SNHG1 knockdown upregulates miR-376a and downregulates FOXK1/Snail axis to prevent tumor growth and metastasis in HCC

LncRNA SNHG1: A novel biomarker and therapeutic target in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality globally. Increasing evidence suggests that long non-coding RNAs play a critical role in cancer development, with the small nucleolar RNA host gene family being a key participant in multiple types of carcinogenesis, including HCC. Small nucleolar RNA host gene 1 (SNHG1) is a significant member of the SNHG family. SNHG1 expression consistently increases in various HCC-associated processes, such as cell proliferation, apoptosis, angiogenesis, migration, invasion, and treatment resistance. Higher SNHG1 expression levels predict worse prognosis by positively correlating with clinicopathological features, including larger tumour size, poor differentiation, and advanced stages in patients with HCC. Nevertheless, the precise role of SNHG1 in the initiation and progression of HCC remains unclear. Therefore, this review aims to summarise the current investigations on the pathogenesis of SNHG1 in HCC, highlighting its potential as a molecular marker for early prediction and prognostic assessment. As a multifunctional modulator, SNHG1 is extensively involved in molecular signalling pathways in HCC progression and is valuable for therapeutic targeting.

The LncRNA lnc-POTEM-4:14 promotes HCC progression by interacting with FOXK1

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours of the digestive tract and poses a serious threat to human life. This study first analysed two GEO datasets (GSE166705 and GSE115018) to screen for differentially expressed lncRNAs between HCC and adjacent tissues. The lncRNA lnc-POTEM-4:14 was determined via a series of methods to be closely related to liver cancer. Further research was subsequently performed to investigate the role of the lncRNA lnc-POTEM-4:14 in the progression of HCC. The lncRNA lnc-POTEM-4:14 is localized primarily within the nucleus and is highly expressed in liver cancer tissues. We established lnc-POTEM-4:14 knockdown and overexpression cell lines to analyse the role of lnc-POTEM-4:14 in liver cancer through functional experiments such as qPCR and WB. We identified FOXK1 as an RNA-binding protein (RBP) of lnc-POTEM-4:14 that participates in MAPK signal activation and cell cycle progression by regulating the activation or expression levels of the downstream target protein TAB1 as a transcription factor. The restoration of FOXK1 can rescue the limited proliferation and increased apoptosis caused by lnc-POTEM-4:14 knockdown. Finally, we validated our hypothesis in a nude mouse tumour-bearing model. In conclusion, lnc-POTEM-4:14 affects the progression of HCC through the FOXK1/TAB1/NLK axis, suggesting that lnc-POTEM-4:14 has potential as a therapeutic target for treating this aggressive malignancy.

Genes of DLK1-DIO3 Locus and miR-379/656 Cluster is a Potential Diagnostic and Prognostic Marker in Patients With Hepatocellular Carcinoma: A Systems Biology Study

BACKGROUND

Hepatocellular carcinoma is the sixth most common malignancy reported globally. This highlights the need for reliable biomarkers that can be employed for diagnostic and prognostic applications. The present study aimed to classify and characterize the clinical potential of delta like non-canonical Notch ligand 1-type III iodothyronine deiodinase (DLK1-DIO3) and miR-379/656 cluster genes in hepatocellular carcinoma.

METHODS

We extensively studied the clinical potential of DLK1-DIO3 genes through a comprehensive systems biology approach and assessed the diagnostic and prognostic potential of the genes associated with the region. Additionally, we have predicted the gene targets of the miR-379/656 cluster associated with the locus and have identified the gene ontology, pathway, and disease associations.

RESULTS

We report this region as a potential biomarker for hepatocellular carcinoma. About thirty clustered miRNAs, a long-non-coding RNA, and two coding genes of the region were underexpressed in tumors. The receiver operating characteristic analysis identified 11 clustered miRNAs with diagnostic potential. Survival analyses identified maternally expressed gene 3 and the miR-379/656 cluster as prognostically significant. Further, the random forest model predicted that the miRNA cluster classifies patients according to Tumor, Node, Metastasis (TNM) staging. Furthermore, overrepresentation analysis identified several key pathways, molecular functions, and biological processes associated with the cluster gene targets.

CONCLUSION

Our study suggests that DLK1-DIO3 genes, miR-379/656 cluster, and its target gene network might be potential diagnostic and prognostic markers for hepatocellular carcinoma management and therapy.

High expression of small nucleolar host gene RNA may predict poor prognosis of Hepatocellular carcinoma, based on systematic reviews and meta-analyses

BACKGROUND

The prognosis of patients with hepatocellular cancer is substantially correlated with the abnormal expression of growing long non-coding RNA small nucleolar host gene RNA (SNHG) families in liver cancer tissues. This study aimed to examine the relationship between SNHG expression and liver cancer prognosis.

METHODS

After searching six internet databases, pertinent manuscripts were found based on inclusion and exclusion criteria. To determine whether SNHG expression levels affect liver cancer prognosis, raw data were collected and hazard ratios (HRs) and odds ratios (ORs) were calculated. The results were examined for potential publication bias using the sensitivity analysis and Beeg's test.

RESULTS

Most SNHG family members were up-regulated in liver cancer tissues. High SNHG expression predicts poor liver cancer outcomes of, including overall survival (OS) (HR: 1.697, 95% confidence interval [CI]: 1.373-2.021), especially SNHG5 (the HR of OS is 4.74, 95%CI range from 1.35 to 6.64), progression-free survival (HR: 1.85, 95% CI: 1.25-2.73), tumor, node, metastasis (TNM) stage (OR: 1.696, 95% CI: 1.436-2.005), lymph node metastasis (OR: 2.383, 95% CI: 1.098-5.173), and tumor size (OR: 1363, 95% CI: 1.165-1.595). The OS results were found to be reliable and robust, as indicated by the sensitivity analysis. Additionally, Beeg's test demonstrated the absence of any potential publication bias for each result.

CONCLUSION

In liver cancer tissues, most SNHGs are highly expressed, which may signal poor prognosis. SNHG has the potential to be an intriguing predictive marker and a prospective therapeutic target for liver cancer.

SNHG1: Redefining the Landscape of Hepatocellular Carcinoma through Long Noncoding RNAs

Hepatocellular carcinoma (HCC) represents a global health concern, ranking as the sixth most common malignancy worldwide and the third leading cause of cancer-related mortality. Despite advances in research, the diagnosis and prognosis of such malignancy remain challenging. Alpha-fetoprotein, the current serum biomarker used in the management of HCC, has limited sensitivity and specificity, making early detection and effective management more difficult. Thus, new management approaches in diagnosis and prognosis are needed to improve the outcome and survival of HCC patients. SNHG1 is a long noncoding RNA mainly expressed in the cell and cytoplasm of cells and is consistently upregulated in tissues and cell lines of HCC, where it acts as an important regulator of various processes: modulation of p53 activity, sponging of microRNAs with consequent upregulation of their target mRNAs, regulation of fatty acid, iron and glucose metabolism, and interaction with immune cells. The deregulation of these processes results in abnormal cell division, angiogenesis, and apoptosis, thus promoting various aspects of tumorigenesis, including proliferation, invasion, and migration of cells. Clinically, a higher expression of SNHG1 predicts poorer clinical outcomes by significantly correlating with bigger, less differentiated, and more aggressive tumors, more advanced disease stages, and lower overall survival in HCC patients. This article comprehensively summarizes the current understanding of the multifaceted roles of SNHG1 in the pathogenesis of HCC, while also highlighting its clinicopathological correlations, therefore concluding that it has potential as a biomarker in HCC diagnosis and prognosis.

Functional role of lncRNAs in gastrointestinal malignancies: the peculiar case of small nucleolar RNA host gene family

Long noncoding RNAs (lncRNAs) play crucial roles in normal physiology and are often de-regulated in disease states such as cancer. Recently, a class of lncRNAs referred to as the small nucleolar RNA host gene (SNHG) family have emerged as important players in tumourigenesis. Here, we discuss new findings describing the role of SNHGs in gastrointestinal tumours and summarize the three main functions by which these lncRNAs promote carcinogenesis, namely: competing with endogenous RNAs, modulating protein function, and regulating epigenetic marking. Furthermore, we discuss how SNHGs participate in different hallmarks of cancer, and how this class of lncRNAs may serve as potential biomarkers in cancer diagnosis and therapy.

Long noncoding RNA small nucleolar RNA host genes as prognostic molecular biomarkers in hepatocellular carcinoma: A meta-analysis

BACKGROUND

Recently, increasing data have suggested that the lncRNA small nucleolar RNA host genes (SNHGs) were aberrantly expressed in hepatocellular carcinoma (HCC), but the association between the prognosis of HCC and their expression remained unclear. The purpose of this meta-analysis was to determine the prognostic significance of lncRNA SNHGs in HCC.

METHODS

We systematically searched Embase, Web of Science, PubMed, and Cochrane Library for eligible articles published up to February 2024. The prognostic significance of SNHGs in HCC was evaluated by hazard ratios (HRs) and 95% confidence intervals (CIs). Odds ratios (ORs) were used to assess the clinicopathological features of SNHGs.

RESULTS

This analysis comprised a total of 25 studies covering 2314 patients with HCC. The findings demonstrated that over-expressed SNHGs were associated with larger tumor size, multiple tumor numbers, poor histologic grade, earlier lymphatic metastasis, vein invasion, advanced tumor stage, portal vein tumor thrombosis (PVTT), and higher alpha-fetoprotein (AFP) level, but not with hepatitis B virus (HBV) infection, and cirrhosis. In terms of prognosis, patients with higher SNHG expression were more likely to have shorter overall survival (OS), relapse-free survival (RFS), and disease-free survival (DFS).

CONCLUSIONS

In conclusion, upregulation of SNHGs expression correlates with shorter OS, RFS, DFS, tumor size and numbers, histologic grade, lymphatic metastasis, vein invasion, tumor stage, PVTT, and AFP level, suggesting that SNHGs may serve as prognostic biomarkers in HCC.

lncRNA SNHG9 enhances liver cancer stem cell self-renewal and tumorigenicity by negatively regulating PTEN expression via recruiting EZH2

Liver cancer stem cell (CSC) self-renewal and tumorigenesis are important causes of hepatocellular carcinoma (HCC) recurrence. We purposed to investigate the function of long noncoding RNA small nucleolar RNA host gene 9 (SNHG9) in liver CSC self-renewal and tumorigenesis in this study. Flow cytometry was carried out to separate CD133+ Populations and CD133- Populations from HCC cell lines. A combination of CD133+ cells and Matrigel matrix was subcutaneously injected to create the NOD-SCID mouse xenograft tumor model. Colony formation test and spheroids formation assay were carried out to clarify the impact of SNHG9 on the self-renewal of liver CSCs. RNA immunoprecipitation, RNA-pull down, and chromatin immunoprecipitation were performed on CD133+ cells to elucidate the mechanism of SNHG9 regulating PTEN expression. We found that SNHG9 was highly expressed in HCC clinical samples, HCC cells, and CD133+ cells. In vitro, interference with SNHG9 prevented the formation of colonies and spheroids in liver CSC cells and primary HCC cells. In vivo, interference with SNHG9 reduced the tumor volume and weight. SNHG9 could bind to EZH2, and SNHG9 interference suppressed EZH2 recruitment and H3K27me3 levels in the PTEN promoter region. In addition, SNHG9 inhibition promoted PTEN expression while having little impact on EZH2 levels. Interference with SNHG9 inhibited liver CSC self-renewal and tumorigenesis by up-regulating PTEN levels. In conclusion, by binding to EZH2, SNHG9 down-regulated PTEN levels, promoting liver CSC self-renewal and tumor formation, and exacerbating HCC progression.

MicroRNAs as the Critical Regulators of Forkhead Box Protein Family in Pancreatic, Thyroid, and Liver Cancers

The metabolism of human body is mainly regulated by the pancreas, liver, and thyroid using the hormones or exocrine secretions that affect the metabolic processes from food digestion to intracellular metabolism. Therefore, metabolic organ disorders have wide clinical symptoms that severely affect the quality of patient's life. The pancreatic, liver, and thyroid cancers as the main malignancies of the metabolic system have always been considered as one of the serious health challenges worldwide. Despite the novel therapeutic modalities, there are still significant high mortality and recurrence rates, especially in liver and pancreatic cancer patients which are mainly related to the late diagnosis. Therefore, it is required to assess the molecular bases of tumor progressions to introduce novel early detection and therapeutic markers in these malignancies. Forkhead box (FOX) protein family is a group of transcription factors that have pivotal roles in regulation of cell proliferation, migration, and apoptosis. They function as oncogene or tumor suppressor during tumor progression. MicroRNAs (miRNAs) are also involved in regulation of cellular processes. Therefore, in the present review, we discussed the role of miRNAs during pancreatic, thyroid, and liver tumor progressions through FOX regulation. It has been shown that miRNAs were mainly involved in tumor progression via FOXM and FOXO targeting. This review paves the way for the introduction of miR/FOX axis as an efficient early detection marker and therapeutic target in pancreatic, thyroid, and liver tumors.

The pivotal role of EMT-related noncoding RNAs regulatory axes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains a major health problem worldwide, being the leading cause of cancer-related deaths, with limited treatment options, especially in its advanced stages. Tumor resistance is closely associated with the activation of the EMT phenomenon and its reversal, being modulated by different molecules, including noncoding RNAs (ncRNAs). Noncoding RNAs have the potential to function as both tumor suppressors and oncogenic molecules, controlling the malignant potential of HCC cells. Basically, these molecules circulate in the tumor microenvironment, encapsulated in exosomes. Their impact on cell biology is more significant than originally expected, which makes related research rather complex. The temporal and spatial expression patterns, precise roles and mechanisms of specific ncRNAs encapsulated in exosomes remain primarily unknown in different stages of the disease. This review aims to highlight the recent advances in ncRNAs related to EMT and classifies the described mechanism as direct and indirect, for a better summarization. Moreover, we provide an overview of current research on the role of ncRNAs in several drug resistance-related pathways, including the emergence of resistance to sorafenib, doxorubicin, cisplatin and paclitaxel therapy. Nevertheless, we comprehensively discuss the underlying regulatory mechanisms of exosomal ncRNAs in EMT-HCC via intercellular communication pathways.

LncRNA SNHG1: role in tumorigenesis of multiple human cancers

Small nucleolar RNA host gene 1 (SNHG1) is an important member of the SNHG family. This family is composed of a group of host genes that can be processed into small nucleolar RNAs and play important biological functions. In an oncogenic role, the SNHG1 expression is increased in various cancers, which has immense application prospects in the diagnosis, treatment, and prognosis of malignant tumors. In this review, we have summarized the role and molecular mechanism of SNHG1 in the development of various cancers. In addition, we have emphasized the clinical significance of SNHG1 in cancers in our article. This molecule is expected to be a new marker for potential usage in the diagnosis, prognosis, and treatment of cancer.

FOXK1 regulates malignant progression and radiosensitivity through direct transcriptional activation of CDC25A and CDK4 in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a serious malignancy with poor prognosis, necessitating identification of oncogenic mechanisms for novel therapeutic strategies. Recent studies have highlighted the significance of the transcription factor forkhead box K1 (FOXK1) in diverse biological processes and carcinogenesis of multiple malignancies, including ESCC. However, the molecular pathways underlying FOXK1's role in ESCC progression are not fully understood, and its potential role in radiosensitivity remains unclear. Here, we aimed to elucidate the function of FOXK1 in ESCC and explore the underlying mechanisms. Elevated FOXK1 expression levels were found in ESCC cells and tissues, positively correlated with TNM stage, invasion depth, and lymph node metastasis. FOXK1 markedly enhanced the proliferative, migratory and invasive capacities of ESCC cells. Furthermore, silencing FOXK1 resulted in heightened radiosensitivity by impeding DNA damage repair, inducing G1 arrest, and promoting apoptosis. Subsequent studies demonstrated that FOXK1 directly bound to the promoter regions of CDC25A and CDK4, thereby activating their transcription in ESCC cells. Moreover, the biological effects mediated by FOXK1 overexpression could be reversed by knockdown of either CDC25A or CDK4. Collectively, FOXK1, along with its downstream target genes CDC25A and CDK4, may serve as a promising set of therapeutic and radiosensitizing targets for ESCC.

Bone marrow mesenchymal stem cell-derived exosomal microRNA-382 promotes osteogenesis in osteoblast via regulation of SLIT2

BACKGROUND

Osteoporosis (OP) is a systemic skeletal disorder with increased bone fragility. Human bone marrow mesenchymal stem cells (hBMSCs) have multi-lineage differentiation ability, which may play important roles in osteoporosis. In this study, we aim to investigate the role of hBMSC-derived miR-382 in osteogenic differentiation.

METHODS

The miRNA and mRNA expressions in peripheral blood monocytes between persons with high or low bone mineral density (BMD) were compared. Then we collected the hBMSC-secreted sEV and examined the dominant components. The over-expression of the miR-382 in MG63 cell and its progression of osteogenic differentiation were investigated by qRT-PCR, western blot and alizarin red staining. The interaction between miR-382 and SLIT2 was confirmed by dual-luciferase assay. The role of SLIT2 was also confirmed through up-regulation in MG63 cell, and the osteogenic differentiation-associated gene and protein were tested.

RESULTS

According to bioinformatic analysis, a series of differential expressed genes between persons with high or low BMD were compared. After internalization of hBMSC-sEV in MG63 cells, we observed that the ability of osteogenic differentiation was significantly enhanced. Similarly, after up-regulation of miR-382 in MG63 cells, osteogenic differentiation was also promoted. According to the dual-luciferase assay, the targeting function of miR-382 in SLIT2 was demonstrated. Moreover, the benefits of hBMSC-sEV in osteogenesis were abrogated through up-regulation of SLIT2.

CONCLUSION

Our study provided evidence that miR-382-contained hBMSC-sEV held great promise in osteogenic differentiation in MG63 cells after internalization by targeting SLIT2, which can be served as molecular targets to develop effective therapy.

H2S-mediated inhibition of RhoA/ROCK pathway and noncoding RNAs in ischemic stroke

Ischemic stroke is one of major causes of disability. In the pathological process of ischemic stroke, the up-regulation of Ras homolog gene family, member A (RhoA) and its downstream effector, Ras homolog gene family (Rho)-associated coiled coil-containing kinase (ROCK), contribute to the neuroinflammation, blood-brain barrier (BBB) dysfunction, neuronal apoptosis, axon growth inhibition and astrogliosis. Accumulating evidences have revealed that hydrogen sulphide (H₂S) could reduce brain injury in animal model of ischemic stroke via inhibiting the RhoA/ROCK pathway. Recently, noncoding RNAs (ncRNAs) such as circular RNAs (circRNAs), long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) have attracted much attention because of their essential role in adjusting gene expression both in physiological and pathological conditions. Numerous studies have uncovered the role of RhoA/ROCK pathway and ncRNAs in ischemic stroke. In this review, we focused on the role of H₂S, RhoA/ROCK pathway and ncRNAs in ischemic stroke and aimed to reveal new strategies for preventing and treating this devastating disease.

Oncogenic lncRNA BBOX1-AS1 promotes PHF8-mediated autophagy and elicits sorafenib resistance in hepatocellular carcinoma

Some long non-coding RNAs (lncRNAs) have been documented to be involved in cancer progression and anticancer drug resistance in hepatocellular carcinoma (HCC). Thus, approaches designed to target these genes may facilitate the development of promising strategies for treating HCC. Previously, we showed that lncRNA BBOX1-AS1 was highly expressed and played an oncogenic role in HCC. However, the potential functions and mechanisms through which BBOX1-AS1 regulates HCC progression and drug resistance remain unclear. This study revealed that BBOX1-AS1 could promote tumor progression, autophagy, and drug resistance by upregulating PHF8 in HCC cells. Mechanistically, BBOX1-AS1 enhanced the stability of PHF8 mRNA by targeting the PHF8 inhibitor miR-361-3p to regulate tumor progression and autophagy in HCC. The functional rescue experiments showed that PHF8 acted as a key factor in regulating the biological effects induced by BBOX1-AS1 and miR-361-3p in HCC, indicating that BBOX1-AS1 promotes tumor progression and sorafenib resistance by regulating miR-361-3p/PHF8. Finally, mouse tumor models and patient-derived organoid models were established to further confirm these findings. Taken together, the results demonstrate that BBOX1-AS1 promotes HCC progression and sorafenib resistance via the miR-361-3p/PHF8 axis.

miRNA-mRNA analysis of sheep adrenal glands reveals the network regulating reproduction

Background

The adrenal gland participates in the process of sheep reproduction. MicroRNAs (miRNAs), endogenous small noncoding RNAs, regulate gene expression at the posttranscriptional level. However, the miRNA-mRNA network profile of adrenal glands relating to reproduction in sheep is still not well-studied. As sheep with FecB^BB genotype show higher lambing number compare with the sheep with FecB⁺⁺ genotype. This research aims to compare gene expression by small RNA-seq in adrenal tissues at follicular (F) and luteal (L) phases in FecB^BB (MM) and FecB⁺⁺ (ww) sheep. After analysis of gene expression, significant differentially expressed microRNAs (DEMs) and corresponding target genes were identified.

Results

A total of 180 miRNAs were found in this study, of which 19 DEMs were expressed in the four comparison groups (MM_F_A vs. MM_L_A, MM_F_A vs. ww_F_A, MM_L_A vs. ww_L_A, ww_F_A vs. ww_L_A). Subsequently, 354 target genes of 19 DEMs were predicted by integrated analysis. Cluster analysis was performed by K_means_cluster, and the expression patterns of these DEMs were separated into four subclusters. Functional analysis of target genes was performed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The results indicated that the target genes were involved mainly in the Notch signaling pathway, signal transduction, cell communication, innate immune response and amino acid metabolism. Specifically, the Notch signaling pathway, biosynthetic process and metabolic process of pyrimidine nucleotide and amino acid metabolism appear to play key regulatory roles in the sheep fertility trait. Furthermore, miRNA-mRNA interaction networks were constructed by differentially expressed genes combined with our previous study of transcriptome data. The results showed that several key genes, including TDRD3, ANAPC7, CCNL2, BRD2 and MUT, were related to the transformation from the follicular phase to the luteal phase. PLAC8L1, NFAT5, DDX24 and MBD1 were related to the high fecundity of small tail Han sheep.

Conclusions

In this study, the miRNA transcriptome profile was identified, and miRNA-mRNA interaction networks were constructed in adrenal gland tissue of small tail Han sheep, the interaction between miR-370-3p and its targets were considered to play a major role in the reproduction regulation process. The results enriched the number of known miRNAs in adrenal glands and provided novel ideas and further information to demonstrate posttranscriptional regulation mechanisms at follicular and luteal phases in different genotypes of small tail Han sheep.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-022-01060-y.

Identification and validation of a fatty acid metabolism-related lncRNA signature as a predictor for prognosis and immunotherapy in patients with liver cancer

BACKGROUND

Fatty acid (FA) metabolism is considered the emerging cause of tumor development and metastasis, driving poor prognosis. Long non-coding RNAs (lncRNAs) are closely related to cancer progression and play important roles in FA metabolism. Thus, the discovery of FA metabolism-related lncRNA signatures to predict outcome and immunotherapy response is critical in improving the survival of patients with hepatocellular carcinoma (HCC).

METHODS

FA metabolism scores and a FA metabolism-related lncRNA signature were constructed using a single-sample gene set enrichment analysis based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. "ConsensusClusterPlus" was used to screen molecular subtypes. Chi-squared test and Fisher's exact test were applied to explore the relationship between clinical, genomic mutation characteristics and subtypes. Transcription factor (TF) activity scores, cellular distributions, immune cell infiltration, and immunotherapy response were employed to investigate the functions of FA metabolism-related lncRNA signatures. FA metabolism microarray and western blot were performed to detect the biological function of candidate lncRNAs.

RESULTS

A total of 70 lncRNAs that highly correlated with FA metabolism scores in two cohorts were used to construct two distinct clusters. Patients in cluster 2 had lower FA metabolism scores and worse survival than those in cluster 1. Patients in cluster 2 exhibited a high frequency of DNA damage, gene mutations, oncogenic signaling such as epithelial-to-mesenchymal transition, and a high degree of immune cell infiltration. Moreover, the lncRNA signature could predict the effects of immunotherapy in patients with HCC. Furthermore, three lncRNAs (SNHG1, LINC00261, and SNHG7) were identified that were highly correlated with FA metabolism. Additionally, SNHG1 and SNHG7 were found to regulate various FA metabolism-related genes and ferroptosis-related genes in vitro experiments. GSEA analysis revealed that SNHG1 and SNHG7 promote fatty acid beta-oxidation. SNHG1 and SNHG7 silencing dramatically reduced lipid droplets in HCC cells. Many immune-infiltration genes and TFs were overexpressed in HCC tissues with SNHG1 and SNHG7 high expression.

CONCLUSIONS

A novel molecular model of FA metabolism-related lncRNAs was developed, which has significantly prognostic potential in HCC diagnosis and aids in clinical decision making.

Long Noncoding RNAs and Circular RNAs Regulate AKT and Its Effectors to Control Cell Functions of Cancer Cells

AKT serine-threonine kinase (AKT) and its effectors are essential for maintaining cell proliferation, apoptosis, autophagy, endoplasmic reticulum (ER) stress, mitochondrial morphogenesis (fission/fusion), ferroptosis, necroptosis, DNA damage response (damage and repair), senescence, and migration of cancer cells. Several lncRNAs and circRNAs also regulate the expression of these functions by numerous pathways. However, the impact on cell functions by lncRNAs and circRNAs regulating AKT and its effectors is poorly understood. This review provides comprehensive information about the relationship of lncRNAs and circRNAs with AKT on the cell functions of cancer cells. the roles of several lncRNAs and circRNAs acting on AKT effectors, such as FOXO, mTORC1/2, S6K1/2, 4EBP1, SREBP, and HIF are explored. To further validate the relationship between AKT, AKT effectors, lncRNAs, and circRNAs, more predicted AKT- and AKT effector-targeting lncRNAs and circRNAs were retrieved from the LncTarD and circBase databases. Consistently, using an in-depth literature survey, these AKT- and AKT effector-targeting database lncRNAs and circRNAs were related to cell functions. Therefore, some lncRNAs and circRNAs can regulate several cell functions through modulating AKT and AKT effectors. This review provides insights into a comprehensive network of AKT and AKT effectors connecting to lncRNAs and circRNAs in the regulation of cancer cell functions.

Suppression of Long Noncoding RNA SNHG1 Inhibits the Development of Hypopharyngeal Squamous Cell Carcinoma via Increasing PARP6 Expression

Purpose

This study aimed to explore the function and molecular mechanism of long noncoding RNA Small Nucleolar RNA Host Gene 1 (SNHG1) in the development of hypopharyngeal squamous cell carcinoma (HSCC).

Methods

Human HSCC cell line FaDu was used in this study. Cell viability and apoptosis were detected using CCK-8 assay and flow cytometry, respectively. Cell migration and invasion were measured by Transwell assay. The expression of PARP6, XRCC6, β-catenin, and EMT-related proteins (E-cadherin and N-cadherin) were determined using western blotting. Moreover, the regulatory relationship between SNHG1 and PARP6 was investigated. Furthermore, the effects of the SNHG1/PARP6 axis on tumorigenicity were explored in vivo.

Results

Suppression of SNHG1 suppressed the viability, migration, and invasion but promoted apoptosis of FaDu cells in vitro (P < 0.01). PARP6 is a target of SNHG1, which was upregulated by SNHG1 knockdown in FaDu cells (P < 0.01). SNHG1 suppression and RARP6 overexpression inhibited FaDu cell proliferation, migration, and invasion (P < 0.05). SNHG1 suppression and RARP6 overexpression also inhibited tumorigenicity of HSCC in vivo. Furthermore, the protein expression of E-cadherin was significantly increased and that of N-cadherin, β-catenin, and XRCC6 was dramatically decreased in HSCC after SNHG1 suppression or/and RARP6 overexpression both in vitro and in vivo (P < 0.01).

Conclusions

SNHG1 silencing inhibits HSCC malignant progression via upregulating PARP6. XRCC6/β-catenin/EMT axis may be a possible downstream mechanism of the SNHG1/PARP6 axis in HSCC. SNHG1/PARP6 can be used as a promising target for the treatment of HSCC.

LncRNA SNHG1 activates glycolysis to promote hepatocellular cancer progression through miR-326/PKM2 axis

AIMS

Hepatocellular cancer (HCC) is a lethal malignancy with extremely poor prognosis. Here, we attempted to investigate the role and underlying mechanism of SNHG1 in HCC progression.

METHODS

Combined with bioinformatics and experimental validation, we explored the clinical significance of SNHG1 in HCC. CCK8, cell colony formation assay, and subcutaneous tumorigenesis experiments of nude mice were conducted to evaluate the pro-proliferative capacity of SNHG1. Glucose consumption and lactate production were measured to explore the regulatory role of SNHG1 in glycolysis. Nuclear-cytoplasmic separation, qRT-PCR and Western blot assays, chromatin immunoprecipitation, luciferase reporter and RNA immunoprecipitation assays were performed to investigate the molecular mechanisms of SNHG1 in HCC.

RESULTS

SNHG1 expression was dramatically increased in HCC and positively correlated with poor prognosis. It was E2F1 that bound to SNHG1 promoter region to activate SNHG1 transcription. Furthermore, SNHG1 served as a molecular sponge for miR-326 to sequester the interaction of miR-326 and PKM2, facilitating the expression of PKM2. Activating PKM2 expression was evidenced to be one of mechanisms of SNHG1 to promote glycolysis and proliferation of HCC cells.

CONCLUSION

E2F1-activated SNHG1 modulates miR-326/PKM2 axis to facilitate glycolysis and proliferation of HCC cells. Targeting SNHG1 could be a promising therapeutic option for HCC.

Long Noncoding RNA Small Nucleolar RNA Host gene 1 is not Only Overexpressed, But Also Correlates with Increased White Blood Cell Count, Deteriorate Induction Treatment Response and Poor Survival Profile in Adult Acute Myeloid Leukemia Patients

Objective

Long non-coding RNA small nucleolar RNA host gene 1 (lnc-SNHG1) is involved in leukemogenesis via mediating multiple pathways. The current study aimed to further explore its clinical role concerning disease risk, clinical features, and prognostication in patients with acute myeloid leukemia (AML).

Material and Methods

Generally, 161 adult AML patients, 50 disease controls (DC), and 50 healthy controls (HC) were enrolled; bone marrow mononuclear cells (BMMCs) were collected. Subsequently, a reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to measure the lnc-SNHG1 expression.

Results

Lnc-SNHG1 expression was higher in AML patients than that in DC and HC (both P<0.001), with a good value in distinguishing AML patients from DC and HC (area under the curve (AUC) of 0.726 and 0.884, respectively). Moreover, lnc-SNHG1 expression was positively associated with white blood cell (WBC) count (P=0.008) but not correlated with other clinical features such as cytogenetics, molecule-genetics, and risk stratifications, etc. (all P>0.05). Lnc-SNHG1 expression was associated with lower complete remission (CR) rate (P=0.001). In detail, patients with lnc-SNHG1 expression at quantile-4 had the worst CR rate compared to patients with lnc-SNHG1 expression at quantile-1, quantile-2, and quantile-3 (all P<0.05). Besides, lnc-SNHG1 expression was correlated with unsatisfied event-free survival (P<0.001) and overall survival (P=0.002), which were worst in patients with lnc-SNHG1 expression at quantile-4 compared with patients with lnc-SNHG1 expression at quantile-1, quantile-2 and quantile-3 (all P<0.05).

Conclusion

Lnc-SNHG1 overexpression is associated with elevated WBC, deteriorated induction treatment response, and poor survival profile in AML patients, which would further serve as a potential indicator for AML.

LncRNA SNHG1 promotes renal cell carcinoma progression through regulation of HMGA2 via sponging miR-103a

BACKGROUND

Long noncoding RNAs (LncRNAs) plays a vital role in tumorigenesis and development. The molecular mechanism of SNHG1 in renal cell carcinoma (RCC) has not been illustrated. The aim of this research was to explore the expression and function of LncRNA SNHG1 in RCC.

MATERIAL AND METHODS

The expression of SNHG1 in clinical tissues and RCC cell lines was detected. Luciferase reporter assay was performed to verify the correlation between SNHG1, miR-103a, and HMGA2. CCK-8 assay was performed to examine cell viability. Cell apoptosis was analyzed using flow cytometry. Cell invasion capacity was determined by Transwell assays. The protein level of HMGA2 was analyzed by Western blotting.

RESULTS

The expression of SNHG1 markedly increased in RCC tissues and cell lines. Subsequent studies identified SNHG1 as a miRNA sponge for miR-103a. In addition, SNHG1 knockdown and miR-103a overexpression significantly inhibited progression of RCC. miR-103a also regulated HMGA2 levels.

CONCLUSION

Our findings showed that SNHG1 was upregulated in RCC cells and tissues. SNHG1 promoted the malignant characteristics of RCC cells. Its regulatory effect may be regulation of HMGA2 by sponging miR-103a. Therefore, Our study facilitates the understanding of SNHG1 function in RCC.

N6-Methyladenosine-Related lncRNAs Are Anticipated Biomarkers for Sarcoma Patients

Background. Soft tissue sarcomas (STSs) are rare tumors and occur at any site in the body. Our goal was to identify a putative molecular mechanism for N6-methyladenosine (m6A) lncRNA alteration and to develop predictive biomarkers for sarcoma. Methods. The lncRNA levels were obtained from TCGA datasets. Pearson correlation analysis was used to select all the lncRNAs that are connected to m6A. An m6A-related lncRNA model was built using LASSO Cox regression. To assess the prognostic efficiency of the model and potential lncRNAs, we performed univariate survival analysis and receiver operating characteristic (ROC) analysis. We also performed enrichment analysis to evaluate the roles of the potential genes. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to confirm m6A-related lncRNA expression in tissues. Results. Following Pearson correlation analysis on TCGA datasets, we identified 78 m6A-related lncRNAs. Next, we used LASSO Cox regression analysis and identified 13 m6A-related lncRNAs as prognostic lncRNAs. After calculating risk scores, sarcoma patients were divided into high- and low-risk groups depending on the median of risk scores. We also found that these lncRNAs were immune associated via enrichment analysis. Conclusions. Here, we found that SNHG1, FIRRE, and YEATS2-AS1 could serve as biomarkers to predict overall survival of sarcoma patients, which provides a new insight into treatment of STS.

Comprehensive Analyses of MELK-Associated ceRNA Networks Reveal a Potential Biomarker for Predicting Poor Prognosis and Immunotherapy Efficacy in Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world with high morbidity and mortality. Identifying specific molecular markers that can predict HCC prognosis is extremely important. MELK has been reported to play key roles in several types of human cancers and predict poor prognosis. This study was aimed to explore the impact of MELK on HCC.

Methods: A pan-cancer analysis of MELK was conducted by The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) data. The prognosis of MELK in various cancers was analyzed in GEPIA. Then, a ceRNA network of MELK was constructed based on the comprehensive consideration of the expression analysis, the correlation analysis, and the survival analysis by R software. The correlation of MELK and immune cell infiltration was analyzed by TIMER and CIBERSORT. Then, the overall survival of differentially expressed immune cells was conducted. The correlation of MELK and immune checkpoints expression was analyzed by GEPIA.

Results: MELK was overexpressed in 14 types of human cancers, and its expression was significantly higher than that in both unmatched and paired normal samples in HCC. Higher MELK expression was correlated with poorer survival and advanced clinical stage, topography (T) stage, and histological grade. The univariate and multivariate Cox regression analyses showed that MELK was an independent risk factor for poor prognosis in HCC. Then, we constructed a ceRNA network consisting of MELK, miR-101-3p, and two lncRNAs (SNHG1 and SNHG6) after evaluating the expression and impact on prognosis in HCC of these RNAs. TIMER and CIBERSORT databases indicated that MELK was correlated with various immune cells including B cells, CD8+ T cells, CD4+ T cells, macrophage, neutrophil, and dendritic cells in HCC. Of them, B cells, CD4+ T cells, macrophage, and neutrophil were related to the prognosis of HCC. In addition, MELK was significantly positively correlated with the immune checkpoint genes.

Conclusions: MELK may be a novel potential biomarker for predicting prognosis and immunotherapy efficacy in patients with HCC. Our study may provide new molecular and therapeutic strategies for the treatment of HCC patients.

Identification of a Novel Survival-Related circRNA–miRNA–mRNA Regulatory Network Related to Immune Infiltration in Liver Hepatocellular Carcinoma

Increasing studies have reported that circular RNAs (circRNAs) play critical roles in tumorigenesis and cancer progression. However, the underlying regulatory mechanisms of circRNA-related competing endogenous RNA (ceRNA) in liver hepatocellular carcinoma (LIHC) are still unclear. In the present study, we discovered dysregulated circRNAs through Gene Expression Omnibus (GEO) analysis and validated the expression of the top seven circRNAs with upregulated expression by qRT–PCR and Sanger sequencing. Then, the Cancer-Specific CircRNA Database (CSCD) was used to predict the downstream miRNAs of seven circRNAs, and expression and survival analyses through The Cancer Genome Atlas (TCGA) were performed to identify the key miRNA in LIHC. Thereafter, the hsa_circ_0017264-hsa-miR-195–5p subnetwork was successfully constructed. Subsequently, we predicted downstream target genes of hsa-miR-195–5p with TargetScan, miRDB, and mirtarbase and overlapped them with differentially expressed mRNAs to obtain 21 target genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to predict the biological and functional roles of these target genes. Finally, with Pearson correlation and prognostic value analysis, a survival-related hsa_circ_0017264-hsa-miR-195-5p-CHEK1/CDC25A/FOXK1 axis was established. Gene set enrichment analysis (GSEA) was performed to determine the function of CHEK1/CDC25A/FOXK1 in the ceRNA network. Moreover, immune infiltration analysis revealed that the ceRNA network was markedly associated with the levels of multiple immune cell infiltrates, immune cell biomarkers and immune checkpoints. Overall, the hsa_circ_0017264-hsa-miR-195-5p-CHEK1/CDC25A/FOXK1 network might provide novel insights into the potential mechanisms underlying LIHC onset and progression.

SNHG1/miR-194-5p/MTFR1 Axis Promotes TGFβ1-Induced EMT, Migration and Invasion of Tongue Squamous Cell Carcinoma Cells

Tongue squamous cell carcinoma (TSCC) is a common malignancy with aggressive biological behaviors. Mitochondrial fission regulator 1 (MTFR1), is aberrantly expressed in head and neck squamous cell carcinoma (HNSC), but its role in TSCC remains unclear. We aimed to explore the role of MTFR1 in TSCC. The expression of long non-coding RNA small nucleolar RNA host gene 1 (SNHG1), microRNA-194-5p and MTFR1 in TSCC cells was measured by RT-qPCR. Luciferase reporter assay and RNA pull down assay were applied to confirm the binding capacity between miR-194-5p and SNHG1 (or MTFR1). TSCC cell invasion and migration were accessed by Transwell assays. The protein levels of MTFR1 and epithelial-mesenchymal transition (EMT) markers were examined by western blot. MTFR1 had high expression level in TSCC. MTFR1 knockdown inhibited transforming growth factor β1 (TGFβ1)-induced EMT, migration and invasion of TSCC cells in vitro. MiR-194-5p targeted MTFR1 and negatively regulated its expression. In addition, SNHG1 upregulated the expression of MTFR1 by binding with miR-194-5p. Importantly, SNHG1 promoted EMT, invasion and migration of TSCC cells by upregulating MTFR1. SNHG1/miR-194-5p/MTFR1 axis promotes TGFβ1-induced EMT, migration and invasion of cells in TSCC, which could be potential targets for treating TSCC patients.

miR-376a inhibits glioma proliferation and angiogenesis by regulating YAP1/VEGF signalling via targeting of SIRT1

BACKGROUND

Glioma is the most common cancer in the central nervous system. Previous studies have revealed that the miR-376 family is crucial in tumour development; however, its detailed mechanism in glioma is not clear.

METHODS

Cellular mRNA or protein levels of miR-376a, SIRT1, VEGF and YAP1 were detected via qRT-PCR or Western blotting. We analysed the proliferation, angiogenesis and migration abilities of glioma cell lines using colony formation, tube formation and Transwell assays. A luciferase assay was performed to determine whether miR-376a could recognize SIRT1 mRNA. Xenograft experiments were performed to analyse the tumorigenesis capacity of glioma cell lines in nude mice. The angiogenesis marker CD31 in xenograft tumours was detected via immunohistochemistry (IHC).

RESULTS

miR-376a expression was lower in glioma cells than in normal astrocytes. miR-376a mimic inhibited SIRT1, YAP1, and VEGF expression and suppressed the proliferation, migration and angiogenesis abilities of the glioma cell lines LN229 and A172, whereas miR-376a inhibitor exerted the opposite functions. In a luciferase assay, miR-376a inhibited the luciferase activity of WT-SIRT1. SIRT1 overexpression upregulated YAP1 and VEGF in glioma cells and promoted proliferation, migration and angiogenesis. Xenografts with ectopic miR-376a expression exhibited lower volumes and weights and a slower growth curve. Overexpression of miR-376a inhibited YAP1/VEGF signalling and angiogenesis by inhibiting SIRT1 in xenograft tissues.

CONCLUSION

miR-376a directly targets and inhibits SIRT1 in glioma cells. Downregulation of SIRT1 resulted in decreased YAP1 and VEGF signalling, which led to suppression of glioma cell proliferation, migration and angiogenesis.

The role of ceRNA-mediated diagnosis and therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide due to its high degree of malignancy, high incidence, and low survival rate. However, the underlying mechanisms of hepatocarcinogenesis remain unclear. Long non coding RNA (lncRNA) has been shown as a novel type of RNA. lncRNA by acting as ceRNA can participate in various biological processes of HCC cells, such as tumor cell proliferation, migration, invasion, apoptosis and drug resistance by regulating downstream target gene expression and cancer-related signaling pathways. Meanwhile, lncRNA can predict the efficacy of treatment strategies for HCC and serve as a potential target for the diagnosis and treatment of HCC. Therefore, lncRNA serving as ceRNA may become a vital candidate biomarker for clinical diagnosis and treatment. In this review, the epidemiology of HCC, including morbidity, mortality, regional distribution, risk factors, and current treatment advances, was briefly discussed, and some biological functions of lncRNA in HCC were summarized with emphasis on the molecular mechanism and clinical application of lncRNA-mediated ceRNA regulatory network in HCC. This paper can contribute to the better understanding of the mechanism of the influence of lncRNA-mediated ceRNA networks (ceRNETs) on HCC and provide directions and strategies for future studies.

Identification of Therapeutic Targets for the Selective Killing of HBV-Positive Hepatocytes

The hepatitis B virus (HBV) infection is a major risk factor for cirrhosis and hepatocellular carcinoma. Most infected individuals become lifelong carriers of HBV as the drugs currently used to treat the patients can only control the disease, thereby achieving functional cure (loss of the hepatitis B surface antigen) but not complete cure (elimination of infected hepatocytes). Therefore, we aimed to identify the target genes for the selective killing of HBV-positive hepatocytes to develop a novel therapy for the treatment of HBV infection. Our strategy was to recognize the conditionally essential genes that are essential for the survival of HBV-positive hepatocytes, but non-essential for the HBV-negative hepatocytes. Using microarray gene expression data curated from the Gene Expression Omnibus database and the known essential genes from the Online GEne Essentiality database, we used two approaches, comprising the random walk with restart algorithm and the support vector machine approach, to determine the potential targets for the selective killing of HBV-positive hepatocytes. The final candidate genes list obtained using these two approaches consisted of 36 target genes, which may be conditionally essential for the cell survival of HBV-positive hepatocytes; however, this requires further experimental validation. Therefore, the genes identified in this study can be used as potential drug targets to develop novel therapeutic strategies for the treatment of HBV, and may ultimately help in achieving the elusive goal of a complete cure for hepatitis B.