Promoted Hepatocellular Carcinoma Cell Proliferation Research Articles

BAP31 Promotes Tumor Cell Proliferation by Stabilizing SERPINE2 in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) patients are mostly diagnosed at an advanced stage, resulting in systemic therapy and poor prognosis. Therefore, the identification of a novel treatment target for HCC is important. B-cell receptor-associated protein 31 (BAP31) has been identified as a cancer/testis antigen; however, BAP31 function and mechanism of action in HCC remain unclear. In this study, BAP31 was demonstrated to be upregulated in HCC and correlated with the clinical stage. BAP31 overexpression promoted HCC cell proliferation and colony formation in vitro and tumor growth in vivo. RNA-sequence (RNA-seq) analysis demonstrated that serpin family E member 2 (SERPINE2) was downregulated in BAP31-knockdown HCC cells. Coimmunoprecipitation and immunofluorescence assays demonstrated that BAP31 directly binds to SERPINE2. The inhibition of SERPINE2 significantly decreased the BAP31-induced cell proliferation and colony formation of HCC cells and phosphorylation of Erk1/2 and p38. Moreover, multiplex immunohistochemistry staining of the HCC tissue microarray showed positive associations between the expression levels of BAP31, SERPINE2, its downstream gene LRP1, and a tumor proliferation marker, Ki-67. The administration of anti-BAP31 antibody significantly inhibited HCC cell xenograft tumor growth in vivo. Thus, these findings suggest that BAP31 promotes tumor cell proliferation by stabilizing SERPINE2 and can serve as a promising candidate therapeutic target for HCC.

A novel circular RNA circ-LRIG3 facilitates the malignant progression of hepatocellular carcinoma by modulating the EZH2/STAT3 signaling

BackgroundCircular RNA (circRNA) is emerging as an important player in human diseases, especially cancer. In our previous study, we identified a series of deregulated circRNAs in hepatocellular carcinoma (HCC) by performing circRNA microarray expression profile. Here, we aimed to explore the role of circ-LRIG3 (hsa_circ_0027345) in HCC.MethodsqRT-PCR and western blot were used to asses gene and protein expression, respectively. CCK-8, EdU and Transwell assays were used to detect cell proliferation, migration and invasion. GSEA software was applied to analyze the pathway related to circ-LRIG3. Co-IP, RIP and ChIP assays were used to identify the positive feedback axis of circ-LRIG3/EZH2/STAT3. Animal study was carried to test the role of circ-LRIG3 in vivo.ResultsCirc-LRIG3 was notably upregulated in HCC and promoted HCC cell proliferation, migration, invasion and reduced apoptosis. Circ-LRIG3 formed a ternary complex with EZH2 and STAT3, facilitating EZH2-induced STAT3 methylation and subsequent phosphorylation, resulting in the activation of STAT3 signaling. In turn, activated STAT3 could directly bind to circ-LRIG3 promoter to increase circ-LRIG3 transcription activity, thus forming a positive feedback loop. The animal models showed that exogenous expression of circ-LRIG3 enhanced tumorigenicity and metastasis in vivo, whereas these effects were blocked after treatment with C188–9, a specific STAT3 small-molecule inhibitor. Clinically, high circ-LRIG3 was closely linked with aggressive clinicopathological features and was identified as an independent risk prognostic factor of overall survival. Importantly, plasma circ-LRIG3 was found to be a highly sensitive and specific non-invasive diagnostic indicator for HCC.ConclusionsOur study reveals the carcinogenic role of circ-LRIG3 in HCC, which may provide a new therapeutic target for HCC patients.

Integrative analysis reveals novel driver genes and molecular subclasses of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a heterogeneous disease with various genetic and epigenetic abnormalities. Previous studies of HCC driver genes were primarily based on frequency of mutations and copy number alterations. Here, we performed an integrative analysis of genomic and epigenomic data from 377 HCC patients to identify driver genes that regulate gene expression in HCC. This integrative approach has significant advantages over single-platform analyses for identifying cancer drivers. Using this approach, HCC tissues were divided into four subgroups, based on expression of the transcription factor E2F and the mutation status of TP53. HCC tissues with E2F overexpression and TP53 mutation had the highest cell cycle activity, indicating a synergistic effect of E2F and TP53. We found that overexpression of the identified driver genes, stratifin (SFN) and SPP1, correlates with tumor grade and poor survival in HCC and promotes HCC cell proliferation. These findings indicate SFN and SPP1 function as oncogenes in HCC and highlight the important role of enhancers in the regulation of gene expression in HCC.

LncRNA Lnc712 Promotes Tumorigenesis in Hepatocellular Carcinoma by Targeting miR-142-3p/Bach-1 Axis.

BackgroundIt is known that Lnc712 plays an important role in the pathogenesis of breast cancer. However, whether it is involved in hepatocellular carcinoma (HCC) remains unknown. In this study, we aimed to investigate the role and underlying mechanism of Lnc712 in HCC.MethodsSixty-four HCC patients were enrolled and followed up for 5 years to analyze the prognostic value of Lnc712 for HCC. HCC cells were transfected with Lnc712 expression vector, Bach-1 expression vector (or siRNA) and miR-142-3p mimic (or inhibitor) to explore the interactions among Lnc712, miR-142-3p and Bach-1. Cell proliferation, migration, invasion and cell cycle were analyzed by CCK-8 assay, transwell assay, wound healing assay and flow cytometry assay, respectively.ResultsThe expression of Lnc712 was upregulated in HCC, and the upregulated Lnc712 expression was significantly related to poor overall survival in HCC patients. In HCC cells, Lnc712 interacted with miR-142-3p and upregulated Bach-1, a target of miR-142-3p. In addition, Lnc712 promoted HCC cell proliferation, migration, invasion and cell cycle, while its effects were abolished by miR-142-3p mimic. Moreover, miR-142-3p mimic enhanced HCC cell proliferation, migration, invasion and cell cycle, while its effects were abolished by Bach-1 overexpression. miR-142-3p inhibitor repressed cell proliferation, migration, invasion and cell cycle in HCC cells, while its effects were abolished by Bach-1 knockdown. Furthermore, Lnc712 knockdown remarkably inhibited HCC tumor growth in nude mice.ConclusionLnc712 may promote the development of HCC by targeting the miR-142-3p/Bach-1 axis.

The Mutational and Transcriptional Landscapes of Hepatocarcinogenesis in a Rat Model.

SummaryHepatocellular carcinoma (HCC) initiation is characterized by stepwise accumulation of molecular alterations, during which the early events are largely unknown. Here, we presented a comprehensive genomic and transcriptomic landscape at stages of hepatitis, cirrhosis, and HCC by using a diethylnitrosamine-induced rat HCC model. We observed the early occurrence of gene instability and aberrant cancer associated signaling pathways in liver hepatitis. We further characterized the progressive molecular changes during hepatocarcinogenesis, wherein the intense rivalry between tumor-suppressive and oncogenic strengths occurred in cirrhosis stage. Despite the significant pathological difference, mutation signatures and expression landscape are highly similar between hepatitis and cirrhosis stages. Furthermore, we identified PI3K-Akt signaling pathway as a key pathway in the process of hepatocarcinogenesis through integrative analysis, and PIK3CD is a potential biomarker indicating HCC recurrence. The dynamic immune response during hepatocarcinogenesis, such as continuous decline of monocytes, suggests an immunological intervention strategy beyond chemoprevention for liver cancer.

Increased dopamine and its receptor dopamine receptor D1 promote tumor growth in human hepatocellular carcinoma.

BackgroundDopamine and dopamine receptor D1 (DRD1), a member of the dopamine receptor family, have been indicated to play important roles in cancer progression, but dopamine secretion in hepatocellular carcinoma (HCC) and the effects of DRD1 on HCC remain unclear. This study was designed to explore the contribution of the dopaminergic system to HCC and determine the relationship between DRD1 and prognosis in HCC patients.MethodsThe dopamine metabolic system was monitored using enzyme‐linked immunosorbent assays (ELISAs). The expression of DRD1 was detected by microarray analysis, immunohistochemistry (IHC), and quantitative real‐time PCR (qRT‐PCR). Stable DRD1 knockout and overexpression cell lines were established for investigation. Transwell, colony formation, and Cell Counting Kit 8 (CCK8) assays were performed to assess the malignant behaviors of cancer cells. The cAMP/PI3K/AKT/ cAMP response element‐binding (CREB) signaling pathway was evaluated by Western blot. This pathway, which is agitated by DRD1 in striatal neurons, had been proven to participate in tumor progression. Xenograft HCC tumors were generated for in vivo experiments.ResultsDopamine secretion increased locally in HCC due to an imbalance in dopamine metabolism, including the upregulation of dopa decarboxylase (DDC) and the downregulation of monoamine oxidase A (MAOA). Dopamine promoted the proliferation and metastasis of HCC. DRD1 was highly expressed in HCC tissues and positive DRD1 expression was related to a poor prognosis in HCC patients. The upregulation of DRD1 agitated malignant activities, including proliferation and metastasis in HCC by regulating the cAMP/PI3K/AKT/CREB pathway, and the downregulation of DRD1 had opposing effects. The effects of dopamine on HCC was reversed by depleting DRD1. SCH23390, a selective DRD1 antagonist, inhibited the proliferation and metastasis of HCC cells both in vitro and in vivo.ConclusionDopamine secretion was locally increased in HCC and promoted HCC cell proliferation and metastasis. DRD1 was found to exert positive effects on HCC progression and play a vital role in the dopamine system, and could be a potential therapeutic target and prognostic biomarker for HCC.

RETRACTED: YTHDF1 Facilitates the Progression of Hepatocellular Carcinoma by Promoting FZD5 mRNA Translation in an m6A-Dependent Manner

Hepatocellular carcinoma (HCC), one of the most aggressive malignancies, ranks as the fourth leading cause of cancer-related deaths worldwide. Emerging evidence indicates that RNA N6-methyladenosine (m6A) plays a critical role in tumor progression. However, the biological function of YTHDF1 in HCC remains unclear. Here, we found that YTHDF1 expression was strikingly elevated in HCC tissues and cell lines and significantly associated with prognosis of HCC patients. Moreover, YTHDF1 expression was transcriptionally regulated by USF1 and c-MYC in HCC. Functional studies showed that YTHDF1 can promote HCC cell proliferation and metastasis both in vitro and in vivo. Multi-omics analysis revealed that YTHDF1 can accelerate the translational output of FZD5 mRNA in an m6A-dependent manner and function as an oncogene through the WNT/β-catenin pathway. Taken together, our study revealed an essential role of YTHDF1 in the progression of HCC cells, which indicated that targeting YTHDF1 may be a potential therapeutic strategy in HCC.

Ezrin promotes hepatocellular carcinoma progression by modulating glycolytic reprogramming.

Ezrin, one of the ezrin‐radixin‐moesin (ERM) proteins, is involved in the formation of cell membrane processes and has been implicated in the promotion of cancer proliferation and metastasis. However, the possible role of ezrin in hepatocellular carcinoma (HCC) metastasis and glycolysis reprogramming has remained unclear. In this study, we found that ezrin was upregulated in HCC tissues, and its overexpression was linked with HCC patients’ aggressive tumor characteristics and poor prognosis. Functional experiments further revealed that ezrin overexpression promoted HCC cell proliferation, epithelial‐to‐mesenchymal transition (EMT) progression and angiogenesis. In addition, by measuring glucose consumption, lactate production, ATP levels and the expression of glucose metabolism‐related markers in HCC cells, we investigated whether ezrin regulated glucose metabolism. Moreover, 2‐deoxy‐D‐glucose (2‐DG) affected ezrin‐mediated proliferation, migration and EMT of HCC cells, which suggested that ezrin may, at least in part, promote HCC progression by regulating glycolysis reprogramming. Based on our results, we proposed that ezrin was involved in HCC progression and may be a valid prognostic marker.

Circular RNA Sequencing Identifies CircASAP1 as a Key Regulator in Hepatocellular Carcinoma Metastasis.

There is growing evidence that single-stranded, circular RNA (circRNA) plays a key role in the development of certain cancers, including hepatocellular carcinoma (HCC). It is less clear, however, what role circRNA plays in HCC metastasis. In this study, through circRNA sequencing, we identified a circRNA: circASAP1 (a circRNA derived from exons 2 and 3 of the ASAP1 gene, hsa_circ_0085616), which is associated with pulmonary metastasis after curative resection in patients with HCC. CircASAP1 was overexpressed in HCC cell lines with high metastatic potential and in metastatic HCCs. In vitro, circASAP1 promoted cell proliferation, colony formation, migration, and invasion, and in vivo, it enhanced tumor growth and pulmonary metastasis. Mechanism studies showed that circASAP1 acts as a competing endogenous RNA for microRNA 326 (miR-326) and microRNA 532-5p (miR-532-5p), both of which are tumor suppressors in HCC. We found that mitogen-activated protein kinase (MAPK) 1 and colony stimulating factor (CSF)-1 were direct common targets for microRNA 326 (miR-326) and microRNA 532-5p (miR-532-5p), which were regulated by circASAP1. CircASAP1 promotes HCC cell proliferation and invasion by regulating miR-326/miR-532-5p-MAPK1 signaling and, furthermore, mediates tumor-associated macrophage infiltration by regulating the miR-326/miR-532-5p-CSF-1 pathway. Clinical HCC samples exhibited a positive correlation between circASAP1 expression and levels of CSF-1, MAPK1, and CD68+ tumor-associated macrophages, all of which were predictive of patient outcomes. We identified circASAP1 as a key regulator of HCC metastasis that acts on miR-326/miR-532-5p-MAPK1/CSF-1 signaling and serves as a prognostic predictor in patients with HCC.

MAPRE1 promotes cell cycle progression of hepatocellular carcinoma cells by interacting with CDK2.

Targeting cyclin-dependent kinases (CDKs) is a promising method of therapy for cancer. Unfortunately, the efficacy of CDK inhibitors in hepatocellular carcinoma (HCC) is limited, due in part to incomplete understanding of cell cycle progression and a lack of specific biomarkers to adequately identify which patients may be responsive to CDK inhibitors. In the present study, we report that microtubule-associated protein RP/EB family member 1 (MAPRE1), a gene involved in cell cycle and microtubule regulation, is significantly increased in HCC tissue, promotes HCC cell proliferation, enhances in vitro tumorigenesis, and associates with poor prognosis of HCC. We demonstrate that MAPRE1 binds with CDK2, resulting in the hyperphosphorylation of the CDK2 Thr161 residue in HCC cells. Our findings reveal that targeting MAPRE1 might be an effective therapeutic strategy in HCC, and suggest that MAPRE1 expression might provide a promising biomarker to stratify patients with HCC who may benefit from treatment with CDK inhibitors.

MicroRNA‑875‑5p inhibits tumor growth and metastasis of hepatocellular carcinoma by targeting eukaryotic translation initiation factor 3 subunit a.

Accumulating evidence has demonstrated that aberrant microRNA (miRNA) expression is involved in hepatocellular carcinoma (HCC) progression. Previous findings suggested that miRNA (miR)-875-5p participates in the development of various types of cancer. However, the expression and function of miR-875-5p in HCC remains largely unclear. The analysis of clinical samples in the present study demonstrated that miR-875-5p expression was downregulated in HCC tissues compared to adjacent non-tumor tissues, which was associated with a large tumor size, venous infiltration, advanced tumor-node-metastasis stage and unfavorable overall survival. In vitro experiments revealed that ectopic expression of miR-875-5p suppressed, whereas inhibition of miR-875-5p promoted HCC cell proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT) progression. Overexpression of miR-875-5p restrained HCC tumor growth and metastasis in vivo. Mechanistically, eukaryotic translation initiation factor 3 subunit a (eIF3a) was identified as the downstream target of miR-875-5p in HCC. Further experiments demonstrated that the expression of eIF3a was upregulated and negatively correlated with that of miR-875-5p in HCC tissues. In addition, miR-875-5p negatively regulated the luciferase activity of wild-type, but not mutant 3′-untranslated region (3′UTR) of eIF3a mRNA. miR-875-5p suppressed eIF3a expression at the mRNA and protein level in HCC cells. Additionally, eIF3a exerted an oncogenic role, and knockdown of eIF3a inhibited the proliferation, motility and EMT of HCC cells. In addition, eIF3a overexpression abolished the inhibitory effects of miR-875-5p on the proliferation, motility and EMT in HCC cells. In conclusion, miR-875-5p, which was downregulated in HCC, may inhibit tumor growth and metastasis by eIF3a downregulation via targeting its 3′UTR and may be a promising prognostic and therapeutic strategy in HCC.

MiR-135b promotes HCC tumorigenesis through a positive-feedback loop

Hippo pathway plays critical roles in cell proliferation and apoptosis and its dysregulation leads to various types of cancers, including hepatocellular carcinoma (HCC). However, the mechanism maintaining Hippo pathway homeostasis still remains unclear. In this study, we discovered that the expression of miR-135b is apparently upregulated in HCC tissues and HCC cell lines. The level of miR-135b was positively correlated with HCC stages and negatively correlated with the survival of HCC patients, suggesting an oncogenic role of miR-135b in HCC progression. Similarly, miR-135b mimic promoted HCC cell proliferation and migration, whereas its inhibitor played an opposite role. Mechanistically, we identified a seed sequence of miR-135b in the MST1 3′-UTR region. MiR-135b inhibited the Hippo pathway by silencing MST1 expression. Additionally, we revealed that miR-135b was a transcriptional target of the Hippo pathway. Based on these data, we propose that a positive-feedback axis of MST1-YAP-miR-135b exists for HCC aggravation. Our study not only deepens the insight into the Hippo pathway homeostasis, but also suggests miR-135b as a potential prognosis biomarker and therapeutic target for HCC.

KIF2C: a novel link between Wnt/\u03b2-catenin and mTORC1 signaling in the pathogenesis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is the fourth-leading cause of cancer-related deaths worldwide. HCC is refractory to many standard cancer treatments and the prognosis is often poor, highlighting a pressing need to identify biomarkers of aggressiveness and potential targets for future treatments. Kinesin family member 2C (KIF2C) is reported to be highly expressed in several human tumors. Nevertheless, the molecular mechanisms underlying the role of KIF2C in tumor development and progression have not been investigated. In this study, we found that KIF2C expression was significantly upregulated in HCC, and that KIF2C up-regulation was associated with a poor prognosis. Utilizing both gain and loss of function assays, we showed that KIF2C promoted HCC cell proliferation, migration, invasion, and metastasis both in vitro and in vivo. Mechanistically, we identified TBC1D7 as a binding partner of KIF2C, and this interaction disrupts the formation of the TSC complex, resulting in the enhancement of mammalian target of rapamycin complex1 (mTORC1) signal transduction. Additionally, we found that KIF2C is a direct target of the Wnt/β-catenin pathway, and acts as a key factor in mediating the crosstalk between Wnt/β-catenin and mTORC1 signaling. Thus, the results of our study establish a link between Wnt/β-catenin and mTORC1 signaling, which highlights the potential of KIF2C as a therapeutic target for the treatment of HCC.

Neurotrophin 3 hinders the growth and metastasis of hepatocellular carcinoma cells*

Abstract Objective Neurotrophin 3 (NTF3) is involved in numerous biological processes; however, its role in hepatocellular carcinoma (HCC) is not well studied. This study investigated NTF3 function in HCC progression and revealed its underlying molecular mechanisms. Methods The prognostic relevance of NTF3 was determined through a bioinformatical analysis of publicly available TCGA data. Immunohistochemistry of HCC biopsies was performed to explore the expression of NTF3. Cell growth and proliferation were analyzed using a Cell Counting Kit-8 (CCK-8) assay. Cell invasion and migration were analyzed using Boyden Transwell and wound healing assays. Protein expression and mRNA levels were evaluated through immunoblotting and quantitative polymerase chain reaction (qPCR). Cell apoptosis was evaluated with flow cytometry. Results NTF3 expression was significantly lower in HCC tissues than in adjacent non-tumor tissues. Low NTF3 expression was significantly associated with decreased patient survival and specific clinicopathological features. NTF3 overexpression reduced the proliferation, migration, and invasion abilities of HCC cell lines. Conclusion Decreased expression of NTF3 is associated with poor prognosis in HCC patients, likely due to its action in promoting HCC cell proliferation, migration, and invasion. Our findings provide a novel understanding into the pathogenesis of HCC and the role of NTF3 in tumor progression, suggesting that targeting NTF3 has potential therapeutic and diagnostic value for HCC.

KDM6A suppresses hepatocellular carcinoma cell proliferation by negatively regulating the TGF-β/SMAD signaling pathway.

Lysine demethylase 6A (KDM6A) is a Jumonji-C domain-containing histone demethylase that specifically catalyzes the removal of histone H3 lysine-27 trimethylation. KDM6A is a member of the KDM6 family, the biological role of which has been reported in various types of cancer, including bladder and lung cancer, as well as pancreatic ductal adenocarcinoma. However, the role of KDM6A in hepatocellular carcinoma (HCC) is not completely understood. Therefore, the present study aimed to determine the biological function of KDM6A in HCC progression. The expression profile of KDM6A was examined in HCC surgical specimens using reverse transcription-quantitative PCR. In addition, the role of KDM6A in the proliferation capacities of HCC cell lines was examined in vitro and in vivo using crystal violet and MTT assays. The underlying mechanism by which KDM6A exerts its function was explored by western blotting. The present study indicated that KDM6A was significantly downregulated in HCC tissues compared with normal control tissues. The role of KDM6A in HCC cell proliferation was also determined. KDM6A overexpression significantly inhibited HCC cell proliferation, whereas KDM6A knockdown significantly promoted HCC cell proliferation compared with the corresponding control groups. Consistently, KDM6A overexpression suppressed HCC cell tumorigenesis in vivo. The western blotting results indicated that KDM6A overexpression decreased the phosphorylation levels of smad2, whereas KDM6A knockdown increased the phosphorylation levels of smad2 compared with the corresponding control groups. Therefore, the present study suggested that KDM6A may inhibit HCC cell proliferation by negatively regulating the TGF-β/SMAD signaling pathway, suggesting that KDM6A may serve as a potential target for the diagnosis and treatment of HCC.

Long noncoding RNA ZFPM2-AS1 regulates ITGB1 by miR-1226-3p to promote cell proliferation and invasion in hepatocellular carcinoma.

Long noncoding RNA (lncRNA) is emerging as a vital regulator in various tumors. However, the biological function of ZFPM2-antisense RNA 1 (ZFPM2-AS1) in hepatocellular carcinoma (HCC) remains unclear. The present study aims to explore the function and mechanism of ZFPM2-AS1 in hepatocellular carcinoma progression. The ZFPM2-AS1 expression in HCC cells and tissues was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Effects of ZFPM2-AS1 on tumor cell proliferation and invasion were detected by CCK8 assay or EdU assay or matrigel migration assay and Western blot. The Luciferase reporter assay, RNA pulldown assay, qRT-PCR, and Western blot were performed to explore and confirm the interaction between ZFPM2-AS1 and miR-1226-3p and integrin β1 (ITGB1). ZFPM2-AS1 was overexpressed in HCC tissues and cell lines. High levels of ZFPM2-AS1 were correlated with advanced TNM stage, distant metastasis and a poorer overall survival rate. ZFPM2-AS1 knockdown inhibited cell proliferation and invasion. ZFPM2-AS1 could directly bind to and negatively regulate miR-1226-3p expression. Moreover, ITGB1 was identified as a target gene of miR-1226-3p. ITGB1 was found to be directly negatively regulated by miR-1226-3p and indirectly upregulated by ZFPM2-AS1. Rescue assays demonstrated that ZFPM2-AS1 promotes HCC cell proliferation and invasion through modulating miR-1226/ITGB1 axis. ZFPM2-AS1 promotes cell proliferation and migration by regulating miR-1226-3p/ITGB1 axis in HCC.

LINC01419 promotes cell proliferation and metastasis in hepatocellular carcinoma by enhancing NDRG1 promoter activity.

Emerging evidence indicates that dysfunction of long non-coding RNAs (lncRNAs) plays an essential role in the initiation and progression of hepatocellular carcinoma (HCC). In this study we investigated the potential roles and molecular mechanisms involving LINC01419 in HCC. The expression of LINC01419 in 40 pairs of HCC/normal tissues and 6 HCC cell lines was detected by qRT-PCR. MTS, EdU, colony formation, scratch wound-healing and transwell assays were performed to assess the role of LINC01419 in HCC cell (SMMC7721 and SK-Hep1) proliferation, migration and invasion in vitro. Artificial modulation of LINC01419 (up- and downregulation) was performed to explore the role of LINC01419 in tumor growth and metastasis in vivo. Interaction of LINC01419 with NDRG1 was assessed using qRT-PCR, RNA sequencing, Western blotting and immunohistochemistry. Physical interaction of LINC01419 with the NDRG1 promoter was assessed using a dual-luciferase reporter assay. We observed LINC01419 overexpression in primary HCC tissues and HCC cell lines and that this overexpression positively correlated with large tumor size, increased vascular invasion and advanced TNM stage in 40 HCC patients. Exogenous LINC01419 expression significantly promoted HCC cell proliferation, migration and invasion in vitro, as well as tumorigenesis and metastasis in vivo. Conversely, we found that LINC01419 expression knockdown elicited opposite effects. Mechanistic investigations revealed that LINC01419 exerted its biological effects by regulating NDRG1. A dual-luciferase reporter assay revealed that LINC01419 interacts with a specific region within the NDRG1 promoter, resulting in its activation. From our data we conclude that LINC01419 acts clinically, functionally and mechanistically oncogenic in HCC. LINC01419 may, therefore, serve as a promising prognostic indicator and therapeutic target for HCC.

ZNF143-Mediated H3K9 Trimethylation Upregulates CDC6 by Activating MDIG in Hepatocellular Carcinoma.

Zinc finger protein 143 (ZNF143) belongs to the zinc finger protein family and possesses transcription factor activity by binding sequence-specific DNA. The exact biological role of ZNF143 in hepatocellular carcinoma (HCC) has not been investigated. Here we report that ZNF143 is overexpressed in HCC tissues and its overexpression correlates with poor prognosis. Gain- and loss-of-function experiments showed that ZNF143 promoted HCC cell proliferation, colony formation, and tumor growth in vitro and in vivo. ZNF143 accelerated HCC cell-cycle progression by activating cell division cycle 6 (CDC6). Mechanistically, ZNF143 promoted expression of CDC6 by directly activating transcription of histone demethylase mineral dust-induced gene (MDIG), which in turn reduced H3K9me3 enrichment in the CDC6 promoter region. Consistently, ZNF143 expression correlated significantly with MDIG and CDC6 expression in HCC. Collectively, we propose a model for a ZNF143-MDIG-CDC6 oncoprotein axis that provides novel insight into ZNF143, which may serve as a therapeutic target in HCC. SIGNIFICANCE: These findings describe the mechanism by which ZNF143 promotes HCC proliferation and provide important clues for exploring new targets and strategies for clinical treatment of human liver cancer.

Long noncoding RNA MALAT1 inhibits the apoptosis and autophagy of hepatocellular carcinoma cell by targeting the microRNA-146a/PI3K/Akt/mTOR axis

BackgroundIncreased long noncoding RNA (lncRNA) expression is characteristic to hepatocellular carcinoma (HCC) and several other neoplasms. The present study aimed to identify the mechanism underlying modulation of HCC development by the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1).MethodsQuantitative real-time polymerase chain reaction was used to determine MALAT1 and microRNA (miR)-146a expression in HCC tissues and cell lines. Western blotting was performed to measure PI3K, Akt, and mTOR levels. Dual-luciferase reporter assay was used to validate the direct targeting and negative regulatory interaction between miR-146a and MALAT1. Cell viability, proliferation, and apoptosis were analyzed using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay, colony formation assay, and flow cytometry, respectively; autophagy was detected based on LC3B expression.ResultsMALAT1 expression was higher in HCC tissues than in normal tissues. MALAT1 upregulation promoted HCC cell proliferation, whereas MALAT1 downregulation promoted HCC apoptosis and autophagy. Moreover, effects of MALAT1 downregulation on HCC cells were abolished by miR-146a inhibition. miR-146a directly targeted the 3′-untranslated region of PI3K, and PI3K protein level was clearly decreased upon miR-146a mimic transfection.ConclusionsMALAT1 may modulate HCC cell proliferation, apoptosis, and autophagy via sponging miR-146a, which regulates HCC progression.

NT5DC2 promotes tumor cell proliferation by stabilizing EGFR in hepatocellular carcinoma

Most hepatocellular carcinoma (HCC) patients are diagnosed at an advanced stage; however, the effect of systemic therapy on advanced HCC remains undetermined. Therefore, new treatment targets must be identified. We analyzed Gene Expression Omnibus datasets from two HCC patient cohorts and found that NT5DC2 was associated with vascular invasion and poor survival. In two hepatoma cell lines, NT5DC2 overexpression promoted HCC cell proliferation and clone formation in vitro and promoted tumor growth in vivo. Coimmunoprecipitation assays and liquid chromatography with tandem mass spectrometry analysis revealed that NT5DC2 bound directly to epidermal growth factor receptor (EGFR). NT5DC2 upregulated EGFR expression by downregulating EGFR ubiquitination and preventing its degradation via the ubiquitin-proteasome pathway but did not upregulate its transcription. EGFR upregulation activated downstream signal transduction, which played a critical role in the protumor effects of NT5DC2. Erlotinib, a small-molecule inhibitor of EGFR, blocked the effect of NT5DC2 in promoting HCC cell proliferation. In a cohort of 79 patients who underwent curative resection for HCC, NT5DC2 expression in the tumors was associated with larger tumors and microvascular invasion. NT5DC2 expression was also independently associated with recurrence-free survival. The present study demonstrated for the first time that NT5DC2 promotes tumor cell proliferation in HCC and may serve as a potential molecular target for treating HCC. EGFR blockage could be used to treat selected patients with NT5DC2 upregulation.