UHRF1对肝癌干细胞的调控作用及机制研究

在世界范围内，肝癌是第三大癌症的死亡诱因。原发性肝癌包括肝细胞癌（占病例的75%-85%）、肝内胆管癌（10%-15%），以及其他罕见类型。肝癌具有发病早期隐蔽、转移性强、高复发率的特点。肝癌的靶向药物如索拉非尼，乐伐替尼等仍然面临着患者响应率低，生存期延缓效果不佳等问题，当前仍然缺乏行之有效的治疗方法。在包括肝细胞癌在内的许多类型的癌症中，肿瘤干细胞被认为是肿瘤的发生、进展和复发的源头。肿瘤干细胞的表观遗传重编程（包括DNA甲基化重编程）已成为诱导肿瘤从恶性到良性转变的一种有前景的治疗策略。泛素样含有PHD和无名指结构域1（Ubiquitin Like With PHD And Ring Finger Domains 1，UHRF1）作为一种表观遗传修饰蛋白，是维持基因组的甲基化所必需的，然而UHRF1在肝癌及肿瘤干细胞中的作用及机制仍未被完全阐明，因此探明UHRF1在肝癌发生及发展中的作用将有助于理解表观遗传修饰DNA甲基化在肿瘤中所扮演的角色，也将有助于开发靶向DNA甲基化的肝癌治疗手段。

本文以肝脏特异性敲除UHRF1基因的小鼠为体内研究对象，利用二乙基亚硝胺、四氯化碳诱导的肝癌模型及MYC基因驱动的肝癌模型探究UHRF1在肝癌发生及发展过程中的作用。结果显示在小鼠肝脏中敲除UHRF1抑制了小鼠肝癌的成瘤率（两模型中均由对照组的100%成瘤率降为UHRF1敲除组的50%），并延缓了肿瘤进展的速率。在MYC基因驱动的肝癌模型中应用UHRF1抑制剂使癌灶数量下降了约50%。对小鼠肝脏转录组测序结果进行差异基因分析及通路富集分析，结果显示在UHRF1敲除组中下调的基因富集到了关键干性调控通路-Wnt通路。蛋白质印迹实验检测发现，随着肝癌的进展对照组小鼠肝脏中肿瘤干细胞标记物CD44和CD133的蛋白量有逐步上升的趋势，免疫荧光实验同样检测到CD44和CD133蛋白表达阳性的细胞比例在不断升高（7个月时分别约为50%和70%）；而在敲除UHRF1的小鼠肝脏中只观察到很少的CD44和CD133阳性细胞（7个月时分别约为10%和2%）。这些结果揭示了 UHRF1 在维持肝癌细胞的肿瘤特征及干性方面的重要功能。

本文利用敲低及过表达UHRF1的肝癌细胞系在体外进一步探究了UHRF1的功能及其作用机制。结果显示过表达UHRF1对肿瘤细胞没有明显影响，而敲低UHRF1对肝癌细胞的增殖及迁移能力有显著的抑制；重要的是，肝癌细胞系的干性成球率在敲低UHRF1后降低约50%；不仅如此，CD44和CD133双阳性的细胞比例也在敲低UHRF1的细胞中下降约60%。转录组测序和全基因组甲基化测序的联合分析显示UHRF1的敲低诱导了基因组广泛的低甲基化，并在表观修饰水平重编程了癌细胞使其分化并转变为“良性肿瘤”。机制上来说，UHRF1的缺失上调了转录因子CCAAT Enhancer Binding Protein Alpha（CEBPA）的表达，上调的CEBPA抑制了干性基因胶质瘤相关癌基因1（Glioma-Associated Oncogene 1，GLI1）的转录，同时抑制了干性调控通路的信号传导。这些结果阐明了 UHRF1-CEBPA-GLI1 信号传导轴对肝癌干细胞的重要调控作用。

对于临床肝癌患者，UHRF1的mRNA表达量及蛋白水平在癌组织中比癌旁组织中更高，且UHRF1在癌组织中的高表达与患者预后差相关。具有病理生理意义的是，UHRF1、CD44、CD133和GLI1的蛋白水平在肝癌患者癌组织中表达模式相似。肝癌患者中的检测结果强调了UHRF1在不同个体中参与调控肿瘤干性的机制具有一致性。除此之外，UHRF1的抑制剂显著地抑制了小鼠肝癌的进展提示了靶向UHRF1治疗肝癌的可能。

综上所述，本研究分别在体内体外探明了 UHRF1 对于维持肝癌细胞的肿瘤特征及干性的重要功能，并阐明了调控机制。本研究为DNA甲基化参与调控肿瘤干性的研究打下了理论基础，并对肝细胞癌治疗策略的发展具有重要意义。

[1] SUNG H, FERLAY J, SIEGEL R L, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries [J]. CA Cancer J Clin, 2021, 71(3): 209-249.
[2] BRAY F, FERLAY J, SOERJOMATARAM I, et al. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries [J]. CA Cancer J Clin, 2018, 68(6): 394-424.
[3] AYUSO C, RIMOLA J, VILANA R, et al. Diagnosis and staging of hepatocellular carcinoma (HCC): current guidelines [J]. Eur J Radiol, 2018, 101: 72-81.
[4] NAM A S, CHALIGNE R, LANDAU D A. Integrating genetic and non-genetic determinants of cancer evolution by single-cell multi-omics [J]. Nat Rev Genet, 2021, 22(1): 3-18.
[5] CASADO-PELAEZ M, BUENO-COSTA A, ESTELLER M. Single cell cancer epigenetics [J]. Trends Cancer, 2022, 8(10): 820-838.
[6] HANAHAN D. Hallmarks of Cancer: New Dimensions [J]. Cancer Discov, 2022, 12(1): 31-46.
[7] ASHRAF W, IBRAHIM A, ALHOSIN M, et al. The epigenetic integrator UHRF1: on the road to become a universal biomarker for cancer [J]. Oncotarget, 2017, 8(31): 51946-51962.
[8] NISHIYAMA A, NAKANISHI M. Navigating the DNA methylation landscape of cancer [J]. Trends Genet, 2021, 37(11): 1012-1027.
[9] SKVORTSOVA K, STIRZAKER C, TABERLAY P. The DNA methylation landscape in cancer [J]. Essays Biochem, 2019, 63(6): 797-811.
[10] TORRE L A, BRAY F, SIEGEL R L, et al. Global cancer statistics, 2012 [J]. CA Cancer J Clin, 2015, 65(2): 87-108.
[11] GANESAN P, KULIK L M. Hepatocellular Carcinoma: New Developments [J]. Clin Liver Dis, 2023, 27(1): 85-102.
[12] NAGARAJU G P, DARIYA B, KASA P, et al. Epigenetics in hepatocellular carcinoma [J]. Semin Cancer Biol, 2022, 86(Pt 3): 622-632.
[13] LLOVET J M, KELLEY R K, VILLANUEVA A, et al. Hepatocellular carcinoma [J]. Nat Rev Dis Primers, 2021, 7(1): 6.
[14] KULIK L, EL-SERAG H B. Epidemiology and Management of Hepatocellular Carcinoma [J]. Gastroenterology, 2019, 156(2): 477-491.e471.
[15] NJEI B, ROTMAN Y, DITAH I, et al. Emerging trends in hepatocellular carcinoma incidence and mortality [J]. Hepatology, 2015, 61(1): 191-199.
[16] REBOUISSOU S, NAULT J C. Advances in molecular classification and precision oncology in hepatocellular carcinoma [J]. J Hepatol, 2020, 72(2): 215-229.
[17] SINGAL A G, KANWAL F, LLOVET J M. Global trends in hepatocellular carcinoma epidemiology: implications for screening, prevention and therapy [J]. Nat Rev Clin Oncol, 2023, 20(12): 864-884.
[18] GUTIéRREZ-CUEVAS J, LUCANO-LANDEROS S, LóPEZ-CIFUENTES D, et al. Epidemiologic, Genetic, Pathogenic, Metabolic, Epigenetic Aspects Involved in NASH-HCC: Current Therapeutic Strategies [J]. Cancers (Basel), 2022, 15(1).
[19] MARENGO A, ROSSO C, BUGIANESI E. Liver Cancer: Connections with Obesity, Fatty Liver, and Cirrhosis [J]. Annu Rev Med, 2016, 67: 103-117.
[20] CALDERARO J, SERAPHIN T P, LUEDDE T, et al. Artificial intelligence for the prevention and clinical management of hepatocellular carcinoma [J]. J Hepatol, 2022, 76(6): 1348-1361.
[21] LU T, SETO W K, ZHU R X, et al. Prevention of hepatocellular carcinoma in chronic viral hepatitis B and C infection [J]. World J Gastroenterol, 2013, 19(47): 8887-8894.
[22] YANG J D, HEIMBACH J K. New advances in the diagnosis and management of hepatocellular carcinoma [J]. Bmj, 2020, 371: m3544.
[23] FENG M, PAN Y, KONG R, et al. Therapy of Primary Liver Cancer [J]. Innovation (Camb), 2020, 1(2): 100032.
[24] FORNER A, REIG M, BRUIX J. Hepatocellular carcinoma [J]. Lancet, 2018, 391(10127): 1301-1314.
[25] NIO K, YAMASHITA T, KANEKO S. The evolving concept of liver cancer stem cells [J]. Mol Cancer, 2017, 16(1): 4.
[26] TSUCHIYA H, SHIOTA G. Clinical and Biological Implications of Cancer Stem Cells in Hepatocellular Carcinoma [J]. Yonago Acta Med, 2021, 64(1): 1-11.
[27] LEE T K, CASTILHO A, CHEUNG V C, et al. CD24(+) liver tumor-initiating cells drive self-renewal and tumor initiation through STAT3-mediated NANOG regulation [J]. Cell Stem Cell, 2011, 9(1): 50-63.
[28] SUETSUGU A, NAGAKI M, AOKI H, et al. Characterization of CD133+ hepatocellular carcinoma cells as cancer stem/progenitor cells [J]. Biochem Biophys Res Commun, 2006, 351(4): 820-824.
[29] ZHOU L, YU K H, WONG T L, et al. Lineage tracing and single-cell analysis reveal proliferative Prom1+ tumour-propagating cells and their dynamic cellular transition during liver cancer progression [J]. Gut, 2022, 71(8): 1656-1668.
[30] ZHU Z, HAO X, YAN M, et al. Cancer stem/progenitor cells are highly enriched in CD133+CD44+ population in hepatocellular carcinoma [J]. Int J Cancer, 2010, 126(9): 2067-2078.
[31] MA S, LEE T K, ZHENG B J, et al. CD133+ HCC cancer stem cells confer chemoresistance by preferential expression of the Akt/PKB survival pathway [J]. Oncogene, 2008, 27(12): 1749-1758.
[32] LEE D, NA J, RYU J, et al. Interaction of tetraspan(in) TM4SF5 with CD44 promotes self-renewal and circulating capacities of hepatocarcinoma cells [J]. Hepatology, 2015, 61(6): 1978-1997.
[33] XU C, XU Z, ZHANG Y, et al. β-Catenin signaling in hepatocellular carcinoma [J]. J Clin Invest, 2022, 132(4).
[34] DING J, LI H Y, ZHANG L, et al. Hedgehog Signaling, a Critical Pathway Governing the Development and Progression of Hepatocellular Carcinoma [J]. Cells, 2021, 10(1).
[35] JENG K S, CHANG C F, SHEEN I S, et al. Cellular and Molecular Biology of Cancer Stem Cells of Hepatocellular Carcinoma [J]. International journal of molecular sciences, 2023, 24(2).
[36] MACDONALD B T, TAMAI K, HE X. Wnt/beta-catenin signaling: components, mechanisms, and diseases [J]. Dev Cell, 2009, 17(1): 9-26.
[37] LUO J, WANG P, WANG R, et al. The Notch pathway promotes the cancer stem cell characteristics of CD90+ cells in hepatocellular carcinoma [J]. Oncotarget, 2016, 7(8): 9525-9537.
[38] ZHANG Q, LU C, FANG T, et al. Notch3 functions as a regulator of cell self-renewal by interacting with the β-catenin pathway in hepatocellular carcinoma [J]. Oncotarget, 2015, 6(6): 3669-3679.
[39] ZHU P, WANG Y, DU Y, et al. C8orf4 negatively regulates self-renewal of liver cancer stem cells via suppression of NOTCH2 signalling [J]. Nat Commun, 2015, 6: 7122.
[40] HANNA A, SHEVDE L A. Hedgehog signaling: modulation of cancer properies and tumor mircroenvironment [J]. Mol Cancer, 2016, 15: 24.
[41] RIMKUS T K, CARPENTER R L, QASEM S, et al. Targeting the Sonic Hedgehog Signaling Pathway: Review of Smoothened and GLI Inhibitors [J]. Cancers (Basel), 2016, 8(2).
[42] YAMANAKA S. Induced pluripotent stem cells: past, present, and future [J]. Cell Stem Cell, 2012, 10(6): 678-684.
[43] ZHENG Y W, NIE Y Z, TANIGUCHI H. Cellular reprogramming and hepatocellular carcinoma development [J]. World J Gastroentero, 2013, 19(47): 8850-8860.
[44] SUVà M L, RIGGI N, BERNSTEIN B E. Epigenetic reprogramming in cancer [J]. Science, 2013, 339(6127): 1567-1570.
[45] DAS P K, PILLAI S, RAKIB M A, et al. Plasticity of Cancer Stem Cell: Origin and Role in Disease Progression and Therapy Resistance [J]. Stem Cell Rev Rep, 2020, 16(2): 397-412.
[46] WANG Y, CARDENAS H, FANG F, et al. Epigenetic targeting of ovarian cancer stem cells [J]. Cancer Res, 2014, 74(17): 4922-4936.
[47] FAN C, KAM S, RAMADORI P. Metabolism-Associated Epigenetic and Immunoepigenetic Reprogramming in Liver Cancer [J]. Cancers (Basel), 2021, 13(20).
[48] BIRD A. Perceptions of epigenetics [J]. Nature, 2007, 447(7143): 396-398.
[49] Comprehensive and Integrative Genomic Characterization of Hepatocellular Carcinoma [J]. Cell, 2017, 169(7): 1327-1341.e1323.
[50] LIU Y, LIANG G, XU H, et al. Tumors exploit FTO-mediated regulation of glycolytic metabolism to evade immune surveillance [J]. Cell Metab, 2021, 33(6): 1221-1233.e1211.
[51] RASMUSSEN K D, HELIN K. Role of TET enzymes in DNA methylation, development, and cancer [J]. Genes Dev, 2016, 30(7): 733-750.
[52] GREENBERG M V C, BOURC'HIS D. The diverse roles of DNA methylation in mammalian development and disease [J]. Nat Rev Mol Cell Biol, 2019, 20(10): 590-607.
[53] HORVATH S, RAJ K. DNA methylation-based biomarkers and the epigenetic clock theory of ageing [J]. Nat Rev Genet, 2018, 19(6): 371-384.
[54] YOUSEFI P D, SUDERMAN M, LANGDON R, et al. DNA methylation-based predictors of health: applications and statistical considerations [J]. Nat Rev Genet, 2022, 23(6): 369-383.
[55] YAN R, CHENG X, GU C, et al. Dynamics of DNA hydroxymethylation and methylation during mouse embryonic and germline development [J]. Nat Genet, 2023, 55(1): 130-143.
[56] FENG S, COKUS S J, ZHANG X, et al. Conservation and divergence of methylation patterning in plants and animals [J]. Proc Natl Acad Sci U S A, 2010, 107(19): 8689-8694.
[57] GUO P, ZHENG H, LI Y, et al. Hepatocellular carcinoma detection via targeted enzymatic methyl sequencing of plasma cell-free DNA [J]. Clin Epigenetics, 2023, 15(1): 2.
[58] LO Y M D, HAN D S C, JIANG P, et al. Epigenetics, fragmentomics, and topology of cell-free DNA in liquid biopsies [J]. Science, 2021, 372(6538).
[59] WEBER M, HELLMANN I, STADLER M B, et al. Distribution, silencing potential and evolutionary impact of promoter DNA methylation in the human genome [J]. Nat Genet, 2007, 39(4): 457-466.
[60] SCHüBELER D. Function and information content of DNA methylation [J]. Nature, 2015, 517(7534): 321-326.
[61] CHENG X, BLUMENTHAL R M. Mediating and maintaining methylation while minimizing mutation: Recent advances on mammalian DNA methyltransferases [J]. Curr Opin Struct Biol, 2022, 75: 102433.
[62] DEL CASTILLO FALCONI V M, TORRES-ARCIGA K, MATUS-ORTEGA G, et al. DNA Methyltransferases: From Evolution to Clinical Applications [J]. International journal of molecular sciences, 2022, 23(16).
[63] MAN X, LI Q, WANG B, et al. DNMT3A and DNMT3B in Breast Tumorigenesis and Potential Therapy [J]. Front Cell Dev Biol, 2022, 10: 916725.
[64] SHARIF J, MUTO M, TAKEBAYASHI S, et al. The SRA protein Np95 mediates epigenetic inheritance by recruiting Dnmt1 to methylated DNA [J]. Nature, 2007, 450(7171): 908-912.
[65] MATTEI A L, BAILLY N, MEISSNER A. DNA methylation: a historical perspective [J]. Trends Genet, 2022, 38(7): 676-707.
[66] DAURA-OLLER E, CABRE M, MONTERO M A, et al. Specific gene hypomethylation and cancer: new insights into coding region feature trends [J]. Bioinformation, 2009, 3(8): 340-343.
[67] CHEN Z, ZHANG Y. Role of Mammalian DNA Methyltransferases in Development [J]. Annu Rev Biochem, 2020, 89: 135-158.
[68] VALENTE A, VIEIRA L, SILVA M J, et al. The Effect of Nanomaterials on DNA Methylation: A Review [J]. Nanomaterials (Basel), 2023, 13(12).
[69] BOSTICK M, KIM J K, ESTèVE P O, et al. UHRF1 plays a role in maintaining DNA methylation in mammalian cells [J]. Science, 2007, 317(5845): 1760-1764.
[70] ITO S, SHEN L, DAI Q, et al. Tet proteins can convert 5-methylcytosine to 5-formylcytosine and 5-carboxylcytosine [J]. Science, 2011, 333(6047): 1300-1303.
[71] WU X, ZHANG Y. TET-mediated active DNA demethylation: mechanism, function and beyond [J]. Nat Rev Genet, 2017, 18(9): 517-534.
[72] WU H, ZHANG Y. Reversing DNA methylation: mechanisms, genomics, and biological functions [J]. Cell, 2014, 156(1-2): 45-68.
[73] HAGGERTY C, KRETZMER H, RIEMENSCHNEIDER C, et al. Dnmt1 has de novo activity targeted to transposable elements [J]. Nat Struct Mol Biol, 2021, 28(7): 594-603.
[74] BRAY J K, DAWLATY M M, VERMA A, et al. Roles and Regulations of TET Enzymes in Solid Tumors [J]. Trends Cancer, 2021, 7(7): 635-646.
[75] AL-YOZBAKI M, JABRE I, SYED N H, et al. Targeting DNA methyltransferases in non-small-cell lung cancer [J]. Semin Cancer Biol, 2022, 83: 77-87.
[76] GIRI A K, AITTOKALLIO T. DNMT Inhibitors Increase Methylation in the Cancer Genome [J]. Front Pharmacol, 2019, 10: 385.
[77] ANSARI I, CHATURVEDI A, CHITKARA D, et al. CRISPR/Cas mediated epigenome editing for cancer therapy [J]. Semin Cancer Biol, 2022, 83: 570-583.
[78] BRONNER C, ALHOSIN M, HAMICHE A, et al. Coordinated Dialogue between UHRF1 and DNMT1 to Ensure Faithful Inheritance of Methylated DNA Patterns [J]. Genes (Basel), 2019, 10(1).
[79] BASHTRYKOV P, JANKEVICIUS G, JURKOWSKA R Z, et al. The UHRF1 protein stimulates the activity and specificity of the maintenance DNA methyltransferase DNMT1 by an allosteric mechanism [J]. J Biol Chem, 2014, 289(7): 4106-4115.
[80] BERKYUREK A C, SUETAKE I, ARITA K, et al. The DNA methyltransferase Dnmt1 directly interacts with the SET and RING finger-associated (SRA) domain of the multifunctional protein Uhrf1 to facilitate accession of the catalytic center to hemi-methylated DNA [J]. J Biol Chem, 2014, 289(1): 379-386.
[81] ARITA K, ARIYOSHI M, TOCHIO H, et al. Recognition of hemi-methylated DNA by the SRA protein UHRF1 by a base-flipping mechanism [J]. Nature, 2008, 455(7214): 818-821.
[82] FANG J, CHENG J, WANG J, et al. Hemi-methylated DNA opens a closed conformation of UHRF1 to facilitate its histone recognition [J]. Nat Commun, 2016, 7: 11197.
[83] QIN W, WOLF P, LIU N, et al. DNA methylation requires a DNMT1 ubiquitin interacting motif (UIM) and histone ubiquitination [J]. Cell Res, 2015, 25(8): 911-929.
[84] HAN M, LI J, CAO Y, et al. A role for LSH in facilitating DNA methylation by DNMT1 through enhancing UHRF1 chromatin association [J]. Nucleic Acids Res, 2020, 48(21): 12116-12134.
[85] HAHM J Y, PARK J W, KANG J Y, et al. Acetylation of UHRF1 Regulates Hemi-methylated DNA Binding and Maintenance of Genome-wide DNA Methylation [J]. Cell reports, 2020, 32(4): 107958.
[86] LIN Y, CHEN Z, ZHENG Y, et al. MiR-506 Targets UHRF1 to Inhibit Colorectal Cancer Proliferation and Invasion via the KISS1/PI3K/NF-kappaB Signaling Axis [J]. Front Cell Dev Biol, 2019, 7: 266.
[87] TANIUE K, HAYASHI T, KAMOSHIDA Y, et al. UHRF1-KAT7-mediated regulation of TUSC3 expression via histone methylation/acetylation is critical for the proliferation of colon cancer cells [J]. Oncogene, 2020, 39(5): 1018-1030.
[88] KONG X, CHEN J, XIE W, et al. Defining UHRF1 Domains that Support Maintenance of Human Colon Cancer DNA Methylation and Oncogenic Properties [J]. Cancer Cell, 2019, 35(4): 633-648 e637.
[89] HE H, LEE C, KIM J K. UHRF1 depletion sensitizes retinoblastoma cells to chemotherapeutic drugs via downregulation of XRCC4 [J]. Cell Death Dis, 2018, 9(2): 164.
[90] YAN F, SHAO L J, HU X Y. Knockdown of UHRF1 by lentivirus-mediated shRNA inhibits ovarian cancer cell growth [J]. Asian Pac J Cancer Prev, 2015, 16(4): 1343-1348.
[91] JIAO D, HUAN Y, ZHENG J, et al. UHRF1 promotes renal cell carcinoma progression through epigenetic regulation of TXNIP [J]. Oncogene, 2019, 38(28): 5686-5699.
[92] JIN W, CHEN L, CHEN Y, et al. UHRF1 is associated with epigenetic silencing of BRCA1 in sporadic breast cancer [J]. Breast Cancer Res Treat, 2010, 123(2): 359-373.
[93] WU J E, WU Y Y, TUNG C H, et al. DNA methylation maintains the CLDN1-EPHB6-SLUG axis to enhance chemotherapeutic efficacy and inhibit lung cancer progression [J]. Theranostics, 2020, 10(19): 8903-8923.
[94] KOSTYRKO K, ROMáN M, LEE A G, et al. UHRF1 is a mediator of KRAS driven oncogenesis in lung adenocarcinoma [J]. Nat Commun, 2023, 14(1): 3966.
[95] KIM J H, SHIM J W, EUM D Y, et al. Downregulation of UHRF1 increases tumor malignancy by activating the CXCR4/AKT-JNK/IL-6/Snail signaling axis in hepatocellular carcinoma cells [J]. Scientific reports, 2017, 7(1): 2798.
[96] LIU X, OU H, XIANG L, et al. Elevated UHRF1 expression contributes to poor prognosis by promoting cell proliferation and metastasis in hepatocellular carcinoma [J]. Oncotarget, 2017, 8(6): 10510-10522.
[97] BECK A, TRIPPEL F, WAGNER A, et al. Overexpression of UHRF1 promotes silencing of tumor suppressor genes and predicts outcome in hepatoblastoma [J]. Clin Epigenetics, 2018, 10: 27.
[98] FANG T, JIAO Z, YOU Y, et al. Lenvatinib inhibited HCC cell migration and invasion through regulating the transcription and ubiquitination of UHRF1 and DNMT1 [J]. Biochem Pharmacol, 2023: 115489.
[99] BARCENA-VARELA M, CARUSO S, LLERENA S, et al. Dual Targeting of Histone Methyltransferase G9a and DNA-Methyltransferase 1 for the Treatment of Experimental Hepatocellular Carcinoma [J]. Hepatology, 2019, 69(2): 587-603.
[100] KIM K Y, TANAKA Y, SU J, et al. Uhrf1 regulates active transcriptional marks at bivalent domains in pluripotent stem cells through Setd1a [J]. Nat Commun, 2018, 9(1): 2583.
[101] XIANG H, YUAN L, GAO X, et al. UHRF1 is required for basal stem cell proliferation in response to airway injury [J]. Cell Discov, 2017, 3: 17019.
[102] ZHAO J, CHEN X, SONG G, et al. Uhrf1 controls the self-renewal versus differentiation of hematopoietic stem cells by epigenetically regulating the cell-division modes [J]. Proc Natl Acad Sci U S A, 2017, 114(2): E142-E151.
[103] WU Y, DUAN P, WEN Y, et al. UHRF1 establishes crosstalk between somatic and germ cells in male reproduction [J]. Cell Death Dis, 2022, 13(4): 377.
[104] ZHOU S, DONG J, XIONG M, et al. UHRF1 interacts with snRNAs and regulates alternative splicing in mouse spermatogonial stem cells [J]. Stem Cell Reports, 2022, 17(8): 1859-1873.
[105] HU C L, CHEN B Y, LI Z, et al. Targeting UHRF1-SAP30-MXD4 axis for leukemia initiating cell eradication in myeloid leukemia [J]. Cell Res, 2022, 32(12): 1105-1123.
[106] MUDBHARY R, HOSHIDA Y, CHERNYAVSKAYA Y, et al. UHRF1 overexpression drives DNA hypomethylation and hepatocellular carcinoma [J]. Cancer Cell, 2014, 25(2): 196-209.
[107] MAGNANI E, MACCHI F, MADAKASHIRA B P, et al. uhrf1 and dnmt1 Loss Induces an Immune Response in Zebrafish Livers Due to Viral Mimicry by Transposable Elements [J]. Front Immunol, 2021, 12: 627926.
[108] WANG S, ZHANG C, HASSON D, et al. Epigenetic Compensation Promotes Liver Regeneration [J]. Dev Cell, 2019, 50(1): 43-56.e46.
[109] KüHN R, TORRES R M. Cre/loxP recombination system and gene targeting [J]. Methods Mol Biol, 2002, 180: 175-204.
[110] WANG T, CHEN X, WANG K, et al. Cre-loxP-mediated genetic lineage tracing: Unraveling cell fate and origin in the developing heart [J]. Front Cardiovasc Med, 2023, 10: 1085629.
[111] UEHARA T, POGRIBNY I P, RUSYN I. The DEN and CCl(4) -Induced Mouse Model of Fibrosis and Inflammation-Associated Hepatocellular Carcinoma [J]. Curr Protoc, 2021, 1(8): e211.
[112] ZHAN T, RINDTORFF N, BOUTROS M. Wnt signaling in cancer [J]. Oncogene, 2017, 36(11): 1461-1473.
[113] ZHANG Y, WANG X. Targeting the Wnt/β-catenin signaling pathway in cancer [J]. J Hematol Oncol, 2020, 13(1): 165.
[114] DHANASEKARAN R, DEUTZMANN A, MAHAUAD-FERNANDEZ W D, et al. The MYC oncogene - the grand orchestrator of cancer growth and immune evasion [J]. Nat Rev Clin Oncol, 2022, 19(1): 23-36.
[115] PARK S, SATER A H A, FAHRMANN J F, et al. Novel UHRF1-MYC Axis in Acute Lymphoblastic Leukemia [J]. Cancers (Basel), 2022, 14(17).
[116] FRANKS J L, MARTINEZ-CHACIN R C, WANG X, et al. In silico APC/C substrate discovery reveals cell cycle-dependent degradation of UHRF1 and other chromatin regulators [J]. PLoS Biol, 2020, 18(12): e3000975.
[117] MANCINI M, MAGNANI E, MACCHI F, et al. The multi-functionality of UHRF1: epigenome maintenance and preservation of genome integrity [J]. Nucleic Acids Res, 2021, 49(11): 6053-6068.
[118] RHODES D R, YU J, SHANKER K, et al. Large-scale meta-analysis of cancer microarray data identifies common transcriptional profiles of neoplastic transformation and progression [J]. Proc Natl Acad Sci U S A, 2004, 101(25): 9309-9314.
[119] YAMASHITA T, JI J, BUDHU A, et al. EpCAM-positive hepatocellular carcinoma cells are tumor-initiating cells with stem/progenitor cell features [J]. Gastroenterology, 2009, 136(3): 1012-1024.
[120] LIU M, YAN Q, SUN Y, et al. A hepatocyte differentiation model reveals two subtypes of liver cancer with different oncofetal properties and therapeutic targets [J]. Proc Natl Acad Sci U S A, 2020, 117(11): 6103-6113.
[121] BECK D, BEN MAAMAR M, SKINNER M K. Genome-wide CpG density and DNA methylation analysis method (MeDIP, RRBS, and WGBS) comparisons [J]. Epigenetics, 2022, 17(5): 518-530.
[122] JELTSCH A, JURKOWSKA R Z. New concepts in DNA methylation [J]. Trends Biochem Sci, 2014, 39(7): 310-318.
[123] PETRYK N, BULTMANN S, BARTKE T, et al. Staying true to yourself: mechanisms of DNA methylation maintenance in mammals [J]. Nucleic Acids Res, 2021, 49(6): 3020-3032.
[124] JONES P A. Functions of DNA methylation: islands, start sites, gene bodies and beyond [J]. Nature Reviews Genetics, 2012, 13(7): 484-492.
[125] LI J, LI Y, LI W, et al. Guide Positioning Sequencing identifies aberrant DNA methylation patterns that alter cell identity and tumor-immune surveillance networks [J]. Genome Res, 2019, 29(2): 270-280.
[126] HERNANDEZ-MEZA G, VON FELDEN J, GONZALEZ-KOZLOVA E E, et al. DNA Methylation Profiling of Human Hepatocarcinogenesis [J]. Hepatology, 2021, 74(1): 183-199.
[127] FONTANA D, CRESPIATICO I, CRIPPA V, et al. Evolutionary signatures of human cancers revealed via genomic analysis of over 35,000 patients [J]. Nat Commun, 2023, 14(1): 5982.
[128] ZHANG R, DONG Y, XING X. Comprehensive transcriptome analysis of sika deer antler using PacBio and Illumina sequencing [J]. Scientific reports, 2022, 12(1): 16161.
[129] LLOVET J M, PINYOL R, KELLEY R K, et al. Molecular pathogenesis and systemic therapies for hepatocellular carcinoma [J]. Nat Cancer, 2022, 3(4): 386-401.
[130] ANH N H, LONG N P, MIN Y J, et al. Molecular and Metabolic Phenotyping of Hepatocellular Carcinoma for Biomarker Discovery: A Meta-Analysis [J]. Metabolites, 2023, 13(11).
[131] LEE T K, GUAN X Y, MA S. Cancer stem cells in hepatocellular carcinoma - from origin to clinical implications [J]. Nat Rev Gastroenterol Hepatol, 2022, 19(1): 26-44.
[132] DOHENY D, MANORE S G, WONG G L, et al. Hedgehog Signaling and Truncated GLI1 in Cancer [J]. Cells, 2020, 9(9).
[133] LUO J, GONG L, YANG Y, et al. Enhanced mitophagy driven by ADAR1-GLI1 editing supports the self-renewal of cancer stem cells in HCC [J]. Hepatology, 2023.
[134] ZHANG Y, BEACHY P A. Cellular and molecular mechanisms of Hedgehog signalling [J]. Nat Rev Mol Cell Biol, 2023, 24(9): 668-687.
[135] YANG L, SHI P, ZHAO G, et al. Targeting cancer stem cell pathways for cancer therapy [J]. Signal Transduct Target Ther, 2020, 5(1): 8.
[136] ABRAHAM A, MATSUI W. Hedgehog Signaling in Myeloid Malignancies [J]. Cancers (Basel), 2021, 13(19).
[137] YANG F, RODRIGUEZ-BLANCO J, LONG J, et al. A Druggable UHRF1/DNMT1/GLI Complex Regulates Sonic Hedgehog-Dependent Tumor Growth [J]. Mol Cancer Res, 2022, 20(11): 1598-1610.
[138] AKAI Y, OITATE T, KOIKE T, et al. Impaired hepatocyte maturation, abnormal expression of biliary transcription factors and liver fibrosis in C/EBPα(Cebpa)-knockout mice [J]. Histol Histopathol, 2014, 29(1): 107-125.
[139] LOURENçO A R, COFFER P J. A tumor suppressor role for C/EBPα in solid tumors: more than fat and blood [J]. Oncogene, 2017, 36(37): 5221-5230.
[140] TSENG H H, HWANG Y H, YEH K T, et al. Reduced expression of C/EBP alpha protein in hepatocellular carcinoma is associated with advanced tumor stage and shortened patient survival [J]. J Cancer Res Clin Oncol, 2009, 135(2): 241-247.
[141] MACKERT J R, QU P, MIN Y, et al. Dual negative roles of C/EBPα in the expansion and pro-tumor functions of MDSCs [J]. Scientific reports, 2017, 7(1): 14048.
[142] JOHNSON P J, BERHANE S, KAGEBAYASHI C, et al. Assessment of liver function in patients with hepatocellular carcinoma: a new evidence-based approach-the ALBI grade [J]. J Clin Oncol, 2015, 33(6): 550-558.
[143] ZHAO X, VOUTILA J, GHOBRIAL S, et al. Treatment of Liver Cancer by C/EBPA saRNA [J]. Adv Exp Med Biol, 2017, 983: 189-194.
[144] REEBYE V, HUANG K W, LIN V, et al. Gene activation of CEBPA using saRNA: preclinical studies of the first in human saRNA drug candidate for liver cancer [J]. Oncogene, 2018, 37(24): 3216-3228.
[145] YANG X, HAN H, DE CARVALHO D D, et al. Gene body methylation can alter gene expression and is a therapeutic target in cancer [J]. Cancer Cell, 2014, 26(4): 577-590.
[146] YAN Q, ZHANG Y, FANG X, et al. PGC7 promotes tumor oncogenic dedifferentiation through remodeling DNA methylation pattern for key developmental transcription factors [J]. Cell Death Differ, 2021, 28(6): 1955-1970.
[147] SEO J S, CHOI Y H, MOON J W, et al. Hinokitiol induces DNA demethylation via DNMT1 and UHRF1 inhibition in colon cancer cells [J]. BMC Cell Biol, 2017, 18(1): 14.
[148] HUANG A, YANG X R, CHUNG W Y, et al. Targeted therapy for hepatocellular carcinoma [J]. Signal Transduct Target Ther, 2020, 5(1): 146.
[149] PFISTER S X, ASHWORTH A. Marked for death: targeting epigenetic changes in cancer [J]. Nat Rev Drug Discov, 2017, 16(4): 241-263.
[150] LI E, BESTOR T H, JAENISCH R. Targeted mutation of the DNA methyltransferase gene results in embryonic lethality [J]. Cell, 1992, 69(6): 915-926.
[151] KAJI K, FACTOR V M, ANDERSEN J B, et al. DNMT1 Is a Required Genomic Regulator for Murine Liver Histogenesis and Regeneration [J]. Hepatology, 2016, 64(2): 582-598.