scholarly journals LncRNA MYLK-AS1 facilitates tumor progression and angiogenesis by targeting miR-424-5p/E2F7 axis and activating VEGFR-2 signaling pathway in hepatocellular carcinoma

2020 ◽  
Author(s):  
Fei Teng ◽  
Ju-Xiang Zhang ◽  
Qi-Meng Chang ◽  
Xu-Bo Wu ◽  
Wei-Guo Tang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Tumor Progression ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Rna Binding ◽  
Normal Liver ◽  
Bioinformatic Analysis ◽  
Luciferase Reporter ◽  
E2f Transcription Factor

Abstract Background: Long non-coding RNAs (lncRNAs) are crucial in the invasion, angiogenesis, progression, and metastasis of hepatocellular carcinoma (HCC). The lncRNA MYLK-AS1 promotes the growth and invasion of HCC through the EGFR/HER2-ERK1/2 signaling pathway. However, the clinical significance of MYLK-AS1 in HCC still needs to be further determined.Methods: Bioinformatic analysis was performed to determine the potential relationship among MYLK-AS1, miRNAs and mRNAs. A total of 156 samples of normal liver and paired HCC tissues from HCC patients were used to evaluate MYLK-AS1 expression by qRT-PCR. Human HCC cell lines were used to evaluate the colony formation, cell proliferation, migration, invasion, cell cycle and apoptosis after transfection of lentiviral short-hairpin RNAs (shRNAs) targeting MYLK-AS1 or MYLK-AS1 vectors. The competitive endogenous RNA (ceRNA) mechanism was clarified using fluorescence in situ hybridization (FISH), Western blotting, qPCR, RNA binding protein immunoprecipitation (RIP), and dual luciferase reporter analysis.Results: MYLK-AS1 up-regulation was detected in the HCC tumor tissues and cell lines associated with the enhancement of the angiogenesis and tumor progression. The down-regulation of MYLK-AS1 reversed the effects on angiogenesis, proliferation, invasion and metastasis in the HCC cells and in vivo. MYLK-AS1 acted as ceRNA, capable of regulating the angiogenesis in HCC, while the microRNA miR-424-5p was the direct target of MYLK-AS1. Promoting the angiogenesis and the tumor proliferation, the complex MYLK-AS1/miR-424-5p activated the VEGFR2 signaling through E2F7, whereas the specific targeting of E2F transcription factor 7 (E2F7) by miR-424-5p, was indicated by the mechanism studies.Conclusions: MYLK-AS1 and E2F7 are closely related to some malignant clinicopathological features and prognosis of HCC, thus the MYLK-AS1/ miR-424-5p/E2F7 signaling pathway might represent a promising treatment strategy to combat HCC.

scholarly journals LncRNA MYLK-AS1 facilitates tumor progression and angiogenesis by targeting miR-424-5p/E2F7 axis and activating VEGFR-2 signaling pathway in hepatocellular carcinoma

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Fei Teng ◽  
Ju-Xiang Zhang ◽  
Qi-Meng Chang ◽  
Xu-Bo Wu ◽  
Wei-Guo Tang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Tumor Progression ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Rna Binding ◽  
Normal Liver ◽  
Bioinformatic Analysis ◽  
Luciferase Reporter ◽  
E2f Transcription Factor

Abstract Background Long non-coding RNAs (lncRNAs) are crucial in the invasion, angiogenesis, progression, and metastasis of hepatocellular carcinoma (HCC). The lncRNA MYLK-AS1 promotes the growth and invasion of HCC through the EGFR/HER2-ERK1/2 signaling pathway. However, the clinical significance of MYLK-AS1 in HCC still needs to be further determined. Methods Bioinformatic analysis was performed to determine the potential relationship among MYLK-AS1, miRNAs and mRNAs. A total of 156 samples of normal liver and paired HCC tissues from HCC patients were used to evaluate MYLK-AS1 expression by qRT-PCR. Human HCC cell lines were used to evaluate the colony formation, cell proliferation, migration, invasion, cell cycle and apoptosis after transfection of lentiviral short-hairpin RNAs (shRNAs) targeting MYLK-AS1 or MYLK-AS1 vectors. The competitive endogenous RNA (ceRNA) mechanism was clarified using fluorescence in situ hybridization (FISH), Western blotting, qPCR, RNA binding protein immunoprecipitation (RIP), and dual luciferase reporter analysis. Results MYLK-AS1 up-regulation was detected in the HCC tumor tissues and cell lines associated with the enhancement of the angiogenesis and tumor progression. The down-regulation of MYLK-AS1 reversed the effects on angiogenesis, proliferation, invasion and metastasis in the HCC cells and in vivo. MYLK-AS1 acted as ceRNA, capable of regulating the angiogenesis in HCC, while the microRNA miR-424-5p was the direct target of MYLK-AS1. Promoting the angiogenesis and the tumor proliferation, the complex MYLK-AS1/miR-424-5p activated the VEGFR-2 signaling through E2F7, whereas the specific targeting of E2F transcription factor 7 (E2F7) by miR-424-5p, was indicated by the mechanism studies. Conclusions MYLK-AS1 and E2F7 are closely related to some malignant clinicopathological features and prognosis of HCC, thus the MYLK-AS1/ miR-424-5p/E2F7 signaling pathway might represent a promising treatment strategy to combat HCC.

scholarly journals Long non-coding RNA CCDC183-AS1 acts AS a miR-589-5p sponge to promote the progression of hepatocellular carcinoma through regulating SKP1 expression

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
He Zhu ◽  
Hongwei Zhang ◽  
Youliang Pei ◽  
Zhibin Liao ◽  
Furong Liu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Cell Lines ◽  
Human Cancer ◽  
Quantitative Polymerase Chain Reaction ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
High Morbidity ◽  
Regulatory Relationship

Abstract Background Hepatocellular carcinoma (HCC) is a common type of malignant human cancer with high morbidity and poor prognosis, causing numerous deaths per year worldwide. Growing evidence has been demonstrated that long non-coding RNAs (lncRNAs) are closely associated with hepatocarcinogenesis and metastasis. However, the roles, functions, and working mechanisms of most lncRNAs in HCC remain poorly defined. Methods Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression level of CCDC183-AS1 in HCC tissues and cell lines. Cell proliferation, migration and invasion ability were evaluated by CCK-8 and transwell assay, respectively. Animal experiments were used to explore the role of CCDC183-AS1 and miR-589-5p in vivo. Bioinformatic analysis, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to confirm the regulatory relationship between CCDC183-AS1, miR-589-5p and SKP1. Results Significantly upregulated expression of CCDC183-AS1 was observed in both HCC tissues and cell lines. HCC patients with higher expression of CCDC183-AS1 had a poorer overall survival rate. Functionally, overexpression of CCDC183-AS1 markedly promoted HCC cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo, whereas the downregulation of CCDC183-AS1 exerted opposite effects. MiR-589-5p inhibitor counteracted the proliferation, migration and invasion inhibitory effects induced by CCDC183-AS1 silencing. Mechanistically, CCDC183-AS1 acted as a ceRNA through sponging miR-589-5p to offset its inhibitory effect on the target gene SKP1, then promoted the tumorigenesis of HCC. Conclusions CCDC183-AS1 functions as an oncogene to promote HCC progression through the CCDC183-AS1/miR-589-5p/SKP1 axis. Our study provided a novel potential therapeutic target for HCC patients.

scholarly journals Long non-coding RNA LINC00641 promotes the growth and invasiveness of hepatocellular carcinoma by antagonizing miR-501-3p

2021 ◽  
Author(s):  
Haitao Xie ◽  
Hui Zhou ◽  
Yan Jiang ◽  
Wenqian Xu ◽  
Leping Zeng ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Normal Liver ◽  
In Vivo Studies ◽  
Luciferase Reporter ◽  
Normal Tissues ◽  
Non Coding Rna ◽  
Long Non Coding Rna ◽  
Proliferation And Invasion ◽  
Hcc Cells

IntroductionLong non-coding RNA LINC00641 has been reported to regulate tumor progression in several cancers. However, the expression and function of LINC00641 in hepatocellular carcinoma (HCC) is still unclear.Material and methodsIn this study, we measured the expression of LINC00641 in 79 pairs of HCC and adjacent normal liver tissues. The clinical significance of LINC00641 in HCC was explored. We also investigated the function of LINC00641 in HCC proliferation and invasion.ResultsWe observed that LINC00641 expression was significantly increased in HCC relative to normal tissues (P < 0.0001). High expression of LINC00641 was significantly associated with vascular invasion, advanced TNM stage, and reduced overall survival in HCC patients. Knockdown of LINC00641 inhibited the proliferation, colony formation, and invasion of HCC cells. In contrast, overexpression of LINC00641 promoted HCC cell growth and invasiveness. In vivo studies confirmed that knockdown of LINC00641 restrained tumorigenesis of HCC cells. Mechanistic studies revealed that LINC00641 inhibited the expression of miR-501-3p, which has been previously reported to act as a tumor suppressor in HCC. Furthermore, luciferase reporter assays validated that LINC00641 harbored a target site for miR-501-3p. Rescue experiments demonstrated that LINC00641-induced proliferation and invasion of HCC cells was reversed by co-expression of miR-501-3p.ConclusionsTaken together, LINC00641 contributes to aggressive phenotype of HCC cells by sponging miR-501-3p and represents a promising therapeutic target for this disease.

scholarly journals Tumor-Suppressive Role of microRNA-202-3p in Hepatocellular Carcinoma Through the KDM3A/HOXA1/MEIS3 Pathway

2021 ◽  
Vol 8 ◽  
Author(s):  
Yijie Zhang ◽  
Qi Pan ◽  
Zigong Shao
Keyword(s):  
Hepatocellular Carcinoma ◽  
Normal Liver ◽  
Global Scale ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Luciferase Reporter Gene ◽  
Gene Assay ◽  
Patient Prognosis ◽  
Hcc Cells

Hepatocellular carcinoma (HCC) represents a malignant tumor predominantly arising in the setting of cirrhosis and is the third most common cause of cancer-associated death on a global scale. The heterogeneous nature of HCC and limited well-recognized biomarkers may contribute to poor patient prognosis and treatment failure. In this study, we identified expression pattern of microRNA-202-3p (miR-202-3p) in HCC and characterized its functional role as well as related mechanisms. First, we collected 50 HCC tissues and 38 normal liver tissues, and after bioinformatics prediction, the expression of miR-202-3p and KDM3A was determined in the tissues. We found lowly expressed miR-202-3p and overexpressed KDM3A in HCC tissues. Then, dual-luciferase reporter gene assay was employed to test the presence of miR-202-3p binding sites in the 3’UTR of KDM3A and chromatin immunoprecipitation (ChIP) assay to homeobox A1 (HOXA1) interaction with KDM3A and MEIS3. It has been confirmed that miR-202-3p negatively regulated KDM3A responsible for increasing the expression of HOXA1 by eliminating the histone H3 lysine 9 (H3K9)me2 in HCC cells. HOXA1 could evidently increase H3K4me1 and H3K27ac enrichment in the MEIS3 enhancer region and enhance the expression of MEIS3. Functional assays were also performed with the results showing that upregulated miR-202-3p or downregulated KDM3A retarded HCC cell viability, migration, and invasion. In addition, HepG2 cells were xenografted into nude mice, and we demonstrated that upregulated miR-202-3p reduced the growth of human HCC cells in vivo. Taken together, the present study elicits a novel miR-202-3p/KDM3A/HOXA1/MEIS3 pathway in HCC, potentiating an exquisite therapeutic target for HCC.

scholarly journals MiR-196b-5p regulates the proliferation of drug-resistant hepatocellular carcinoma cell lines by activating NFκB/ABCB1 signaling pathway

2020 ◽  
Vol 19 (1) ◽  
pp. 39-44
Author(s):  
Bangming Pu ◽  
Yong Cao ◽  
Yan Li ◽  
Li Tang ◽  
Jiyi Xia ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Hepg2 Cells ◽  
Luciferase Reporter Assay ◽  
Luciferase Reporter ◽  
Drug Resistant ◽  
Reporter Assay

Purpose: To explore the molecular function of miR-196b-5p in hepatocellular carcinoma (HCC).Methods: MiR-196b-5p expression levels in HCC tissue samples were assessed by qRT-PCR. MiR-196b-5p was knocked-down or over-expressed in HepG2 cells by transfecting the cells with plasmids expressing either a miR-196b-5p inhibitor or mimic, respectively, while cell proliferation was  assessed by MTT assay. The interaction of miR-196b-5p with target molecules was confirmed using luciferase reporter assay. Cell cycle was investigated by flow cytometry, while NFκBIA expression was assessed by western blotting.Results: MiR-196b-5p was over-expressed in HCC, and miR-196b-5p expression levels in patients with HCC were related to tumor grade. MiR-196b-5p over-expression promoted cell proliferation and colony formation and suppressed cell cycle arrest and apoptosis. The results of luciferase reporter assay showed that miR-196b-5p reduced NFκBIA expression in HepG2 cells by binding to a response element in the 3′ UTR of NFκBIA. Further investigation showed that NFκBIA interacts with NFκB1 and reduces the concentration of NFκB1 in HepG2 cells. The promoter of ATP-binding cassette sub-family B member 1 (ABCB1) was also targeted and bound by NFκB1, which altered the expression of ABCB1 in HepG2 cells.Conclusion: MiR-196b-5p regulates cell proliferation in drug-resistant HCC cell lines via activation of the NFκB/ABCB1 signaling pathway. Keywords: Hepatocellular carcinoma, miR-196b-5p, NFκBIA, NFκB1, ABCB1

scholarly journals CircMTO1 suppresses hepatocellular carcinoma progression via the miR-541-5p/ZIC1 axis by regulating Wnt/β-catenin signaling pathway and epithelial-to-mesenchymal transition

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Dandan Li ◽  
Jiawei Zhang ◽  
Jing Yang ◽  
Jie Wang ◽  
Runling Zhang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Tumor Growth ◽  
Epithelial To Mesenchymal Transition ◽  
Bioinformatic Analysis ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Signal Pathways ◽  
Mesenchymal Transition

AbstractCircRNA mitochondrial tRNA translation optimization 1 (circMTO1) functions as a tumor suppressor usually and is related to the progression of many tumors, including hepatocellular carcinoma (HCC). CircMTO1 is downregulated in HCC as compared to adjacent nontumor tissue, which may suppress the HCC progression by certain signal pathways. However, the underlying signal pathway remains largely unknown. The interactions between circMTO1 and miR-541-5p were predicted through bioinformatics analysis and verified using pull-down and dual-luciferase reporter assays. CCK-8, transwell, and apoptosis assays were performed to determine the effect of miR-541-5p on HCC progression. Using bioinformatic analysis, dual-luciferase reporter assay, RT-qPCR, and western blot, ZIC1 was found to be the downstream target gene of miR-541-5p. The regulatory mechanisms of circMTO1, miR-541-5p, and ZIC1 were investigated using in vitro and in vivo rescue experiments. The results depicted that silencing circMTO1 or upregulating miR-541-5p expression facilitated HCC cell proliferation, migration, and invasion and inhibited apoptosis. CircMTO1 silencing upregulated the expression of downstream ZIC1 regulators of the Wnt/β-catenin pathway markers, β-catenin, cyclin D1, c-myc, and the mesenchymal markers N-cadherin, Vimentin, and MMP2, while the epithelial marker E-cadherin was downregulated. MiR-541-5p knockdown had the opposite effect and reversed the effect of circMTO1 silencing on the regulation of downstream ZIC1 regulators. Intratumoral injection of miR-541-5p inhibitor suppressed tumor growth and reversed the effect of circMTO1 silencing on the promotion of tumor growth in HCC. These findings indicated that circMTO1 suppressed HCC progression via the circMTO1/ miR-541-5p/ZIC1 axis by regulating Wnt/β-catenin signaling and epithelial-to-mesenchymal transition, making it a novel therapeutic target.

scholarly journals FUS-induced circRHOBTB3 facilitates cell proliferation via miR-600/NACC1 mediated autophagy response in pancreatic ductal adenocarcinoma

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Taoyue Yang ◽  
Peng Shen ◽  
Qun Chen ◽  
Pengfei Wu ◽  
Hao Yuan ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Cell Lines ◽  
Rna Binding ◽  
Ductal Adenocarcinoma ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Pdac Cell

Abstract Background Circular RNAs (circRNAs) are becoming a unique member of non-coding RNAs (ncRNAs) with emerging evidence of their regulatory roles in various cancers. However, with regards to pancreatic ductal adenocarcinoma (PDAC), circRNAs biological functions remain largely unknown and worth investigation for potential therapeutic innovation. Methods In our previous study, next-generation sequencing was used to identify differentially expressed circRNAs in 3 pairs of PDAC and adjacent normal tissues. Further validation of circRHOBTB3 expression in PDAC tissues and cell lines and gain-and-loss function experiments verified the oncogenic role of circRHOBTB3. The mechanism of circRHOBTB3 regulatory role was validated by pull-down assays, RIP, luciferase reporter assays. The autophagy response of PANC-1 and MiaPaca-2 cells were detected by mCherry-GFP-LC3B labeling and confocal microscopy, transmission electron microscopy and protein levels of LC3B or p62 via Western blot. Results circRHOBTB3 is highly expressed in PDAC cell lines and tissues, which also promotes PDAC autophagy and then progression in vitro and in vivo. Mechanistically, circRHOBTB3 directly binds to miR-600 and subsequently acts as a miRNA-sponge to maintain the expression level of miR-600-targeted gene NACC1, which facilitates the autophagy response of PDAC cells for adaptation of proliferation via Akt/mTOR pathway. Moreover, the RNA-binding protein FUS (FUS) directly binds to pre-RHOBTB3 mRNA to mediate the biogenesis of circRHOBTB3. Clinically, circRHOBTB3, miR-600 and NACC1 expression levels are correlated with the prognosis of PDAC patients and serve as independent risk factors for PDAC patients. Conclusions FUS-mediated circRHOBTB3 functions as a tumor activator to promote PDAC cell proliferation by modulating miR-600/NACC1/Akt/mTOR axis regulated autophagy.

Circ-0000284 arouses malignant phenotype of cholangiocarcinoma cells and regulates the biological functions of peripheral cells through cellular communication

2019 ◽  
Vol 133 (18) ◽  
pp. 1935-1953 ◽  
Author(s):  
Shuming Wang ◽  
Yilin Hu ◽  
Xiurui Lv ◽  
Bin Li ◽  
Dianhua Gu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Rna Binding ◽  
Direct Interaction ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Biological Functions ◽  
Normal Cells ◽  
Cholangiocarcinoma Cell

Abstract Circular RNAs (circRNAs) play a vital role in cancers. Accumulated evidences showed that the physiological condition of cells can be reflected by the circRNAs in the exosomes they secrete, and these exosomal circRNAs can be captured by the receptor cells, thereby inducing a series of cellular responses. We performed qRT-PCR to detect the expression level of circ-0000284 in cholangiocarcinoma cell lines, tissues and plasma exosomes. Then the direct interaction between circ-0000284 and miR-637 was investigated through dual-luciferase reporter assay, RNA binding protein immunoprecipitation (RIP) assay and Fluorescent in situ hybridization (FISH) assay. Subsequently, EdU (5-ethynyl-2′-deoxyuridine), migration, invasion assay, flow cytometry and nude mouse tumorigenicity assay were adopted to evaluate the effect of circ-0000284 on migration, invasion, proliferation and apoptosis of cholangiocarcinoma cells. Additionally, TEM was conducted to investigate the shape and size of exosomes from cholangiocarcioma and 293T cell lines. Circ-0000284 was evidently elevated in cholangiocarcinoma cell lines, tumor tissues and plasma exosomes. Meanwhile, the high expression of circ-0000284 enhanced the migration, invasion and proliferation abilities of cholangiocarcinoma cells in vivo and in vitro. Besides, the levels of circ-0000284 were increased in cholangiocarcinoma cells and exosomes from them. Moreover, exosomes from cholangiocarcinoma cells enhanced circ-0000284 expression and stimulated migration and proliferation of the surrounding normal cells. Our findings suggest that on the one hand circ-0000284 functions as a competitive endogenous RNA to promote cholangiocarcinoma progression, and on the other hand, circ-0000284 can be directly transferred from cholangiocarcinoma cells to surrounding normal cells via exosomes and in this way regulate the biological functions of surrounding normal cells.

scholarly journals Elevation of miR-302b prevents multiple myeloma cell growth and bone destruction by blocking DKK1 secretion

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zheyu Wu ◽  
Yufeng Zhang ◽  
Zhiqiang Yang ◽  
Yufan Zhu ◽  
Yuanlong Xie ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Western Blot ◽  
Osteogenic Differentiation ◽  
Signaling Pathway ◽  
Bone Destruction ◽  
Bioinformatic Analysis ◽  
Myeloma Cell ◽  
Luciferase Reporter ◽  
Rpmi 8226

Abstract Background Myeloma bone disease (MBD) is a severe complication of multiple myeloma (MM) mainly due to an imbalance between enhanced osteoclast activity and reduced osteoblast function. Previous studies have demonstrated that miRNAs play a vital role in the osteogenic differentiation of mesenchymal stromal cells (MSCs) in MM. However, the value of miR‑302b in MBD remains to be further elucidated. The aim of this study is to explore the role of miR‑302b in the regulation of MBD osteogenic differentiation and evaluate the potential of a new therapeutic strategy for the clinical treatment of MBD. Method Our previous research demonstrated that MiR-302b belongs to the miR-302 cluster and is able to inhibit tumor growth and osteolysis in an orthotopic osteosarcoma xenograft tumor mouse model. In this study, we first transfected miR-302b mimics, miR-302b inhibitor, and miR-302b NC into MM1.S and RPMI8226 MM cells to detect the correlation between miR-302b expression in the pathological specimens and the clinicopathological features by qPCR, the target correlation between miR-302b and DKK1 by immunohistochemistry, qPCR and Western blot, and the correlation between miR-302b and the Wnt/β-catenin signaling pathway by Western blot. The effect of miR-302b on osteoblastogenesis was also studied in a subperiosteal tumorigenesis model of NOD/SCID nude mice. Results We found that increased miR-302b suppressed cell proliferation and induced cell apoptosis in RPMI 8226 and MM1.S cells. TargetScan online bioinformatic analysis predicted that miR-302b is able to bind to 3′UTR of DKK1 mRNA. Target binding of miR-302b to DKK1 was demonstrated by dual-luciferase reporter assay, qPCR, Western blot and immunohistochemistry, indicating that miR-302b is able to degrade DKK1 in RPMI 8226 and MM1.S cells. The model of co-culturing MM cells with preosteoblast MC3T3-E1 cells showed that miR-302b inhibits MM-induced suppression of osteoblast differentiation. Western blotting showed that miR-302b promotes the Wnt/β-catenin signaling pathway in MM cells. Micro-CT and immunohistochemistry results showed that miR-302b suppresses myeloma bone destruction in vivo. Conclusion miR-302b is able to target DKK1 and promote the Wnt/β-catenin signaling pathway in MM.

scholarly journals Naa20, the catalytic subunit of NatB complex, contributes to hepatocellular carcinoma by regulating the LKB1–AMPK–mTOR axis

2020 ◽  
Vol 52 (11) ◽  
pp. 1831-1844
Author(s):  
Taek-Yeol Jung ◽  
Jae-Eun Ryu ◽  
Mi-Mi Jang ◽  
Soh-Yeon Lee ◽  
Gyu-Rin Jin ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Signaling Pathway ◽  
Mammalian Target Of Rapamycin ◽  
Underlying Mechanism ◽  
Bioinformatic Analysis ◽  
Catalytic Subunit ◽  
The Cancer Genome Atlas ◽  
Ampk Activity

AbstractN-α-acetyltransferase 20 (Naa20), which is a catalytic subunit of the N-terminal acetyltransferase B (NatB) complex, has recently been reported to be implicated in hepatocellular carcinoma (HCC) progression and autophagy, but the underlying mechanism remains unclear. Here, we report that based on bioinformatic analysis of Gene Expression Omnibus and The Cancer Genome Atlas data sets, Naa20 expression is much higher in HCC tumors than in normal tissues, promoting oncogenic properties in HCC cells. Mechanistically, Naa20 inhibits the activity of AMP-activated protein kinase (AMPK) to promote the mammalian target of rapamycin signaling pathway, which contributes to cell proliferation, as well as autophagy, through its N-terminal acetyltransferase (NAT) activity. We further show that liver kinase B1 (LKB1), a major regulator of AMPK activity, can be N-terminally acetylated by NatB in vitro, but also probably by NatB and/or other members of the NAT family in vivo, which may have a negative effect on AMPK activity through downregulation of LKB1 phosphorylation at S428. Indeed, p-LKB1 (S428) and p-AMPK levels are enhanced in Naa20-deficient cells, as well as in cells expressing the nonacetylated LKB1-MPE mutant; moreover, importantly, LKB1 deficiency reverses the molecular and cellular events driven by Naa20 knockdown. Taken together, our findings suggest that N-terminal acetylation of LKB1 by Naa20 may inhibit the LKB1–AMPK signaling pathway, which contributes to tumorigenesis and autophagy in HCC.

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