LncSNHG3/miR-139-5p/BMI1 axis regulates proliferation, migration, and invasion in hepatocellular carcinoma

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.

Potential Role of MAP3K14 in Hepatocellular Carcinoma: A Study Based on Comprehensive Bioinformatical Analysis and Validation

According to reports, MAP3K14 is considered an oncogene and is aberrantly expressed in various types of tumor cells. Its abnormal expression is closely associated with the occurrence and progression of various cancers. MAP3K14 also plays a significant role in the development of non-alcoholic steatohepatitis (NASH)-related hepatocellular carcinoma and its connection to tumor stem cells. The prognostic value of MAP3K14 in HCC, as well as its potential functions and roles, requires further elucidation. We evaluated the potential role of MAP3K14 in HCC based on data mining from a range of public databases. The bioinformatics analysis of TCGA, GEO, TIMER, cBioportal, Kaplan-Meier plotter, MethSurv, ENCORI and CellMiner databases was carried out. The expression of MAP3K14 protein in HCC was detected by immunohistochemical method. The mRNA and protein expression levels of MAP3K14 in tumor tissues were higher than those in normal tissues (p < 0.05). The expression of MAP3K14 was correlated with Pathologic T stage (p=0.026), Pathologic stage (p=0.032), Tumor status (p=0.024) and AFP (p=0.002). HCC patients with high expression of MAP3K14 had poor overall survival (OS), progression free survival (PFS) and recurrence free survival (RFS). Multivariate Cox regression analysis showed that the Pathologic stage (p < 0.001) and MAP3K14 expression levels (p < 0.05) is an independent prognostic factor affecting the survival of patients with liver cancer. GO/KEGG analysis suggested that key biological processes (PI3K-Akt signaling pathway) may be the mechanism promoting HCC development. In addition, MAP3K14 was significantly correlated with the infiltrating levels of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells (p < 0.05). MAP3K14 is up-regulated in HCC and is closely related to the prognosis of HCC patients. MAP3K14 may serve as a potential biomarker for poor prognosis of HCC.

Construction of a Novel Cuproptosis-Related ceRNA Network-SNHG3/miR-1306-5p/PDHA1 and Identification of SNHG3 as a Prognostic Biomarker in Hepatocellular Carcinoma

The crucial role of competitive endogenous RNA (ceRNA) in the malignant biological behavior of tumors has been certificated. Nevertheless, the detailed function and molecular mechanism of ceRNA associated with cuproptosis in hepatocellular carcinoma (HCC) remains dismal. In this study, we first constructed a protein-protein interaction network and identified the module with the highest degree of aggregation degree. DLAT and PDHA1 were screened out of the module after differential expression and survival analysis. Next, we reverse-predicted the upstream miRNA and lncRNA from mRNA (DLAT, PDHA1) and successfully established the ceRNA network-SNHG3/miR-1306-5p/PDHA1. SNHG3 was identified to be an independent prognostic biomarker based on the outcome of univariate and multivariate Cox analyses. Subsequently, we implemented methylation, immune infiltration, and drug sensitivity analysis to investigate the potential biological functions of SNHG3 in HCC. In addition, SNHG3 expression was upregulated in liver cancer cell lines. In vitro functional assay revealed that SNHG3 knockdown significantly attenuated proliferation, migration, and invasion of liver cancer cells. In summary, SNHG3 exhibited oncogenic characterization via sponging miR-1306-5p to regulate PDHA1, which might function as a promising prognostic indicator and a potential therapeutic target for HCC and shed new light on the molecular mechanism of HCC progression.

The role of BMI1 in endometrial cancer and other cancers

Endometrial cancer (EC) is the third leading gynecological malignancy, and its treatment remains challenging. B cell-specific Moloney murine leukemia virus integration site-1 (BMI1) is one of the core members of the polycomb group (PcG) family, which plays a promoting role in the occurrence and development of various tumors. Notably, BMI1 has been found to be frequently upregulated in endometrial cancer (EC) and promote the occurrence of EC through promoting epithelial-mesenchymal transition (EMT) and AKT/PI3K pathways. This review summarizes the structure and upstream regulatory mechanisms of BMI1 and its role in EC. In addition, we focused on the role of BMI1 in chemoradiotherapy resistance and summarized the current drugs that target BMI1.

A comprehensive review of the role of lncRNAs in gastric cancer (GC) pathogenesis, immune regulation, and their clinical applications

Gastric cancer (GC) is the fifth most common malignant tumor and the third leading cause of cancer-related deaths worldwide. Although numerous studies have been conducted on advanced GC, the molecular mechanisms behind it remain obscure. Long non-coding RNAs (lncRNAs) are a family of RNA transcripts capable of regulating target genes at transcriptional, post-transcriptional, and translational stages. They do this by modifying mRNAs, miRNAs, and proteins. These RNAs are critical regulators of many biological processes, including gene epigenetics, transcription, and post-transcriptional levels. This article highlights recent results on lncRNAs involved in drug resistance, proliferation, migration, angiogenesis, apoptosis, autophagy, and immune response in GC. The potential clinical implications of lncRNAs as biomarkers and therapeutic targets in GC are also discussed.

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

BACKGROUND

Hepatocellular carcinoma (HCC) is a common malignancy worldwide, and the mortality rate continues to rise each year. SMARCA4 expression has been associated with poor prognosis in various types of cancer; however, the specific mechanism of action of SMARCA4 in HCC needs to be fully elucidated.

AIM

To explore the specific mechanism of action of SMARCA4 in HCC.

METHODS

Herein, the expression level of SMARCA4 as well as its association with HCC prognosis were evaluated using transcriptome profiling and clinical data of 18 different types of cancer collected from The Cancer Genome Atlas database. Furthermore, SMARCA4-high and -low groups were identified. Thereafter, gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to identify the function of SMARCA4, followed by construction of a SMARCA4-specific competing endogenous RNA (ceRNA) network using starBase database. The role of SMARCA4 in immunotherapy and its association with immune cells were assessed using correlation analysis.

RESULTS

It was observed that SMARCA4 was overexpressed and negatively correlated with prognosis in HCC. Further, SMARCA4 expression was positively associated with tumor mutational burden, microsatellite stability, and immunotherapy efficacy. The SNHG3/THUMP3-AS1-miR-139-5p-SMARCA4 ceRNA network was established and could be assumed to serve as a stimulatory mechanism in HCC.

CONCLUSION

The findings of this study demonstrated that SMARCA4 plays a significant role in progression and immune infiltration in HCC. Moreover, a ceRNA network was detected, which was found to be correlated with poor prognosis in HCC. The findings of this study could contribute towards the identification of predictive markers for immunotherapy and a novel mechanism of action for HCC treatment.

LncRNA SNHG3 promoted cell proliferation, migration, and metastasis of esophageal squamous cell carcinoma via regulating miR-151a-3p/PFN2 axis

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignant tumor with a poor prognosis. The dysregulation of long non-coding RNAs (lncRNAs) is closely related to the tumorigenesis and progression of ESCC. However, the effects of lncRNA small nucleolar RNA host gene 3 (lncRNA SNHG3) in ESCC are still unclear. Therefore, a series of experiments methods, such as quantitative real-time polymerase chain reaction, function gain/loss experiments, western blots, and animal xenograft tumor model, were employed to explore the biological function and molecular mechanism of SNHG3 in ESCC. As results, we first reported that SNHG3 was significantly up-regulated in ESCC tissues and cells. SNHG3 knockdown obviously inhibited cell proliferation, migration, invasion, and promoted apoptosis. Mechanism analysis revealed that SNHG3 sponged miR-151a-3p to regulate PFN2. Inhibition of miR-151a-3p and overexpression of PFN2 attenuated the positive effect of SNHG3 knockdown on suppressing tumor progression. Furthermore, the anti-tumor effects of SNHG3 knockdown were also observed in vivo. In summary, our results indicated that SNHG3 knockdown suppressed tumor development via the miR-151a-3p/PFN2 axis, and targeting SNHG3 may provide a new opportunity for ESCC patients.

Systematic pan-cancer analysis on the expression and role of regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene 12

Regulator of chromatin condensation 1 (RCC1) is the major guanine nucleotide exchange factor of RAN GTPase, which plays a key role in various biological processes such as cell cycle and DNA damage repair. Small nucleolar RNA host gene 3 (SNHG3) and small nucleolar RNA host gene12 are long-stranded non-coding RNAs (lncRNAs) and are located on chromatin very close to the sequence of Regulator of chromatin condensation 1. Many studies have shown that they are aberrantly expressed in tumor tissues and can affect the proliferation and viability of cancer cells. Although the effects of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 on cellular activity have been reported, respectively, their overall analysis on the pan-cancer level has not been performed. Here, we performed a comprehensive analysis of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 in 33 cancers through the Cancer Genome Atlas and Gene Expression Database. The results showed that Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 were highly expressed in a variety of tumor tissues compared to normal tissues. The expression of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 in BRCA, LGG and LIHC was associated with TP53 mutations. In addition, Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 expression was closely associated with the prognosis of patients with multiple tumors. Immunocorrelation analysis indicated that Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 showed a correlation with multiple immune cell infiltration. The results of enrichment analysis suggested that Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 was involved in the regulation of cell cycle, apoptosis and other pathways. We found that these effects were mainly mediated by Regulator of chromatin condensation 1, while the trend of small nucleolar RNA host gene 3/small nucleolar RNA host gene12 regulation was also consistent with regulator of chromatin condensation 1. The important role played by Regulator of chromatin condensation 1 in tumor diseases was further corroborated by the study of adjacent lncRNAs.These findings provide new and comprehensive insights into the role of Regulator of chromatin condensation 1/small nucleolar RNA host gene 3/small nucleolar RNA host gene12 in tumor development and show their potential as clinical monitoring and therapy.

Oncogenic role and potential regulatory mechanism of topoisomerase IIα in a pan-cancer analysis

Topoisomerase IIα (TOP2A) plays an oncogenic role in multiple tumor types. However, no pan-cancer analysis about the function and the upstream molecular mechanism of TOP2A is available. For the first time, we analyzed potential oncogenic roles of TOP2A in 33 cancer types via The Cancer Genome Atlas (TCGA) database. Overexpression of TOP2A was existed in almost all cancer types, and related to poor prognosis and advanced pathological stages in most cases. Besides, the high frequency of TOP2A genetic alterations was observed in several cancer types, and related to prognosis in some cases. Moreover, we conduct upstream miRNAs and lncRNAs of TOP2A to establish ceRNA networks in kidney renal clear cell carcinoma (SNHG3-miR-139-5p), kidney renal papillary cell carcinoma (TMEM147-AS1/N4BP2L2-IT2/THUMPD3-AS1/ERICD/TTN-AS1/SH3BP5-AS1/THRB-IT1/SNHG3/NEAT1-miR-139-5p), liver hepatocellular carcinoma (SNHG3/THUMPD3-AS1/NUTM2B-AS1/NUTM2A-AS1-miR-139-5p and SNHG6/GSEC/SNHG1/SNHG14/LINC00265/MIR3142HG-miR-101-3p) and lung adenocarcinoma (TYMSOS/HELLPAR/SNHG1/GSEC/SNHG6-miR-101-3p). TOP2A expression was generally positively correlated with cancer associated fibroblasts, M0 and M1 macrophages in most cancer types. Furthermore, TOP2A was positively associated with expression of immune checkpoints (CD274, CTLA4, HAVCR2, LAG3, PDCD1 and TIGIT) in most cancer types. Our first TOP2A pan-cancer study contributes to understanding the prognostic roles, immunological roles and potential upstream molecular mechanism of TOP2A in different cancers.

Identification of m6A-Related lncRNA to Predict the Prognosis of Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide. In the past decades, HCC treatment has achieved great progress; however, the overall prognosis remains poor. Therefore, it is the need of the hour to identify new prognostic biomarkers which can advance our understanding related to the underlying molecular mechanism of adverse prognosis and apply them to clinical work in prognosis prediction. In the present study, data of 576 HCC patients and 292 normal control cases from TCGA and ICGC databases were enrolled to our bioinformatic analysis. SNHG1 and SNHG3 were identified as overlapping genes in TCGA and ICGC databases using Pearson correlation analysis and univariate Cox regression analysis. Further, we used the median of the SNHG1 and SNHG3 expression values as the cutoff values to define the HCC patient groups with high or low expression level. The subsequent analysis revealed that abnormal high expression of SNHG1 or SNHG3 affected the immune infiltration patterns and the crosstalk among immune cells. Moreover, high expression of SNHG1 or SNHG3 resulted in drug resistant to AKT inhibitor VII, bexarotene, bicalutamide, dasatinib, erlotinib, and gefitinib. In addition, lower tumor neoantigen burden was observed in high SNHG1 or SNHG3 group. Further, we found significant relation between the aberrant upregulation of SNHG1 and SNHG3 in tumor grade and stage. We established a nomogram to systematically predict the 5- and 8-year overall survival of liver cancer patients with good accuracy. Finally, the in vitro assays suggest that SNHG1 and SNHG3 promote the proliferative, migratory, and invasive abilities of HCC cells.

Prognostic Role and Potential Mechanisms of N6-methyladenosine-related Long Noncoding RNAs in Hepatocellular Carcinoma

BACKGROUND AND AIMS

Numerous studies have explored the important role of N6-methyladenosine (m⁶A) in cancer. Nonetheless, the interaction between m⁶A and long noncoding RNAs (lncRNAs) is poorly investigated. Herein, we systematically analyzed the role and prognostic value of m⁶A-related lncRNAs in hepatocellular carcinoma (HCC).

METHODS

The m⁶A-related lncRNAs were identified based on the correlation coefficients with m⁶A-related genes in HCC from The Cancer Genome Atlas. Subsequently, a novel risk score model was determined using the least absolute shrinkage and selection operator Cox regression analyses. Univariate and multivariate Cox analyses were used to identify independent prognostic factors for overall survival (OS) of HCC; thereafter, a prognostic nomogram was constructed.

RESULTS

A total of 259 lncRNAs showed significant correlations with m⁶A in HCC, while 29 lncRNAs had prognostic significance. Further, six critical m⁶A-related lncRNAs (NRAV, SNHG3, KDM4A-AS1, AC074117.1, AC025176.1, and AL031985.3) were screened out to construct a novel risk score model which classified HCC patients into high- and low-risk groups. Survival analyses revealed that patients in the high-risk group exhibited worse OS, both in the training and validation groups. The risk score was also identified as an independent prognostic factor of OS, and a nomogram was established and verified with superior prediction capacity. Besides, the risk score significantly correlated with the expression of immune checkpoint genes and immune subtypes.

CONCLUSIONS

These findings indicated the significant role of m⁶A-related lncRNAs in HCC and the potential application of the novel risk score model for prognostic prediction.

SNHG3 Affects Gastric Cancer Development by Regulating SEPT9 Methylation

Background

Gastric cancer (GC) is a common malignancy that can be formed by methylation-induced deactivation of tumor silencer genes, which is one of the key mechanisms of tumorigenesis. SEPT9 methylation, a symptomatic marker for tumors, can downregulate gene expression. Long noncoding RNA small nucleolar host gene 3 (lncRNA SNHG3) is a new type of lncRNA related to cancer. Our study investigated the mechanism of SNHG3 regulation of SEPT9 methylation and its effects on the growth, metastasis, and spread of gastric cancer cells.

Methods

Quantitative real-time PCR (qRT–PCR) was used to detect SNHG3 and miR-448 in gastric cancer, and a dual-luciferase experiment verified the effects of SNHG3, miR-448, and DNMT1. After abnormally expressing SNHG3, miR-448, and DNMT1 alone or together, methylation-specific PCR was performed to determine the methylation of SEPT9, Western blotting was performed to detect the expression of DNA methyltransferase 1 (DNMT1) and SEPT9, and Transwell, scratch, and CCK-8 assays were performed to reveal the invasion, migration, and cell growth of gastric cancer cells.

Results

We found that SNHG3 was upregulated in gastric cancer and that SNHG3 knockdown or miR-448 overexpression inhibited SEP9 methylation and therefore increased its expression, thereby inhibiting the growth, metastasis, and spread of gastric cancer cells.

Conclusion

Our study indicates that SNHG3 regulates SEPT9 methylation by targeting miR-448/DNMT1 and subsequently affecting the occurrence and development of gastric cancer.

An m6A-Related lncRNA Signature Predicts the Prognosis of Hepatocellular Carcinoma

Objective: The purpose of this study was to establish an N6-methylandenosine (m6A)-related long non-coding RNA (lncRNA) signature to predict the prognosis of hepatocellular carcinoma (HCC).

Methods: Pearson correlation analysis was used to identify m6A-related lncRNAs. We then performed univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) Cox regression analysis to construct an m6A-related lncRNA signature. Based on the cutoff value of the risk score determined by the X-title software, we divided the HCC patients into high -and low-risk groups. A time-dependent ROC curve was used to evaluate the predictive value of the model. Finally, we constructed a nomogram based on the m6A-related lncRNA signature.

Results: ZEB1-AS1, MIR210HG, BACE1-AS, and SNHG3 were identified to comprise an m6A-related lncRNA signature. These four lncRNAs were upregulated in HCC tissues compared to normal tissues. The prognosis of patients with HCC in the low-risk group was significantly longer than that in the high-risk group. The M6A-related lncRNA signature was significantly associated with clinicopathological features and was established as a risk factor for the prognosis of patients with HCC. The nomogram based on the m6A-related lncRNA signature had a good distinguishing ability and consistency.

Conclusion: We identified an m6A-related lncRNA signature and constructed a nomogram model to evaluate the prognosis of patients with HCC.

NLRP6-Dependent Pyroptosis-Related lncRNAs Predict the Prognosis of Hepatocellular Carcinoma

Pyroptosis, a novel pro-inflammatory type of programmed cell death, is involved in the tumorigenesis of various cancers. Recent findings have implicated long non-coding RNAs (lncRNAs) in the serial steps of cancer development. However, the expression and prognostic signatures of pyroptosis-related lncRNAs in hepatocellular carcinoma (HCC) remain largely unknown. Therefore, a pyroptosis-related lncRNA prognostic model was constructed for HCC. Thirty-four pyroptosis-related genes were obtained from previous reviews, and gene expression data were collected from The Cancer Genome Atlas (TCGA) database. Spearman's correlation test was used to identify potential pyroptosis-related lncRNAs. Cox and LASSO regression analyses were used to construct a prognostic model. Subsequently, receiver operating characteristic (ROC) curves were constructed to assess the model's predictive ability for the overall survival (OS) of HCC patients. CytoHubba was used to screen out the potential hub gene, whose expression was verified using clinical samples from HCC patients. Finally, nine pyroptosis-related differentially expressed lncRNAs in HCC were identified, and a prognostic model with four pyroptosis-related lncRNAs was constructed with an area under the ROC curve (AUC) of approximately 0.734. Single-sample gene set enrichment analysis and TCGA revealed different immune infiltration and immune checkpoints between the two risk groups. Moreover, these lncRNAs are closely related to the pyroptosis-related gene, NLRP6, which may be considered a hub gene. NLRP6 was lower-expressed in HCC samples, and patients with lower expression of NLRP6 had the longer OS. In conclusion, NLRP6-dependent pyroptosis-related lncRNAs play important roles in tumor immunity and may be potential predictors and therapeutic targets for HCC.

MiR-139-5p/ENAH Affects Progression of Hepatocellular Carcinoma Cells

This study aims to investigate the specific mechanism of miR-139-5p regulating hepatocellular carcinoma (HCC). Bioinformatic approaches was utilized to observe miR-139-5p level in HCC and unearth its target mRNA. Next, miR-139-5p and enabled homolog (ENAH) levels in HCC cell lines and normal liver cell line were evaluated with qRT-PCR. ENAH protein level was assessed by Western blot. The cell viability, migratory and invasive capacities of HepG2 cells was observed by cell functional assays. The binding of these two genes was proved through dual-luciferase method. Xenograft nude mouse model was prepared to identify the role of miR-139-5p in vivo. Poorly expressed miR-139-5p in HCC hindered the phenotypes of cancer cells. ENAH was at high level in HCC and it is a downstream target of miR-139-5p. Additionally, ENAH could reverse the suppressive impacts of miR-139-5p on HCC cell behaviors. Likewise, miR-139-5p was determined to perform tumor-suppressing function in vivo. MiR-139-5p hampered HCC cell processes by mediating ENAH, and miR-139-5p/ENAH is hopefully to be the possible target for HCC patients.

Long non-coding RNA small nucleolar RNA host genes: functions and mechanisms in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors of the digestive system, with a high degree of malignancy. Although treatment methods are constantly improving, the mortality of patients is still very high, and the small nucleolar RNA host gene (SNHG) plays an important role in the occurrence and development of cancer. It can activate downstream signaling molecules by acting on microRNA and microRNA target genes, promote the proliferation, invasion, and migration of HCC cells, and provide a new molecular target for the treatment of HCC. At present, the molecular mechanisms of HCC remain unclear. In this study, the mechanism and signaling pathway of SNHG in HCC are reviewed, which provides a theoretical basis for the clinical treatment of HCC.

MiR-139-5p Targeting CCNB1 Modulates Proliferation, Migration, Invasion and Cell Cycle in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is the most frequent histological subtype of non-small cell lung cancer. Cyclin B1 (CCNB1) is the vital initiator and controller of mitosis. Studies have indicated that CCNB1 overexpression is closely associated with cell proliferation and tumorigenesis in many cancers. Thus, discovery of molecular mechanism of CCNB1 in LUAD is conducive to developing new diagnostic or therapeutic targets for LUAD. We acquired mature miRNA and mRNA expression information of LUAD from TCGA database, as well as related clinical data. CCNB1 expression in normal and LUAD tissue was analyzed. Relationship between CCNB1 and patient's survival and clinical stage was analyzed. Upstream regulatory gene miRNA of CCNB1 was predicted. qRT-PCR and western blot examined expression levels of CCNB1 and miR-139-5p in cells. CCK-8 tested cell proliferation. Scratch healing and Transwell determined cell migration and invasion. Flow cytometry analyzed the cell cycle. Dual-luciferase verified targeting relationship between the two genes. Compared to controls, CCNB1 expression was prominently high in LUAD patient samples, and associated with advanced tumor stages and shorter overall survival. MiR-139-5p expressed an evidently negative correlation with CCNB1 and was predicted to target CCNB1. MiR-139-5p mimics reduced CCNB1 mRNA and protein expression, and suppressed luciferase activity in a target-specific manner, as confirmed by a control construct with a mutated miR-139-5p binding site. CCNB1 overexpression fostered progression of LUAD cells. Mechanistically, miR-139-5p might negatively regulate CCNB1 in LUAD, thereby suppressing cell proliferation, migration, invasion and cell cycle.

LncSNHG3 promotes hepatocellular carcinoma epithelial mesenchymal transition progression through the miR-152-3p/JAK1 pathway

BACKGROUND

The dysregulation of LncRNAs is related to the malignant progression of many cancers.

OBJECTIVE

The study aimed to investigate the expression and the biological role of LncSNHG3 in hepatocellular carcinoma (HCC).

METHODS

The TCGA data of the LncSNHG3 in HCC were analyzed. The expression in HCC cell lines was detected by qRT-PCR. Proliferation, migration, and invasion of HepG2 and Huh7 were examined by cell counting kit-8, colony formation, transwell assays, and wound healing assays. At the same time, the interactions among LncSNHG3, miR-152-3p, and JAK1 were confirmed by dual-luciferase reporter assay, RNA immunoprecipitation, subcellular distribution. Xenograft tumor-bearing mice models were used to measure the effect of LncSNHG3 on the growth of HCC in vivo. The apoptosis and epithelial mesenchymal transition (EMT)-associated proteins were checked by WB and IHC.

RESULTS

LncSNHG3 was overexpressed in HCC tissues and cell lines. In addition, it is correlated with the tumor stage and survival time of HCC patients. Down-regulated LncSNHG3 could significantly suppress the EMT progression of HCC in vivo and in vitro. LncSNHG3 could promote the JAK1 expression by sponging miR-152-3p.

CONCLUSIONS

LncSNHG3 acted as an oncogene and promoted the EMT procession in HCC by binding miR-152-3p and promoting JAK1 expression. Predictably, LncSNHG3 was used as a potential marker and will be used as a novel therapy target for HCC in the future.

Development and Validation of a Prognostic Signature Associated With Tumor Microenvironment Based on Autophagy-Related lncRNA Analysis in Hepatocellular Carcinoma

Objective: The present study aimed to establish a prognostic signature based on the autophagy-related long non-coding RNAs (lncRNAs) analysis in patients with hepatocellular carcinoma (HCC).

Methods: Patients with HCC from The Cancer Genome Atlas (TCGA) were taken as the training cohort, and patients from the International Cancer Genome Consortium (ICGC) were treated as the validation cohort. Autophagy-related lncRNAs were obtained via a co-expression network analysis. According to univariate and multivariate analyses, a multigene prognostic signature was constructed in the training cohort. The predictive power of the signature was confirmed in both cohorts. The detailed functions were investigated using functional analysis. The single-sample gene set enrichment analysis (ssGSEA) score was used to evaluate the tumor microenvironment. The expression levels of immunotherapy and targeted therapy targets between the two risk groups were compared. Finally, a nomogram was constructed by integrating clinicopathological parameters with independently predictive value and the risk score.

Results: Four autophagy-related lncRNAs were identified to establish a prognostic signature, which separated patients into high- and low-risk groups. Survival analysis showed that patients in the high-risk group had a shorter survival time in both cohorts. A time-independent receiver-operating characteristic (ROC) curve and principal component analysis (PCA) confirmed that the prognostic signature had a robust predictive power and reliability in both cohorts. Functional analysis indicated that the expressed genes in the high-risk group are mainly enriched in autophagy- and cancer-related pathways. ssGSEA revealed that the different risk groups were associated with the tumor microenvironment. Moreover, the different risk groups had positive correlations with the expressions of specific mutant genes. Multivariate analysis showed that the risk score also exhibited excellent predictive power irrespective of clinicopathological characteristics in both cohorts. A nomogram was established. The nomogram showed good discrimination, with Harrell's concordance index (C-index) of 0.739 and good calibration.

Conclusion: The four autophagy-related lncRNAs could be used as biological biomarkers and therapeutic targets. The prognostic signature and nomogram might aid clinicians in individual treatment optimization and clinical decision-making for patients with HCC.

Construction of a ceRNA network and a genomic-clinicopathologic nomogram to predict survival for HBV-related HCC

Some lncRNA-associated competing endogenous RNAs (ceRNAs) are considered as potential biomarkers for targeted therapies and prognosis in human cancer. In our present study, we aimed to construct a ceRNA network and establish a genomic-clinicopathologic nomogram to provide insights into the molecular mechanisms and predict survival for HBV-related HCC. The Cancer Genome Atlas (TCGA) database was applied to collect the data of LIHC RNA-seq dataset and miRNA-seq dataset as well as the clinicopathological information. Identification of differentially expressed RNAs (mRNAs, lncRNAs, and miRNAs) between HBV-related HCC samples and normal samples was conducted using Limma package in R. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was used for performing the functional enrichment analysis of differentially expressed mRNAs. The ceRNA network was carried out using Cytoscape. The LASSO-penalized Cox regression analysis was implemented to identify HCC-related lncRNAs, and the multivariate Cox regression analysis was conducted for the establishment of a genomic-clinicopathology nomogram. A total of 1859 DEmRNAs, 113 DElncRNAs, and 89 DEmiRNAs were screened out etween HBV-related HCC samples and normal samples. A ceRNA network including 44 DEmRNAs, 7 DElncRNAs, and 20 DEmiRNAs was constructed. 7 DElncRNAs (PVT1, LINC01138, LINC02499, AL355488.2, FGF14-AS2, MAFG-AS1 and LINC00261) were finally identified as prognostic indicators. The area under the curve reached 0.8169 for the 7-lncRNA signature. The predictive accuracy and clinical application value were remarkably high for the genomic-clinicopathologic nomogram integrating the histological grade and the 7-gene-based prognostic index. Taken together, we have established a ceRNA network with HBV-related HCC-specific DElncRNAs, DEmiRNAs, and DEmRNAs. Furthermore, the genome-wide data of lncRNA expression were analyzed using the TCGA database, and a 7-lncRNA signature was identified as a potential prognostic predictor for HBV-related HCC patients. Novel functional studies were provided by our current findings for elucidating the molecular mechanism of lncRNA in HBV-related HCC.

Loss of SNORA73 reprograms cellular metabolism and protects against steatohepatitis

Dyslipidemia and resulting lipotoxicity are pathologic signatures of metabolic syndrome and type 2 diabetes. Excess lipid causes cell dysfunction and induces cell death through pleiotropic mechanisms that link to oxidative stress. However, pathways that regulate the response to metabolic stress are not well understood. Herein, we show that disruption of the box H/ACA SNORA73 small nucleolar RNAs encoded within the small nucleolar RNA hosting gene 3 (Snhg3) causes resistance to lipid-induced cell death and general oxidative stress in cultured cells. This protection from metabolic stress is associated with broad reprogramming of oxidative metabolism that is dependent on the mammalian target of rapamycin signaling axis. Furthermore, we show that knockdown of SNORA73 in vivo protects against hepatic steatosis and lipid-induced oxidative stress and inflammation. Our findings demonstrate a role for SNORA73 in the regulation of metabolism and lipotoxicity.

Screening Prognosis-Related lncRNAs Based on WGCNA to Establish a New Risk Score for Predicting Prognosis in Patients with Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) remains an important cause of cancer death. The molecular mechanism of hepatocarcinogenesis and prognostic factors of HCC have not been completely uncovered.

METHODS

In this study, we screened out differentially expressed lncRNAs (DE lncRNAs), miRNAs (DE miRNAs), and mRNAs (DE mRNAs) by comparing the gene expression of HCC and normal tissue in The Cancer Genome Atlas (TCGA) database. DE mRNAs were used to perform Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Then, the miRNA and lncRNA/mRNA modules that were most closely related to the survival time of patients with HCC were screened to construct a competitive endogenous RNA (ceRNA) network by weighted gene coexpression network analysis (WGCNA). Moreover, univariable Cox regression and Kaplan-Meier curve analyses of DE lncRNAs and DE mRNAs were conducted. Finally, the lasso-penalized Cox regression analysis and nomogram model were used to establish a new risk scoring system and predict the prognosis of patients with liver cancer. The expression of survival-related DE lncRNAs was verified by qRT-PCR.

RESULTS

A total of 1896 DEmRNAs, 330 DElncRNAs, and 76 DEmiRNAs were identified in HCC and normal tissue samples. Then, the turquoise miRNA and turquoise lncRNA/mRNA modules that were most closely related to the survival time of patients with HCC were screened to construct a ceRNA network by WGCNA. In this ceRNA network, there were 566 lncRNA-miRNA-mRNA regulatory pairs, including 30 upregulated lncRNAs, 16 downregulated miRNAs, and 75 upregulated mRNAs. Moreover, we screened out 19 lncRNAs and 14 hub mRNAs related to prognosis from this ceRNA network by univariable Cox regression and Kaplan-Meier curve analyses. Finally, a new risk scoring system was established by selecting the optimal risk lncRNAs from the 19 prognosis-related lncRNAs through lasso-penalized Cox regression analysis. In addition, we established a nomogram model consisting of independent prognostic factors to predict the survival rate of HCC patients. Finally, the correlation between the risk score and immune cell infiltration and gene set enrichment analysis were determined.

CONCLUSIONS

In conclusion, the results may provide potential biomarkers or therapeutic targets for HCC and the establishment of the new risk scoring system and nomogram model provides the new perspective for predicting the prognosis of HCC.

Tumor infiltrating lymphocytes associated competitive endogenous RNA networks as predictors of outcome in hepatic carcinoma based on WGCNA analysis

Background

The important regulatory role of competitive endogenous RNAs (ceRNAs) in hepatocellular carcinoma (HCC) has been confirmed. Tumor infiltrating lymphocytes (TILs) are of great significance to tumor outcome and prognosis. This study will systematically analyze the key factors affecting the prognosis of HCC from the perspective of ceRNA and TILs.

Methods

The Cancer Genome Atlas (TCGA) database was used for transcriptome data acquisition of HCC. Through the analysis of the Weighted Gene Co-expression Network Analysis (WCGNA), the two modules for co-expression of the disease were determined, and a ceRNA network was constructed. We used Cox regression and LASSO regression analysis to screen prognostic factors and constructed a risk score model. The Gene Expression Omnibus (GEO) was used to validate the model. The Kyoto Encyclopedia of Genes and Genomes (KEGG) was used for mRNAs functional analysis. The cell composition of TILs was analyzed by the CIBERSORT algorithm, and Pearson correlation analysis was utilized to explore the correlation between TILs and prognostic factors.

Results

We constructed a ceRNA regulatory network composed of 67 nodes through WGCNA, including 44 DElncRNAs, 19 DEGs, and 4 DEmiRNAs. And based on the expression of 4 DEGs in this network (RRM2, LDLR, TXNIP, and KIF23), a prognostic model of HCC with good specificity and sensitivity was developed. CIBERSORT analyzed the composition of TILs in HCC tumor tissues. Correlation analysis showed that RRM2 is significantly correlated with T cells CD4 memory activated, T cells CD4 memory resting, T cells CD8, and T cells follicular helper, and TXNIP is negatively correlated with B cells memory.

Conclusions

In this study, a ceRNA with prognostic value in HCC was created, and a prognostic risk model for HCC was constructed based on it. This risk score model is closely related to TILs and is expected to become a potential therapeutic target and a new predictive indicator.

Construction of Novel lncRNA-miRNA-mRNA Network Associated With Recurrence and Identification of Immune-Related Potential Regulatory Axis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant diseases globally. Despite continuous improvement of treatment methods, high postoperative recurrence rate remains an urgent problem. In order to determine the mechanism underlying recurrence of liver cancer and identify prognostic genes, data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were integrated and analyzed. Differentially expressed genes (DEGs) between HCC tissue and normal liver tissue were identified, and a protein–protein interaction network was constructed to find hub genes. Clinical correlation analysis and disease-free survival (DFS) analysis were performed using the R language and GEPIA to identify relapse-related genes. Correlation analysis was used to identify a potential regulatory axis. Dual-luciferase reporter gene assay was used to confirm the reliability of the long non-coding RNA (lncRNA)–microRNA (miRNA)–mRNA regulatory axis. Immune infiltration analysis was performed using the TIMER database. Correlations between immune gene markers and ASF1B were verified using quantitative real-time polymerase chain reaction (RT-qPCR). In this work, we found that nine lncRNAs and five mRNAs were significantly overexpressed in HCC tissues from patients with recurrence. SNHG3, LINC00205, ASF1B, AURKB, CCNB1, CDKN3, and DTL were also closely related to HCC grade and stage. Survival analysis showed that these seven DEGs were significantly correlated with poor DFS. Correlation analysis identified SNHG3–miR-214-3p–ASF1B as a potential regulatory axis. Dual-luciferase reporter gene assay showed that SNHG3 and ASF1B directly bound to miR-214-3p. ASF1B was negatively regulated by miRNA-214-3p, and overexpression of SNHG3 could inhibit the expression of miRNA-214-3p. In addition, ASF1B was positively correlated with immune infiltration. A reduction in ASF1B could markedly inhibit the expression of CD86, CD8, STAT1, STAT4, CD68, and PD1 in HCC cells. Flow cytometry showed that SNHG3 promoted the PD-1 expression by regulating ASF1B. Meanwhile, elevated ASF1B predicted poor prognosis of HCC patients in subgroups with decreased B cells, CD8+ T cells, or neutrophils, and those with enriched CD4+ T cells. In conclusion, we found that a novel lncRNA SNHG3/miR-214-3p/ASF1B axis could promote the recurrence of HCC by regulating immune infiltration.

Long noncoding RNA SNHG3 promotes glioma tumorigenesis by sponging miR-485-5p to upregulate LMX1B expression

LIM homeobox transcription factor 1-beta (LMX1B) has recently been found to be highly expressed in advanced gliomas and is associated with poor survival. However, the regulatory molecular mechanism of LMX1B expression in gliomas remains unclear. In this study, bioinformatics analysis showed that miR-485-5p may be the potential upstream regulator of LMX1B, and long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) may function as a competitive endogenous RNA to sponge miR-485-5p. In addition, the expression of SNHG3 and LMX1B in advanced glioma tissues was significantly upregulated, while the expression of miR-485-5p was significantly downregulated. SNHG3 overexpression reduced the expression of miR-485-5p; increased the expression of LMX1B; and promoted the proliferation, migration, and invasion of glioma cells. In contrast, miR-485-5p overexpression reduced the expression of LMX1B and inhibited cell proliferation, migration, and invasion. The luciferase reporter assay and RNA immunoprecipitation assay further confirmed the interaction between SNHG3 and miR-485-5p and between miR-485-5p and LMX1B. In addition, subcutaneous and orthotropic xenograft models confirmed that lncRNA SNHG3 silencing or miR-485-5p overexpression significantly reduced the growth of glioma xenografts and prolonged survival time. These results indicate that lncRNA SNHG3 can regulate the expression of LMX1B by sponging miR-485-5p, thereby promoting the proliferation, migration, and invasion of glioma cells. This study provides the first evidence that the SNHG3/miR-485-5p/LMX1B axis is involved in glioma tumorigenesis and highlights the potential of SNHG3 and miR-485-5p as therapeutic targets for glioma.

Long non-coding RNA TTN antisense RNA 1 facilitates hepatocellular carcinoma progression via regulating miR-139-5p/SPOCK1 axis

Reportedly, long non-coding RNAs (lncRNAs) are implicated in hepatocellular carcinoma (HCC) progression, yet little is known concerning the biological functions of TTN antisense RNA 1 (TTN-AS1) in HCC. In this study, quantitative real-time polymerase chain reaction (qRT-PCR) was performed for detecting TTN-AS1, SPOCK1 mRNA, and miR-139-5p expressions in HCC cells and tissues. After TTN-AS1 was overexpressed or knocked down in HCC cells, CCK-8 and 5-Ethynyl-2ʹ-deoxyuridine (EdU) assays were carried out for examining cell multiplication. Transwell assays were conducted for evaluating HCC cell migration and invasion. Dual-luciferase reporter assay was employed for verifying the binding relationships between miR-139-5p and TTN-AS1, and between SPOCK1 3ʹUTR and miR-139-5p. Western blot was employed to measure SPOCK1, E-cadherin, N-cadherin, and Vimentin protein expressions. We demonstrated that, TTN-AS1 and SPOCK1 expression levels were remarkably enhanced in HCC cells and tissues, whereas miR-139-5p expression was observably reduced. Functional experiments suggested that TTN-AS1 knockdown markedly repressed HCC cell multiplication, migration, epithelial-mesenchymal transition (EMT), and invasion. In addition, TTN-AS1 interacted with miR-139-5p and decreased its expression. Moreover, SPOCK1 was a miR-139-5p target, and miR-139-5p inhibitors were able to reverse TTN-AS1 knockdown-induced inhibitory effect on SPOCK1 expression. SPOCK1 overexpression plasmid could counteract TTN-AS1 knockdown-induced inhibiting impact on HCC cell multiplication, migration, invasion, and EMT. In conclusion, TTN-AS1 expression level is remarkably enhanced in HCC, and TTN-AS1 can promote the multiplication, migration, invasion, and EMT of HCC cells via regulating miR-139-5p/SPOCK1 axis.

SNHG3 Knockdown Suppresses Proliferation, Migration and Invasion, and Promotes Apoptosis in Non-Small Cell Lung Cancer Through Regulating miR-216a/ZEB1 Axis

Background

Tumour growth and development are dependent on many factors including long noncoding RNAs (lncRNAs). However, limited information is available on the involvement of lncRNAs in non-small cell lung cancer (NSCLC) and the molecular mechanisms have not been defined. Here, we examined the expression of small nucleolar RNA host gene 3 (SNHG3) and its contribution to the development of NSCLC.

Methods

We detected SNHG3, miR-216a, and ZEB1 expression in tissues from NSCLC patients and lung adenocarcinoma cell lines using quantitative real-time polymerase chain reaction. Proliferation, migrations, invasion, and apoptosis of tumour cells were assessed using cell counting kit-8, transwell experiments, and flow cytometry after SNHG3 knockdown by small interfering RNAs. Bioinformatics and luciferase reporter assays were employed for analysing the interactions between SNHG3, miR-216a, and ZEB1.

Results

We found highly upregulated SNHG3 in tissues and cells from NSCLC patients, which was linked to poor prognosis. SNHG3 silencing diminished the ability of NSCLC cells to proliferate, migrate, and invade and promoted apoptosis. Furthermore, SNHG3 competed with endogenous RNA and enhanced the expression of ZEB1 by interfering with miR-216a. ZEB1 overexpression or miR-216a blockade reversed SNHG3-induced tumour inhibition. Similar effects were observed in vivo where SNHG3 knockdown inhibited NSCLC tumour growth by reducing expression of miR-216a while increasing that of ZEB1.

Conclusion

Knockdown of SNHG3 inhibits NSCLC tumour development and progression by upregulation of ZEB1 and interference with miR-216a, revealing an attractive alternative target for patients with NSCLC.

LncRNA SNHG3, a potential oncogene in human cancers

Long noncoding RNAs (lncRNAs) are composed of > 200 nucleotides; they lack the ability to encode proteins but play important roles in a variety of human tumors. A large number of studies have shown that dysregulated expression of lncRNAs is related to tumor oncogenesis and progression. Emerging evidence shows that SNHG3 is a novel oncogenic lncRNA that is abnormally expressed in various tumors, including osteosarcoma, liver cancer, lung cancer, etc. SNHG3 primarily competes as a competitive endogenous RNA (ceRNA) that targets tumor suppressor microRNAs (miRNAs) and ceRNA mechanisms that regulate biological processes of tumors. In addition, abnormal expression of SNHG3 is significantly correlated with patient clinical features. Upregulation of SNHG3 contributes to biological functions, including tumor cell proliferation, migration, invasion and EMT. Therefore, SNHG3 may represent a potential diagnostic and prognostic biomarker, as well as a novel therapeutic target.

lncRNA SNHG3 promotes breast cancer progression by acting as a miR‑326 sponge

Accumulating evidence suggests that long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SHNG3) plays crucial roles in the initiation and progression of various types of malignant cancers. Yet, the role played by SNHG3 in breast cancer as well as the associated mechanisms remain largely unclear. The expression of SNHG3 was detected in breast cancer tissues and cell lines by reverse-transcription quantitative PCR (RT-qPCR). Cell proliferation, colony formation, cell cycle distribution, migration and invasion abilities were detected by Cell Counting Kit-8, colony formation assay, flow cytometry, wound-healing and Matrigel invasion assays, respectively. The regulatory relationships between SNHG3 and miR-326 were explored by luciferase reporter assay. A nude mouse model was established to investigate the effect of SNHG3 in vivo. The results showed an upregulation of SNHG3 in breast cancer tissues and cell lines. Loss-of-function assays revealed significant suppression of breast cancer behaviors such as: Abilities to proliferate, form colonies, migrate and invade in vitro coupled with a delayed growth of tumors in vivo when SNHG3 was knocked down. Mechanically, it was shown that SNHG3 served as a competing endogenous RNA (ceRNA) of miR-326 that in turn is a tumor suppressor in this cancer. The correlation between the expression of SNHG3 and miR-326 was found to be strongly negative in these samples. Additionally, we found that inhibition of SNHG3 caused a partially reversal in the inhibition exerted by miR-326 on the ability of these cells to proliferate, form colonies, migrate and invade. Collectively, these findings suggest the functioning of SNHG3 as a ceRNA to enhance the ability of breast cancer cells to proliferate and metastasize to putatively serve as a new target to explore therapeutic intervention of this malignancy.

Diagnostic, prognostic, and therapeutic significance of miR-139-5p in cancers

miRNAs are a group of non-coding RNAs that have regulatory functions in post-transcriptional gene expression. These molecules play a fundamental role in cellular processes, for instance cell proliferation, apoptosis, migration, and invasion. Scientific investigations have previously established that miRNAs can either promote or suppress tumor development by mediating different signaling pathways. miR-139-5p, located on chromosome 11q13.4, has been examined extensively in cancers. Studies have demonstrated that miR-139-5p might be an attractive cancer biomarker. Herein, we will review how miR-139-5p acts in cancer diagnosis, prognosis, and therapy, as well as elucidating its major target genes and associated signaling pathways.

Transcriptome analysis revealed key prognostic genes and microRNAs in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. However, the molecular mechanisms involved in HCC remain unclear and are in urgent need of elucidation. Therefore, we sought to identify biomarkers in the prognosis of HCC through an integrated bioinformatics analysis.

Methods

Messenger RNA (mRNA) expression profiles were obtained from the Gene Expression Omnibus database and The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) for the screening of common differentially expressed genes (DEGs). Function and pathway enrichment analysis, protein-protein interaction network construction and key gene identification were performed. The significance of key genes in HCC was validated by overall survival analysis and immunohistochemistry. Meanwhile, based on TCGA data, prognostic microRNAs (miRNAs) were decoded using univariable and multivariable Cox regression analysis, and their target genes were predicted by miRWalk.

Results

Eleven hub genes (upregulated ASPM, AURKA, CCNB2, CDC20, PRC1 and TOP2A and downregulated AOX1, CAT, CYP2E1, CYP3A4 and HP) with the most interactions were considered as potential biomarkers in HCC and confirmed by overall survival analysis. Moreover, AURKA, PRC1, TOP2A, AOX1, CYP2E1, and CYP3A4 were considered candidate liver-biopsy markers for high risk of developing HCC and poor prognosis in HCC. Upregulation of hsa-mir-1269b, hsa-mir-518d, hsa-mir-548aq, hsa-mir-548f-1, and hsa-mir-6728, and downregulation of hsa-mir-139 and hsa-mir-4800 were determined to be risk factors of poor prognosis, and most of these miRNAs have strong potential to help regulate the expression of key genes.

Conclusions

This study undertook the first large-scale integrated bioinformatics analysis of the data from Illumina BeadArray platforms and the TCGA database. With a comprehensive analysis of transcriptional alterations, including mRNAs and miRNAs, in HCC, our study presented candidate biomarkers for the surveillance and prognosis of the disease, and also identified novel therapeutic targets at the molecular and pathway levels.

Knockdown of LINC00473 Enhances Radiosensitivity in Hepatocellular Carcinoma via Regulating the miR-345-5p/FOXP1 Axis

Background

Hepatocellular carcinoma (HCC) is the most common form of liver cancer. Radioresistance is a significant obstacle in HCC therapy. Long non-coding RNA 473 (LINC00473) has been found to impair the effect of radiotherapy. This study aimed to explore the function and molecular basis of LINC00473 in the radiosensitivity of HCC cells.

Methods

The levels of LINC00473, miR-345-5p and Forkhead Box P1 (FOXP1) were determined by quantitative real-time polymerase chain reaction. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Survival fraction was calculated by colony survival assay after exposure to different doses of radiation. Cell apoptosis was evaluated by flow cytometry. The interaction among LINC00473, miR-345-5p and FOXP1 was confirmed by dual-luciferase reporter assay. The protein level of FOXP1 was detected by Western blot assay.

Results

LINC00473 and FOXP1 were up-regulated, while miR-345-5p was down-regulated in HCC tissues and cells. Radiation elevated LINC00473 expression in a dose- and time-dependent manner. Depletion of LINC00473 inhibited proliferation and heightened radiosensitivity and apoptosis in HCC cells. In addition, LINC00473 was a sponge of miR-345-5p. Also, miR-345-5p overexpression sensitized HCC cells to radiation. Moreover, miR-345-5p directly targeted FOXP1. MiR-345-5p inhibition or FOXP1 up-regulation reversed the enhanced radiosensitivity caused by LINC00473 knockdown.

Conclusion

LINC00473 contributed to radioresistance in HCC via modulating the miR-345-5p/FOXP1 axis, which might provide a promising diagnostic marker for HCC radiotherapy.