miR-107-mediated decrease of HMGCS2 indicates poor outcomes and promotes cell migration in hepatocellular carcinoma

Targeting non-coding RNAs and N6-methyladenosine modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common form of primary liver cancers, accounts for a significant portion of cancer-related death globally. However, the molecular mechanisms driving the onset and progression of HCC are still not fully understood. Emerging evidence has indicated that non-protein-coding regions of genomes could give rise to transcripts, termed non-coding RNA (ncRNA), forming novel functional driving force for aberrant cellular activity. Over the past decades, overwhelming evidence has denoted involvement of a complex array of molecular function of ncRNAs at different stages of HCC tumorigenesis and progression. In this context, several pre-clinical studies have highlighted the potentials of ncRNAs as novel therapeutic modalities in the management of human HCC. Moreover, N6-methyladenosine (m6A) modification, the most prevalent form of internal mRNA modifications in mammalian cells, is essential for the governance of biological processes within cells. Dysregulation of m6A in ncRNAs has been implicated in human carcinogenesis, including HCC. In this review, we will discuss dysregulation of several hallmark ncRNAs (miRNAs, lncRNAs, and circRNAs) in HCC and address the latest advances for their involvement in the onset and progression of HCC. We also focus on dysregulation of m6A modification and various m6A regulators in the etiology of HCC. In the end, we discussed the contemporary preclinical and clinical application of ncRNA-based and m6A-targeted therapies in HCC.

Hmgcs2 is the hub gene in diabetic cardiomyopathy and is negatively regulated by Hmgcs2, promoting high glucose-induced cardiomyocyte injury

BACKGROUND

Diabetic cardiomyopathy (DCM) represents a major cause of heart failure and a large medical burden worldwide. This study screened the potentially regulatory targets of DCM and analyzed their roles in high glucose (HG)-induced cardiomyocyte injury.

METHODS

Through GEO database, we obtained rat DCM expression chips and screened differentially expressed genes. Rat cardiomyocytes (H9C2) were induced with HG. 3-hydroxy-3-methylglutarylcoenzyme A synthase 2 (Hmgcs2) and microRNA (miR)-363-5p expression patterns in cells were measured by real-time quantitative polymerase chain reaction or Western blot assay, with the dual-luciferase assay to analyze their binding relationship. Then, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, lactate dehydrogenase assay, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, enzyme-linked immunosorbent assay, and various assay kits were applied to evaluate cell viability, cytotoxicity, apoptosis, inflammation responses, and oxidative burden.

RESULTS

Hmgcs2 was the vital hub gene in DCM. Hmgcs2 was upregulated in HG-induced cardiomyocytes. Hmgcs2 downregulation increased cell viability, decreased TUNEL-positive cell number, reduced HG-induced inflammation and oxidative stress. miR-363-5p is the upstream miRNA of Hmgcs2. miR-363-5p overexpression attenuated HG-induced cell injury.

CONCLUSIONS

Hmgcs2 had the most critical regulatory role in DCM. We for the first time reported that miR-363-5p inhibited Hmgcs2 expression, thereby alleviating HG-induced cardiomyocyte injury.

Roles of peroxisome proliferator-activated receptors in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the main pathological type of liver cancer, is linked to risk factors such as viral hepatitis, alcohol intake and non-alcoholic fatty liver disease (NAFLD). Recent advances have greatly improved our understanding that NAFLD is playing a major risk factor for HCC. Peroxisome proliferator-activated receptors (PPARs) are a class of transcription factors divided into three subtypes: PPARα (PPARA), PPARδ/β (PPARD) and PPARγ (PPARG). As important nuclear receptors, PPARs are involved in many physiological processes, and PPARs can improve NAFLD by regulating lipid metabolism, accelerating fatty acid oxidation and inhibiting inflammation. In recent years, some studies have shown that PPARs can participate in the occurrence and development of HCC by regulating metabolic pathways. In addition, PPAR modulators have been reported to inhibit the proliferation and metastasis of HCC cells and can enhance the curative effect of conventional treatments. This article reviews the role of PPARs in the occurrence and development of HCC, as well as its value in the diagnosis, treatment and prognosis of HCC, in order to provide directions for future research.

Decoding hepatocarcinogenesis from a noncoding RNAs perspective

Being a leading lethal malignancy worldwide, the pathophysiology of hepatocellular carcinoma (HCC) has gained a lot of interest. Yet, underlying mechanistic basis of the liver tumorigenesis is poorly understood. The role of some coding genes and their respective translated proteins, then later on, some noncoding RNAs (ncRNAs) such as microRNAs have been extensively studied in context of HCC pathophysiology; however, the implication of long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) in HCC is indeed less investigated. As a subclass of the ncRNAs which has been elusive for long time ago, lncRNAs was found to be involved in plentiful cellular functions such as DNA, RNA, and proteins regulation. Hence, it is undisputed that lncRNAs dysregulation profoundly contributes to HCC via diverse etiologies. Accordingly, lncRNAs represent a hot research topic that requires prime focus in HCC. In this review, the authors discuss breakthrough discoveries involving lncRNAs and circRNAs dysregulation that have contributed to the contemporary concepts of HCC pathophysiology and how these concepts could be leveraged as potential novel diagnostic and prognostic HCC biomarkers. Further, this review article sheds light on future trends, thereby discussing the pathological roles of lncRNAs and circRNAs in HCC proliferation, migration, and epithelial-to-mesenchymal transition. Along this line of reasoning, future recommendations of how these targets could be exploited to achieve effective HCC-related drug development is highlighted.

p21-activated kinase 4 suppresses fatty acid β-oxidation and ketogenesis by phosphorylating NCoR1

PPARα corepressor NCoR1 is a key regulator of fatty acid β-oxidation and ketogenesis. However, its regulatory mechanism is largely unknown. Here, we report that oncoprotein p21-activated kinase 4 (PAK4) is an NCoR1 kinase. Specifically, PAK4 phosphorylates NCoR1 at T1619/T2124, resulting in an increase in its nuclear localization and interaction with PPARα, thereby repressing the transcriptional activity of PPARα. We observe impaired ketogenesis and increases in PAK4 protein and NCoR1 phosphorylation levels in liver tissues of high fat diet-fed mice, NAFLD patients, and hepatocellular carcinoma patients. Forced overexpression of PAK4 in mice represses ketogenesis and thereby increases hepatic fat accumulation, whereas genetic ablation or pharmacological inhibition of PAK4 exhibites an opposite phenotype. Interestingly, PAK4 protein levels are significantly suppressed by fasting, largely through either cAMP/PKA- or Sirt1-mediated ubiquitination and proteasome degradation. In this way, our findings provide evidence for a PAK4-NCoR1/PPARα signaling pathway that regulates fatty acid β-oxidation and ketogenesis.

Construction of a lipid metabolism-related risk model for hepatocellular carcinoma by single cell and machine learning analysis

One of the most common cancers is hepatocellular carcinoma (HCC). Numerous studies have shown the relationship between abnormal lipid metabolism-related genes (LMRGs) and malignancies. In most studies, the single LMRG was studied and has limited clinical application value. This study aims to develop a novel LMRG prognostic model for HCC patients and to study its utility for predictive, preventive, and personalized medicine. We used the single-cell RNA sequencing (scRNA-seq) dataset and TCGA dataset of HCC samples and discovered differentially expressed LMRGs between primary and metastatic HCC patients. By using the least absolute selection and shrinkage operator (LASSO) regression machine learning algorithm, we constructed a risk prognosis model with six LMRGs (AKR1C1, CYP27A1, CYP2C9, GLB1, HMGCS2, and PLPP1). The risk prognosis model was further validated in an external cohort of ICGC. We also constructed a nomogram that could accurately predict overall survival in HCC patients based on cancer status and LMRGs. Further investigation of the association between the LMRG model and somatic tumor mutational burden (TMB), tumor immune infiltration, and biological function was performed. We found that the most frequent somatic mutations in the LMRG high-risk group were CTNNB1, TTN, TP53, ALB, MUC16, and PCLO. Moreover, naïve CD8+ T cells, common myeloid progenitors, endothelial cells, granulocyte-monocyte progenitors, hematopoietic stem cells, M2 macrophages, and plasmacytoid dendritic cells were significantly correlated with the LMRG high-risk group. Finally, gene set enrichment analysis showed that RNA degradation, spliceosome, and lysosome pathways were associated with the LMRG high-risk group. For the first time, we used scRNA-seq and bulk RNA-seq to construct an LMRG-related risk score model, which may provide insights into more effective treatment strategies for predictive, preventive, and personalized medicine of HCC patients.

Molecular Mechanisms for Ketone Body Metabolism, Signaling Functions, and Therapeutic Potential in Cancer

The ketone bodies (KBs) β-hydroxybutyrate and acetoacetate are important alternative energy sources for glucose during nutrient deprivation. KBs synthesized by hepatic ketogenesis are catabolized to acetyl-CoA through ketolysis in extrahepatic tissues, followed by the tricarboxylic acid cycle and electron transport chain for ATP production. Ketogenesis and ketolysis are regulated by the key rate-limiting enzymes, 3-hydroxy-3-methylglutaryl-CoA synthase 2 and succinyl-CoA:3-oxoacid-CoA transferase, respectively. KBs participate in various cellular processes as signaling molecules. KBs bind to G protein-coupled receptors. The most abundant KB, β-hydroxybutyrate, regulates gene expression and other cellular functions by inducing post-translational modifications. KBs protect tissues by regulating inflammation and oxidative stress. Recently, interest in KBs has been increasing due to their potential for treatment of various diseases such as neurological and cardiovascular diseases and cancer. Cancer cells reprogram their metabolism to maintain rapid cell growth and proliferation. Dysregulation of KB metabolism also plays a role in tumorigenesis in various types of cancer. Targeting metabolic changes through dietary interventions, including fasting and ketogenic diets, has shown beneficial effects in cancer therapy. Here, we review current knowledge of the molecular mechanisms involved in the regulation of KB metabolism and cellular signaling functions, and the therapeutic potential of KBs and ketogenic diets in cancer.

HMGCS2 Mediation of Ketone Levels Affects Sorafenib Treatment Efficacy in Liver Cancer Cells

Primary liver cancer is the fifth leading death of cancers in men, and hepatocellular carcinoma (HCC) accounts for approximately 90% of all primary liver cancer cases. Sorafenib is a first-line drug for advanced-stage HCC patients. Sorafenib is a multi-target kinase inhibitor that blocks tumor cell proliferation and angiogenesis. Despite sorafenib treatment extending survival, some patients experience side effects, and sorafenib resistance does occur. 3-Hydroxymethyl glutaryl-CoA synthase 2 (HMGCS2) is the rate-limiting enzyme for ketogenesis, which synthesizes the ketone bodies, β-hydroxybutyrate (β-HB) and acetoacetate (AcAc). β-HB is the most abundant ketone body which is present in a 4:1 ratio compared to AcAc. Recently, ketone body treatment was found to have therapeutic effects against many cancers by causing metabolic alternations and cancer cell apoptosis. Our previous publication showed that HMGCS2 downregulation-mediated ketone body reduction promoted HCC clinicopathological progression through regulating c-Myc/cyclin D1 and caspase-dependent signaling. However, whether HMGCS2-regulated ketone body production alters the sensitivity of human HCC to sorafenib treatment remains unclear. In this study, we showed that HMGCS2 downregulation enhanced the proliferative ability and attenuated the cytotoxic effects of sorafenib by activating expressions of phosphorylated (p)-extracellular signal-regulated kinase (ERK), p-P38, and p-AKT. In contrast, HMGCS2 overexpression decreased cell proliferation and enhanced the cytotoxic effects of sorafenib in HCC cells by inhibiting ERK activation. Furthermore, we showed that knockdown HMGCS2 exhibited the potential migratory ability, as well as decreasing zonula occludens protein (ZO)-1 and increasing c-Myc expression in both sorafenib-treated Huh7 and HepG2 cells. Although HMGCS2 overexpression did not alter the migratory effect, expressions of ZO-1, c-Myc, and N-cadherin decreased in sorafenib-treated HMGCS2-overexpressing HCC cells. Finally, we investigated whether ketone treatment influences sorafenib sensitivity. We showed that β-HB pretreatment decreased cell proliferation and enhanced antiproliferative effect of sorafenib in both Huh7 and HepG2 cells. In conclusion, this study defined the impacts of HMGCS2 expression and ketone body treatment on influencing the sorafenib sensitivity of liver cancer cells.

Functional and Clinical Significance of Dysregulated microRNAs in Liver Cancer

Simple Summary

Liver cancer has a high mortality rate. Here, we retrospectively discuss the current progress and dilemmas in the clinical research and treatment of liver cancer. We primarily focus on microRNAs because of their extremely high value in applications and research. We discuss whether microRNAs can be used for the development of better biomarkers and/or therapeutic drugs, and address the difficulties, requirements for improved diagnostic technologies, and side effects related to microRNA-based drugs.

Abstract

Liver cancer is the leading cause of cancer-related mortality in the world. This mainly reflects the lack of early diagnosis tools and effective treatment methods. MicroRNAs (miRNAs) are a class of non-transcribed RNAs, some of which play important regulatory roles in liver cancer. Here, we discuss microRNAs with key impacts on liver cancer, such as miR-122, miR-21, miR-214, and miR-199. These microRNAs participate in various physiological regulatory pathways of liver cancer cells, and their modulation can have non-negligible effects in the treatment of liver cancer. We discuss whether these microRNAs can be used for better clinical diagnosis and/or drug development. With the advent of novel technologies, fast, inexpensive, and non-invasive RNA-based biomarker research has become a new mainstream approach. However, the clinical application of microRNA-based markers has been limited by the high sequence similarity among them and the potential for off-target problems. Therefore, researchers particularly value microRNAs that are specific to or have special functions in liver cancer. These include miR-122, which is specifically expressed in the liver, and miR-34, which is necessary for the replication of the hepatitis C virus in liver cancer. Clinical treatment drugs have been developed based on miR-34 and miR-122 (MRX34 and Miravirsen, respectively), but their side effects have not yet been overcome. Future research is needed to address these weaknesses and establish a feasible microRNA-based treatment strategy for liver cancer.

Epigenetic inactivation of hydroxymethylglutaryl CoA synthase reduces ketogenesis and facilitates tumor cell motility in clear cell renal carcinoma

Previously, we have reported that the dysregulation of ketogenesis plays an important role in the carcinogenesis of clear cell renal cell carcinoma (ccRCC). Here, we demonstrate decreased expression of the HMGCS2 gene in ccRCC, a critical enzyme for the synthesis of the ketone body β-hydroxybutyrate (β-OHB). We found that the reduced transcription of the HMGCS2 gene in ccRCC cells was significantly correlated to a higher relative methylation rate in its promotor region. The higher methylation rate in the region of the transcription start site and 1st exon of the HMGCS2 gene was, in turn, correlated with a worse clinical outcome for patients. The transcription of HMGCS2 was possible to restore by treatment with 5-aza-2'-deoxycytidine and with the histone deacetylase inhibitor β-OHB. Therefore, the low levels of the HMGCS2 enzyme in ccRCC may be the consequence of hypermethylation of the HMGCS2 promotor. The ensuing reduction in the ketone body levels further suppresses the transcription of HMGCS2 via a feedback loop. Ectopic expression of HMGCS2 attenuates the migration and invasion of ccRCC but does not affect the proliferative capacity of ccRCC cells in vitro. In addition, we showed that ectopic expression of HMGCS2 boosts the intracellular levels of β-OHB and that exogenously applied β-OHB suppresses the motility and invasion of ccRCC. Our study reveals crosstalk between genes that regulate metabolism and their metabolites, thus providing a better understanding of the epigenetic mechanism involved in ccRCC carcinogenesis and suggesting opportunities for metabolic therapy of tumors. Initially, we suggest that the mRNA level of HMGCS2 could serve as a potentially valuable diagnostic (AUC = 0.918, p < 0.001) and prognostic biomarker.

SLC38A4 functions as a tumour suppressor in hepatocellular carcinoma through modulating Wnt/β-catenin/MYC/HMGCS2 axis

BACKGROUND

Many molecular alterations are shared by embryonic liver development and hepatocellular carcinoma (HCC). Identifying the common molecular events would provide a novel prognostic biomarker and therapeutic target for HCC.

METHODS

Expression levels and clinical relevancies of SLC38A4 and HMGCS2 were investigated by qRT-PCR, western blot, TCGA and GEO datasets. The biological roles of SLC38A4 were investigated by functional assays. The downstream signalling pathway of SLC38A4 was investigated by qRT-PCR, western blot, immunofluorescence, luciferase reporter assay, TCGA and GEO datasets.

RESULTS

SLC38A4 silencing was identified as an oncofetal molecular event. DNA hypermethylation contributed to the downregulations of Slc38a4/SLC38A4 in the foetal liver and HCC. Low expression of SLC38A4 was associated with poor prognosis of HCC patients. Functional assays demonstrated that SLC38A4 depletion promoted HCC cellular proliferation, stemness and migration, and inhibited HCC cellular apoptosis in vitro, and further repressed HCC tumorigenesis in vivo. HMGCS2 was identified as a critical downstream target of SLC38A4. SLC38A4 increased HMGCS2 expression via upregulating AXIN1 and repressing Wnt/β-catenin/MYC axis. Functional rescue assays showed that HMGCS2 overexpression reversed the oncogenic roles of SLC38A4 depletion in HCC.

CONCLUSIONS

SLC38A4 downregulation was identified as a novel oncofetal event, and SLC38A4 was identified as a novel tumour suppressor in HCC.

HMGCS2 in metabolic pathways was associated with overall survival in hepatocellular carcinoma: A LASSO-derived study

This integrated bioinformatic study aimed to investigate potential prognostic candidates in hepatocellular carcinoma (HCC). In the GSE14520, GSE101685, and The Cancer Genome Atlas (TCGA) datasets, differentially expressed genes (DEGs) were identified and functional pathways of common DEGs were enriched. The least absolute shrinkage and selection operator (LASSO) model was used to screen the potential parameters associated with overall survival (OS) in HCC patients. Metabolic pathways were the most significantly enriched functional pathways of common DEGs in these three datasets. After LASSO model analysis, HMGCS2, UGP2, BCLC staging and TNM staging were screened as potential prognostic candidates for OS in HCC patients in GSE14520. HMGCS2 in the metabolic pathway was significantly downregulated in tumor tissues and peripheral blood mononuclear cells in HCC patients (all p < 0.05). Cox regression model indicated that HMGCS2 might be associate with OS in HCC patients in GSE14520 and in the TCGA (p = 0.029 and p = 0.05, respectively). Kaplan-Meier analysis demonstrated that HMGCS2 downregulation in tumors contributed to an unfavorable OS in HCC patients, both in GSE14520 and in the TCGA (p = 0.0001 and p = 0.0002, respectively). Additionally, HMGCS2 was significantly downregulated in HCC patients with high alpha-fetoprotein (AFP), main tumor size >5 cm, multinodular, advanced tumor staging including BCLC, TNM and CLIP (all p < 0.05). HMGCS2 was involved in metabolic pathways, and downregulated HMGCS2 in tumors was associated with unfavorable OS in HCC patients.

Long non-coding RNA FEZF1-AS1 promotes the proliferation and metastasis of hepatocellular carcinoma via targeting miR-107/Wnt/β-catenin axis

Hepatocellular carcinoma (HCC) is a public health problem around the world, with the molecular mechanisms being still incompletely clear. This study was carried out to explore the role and mechanism of long-noncoding RNA (lncRNA) FEZF1-AS1 in HCC progression. RNA sequencing and quantitative real time polymerase chain reaction (qRT- PCR) were applied to identify differently expressed lncRNAs in HCC tissues and adjacent normal tissues. CCK8 assay was adopted to test cell proliferation and flow cytometry was taken to detect cell apoptosis. Wound healing assay and transwell experiment were performed to determine cell migration and invasion. To validate the function of lncRNA FEZF1-AS1 in vivo, tumor-burdened models were established. The results showed that lncRNA FEZF1-AS1 level was prominently enhanced in HCC tumor specimens and overexpression of FEZF1-AS1 promoted the proliferation, migration and invasion of HCC cells. In mechanism, overexpression of FEZF1-AS1 reduced the expression of miR-107 which inhibited the activation of Wnt/β-catenin signaling. Overexpression of β-catenin promoted cell proliferation, migration and invasion which were inhibited by FEZF1-AS1 downregulation. In conclusion, our study demonstrated that FEZF1-AS1 promoted HCC progression through activating Wnt/β-catenin signaling by targeting miR-107, which provided a novel target for the therapy of HCC.

Whole-transcriptome Analysis of Fully Viable Energy Efficient Glycolytic-null Cancer Cells Established by Double Genetic Knockout of Lactate Dehydrogenase A/B or Glucose-6-Phosphate Isomerase

BACKGROUND/AIM

Nearly all mammalian tumors of diverse tissues are believed to be dependent on fermentative glycolysis, marked by elevated production of lactic acid and expression of glycolytic enzymes, most notably lactic acid dehydrogenase (LDH). Therefore, there has been significant interest in developing chemotherapy drugs that selectively target various isoforms of the LDH enzyme. However, considerable questions remain as to the consequences of biological ablation of LDH or upstream targeting of the glycolytic pathway.

MATERIALS AND METHODS

In this study, we explore the biochemical and whole transcriptomic effects of CRISPR-Cas9 gene knockout (KO) of lactate dehydrogenases A and B [LDHA/B double KO (DKO)] and glucose-6-phosphate isomerase (GPI KO) in the human colon cancer cell line LS174T, using Affymetrix 2.1 ST arrays.

RESULTS

The metabolic biochemical profiles corroborate that relative to wild type (WT), LDHA/B DKO produced no lactic acid, (GPI KO) produced minimal lactic acid and both KOs displayed higher mitochondrial respiration, and minimal use of glucose with no loss of cell viability. These findings show a high biochemical energy efficiency as measured by ATP in glycolysis-null cells. Next, transcriptomic analysis conducted on 48,226 mRNA transcripts reflect 273 differentially expressed genes (DEGS) in the GPI KO clone set, 193 DEGS in the LDHA/B DKO clone set with 47 DEGs common to both KO clones. Glycolytic-null cells reflect up-regulation in gene transcripts typically associated with nutrient deprivation / fasting and possible use of fats for energy: thioredoxin interacting protein (TXNIP), mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), PPARγ coactivator 1α (PGC-1α), and acetyl-CoA acyltransferase 2 (ACAA2). Other changes in non-ergometric transcripts in both KOs show losses in "stemness", WNT signaling pathway, chemo/radiation resistance, retinoic acid synthesis, drug detoxification, androgen/estrogen activation, and extracellular matrix reprogramming genes.

CONCLUSION

These findings demonstrate that: 1) The "Warburg effect" is dispensable, 2) loss of the LDHAB gene is not only inconsequential to viability but fosters greater mitochondrial energy, and 3) drugs that target LDHA/B are likely to be ineffective without a plausible combination second drug target.

Identification of a Potential PPAR-Related Multigene Signature Predicting Prognosis of Patients with Hepatocellular Carcinoma

Peroxisome proliferator-activated receptors (PPARs) and part of their target genes have been reported to be related to the progression of hepatocellular carcinoma (HCC). The prognosis of HCC is not optimistic, and more accurate prognostic markers are needed. This study focused on discovering potential prognostic markers from the PPAR-related gene set. The mRNA data and clinical information of HCC were collected from TCGA and GEO platforms. Univariate Cox and lasso Cox regression analyses were used to screen prognostic genes of HCC. Three genes (MMP1, HMGCS2, and SLC27A5) involved in the PPAR signaling pathway were selected as the prognostic signature of HCC. A formula was established based on the expression values and multivariate Cox regression coefficients of selected genes, that was, risk score = 0.1488∗expression value of MMP1 + (−0.0393)∗expression value of HMGCS2 + (−0.0479)∗expression value of SLC27A5. The prognostic ability of the three-gene signature was assessed in the TCGA HCC dataset and verified in three GEO sets (GSE14520, GSE36376, and GSE76427). The results showed that the risk score based on our signature was a risk factor with a HR (hazard ratio) of 2.72 (95%CI (Confidence Interval) = 1.87 ~ 3.95, p < 0.001) for HCC survival. The signature could significantly (p < 0.0001) distinguish high-risk and low-risk patients with poor prognosis for HCC. In addition, we further explored the independence and applicability of the signature with other clinical indicators through multivariate Cox analysis (p < 0.001) and nomogram analysis (C‐index = 0.709). The above results indicate that the combination of MMP1, HMGCS2, and SLC27A5 selected from the PPAR signaling pathway could effectively, independently, and applicatively predict the prognosis of HCC. Our research provided new insights to the prognosis of HCC.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

Glycolytic pathway candidate markers in the prognosis of oral squamous cell carcinoma: a systematic review with meta-analysis

Molecular changes that affect mitochondrial glycolysis have been associated with the maintenance of tumor cells. Some metabolic factors have already been described as predictors of disease severity and outcomes. This systematic review was conducted to answer the question: Is the glycolytic pathway correlated with the prognosis of oral squamous cell carcinoma (OSCC)? A search strategy was developed to retrieve studies in English from PubMed, Scopus, and ISI Web of Science using keywords related to squamous cell carcinoma, survival, and glycolytic pathway, with no restriction of publication date. The search retrieved 1273 publications. After the titles and abstracts were analyzed, 27 studies met inclusion criteria. Studies were divided into groups according to two subtopics, glycolytic pathways and diagnosis, which describe the glycolytic profile of OSCC tumors. Several components of tumor energy metabolism found in this review are important predictors of survival of patients with OSCC.

MicroRNA-107 inhibits proliferation and invasion of laryngeal squamous cell carcinoma cells by targeting CACNA2D1 in vitro

Our previous studies have confirmed that α2δ1 has the potential to function as a cancer stem cell marker, and CACNA2D1 is the coding gene of α2δ1. But it is unclear how microRNAs regulate the expression of the CACNA2D1 gene in laryngeal cancer cells. We detected the expressions of α2δ1 protein, microRNA-107, and CACNA2D1 in 40 pairs of laryngeal cancer tissues and adjacent normal tissues. Laryngeal squamous cell carcinoma cells, TU212 and TU686, were cultured and transfected in the blank control group, the agomiR negative control group, the agomiR-107 group, the antagomiR negative control group, or the antagomiR-107 group, and the dual-luciferase reporter assay was employed to assess the regulatory effect of microRNA-107 on CACNA2D1. Then, the effects of microRNA-107 on the biological function of laryngeal squamous cell carcinoma cells were detected by qRT-PCR, Western blot, MTT, cell migration/invasion assay, and cell colony-formation assay. Our data suggested that the protein level of α2δ1, encoded by CACNA2D1, in laryngeal carcinoma tissues was higher than that in adjacent normal tissues, while the expression of microRNA-107 was significantly decreased in laryngeal carcinoma tissues. The dual-luciferase reporter gene assay confirmed that microRNA-107 bound to the 3′-UTR two positions (202-209, 902-908) of CACNA2D1 mRNA. Moreover, the expression of CACNA2D1 and α2δ1 protein were significantly decreased in TU212 and TU686 cells transfected with microRNA-107 expression vectors (P < 0.05), and proliferation, clone formation, migration, and invasion of these cells were also reduced. Furthermore, after knocking down microRNA-107, exactly opposite results were obtained. Overexpression of microRNA-107 can inhibit the proliferation and invasion of laryngeal carcinoma cells in vitro.

Identify and Validate the Transcriptomic, Functional Network, and Predictive Validity of FBXL19-AS1 in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common neoplastic diseases worldwide. Available biomarkers are not sensitive enough for the diagnosis of HCC, hence seeking new biomarkers of HCC is urgent and challenging. The purpose of this study was to investigate the role of F-box and leucine-rich repeat protein 19-antisense RNA 1 (FBXL19-AS1) through a functional network and inquire into its diagnostic and prognostic value in HCC. A comprehensive strategy of genomic data mining, bioinformatics and experimental validation was used to evaluate the clinical value of FBXL19-AS1 in the diagnosis and prognosis of HCC and to identify the pathways in which FBXL19-AS1 might be involved. FBXL19-AS1 was up-regulated in HCC tissues, and its high expression was associated with TNM stage and poor prognosis of HCC patients. The combination of FBXL19-AS1 and alpha-fetoprotein (AFP) in plasma could prominently improve the diagnostic validity for HCC. FBXL19-AS1 might stabilize FBXL19 to reduce the amount of macrophage M1, and then promote the occurrence and development of HCC. Meanwhile, FBXL19-AS1 might participate in regulating HCC related pathways through FBXL19-AS1-miRNA-mRNA network. Our findings indicated that FBXL19-AS1 not only serves as a potential biomarker for HCC diagnosis and prognosis, but also might be functionally carcinogenic.

Molecular and Functional Roles of MicroRNAs in the Progression of Hepatocellular Carcinoma-A Review

Liver cancer is the fourth leading cause of cancer deaths globally, of which hepatocellular carcinoma (HCC) is the major subtype. Viral hepatitis B and C infections, alcohol abuse, and metabolic disorders are multiple risk factors for liver cirrhosis and HCC development. Although great therapeutic advances have been made in recent decades, the prognosis for HCC patients remains poor due to late diagnosis, chemotherapy failure, and frequent recurrence. MicroRNAs (miRNAs) are endogenous, non-coding RNAs that regulate various molecular biological phenomena by suppressing the translation of target messenger RNAs (mRNAs). miRNAs, which often become dysregulated in malignancy, control cell proliferation, migration, invasion, and development in HCC by promoting or suppressing tumors. Exploring the detailed mechanisms underlying miRNA-mediated HCC development and progression can likely improve the outcomes of patients with HCC. This review summarizes the molecular and functional roles of miRNAs in the pathogenesis of HCC. Further, it elucidates the utility of miRNAs as novel biomarkers and therapeutic targets.

Identification of potential key genes and key pathways related to clear cell renal cell carcinoma through bioinformatics analysis

Clear cell renal cell carcinoma (ccRCC) is a common malignancy of the genitourinary system and is associated with high mortality rates. However, the molecular mechanism of ccRCC pathogenesis is still unclear, which translates to few effective diagnostic and prognostic biomarkers. In this study, we conducted a bioinformatics analysis on three Gene Expression Omnibus datasets and identified 437 differentially expressed genes (DEGs) related to ccRCC development and prognosis, of which 311 and 126 genes are respectively down-regulated and up-regulated. The protein-protein interaction network of these DEGs consists of 395 nodes and 1872 interactions and 2 prominent modules. The Staphylococcus aureus infection and complement and coagulation cascades are significantly enriched in module 1 and are likely involved in ccRCC progression. Forty-two hub genes were screened, of which von Willebrand factor, TIMP metallopeptidase inhibitor 1, plasminogen, formimidoyltransferase cyclodeaminase, solute carrier family 34 member 1, hydroxyacid oxidase 2, alanine-glyoxylate aminotransferase 2, phosphoenolpyruvate carboxykinase 1, and 3-hydroxy-3-methylglutaryl-CoA synthase 2 are possibly related to the prognosis of ccRCC. The differential expression of all nine genes was confirmed by quantitative real-time polymerase chain reaction analysis of the ccRCC and normal renal tissues. These key genes are potential biomarkers for the diagnosis and prognosis of ccRCC and warrant further investigation.

Role of cellular, molecular and tumor microenvironment in hepatocellular carcinoma: Possible targets and future directions in the regorafenib era

Hepatocellular carcinoma (HCC) remains as one of the major causes of cancer-related mortality, despite the recent development of new therapeutic options. Regorafenib, an oral multikinase inhibitor, is the first systemic therapy that has a survival benefit for patients with advanced HCC that have a poor response to sorafenib. Even though regorafenib has been approved by the FDA, the clinical trial for regorafenib treatment does not show significant improvement in overall survival. The impaired efficacy of regorafenib caused by various resistance mechanisms, including epithelial-mesenchymal transitions, inflammation, angiogenesis, hypoxia, oxidative stress, fibrosis and autophagy, still needs to be resolved. In this review, we provide insight on regorafenib microenvironmental, molecular and cellular mechanisms and interactions in HCC treatment. The aim of this review is to help physicians select patients that would obtain the maximal benefits from regorafenib in HCC therapy.

HMGCS2 Mediates Ketone Production and Regulates the Proliferation and Metastasis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor worldwide; however, the traditional therapeutic approaches and survival rates are still limited. To improve current therapies, it is necessary to investigate the molecular mechanisms underlying liver cancer and to identify potential therapeutic targets. The aims of this study were to verify the mechanisms and therapeutic potential of the ketogenesis rate-limiting enzyme 3-Hydroxymethylglutaryl-CoA synthase 2 (HMGCS2) in HCC. Immunohistochemical staining of human liver disease tissue arrays showed that HMGCS2 is abundantly expressed in normal liver tissues but is downregulated in cirrhosis and HCC tissues. In HCC patients, lower HMGCS2 expression was correlated with higher pathological grades and clinical stages. In our investigation of the molecular mechanisms of HMGCS2 in HCC, we showed that knockdown of HMGCS2 decreased ketone production, which promoted cell proliferation, cell migration, and xenograft tumorigenesis by enhancing c-Myc/cyclinD1 and EMT signaling and by suppressing the caspase-dependent apoptosis pathway. Ketone body treatment reduced the proliferation- and migration-promoting effects of HMGCS2 knockdown in cells. In contrast, HMGCS2 overexpression increased the intracellular ketone level and inhibited cell proliferation, cell migration, and xenograft tumorigenesis. Finally, ketogenic diet administration significantly inhibited liver cancer cell growth in mice. Our studies highlight the potential therapeutic strategy of targeting HMGCS2-mediated ketogenesis in liver cancer.

Regulation of Ketogenic Enzyme HMGCS2 by Wnt/β-catenin/PPARγ Pathway in Intestinal Cells

The Wnt/β-catenin pathway plays a crucial role in development and renewal of the intestinal epithelium. Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), a rate-limiting ketogenic enzyme in the synthesis of ketone body β-hydroxybutyrate (βHB), contributes to the regulation of intestinal cell differentiation. Here, we have shown that HMGCS2 is a novel target of Wnt/β-catenin/PPARγ signaling in intestinal epithelial cancer cell lines and normal intestinal organoids. Inhibition of the Wnt/β-catenin pathway resulted in increased protein and mRNA expression of HMGCS2 and βHB production in human colon cancer cell lines LS174T and Caco2. In addition, Wnt inhibition increased expression of PPARγ and its target genes, FABP2 and PLIN2, in these cells. Conversely, activation of Wnt/β-catenin signaling decreased protein and mRNA levels of HMGCS2, βHB production, and expression of PPARγ and its target genes in LS174T and Caco2 cells and mouse intestinal organoids. Moreover, inhibition of PPARγ reduced HMGCS2 expression and βHB production, while activation of PPARγ increased HMGCS2 expression and βHB synthesis. Furthermore, PPARγ bound the promoter of HMGCS2 and this binding was enhanced by β-catenin knockdown. Finally, we showed that HMGCS2 inhibited, while Wnt/β-catenin stimulated, glycolysis, which contributed to regulation of intestinal cell differentiation. Our results identified HMGCS2 as a downstream target of Wnt/β-catenin/PPARγ signaling in intestinal epithelial cells. Moreover, our findings suggest that Wnt/β-catenin/PPARγ signaling regulates intestinal cell differentiation, at least in part, through regulation of ketogenesis.

Prognostic value and immune infiltration of novel signatures in clear cell renal cell carcinoma microenvironment

Growing evidence has highlighted the immune response as an important feature of carcinogenesis and therapeutic efficacy in clear cell renal cell carcinoma (ccRCC). This study categorized ccRCC cases into high and low score groups based on their immune/stromal scores generated by the ESTIMATE algorithm, and identified an association between these scores and prognosis. Differentially expressed tumor environment (TME)-related genes extracted from common upregulated components in immune and stromal scores were described using functional annotations and protein–protein interaction (PPI) networks. Most PPIs were selected for further prognostic investigation. Many additional previously neglected signatures, including AGPAT9, AQP7, HMGCS2, KLF15, MLXIPL, PPARGC1A, exhibited significant prognostic potential. In addition, multivariate Cox analysis indicated that MIXIPL and PPARGC1A were the most significant prognostic signatures, and were closely related to immune infiltration in TCGA cohort. External prognostic validation of MIXIPL and PPARGC1A was undertaken in 380 ccRCC cases from a real-world cohort. These findings indicate the relevance of monitoring and manipulation of the microenvironment for ccRCC prognosis and precision immunotherapy.

Inhibition of hepatocellular carcinoma by metabolic normalization

In two different mouse liver cancer models, we recently showed that a switch from oxidative phosphorylation (Oxphos) to glycolysis (the Warburg effect) is invariably accompanied by a marked decline in fatty acid oxidation (FAO) and a reciprocal increase in the activity of pyruvate dehydrogenase (PDH), which links glycolysis to the TCA cycle. We now show that short-term implementation of either medium-chain (MC) or long-chain (LC) high fat diets (HFDs) nearly doubled the survival of mice with c-Myc oncoprotein-driven hepatocellular carcinoma (HCC). Mechanistically, HFDs forced tumors to become more reliant on fatty acids as an energy source, thus normalizing both FAO and PDH activities. More generally, both MC- and LC-HFDs partially or completely normalized the expression of 682 tumor-dysregulated transcripts, a substantial fraction of which are involved in cell cycle control, proliferation and metabolism. That these same transcripts were responsive to HFDs in livers strongly suggested that the changes were the cause of tumor inhibition rather than its consequence. In seven different human cancer cohorts, patients with tumors containing high ratios of FAO-related:glycolysis-related transcripts had prolonged survival relative to those with low ratios. Furthermore, in 13 human cancer types, the expression patterns of transcripts encoding enzymes participating in FAO and/or cholesterol biosynthesis also correlated with significantly prolonged survival. Collectively, our results support the idea that the survival benefits of HFDs are due to a reversal of the Warburg effect and other tumor-associated metabolic and cell cycle abnormalities. They also suggest that short-term dietary manipulation, either alone or in combination with more traditional chemotherapeutic regimens, might be employed as a relatively non-toxic and cost-effective means of enhancing survival in certain cancer types.

Investigation of lipid metabolism dysregulation and the effects on immune microenvironments in pan-cancer using multiple omics data

Background

Lipid metabolism reprogramming is a hallmark for tumor which contributes to tumorigenesis and progression, but the commonality and difference of lipid metabolism among pan-cancer is not fully investigated. Increasing evidences suggest that the alterations in tumor metabolism, including metabolite abundance and accumulation of metabolic products, lead to local immunosuppression in the tumor microenvironment. An integrated analysis of lipid metabolism in cancers from different tissues using multiple omics data may provide novel insight into the understanding of tumorigenesis and progression.

Results

Through systematic analysis of the multiple omics data from TCGA, we found that the most-widely altered lipid metabolism pathways in pan-cancer are fatty acid metabolism, arachidonic acid metabolism, cholesterol metabolism and PPAR signaling. Gene expression profiles of fatty acid metabolism show commonalities across pan-cancer, while the alteration in cholesterol metabolism and arachidonic acid metabolism differ with tissue origin, suggesting tissue specific lipid metabolism features in different tumor types. An integrated analysis of gene expression, DNA methylation and mutations revealed factors that regulate gene expression, including the differentially methylated sites and mutations of the lipid genes, as well as mutation and differential expression of the up-stream transcription factors for the lipid metabolism pathways. Correlation analysis of the proportion of immune cells in the tumor microenvironment and the expression of lipid metabolism genes revealed immune-related differentially expressed lipid metabolic genes, indicating the potential crosstalk between lipid metabolism and immune response. Genes related to lipid metabolism and immune response that are associated with poor prognosis were discovered including HMGCS2, GPX2 and CD36, which may provide clues for tumor biomarkers or therapeutic targets.

Conclusions

Our study provides an integrated analysis of lipid metabolism in pan-cancer, highlights the perturbation of key metabolism processes in tumorigenesis and clarificates the regulation mechanism of abnormal lipid metabolism and effects of lipid metabolism on tumor immune microenvironment. This study also provides new clues for biomarkers or therapeutic targets of lipid metabolism in tumors.

Electronic supplementary material

The online version of this article (10.1186/s12859-019-2734-4) contains supplementary material, which is available to authorized users.

CircRNA‑0044073 is upregulated in atherosclerosis and increases the proliferation and invasion of cells by targeting miR‑107

Circular RNAs (circRNAs) are endogenous non‑coding RNAs implicated in atherosclerosis. The aim of the present study was to explore the function of circRNA‑0044073 in atherosclerosis. Reverse transcription quantitative polymerase chain reaction assays were used to measure the expression levels of circRNA‑0044073, microRNA (miRNA/miR)‑107, janus kinase 1 (JAK1), signal transducer and activator of transcription 3 (STAT3), B‑cell lymphoma 2 (Bcl‑2) and v‑myc avian myelocytomatosis viral oncogene homolog (c‑myc) in in blood cells from patients with atherosclerosis. RNA pull‑down and luciferase reporter assays were then used to determine the association between circRNA and miR expression, and miR and gene expression, respectively. Matrigel invasion assay and flow cytometry were used to analyze cell invasion and cell cycle. Western blot analysis and ELISA were used to evaluate the expression levels of proteins. It was identified that the expression of circRNA‑0044073 was upregulated and the expression of miR‑107 was downregulated in atherosclerotic blood cells. Overexpression of circRNA‑0044073 promoted the proliferation of human vascular smooth muscle cells (HUVSMCs) and human vascular endothelial cells (HUVECs), while overexpression of miR‑107 inhibited their proliferation. In addition, circRNA‑0044073 suppressed the levels of miR‑107 via a sponge mechanism. Lipopolysaccharide (LPS) affected the proliferation of HUVSMCs and HUVECs, and also resulted in changes in circRNA‑0044073 expression levels. CircRNA‑0044073 promoted the proliferation and invasion of HUVSMCs and HUVECs in spite of the opposite effect observed with LPS treatment. The JAK/STAT signaling pathway was activated in patients with atherosclerosis. CircRNA‑0044073 favored the activation of the JAK/STAT signaling pathway and inflammation in HUVSMCs and HUVECs. These data indicate that circRNA‑0044073 is upregulated in atherosclerosis and promotes the proliferation and invasion of cells by targeting miR‑107 and activating the JAK/STAT signaling pathway, potentially offering a target for novel treatment strategies against atherosclerosis.

Inactivation of the Ras/MAPK/PPARγ signaling axis alleviates diabetic mellitus-induced erectile dysfunction through suppression of corpus cavernosal endothelial cell apoptosis by inhibiting HMGCS2 expression

PURPOSE

Diabetic mellitus-induced erectile dysfunction (DMED) represents a significant complication associated with diabetes mellitus (DM) that greatly affects human life quality. Various reports have highlighted the involvement of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) in the regulation of mitochondrial fatty acid oxidation, which has also been linked with DM. Through bioinformatics analysis, HMGCS2 was determined to be a novel target among DM patients suffering from erectile dysfunction (ED), and enriched in the Ras/ERK/PPAR signaling axis. Owing to the fact that the key mechanism HMGCS2 involved in DM remains largely unknown, we set out to investigate the role of the Ras/MAPK/PPARγ signaling axis and HMGCS2 in the corpus cavernosal endothelial cells (CCECs) of rats with DMED.

METHODS

Firstly, bioinformatics analysis was used to screen out differentially expressed genes in DMED. Then, to investigate the influence of the Ras/MAPK/PPARγ signaling axis and HMGCS2 on DMED, a rat model of DMED was established and injected with Simvastatin and si-Hmgcs2. The individual expression patterns of Ras, MAPK, PPARγ and HMGCS2 were determined by RT-qPCR, immunohistochemistry and western blot analysis methods. Afterwards, to investigate the mechanism of Ras/MAPK/PPARγ signaling axis and HMGCS2, CCECs were isolated from DMED rats and transfected with agonists and inhibitors of the Ras/MAPK/PPARγ signaling axis and siRNA of HMGCS2, with their respective functions in apoptosis and impairment of CCECs evaluated using TUNEL staining and flow cytometry.

RESULTS

Microarray analysis and KEGG pathway enrichment analysis revealed that Ras/ERK/PPAR signaling axis mediated HMGCS2 in DMED. Among the DMED rats, the Ras/MAPK/PPAR signaling axis was also activated while the expression of HMGCS2 was upregulated. The activation of Ras was determined to be capable of upregulating ERK expression which resulted in the inhibition of the transcription of PPARγ and subsequent upregulation of HMGCS2 expression. The inhibited activation of the Ras/ERK/PPAR signaling axis and silencing HMGCS2 were observed to provide an alleviatory effect on the injury of DMED while acting to inhibit the apoptosis of CCECs.

CONCLUSION

Collectively, the key findings suggested that suppression of the Ras/MAPK/PPARγ signaling axis could downregulate expression of HMGCS2, so as to alleviate DMED. This study defines the potential treatment for DMED through inhibition of the Ras/MAPK/PPARγ signaling axis and silencing HMGCS2.

miRmapper: A Tool for Interpretation of miRNA⁻mRNA Interaction Networks

It is estimated that 30% of all genes in the mammalian cells are regulated by microRNA (miRNAs). The most relevant miRNAs in a cellular context are not necessarily those with the greatest change in expression levels between healthy and diseased tissue. Differentially expressed (DE) miRNAs that modulate a large number of messenger RNA (mRNA) transcripts ultimately have a greater influence in determining phenotypic outcomes and are more important in a global biological context than miRNAs that modulate just a few mRNA transcripts. Here, we describe the development of a tool, “miRmapper”, which identifies the most dominant miRNAs in a miRNA–mRNA network and recognizes similarities between miRNAs based on commonly regulated mRNAs. Using a list of miRNA–target gene interactions and a list of DE transcripts, miRmapper provides several outputs: (1) an adjacency matrix that is used to calculate miRNA similarity utilizing the Jaccard distance; (2) a dendrogram and (3) an identity heatmap displaying miRNA clusters based on their effect on mRNA expression; (4) a miRNA impact table and (5) a barplot that provides a visual illustration of this impact. We tested this tool using nonmetastatic and metastatic bladder cancer cell lines and demonstrated that the most relevant miRNAs in a cellular context are not necessarily those with the greatest fold change. Additionally, by exploiting the Jaccard distance, we unraveled novel cooperative interactions between miRNAs from independent families in regulating common target mRNAs; i.e., five of the top 10 miRNAs act in synergy.

The Role of MicroRNAs in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers, leading to the second cancer-related death in the global. Although the treatment of HCC has greatly improved over the past few decades, the survival rate of patients is still quite low. Thus, it is urgent to explore new therapies, especially seek for more accurate biomarkers for early diagnosis, treatment and prognosis in HCC. MicroRNAs (miRNAs), small noncoding RNAs, are pivotal participants and regulators in the development and progression of HCC. Great progress has been made in the studies of miRNAs in HCC. The key regulatory mechanisms of miRNAs include proliferation, apoptosis, invasion, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, drug resistance and autophagy in HCC. And exosomal miRNAs also play important roles in proliferation, invasion, metastasis, and drug resistance in HCC by regulating gene expression in the target cells. In addition, some miRNAs, including exosomal miRNAs, can be as potential diagnostic and prediction markers in HCC. This review summarizes the latest researches development of miRNAs in HCC in recent years.

Pleiotropic functions of miR107 in cancer networks

MicroRNAs are short regulatory RNAs that posttranscriptionally modulate gene expression and thus play crucial roles in controlling cancer-onset, growth, and progression processes. miR107, a highly conserved microRNA that maps to intron 5 of the PANK1 gene, contributes to the regulation of normal and tumor biological processes. Studies have reported that miR107 has oncogenic or tumor-suppressor functions in different human tumors. The pleiotropic functions of miR107 in various cancers are achieved via its targeting different genes that are involved in tumor proliferation, invasiveness, metastasis, angiogenesis, and chemotherapy-response pathways. The carcinogenicity or cancer-suppressor effects of miR107 occur in a tissue- and cell-specific manner, and the expression level of miR107 can be affected by various factors, including epigenetic and genetic factors, treatment exposure, and daily diet. A comprehensive analysis of the current literature suggests that miR107 functions as a central element in the regulation of cancer networks and can be used as a potential diagnostic and prognostic biomarker and drug target for therapeutic intervention.

Identification of genes that predict the biochemical recurrence of prostate cancer

Prostate cancer (PCa) is one of the most prevalent cancer types in men. Biochemical recurrence continues to occur in a large proportion of patients after radical prostatectomy. Thus, prognostic biomarkers are required to determine which treatment is suitable. In the present study, RNA-sequencing gene expression data from The Cancer Genome Atlas was used in order to develop a risk-score staging system based on the expression of eight genes. Cox multivariate regression was used to predict the outcome of patients with PCa. The biomedical recurrence-free survival of patients with low-risk scores was significantly longer compared with patients with high-risk scores (P=5×10⁻⁷). This result was further validated using another dataset, GSE70769, from the National Center for Biotechnology Information. The prognostic values of other clinical information and risk scores were evaluated for 5-year biochemical recurrence. The prognostic value of the risk score was determined using an area under curve value of 0.819, predicting the 5-year biochemical recurrence of patients with PCa. The risk score was identified to be significantly associated with primary tumor stage (P<0.01), Gleason score (P<0.01), and lymph node invasion (P<0.05), but was independent of age. Cox multivariate regression revealed that the risk score was an indicator for prediction of biochemical recurrence. Thus, the risk score is a valuable and robust indicator for predicting the biochemical recurrence of patients with PCa.