx) was significantly upregulated in HCC patients with metastasis. Trx was also found to be associated with poor prognosis in HCC patients. Overexpression of Trx could promote migration and invasion of HCC cells in vitro and increase the rate of lung metastasis of HCC cells in vivo. Moreover, binding assays showed that Trx could bind to LINC00152. As a result, LINC00152 was verified to determine the pro-metastasis function of Trx by knockdown assay. Furthermore, we revealed that Trx could regulate metastasis-associated alternative splicing program. Specifically, angiopoietin 1 (ANGPT1) was the splicing target; the splicing isoform switching of ANGPT1 could activate the PI3K-Akt pathway, upregulate EMT-associated proteins, and promote migration and invasion of HCC cells.

CONCLUSIONS

We found that Trx could interact with LINC00152 and promote HCC metastasis via regulating alternative splicing, indicating that Trx may serve as a novel therapeutic target for HCC treatment.

The Biological Clock of Liver Metabolism in Metabolic Dysfunction-Associated Steatohepatitis Progression to Hepatocellular Carcinoma

Circadian rhythms are endogenous behavioral or physiological cycles that are driven by a daily biological clock that persists in the absence of geophysical or environmental temporal cues. Circadian rhythm-related genes code for clock proteins that rise and fall in rhythmic patterns driving biochemical signals of biological processes from metabolism to physiology and behavior. Clock proteins have a pivotal role in liver metabolism and homeostasis, and their disturbances are implicated in various liver disease processes. Encoded genes play critical roles in the initiation and progression of metabolic dysfunction-associated steatohepatitis (MASH) to hepatocellular carcinoma (HCC) and their proteins may become diagnostic markers as well as therapeutic targets. Understanding molecular and metabolic mechanisms underlying circadian rhythms will aid in therapeutic interventions and may have broader clinical applications. The present review provides an overview of the role of the liver's circadian rhythm in metabolic processes in health and disease, emphasizing MASH progression and the oncogenic associations that lead to HCC.

MiR-519e-5p regulates malignant phenotype of breast cancer cells through binding to CTPS1

MiR-519e-5p and CTPS1 are aberrantly expressed in breast cancer (BC). However, the molecular mechanisms underlying tumorigenesis and development are unknown, and their potential as therapeutic targets needs to be explored. The molecular biology was explored through in vitro cellular experiments, tumor xenograft assay, and analysis of gene expression in human tissue and serum samples. We found that miR-519e-5p expression was much lower and CTPS1 expression was much higher in BC tissues and cells than in the normal tissues and cells. BC cells overexpressing miR-519e-5p or CTPS1 knockdown demonstrated decreased proliferation, migration, and invasion, whereas miR-519e-5p knockdown had the opposite effect. Further studies showed that there is a binding site between miR-519e-5p and CTPS1, leading to their interaction, CTPS1 overexpression and could partially reverse the inhibitory effects of miR-519e-5p overexpression on cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). CTPS1 serum levels were higher in patients with BC, and these levels were associated with some highly correlated clinical indicators, including age, HER-2 index, and T and N staging. Overall, miR-519e-5p slows the proliferation, invasion, migration, and EMT of BC by binding to CTPS1. This study offers a new direction for BC treatment.

Epigenetic Modifiers in Cancer Metastasis

Metastasis is the primary cause of cancer-related death, with the dissemination and colonization of primary tumor cells at the metastatic site facilitated by various molecules and complex pathways. Understanding the biological mechanisms underlying the metastatic process is critical for the development of effective interventions. Several epigenetic modifications have been identified that play critical roles in regulating cancer metastasis. This review aims to provide a comprehensive summary of recent advances in understanding the role of epigenetic modifiers, including histone modifications, DNA methylation, non-coding RNAs, enhancer reprogramming, chromatin accessibility, and N6-methyladenosine, in metastasis-associated processes, such as epithelial-mesenchymal transition (EMT), cancer cell migration, and invasion. In particular, this review provides a detailed and in-depth description of the role of crosstalk between epigenetic regulators in tumor metastasis. Additionally, we explored the potential and limitations of epigenetics-related target molecules in the diagnosis, treatment, and prognosis of cancer metastasis.

A m6A regulators-related classifier for prognosis and tumor microenvironment characterization in hepatocellular carcinoma

Background

Increasing evidence have highlighted the biological significance of mRNA N6-methyladenosine (m6A) modification in regulating tumorigenicity and progression. However, the potential roles of m6A regulators in tumor microenvironment (TME) formation and immune cell infiltration in liver hepatocellular carcinoma (LIHC or HCC) requires further clarification.

Method

RNA sequencing data were obtained from TCGA-LIHC databases and ICGC-LIRI-JP databases. Consensus clustering algorithm was used to identify m6A regulators cluster subtypes. Weighted gene co-expression network analysis (WGCNA), LASSO regression, Random Forest (RF), and Support Vector Machine-Recursive Feature Elimination (SVM-RFE) were applied to identify candidate biomarkers, and then a m6Arisk score model was constructed. The correlations of m6Arisk score with immunological characteristics (immunomodulators, cancer immunity cycles, tumor-infiltrating immune cells (TIICs), and immune checkpoints) were systematically evaluated. The effective performance of nomogram was evaluated using concordance index (C-index), calibration plots, decision curve analysis (DCA), and receiver operating characteristic curve (ROC).

Results

Two distinct m6A modification patterns were identified based on 23 m6A regulators, which were correlated with different clinical outcomes and biological functions. Based on the constructed m6Arisk score model, HCC patients can be divided into two distinct risk score subgroups. Further analysis indicated that the m6Arisk score showed excellent prognostic performance. Patients with a high m6Arisk score was significantly associated with poorer clinical outcome, lower drug sensitivity, and higher immune infiltration. Moreover, we developed a nomogram model by incorporating the m6Arisk score and clinicopathological features. The application of the m6Arisk score for the prognostic stratification of HCC has good clinical applicability and clinical net benefit.

Conclusion

Our findings reveal the crucial role of m6A modification patterns for predicting HCC TME status and prognosis, and highlight the good clinical applicability and net benefit of m6Arisk score in terms of prognosis, immunophenotype, and drug therapy in HCC patients.

Hepatitis B Virus Infection: A Mini Review

Hepatitis B and C viruses (HBV and HCV) are the leading causes of end-stage liver disease worldwide. Although there is a potent vaccine against HBV, many new infections are recorded annually, especially in poorly resourced places which have lax vaccination policies. Again, as HBV has no cure and chronic infection is lifelong, vaccines cannot help those already infected. Studies to thoroughly understand the HBV biology and pathogenesis are limited, leaving much yet to be understood about the genomic features and their role in establishing and maintaining infection. The current knowledge of the impact on disease progression and response to treatment, especially in hyperendemic regions, is inadequate. This calls for in-depth studies on viral biology, mainly for the purposes of coming up with better management strategies for infected people and more effective preventative measures for others. This information could also point us in the direction of a cure. Here, we discuss the progress made in understanding the genomic basis of viral activities leading to the complex interplay of the virus and the host, which determines the outcome of HBV infection as well as the impact of coinfections.

Integrated Exploration of Epigenetic Dysregulation Reveals a Stemness/EMT Subtype and MMP12 Linked to the Progression and Prognosis in Hepatocellular Carcinoma

Epigenetic dysregulation drives aberrant transcriptional programs playing a critical role in hepatocellular carcinoma (HCC), which may provide novel insights into the heterogeneity of HCC. This study performed an integrated exploration on the epigenetic dysregulation of miRNA and methylation. We discovered and validated three patterns endowed with gene-related transcriptional traits and clinical outcomes. Specially, a stemness/epithelial-mesenchymal transition (EMT) subtype was featured by immune exhaustion and the worst prognosis. Besides, MMP12, a characteristic gene, was highly expressed in the stemness/EMT subtype, which was verified as a pivotal regulator linked to the unfavorable prognosis and further proven to promote tumor proliferation, invasion, and metastasis in vitro experiments. Proteomic analysis by mass spectrometry sequencing also indicated that the overexpression of MMP12 was significantly associated with cell proliferation and adhesion. Taken together, this study unveils innovative insights into epigenetic dysregulation and identifies a stemness/EMT subtype-specific gene, MMP12, correlated with the progression and prognosis of HCC.

Exploring the role of CDCA4 in liver hepatocellular carcinoma using bioinformatics analysis and experiments

Liver hepatocellular carcinoma (LIHC) encompasses diverse therapeutic approaches, among which targeted therapy has gained significant prominence in recent years. The identification of numerous targets and the increasing clinical application of targeted drugs have greatly improved LIHC treatment. However, the precise role of CDCA4 (Cell Division Cycle Associated 4), as well as its underlying mechanisms and prognostic implications in LIHC, remains unclear. CDCA4 expression levels in LIHC were analyzed using multiple databases including the cancer genome atlas (TCGA), gene expression profiling interactive analysis (GEPIA), and ULCAN, as well as the datasets E_TABM_36, GSE144269, GSE14520, and GSE54236. The prognostic value of CDCA4 was then evaluated. Subsequently, the association between CDCA4 and immune cells was investigated. Enrichment analysis (GSEA) was utilized to investigate the functional roles and pathways linked to CDCA4. Additionally, the methylation patterns and drug sensitivity of CDCA4 were examined. A predictive model incorporating immune genes related to CDCA4 was developed. The TISCH dataset was used to investigate the single-cell expression patterns of CDCA4. Finally, validation of CDCA4 expression levels was conducted through RT-PCR, Western blotting, and immunohistochemistry. CDCA4 exhibited significant overexpression in LIHC and demonstrated significant correlations with clinical features. High expression of CDCA4 is associated with a poorer prognosis. Analysis of immune infiltration and enrichment revealed its association with the immune microenvironment. Furthermore, its expression is correlated with methylation and mutation patterns. CDCA4 is associated with 19 drugs. Prognostic models utilizing CDCA4 demonstrate favorable effectiveness. T cell subtypes were found to be associated with CDCA4 through single-cell analysis. The conclusive experiment provided evidence of significant upregulation of CDCA4 in LIHC. The high expression of CDCA4 in LIHC is associated with prognostic significance and is highly expressed in T cell subtypes, providing a new therapeutic target and potential therapeutic strategy for LIHC.

Clinical significance of RNA methylation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy with high mortality rates and poor prognosis. Recent advances in high-throughput sequencing and bioinformatic technologies have greatly enhanced the understanding of the genetic and epigenetic changes in liver cancer. Among these changes, RNA methylation, the most prevalent internal RNA modification, has emerged as a significant contributor of the development and progression of HCC. Growing evidence has reported significantly abnormal levels of RNA methylation and dysregulation of RNA-methylation-related enzymes in HCC tissues and cell lines. These alterations in RNA methylation play a crucial role in the regulation of various genes and signaling pathways involved in HCC, thereby promoting tumor progression. Understanding the pathogenesis of RNA methylation in HCC would help in developing prognostic biomarkers and targeted therapies for HCC. Targeting RNA-methylation-related molecules has shown promising potential in the management of HCC, in terms of developing novel prognostic biomarkers and therapies for HCC. Exploring the clinical application of targeted RNA methylation may provide new insights and approaches for the management of HCC. Further research in this field is warranted to fully understand the functional roles and underlying mechanisms of RNA methylation in HCC. In this review, we described the multifaceted functional roles and potential mechanisms of RNA methylation in HCC. Moreover, the prospects of clinical application of targeted RNA methylation for HCC management are discussed, which may provide the basis for subsequent in-depth research on RNA methylation in HCC.

Rifaximin on epigenetics and autophagy in animal model of hepatocellular carcinoma secondary to metabolic-dysfunction associated steatotic liver disease

BACKGROUND

Prevalence of hepatocellular carcinoma (HCC) is increasing, especially in patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

AIM

To investigate rifaximin (RIF) effects on epigenetic/autophagy markers in animals.

METHODS

Adult Sprague-Dawley rats were randomly assigned (n = 8, each) and treated from 5-16 wk: Control [standard diet, water plus gavage with vehicle (Veh)], HCC [high-fat choline deficient diet (HFCD), diethylnitrosamine (DEN) in drinking water and Veh gavage], and RIF [HFCD, DEN and RIF (50 mg/kg/d) gavage]. Gene expression of epigenetic/autophagy markers and circulating miRNAs were obtained.

RESULTS

All HCC and RIF animals developed metabolic-dysfunction associated steatohepatitis fibrosis, and cirrhosis, but three RIF-group did not develop HCC. Comparing animals who developed HCC with those who did not, miR-122, miR-34a, tubulin alpha-1c (Tuba-1c), metalloproteinases-2 (Mmp2), and metalloproteinases-9 (Mmp9) were significantly higher in the HCC-group. The opposite occurred with Becn1, coactivator associated arginine methyltransferase-1 (Carm1), enhancer of zeste homolog-2 (Ezh2), autophagy-related factor LC3A/B (Map1 Lc3b), and p62/sequestosome-1 (p62/SQSTM1)-protein. Comparing with controls, Map1 Lc3b, Becn1 and Ezh2 were lower in HCC and RIF-groups (P < 0.05). Carm1 was lower in HCC compared to RIF (P < 0.05). Hepatic expression of Mmp9 was higher in HCC in relation to the control; the opposite was observed for p62/Sqstm1 (P < 0.05). Expression of p62/SQSTM1 protein was lower in the RIF-group compared to the control (P = 0.024). There was no difference among groups for Tuba-1c, Aldolase-B, alpha-fetoprotein, and Mmp2 (P > 0.05). miR-122 was higher in HCC, and miR-34a in RIF compared to controls (P < 0.05). miR-26b was lower in HCC compared to RIF, and the inverse was observed for miR-224 (P < 0.05). There was no difference among groups regarding miR-33a, miR-143, miR-155, miR-375 and miR-21 (P > 0.05).

CONCLUSION

RIF might have a possible beneficial effect on preventing/delaying liver carcinogenesis through epigenetic modulation in a rat model of MASLD-HCC.

Gas7 attenuates hepatocellular carcinoma progression and chemoresistance through the PI3K/Akt signaling pathway

Growth arrest-specific gene 7 (Gas7) was involved in various cellular functions, although its specific roles and molecular mechanisms in hepatocellular carcinoma (HCC) remained unclear. So the current study was to investigate the role of Gas7 in HCC. Our findings revealed that Gas7 was downregulated in various HCC cell lines and low Gas7 expression was associated with decreased overall survival in patients with HCC. Additionally, our functional assays showed that Gas7 inhibited cell proliferation and migration, induced cell cycle arrest, apoptosis, and autophagy, and enhanced oxaliplatin sensitivity by inhibiting the PI3K/Akt signaling pathway. We also observed that transcription factorSp1 was responsible for inhibiting Gas7. These findings provide insights into the role and elucidated a potential mechanism of Gas7 in HCC progression and metastasis. It was also observed that the Sp1/Gas7/PI3K/Akt axis was critical for malignant phenotype and oxaliplatin sensitivity in HCC. Therefore, Gas7 can be considered as a prognostic predictor and therapeutic target for HCC.

Benefit and harm of waiting time in liver transplantation for HCC

Liver transplantation is the most successful treatment for limited-stage HCC. The waiting time for liver transplantation (LT) can be a critical factor affecting the oncological prognosis and outcome of patients with HCC. Efficient strategies to optimize waiting time are essential to maximize the benefits of LT and to reduce the harm of delay in transplantation. The ever-increasing demand for donor livers emphasizes the need to improve the organization of the waiting list for transplantation and to optimize organ availability for patients with and without HCC. Current progress in innovations to expand the donor pool includes the implementation of living donor LT and the use of grafts from extended donors. By expanding selection criteria, an increased number of patients are eligible for transplantation, which necessitates criteria to prevent futile transplantations. Thus, the selection criteria for LT have evolved to include not only tumor characteristics but biomarkers as well. Enhancing our understanding of HCC tumor biology through the analysis of subtypes and molecular genetics holds significant promise in advancing the personalized approach for patients. In this review, the effect of waiting time duration on outcome in patients with HCC enlisted for LT is discussed.

MCF2L-AS1 promotes the biological behaviors of hepatocellular carcinoma cells by regulating the miR-33a-5p/FGF2 axis

Long noncoding RNA MCF2L-AS1 functions in the development of cancers like lung cancer, ovarian cancer, and colorectal cancer. Notwithstanding, its function in hepatocellular carcinoma (HCC) stays obscure. Our research probes its role in MHCC97H and HCCLM3 cell proliferation, migration, and invasion. qRT-PCR gauged MCF2L-AS1 and miR-33a-5p expressions in HCC tissues. CCK8, colony formation, Transwell, and EdU assays detected HCC cell proliferation, invasion, and migration, respectively. The xenograft tumor model was built to confirm the MCF2L-AS1-mediated role in HCC cell growth. Western blot and immunohistochemistry detected FGF2 expression in HCC tissues. Bioinformatics analysis predicted the targeted relationships between MCF2L-AS1 or FGF2 and miR-33a-5p, which were further examined through dual-luciferase reporter gene and pull-down assays. MCF2L-AS1 was expressed highly in HCC tissues and cells. MCF2L-AS1 upregulation enhanced HCC cells' proliferation, growth, migration, and invasion and reduced apoptosis. miR-33a-5p was demonstrated as an underlying target of MCF2L-AS1. miR-33a-5p impeded HCC cells' malignant behaviors. MCF2L-AS1 overexpression reversed miR-33a-5p-mediated effects. MCF2L-AS1 knockdown enhanced miR-33a-5p and negatively regulated FGF2 protein. miR-33a-5p targeted and inhibited FGF2. miR-33a-5p overexpression or FGF2 knockdown inhibited MCF2L-AS1-mediated oncologic effects in MHCC97H. By modulating miR-33a-5p/FGF2, MCF2L-AS1 exerts a tumor-promotive function in HCC. The MCF2L-AS1-miR-33a-5p-FGF2 axis may provide new therapeutic targets for HCC treatment.

5-Azacytidine promotes HCC cell metastasis by up-regulating RDH16 expression

The level of DNA methylation could affect the expression of tumor promoting and tumor suppressor genes. DNA methyltransferase inhibitors could reduce high methylation levels in cancer and inhibit the progression of a variety of cancers, including HCC. However, the pro-metastatic effect of DNA methyltransferase inhibitors in some cancers suggest the potential risk of their use. Whether DNA methyltransferase inhibitors also promote metastasis in HCC remains unclear. Our study will explore the effect of DNA methyltransferase inhibitor 5-Azacytidine on HCC metastasis. Our study found that 5-Azacytidine inhibited the proliferation of HCC cells while promoting in vitro and in vivo metastasis of HCC. Mechanistically, our study showed that 5-Azacytidine increased the expression of RDH16 by decreasing the methylation of RDH16 gene promoter. RDH16 is a highly methylated gene and its expression is very low in hepatocellular carcinoma. 5-Azacytidine promoted the migration of hepatocellular carcinoma cells by increasing the expression of RDH16. Our results suggest that 5-Azacytidine up-regulates the expression of RDH16 by decreasing the methylation level of RDH16, and then promoting HCC metastasis. These findings suggest that 5-Azacytidine and even other DNA methyltransferase inhibitors may have the risk of promoting metastasis in HCC treatment. RDH16 could be used as a pro-metastasis biomarker in the treatment of HCC with DNA methyltransferase inhibitors.

Biological function analysis of ARHGAP39 as an independent prognostic biomarker in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common subtype of liver cancer, with a high morbidity and low survival rate. Rho GTPase activating protein 39 (ARHGAP39) is a crucial activating protein of Rho GTPases, a novel target in cancer therapy, and it was identified as a hub gene for gastric cancer. However, the expression and role of ARHGAP39 in hepatocellular carcinoma remain unclear. Accordingly, the cancer genome atlas (TCGA) data were used to analyze the expression and clinical value of ARHGAP39 in hepatocellular carcinoma. Further, the LinkedOmics tool suggested functional enrichment pathways for ARHGAP39. To investigate in depth the possible role of ARHGAP39 on immune infiltration, we analyzed the relationship between ARHGAP39 and chemokines in HCCLM3 cells. Finally, the GSCA website was used to explore drug resistance in patients with high ARHGAP39 expression. Studies have shown that ARHGAP39 is highly expressed in hepatocellular carcinoma and relevant to clinicopathological features. In addition, the overexpression of ARHGAP39 leads to a poor prognosis. Besides, co-expressed genes and enrichment analysis showed a correlation with the cell cycle. Notably, ARHGAP39 may worsen the survival of hepatocellular carcinoma patients by increasing the level of immune infiltration through chemokines. Moreover, N6-methyladenosine (m6A) modification-related factors and drug sensitivity were also found to be associated with ARHGAP39. In brief, ARHGAP39 is a promising prognostic factor for hepatocellular carcinoma patients that is closely related to cell cycle, immune infiltration, m6A modification, and drug resistance.

Air pollution and liver cancer: A systematic review

Air pollution has previously been linked to several adverse health outcomes, but the potential association between air pollution and liver cancer remains unclear. We searched PubMed, EMBASE, and Web of Science from inception to 10 October 2021, and manually reviewed the references of relevant papers to further identify any related literature investigating possible associations between air pollution and liver cancer. Risk estimates values were represented by statistical associations based on quantitative analyses. A total of 13 cohort studies obtained from 11 articles were included, with 10,961,717 participants. PM_2.5 was the most frequently examined pollutant (included in 11 studies), followed by NO₂ and NO_x (included in 6 studies), and fewer studies focused on other pollutants (PM_{2.5 absorbance}, PM₁₀, PM_2.5-10, O₃, and BC). In all the 16 associations for liver cancer mortality, 14 associations reported the effect of PM_2.5 on liver cancer mortality. Eight associations on PM_2.5 were significant, showing a suggestive association between PM_2.5 and liver cancer mortality. Among 24 associations shown by risk estimates for liver cancer incidence, most associations were not statistically significant. For other air pollutants, no positive associations were presented in these studies. PM_2.5 was the most frequently examined pollutant, followed by NO₂ and NO_x, and fewer studies focused on other pollutants. PM_2.5 was associated with liver cancer mortality, but there was no association for other air pollutants. Future research should use advanced statistical methods to further assess the impact of multiple air pollutants on liver cancer in the changing socio-environmental context.

Long Noncoding RNA H19: A Novel Oncogene in Liver Cancer

Liver cancer is the second leading cause of cancer-related death globally, with limited treatment options. Recent studies have demonstrated the critical role of long noncoding RNAs (lncRNAs) in the pathogenesis of liver cancers. Of note, mounting evidence has shown that lncRNA H19, an endogenous noncoding single-stranded RNA, functions as an oncogene in the development and progression of liver cancer, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), the two most prevalent primary liver tumors in adults. H19 can affect many critical biological processes, including the cell proliferation, apoptosis, invasion, and metastasis of liver cancer by its function on epigenetic modification, H19/miR-675 axis, miRNAs sponge, drug resistance, and its regulation of downstream pathways. In this review, we will focus on the most relevant molecular mechanisms of action and regulation of H19 in the development and pathophysiology of HCC and CCA. This review aims to provide valuable perspectives and translational applications of H19 as a potential diagnostic marker and therapeutic target for liver cancer disease.

Novel Gene Signatures Promote Epithelial-Mesenchymal Transition (EMT) in Glucose Deprivation-Based Microenvironment to Predict Recurrence-Free Survival in Hepatocellular Carcinoma

Background

Current research studies have suggested that glucose deprivation (GD)-based tumor microenvironment (TME) can promote epithelial-mesenchymal transition (EMT) of tumor cells, leading to tumor invasion and metastasis. However, no one has yet studied detailedly the synthetic studies that include GD features in TME with EMT status. In our research, we comprehensively developed and validated a robust signature regarding GD and EMT status to provide prognostic value for patients with liver cancer.

Methods

GD and EMT status were estimated with transcriptomic profiles based on WGCNA and t-SNE algorithms. Two cohorts of training (TCGA_LIHC) and validation (GSE76427) datasets were analyzed with the Cox regression and logistic regression analyses. We identified a 2-mRNA signature to establish a GD-EMT-based gene risk model for the prediction of HCC relapse.

Results

Patients with significant GD-EMT status were divided into two subgroups: GD^low/EMT^low and GD^high/EMT^high, with the latter having significantly worse recurrence-free survival (P < 0.01). We employed the least absolute shrinkage and selection operator (LASSO) technique as a method for HNF4A and SLC2A4 filtering and constructing a risk score for risk stratification. In the multivariate analysis, this risk score predicted recurrence-free survival (RFS) in both the discovery and validation cohorts and remained valid in patients stratified by TNM stage and age at diagnosis. The nomogram that combines risk score and TNM stage as well as age produces improved performance and net benefits in the analysis of calibration and decision curves in training and validation groups.

Conclusions

The GD-EMT-based signature predictive model may provide a prognosis classifier for HCC patients with a high risk of postoperative recurrence to decrease the relapse rate.

Integrins in human hepatocellular carcinoma tumorigenesis and therapy

ABSTRACT

Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.

Epigenetic inhibition of lncRNA GMDS-AS1 by methyltransferase ESET promoted cell viability and metastasis of hepatocellular carcinoma

BACKGROUND

Long noncoding RNA (lncRNAs) GMDS-AS1 has been reported as a tumor regulator in tumor growth and metastasis, but its effect in hepatocellular carcinoma (HCC) remains unclear. ESET, a histone H3K9 methyl-transferase, is involved in epigenomic regulation of tumor progression in multiple cancers. However, the correlation between ESET and lncRNA in HCC is less reported.

METHODS

Quantitative real-time PCR (qRT-PCR) was taken to determine the expression of ESET and GMDS-AS1. Western blot was taken to determine the target protein levels of ESET and GMDS-AS1. Online database and bioinformatics analysis were used to screen abnormally expressed genes. Luciferase assay was performed to confirm the binding of GMDS-AS1 and PSMB1. Ki67 and Edu were used for evaluated the proliferation of tumor cells. ChIP assay was performed to verify the relationship between H3K9me1 and lncRNA GMDS-AS1 promoter. Transwell was taken to determine the migration and invasion ability of tumor cells. CCK-8 was used for determining the viability of tumor cells. Flow cytometry was performed to detect the cell cycle of tumor cells.

RESULTS

The expression of GMDS-AS1 was decreased and the expression of ESET was increased in HCC. GMDS-AS1 inhibition contributed to tumor development, and this effect was closely related to epigenetic inhibition of GMDS-AS1 by ESET. PSMB1, a downstream target of GMDS-AS1, promoted the tumor proliferation and was negatively regulated by GMDS-AS1.

CONCLUSION

Our result demonstrates anti-tumorigenic traits of lncRNA GMDS-AS1 in HCC and explains its pattern of regulation mediated by ESET. Our work unmasked an essential role of GMDS-AS1 in HCC progression and detected a novel pathway for ESET to promote HCC.

Roles of conventional and complementary therapies in recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the fourth leading cause of cancer-related deaths in the world. HCC has a reported recurrence rate of 70%-80% after 5 years of follow-up. Controlling tumor recurrence is the most critical factor associated with HCC mortality. Conventional salvage therapies for recurrent HCC include re-hepatectomy or liver transplantation, transcatheter arterial chemoembolization, Y-90, target therapy, and immunotherapy; however, these conventional treatment modalities have yet to achieve consistently favorable outcomes. Meanwhile, previous studies have demonstrated that conventional therapies in combination with traditional Chinese medicine (TCM), acupuncture, moxibustion or dietary supplements could notably benefit patients with HCC recurrence by strengthening and augmenting the overall management strategy. However, systemic reviews related to the interactions between complementary therapies and conventional therapy in recurrent HCC are limited. In this review, we discuss the molecular mechanisms underlying the functions of complementary therapies for recurrent HCC, which include augmenting the local control to improve the congestion status of primary tumors and reducing multicentric tumor occurrence via inducing autophagy, apoptosis or cell cycle arrest. TCM and its derivatives may play important roles in helping to control HCC recurrence by inhibiting epithelial-mesenchymal transition, migration, invasion, and metastasis, inhibiting cancer stem cells, and ameliorating drug resistance.

Role of Plasma methylated SEPT9 for Predicting Microvascular Invasion and Tumor Proliferation in Hepatocellular Carcinoma

Background: Methylated SEPT9 (mSEPT9) has a role in the occurrence and development of hepatocellular carcinoma (HCC). Here, we studied the significance of plasma mSEPT9 for predicting prognosis-associated pathological parameters in patients with HCC. Methods: We retrospectively analyzed data from 205 subjects, including 111 HCC patients, 53 patients with at-risk liver disease (ARD) and 41 healthy donors (HDs). Analysis of plasma mSEPT9 was performed using methylation-specific polymerase chain reaction. Levels of mSEPT9 among different groups were compared using a nonparametric Mann-Whitney U test or a one-way ANOVA test. Correlations between pretreatment plasma mSEPT9 and clinicopathological characteristics were analyzed using the Chi-square. Univariate and multivariate analyses were used to identify factors related to microvascular invasion (MVI). Performance of variables for MVI prediction was evaluated by receiver operating characteristics curve. Results: A specific increase of plasma mSEPT9 in HCC was found when compared with ARD and HDs (HCC vs ARD, P  =  1.1  ×  10^-5 and HCC vs HDs, P  =  3.7  ×  10^-10). Pretreatment plasma mSEPT9 was significantly correlated tumor number (P  =  .004), tumor size (P  =  4.6  ×  10^-5), MVI (P  =  .002) and Barcelona Clinic Liver Cancer stage (P  =  .012). Levels of plasma mSEPT9 correlated significantly with Ki67 expression in tumor (r  =  0.356, P  =  1.3  ×  10^-4). Univariate and multivariate analyses showed that plasma mSEPT9 and serum protein induced by vitamin K absence or antagonist-II (PIVKA-II) were independent predictors for MVI. A combination of these 2 markers exhibited a larger areas under the curve (areas under the curve [AUC]  =  0.72) than mSEPT9 or PIVKA alone (AUC  =  0.67 and 0.65), especially in early-stage HCC. Conclusions: Plasma mSEPT9 is a promising noninvasive biomarker for predicting MVI and tumor proliferation in HCC. Integration plasma mSEPT9 detection into clinical settings might facilitate the patient management.

The roles of histone modifications in tumorigenesis and associated inhibitors in cancer therapy

Histone modifications are key factors in chromatin packaging, and are responsible for gene regulation during cell fate determination and development. Abnormal alterations in histone modifications potentially affect the stability of the genome and disrupt gene expression patterns, leading to many diseases, including cancer. In recent years, mounting evidence has shown that various histone modifications altered by aberrantly expressed modifier enzymes contribute to tumor development and metastasis through the induction of epigenetic, transcriptional, and phenotypic changes. In this review, we will discuss the existing histone modifications, both well-studied and rare ones, and their roles in solid tumors and hematopoietic cancers, to identify the molecular pathways involved and investigate targeted therapeutic drugs to reorganize the chromatin and enhance cancer treatment efficiency. Finally, clinical inhibitors of histone modifications are summarized to better understand the developmental stage of cancer therapy in using these drugs to inhibit the histone modification enzymes.

Novel Insights into MEG3/miR664a-3p/ADH4 Axis and Its Possible Role in Hepatocellular Carcinoma from an in Silico Perspective

Hepatocellular carcinoma (HCC) is a complex disease involving altered interactomes of transcripts and proteins. MicroRNAs (miRNAs) are small-noncoding RNAs that can interact with specific gene transcripts and an array of other vital endogenous non-coding RNAs (lncRNAs) that can influence gene expression. Maternally Expressed Gene 3 (MEG3) is an imprinted lncRNA that is reported to be downregulated in HCC (in both cell lines and tumors). Alcohol Dehydrogenase 4 (ADH4) is a well-known prognostic protein biomarker for predicting the survival outcomes of patients with hepatocellular carcinoma whose expression is regulated by miR-664a-3p, which is upregulated in HCC. In this study, we performed a battery of robust and systematic in silico analyses to predicate the possible lncRNA-miRNA interactions between MEG3, miR-664a-3p, and ADH4. miRNA-mRNA and lncRNA-miRNA hybrid structures were primarily obtained, and the minimum free energies (MFEs) for the 3'UTR (Untranslated Regions) of ADH4-miR-664a-3p and the 3'UTR of MEG3-miR-664a-3p interactions were assessed to predict the stability of the obtained RNA heteroduplex hybrids. The hybrid with the least minimum free energy (MFE) was considered to be the most favorable. The MFEs were around -28.1 kcal/mol and -31.3 kCal/mol for the ADH4-miR-664a-3p and MEG3-miR-66a-3p RNA hybrids, respectively. This demonstrated that lncRNA-MEG3 might be a competitive endogenous RNA that acts as a molecular sponge for miR-664a-3p. In summary, our interaction analyses results predict the significance of the MEG3/miR-664a-3p/ADH4 axis, where MEG3 downregulation results in miR-664a-3p overexpression and the subsequential underexpression of ADH4 in HCC, as a novel axis of interest that demands further validation.

Targeted Therapies for Hepatocellular Carcinoma Treatment: A New Era Ahead-A Systematic Review

Hepatocellular carcinoma (HCC) remains one of the most common malignancies and the third cause of cancer-related death worldwide, with surgery being the best prognostic tool. Among the well-known causative factors of HCC are chronic liver virus infections, chronic virus hepatitis B (HBV) and chronic hepatitis virus C (HCV), aflatoxins, tobacco consumption, and non-alcoholic liver disease (NAFLD). There is a need for the development of efficient molecular markers and alternative therapeutic targets of great significance. In this review, we describe the general characteristics of HCC and present a variety of targeted therapies that resulted in progress in HCC therapy.

Epigenetics in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and has a high fatality rate. Genetic and epigenetic aberrations are commonly observed in HCC. The epigenetic processes include chromatin remodelling, histone alterations, DNA methylation, and noncoding RNA (ncRNA) expression and are connected with the progression and metastasis of HCC. Due to their potential reversibility, these epigenetic alterations are widely targeted for the development of biomarkers. In-depth understanding of the epigenetics of HCC is critical for developing rational clinical strategies that can provide a meaningful improvement in overall survival and prediction of therapeutic outcomes. In this article, we have summarised the epigenetic modifications involved in HCC progression and highlighted the potential biomarkers for diagnosis and drug development.

The role of RNA modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly mortal type of primary liver cancer. Abnormal epigenetic modifications are present in HCC, and RNA modification is dynamic and reversible and is a key post-transcriptional regulator. With the in-depth study of post-transcriptional modifications, RNA modifications are aberrantly expressed in human cancers. Moreover, the regulators of RNA modifications can be used as potential targets for cancer therapy. In RNA modifications, N6-methyladenosine (m6A), N7-methylguanosine (m7G), and 5-methylcytosine (m5C) and their regulators have important regulatory roles in HCC progression and represent potential novel biomarkers for the confirmation of diagnosis and treatment of HCC. This review focuses on RNA modifications in HCC and the roles and mechanisms of m6A, m7G, m5C, N1-methyladenosine (m1A), N3-methylcytosine (m3C), and pseudouridine (ψ) on its development and maintenance. The potential therapeutic strategies of RNA modifications are elaborated for HCC.

Roles and regulation of histone acetylation in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is the most frequent malignant tumor of the liver, but its prognosis is poor. Histone acetylation is an important epigenetic regulatory mode that modulates chromatin structure and transcriptional status to control gene expression in eukaryotic cells. Generally, histone acetylation and deacetylation processes are controlled by the opposing activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). Dysregulation of histone modification is reported to drive aberrant transcriptional programmes that facilitate liver cancer onset and progression. Emerging studies have demonstrated that several HDAC inhibitors exert tumor-suppressive properties via activation of various cell death molecular pathways in HCC. However, the complexity involved in the epigenetic transcription modifications and non-epigenetic cellular signaling processes limit their potential clinical applications. This review brings an in-depth view of the oncogenic mechanisms reported to be related to aberrant HCC-associated histone acetylation, which might provide new insights into the effective therapeutic strategies to prevent and treat HCC.

The effects of valproic acid on skin healing: experimental study in rats

Purpose:

To recognize the effects of valproic acid (VPA), an epigenetic drug, on the skin healing process.

Methods:

Sixty male Wistar rats were divided into two groups: the experiment treated with VPA (100 mg/kg/day); and the control, with 0.9% sodium chloride by gavage. Skin healing was studied in three moments (the third, the seventh, and the 14th day), evaluating the parameters: inflammatory reaction and its intensity (anti-LCA), angiogenesis (anti-CD34), collagen I and III (anti-collagen I, anti-collagen III and Picrosirius-red F3BA) and myofibroblasts (anti-alpha-AMS).

Results:

The inflammatory reaction was acute or sub-acute in both groups on the third day. On the seventh and the 14th day, chronic predominated in the control (p=0.006), and sub-acute in the experiment (p=0.020). There was a greater number of leukocytes in the group treated only on the third day (p=0.036). The number of vessels was lower in the treated group at the three times (p3=0.002, p7<0.001, and p14=0.027). Myofibroblasts were rare in the third day and moderate quantity in the remaining periods. Collagen I density was higher in the control at the three times (p<0.001) and collagen III in the treated group (p<0.001).

Conclusions:

VPA led to a more intense inflammatory reaction, decreased angiogenesis and collagen deposition, especially type I collagen.

miR-200a-3p- and miR-181-5p-Mediated HOXB5 Upregulation Promotes HCC Progression by Transcriptional Activation of EGFR

Background

Hepatocellular carcinoma (HCC) remains a worldwide burden. However, the mechanisms behind the malignant biological behavior of HCC remain unclear. The homeobox (HOX) family could act as either promoters or suppressors in different kinds of malignancies. Our study discovered the role of HOXB5 in regulating HCC progression.

Methods

The HOXB5 expression was assessed by RT-PCR analysis in human HCC samples and cell lines. HOXB5 transcriptional regulation of the EGFR was verified by the luciferase reporter assay and chromatin immunoprecipitation experiment. The oncogenic role of HOXB5 in HCC progression was analyzed by CCK8, colony-forming, and transwell assays.

Results

Upregulation of HOXB5 was found in human HCC, and was strongly correlated with HCC tumor size, tumor-nodule metastasis, TNM stage, and relatively unfavorable OS and DFS. Ectopic expression of HOXB5 promoted the capacity of cell growth and clonogenicity, while the inhibition of HOXB5 decreased the proliferation and clonogenicity potential in vitro by CCK8 and colony-forming assays. In addition, HOXB5 also promoted cell migration by transwell experiment. Mechanism studies elucidated that HOXB5 triggers HCC progression via direct transcriptional activation of EGFR. The upregulation of HOXB5 is regulated by miR-200a-3p and miR-181-5p. Transfection of miR-200a-3p and miR-181-5p mimics blocked the cell proliferation and migration regulated by HOXB5, while overexpression of the 3′-UTR mutant HOXB5 abolished the suppressive effect of miR-200a-3p and miR-181-5p, but not the wild-type HOXB5.

Conclusion

HOXB5 is a promising prognostic factor in human HCC. Targeting miR-200a-3p and the miR-181-5p/HOXB5/EGFR signaling pathway may provide new options for the treatment strategies of HCC.

SETD3 Methyltransferase Regulates PLK1 Expression to Promote In Situ Hepatic Carcinogenesis

Background

The development of a new strategy to overcome chemoresistance to hepatocellular carcinoma (HCC) treatment is a long-standing issue. We have previously found that upregulated SETD3 levels are closely correlated with HCC. This study aims to explore the mechanism underlying how upregulation of SETD3 promotes liver carcinogenesis.

Methods

RNA-Sequencing analysis was used to explore the correlation of SETD3 with regulatory targets. In vitro assays including cell proliferation and migration were performed to study the oncogenic roles of SETD3 and PLK1. Western blotting, immunohistochemical staining, and blood biochemical assays were performed to examine protein expression or pathological index in tumor tissues and mice liver tissues. Luciferase reporter system and chromatin immunoprecipitation assays were used to explore the mechanism.

Results

We revealed that SETD3 regulates gene expression in subgroups, including cell division, cell proliferation, and cell cycle, in hepatocellular tumor cells. We found that SETD3 upregulation is associated with elevated PLK1 level in both hepatic tumor cells and clinical liver tissues. We further showed that overexpression of SETD3 promoted tumor cell proliferation and migration, whereas inhibition of PLK1 activity attenuated these phenotypes caused by SETD3. By taking advantage of the Sleep Beauty transposase system, we confirmed that upregulated mouse Setd3 promoted hepatic carcinogenesis in situ, but knockdown of mouse Plk1 mitigated Setd3-promoted tumorigenesis in mice. Mechanistically, we showed that SETD3 could be recruited to the promoter of PLK1 gene to facilitate PLK1 transcription.

Conclusions

Our data demonstrate that elevated SETD3 may promote HCC by enhancing PLK1 expression, which suggests that SETD3 may act as a potential drug target combined with PLK1 inhibition to treat HCC.

Elevated Small Nuclear Ribonucleoprotein Polypeptide an Expression Correlated With Poor Prognosis and Immune Infiltrates in Patients With Hepatocellular Carcinoma

Background

Elevated Small Nuclear Ribonucleoprotein Polypeptide A (SNRPA) can enhance tumor cell growth and proliferation in various cancers. However, rarely studies focus on the comprehensive analysis of SNRPA in hepatocellular carcinoma (HCC).

Methods

TCGA and GEO databases were used to analyze the mRNA expression of SNRPA in HCC. Protein expression of SNAPA was validated using immunohistochemistry. Stably transfected HCC cells were used to investigate the role of SNRPA in the progression of HCC. The functional enrichment analysis was utilized for the biological function prediction. The CIBERSORT and ssGSEA algorithms were used to evaluate the composition of the tumor microenvironment and immunocyte infiltration ratio.

Results

The SNRPA expression was upregulated in HCC and positively correlated with tumor stage and grade. SNRPA overexpression were independent risk factors for poor overall survival (OS) and recurrence-free survival (RFS). In patients with early-stage disease, low alpha-fetoprotein expression, and better differentiation, SNRPA still exhibited the excellent prognostic value. Knockdown of SNRPA inhibited the proliferation and migration while promoting the apoptosis of HCC cells. Higher methylation of the CpG site cg16596691 correlated with longer OS in HCC patients. Genes co-expressed with SNRPA were overexpressed in HCC and correlated with shorter OS. The GO and KEGG enrichment analysis showed that SNRPA expression was related to mRNA splicing, spliceosome signaling. GSEA demonstrated that the main enrichment pathway of SNRPA-related differential genes was spliceosome signaling, cell cycle signaling, P53 signaling pathway, T cell receptor signaling pathway, natural killer cell-mediated signaling. CIBERSORT and ssGSEA algorithm revealed that SNRPA was mainly associated with the higher proportion of CD8+T cells, T cells follicular helper, T cells regulatory, Macrophages M0, and the lower proportion of T cells CD4 memory resting, NK cells resting, Monocytes, and Mast cells resting.

Conclusion

Elevated SNRPA enhances tumor cell proliferation and correlated with poor prognosis and immune infiltrates in patients with HCC.

Study of tRNA-Derived Fragment tRF-20-S998LO9D in Pan-Cancer

Objective

The purpose is to study the effect of tRNA-derived fragments (tRFs) on pan-cancer through bioinformatics.

Methods

The expression information of tRF-20-S998LO9D, a type of tRF-5, was retrieved through MINTbase in pan-cancer and verified by qPCR. We preliminarily explored the effect of tRF-20-S998LO9D on cell proliferation in breast cancer and lung cancer cell lines. Then an online KM-plotter provided by OncotRF was used to discover the prognostic significance. GO/KEGG analyses were executed to predict the potential mechanism of tRF-20-S998LO9D in cancer.

Results

We found that tRF-20-S998LO9D was highly expressed in a variety of cancers like breast invasive carcinoma, head and neck squamous cell carcinoma, kidney renal clear cell carcinoma, lung squamous cell carcinoma, pheochromocytoma and paraganglioma, and uterine corpus endometrial carcinoma. Inhibition of tRF-20-S998LO9D led to reduced cell proliferation in breast cancer (MCF-7) and lung squamous cell carcinoma (SK-MES-1) cells. Elevated tRF-20-S998LO9D indicated poor prognosis in a variety of cancers. tRF-20-S998LO9D might be involved in multiple cancer-related pathways.

Conclusion

We concluded that tRF-20-S998LO9D was upregulated and negatively correlated with prognosis of a variety of cancers. It may be a potential cancer-promoting marker in pan-cancer.

Human gut-microbiome-derived propionate coordinates proteasomal degradation via HECTD2 upregulation to target EHMT2 in colorectal cancer

The human microbiome plays an essential role in the human immune system, food digestion, and protection from harmful bacteria by colonizing the human intestine. Recently, although the human microbiome affects colorectal cancer (CRC) treatment, the mode of action between the microbiome and CRC remains unclear. This study showed that propionate suppressed CRC growth by promoting the proteasomal degradation of euchromatic histone-lysine N-methyltransferase 2 (EHMT2) through HECT domain E3 ubiquitin protein ligase 2 (HECTD2) upregulation. In addition, EHMT2 downregulation reduced the H3K9me2 level on the promoter region of tumor necrosis factor α-induced protein 1 (TNFAIP1) as a novel direct target of EHMT2. Subsequently, TNFAIP1 upregulation induced the apoptosis of CRC cells. Furthermore, using Bacteroides thetaiotaomicron culture medium, we confirmed EHMT2 downregulation via upregulation of HECTD2 and TNFAIP1 upregulation. Finally, we observed the synergistic effect of propionate and an EHMT2 inhibitor (BIX01294) in 3D spheroid culture models. Thus, we suggest the anticancer effects of propionate and EHMT2 as therapeutic targets for colon cancer treatment and may provide the possibility for the synergistic effects of an EHMT2 inhibitor and microbiome in CRC treatment.

MBD3 promotes hepatocellular carcinoma progression and metastasis through negative regulation of tumour suppressor TFPI2

Background

The mechanism of recurrence and metastasis of hepatocellular carcinoma (HCC) is complex and challenging. Methyl-CpG binding domain protein 3 (MBD3) is a key epigenetic regulator involved in the progression and metastasis of several cancers, but its role in HCC remains unknown.

Methods

MBD3 expression in HCC was detected by immunohistochemistry and its association with clinicopathological features and patient’s survival was analysed. The effects of MBD3 on hepatoma cells growth and metastasis were investigated, and the mechanism was explored.

Results

MBD3 is significantly highly expressed in HCC, associated with the advanced tumour stage and poor prognosis in HCC patients. MBD3 promotes the growth, angiogenesis and metastasis of HCC cells by inhibiting the tumour suppressor tissue factor pathway inhibitor 2 (TFPI2). Mechanistically, MBD3 can inhibit the TFPI2 transcription via the Nucleosome Remodeling and Deacetylase (NuRD) complex-mediated deacetylation, thus reactivating the activity of matrix metalloproteinases (MMPs) and PI3K/AKT signaling pathway, leading to the progression and metastasis of HCC

Conclusions

Our results unravel the novel regulatory function of MBD3 in the progression and metastasis of HCC and identify MBD3 as an independent unfavourable prognostic factor for HCC patients, suggesting its potential as a promising therapeutic target as well.

The role of epigenetic modifications in Colorectal Cancer Metastasis

Distant metastasis is the major contributor to the high mortality rate of colorectal cancer (CRC). To overcome the poor prognosis caused by distant metastasis, the mechanisms of CRC metastasis should be further explored. Epigenetic events are the main mediators of gene regulation and further affect tumor progression. Recent studies have found that some epigenetic enzymes are often dysregulated or mutated in multiple tumor types, which prompted us to study the roles of these enzymes in CRC metastasis. In this review, we summarized the alteration of enzymes related to various modifications, including histone modification, nonhistone modification, DNA methylation, and RNA methylation, and their epigenetic mechanisms during the progression of CRC metastasis. Existing data suggest that targeting epigenetic enzymes is a promising strategy for the treatment of CRC metastasis.

IL-6 Promotes Hepatocellular Carcinoma Invasion by Releasing Exosomal miR-133a-3p

Interleukin-6 (IL-6), an important inflammatory cytokine, is a key factor regulating cancer metastasis. Cancer cells can modulate their tumorigenic abilities by sorting specific microRNAs (miRNAs) as exosomes into the tumor microenvironment. The relationship between IL-6 and exosomal miRNAs related to hepatocellular carcinoma (HCC) metastasis remains to be elucidated. We examined the metastatic ability of HCC cells after IL-6 treatment and found that miR-133a-3p was sorted into exosomes after IL-6 stimulation and was subsequently released into the tumor microenvironment. In vitro analysis confirmed that exosomal miR-133a-3p acted as a tumor suppressor in HCC. Bioinformatic analysis revealed several signaling pathways and hub genes (CREB1, VCP, CALM1, and YES1) regulated by miR-133a-3p. Survival curves further verified the important roles of hub genes in the prognosis of patients with HCC. It is envisaged that the IL-6/miR-133a-3p axis may be related to the activation of CREB1, VCP, CALM1, and YES1. Our findings provide new insights into the role of exosomal miRNA-mediated tumor progression under inflammatory conditions.

Methylation‑associated inactivation of JPH3 and its effect on prognosis and cell biological function in HCC

In recent years, researchers have found that epigenetics plays an important role in the occurrence and development of hepatocellular carcinoma (HCC). DNA methylation is involved in the proliferation and metastasis of HCC. However, the junctophilin 3 (JPH3) level and the potential regulatory mechanism of its DNA methylation in HCC remain uncertain. In the present study, 73 HCC samples were enrolled to analyze the expression of JPH3. Reverse‑transcription quantitative PCR, western blotting and immunohistochemistry were used to detect the expression of JPH3 in HCC. Kaplan‑Meier method and Cox regression analysis were applied to evaluate the prognostic impact of JPH3 on HCC patients. DNA methylation‑specific PCR and bisulfite Sanger sequencing were used to detect the degree of DNA methylation of JPH3 in HCC. The demethylation drug 5‑Aza‑2'‑deoxycytidine (5‑Aza) was used to reduce the DNA methylation of JPH3. The role of JPH3 in the malignant biological behavior of HCC by promoting epithelial‑mesenchymal transition (EMT) was confirmed by functional cell experiments. The results showed that JPH3 exhibited low levels in HCC tissues and cell lines. HCC patients with low expression of JPH3 had poor survival outcomes. JPH3 had higher DNA methylation levels in HCC tissues and cell lines. When the demethylation drug 5‑Aza was used to reduce the degree of methylation of JPH3, its protein expression level was significantly increased and it significantly inhibited the malignant biological behavior of HCC cells. Additionally, effective increase in the expression of JPH3 through gene regulation technology also inhibited the proliferation, invasion and migration of HCC cells. After altering the DNA methylation level of JPH3, the EMT of HCC cells was also affected. Therefore, our study demonstrated the inactivation of JPH3 by promoter methylation and its function as a tumor suppressor in HCC. JPH3 may serve as a biomarker for early diagnosis and as a potential therapeutic target for HCC.

Exosomal miR-543 Inhibits the Proliferation of Ovarian Cancer by Targeting IGF2

Objective

Ovarian cancer (OvCa) is the most lethal gynaecological malignancy worldwide. We aimed to illustrate the potential function and molecular mechanism of exosomal microRNA-543 (miR-543) in the oncogenesis and development of OvCa.

Methods

Differentially expressed microRNAs in exosomes derived from OvCa cell lines were identified by bioinformatic analysis and verified by RT-PCR. Cell proliferation ability was estimated by clonogenic and 5-ethynyl-2′-deoxyuridine assays in vitro and in vivo. Potential involved pathways and targets of exosomal miRNAs were analysed using DIANA and verified by pyrosequencing, glucose quantification, dual-luciferase reporter experiments, and functional rescue assays.

Results

Bioinformatic analysis identified miR-543 and its potential target genes involved in the cancer-associated proteoglycan pathway. The expression of miR-543 was significantly decreased in exosomes derived from OvCa cell lines, patient serum, and OvCa tissues, while the mRNA levels of insulin-like growth factor 2 (IGF2) were increased. Furthermore, the overexpression of miR-543 resulted in the suppression of OvCa cell proliferation in vitro and in vivo. Moreover, miR-543 was significantly negatively correlated with IGF2 in OvCa tissues in comparison with paracarcinoma tissues. Notably, upregulation of miR-543 led to increased cell supernatant glucose levels and suppressed cell growth, which was rescued by overexpression of IGF2.

Conclusions

Exosomal miR-543 participates in the proteoglycan pathway to suppress cell proliferation by targeting IGF2 in OvCa.

Identification of Key Histone Modifications and Hub Genes for Colorectal Cancer Metastasis

Background:

Epithelial-Mesenchymal Transition (EMT) and its reverse Mesenchymal- Epithelial Transition (MET) are essential for tumor cells metastasis. However, the effect of epigenetic modifications on this transition is unclear.

Objective:

We aimed to explore the key histone modifications and hub genes of EMT/MET during Colorectal Cancer (CRC) metastasis.

Method:

The differentially expressed genes and differentially histone modified genes were identified. Based on the histone modification features, the up- and down-regulated genes were predicted by Random Forest algorithm. Through protein-protein interaction network and Cytoscape analysis, the hub genes with histone modification changes were selected. GO, KEGG and survival analyses were performed to confirm the importance of the hub genes.

Results:

It was found that H3K79me3 plays an important role in EMT/MET. And the 200-300bp and 400-500bp downstream of TSS may be the key regulatory regions of H3K79me3. Moreover, we found that the expression of the hub genes was down-regulated in EMT and then up-regulated in MET. And the changes of the hub genes expression were consistent with the changes of H3K79me3 signal in the specific regions of the genome. Finally, the hub genes KRT8 and KRT18 were involved in the metastasis process and were significantly related to the survival time.

Conclusion:

H3K79me3 may be crucial for EMT/MET, and the hub genes KRT8 and KRT18 may be the key genes in this process.

Cyclin-Dependent Kinase 4 is expected to be a therapeutic target for hepatocellular carcinoma metastasis using integrated bioinformatic analysis

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide. HCC cells possess biological characteristics of high invasion and metastasis. In this respect, to prevent cancer cell invasion and metastasis and early active intervention, we herein screened through the TCGA database for further prognostic analysis including overall survival and disease-free survival . The Kaplan-Meier curve suggested that Cyclin-Dependent Kinase 4 (CDK4) might be an independent prognostic factor for HCC. Moreover, we performed mRNA expression analysis to measure CDK4 levels in normal liver tissues and HCC tissues, and immunohistochemistry analysis to detect protein level of CDK4 in Non-tumor tissue and HCC tissues . Our findings indicated that the expression of CDK4 was significantly higher in tumor tissues compared with Non-tumor tissue in HCC, which increased from HCC stage 1 to 3. Furthermore, the results of transwell-assay indicated that knocking down CDK4 significantly suppresses the invasion and migration of HCC cells, and the results of bioinformatics analysis revealed that genes closely associated with CDK4 are potentially worthy of further investigation. Additionally, the results of Western Blot indicated CDK4 regulates epithelial mesenchymal transition in HCC,and CDK4 appears to regulate EMT and HCC progression via the Wnt/β-catenin pathway. Collectively, this study found the key target gene through bioinformatic analysis and further functional validation through cell experiments. In particular, CDK4 is anticipated to become a crucial hub gene to snipe the metastasis of cancer cells in HCC.Abbreviations: Hepatocellular carcinoma (HCC);Cyclin-Dependent Kinase 4(CDK4);Genomic Data Commons (GDC); genes; EC, Endometrial cancer; GEO, gene expression omnibus; GO, Gene Ontology; GSEA, Gene set enrichment analysis; KEGG, Database; TCGA, The Cancer Genome Atlas; TSGs, tumor suppressor genes;epithelial mesenchymal transition (EMT).

Mechanism and Therapeutic Opportunities of Histone Modifications in Chronic Liver Disease

Chronic liver disease (CLD) represents a global health problem, accounting for the heavy burden of disability and increased health care utilization. Epigenome alterations play an important role in the occurrence and progression of CLD. Histone modifications, which include acetylation, methylation, and phosphorylation, represent an essential part of epigenetic modifications that affect the transcriptional activity of genes. Different from genetic mutations, histone modifications are plastic and reversible. They can be modulated pharmacologically without changing the DNA sequence. Thus, there might be chances to establish interventional solutions by targeting histone modifications to reverse CLD. Here we summarized the roles of histone modifications in the context of alcoholic liver disease (ALD), metabolic associated fatty liver disease (MAFLD), viral hepatitis, autoimmune liver disease, drug-induced liver injury (DILI), and liver fibrosis or cirrhosis. The potential targets of histone modifications for translation into therapeutics were also investigated. In prospect, high efficacy and low toxicity drugs that are selectively targeting histone modifications are required to completely reverse CLD and prevent the development of liver cirrhosis and malignancy.

Prediction and prognostic significance of ALOX12B and PACSIN1 expression in gastric cancer by genome-wide RNA expression and methylation analysis

Background

Stomach adenocarcinoma (STAD) is one of the common gastrointestinal cancers, characterized by late discovery and metastasis. However, research of gene methylation and expression in gastric cancer (GC) metastasis has been quite limited. This study aimed to investigate the altered gene expression patterns between metastasis and non-metastasis samples using high-throughput RNA and methylation profiles from a large number of patients. Another aim was to identify a specific potential metastasis biomarker, with the ability to predict the metastasis possibility and prognosis of patients with STAD.

Methods

In this study, we integrated The Cancer Genome Atlas (TCGA) program STAD datasets, analyzed the RNA expression and DNA methylation data between non-metastasis (M0) and distant metastasis (M1) samples, and evaluated the candidate biomarker in survival and prognosis of GC.

Results

Among all patients enrolled, 329 with M0 and M1 information were positive for RNA analysis, and 353 with M0 and M1 information were positive for methylation analysis. We found 29 upregulated and 200 downregulated genes in RNA level, and 5,046 hypermethylated and 8,563 hypomethylated probes in methylation level. Among these genes, we found high RNA expression level and low DNA methylation level of ALOX12B and PACSIN1 in GC metastasis samples. Patients with high expression of these 2 genes had poor overall survival (OS), progression-free survival (PFS), and post-progression survival (PPS).

Conclusions

The expression levels of ALOX12B and PACSIN1 were higher in the metastasis than non-metastasis group, and participants with high expression of these 2 genes were found to have poor survival. The genes ALOX12B and PACSIN1 are potential biomarkers of metastasis and poor prognosis, especially in early stage GC, and provide additional information for subsequent comprehensive treatment of GC.

Histone methylatic modification mediates the tumor-suppressive activity of curcumol in hepatocellular carcinoma via an Hotair/EZH2 regulatory axis

ETHNOPHARMACOLOGICAL RELEVANCE

Curcuma kwangsiensis S. G. Lee & C. F. Liang (Guangxi ezhu, in Chinese) has been used as a traditional Chinese medicine (TCM) for approximately 2000 years. Curcumol is one of the major bioactive components of this herb, which has been demonstrated possesses anti-cancer properties, and was recorded in the Chinese Pharmacopoeia 2020 edition. However, most studies mainly focused on the superficial anti-cancer activity, the underlying mechanism remains poorly understood.

AIM OF THE STUDY

In the present study, we aimed to investigate the anti-tumor effect of Curcumol on hepatocellular carcinoma (HCC), and elucidate its underlying mechanism from the perspective of epigenetic modification.

MATERIALS AND METHODS

The potential anti-cancer properties of Curcumol were evaluated in HepG2 and SMMC-7721 cells. Its effects on cell growth, cell cycle, apoptosis and migration were examined in these HCC cells. Moreover, the lncRNA HOX transcript antisense intergenic RNA (Hotair) and histone methylatic modification were detected by qPCR and Western blotting assays.

RESULTS

In the present study, Curcumol was illustrated to suppress cell growth in HCC cells via inducing apoptosis and cell cycle arrest. And it was also found that Curcumol inhibited the invasion and metastasis of HCC as well. As for the mechanism investigation, it was showed that lncRNA Hotair was significantly downregulated by Curcumol in HCC cells. As is well known, Hotair recruited histone methyltransferase enhancer of zeste homolog 2 (EZH2) to exert transcriptional regulation. Our results showed that EZH2 were downregulated by Curcumol in HCC cells, and thus disrupted the trimethylation of H3K9 and H3K27 which were specifically catalyzed by EZH2.

CONCLUSIONS

In conclude, our results demonstrated that Curcumol suppressed tumor growth and metastasis via an Hotair/EZH2/histone modification regulatory axis.

RNA methyltransferase NSUN2 promotes growth of hepatocellular carcinoma cells by regulating fizzy-related-1 in vitro and in vivo

The aim of the study was to investigate the role of NSUN2 (NOP2/Sun RNA Methyltransferase Family Member 2) in hepatocellular carcinoma (HCC). The expressions of NSUN2 and FZR1 were measured. Cell viability, proliferation, and apoptosis were assessed. HCC xenograft in nude mouse model was established. Tumor weight and volume were examined. Tumor tissues were collected for immunohistochemistry (IHC). TCGA database analysis and clinical sample testing suggested that the transcript levels of NSUN2 and FZR1 were increased in HCC tissues. NSUN2 knockdown inhibited HCC cell viability and proliferation, and promoted cell apoptosis. Moreover, the effects of NSUN2 could be countered by overexpressing FZR1. In animal experiment, NSUN2 silencing suppressed tumor growth in nude mice by downregulating FZR1. In conclusion, NSUN2 has a regulatory effect on HCC cell proliferation and apoptosis. NSUN2 knockout could inhibit cellular processes in HCC and tumor growth, likely via FZR1 inhibition. This finding has not only revealed the role of NSUN2 in HCC growth, but also suggests a promising target for HCC treatment.

The Expression and Function of Circadian Rhythm Genes in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the most common and lethal form of cancer worldwide. However, its diagnosis and treatment are still dissatisfactory, due to limitations in the understanding of its pathogenic mechanism. Therefore, it is important to elucidate the molecular mechanisms and identify novel therapeutic targets for HCC. Circadian rhythm-related genes control a variety of biological processes. These genes play pivotal roles in the initiation and progression of HCC and are potential diagnostic markers and therapeutic targets. This review gives an update on the research progress of circadian rhythms, their effects on the initiation, progression, and prognosis of HCC, in a bid to provide new insights for the research and treatment of HCC.

DNA methylation-based profiling reveals distinct clusters with survival heterogeneity in high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) is the most common type of epigenetically heterogeneous ovarian cancer. Methylation typing has previously been used in many tumour types but not in HGSOC. Methylation typing in HGSOC may promote the development of personalized care. The present study used DNA methylation data from The Cancer Genome Atlas database and identified four unique methylation subtypes of HGSOC. With the poorest prognosis and high frequency of residual tumours, cluster 4 featured hypermethylation of a panel of genes, which indicates that demethylation agents may be tested in this group and that neoadjuvant chemotherapy may be used to reduce the possibility of residual lesions. Cluster 1 and cluster 2 were significantly associated with metastasis genes and metabolic disorders, respectively. Two feature CpG sites, cg24673765 and cg25574024, were obtained through Cox proportional hazards model analysis of the CpG sites. Based on the methylation level of the two CpG sites, the samples were classified into high- and low-risk groups to identify the prognostic information. Similar results were obtained in the validation set. Taken together, these results explain the epigenetic heterogeneity of HGSOC and provide guidance to clinicians for the prognosis of HGSOC based on DNA methylation sites.

Hepatocellular carcinoma: metastatic pathways and extra-hepatic findings

Although a small portion of patients with hepatocellular carcinoma (HCC) have radiologically evident extrahepatic disease at the initial presentation, a larger number of them develop metastatic disease later during the course of treatment or after definitive treatment. Furthermore, early metastatic disease could be overlooked by imaging due to small size and non-specificity of findings. Extrahepatic spread of HCC occurs via different pathways and is directly fueled by tumor biology and its molecular characteristics. Early and accurate detection of extrahepatic disease in patients with HCC has significant impact on management and selection of treatment options. Additionally, precise staging of disease will allow for better prediction of survival and outcome. Different pathways of regional and systemic spread of HCC with their proposed mechanisms and relevant underlying molecular derangement will be discussed in this article. Potential roles in management of patients with HCC will be discussed and reviewed in this article.