Circular RNA circVAPA Promotes Cell Proliferation in Hepatocellular Carcinoma.

Circular RNAs (circRNAs), continuous loops of single-stranded RNA, regulate gene expression during the development of various cancers. However, the function of circRNAs in hepatocellular carcinoma (HCC) is rarely discussed. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the mRNA levels of circ_0011385, miR-361-3p, and STC2 in 96 pairs of HCC tissues (tumor tissues and adjacent normal tissues), HCC cell lines, and L02 (human normal liver cell line) cells. The relationships between circ_0011385 expression and clinical features of HCC were evaluated. Functional experiments in vitro or in vivo were used to evaluate the biological function of circ_0011385. Bioinformatics analysis was performed to predict miRNAs and mRNAs sponged by circ_0011385. RNA immunoprecipitation (RIP) and dual-luciferase reporter gene assays were used to elucidate the interactions among circ_0011385, miR-361-3p, and STC2 (stanniocalcin 2). ChIP and dual-luciferase reporter gene assays were used to identify the upstream regulator of circ_0011385. High expression of circ_0011385 was observed in HCC tissues and cell lines and was significantly associated with tumor size, TNM stage, and prognosis. In addition, inhibition of circ_0011385 expression prevented the proliferation of HCC cells in vitro and in vivo. Circ_0011385 sponged miR-361-3p, thereby regulating the mRNA expression of STC2. In addition, the transcription of circ_0011385 was regulated by SP3. Circ_0011385 knockdown suppressed cell proliferation and tumor activity in HCC. Circ_0011385 may therefore serve as a new biomarker in the diagnosis and treatment of HCC.

To investigate whether Tg737 is regulated by microRNA-548a-5p (miR-548a-5p), and correlates with hepatocellular carcinoma (HCC) cell proliferation and apoptosis. Assays of loss of function of Tg737 were performed by the colony formation assay, CCK assay and cell cycle assay in HCC cell lines. The interaction between miR-548a-5p and its downstream target, Tg737, was evaluated by a dual-luciferase reporter assay and quantitative real-time polymerase chain reaction. Tg737 was then up-regulated in HCC cells to evaluate its effect on miR-548a-5p regulation. HepG2 cells stably overexpressing miR-548a-5p or miR-control were also subcutaneously inoculated into nude mice to evaluate the effect of miR-548a-5p up-regulation on in vivo tumor growth. As the final step, the effect of miR-548a-5p on the apoptosis induced by cisplatin was evaluated by flow cytometry. Down-regulation of Tg737, which is a target gene of miR-548a-5p, accelerated HCC cell proliferation, and miR-548a-5p promoted HCC cell proliferation in vitro and in vivo. Like the down-regulation of Tg737, overexpression of miR-548a-5p in HCC cell lines promoted cell proliferation, increased colony forming ability and hampered cell apoptosis. In addition, miR-548a-5p overexpression increased HCC cell growth in vivo. MiR-548a-5p down-regulated Tg737 expression through direct contact with its 3' untranslated region (UTR), and miR-548a-5p expression was negatively correlated with Tg737 levels in HCC specimens. Restoring Tg737 (without the 3'UTR) significantly hampered miR-548a-5p induced cell proliferation, and rescued the miR-548a-5p induced cell proliferation inhibition and apoptosis induced by cisplatin. MiR-548a-5p negatively regulates the tumor inhibitor gene Tg737 and promotes tumorigenesis in vitro and in vivo, indicating its potential as a novel therapeutic target for HCC.

Circular RNAs (circRNAs) are key regulators in hepatocellular carcinoma (HCC) tumorigenesis and development, yet it is unclear whether circ-CCND1 participates in regulating HCC progression. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed for detecting the expressions of circ-CCND1, microRNA (miR) -497-5p, and high mobility group AT-hook 2 (HMGA2) mRNA in HCC tissues and cell lines. Subcellular fractionation assay was used to analyze the localization of circ-CCND1 in HCC cell lines. Loss-of-function experiments were conducted to examine the effects of circ-CCND1 on HCC cell proliferation, migration, and invasion. Dual-luciferase reporter gene assay was employed for detecting the targeting relationships of circ-CCND1 and miR-497-5p, as well as miR-497-5p and HMGA2, respectively. Western blot was used to detect the regulatory functions of circ-CCND1 and miR-497-5p on HMGA1 expression at protein level. Circ-CCND1 and HMGA2 expressions in HCC were significantly up-regulated and miR-497-5p expression was markedly decreased. High circ-CCND1 expression was associated with relatively large tumor size and lymph node metastasis in HCC patients. In addition, circ-CCND1 was mainly distributed in the cytoplasm of HCC cells. Functionally, knockdown of circ-CCND1 remarkably suppressed HCC cell proliferation, migration, and invasion. Mechanistically, miR-497-5p was a direct target of circ-CCND1 and miR-497-5p specifically modulated HMGA2 expression. Furthermore, miR-497-5p inhibitors and or HMGA2 overexpression partially counteracted the suppressing effect induced by si-circ-CCND1 on the malignant phenotype of HCC cells. Circ-CCND1 plays a cancer-promoting role in HCC by modulating the miR-497-5p/HMGA2 axis. Therefore, targeting circ-CCND1 is likely to be a promising therapeutic strategy for HCC.

BACKGROUNDIt is critical to explore effective therapeutic targets for improving the survival rate of patients with hepatocellular carcinoma (HCC). Although many studies have focused on flotillin-1 (FLOT1) as a lipid raft-associated protein that regulates the activation of some proteins or kinases to promote tumor cell survival and proliferation, few studies have explored the regulation of Golgi apparatus function.AIMTo investigate the molecular mechanism through which FLOT1 activates the Golgi stress response downstream of transcription factor E3 (TFE3), thereby promoting the progression of HCC.METHODSFLOT1 expression in HCC tissue, HCC cell lines, and nude mouse tumor models was assessed. The impact of FLOT1 silencing or its overexpression on the proliferation of HCC cells was studied. CCK-8, flow cytometry, and transwell assays were used to assess the proliferation, cell cycle, migration, and invasion abilities of HCC cells. A dual-luciferase reporter assay was used to study the effect of FLOT1 on the transcriptional activity of the downstream Golgi apparatus stress element promoter of TFE3. Western blotting, co-immunoprecipitation, and immunofluorescence staining were employed to detect relevant proteins.RESULTSHigh FLOT1 expression was correlated with a poor prognosis in patients with HCC. The knockdown of FLOT1 suppressed the proliferation, migration, and invasion of HCC cells and promoted their apoptosis. Xenograft assays revealed that FLOT1 knockdown inhibited HCC tumorigenesis in vivo. Mechanistically, FLOT1 inhibited the expression of mechanistic target of rapamycin complex 1/2 proteins through ubiquitination and downstream effector p-S6 kinase-T389, leading to the dephosphorylation and nuclear translocation of TFE3 and promotion of Golgi stress-mediated responses, ultimately resulting in HCC progression.CONCLUSIONFLOT1 recruits and inhibits mechanistic target of rapamycin complex 1/2, causing dephosphorylation and TFE3 nuclear translocation, thereby activating the Golgi stress response and further promoting the proliferation, migration, and invasion capabilities of HCC cells. These results underscore the potential of FLOT1 as a promising therapeutic target for HCC.

ZNF382 inhibits hepatocellular carcinoma (HCC) cell proliferation and motility and induces apoptosis by up-regulating SOX11

Liver cancer, the second most commonly diagnosed cancer, is associated with high mortality rates. E2F4 is a member of the E2F transcription factor family. There are limited studies on the role of E2F4 in hepatocellular carcinoma (HCC). In this study, the expression of E2F4 in HCC tissue samples and cell lines was analyzed using quantitative real-time polymerase chain reaction. E2F4 expression positively correlated with tumor size in patients with HCC. Additionally, E2F4 expression was greater in HCC cells than in normal LO2 cells. Furthermore, overexpression of E2F4 significantly enhanced the proliferation, migration, and invasion of HCC cells. The results of a luciferase assay revealed that E2F4 upregulated the expression of CDCA3 by binding to its promoter region (1863'-ACGCGCGAGAATG-1875') and consequently promoted proliferation and cell cycle progression of HCC cells. Taken together, these results demonstrated that E2F4 might play a vital role in HCC progression and could serve as a potential biomarker for the diagnosis and as a therapeutic target of HCC.

ObjectivesThe aim of this study is to elucidate the functional mechanism of the miRNA-424-5p/CHEK1 pathway in hepatocellular carcinoma (HCC), thereby offering novel insights for the development of targeted therapeutic strategies for HCC. MethodsWe employed a combination of bioinformatics analysis and data from the GEO to construct a regulatory network between miRNA and mRNA. Real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to assess the expression levels of miR-424-5p and CHEK1. Protein expression of CHEK1 was determined using Western blot analysis. The targeting relationship between miR-424-5p and CHEK1 was validated through a dual-luciferase reporter assay. Furthermore, the effects of miR-424-5p on HCC cell proliferation, migration, and invasion were evaluated using the Cell Counting Kit-8 assay, wound healing assay, and Transwell invasion assay, respectively. Apoptosis of HCC cells was measured by flow cytometry. ResultsBioinformatics analysis revealed that miR-424-5p was significantly downregulated, while CHEK1 was upregulated respectively in GEO dataset. Furthermore, this inverse expression pattern was observed in both HCC tissues and cell lines. Specifically, downregulation of miR-424-5p was found to promote the proliferation, migration, and invasion of HCC cells, while also inhibiting their apoptosis. The dual-luciferase reporter assay confirmed a direct targeting relationship between miR-424-5p and CHEK1. Inhibition of miR-424-5p was shown to counteract the suppressive effects on HCC cell proliferation, migration, and invasion that result from CHEK1 silencing. Additionally, experimental verification indicated that the activation of the cell cycle pathway is implicated in the oncogenic function of miR-424-5p/CHEK1 in HCC. ConclusionsThe present study demonstrates that miR-424-5p exerts a suppressive effect on HCC cell proliferation, migration, and invasion by downregulating the expression of CHEK1. This finding may offer a theoretical foundation for improving the prognosis and developing novel therapeutic strategies for HCC patients.

Background/Aims: Previous studies have demonstrated that long non-coding RNAs (lncRNAs) may play critical roles in cancer biology, including Hepatocellular carcinoma (HCC). The HOXA cluster antisense RNA2 (HOXA-AS2) lncRNA plays an important role in carcinogenesis, however, the underlying role of HOXA-AS2 in HCC remains unknown. The present study examined the effects of HOXA-AS2 on the progression of HCC, and explored the underlying molecular mechanisms. Methods: Quantitative real-time PCR was used to detect HOXA-AS2 expression in HCC tissues and cell lines. Furthermore, the effects of HOXA-AS2 silencing and overexpression on cell proliferation, cell cycle, apoptosis, migration, and invasion were assessed in HCC in vitro and in vivo. Furthermore, bioinformatics online programs predicted and luciferase reporter assay were used to validate the association of HOXA-AS2 and miR-520c-3p in HCC cells. Results: We observed that HOXA-AS2 was up-regulated in HCC tissues and cell lines. In vitro experiments revealed that HOXA-AS2 knockdown significantly inhibited HCC cells proliferation by causing G1 arrest and promoting apoptosis, whereas HOXA-AS2 overexpression promoted cell growth. Further functional assays indicated that HOXA-AS2 significantly promoted HCC cell migration and invasion by promoting EMT. Bioinformatics online programs predicted that HOXA-AS2 sponge miR-520c-3p at 3’-UTR with complementary binding sites, which was validated using luciferase reporter assay. HOXA-AS2 could negatively regulate the expression of miR-520c-3p in HCC cells. MiR-520c-3p was down-regulated and inversely correlated with HOXA-AS2 expression in HCC tissues. miR-520c-3p suppressed cell proliferation, invasion and migration in HCC cells, and enforced expression of miR-520c-3p attenuated the oncogenic effects of HOXA-AS2 in HCC cells. By bioinformatic analysis and dual-luciferase reporter assay, we found that miR-223-3p directly targeted the 3’-untranslated region (UTR) of Glypican-3 (GPC3), one of the key players in HCC. GPC3 was up-regulated in HCC tissues, and was negatively correlated with miR-520c-3p expression and positively correlated with HOXA-AS2 expression. Conclusion: In summary, our results suggested that the HOXA-AS2/miR-520c-3p/GPC3 axis may play an important role in the regulation of PTC progression, which could serve as a biomarker and therapeutic target for HCC.

To investigate the molecular mechanism through which calenduloside E inhibits hepatocellular carcinoma (HCC) cell proliferation and migration. HCC cell lines HepG2 and Huh7 treated with calenduloside E were examined for changes in cell viability using CCK-8 assay and expressions of GPX4, SLC7A11, LC3, P62 and phosphorylation of Akt/mTOR using Western blotting. The effects LY294002 and Rapamycin (the inhibitor and activator of autophagy, respectively) on proliferation and migration of calenduloside E-treated HCC cells were evaluated using EdU and Transwell assays. The TCGA database was used to explore the expression levels of GPX4 and SLC7A11 in HCC and normal liver tissues and their correlation with the patients'survival outcomes. GPX4 and SLC7A11 expressions were also detected in HCC cells and normal hepatocytes using RT-qPCR and Western blotting. Calenduloside E obviously inhibited the viability of HCC cells. GPX4 and SLC7A11 were highly expressed in HCC tissues and cell lines, and their expression levels were negatively correlated with the patients'survival. In HCC cell lines, calenduloside E significantly inhibited the expressions of GPX4 and SLC7A11 proteins, activated the Akt-mTOR pathway, and enhanced the expression of LC3 Ⅱ. The inhibitory effect of calenduloside E on GPX4 and SLC7A11 expressions was significantly enhanced by rapamycin but attenuated by LY294002. Inhibiting the autophagy pathway obviously diminished the inhibitory effect of calenduloside E on proliferation and migration of HCC cells, while activating this pathway produced the opposite effect. Calenduside E inhibits the proliferation and migration of HCC cells by down-regulating GPX4 and SLC7A11 expression via the autophagy pathway.

Long noncoding RNA Loxl1-As1 promotes cell apoptosis and suppresses cell proliferation in hepatocellular carcinoma in vitro

Reduced Expression of Fibroblast Growth Factor Receptor 2IIIb in Hepatocellular Carcinoma Induces a More Aggressive Growth

BackgroundCircular RNAs (circRNAs) could interact with miRNAs to regulate gene expression, participating in hepatocellular carcinoma (HCC) initiation and development. This work aimed to determine the potential function and molecular mechanism of circEPB41L2 (hsa_circ_0077837) during HCC progression.Materials and MethodsThe expression of circEPB41L2 in HCC tissues and HCC cell lines was quantified using real-time quantitative PCR (qRT-PCR). CCK-8 assays and colony formation assays were utilized to detect the proliferation of HCC cells. Wound healing assay and transwell assay were performed to determine the capability of migration and invasion for HCC cells. Western blot was conducted to determine gene expression on protein levels. The effect of circEPB41L2 on HCC in vivo was investigated via xenograft experiment. Interaction between circEPB41L2 and miR-590-5p was predicted through bioinformatics methods and confirmed via luciferase reporter assay.ResultsExtensive analysis of circRNA profiles in tumor and matched para-tumor tissues collected from 61 HCC patients identified that circEPB41L2 was significantly down-regulated in HCC, which was further confirmed in another HCC group by qRT-PCR analysis. The clinicopathological analysis revealed that down-regulation of circEPB41L2 was negatively associated with tumor size, vascular invasion and alpha-fetoprotein, while positively correlated with HCC prognosis. The biological function experiments showed that overexpression of circEPB41L2 could obviously inhibit the proliferation and metastasis of HCC cells in vitro, while knockdown of circEPB41L2 induced opposite results. Moreover, we also found that circEPB41L2 inhibited HCC migration and invasion though EMT signaling pathway. Similarly, overexpression of circEPB41L2 can also significantly inhibit the proliferation of HCC cells in vivo. Bioinformatic analysis and luciferase reporter assay revealed that circEPB41L2 interacts directly with miR-590-5p and the corresponding biological functions were also verified in miRNA rescue experiments.ConclusionOur results suggest that circEPB41L2 might function as a tumor suppressor during HCC progression by sponging miR-590-5p.

The aim of this study was to analyze the role of LINC01554 in the pathogenesis of hepatocellular carcinoma (HCC) and explore the potential mechanism through which LINC01554 affects the migration and proliferation of HCC cells. LINC01554 expression in HCC tissues and its link to the prognosis of patients were analyzed by The Cancer Genome Atlas (TCGA) database. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was carried out to examine LINC01554 levels in 60 cases of HCC clinical tissues and HCC cell lines. Then, LINC01554 overexpression model was constructed using lentivirus in HCC cell lines. HCC proliferation and invasive ability were evaluated through Cell Counting Kit (CCK-8) and transwell tests, respectively. Furthermore, the potential action mechanism of LINC01554 was explored using bioinformatics analysis and in vitro cell experiments. Analysis of the TCGA database revealed that LINC01554 was remarkably under-expressed in HCC tissues. Decreased expression of LINC01554 predicted a poor prognosis for patients. Besides, LINC01554 overexpression markedly blunted the proliferation and migratory capacities of HCC cells. LINC01554 competed with NGFR to bind to microRNA-3681-3p, thereby providing possible mechanisms by which LINC01554 could participate in the progression of HCC. This study shows for the first time that LINC01554 modulates NGFR expression by binding to microRNA-3681-3p, thereby participating in the progression of HCC.

To investigate the selective inhibitory effect of glycyrrhetinic acid on 4 hepatocellular carcinoma (HCC) cells with different proliferation rates and explore the underlying mechanisms. MTT method was used to detect the proliferation rates of 4 HCC cell lines, namely SMMC-7721, SK-HEP1, HEPG2 and HEP3B. Following treatment of the cells with glycyrrhetinic acid (5, 10, 20, 30, 40, and 60 µmol/L), the cell viability was analyzed using MTT assay and the expressions of total ERK protein, p-ERK protein and topoisomerase IIα were detected using Western blotting. Among the 4 cell lines, SMMC-7721 had the lowest and SK-HEP1 had the highest proliferation rate. Treatment with glycyrrhetinic acid for 48 h dose-dependently inhibited the proliferation of all the 4 cell lines in vitro and produced the strongest inhibitory effect in SMMC-7721 cells with the IC50 of 28.04 µmol/L. The proliferation rate of the cells was positively correlated with the expression levels of p-ERK and topoisomerase IIα, which were the lowest in SMMC-7721 cells and the highest in SK-HEP1 cells. Treatment with 50 µmol/L glycyrrhetinic acid significantly down-regulated the expressions of p-ERK and topoisomerase IIα in the 4 HCC cell lines (P<0.05), while 25 µmol/L glycyrrhetinic acid significantly reduced the expression of topoisomerase IIα and p-ERK in SMMC-7721, HEPG2 and HEP3B cells (P<0.05) but not in SK-HEP1 cells. Glycyrrhetinic acid can inhibit the proliferation of different HCC cells particularly in cells with a low proliferation rate. The inhibitory effect of glycyrrhetinic acid might be mediated by reducing the expressions of topoisomerase IIα and inhibiting the ERK pathway.

MicroRNA-504 functions as a tumor suppressor in hepatocellular carcinoma through inhibiting Frizzled-7-mediated-Wnt/β-catenin signaling