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Dong G, Zhao X, Guo J, Ma L, Zhou H, Liu Q, Zhao X, Wang C, Wu K. Functional expression and purification of recombinant full-length human ATG7 protein with HIV-1 Tat peptide in Escherichia coli. Protein Expr Purif 2021; 182:105844. [PMID: 33592251 DOI: 10.1016/j.pep.2021.105844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/18/2021] [Accepted: 02/09/2021] [Indexed: 01/07/2023]
Abstract
The human autophagy-related protein ATG7 (hATG7), an E1-like ubiquitin enzyme, activates two ubiquitin-like proteins, LC3 (Atg8) and Atg12, and promotes autophagosome formation. While hATG7 plays an essential role for the autophagy conjugation system, the production of full-length functional hATG7 in bacterial systems remains challenging. Previous studies have demonstrated that the HIV-1 virus-encoded Tat peptide ('GRKKRRQRRR') can increase the yield and solubility of heterologous proteins. Here, functional full-length hATG7 was expressed using the pET28b-Tat expression vector in the Escherichia coli BL21 (DE3) strain. Recombinant hATG7 protein aggregated as inclusion bodies while expressed with widely used prokaryotic expression plasmids. In contrast, the solubility of Tat-tagged hATG7 increased significantly with prolonged time compared to Tat-free hATG7. The recombinant proteins were purified to >90% homogeneity under native conditions with a single step of affinity chromatography purification. The results of in vitro pull-down and LC3B-I lipidation assays showed that Tat-tagged hATG7 directly interacted with LC3B-I and promoted LC3B-I lipidation, suggesting that Tat-tagged hATG7 has significant catalytic activity. Overall, this study provides a novel method for improving the functional expression of full-length hATG7 in bacterial systems by fusion with the Tat peptide, a process which may be applied in future studies of hATG7 structure and function.
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Affiliation(s)
- Guofu Dong
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Xi Zhao
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Junwang Guo
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Lei Ma
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Hongmei Zhou
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Qi Liu
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Xuelong Zhao
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China
| | - Changzhen Wang
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China.
| | - Ke Wu
- Beijing Key Laboratory of Radiation Biology (No. BZ0325) and Department of Experimental Pathology, Beijing Institute of Radiation Medicine, Beijing, 100850, China.
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Hu X, Lu Z, Yu S, Reilly J, Liu F, Jia D, Qin Y, Han S, Liu X, Qu Z, Lv Y, Li J, Huang Y, Jiang T, Jia H, Wang Q, Liu J, Shu X, Tang Z, Liu M. CERKL regulates autophagy via the NAD-dependent deacetylase SIRT1. Autophagy 2019; 15:453-465. [PMID: 30205735 PMCID: PMC6351130 DOI: 10.1080/15548627.2018.1520548] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 08/18/2018] [Accepted: 08/22/2018] [Indexed: 01/07/2023] Open
Abstract
Macroautophagy/autophagy is an important intracellular mechanism for the maintenance of cellular homeostasis. Here we show that the CERKL (ceramide kinase like) gene, a retinal degeneration (RD) pathogenic gene, plays a critical role in regulating autophagy by stabilizing SIRT1. In vitro and in vivo, suppressing CERKL results in impaired autophagy. SIRT1 is one of the main regulators of acetylation/deacetylation in autophagy. In CERKL-depleted retinas and cells, SIRT1 is downregulated. ATG5 and ATG7, 2 essential components of autophagy, show a higher degree of acetylation in CERKL-depleted cells. Overexpression of SIRT1 rescues autophagy in CERKL-depleted cells, whereas CERKL loses its function of regulating autophagy in SIRT1-depleted cells, and overexpression of CERKL upregulates SIRT1. Finally, we show that CERKL directly interacts with SIRT1, and may regulate its phosphorylation at Ser27 to stabilize SIRT1. These results show that CERKL is an important regulator of autophagy and it plays this role by stabilizing the deacetylase SIRT1.
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Affiliation(s)
- Xuebin Hu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Zhaojing Lu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Shanshan Yu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - James Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Fei Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Danna Jia
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Yayun Qin
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Shanshan Han
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
- Department of Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Xiliang Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Zhen Qu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Jingzhen Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Tao Jiang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Haibo Jia
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Qing Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Jingyu Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow, UK
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Department of Genetics and Developmental Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, P.R. China
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Nuta GC, Gilad Y, Gershoni M, Sznajderman A, Schlesinger T, Bialik S, Eisenstein M, Pietrokovski S, Kimchi A. A cancer associated somatic mutation in LC3B attenuates its binding to E1-like ATG7 protein and subsequent lipidation. Autophagy 2019; 15:438-452. [PMID: 30238850 PMCID: PMC6351123 DOI: 10.1080/15548627.2018.1525476] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 08/30/2018] [Accepted: 09/14/2018] [Indexed: 02/01/2023] Open
Abstract
Macroautophagy/autophagy is a conserved catabolic process that maintains cellular homeostasis under basal growth and stress conditions. In cancer, autophagy can either prevent or promote tumor growth, at early or advanced stages, respectively. We screened public databases to identify autophagy-related somatic mutations in cancer, using a computational approach to identify cancer mutational target sites, employing exact statistics. The top significant hit was a missense mutation (Y113C) in the MAP1LC3B/LC3B (microtubule associated protein 1 light chain 3 beta) protein, which occurred at a significant frequency in cancer, and was detected in early stages in primary tumors of patients with known tumor lineage. The mutation reduced the formation of GFP-LC3B puncta and attenuated LC3B lipidation during Torin1-induced autophagy. Its effect on the direct physical interaction of LC3B with each of the 4 proteins that control its maturation or lipidation was tested by applying a protein-fragment complementation assay and co-immunoprecipitation experiments. Interactions with ATG4A and ATG4B proteases were reduced, yet without perturbing the cleavage of mutant LC3B. Most importantly, the mutation significantly reduced the interaction with the E1-like enzyme ATG7, but not the direct interaction with the E2-like enzyme ATG3, suggesting a selective perturbation in the binding of LC3B to some of its partner proteins. Structure analysis and molecular dynamics simulations of LC3B protein and its mutant suggest that the mutation changes the conformation of a loop that has several contact sites with ATG4B and the ATG7 homodimer. We suggest that this loss-of-function mutation, which attenuates autophagy, may promote early stages of cancer development.
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Affiliation(s)
- Gal Chaim Nuta
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Yuval Gilad
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Moran Gershoni
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Arielle Sznajderman
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Tomer Schlesinger
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Shani Bialik
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Miriam Eisenstein
- Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Shmuel Pietrokovski
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Adi Kimchi
- Departments of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
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4
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Nitta A, Hori K, Tanida I, Igarashi A, Deyama Y, Ueno T, Kominami E, Sugai M, Aoki K. Blocking LC3 lipidation and ATG12 conjugation reactions by ATG7 mutant protein containing C572S. Biochem Biophys Res Commun 2019; 508:521-526. [PMID: 30503495 DOI: 10.1016/j.bbrc.2018.11.158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 11/24/2018] [Indexed: 12/30/2022]
Abstract
Autophagy, a system for the bulk degradation of intracellular components, is essential for homeostasis and the healthy physiology and development of cells and tissues. Its deregulation is associated with human disease. Thus, methods to modulate autophagic activity are critical for analysis of its role in mammalian cells and tissues. Here we report a method to inhibit autophagy using a mutant variant of the protein ATG7, a ubiquitin E1-like enzyme essential for autophagosome formation. During autophagy, ATG7 activates the conjugation of LC3 (ATG8) with phosphatidylethanolamine (PE) and ATG12 with ATG5. Human ATG7 interactions with LC3 or ATG12 require a thioester bond involving the ATG7 cysteine residue at position 572. We generated TetOff cells expressing mutant ATG7 protein carrying a serine substitution of this critical cysteine residue (ATG7C572S). Because ATG7C572S forms stable intermediate complexes with LC3 or ATG12, its expression resulted in a strong blockage of the ATG-conjugation system and suppression of autophagosome formation. Consequently, ATG7C572S mutant protein can be used as an inhibitor of autophagy.
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Affiliation(s)
- Akari Nitta
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Kazuya Hori
- Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Isei Tanida
- Department of Cell Biology and Neuroscience, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Ayumi Igarashi
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Yasuyo Deyama
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Takashi Ueno
- Laboratory of Proteomics and Biomolecular Science, Research Support Center, Juntendo University Graduate School of Medicine, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Eiki Kominami
- Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Manabu Sugai
- Department of Molecular Genetics, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan
| | - Koji Aoki
- The Aoki Laboratory, Life Science Unit, Tenure-Track Program for Innovative Research, University of Fukui 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Department of Pharmacology, Unit of Biochemistry and Bioinformative Sciences, Faculty of Medicine, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; Life Science Innovation Center, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan; PREST, Japan Science and Technology Agency, 5-7 Chiyoda-ku, Tokyo, 102-0076, Japan.
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5
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Ogmundsdottir MH, Fock V, Sooman L, Pogenberg V, Dilshat R, Bindesbøll C, Ogmundsdottir HM, Simonsen A, Wilmanns M, Steingrimsson E. A short isoform of ATG7 fails to lipidate LC3/GABARAP. Sci Rep 2018; 8:14391. [PMID: 30258106 PMCID: PMC6158294 DOI: 10.1038/s41598-018-32694-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/10/2018] [Indexed: 12/13/2022] Open
Abstract
Autophagy is a degradation pathway important for cellular homeostasis. The E1-like enzyme ATG7 is a key component of the autophagy machinery, with the main function of mediating the lipidation of LC3/GABARAP during autophagosome formation. By analysing mRNA-sequencing data we found that in addition to the full-length ATG7 isoform, various tissues express a shorter isoform lacking an exon of 27 amino acids in the C-terminal part of the protein, termed ATG7(2). We further show that ATG7(2) does not bind LC3B and fails to mediate the lipidation of members of the LC3/GABARAP family. We have thus identified an isoform of ATG7 that is unable to carry out the best characterized function of the protein during the autophagic response. This short isoform will have to be taken into consideration when further studying the role of ATG7.
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Affiliation(s)
- M H Ogmundsdottir
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland.
| | - V Fock
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - L Sooman
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - V Pogenberg
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607, Hamburg, Germany
| | - R Dilshat
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - C Bindesbøll
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Sognsvannsveien 9, N-0317, Oslo, Norway
| | - H M Ogmundsdottir
- Cancer Research Laboratory, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland
| | - A Simonsen
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Sognsvannsveien 9, N-0317, Oslo, Norway
| | - M Wilmanns
- European Molecular Biology Laboratory, Hamburg Unit, Notkestrasse 85, 22607, Hamburg, Germany
| | - E Steingrimsson
- Department of Biochemistry and Molecular Biology, Biomedical Center, Faculty of Medicine, University of Iceland, Sturlugata 8, 101, Reykjavik, Iceland.
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Gao AM, Zhang XY, Hu JN, Ke ZP. Apigenin sensitizes hepatocellular carcinoma cells to doxorubic through regulating miR-520b/ATG7 axis. Chem Biol Interact 2018; 280:45-50. [PMID: 29191453 DOI: 10.1016/j.cbi.2017.11.020] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/14/2017] [Accepted: 11/26/2017] [Indexed: 12/16/2022]
Abstract
Chemo-resistance is a serious obstacle for successful treatment of cancer. Apigenin, a dietary flavonoid, has been reported as an anticancer drug in various malignant cancers. This study aimed to investigate the potential chemo-sensitization effect of apigenin in doxorubicin-resistant hepatocellular carcinoma cell line BEL-7402/ADM. We observed that apigenin significantly enhanced doxorubicin sensitivity, induced miR-520b expression and inhibited ATG7-dependent autophagy in BEL-7402/ADM cells. In addition, we also showed that miR-520b mimics increased doxorubicin sensitivity and inhibited ATG7-dependent autophagy. Meanwhile, we indicated that ATG7 was a potential target of miR-520b. Furthermore, APG inhibited the growth of hepatocellar carcinoma xenografts in nude mice by up-regulating miR-520b and inhibiting ATG7. Our finding provides evidence that apigenin sensitizes BEL-7402/ADM cells to doxorubicin through miR-520b/ATG7 pathway, which furtherly supports apigenin as a potential chemo-sensitizer for hepatocellular carcinoma.
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Affiliation(s)
- Ai-Mei Gao
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; Department of Pharmacy, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Xiao-Yu Zhang
- Division of Gastrointestinal Surgery, Department of General Surgery, Huai'an Second People's Hospital, The Affiliated Huai'an Hospital of Xuzhou Medical University, Huai'an 223001, China
| | - Juan-Ni Hu
- Department of Clinical Pharmacy, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Zun-Ping Ke
- Department of Cardiology, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai 200240, China.
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