MEG3-derived miR-493-5p overcomes the oncogenic feature of IGF2-miR-483 loss of imprinting in hepatic cancer cells

Harnessing the supremacy of MEG3 LncRNA to defeat gastrointestinal malignancies

Evidence suggests that long non-coding RNAs (lncRNAs) play a pivotal role in the carcinogenesis and progression of various human malignancies including gastrointestinal malignancies. This comprehensive review reports the functions and mechanisms of the lncRNA maternally expressed gene 3 (MEG3) involved in gastrointestinal malignancies. It summarizes its roles in mediating the regulation of cellular proliferation, apoptosis, migration, invasiveness, epithelial-to-mesenchymal transition, and drug resistance in several gastrointestinal cancers such as colorectal cancer, gall bladder cancer, pancreatic cancer, gastric cancer, esophageal cancer, cholangiocarcinoma, gastrointestinal stromal tumors and most importantly, hepatocellular carcinoma. In addition, the authors briefly highlight its implicated mechanistic role and interactions with different non-coding RNAs and oncogenic signaling cascades. This review presents the rationale for developing non coding RNA-based anticancer therapy via harnessing the power of MEG3 in gastrointestinal malignancies.

Human IGF2 Gene Epigenetic and Transcriptional Regulation: At the Core of Developmental Growth and Tumorigenic Behavior

Regulation of the human IGF2 gene displays multiple layers of control, which secures a genetically and epigenetically predetermined gene expression pattern throughout embryonal growth and postnatal life. These predominantly nuclear regulatory mechanisms converge on the function of the IGF2-H19 gene cluster on Chromosome 11 and ultimately affect IGF2 gene expression. Deregulation of such control checkpoints leads to the enhancement of IGF2 gene transcription and/or transcript stabilization, ultimately leading to IGF-II peptide overproduction. This type of anomaly is responsible for the effects observed in terms of both abnormal fetal growth and increased cell proliferation, typically observed in pediatric overgrowth syndromes and cancer. We performed a review of relevant experimental work on the mechanisms affecting the human IGF2 gene at the epigenetic, transcriptional and transcript regulatory levels. The result of our work, indeed, provides a wider and diversified scenario for IGF2 gene activation than previously envisioned by shedding new light on its extended regulation. Overall, we focused on the functional integration between the epigenetic and genetic machinery driving its overexpression in overgrowth syndromes and malignancy, independently of the underlying presence of loss of imprinting (LOI). The molecular landscape provided at last strengthens the role of IGF2 in cancer initiation, progression and malignant phenotype maintenance. Finally, this review suggests potential actionable targets for IGF2 gene- and regulatory protein target-degradation therapies.

Effect of miR-493-5p on proliferation and differentiation of myoblast by targeting ANKRD17

The hypertrophy and conversion of postnatal muscle fibers largely determine the yield and quality of meat, which is closely related to the economic value of pigs. MicroRNA (miRNA), as a kind of endogenous noncoding RNA molecule, is widely involved in myogenesis of livestock and poultry. The longissimus dorsi tissues of Lantang pigs at 1 and 90 days (LT1D and LT90D) were collected and profiled by miRNA-seq. We found 1871 and 1729 miRNA candidates in LT1D and LT90D samples, and 794 miRNAs were shared. We identified 16 differentially expressed miRNAs between two tested groups and explored the function of miR-493-5p inmyogenesis. The miR-493-5p promoted the proliferation and inhibited the differentiation of myoblasts. Using GO and KEGG analyses of 164 target genes of miR-493-5p, we found that ATP2A2, PPP3CA, KLF15, MED28, and ANKRD17 genes were related to muscle development. RT-qPCR detection showed that the expression level of ANKRD17 was highly expressed in LT1D libraries, and the double luciferase report test preliminarily proved that miR-493-5p and ANKRD17 have a directly targeting relationship. We established miRNA profiles for the longissimus dorsi tissues of 1-day-old and 90-day-old Lantang pigs and found that miR-493-5p was differentially expressed and associated with myogenesis by targeting ANKRD17 gene. Our results should serve as a reference for future studies on pork quality.

Synergic Action of Insulin-like Growth Factor-2 and miRNA-483 in Pterygium Pathogenesis

Pterygium is a multifactorial disease in which UV-B is speculated to play a key role by inducing oxidative stress and phototoxic DNA damage. In search for candidate molecules that are useful for justifying the intense epithelial proliferation observed in pterygium, our attention has been focused on Insulin-like Growth Factor 2 (IGF-2), mainly detected in embryonic and fetal somatic tissues, which regulate metabolic and mitogenic functions. The binding between IGF-2 and its receptor Insulin-like Growth Factor 1 Receptor (IGF-1R) activates the PI3K-AKT pathway, which leads to the regulation of cell growth, differentiation, and the expression of specific genes. Since IGF2 is regulated by parental imprinting, in different human tumors, the IGF2 Loss of Imprinting (LOI) results in IGF-2- and IGF2-derived intronic miR-483 overexpression. Based on these activities, the purpose of this study was to investigate the overexpression of IGF-2, IGF-1R, and miR-483. Using an immunohistochemical approach, we demonstrated an intense colocalized epithelial overexpression of IGF-2 and IGF-1R in most pterygium samples (Fisher's exact test, p = 0.021). RT-qPCR gene expression analysis confirmed IGF2 upregulation and demonstrated miR-483 expression in pterygium compared to normal conjunctiva (253.2-fold and 12.47-fold, respectively). Therefore, IGF-2/IGF-1R co-expression could suggest their interplay through the two different paracrine/autocrine IGF-2 routes for signaling transfer, which would activate the PI3K/AKT signaling pathway. In this scenario, miR-483 gene family transcription might synergically reinforce IGF-2 oncogenic function through its boosting pro-proliferative and antiapoptotic activity.

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

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

Identification of Liver Fibrosis-Related MicroRNAs in Human Primary Hepatic Stellate Cells Using High-Throughput Sequencing

MicroRNAs (miRNAs) participate in hepatic stellate cell (HSC) activation, which drives liver fibrosis initiation and progression. We aimed to identify novel hepatic fibrosis targets using miRNA sequencing (miRNA-seq) of human primary HSCs. Surgically resected liver tissues were used to extract HSCs. Based on next-generation sequencing, miRNA-seq was performed on four pairs of HSCs before and after in vitro culture. Additionally, we compared our data with open access miRNA-seq data derived from fourteen cirrhotic and nine healthy liver tissues. Selected miRNAs associated with fibrosis were verified by quantitative real-time PCR. Target mRNAs of differentially expressed (DE) miRNAs were predicted to construct co-expression networks. We identified 230 DEmiRNAs (118 upregulated and 112 downregulated) upon HSC activation. Of the 17 miRNAs with the most significant differences in expression, liver disease-related miRNAs included miR-758-3p, miR-493-5p, miR-409-3p, miR-31-5p, miR-1268a, and miR-381-3p, which might play roles in hepatic fibrosis. Moreover, let-7g-5p, miR-107, miR-122-5p, miR-127-3p, miR-139-5p, miR-148a-3p, miR-194-5p, miR-215-5p, miR-26a-5p, miR-340-5p, miR-451a, and miR-99a-5p were common between our data and the publicly available sequencing data. A co-expression network comprising 1891 matched miRNA-mRNA pairs representing 138 DEmiRNAs and 1414 DEmRNAs was constructed. MiR-1268a and miR-665, possessing the richest target DEmRNAs, may be vital in HSC activation. The targeted genes were involved in collagen metabolism, extracellular matrix structural constituent, cytoskeletal protein binding, and cell adhesion. The miRNAs we identified may provide a basis and reference for the selection of diagnostic and therapeutic targets for hepatic fibrosis.

Melatonin and cancer suppression: insights into its effects on DNA methylation

Melatonin is an important naturally occurring hormone in mammals. Melatonin-mediated biological effects include the regulation of circadian rhythms, which is important for optimal human health. Also, melatonin has a broad range of immunoenhancing actions. Moreover, its oncostatic properties, especially regarding breast cancer, involve a variety cancer-inhibitory processes and are well documented. Due to their promising effects on the prognosis of cancer patients, anti-cancer drugs with epigenetic actions have attracted a significant amount of attention in recent years. Epigenetic modifications of cancers are categorized into three major processes including non-coding RNAs, histone modification, and DNA methylation. Hence, the modification of the latter epigenetic event is currently considered an effective strategy for treatment of cancer patients. Thereby, this report summarizes the available evidence that investigated melatonin-induced effects in altering the status of DNA methylation in different cancer cells and models, e.g., malignant glioma and breast carcinoma. Also, we discuss the role of artificial light at night (ALAN)-mediated inhibitory effects on melatonin secretion and subsequent impact on global DNA methylation of cancer cells.

Integrated bioinformatic analysis of dysregulated microRNA-mRNA co-expression network in ovarian endometriosis

INTRODUCTION

Ovarian endometriosis is a frequently occurring gynecological disease with large socioeconomic impact. Accumulating evidence has suggested that aberrant miRNA-mRNA interactions are involved in the pathogenesis and progression of ovarian endometriosis. This study aims to identify key miRNAs in ovarian endometriosis by using integrated bioinformatic analysis of a dysregulated miRNA-mRNA co-expression network.

MATERIAL AND METHODS

Expression profiling of miRNA and mRNA in three normal endometria and five pairs of ectopic/eutopic endometria from patients with ovarian endometriosis was determined by high-throughput sequencing techniques. The data were then integrated with the public sequencing datasets (GSE105764 and GSE105765) using a non-biased approach and a miRNA-mRNA co-expression regulatory network was constructed by in-depth bioinformatic analysis.

RESULTS

The constructed miRNA-mRNA network included 87 functionally DEMs, 482 target mRNAs and 1850 paired miRNA-mRNA regulatory interactions. Specifically, five miRNAs (miR-141-3p, miR-363-3p, miR-577, miR-767-5p, miR-96-5p) were gradually decreased and two miRNAs (miR-493-5p, miR-592) were gradually increased from normal endometria to eutopic endometria, and then ectopic endometria tissues. Importantly, miR-141-3p, miR-363-3p and miR-96-5p belonged to the miR-200 family, miR-106a-363 cluster and miR-183/96/182 cluster, respectively. Their target mRNAs were mainly associated with cell adhesion, locomotion and binding, which are suggested to play vital regulatory roles in the pathogenesis of ovarian endometriosis.

CONCLUSIONS

Integrated bioinformatic analysis of the miRNA-mRNA co-expression network defines the crucial roles of the miR-200 family, miR-106a-363 cluster and miR-183/96/182 cluster in the pathogenesis of ovarian endometriosis. Further in-depth functional studies are needed to unveil the molecular mechanisms of these miRNAs, and may provide clues for the optimization of therapeutic strategies for ovarian endometriosis.

LncRNA Meg3 knockdown reduces corneal neovascularization and VEGF-induced vascular endothelial angiogenesis via SDF-1/CXCR4 and Smad2/3 pathway

The crucial effect of vascular endothelial growth factor (VEGF)-induced vascular angiogenesis has been well known in corneal neovascularization (CNV). This research aimed to determine the underlying value and mechanism of Meg3 on CNV in vivo and in vitro. In an alkali-burned mouse model, length and area of new vessels were increased along with thinning of corneal epithelium, accompanied by the overexpression of Meg3. Notably, subconjunctival injection of shMeg3 suppressed the degree of injury in cornea, causing expression of the angiogenesis markers--VEGF-A and CD31 decreased. In VEGF-induced human umbilical vein endothelial cells (HUVECs), knockdown of Meg3 antagonized the enhancement of viability, proliferation, wound healing ability and angiogenesis by VEGF. The proteins expression of VEGF-A, CD31, SDF-1/CXCR4 as well as phosphoraylation-Smad2/3 pathways, which were related to angiogenesis, were reduced with Meg3 deficiency. Overall, knockdown of Meg3 alleviated formation of neovascularization in alkali-burned corneas and reduced VEGF-induced angiogenesis by inhibiting SDF-1/CXCR4 and Smad2/3 signaling in vitro.

Tumor-suppressive MEG3 induces microRNA-493-5p expression to reduce arabinocytosine chemoresistance of acute myeloid leukemia cells by downregulating the METTL3/MYC axis

Background

Chemoresistance serves as a huge obstacle for acute myeloid leukemia (AML) patients. To counteract the chemoresistance in AML cells, we discussed the role of maternally expressed gene 3 (MEG3) in arabinocytosine (AraC) chemoresistance in AML cells.

Methods

MEG3, microRNA (miR)-493-5p, methyltransferase-like 3 (METTL3) and MYC expression in AML cells was determined and then their interactions were also analyzed. Then, the viability and apoptosis of AML cells were determined through loss- and gain- function assay. The level of m6A modification in AML cells was examined. AML mouse models were also established to validate the potential roles of MEG3.

Results

MEG3 and miR-493-5p were downregulated in AML cells, and they were lower in resistant cells than in parental cells. MEG3 led to elevated expression of miR-493-5p which targeted METTL3. METTL3 increased expression of MYC by promoting its m6A levels. Overexpression of MEG3 and miR-493-5p or knockdown of METTL3 inhibited HL-60 and Molm13 cell proliferation and promoted their apoptosis. Overexpressed MEG3 induced heightened sensitivity of AML cells to AraC. However, the suppression of miR-493-5p reversed the effects of overexpressed MEG3 on AML cells.

Conclusions

Collectively, MEG3 could upregulate miR-493-5p expression and suppress the METTL3/MYC axis through MYC m6A methylation, by which MEG3 promoted the chemosensitivity of AML cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03456-x.

Knockdown of long noncoding RNA HUMT inhibits the proliferation and metastasis by regulating miR-455-5p/LRP4 axis in hepatocellular carcinoma

The present study aimed at investigating the effects and mechanism of long noncoding RNA highly upregulated in metastatic triple-negative breast cancer lymph node (lncRNA HUMT) in hepatocellular carcinoma (HCC). Quantitative real-time polymerase chain reaction was used to assess the expression of HUMT, microRNA (miR)-455-5p, and low-density lipoprotein receptor-related protein 4 (LRP4) in HCC tissues. Colony forming and 5-ethynyl-2′-deoxyuridine assays were performed to assess cell proliferation. Transwell assay was performed to measure cell migration and invasion. Cell cycle distribution was assessed using flow cytometry. The protein expression of LRP4, proliferating cell nuclear antigen (PCNA), matrix metallopeptidase 2 (MMP-2), and MMP-9 was detected using western blot. Luciferase reporter assay and RNA immunoprecipitation assay was used to confirm the target association between miR-455-5p and HUMT or LRP4. In our study, the level of HUMT was enhanced in HCC tissues and cells. Cell proliferation, invasion, and migration in HCC cells were repressed by knockdown of HUMT, and knockdown of HUMT arrested cells in G1 phase and decreased the levels of PCNA, MMP-2, and MMP-9. MiR-455-5p was a target of HUMT. Lowexpression of miR-455-5p reversed the inhibitive influence on HCC cells induced by of HUMT silencing. LRP4 was a target of miR-455-5p and was negatively regulated by miR-455-5p. In addition, LRP4 expression was positively modified by HUMT, and LRP4 inhibited the inhibitory effects on HCC cells induced by HUMT silencing. In conclusion, HCC cell proliferation, invasion, and migration were restrained by knockdown of HUMT, which was related to the miR-455-5p/LRP4 axis.

MiR-20b-5p promotes hepatocellular carcinoma cell proliferation, migration and invasion by down-regulating CPEB3

INTRODUCTION AND OBJECTIVES

This study aimed to explore the functional mechanism of the miRNA-20b-5p/cytoplasmic polyadenylation element binding protein 3 (miR-20b-5p/CPEB3) axis in hepatocellular carcinoma (HCC) so as to provide a new idea for targeted therapy of HCC.

MATERIALS AND METHODS

Bioinformatics analysis was employed to obtain markedly differentially expressed miRNAs and mRNAs in The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) dataset, so as to find target miRNA and its target mRNA. Real-time quantitative PCR was conducted to detect miR-20b-5p and CPEB3 mRNA expression. Western blot was performed to determine CPEB3 protein expression. Dual-luciferase reporter assay was carried out to verify the targeting relationship between miR-20b-5p and CPEB3. Cell counting kit-8 assay, wound healing assay, Transwell invasion assay and flow cytometry were conducted to evaluate the proliferation, migration, invasion and apoptosis of HCC cells.

RESULTS

Bioinformatics analysis suggested that miR-20b-5p and CPEB3 were markedly highly and lowly expressed, respectively, in HCC tissue in TCGA-LIHC dataset. Over-expressing miR-20b-5p facilitated the proliferation, migration and invasion, and suppressed the apoptosis of HCC cells. Dual-luciferase reporter assay validated that there was a targeting relationship between miR-20b-5p and CPEB3. The inhibitory effect of CPEB3 over-expression on HCC cell proliferation, migration and invasion was reversed by over-expressing miR-20b-5p.

CONCLUSIONS

The present study proved that miR-20b-5p promotes HCC cell proliferation, migration and invasion by inhibiting CPEB3 expression, which may provide a theoretical basis for the prognosis and treatment of HCC patients.

Emerging role of long noncoding RNAs in recurrent hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most frequent types of liver cancer and is characterized by a high recurrence rate. Recent studies have proposed that long non-coding RNAs (lncRNAs) are potential biomarkers in several recurrent tumor types. It is now well understood that invasion, migration, and metastasis are important factors for tumor recurrence. Moreover, some of the known risk factors for HCC may affect the expression levels of several types of lncRNAs and thus affect the recurrence of liver cancer through lncRNA regulation. In this paper, we review the biological functions, molecular mechanisms, and roles of lncRNAs in HCC and summarize current knowledge about lncRNAs as potential biomarkers in recurrent HCC.

LncRNA RGMB-AS1 up-regulates ANKRD1 through competitively sponging miR-3614-5p to promote OSA cell proliferation and invasion

BACKGROUND

Osteosarcoma (OSA) is associated with unfavorable prognosis. The overall survival rate for patients with OSA recurrence or metastasis is only about 20%. Long non-coding RNAs (lncRNAs) significantly function in gene expression and the progression of various cancers including OSA.

METHODS

The expression of repulsive guidance molecule BMP co-receptor b antisense RNA 1 (RGMB-AS1) was detected in OSA cells via qRT-PCR. Western blot assay exposed the protein level of ankyrin repeat domain 1 (ANKRD1). The function assays showed the role of RGMB-AS1, miR-3614-5p, ANKRD1 on OSA cell proliferation and invasion. Subcellular Fraction assay was conducted to detect RGMB-AS1 localization. Rescue assays manifested the mechanism of RGMB-AS1/miR-3614-5p/ANKRD1 axis in OSA cells.

RESULTS

FOXA1-activated RGMB-AS1 positively regulated OSA cell progression including proliferation and invasion but negatively modulated apoptosis. miR-3614-5p interacted with RGMB-AS1 and functioned as the tumor suppressor in OSA cells. ANKRD1 was targeted by miR-3614-5p and was negatively interacted by miR-3614-5p. RGMB-AS1 and ANKRD1 competitively bound with miR-3614-5p. The suppression of silencing RGMB-AS1 on OSA cell progression was rescued by ANKRD1 overexpression or miR-3614-5p down-regulation.

CONCLUSIONS

FOXA1-activated RGMB-AS1 promoted cell proliferation and invasion in OSA via miR-3614-5p/ANKRD1 pathway.

LncRNA MEG3 inhibits the proliferation of neural stem cells after ischemic stroke via the miR-493-5P/MIF axis

OBJECTIVE

The proliferation of neural stem cells (NSCs1), or lack thereof, can have profound effects on brain tissue remodeling for ischemic stroke (IS2). In this study, we aimed to reveal the influence of the lncRNA MEG3/miR-493-5p/MIF axis on NSC proliferation after IS.

METHODS

We established an oxygen glucose-deprivation/reoxygenation (OGD/R3) in vitro model of IS in NSCs. We evaluated NSC isolation efficiency and proliferation by NESTIN, SOX2, and PCNA immunofluorescence staining. MEG3 and miR-493-5P levels were assessed by quantitative real-time polymerase chain reaction (qRT-PCR4). Changes in MIF protein expression levels were analyzed using Western blotting. We then evaluated the role of MEG3 and miR-493-5p by transfection of si-MEG3, a miR-493-5p mimic, or miR-493-5p inhibitor. NSC proliferation was quantified using Cell Counting Kit-8 analysis.

RESULTS

NESTIN and SOX2 were co-expressed in endogenous NSCs. Following OGD/R, MEG3 and miR-493-5P were significantly upregulated in NSCs, while MIF levels decreased and proliferation was inhibited. Knockdown of MEG3 inhibited miR-493-5p and rescued expression of MIF and PCNA, restoring cellular proliferation levels. In NSCs transfected with a miR-493-5p mimic or inhibitor, MIF levels were down- or upregulated, respectively. Consistently, transfection of a miR-493-5p mimic reduced NSC proliferation, while transfection with a miR-493-5p inhibitor or si-MEG3 rescued the inhibitory effect of OGD/R on NSC proliferation. After co-transfection of si-MEG3 and a miR-493-5p mimic of OGD/R-induced NSCs, levels of PCNA, an indicator of cellular proliferation, were significantly reduced. Conclusion MEG3 inhibits NSC proliferation of after IS via positive regulation of miR-493-5p and potential subsequent downregulation of MIF.

miR-4293 upregulates lncRNA WFDC21P by suppressing mRNA-decapping enzyme 2 to promote lung carcinoma proliferation

Non-coding RNAs (ncRNAs) involve in diverse biological processes by post-transcriptional regulation of gene expression. Emerging evidence shows that miRNA-4293 plays a significant role in the development of non-small cell lung cancer. However, the oncogenic functions of miR-4293 have not been studied. Our results demonstrated that miR-4293 expression is markedly enhanced in lung carcinoma tissue and cells. Moreover, miR-4293 promotes tumor cell proliferation and metastasis but suppresses apoptosis. Mechanistic investigations identified mRNA-decapping enzyme 2 (DCP2) as a target of miR-4293 and its expression is suppressed by miR-4293. DCP2 can directly or indirectly bind to WFDC21P and downregulates its expression. Consequently, miR-4293 can further promote WFDC21P expression by regulating DCP2. With a positive correlation to miR-4293 expression, WFDC21P also plays an oncogenic role in lung carcinoma. Furthermore, knockdown of WFDC21P results in functional attenuation of miR-4293 on tumor promotion. In vivo xenograft growth is also promoted by both miR-4293 and WFDC21P. Overall, our results establish oncogenic roles for both miR-4293 and WFDC21P and demonstrate that interactions between miRNAs and lncRNAs through DCP2 are important in the regulation of carcinoma pathogenesis. These results provided a valuable theoretical basis for the discovery of lung carcinoma therapeutic targets and diagnostic markers based on miR-4293 and WFDC21P.

Circ-CSPP1 knockdown suppresses hepatocellular carcinoma progression through miR-493-5p releasing-mediated HMGB1 downregulation

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for over 80% of primary liver cancers and leads to a high death rate. Research on circular RNAs (circRNAs) suggests that circRNAs are promising biomarkers for cancer treatment. This study aimed to explore the function of a novel circRNA (circ-CSPP1) in HCC.

METHODS

Circ-CSPP1 was obtained from the microarray data downloaded from the Gene Expression Omnibus (GEO) database. The expression of circ-CSPP1, miR-493-5p and high mobility group box 1 (HMGB1) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, colony formation ability, migration and invasion were monitored using cell counting kit-8 (CCK-8) assay, colony formation assay, wound healing assay and transwell assay, respectively. The protein levels of CyclinD1, Vimentin, matrix metallopeptidase 9 (MMP-9) and HMGB1 were detected by western blot. Xenograft models were established to investigate the function of circ-CSPP1 in vivo. The association between miR-493-5p and circ-CSPP1 or HMGB1 was predicted by the online tool starBase and ensured by dual-luciferase reporter assay.

RESULTS

The expression of circ-CSPP1 and HMGB1 was elevated, while the expression of miR-493-5p was declined in HCC tissues and cells. Circ-CSPP1 knockdown not only depleted HCC cell proliferation, formation, migration and invasion in vitro but also inhibited tumor growth in vivo. MiR-493-5p was a target of circ-CSPP1, and HMGB1 was a target of miR-493-5p. Rescue experiments presented that miR-493-5p deficiency reversed the effects of circ-CSPP1 knockdown, and HMGB1 overexpression reversed the effects of miR-493-5p restoration. Circ-CSPP1 sponged miR-493-5p to regulate HMGB1 expression.

CONCLUSION

Knockdown of circ-CSPP1 suppressed HCC development both in vitro and in vivo by upregulation of miR-493-5p and downregulation of HMGB1, hinting that circ-CSPP1 participated in HCC pathogenesis.

Epigenetic reprogramming promotes the antiviral action of IFNα in HBV-infected cells

Chronic hepatitis B virus (HBV) infections remain a health burden affecting ~250 million people worldwide. Thus far, available interferon-alpha (IFNα)-based therapies have shown unsatisfactory cure rates, and alternative therapeutic molecules are still required. However, their development has been hampered because accessible cell models supporting relevant HBV replication and appropriate antiviral activity are lacking. Strategies that reverse epigenetic alterations offer a unique opportunity for cell reprogramming, which is valuable for restoring altered cellular functions in human cell lines. This work aimed to investigate the feasibility of converting HepG2 cells that stably overexpress the HBV entry receptor (sodium/taurocholate cotransporting polypeptide, NTCP) toward IFNα-responsive cells using epigenetic reprogramming. Herein, we showed that an epigenetic regimen with non-cytotoxic doses of the demethylating compound 5-azacytidine restored the anti-HBV action of IFNα in epigenetically reprogrammed HepG2-NTCP-C4 cells, named REP-HepG2-NTCP cells. Thus, a significant inhibition in HBV DNA levels was measured in REP-HepG2-NTCP cells after IFNα treatment. This inhibitory effect was associated with the enhancement of IFNα-mediated induction of critical interferon-stimulated genes (ISGs), which was limited in non-reprogrammed cells. In particular, our data indicated that re-expression of 2’-5’-oligoadenylate synthetase 1 (OAS1) and interferon regulatory factor 9 (IRF9) was the result of an epigenetically driven unmasking of these genes in reprogrammed cells. At last, we evaluated the therapeutic potential of the IFN analog CDM-3008 in REP-HepG2-NTCP cells and demonstrated the efficiency of this chemical compound in triggering ISG induction and HBV inhibition. In summary, this study shows that epigenetic reprogramming promotes the IFNα response in HBV-infected cells and is potentially attractive for cell-based experimental screening of IFN-like compounds.

Non-Genomic Control of Dynamic MYCN Gene Expression in Liver Cancer

Upregulated MYCN gene expression is restricted to specialized cell populations such as EpCAM⁺ cancer stem cells in liver cancer, regardless of DNA amplification and mutation. Here, we reviewed the role of MYCN gene expression in liver homeostasis, regeneration, and tumorigenesis, and discussed the potential non-genomic mechanisms involved in controlling MYCN gene expression in liver cancer, with a focus on inflammation-mediated signal transduction and microRNA-associated post-transcriptional regulation. We concluded that dynamic MYCN gene expression is an integrated consequence of multiple signals in the tumor microenvironment, including tumor growth-promoting signals, lipid desaturation-mediated endoplasmic reticulum stress adaptation signals, and tumor suppressive miRNAs, making it a potential predictive biomarker of tumor stemness and plasticity. Therefore, understanding and tracing the dynamic changes and functions of MYCN gene expression will shed light on the origin of liver tumorigenesis at the cellular level and the development of novel therapeutic and diagnostic strategies for liver cancer treatment.

Transcriptome Analysis of Ivosidenib-Mediated Inhibitory Functions on Non-Small Cell Lung Cancer

Ivosidenib is an isocitrate dehydrogenase mutant inhibitor that the US Food and Drug Administration recently approved for the treatment of leukemia. Studies suggested that ivosidenib may inhibit the progression of non-small cell lung cancer (NSCLC). In the present study, we explored RNAs and their potential regulatory mechanisms by which ivosidenib treats NSCLC cells. We used MTT assays, Transwell assays, and flow cytometry to measure the anti-tumor effects of ivosidenib in NSCLC cells. We performed whole transcriptome sequencing to determine differentially expressed mRNAs (DE-mRNAs) and non-coding RNAs (ncRNA). We used GO and KEGG pathway enrichment analyses to identify the functions and potential mechanisms. According to miRNA target interactions, we constructed a competing endogenous network. Ivosidenib inhibited the proliferation, invasion, and migration of NSCLC cells and inhibited tumor growth in vivo. We identified 212 DE-mRNAs, four DE-miRNAs, and 206 DE-lncRNAs in ivosidenib-treated NSCLC cells compared to untreated NSCLC cells. DE-mRNAs were significantly enriched in the cancer-associated pathways, including the TGF-β signaling pathway, the PI3K-Akt signaling pathway, the Jak-STAT signaling pathway, the MAPK signaling pathway, the Rap1 signaling pathway, and cell adhesion molecules. Based on the competing endogenous RNA hypothesis, we constructed lncRNA-miRNA-mRNA networks to elucidate the regulatory relationships between mRNA and ncRNA. We found that qRT-PCR results showed corresponding expression trends of differential genes with sequencing data. Our results provide insights into the molecular basis of ivosidenib suppression of NSCLC.

Potential targets and molecular mechanism of miR-331-3p in hepatocellular carcinoma identified by weighted gene coexpression network analysis

Hepatocellular carcinoma (HCC) is one of the most common malignant tumor. miR-331-3p has been reported relevant to the progression of HCC, but the molecular mechanism of its regulation is still unclear. In the study, we comprehensively studied the role of miR-331-3p in HCC through weighted gene coexpression network analysis (WGCNA) based on The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Oncomine. WGCNA was applied to build gene co-expression networks to examine the correlation between gene sets and clinical characteristics, and to identify potential biomarkers. Five hundred one target genes of miR-331-3p were obtained by overlapping differentially expressed genes (DEGs) from the TCGA database and target genes predicted by miRWalk. The critical turquoise module and its eight key genes were screened by WGCNA. Enrichment analysis was implemented based on the genes in the turquoise module. Moreover, 48 genes with a high degree of connectivity were obtained by protein–protein interaction (PPI) analysis of the genes in the turquoise module. From overlapping genes analyzed by WGCNA and PPI, two hub genes were obtained, namely coatomer protein complex subunit zeta 1 (COPZ1) and elongation factor Tu GTP binding domain containing 2 (EFTUD2). In addition, the expression of both hub genes was also significantly higher in tumor tissues compared with normal tissues, as confirmed by analysis based on TCGA and Oncomine. Both hub genes were correlated with poor prognosis based on TCGA data. Receiver operating characteristic (ROC) curve validated that both hub genes exhibited excellent diagnostic efficiency for normal and tumor tissues.

MicroRNA signature in liver cancer

Liver cancer is the 7^th utmost frequent neoplasm and the 4^th principal source of cancer deaths. This malignancy is linked with several environmental and lifestyle-related factors emphasizing the role of epigenetics in its pathogenesis. MicroRNAs (miRNAs) have been regarded as potent epigenetic mechanisms partaking in the pathogenesis of liver cancer. Dysregulation of miRNAs has been related with poor outcome of patients with liver cancer. In the current manuscript, we provide a concise review of the results of recent studies about the role of miRNAs in the progression of liver cancer and their diagnostic and prognostic utility.

Silencing of Long Non-Coding RNA FGD5-AS1 Inhibits the Progression of Non-Small Cell Lung Cancer by Regulating the miR-493-5p/DDX5 Axis

Background:

Long non-coding RNA FGD5 antisense RNA 1 (FGD5-AS1), identified to be a carcinogenic lncRNA, exhibits a regulatory role in some malignancies including non-small cell lung cancer (NSCLC). The aim of the present research is to decipher the function and underlying mechanism of FGD5-AS1 in progression of NSCLC.

Methods:

Expression of FGD5-AS1, miR-493-5p and DEAD-box protein 5 (DDX5) in NSCLC tissues and cells was quantified utilizing qRT-PCR. Cell proliferation was assessed by CCK-8 method. Scratch healing test and Transwell assay were used for assaying cell migration and invasion. Expressions of DDX5 and epithelial-mesenchymal transition (EMT)-related proteins were examined by Western blot. Additionally, targeting relationships between FGD5-AS1 and miR-493-5p, miR-493-5p and DDX5 were verified by dual-luciferase reporter gene assay.

Results:

Expression of FGD5-AS1 in NSCLC tissues and cell lines was up-regulated. Expression of FGD5-AS1 was in association with enlarged tumor size and lymph node metastasis of the patients. Knockdown of FGD5-AS1 led to the inhibition of proliferation, migration, invasion and EMT of NSCLC cells. FGD5-AS1 directly targeted miR-493-5p, while DDX5 was the target of miR-493-5p in NSCLC cells. Additionally, FGD5-AS1 could positively regulate the expression of DDX5 via suppressing miR-493-5p.

Conclusion:

FGD5-AS1 facilitates the proliferation, migration, invasion and EMT of NSCLC cells by sponging miR-493-5p and up-regulating DDX5.

High expression of IGF2-derived intronic miR-483 predicts outcome in hepatoblastoma

BACKGROUND

The role of microRNAs (miRs) as biomarkers to predict outcome in hepatoblastoma (HB), the most common malignant liver tumor in childhood, has still to be determined. Recently, the so-called four-miR signature has been described to efficiently stratify HB patients according to their prognosis.

OBJECTIVE

We examined the recently described four-miR signature for its clinical relevance in an independent validation cohort of HB patients and tried to optimize its predictive value by analyzing four additional miRs involved in HB biology.

METHODS

Expression of eight miR was determined in 29 tumor and 10 normal liver samples by TaqMan assays and association studies and Kaplan-Meier estimators determined their clinical relevance.

RESULTS

Stratifying HB patients by the four-miR signature showed no difference in patients' outcome, which was also reflected by the lack of association with any clinical risk parameter. Adding miR-23b-5p and miR-23b-3p did also not increase its discriminating power. However, the integration of miR-483-5p and miR-483-3p into the four-miR signature could predict patients with poor outcome that were associated with large tumors and vessel invasive growth with high accuracy.

CONCLUSIONS

The expansion of the four-miR signature by miR-483 serves as a useful biomarker to predict outcome of HB patients.

High glucose inhibits osteogenic differentiation of bone marrow mesenchymal stem cells via regulating miR-493-5p/ZEB2 signalling

Diabetic osteoporosis (DOP) is attributed to the aberrant physiological function of bone marrow mesenchymal stem cells (BMSCs) under high glucose (HG) environment. MicroRNAs (miRNAs) are involved in the pathological processes of DOP. We aimed to explore the underlying mechanism of miRNA in DOP. BMSCs were cultured in osteogenic medium with HG to induce osteogenic differentiation, and the interaction between miR-493-5p and ZEB2 was assessed by luciferase assay. Herein, we found miR-493-5p is gradually reduced during osteogenic differentiation in BMSCs. HG treatment inhibits osteogenic differentiation and induces an up-regulation of miR-493-5p leading to reduced level of its downstream target ZEB2. Inhibition of miR-493-5p attenuates HG-induced osteogenic differentiation defects by upregulation of ZEB2. Mechanistically, miR-493-5p/ZEB2 signalling mediates HG-inhibited osteogenic differentiation by inactivation of Wnt/β-catenin signalling. More importantly, knockdown of miR-493-5p therapeutically alleviated the DOP condition in mice. HG prevents BMSCs osteogenic differentiation via up-regulation of miR-493-5p, which results in reduced level of ZEB2 by directly targeting its 3'-untranslated region of mRNA. Thus, miR-493-5p/ZEB2 is a potential therapeutic target and provides novel strategy for the treatment and management of DOP.

Exosomal linc-FAM138B from cancer cells alleviates hepatocellular carcinoma progression via regulating miR-765

Exosomes are small vesicles with a diameter of 30-150 nm secreted by cells, which can be used as signal carriers to transfer nucleic acids, proteins, lipids and other functional substances to the recipient cells and play a role in cell communication. Hepatocellular carcinoma is the fourth most common cause of cancer-related death worldwide. Studies have shown that long non-coding RNAs (lncRNAs) are involved in the development and progression of many types of tumors. Our present study found that linc-FAM138B was reduced in HCC tissues and cell lines, low expression of linc-FAM138B indicated a poor prognosis in HCC patients. Interestingly, linc-FAM138B could be packaged into cancer cells. And exo-FAM138B inhibited the proliferation, migration and invasion of HCC cells. Furthermore, linc-FAM138B sponged miR-765 levels. And exo-si-FAM138B promoted HCC progression, while deletion of miR-765 reversed the role of exo-si-FAM138B. In vivo tumorigenesis experiments showed that exo-FAM138B suppressed HCC growth via modulating miR-765. In conclusion, exo-linc-FAM138B secreted by cancer cells inhibited HCC development via targeting miR-765, which provided a new idea and perspective for in-depth understanding of the complex signal regulation in HCC process.

Lung cancer‑associated transcript 1 facilitates tumorigenesis in laryngeal squamous cell carcinoma through the targeted inhibition of miR‑493

Long non-coding RNAs (lncRNAs) serve important roles in the tumorigenesis of a diverse range of cancer types. The lung cancer-associated transcript 1 (LUCAT1), has been reported to promote the proliferation, migration and invasion of oral squamous cell carcinoma cells. However, the exact role of LUCAT1 in laryngeal squamous cell carcinoma (LSCC) remains to fully understood. The present study aimed to interrogate the role and modulatory mechanism of LUCAT1 in LSCC. Reverse transcription-quantitative PCR and western blotting were used to investigate the expression of LUCAT1 and miR-493, as well as the protein expression of cyclin-dependent kinase 2, cyclin E1, p21, matrix metalloproteinase (MMP)2, MMP9, vascular endothelial growth factor-C, Bcl-2, Bax, cleaved caspase-3 and procaspase-3. Cell Counting Kit-8, flow cytometry, wound healing and Transwell assays were performed to analyze the proliferation, cell cycle, apoptosis levels, and the migratory and invasive abilities, respectively, of the LSCC AMC-HN-8 cell line. In addition, dual-luciferase reporter and ribonucleoprotein immunoprecipitation assays were used to investigate the binding between LUCAT1 and microRNA (miR)-493. The results of the present study revealed that the expression levels of LUCAT1 were upregulated in AMC-HN-8 cells. The genetic knockdown of LUCAT1 expression levels significantly suppressed the cell proliferation, alongside downregulating the expression levels of CDK2 and cyclin E1 and upregulating p21 expression levels. In addition, the knockdown of LUCAT1 inhibited cell migration and invasion, as demonstrated using the wound healing and Transwell assays, respectively. Moreover, LUCAT1 knockdown promoted cell apoptosis and upregulated the expression levels of Bax and cleaved caspase-3, whilst downregulating the expression levels of Bcl-2. Furthermore, LUCAT1 was discovered to directly bind to and inhibit the well-known tumor suppressor, miR-493. Notably, the specific inhibition of miR-493 partly blocked the anticancer effects of LUCAT1 knockdown in AMC-HN-8 cells. In conclusion, these results suggested that LUCAT1 may facilitate tumorigenesis in LSCC through the targeted inhibition of miR-493, which provides evidence for a novel target for the treatment of LSCC.

miR-34a-5p suppresses the invasion and metastasis of liver cancer by targeting the transcription factor YY1 to mediate MYCT1 upregulation

BACKGROUND

In recent years, microRNAs (miRNAs) are reported to act as molecular biomarkers for cancer diagnosis, treatment, and prognosis (including liver cancer) and to be involved in the development and progression of cancer and other physiological and pathological changes. However, the role of miR-34a-5p in liver cancer is still largely unknown.

METHODS

In our study, the expression of miR-34a-5p in liver cancer tissues and HCC cell lines was detected by qRT-PCR. The CCK-8, scratch wound-healing motility and Transwell assays were used to evaluate the effect on cell proliferation, migration and invasion. The expression of YY1, E-cadherin, N-cadherin and vimentin was analysed by western blotting. The dual luciferase assay was performed to confirm whether YY1 is a target of miR-34a-5p. The combination of YY1 and MYCT1 was detected by chromatin immunoprecipitation (ChIP) assay.

RESULTS

The results showed that miR-34a-5p was downregulated in liver cancer tissues and HCC cell lines. Overexpression of miR-34a-5p inhibited the proliferation, migration and invasion of liver cancer cells. YY1 was a direct target of miR-34a-5p, and the expression of YY1 could reverse the influence of miR-34a-5p on the proliferation, migration and invasion of liver cancer cells. YY1 inhibited MYCT1 expression by directly binding to its promoter region, and knockdown of MYCT1 reversed the influence of miR-34a-5p on the proliferation, migration and invasion of liver cancer cells.

CONCLUSION

Our results suggest that miR-34a-5p could inhibit the invasion and metastasis of hepatoma cells by targeting YY1-mediated MYCT1 transcriptional repression.

The role of noncoding RNAs in epithelial cancer

Regulatory noncoding RNAs (ncRNAs) are a class of RNAs transcribed by regions of the human genome that do not encode for proteins. The three main members of this class, named microRNA, long noncoding RNA, and circular RNA play a key role in the regulation of gene expression, eventually shaping critical cellular processes. Compelling experimental evidence shows that ncRNAs function either as tumor suppressors or oncogenes by participating in the regulation of one or several cancer hallmarks, including evading cell death, and their expression is frequently deregulated during cancer onset, progression, and dissemination. More recently, preclinical and clinical studies indicate that ncRNAs are potential biomarkers for monitoring cancer progression, relapse, and response to cancer therapy. Here, we will discuss the role of noncoding RNAs in regulating cancer cell death, focusing on those ncRNAs with a potential clinical relevance.

The IGF-II-Insulin Receptor Isoform-A Autocrine Signal in Cancer: Actionable Perspectives

Insulin receptor overexpression is a common event in human cancer. Its overexpression is associated with a relative increase in the expression of its isoform A (IR^A), a shorter variant lacking 11 aa in the extracellular domain, conferring high affinity for the binding of IGF-II along with added intracellular signaling specificity for this ligand. Since IGF-II is secreted by the vast majority of malignant solid cancers, where it establishes autocrine stimuli, the co-expression of IGF-II and IR^A in cancer provides specific advantages such as apoptosis escape, growth, and proliferation to those cancers bearing such a co-expression pattern. However, little is known about the exact role of this autocrine ligand–receptor system in sustaining cancer malignant features such as angiogenesis, invasion, and metastasis. The recent finding that the overexpression of angiogenic receptor kinase EphB4 along with VEGF-A is tightly dependent on the IGF-II/IR^A autocrine system independently of IGFIR provided new perspectives for all malignant IGF2omas (those aggressive solid cancers secreting IGF-II). The present review provides an updated view of the IGF system in cancer, focusing on the biology of the autocrine IGF-II/IR^A ligand–receptor axis and supporting its underscored role as a malignant-switch checkpoint target.

MicroRNA-493-5p-mediated repression of the MYCN oncogene inhibits hepatic cancer cell growth and invasion

Primary hepatic tumors mainly include hepatocellular carcinoma (HCC), which is one of the most frequent causes of cancer‐related deaths worldwide. Thus far, HCC prognosis has remained extremely poor given the lack of effective treatments. Numerous studies have described the roles played by microRNAs (miRNAs) in cancer progression and the potential of these small noncoding RNAs for diagnostic or therapeutic applications. The current consensus supports the idea that direct repression of a wide range of oncogenes by a single key miRNA could critically affect the malignant properties of cancer cells in a synergistic manner. In this study, we aimed to investigate the oncogenes controlled by miR‐493‐5p, a major tumor suppressor miRNA that inactivates miR‐483‐3p oncomir in hepatic cancer cells. Using global gene expression analysis, we highlighted a set of candidate genes potentially regulated by miR‐493‐5p. In particular, the canonical MYCN protooncogene (MYCN) appeared to be an attractive target of miR‐493‐5p given its significant inhibition through 3′‐UTR targeting in miR‐493‐5p‐rescued HCC cells. We showed that MYCN was overexpressed in liver cancer cell lines and clinical samples from HCC patients. Notably, MYCN expression levels were inversely correlated with miR‐493‐5p in tumor tissues. We confirmed that MYCN knockdown mimicked the anticancer effect of miR‐493‐5p by inhibiting HCC cell growth and invasion, whereas MYCN rescue hindered miR‐493‐5p activity. In summary, miR‐493‐5p is a pivotal miRNA that modulates various oncogenes after its reexpression in liver cancer cells, suggesting that tumor suppressor miRNAs with a large spectrum of action could provide valuable tools for miRNA replacement therapies.

MicroRNA-1251-5p promotes tumor growth and metastasis of hepatocellular carcinoma by targeting AKAP12

MicroRNAs (miRNA) are small RNA molecules that have emerged as important regulators of gene expression in hepatocellular carcinoma (HCC). However, the expression, function and mechanism of miR-1251-5p in HCC remain poorly understood. In the present study, it was observed that miR-1251-5p expression was upregulated in HCC. Furthermore, higher miR-1251-5p level was correlated with poor prognosis, large tumor size, vascular invasion and high tumor-node-metastasis (TNM) stages of HCC patients. Functionally, miR-1251-5p drove HCC cell proliferation, migration and invasion in vitro, and promoted growth and metastasis of HCC cells in vivo. A-kinase anchor protein 12 (AKAP12) was screened as a direct target of miR-1251-5p by using the starBase V3.0 online platform. The AKAP12 mRNA expression was downregulated and negatively correlated with miR-1251-5p level in HCC tissues. Furthermore, in vitro experiments confirmed that AKAP12 was targeted and negatively regulated by miR-1251-5p. Importantly, AKAP12 overexpression decreased HCC cell proliferation, migration and invasion, whereas inhibition of AKAP12 rescued the miR-1251-5p knockdown-attenuated HCC cell proliferation, migration and invasion. Overall, the present study indicates that miR-1251-5p plays an oncogenic role in HCC by targeting AKAP12, and may be a potential therapeutic target for HCC treatment.

LncRNA GAS6-AS2 facilitates tumor growth and metastasis of hepatocellular carcinoma by activating the PI3K/AKT/FoxO3a signaling pathway

The morbidity and mortality of hepatocellular carcinoma (HCC) are growing yearly. Several reports emphasize the importance of long non-coding RNAs (lncRNAs) in HCC. This paper provides a molecular mechanism for the function of GAS6-AS2 in HCC. The expressions of GAS6-AS2, miR-493-5p and OTUB1 were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration, and invasion were measured by cell counting kit-8 (CCK-8), flow cytometry and transwell assay, respectively. The interaction of miR-493-5p and GAS6-AS2 or OTU domain-containing Ubiquitin Aldehyde-binding Protein 1 (OTUB1) was analyzed by starBase v2.0 and verified by luciferase reporter assay. The protein level of OTUB1 as well as PI3K, p-PI3K, AKT, p-AKT, FoxO3a, p-FoxO3a and β-actin protein levels were distinguished by western blot. GAS6-AS2 was up-regulated in HCC tissues and cells. GAS6-AS2 knockdown inhibited proliferation, migration, and invasion but promoted apoptosis. MiR-493-5p, a target of GAS6-AS2, was down-regulated in HCC tissues and cells. Inhibition of miR-493-5p reversed the effects of GAS6-AS2 knockdown on HCC cells. OTUB1, a target of miR-493-5p, was up-regulated in HCC cells and its expression was modulated by miR-493-5p. Overexpression of OTUB1 recovered the positive effects of miR-493-5p enrichment or GAS6-AS2 knockdown on HCC cells. GAS6-AS2 knockdown impeded the activation of PI3K/AKT/FoxO3a signaling pathway, while this activation was reversed by miR-493-5p inhibition or OTUB1 overexpression. In conclusion, GAS6-AS2 knockdown suppressed proliferation, migration, and invasion but promoted apoptosis of HCC cells by impeding PI3K/AKT/FoxO3a signaling pathway through regulating the GAS6-AS2/miR-493-5p/OTUB1 axis.

Chelidonine enhances the antitumor effect of lenvatinib on hepatocellular carcinoma cells

Background

Lenvatinib is a newly approved molecular targeted drug for the treatment of advanced hepatocellular carcinoma (HCC). However, the high cost associated with this treatment poses a huge financial burden on patients and the entire public health system. Therefore, there is an urgent need to develop novel strategies that enhance the antitumor effect of lenvatinib.

Methods

The antitumor effects of chelidonine or/and lenvatinib on HCC cell lines MHCC97-H and LM-3 were examined using the 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2- H-tetrazolium bromide (MTT) assay. For the in-vivo investigation, the effect on subcutaneous or intrahepatic tumor growth in nude mice was also determined. The mRNA levels of epithelial mesenchymal transition (EMT)-related factors were examined through quantitative polymerase chain reaction or Western blot.

Results

In the present study, we found that treatment with chelidonine enhanced the apoptotic effect of lenvatinib on HCC cells and the in-vivo growth of HCC tumors in nude mice. Mechanistically, treatment with chelidonine increased the expression of epithelial indicator E-cadherin, whereas it decreased the expression of mesenchymal indicators N-cadherin and Vimentin. These findings suggest that chelidonine restricted the EMT in HCC cells.

Conclusion

Chelidonine inhibits the process of EMT and enhances the antitumor effect of lenvatinib on HCC cells.