EZH2在促进胃癌侵袭和进展中的作用和机制研究
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摘要
胃癌严重危险着人类健康,在我国胃癌的死亡率高居各类癌症死亡的第一位。根据流行病学资料,2008年我国胃癌的发病人数约为463000,同年约325000患者死于胃癌。EZH2(果蝇Zeste基因增强子人类同源物2)是PRC2(多梳抑制复合物2)的核心催化原件,能够通过作用于组蛋白使其甲基化而发挥对靶基因的转录抑制作用。肿瘤病因学的研究显示,诸多上皮来源的恶性肿瘤中,EZH2在促进癌前病变向癌症发生恶性转化的过程中发挥着重要作用。大量报道称,在包括前列腺癌、乳腺癌在内的一些癌症组织中EZH2常常呈高表达状态。此外,越来越多的实验数据表明,EZH2的异常表达与恶性肿瘤的进展相关,EZH2的高表的可能对肿瘤细胞的侵袭能力和扩散能力等生物学特性有促进作用。但是,目前为止EZH2在胃癌的发生发展中所发挥的确切作用还不十分清楚,其促进癌症侵袭和转移的内在分子机制的探究还未见报道。
在本文的实验中,通过应用实时定量RT-PCR,以癌旁正常组织为对照检测了所收集病例胃癌组织中EZH2的相对表达量,采集了病例的临床病理参数和环境因素的暴露情况等资料。应用统计学方法分析了EZH2mRNA的表达水平和临床病理参数之间的关联性,以及环境因素和EZH2mRNA的表达的相互关系。该研究设计并合成了EZH2的小RNA干扰序列,并借助脂质体将其转染到胃癌MKN-45细胞株。利用实时定量RT-PCR、western blot,分别测定了转染前后,胃癌MKN-45细胞株EZH2和E-cadherin的mRNA和蛋白表达水平的变化。利用细胞流式仪、MTT、transwell体外细胞侵袭实验和划痕愈合实验,检测了小RNA干扰沉默胃癌MKN-45细胞株EZH2的表达后,肿瘤细胞的增殖、侵袭和迁移等生物学特性所发生的变化。通过MTT实验检测了转染EZH2si RNA后,胃癌MKN-45细胞株耐药性所发生的改变。
本研究显示,癌组织EZH2mRNA的表达显著高于相应癌旁正常组织,EZH2的高表达和癌组织的浸润深度、淋巴结的转移显著正相关,与癌组织的分化程度呈负相关。胃癌细胞株MKN-45,SGC-7901和MKN-28均表达EZH2基因,MKN-45,SGC-7901中EZH2基因的表达较MKN-28高。吸烟、进食腌菜与EZH2的高表达呈正相关。流式细胞仪和MTT实验显示,干扰EZH2mRNA的表达后,细胞的增殖能力明显受到抑制。划痕愈合实验、transwell体外细胞侵袭实验表明胃癌MKN-45细胞株的迁移能力在转染EZH2si RNA后明显降低。实验还显示了EZH2的表达下调后E-cadherin在mRNA和蛋白水平的表达均会明显上调。
本实验研究表明了EZH2的高表达在胃癌的发生和进展中发挥重要作用,EZH2的表达水平可以用来作为参数指标判定胃癌的恶性程度。EZH2的高表达可能通过下调E-cadherin的表达而促进胃癌细胞的增殖能力和侵袭能力。据此推测EZH2基因能够作为可行的胃癌生物学治疗的靶基因。
Gastric cancer is a serious risk to human health. Gastric cancer has been ranked the leading cause of cancer-related deaths in China. It is estimated that the incidence of gastric cancer was463000in2008, and it kills more than325000patients in the same year according epidemiology data. Enhancer of Zeste2(EZH2) is the catalytic subunit of Polycomb repressive complex2(PRC2), which mediates transcriptional repression through histone methylation. Studies on human tumors show that EZH2play an important role in promoting malignant transformation of precancerous lesions to cancers in various epithelial tissues. EZH2is frequently over-expressed in a wide variety of cancerous tissue types, including prostate and breast. In addition, increasing evidences suggest dysregulated expression of EZH2may be involved in the progression of malignant cancers, and overexpression of EZH2contribute to a more aggressive clinical behavior. However, the precise role EZH2played in gastric cancer progression remains unclear.
In this study, the relative expression level of EZH2mRNA in gastric cancer tissues compared with corresponding adjacent non-tumor gastric tissues was examined by RT-PCR, and its correlation with clinical-pathologic parameters and environmental factors was analyzed. EZH2siRNA were synthesized and transfected into gastric cancer cell line MKN-45with lipofectamine. The change of EZH2and E-cadherin expression after transfection was determined using western blot and RT-PCR. The change of MKN-45cell line biological behavior after transfected with EZH2siRNA was determined by flow cytometry, MTT, as well as transwell and wound healing assays. Meanwhile, using MTT assay drug resistance variation of MKN-45cell after transfection was investigated.
This study shows EZH2mRNA expression in gastric cancer was significantly higher than corresponding adjacent non-tumor gastric tissues, elevated EZH2expression in gastric cancer was associated with increasing depth of invasion of gastric cancer, occuring of lymph node metastasis and poorly differentiated type. EZH2was expressed in all gastric cancer cell lines we examined and its expression was higher in MKN-45, SGC-7901than MKN-28. Significant association between EZH2expression with smoking and intake of pickle was observed. Cell proliferative capacity of MKN-45was signiicantly inhibited after transfected with EZH2siRNA compared to non-transfected controls, and cell migration and invasion were also significantly decreased. The mRNA and protein expression of E-cadherin was significantly enhanced in MKN-45cells after EZH2down-regulation.
This reseach demonstrate that EZH2overexpression is critical for gastric cancer progression. The expression level of EZH2may serve as a parameter to identify high malignant degree gastric cancer. Overexpression of EZH2contributes to cell cycle deregulation and aggressive phenotypes of gastric cancer cells, possibly through altering the expression of E-cadherin. This reseach also suggest that EZH2may be a viable target for therapeutic interventions in aggressive gastric cancer.
在本文的实验中,通过应用实时定量RT-PCR,以癌旁正常组织为对照检测了所收集病例胃癌组织中EZH2的相对表达量,采集了病例的临床病理参数和环境因素的暴露情况等资料。应用统计学方法分析了EZH2mRNA的表达水平和临床病理参数之间的关联性,以及环境因素和EZH2mRNA的表达的相互关系。该研究设计并合成了EZH2的小RNA干扰序列,并借助脂质体将其转染到胃癌MKN-45细胞株。利用实时定量RT-PCR、western blot,分别测定了转染前后,胃癌MKN-45细胞株EZH2和E-cadherin的mRNA和蛋白表达水平的变化。利用细胞流式仪、MTT、transwell体外细胞侵袭实验和划痕愈合实验,检测了小RNA干扰沉默胃癌MKN-45细胞株EZH2的表达后,肿瘤细胞的增殖、侵袭和迁移等生物学特性所发生的变化。通过MTT实验检测了转染EZH2si RNA后,胃癌MKN-45细胞株耐药性所发生的改变。
本研究显示,癌组织EZH2mRNA的表达显著高于相应癌旁正常组织,EZH2的高表达和癌组织的浸润深度、淋巴结的转移显著正相关,与癌组织的分化程度呈负相关。胃癌细胞株MKN-45,SGC-7901和MKN-28均表达EZH2基因,MKN-45,SGC-7901中EZH2基因的表达较MKN-28高。吸烟、进食腌菜与EZH2的高表达呈正相关。流式细胞仪和MTT实验显示,干扰EZH2mRNA的表达后,细胞的增殖能力明显受到抑制。划痕愈合实验、transwell体外细胞侵袭实验表明胃癌MKN-45细胞株的迁移能力在转染EZH2si RNA后明显降低。实验还显示了EZH2的表达下调后E-cadherin在mRNA和蛋白水平的表达均会明显上调。
本实验研究表明了EZH2的高表达在胃癌的发生和进展中发挥重要作用,EZH2的表达水平可以用来作为参数指标判定胃癌的恶性程度。EZH2的高表达可能通过下调E-cadherin的表达而促进胃癌细胞的增殖能力和侵袭能力。据此推测EZH2基因能够作为可行的胃癌生物学治疗的靶基因。
Gastric cancer is a serious risk to human health. Gastric cancer has been ranked the leading cause of cancer-related deaths in China. It is estimated that the incidence of gastric cancer was463000in2008, and it kills more than325000patients in the same year according epidemiology data. Enhancer of Zeste2(EZH2) is the catalytic subunit of Polycomb repressive complex2(PRC2), which mediates transcriptional repression through histone methylation. Studies on human tumors show that EZH2play an important role in promoting malignant transformation of precancerous lesions to cancers in various epithelial tissues. EZH2is frequently over-expressed in a wide variety of cancerous tissue types, including prostate and breast. In addition, increasing evidences suggest dysregulated expression of EZH2may be involved in the progression of malignant cancers, and overexpression of EZH2contribute to a more aggressive clinical behavior. However, the precise role EZH2played in gastric cancer progression remains unclear.
In this study, the relative expression level of EZH2mRNA in gastric cancer tissues compared with corresponding adjacent non-tumor gastric tissues was examined by RT-PCR, and its correlation with clinical-pathologic parameters and environmental factors was analyzed. EZH2siRNA were synthesized and transfected into gastric cancer cell line MKN-45with lipofectamine. The change of EZH2and E-cadherin expression after transfection was determined using western blot and RT-PCR. The change of MKN-45cell line biological behavior after transfected with EZH2siRNA was determined by flow cytometry, MTT, as well as transwell and wound healing assays. Meanwhile, using MTT assay drug resistance variation of MKN-45cell after transfection was investigated.
This study shows EZH2mRNA expression in gastric cancer was significantly higher than corresponding adjacent non-tumor gastric tissues, elevated EZH2expression in gastric cancer was associated with increasing depth of invasion of gastric cancer, occuring of lymph node metastasis and poorly differentiated type. EZH2was expressed in all gastric cancer cell lines we examined and its expression was higher in MKN-45, SGC-7901than MKN-28. Significant association between EZH2expression with smoking and intake of pickle was observed. Cell proliferative capacity of MKN-45was signiicantly inhibited after transfected with EZH2siRNA compared to non-transfected controls, and cell migration and invasion were also significantly decreased. The mRNA and protein expression of E-cadherin was significantly enhanced in MKN-45cells after EZH2down-regulation.
This reseach demonstrate that EZH2overexpression is critical for gastric cancer progression. The expression level of EZH2may serve as a parameter to identify high malignant degree gastric cancer. Overexpression of EZH2contributes to cell cycle deregulation and aggressive phenotypes of gastric cancer cells, possibly through altering the expression of E-cadherin. This reseach also suggest that EZH2may be a viable target for therapeutic interventions in aggressive gastric cancer.
引文
[1]Varambally S, Dhanasekaran SM, Zhou M, et al. The polycomb group protein EZH2 is involved in progression of prostate cancer[J]. Nature.2002,419:624-629.
[2]Kleer CG, Cao Q, Varambally S, et al. EZH2 is a marker of aggressive breast cancer and promotes neoplastic transformation of breast epithelial cells[J]. Proceedings of the National Academy of Sciences.2003,100:11606-11611.
[3]Raman JD, Mongan NP, Tickoo SK, et al. Increased expression of the polycomb group gene, EZH2, in transitional cell carcinoma of the bladder[J]. Clin Cancer.2005,11:8570-8576.
[4]Bachmann IM, Halvorsen OJ, Collett K, et al. EZH2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast[J]. J Clin Oncol.2006,24:268-273.
[5]李清龙,杨乐平,苗雄鹰等.大鼠胰腺癌和非癌胰腺组织中EZH2和PTEN的表达及其意义[J].中国普通外科杂志.2010,19(3)：250-254.
[6]李江,范钦和,樊祥山等.前列腺癌中EZH2 mRNA及蛋白表达与细胞增殖的关系[J].临床与实验病理学杂志.2009,25(6)：615-618.
[7]朱静,张殊,狄文.EZH2组蛋白甲基转移酶在肿瘤发生发展中的作用[J].国际妇产科学杂志.2011,38(5)：415-418.
[8]Hussain M, Rao M, Humphries AE, et al. Tobacco smoke induces polycomb-mediated repression of Dickkopf-1 in lung cancer cells[J]. Cancer Res.2009,69:3570-3578.
[9]Zeidler M, Varambally S, Cao Q, et al. The Polycomb group protein EZH2 impairs DNA repair in breast epithelial cells[J]. Neoplasia.2005,7:1011-1019.
[10]Trivedi M, Davis RA, Shabaik Y, et al. The role of covalent dimerization on the physical and chemical stability of the EC1 domain of human E-cadherin[J]. J Pharm.2009,98:3562-3574.
[11]Trivedi M, Laurence JS, Williams TD, et al. Improving the stability of the EC1 domain of E-cadherin by thiol alkylation of the cysteine residue[J]. Int J Pharm.2012,431:16-25.
[12]古强,王栋,王星辉等.上皮钙粘蛋白基因甲基化与肺癌生物学行为的关系[J].天津医科大学学报.2007,13(1)：10-12.
[13]王红兵,苗慧,张敬川,等.肺癌E-cadherin基因启动子CpG岛甲基化的研究[J].实用癌症杂志.2007,22(4)：357-359.
[14]赵军,黄士勇,于恩达.胃癌组织中E-钙粘蛋白表达与浸润转移的关系[J].肿瘤防治杂志.2003,10(7)：701-703.
[15]陈晓峰,苏晋梅,王海峰等PCR-SSCP法检测E-cadherin基因突变与非小细胞肺癌术后预后及淋巴结转移关系的研究[J].中国肿瘤.2008,17(5)：413-416.
[16]Greenburg G, Hay ED. Epithelia suspended in collagen gels can lose polarity and express characteristics of migrating mesenchymal cells[J]. J Cell Biol.1982,95:333-339.
[17]Sun CK, Ng KT, Lim ZX, et al. Proline-rich tyrosine kinase 2 (Pyk2) promotes cell motility of hepatocellular carcinoma through induction of epithelial to mesenchymal transition[J]. PLoS One.2011,6:e18878.
[18]Nakashima H, Hashimoto N, Aoyama D, et al. Involvement of the transcription factor twist in phenotype alteration through epithelial-mesenchymal transition in lung cancer cells[J]. Mol Carcinog.2012,51:400-410.
[19]Wendt MK, Taylor MA, Schiemann BJ, et al. Down-regulation of epithelial cadherin is required to initiate metastatic outgrowth of breast cancer[J]. Mol Biol Cell.2011, 22:2423-2435.
[20]Yue L, Jiang Z, Wu W, et al. Latent membrane protein-1 of EB virus and the phenotype of epithelial-mesenchymal transition and cervical lymph node metastasis in nasopharyngeal carcinoma[J]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi.2011,25:270-273.
[21]Hirohashi S. Inactivation of the E-cadherin-mediated cell adhesion system in human cancers[J].Am J Pathol.1998,153:333-339.
[22]Boyd JM, Subramanian T, Schaeper U, et al. A region in the C-terminus of adenovirus 2/5 Ela protein is required for association with a cellular phosphoprotein and important for the negative modulation of T24-ras mediated transformation, tumorigenesis and metastasis[J]. EMBOJ.1993,12:469-478.
[23]Kim JH,Park JM,Jung CW, et al. The significances of lymph node micrometastasis and its correlation with E-cadherin expression in pTl-T3N0 gastric denocarcinoma[J]. Journal of Surgical Oncology.2008,97(2):125-130.
[24]罗秉庆,郑绍光,唐青梅E-cadherin和EGFR表达与胃癌浸润转移的关系[J].实用癌症杂志.2004,19(6)：588-591.
[25]Lascombe I,Clairotte A,Fauconnet S, et al.N-cadherin as a novel prognostic marker of progression in superficial urothelial tumors[J]. Clin Cancer Res.2006,12(9):2780-2787.
[26]Cho HJ, Baek KE, Saika S, et al.Snail is required for transforming growth factor-beta-induced epithelial-mesenchymal transition by activating PI3 kinase/Akt signal pathway[J]. Biochem Biophys Res Commun.2007,353(2):337-343.
[27]Marta S, Manel U, Jose M, et al. Evaluation fo two new urinary tumor markers:bladder tumor fibronectin and cytokeratin 18 for the diagnosis of bladder[J]. Clin Cancer Res.2006, (9):3585-3594.
[28]Xie TX, Wet D, Liu M, et al. Star 3 activation regulates the expression of matrix metalloproteinase-2 and tumor invasion and metastasis[J]. Oncogene.2009, 23(20):3550-3560.
[29]Sier CF, Kubben FJ, Ganesh S, et al. Tissue levels of matrix metalloproteinases MMP2 and MMP9 are related to the overall survival of patients with gastric carcinoma[J]. Br J Cancer. 2008,74(3):413-417.
[30]Kirkland SC. Type I collagen inhibits differentiation and promotes a stem cell-like phenotype in human colorectal carcinoma cells[J]. British Journal of Cancer.2009,101:320-326.
[31]徐飚,王建明.胃癌流行病学研究[J].中华肿瘤防治杂志.2006,13(1)：127.
[32]Monig SP, Schroder W, Baldus SE, et al. Preperative lymph node staging in gastrointestinal career-correlation between size and tumor stage[J]. Onkologie.2002,25:342-344.
[33]Kuni saki C, Shimada H, Nomura M, et al. Distribution of lymph node metastasis in gastasis carcinoma[J]. Hepatogastroenterology.2006,53:468-472.
[34]Zou XN, Duan JJ, Huangfu XM, et al. Analysis of stomach cancer mortality in the national retrospective sampling survey of death causes in China,2004-2005[J]. Chinese Journal of Preventive Medicine.2010,44(5):390-397.
[35]Ponder B. Polycyclic aromatic hydrocarbon exposure in oesophageal tissue and risk of oesophageal squamous cell carcinoma in north-eastern Iran[J]. Arch Iran Med.2010, 13(5):457-458.
[36]Wang XQ, Terry PD, Yan H. Review of salt consumption and stomach cancer risk: epidemiological and biological evidence[J]. World J Gastroenterol.2009,15 (18):2204-2213.
[37]林国辉,张思宇,李良庆等.EZH2基因在胃癌中的表达及意义[J].广东医学.2011,32(24)：3233-3235.
[38]焦付丰,曲维兰,王长印等.胃癌患者血清细胞因子水平变化及与肿瘤分化程度的关系[J].山东医药.2011,51(43)：26-27.
[37]Mussunoor S, Murray GI. The role of annexins in tumour development and p rogression[J]. J Pathol.2008,216 (2):131-140.
[38]Kim JW, Hwang I, Kim MJ, et al. Clinicopathological characteristics and predictive markers of early gastric cancer with recurrence[J]. J Korean Med.2009,24(6):1158-1164.
[39]Shin H, Kim I, Lee E, et al. Molecular Analysis of IDH2, DNMT3A, EZH2, WT1 and CBL Mutations in Acute Myeloid Leukemia Patients with t(8;21)(q22;q22)[J].JOURNAL OF MOLECULAR DIAGNOSTICS.2012,12(6):664-665.
[40]徐瑞权microRNA-101和EZH2基因在前列腺癌干细胞中的表达研究[D].江西：南昌大学.2011.
[41]Mimori K, Ogawa K, Okamoto M, et al. Clinical significance of enhancer of zeste homolog 2 expression in colorectal cancer cases[J]. EJSO.2005,31(4):376-380.
[42]Sudo T, Utsunomiya T, Mimori K, et al. Clinicopathological significance of EZH2 mRNA expression in patients with hepatocellular carcinoma[J]. BRITISH JOURNAL OF CANCER. 2005,92(9):1754-1758.
[43]Arisan, S, Buyuktuncer, ED, Palavan-Unsal N, et al. Increased expression of EZH2, a polycomb group protein, in bladder carcinoma[J]. UROLOGIA INTERNATIONALIS.2005, 75(3):252-257.
[44]Ohata H, Kitauchi S, Yoshimura N, et al. Progression of chronic atrophic gastritis associated with Helicobacter pylori infection increases risk of gastric cancer[J]. International Journal of Cancer.2004,109:138.
[45]Ozer I, Bostanci EB, Orug T, et al. Surgical outcomes and survival after multiorgan resection for locally advanced gastric cancer[J]. Am J Surg.2009,198(1):25-30.
[46]邹晶,高磊,李晋等.针对不同特征基因挖掘方法的特征基因功能一致性分析[J].中国生物医学工程学报.2010,29(2)：212-219.
[47]Peto R, Darby S, Deo H, et al. Smoking, smoking cessation, and lung cancer in the UK since 1950:combination of national statistics with two case-control studies[J]. British Medical Journal.2000,321:323-329.
[48]Fujino Y, Mizoue T, Tokui N, et al. Cigarette smoking and mortality due to stomach cancer.findings from the JACC Study[J]. J Epidemiol.2005,15(2):113-119.
[49]Ward MH, Rusiecki JA, Lynch CF, et al. Nit rate in public water supplies and the risk of renal cell arcinoma[J]. Cancer Causes Control.2007,18 (10):1141-1151.
[50]Brody J G, Aschengrau A, McKelvey W, et al. Breast cancer risk and drinking water contaminated by waste water:a case cont rol study[J]. Environ Health.2006,5(10):28-39.
[51]Koeda K, Nishizuka S, Wakabayashi G. Minimally invasive surgery for gastric cancer:the future standard of care[J]. World J Surg.2011,35(7):1469-1477.
[52]Ichikawa D, Komatsu S, Okamoto K, et al. Esophagogastrostomy using a circular stapler in laparoscopy assisted proximal gastrectomy with an incision in the left abdomen[J]. Langenbecks Arch Surg.2012,397(1):57-62.
[53]Jiang X, Hiki N, Nunobe S, et al. Long-term outcome and survival with laparoscopy-assisted pylorus-preserving gastrectomy for early gastric cancer[J]. Surg Endosc.2011,25(4): 1182-1186.
[54]Liotta LA, Wewer U, Rao NC, et al. Biochemical mechanisms of tumor invasion and metastasis[J]. Anticancer Drug Des.1987,2:195-202.
[55]赵晖,王树成.RNA干扰沉默食管癌COX-2基因的实验研究[J].山东大学学报：医学版.2006,44(3)：256-259.
[56]杨健,胡为民,任碧轩等.RNA干扰体外抑制HBeAg的表达[J].细胞与分子免疫学杂志.2006,22(5)：670-671,673.
[57]Hendruschk S, Wiedemuth R, Aigner A, et al. RNA interference targeting survivin exerts antitumoral effects in vitro and in established glioma xenografts in vivo[J]. Neuro-Oncology. 2011,13(10):1074-1089.
[58]Yang J, Mani SA, Donaher JL, et al. Twist, a master regulator of morphogenesis, plays an essential role in tumor metastasis[J]. Cell.2004,117:927-939.
[59]张凌志,邸菁,王运杰等Transwell小室筛选高侵袭性C6细胞MMP-2和TIMP-2的表达[J].肿瘤防治杂志.2005,12(10)：742-745.
[60]Yang B, Cao JL, Zhang A, et al. Construction of tissue-engineered cartilage by seeding chondrocytes on allogeneic cancellous bone matrix gelatin[J]. Nan Fang Yi Ke Da Xue Xue Bao.2009,29(11):2161-2164.
[61]ZENT CS. The role of alemtuzumab in the treatment of chronic lymphocytic leukemia[J]. Leuk Lymphoma. 2008,49 (2):175-176.
[62]DE JONGE MJ, VERWEIJ J. Multiple targeted tyroine kinase inhibition in the clinic:all for one or one for all?[J]. Eur Jcancer.2006,42(10):1351-1356.
[63]曹相玫,王映梅,谷雨等.EZH2在原发性肝癌中的表达及与分化和增殖的关系[J].现代肿瘤医学.2013,21(3)：453-456.
[64]陆海霞,危丹明,冯震博.EZH2在肝细胞癌中的表达及临床意义[J].解剖学报.2011,42(1)：75-79.
[65]Sasaki M, Ikeda H, Itatsu K, et al. The overexpression of polycomb group proteins Bmil and EZH2 is associated with the progression and aggressive biological behavior of hepatocellular carcinoma[J]. Lab Invest. 2008,88(8):873-882.
[66]林远洪,雷小林,吴永等.靶向FGFR基因shRNA抑制胰腺癌PANC-1细胞增殖的研究[J].肿瘤防治研究.2011,38(9)：2012-1015.
[67]Bryant RJ, Winder SJ, Cross SS, et al. The Polycomb Group protein EZH2 regulates actin polymerization in human prostate cancer cells[J]. Prostate.2008,68:255-263.
[68]玄东春,崔演,张凤艳等.胃癌组织中EZH2和p53蛋白的表达及临床意义[J].临床与实验病理学杂志.2011,27(11)：1161-1164.
[69]Bracken AP, Pasini D, Capra M, et al. EZH2 is downstream of the pRB-E2F pathway, essential for proliferation and amplified in cancer[J]. EMBO J.2003,22:5323-5335.
[70]Aoki R, Chiba T, Miyagi S, Neqishi M, Konuma T, et al. The polycomb group gene product Ezh2 regulates proliferation and differentiation of murine hepatic stem/progenitor cells[J]. J Hepatol.2010,52:854-863.
[71]Luo TH, Fang GE, Bi JW, et al. The effect of perineural invasion on overall survival in patients with gastric carcinoma [J]. Gastrointest Sur.2008,12(7):1263-1267.
[72]Bachmann IM, H alvorsen OJ, Co llettK, et al. EZH 2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast[J]. J Clin Oncol.2006,24(2):268-273.
[73]Varambally S, Cao Q, Mani RS, et al. Genomic loss of microRNA-101 leads to overexpression of histone methyltransferase EZH2 in cancer[J]. Science.2008, 322:1695-1699.
[1]Jones PA, Baylin SB. The fundamental role of epigenetic events in cancer[J]. Nat Rev Genet. 2002,3:415-428.
[2]Laird PW. The power and the promise of DNA methylation markers[J]. Nat Rev Cancer.2003, 3:253-266.
[3]Ting AH, McGarvey KM, Baylin SB. The cancer epigenome--components and functional correlates[J]. Genes Dev.2006,20:3215-3231.
[4]Sparmann A, van Lohuizen M. Polycomb silencers control cell fate, development and cancer[J]. Nat Rev Cancer.2006,6:846-856.
[5]Fraga MF, Ballestar E, Villar-Garea A, et al. Loss of acetylation at Lys16 and trimethylation at Lys20 of histone H4 is a common hallmark of human cancer[J]. Nat Genet.2005, 37:391-400.
[6]Seligson DB, Horvath S, Shi T, et al. Global histone modification patterns predict risk of prostate cancer recurrence[J]. Nature.2005,435:1262-1266.
[7]Feinberg AP, Ohlsson R, Henikoff S. The epigenetic progenitor origin of human cancer[J]. Nat Rev Genet.2006,7:21-33.
[8]Chen H, Rossier C, Antonarakis SE. Cloning of a human homolog of the Drosophila enhancer of zeste gene (EZH2) that maps to chromosome 21q22.2[J]. Genomics.1996,38:30-37.
[9]Cardoso C, Mignon C, Hetet G, et al. The human EZH2 gene:genomic organisation and revised mapping in 7q35 within the critical region for malignant myeloid disorders[J]. Eur J Hum Genet.2000,8:174-180.
[10]Cardoso C, Timsit S, Villard L,et al. Specific interaction between the XNP/ATR-X gene product and the SET domain of the human EZH2 protein[J]. Hum Mol Genet.1998, 7:679-684.
[11]Qian C, Zhou MM. SET domain protein lysine methyltransferases:Structure, specificity and catalysis[J]. Cell Mol Life.2006,63:2755-2763.
[12]Aravind L, Iyer LM. Provenance of SET-domain histone methyltransferases through duplication of a simple structural unit[J]. Cell Cycle.2003,2:369-376.
[13]Cao R, Zhang Y. The functions of E(Z)/EZH2-mediated methylation of lysine 27 in histone H3[J]. Curr Opin Genet Dev.2004,14:155-164.
[14]Cao R, Wang L, Wang H, et al. Role of histone H3 lysine 27 methylation in Polycomb-group silencing[J]. Science.2002,298:1039-1043.
[15]Rea S, Eisenhaber F, O'Carroll D, et al. Regulation of chromatin structure by site-specific histone H3 methyltransferases[J]. Nature.2000,406:593-599.
[16]Montgomery ND, Yee D, Chen A, et al. The murine polycomb group protein Eed is required for global histone H3 lysine-27 methylation[J]. Curr Biol.2005,15:942-947.
[17]Ketel CS, Andersen EF, Vargas ML, et al. Subunit contributions to histone methyltransferase activities of fly and worm polycomb group complexes[J]. Mol Cell Biol.2005, 25:6857-6868.
[18]Nekrasov M, Klymenko T, Fraterman S, et al. Pcl-PRC2 is needed to generate high levels of H3-K27 trimethylation at Polycomb target genes[J]. EMBO J.2007,26:4078-4088.
[19]Vire E, Brenner C, Deplus R,et al. The Polycomb group protein EZH2 directly controls DNA methylation[J]. Nature.2006,439:871-874.
[20]McGarvey KM, Greene E, Fahrner JA, et al. DNA methylation and complete transcriptional silencing of cancer genes persist after depletion of EZH2[J]. Cancer Res.2007, 67:5097-5102.
[21]Ohm JE, McGarvey KM, Yu X, et al. A stem cell-like chromatin pattern may predispose tumor suppressor genes to DNA hypermethylation and heritable silencing[J]. Nat Genet. 2007,39:237-242.
[22]Schlesinger Y, Straussman R, Keshet I, et al. Polycomb-mediated methylation on Lys27 of histone H3 pre-marks genes for de novo methylation in cancer[J]. Nat Genet.2007, 39:232-236.
[23]Widschwendter M, Fiegl H, Egle D, et al. Epigenetic stem cell signature in cancer[J]. Nat Genet.2007,39:157-158.
[24]Kirmizis A, Bartley SM, Kuzmichev A, et al. Silencing of human polycomb target genes is associated with methylation of histone H3 Lys 27[J]. Genes Dev.2004,18:1592-1605.
[25]Villa R, Pasini D, Gutierrez A, et al. Role of the polycomb repressive complex 2 in acute promyelocytic leukemia[J]. Cancer Cell.2007,11:513-525.
[26]Tie F, Furuyama T, Prasad-Sinha J, et al. The Drosophila Polycomb Group proteins ESC and E(Z) are present in a complex containing the histone-binding protein p55 and the histone deacetylase RPD3[J]. Development.2001,128:275-286.
[27]Varambally S, Dhanasekaran SM, Zhou M, et al. The polycomb group protein EZH2 is involved in progression of prostate cancer[J]. Nature.2002,419:624-629.
[28]Bracken AP, Pasini D, Capra M, et al. EZH2 is downstream of the pRB-E2F pathway, essential for proliferation and amplified in cancer[J]. EMBO J.2003,22:5323-5335.
[29]Rhodes DR, Sanda MG, Otte AP, et al. Multiplex biomarker approach for determining risk of prostate-specific antigen-defined recurrence of prostate cancer[J]. J Natl Cancer Inst.2003, 95:661-668.
[30]Saramaki OR, Tammela TL, Martikainen PM, et al. The gene for polycomb group protein enhancer of zeste homolog 2 (EZH2) is amplified in late-stage prostate cancer[J]. Genes Chromosomes Cancer.2006,45:639-645.
[31]Collett K, Eide GE, Arnes J, et al. Expression of enhancer of zeste homologue 2 is significantly associated with increased tumor cell proliferation and is a marker of aggressive breast cancer[J]. Clin Cancer Res.2006,12:1168-1174.
[32]Bachmann IM, Halvorsen OJ, Collett K, et al. EZH2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast[J]. J Clin Oncol.2006,24:268-273.
[33]Kleer CG, Cao Q, Varambally S, et al. EZH2 is a marker of aggressive breast cancer and promotes neoplastic transformation of breast epithelial cells[J]. Proc Natl Acad.2003, 100:11606-11611.
[34]Ding L, Erdmann C, Chinnaiyan AM, et al. Identification of EZH2 as a molecular marker for a precancerous state in morphologically normal breast tissues[J]. Cancer Res.2006, 66:4095-4099.
[35]Cha TL, Zhou BP, Xia W, et al. Akt-mediated phosphorylation of EZH2 suppresses methylation of lysine 27 in histone H3[J]. Science.2005,310:306-310.
[36]Li X, Gonzalez ME, Toy K,et al. Targeted overexpression of EZH2 in the mammary gland disrupts ductal morphogenesis and causes epithelial hyperplasia[J]. Am J Pathol. 2009, 175:1246-1254.
[37]Endoh M, Endo TA, Endoh T, et al. Polycomb group proteins RinglA/B are functionally linked to the core transcriptional regulatory circuitry to maintain ES cell identity [J]. Development.2008,135:1513-1524.
[38]Rinn JL, Kertesz M, Wang JK, et al. Functional demarcation of active and silent chromatin domains in human HOX loci by noncoding RNAs[J]. Cell.2007,129:1311-1323.
[39]Schwartz YB, Pirrotta V. Polycomb silencing mechanisms and the management of genomic programmes[J]. Nat Rev Genet.2007,8:9-22.
[40]Boyer LA, Plath K, Zeitlinger J, et al. Polycomb complexes repress developmental regulators in murine embryonic stem cells[J]. Nature.2006,441:349-353.
[41]Bracken AP, Dietrich N, Pasini D, et al. Genome-wide mapping of Polycomb target genes unravels their roles in cell fate transitions[J]. Genes Dev.2006,20:1123-1136.
[42]Levine SS, Weiss A, Erdjument-Bromage H, et al. The core of the polycomb repressive complex is compositionally and functionally conserved in flies and humans[J]. Mol Cell Biol. 2002,22:6070-6078.
[43]Fischle W, Wang Y, Jacobs SA, et al. Molecular basis for the discrimination of repressive methyl-lysine marks in histone H3 by Polycomb and HP1 chromodomains[J]. Genes Dev. 2003,17:1870-1881.
[44]Francis NJ, Kingston RE, Woodcock CL. Chromatin compaction by a polycomb group protein complex[J]. Science.2004,306:1574-1577.
[45]Cao R, Tsukada Y, Zhang Y. Role of Bmi-1 and RinglA in H2A ubiquitylation and Hox gene siIencing[J]. Mol Cell,2005,20:845-854.
[46]Zeitlinger J, Stark A, Kellis M, et al. RNA polymerase stalling at developmental control genes in the Drosophila melanogaster embryo[J]. Nat Genet.2007,39:1512-1516.
[47]Guenther MG, Levine SS, Boyer LA, et al. A chromatin landmark and transcription initiation at most promoters in human cells[J]. Cell.2007,130:77-88.
[48]Stock JK, Giadrossi S, Casanova M, et al. Ringl-mediated ubiquitination of H2A restrains poised RNA polymerase II at bivalent genes in mouse ES cells[J]. Nat Cell Biol.2007, 9:1428-1435.
[49]Su IH, Dobenecker MW, Dickinson E, et al. Polycomb group protein ezh2 controls actin polymerization and cell signaling[J]. Cell.2005,121:425-436.
[50]Bryant RJ, Winder SJ, Cross SS, et al. The Polycomb Group protein EZH2 regulates actin polymerization in human prostate cancer cells[J]. Prostate.2008,68:255-263.
[51]Bryant RJ, Cross NA, Eaton CL, et al. EZH2 promotes proliferation and invasiveness of prostate cancer cells[J]. Prostate.2007,67:547-556.
[52]Tolhuis B, de Wit E, Muijrers I, et al. Genome-wide profiling of PRC1 and PRC2 Polycomb chromatin binding in Drosophila melanogaster[J]. Nat Genet.2006,38:694-699.
[53]Negre N, Hennetin J, Sun LV, et al. Chromosomal distribution of PcG proteins during Drosophila development J]. PLoS Biol.2006,4:e170.
[54]Richter GH, Plehm S, Fasan A, et al. EZH2 is a mediator of EWS/FLI1 driven tumor growth and metastasis blocking endothelial and neuro-ectodermal differentiation[J]. Proc Natl Acad.2009,106:5324-5329.
[55]Chang CJ, Yang JY, Xia W, et al. EZH2 promotes expansion of breast tumor initiating cells through activation of RAFl-beta-catenin signaling[J]. Cancer Cell.2011,19:86-100.
[56]Chen S, Bohrer LR, Rai AN, et al. Cyclin-dependent kinases regulate epigenetic gene silencing through phosphorylation of EZH2[J]. Nat Cell Biol.2010,12:1108-1114.
[57]Wei Y, Chen YH, Li LY, et al. CDK1-dependent phosphorylation of EZH2 suppresses methylation of H3K27 and promotes osteogenic differentiation of human mesenchymal stem cells[J]. Nat Cell Biol.2011,13:87-94.
[58]Cao Q, Yu J, Dhanasekaran SM, et al. Repression of E-cadherin by the polycomb group protein EZH2 in cancer[J]. Oncogene.2008,27:7274-7284.
[59]Min J, Zaslavsky A, Fedele G, et al. An oncogene-tumor suppressor cascade drives metastatic prostate cancer by coordinately activating Ras and nuclear factor-kappaB[J]. Nat Med.2010, 16:286-294.
[60]Yu J, Cao Q, Mehra R, et al. Integrative genomics analysis reveals silencing of beta-adrenergic signaling by polycomb in prostate cancer[J]. Cancer Cell.2007,12:419-431.
[61]Lu C, Han HD, Mangala LS, et al. Regulation of tumor angiogenesis by EZH2[J]. Cancer Cell.2010,18:185-197.
[62]Schwartz YB, Kahn TG, Nix DA, et al. Genome-wide analysis of Polycomb targets in Drosophila melanogaster[J]. Nat Genet.2006,38:700-705.
[63]Piunti A, Pasini D. Epigenetic factors in cancer development:polycomb group proteins[J]. Future Oncol.2011,7:57-75.
[64]Visvader JE, Lindeman GJ. Cancer stem cells in solid tumours:accumulating evidence and unresolved questions[J]. Nat Rev Cancer.2008,8:755-768.
[65]Bernstein BE, Mikkelsen TS, Xie X, et al. A bivalent chromatin structure marks key developmental genes in embryonic stem cells[J]. Cell.2006,125:315-326.
[66]Jepsen K, Solum D, Zhou T, et al. SMRT-mediated repression of an H3K27 demethylase in progression from neural stem cell to neuron[J]. Nature.2007,450:415-419.
[67]Agger K, Cloos PA, Christensen J, et al. UTX and JMJD3 are histone H3K27 demethylases involved in HOX gene regulation and development[J]. Nature.2007,449:731-734.
[68]Lobo NA, Shimono Y, Qian D, et al. The biology of cancer stem cells[J]. Annu Rev Cell Dev Biol.2007,23:675-699.
[69]Stingl J, Caldas C. Molecular heterogeneity of breast carcinomas and the cancer stem cell hypothesis[J]. Nat Rev Cancer.2007,7:791-799.
[2]Kleer CG, Cao Q, Varambally S, et al. EZH2 is a marker of aggressive breast cancer and promotes neoplastic transformation of breast epithelial cells[J]. Proceedings of the National Academy of Sciences.2003,100:11606-11611.
[3]Raman JD, Mongan NP, Tickoo SK, et al. Increased expression of the polycomb group gene, EZH2, in transitional cell carcinoma of the bladder[J]. Clin Cancer.2005,11:8570-8576.
[4]Bachmann IM, Halvorsen OJ, Collett K, et al. EZH2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast[J]. J Clin Oncol.2006,24:268-273.
[5]李清龙,杨乐平,苗雄鹰等.大鼠胰腺癌和非癌胰腺组织中EZH2和PTEN的表达及其意义[J].中国普通外科杂志.2010,19(3)：250-254.
[6]李江,范钦和,樊祥山等.前列腺癌中EZH2 mRNA及蛋白表达与细胞增殖的关系[J].临床与实验病理学杂志.2009,25(6)：615-618.
[7]朱静,张殊,狄文.EZH2组蛋白甲基转移酶在肿瘤发生发展中的作用[J].国际妇产科学杂志.2011,38(5)：415-418.
[8]Hussain M, Rao M, Humphries AE, et al. Tobacco smoke induces polycomb-mediated repression of Dickkopf-1 in lung cancer cells[J]. Cancer Res.2009,69:3570-3578.
[9]Zeidler M, Varambally S, Cao Q, et al. The Polycomb group protein EZH2 impairs DNA repair in breast epithelial cells[J]. Neoplasia.2005,7:1011-1019.
[10]Trivedi M, Davis RA, Shabaik Y, et al. The role of covalent dimerization on the physical and chemical stability of the EC1 domain of human E-cadherin[J]. J Pharm.2009,98:3562-3574.
[11]Trivedi M, Laurence JS, Williams TD, et al. Improving the stability of the EC1 domain of E-cadherin by thiol alkylation of the cysteine residue[J]. Int J Pharm.2012,431:16-25.
[12]古强,王栋,王星辉等.上皮钙粘蛋白基因甲基化与肺癌生物学行为的关系[J].天津医科大学学报.2007,13(1)：10-12.
[13]王红兵,苗慧,张敬川,等.肺癌E-cadherin基因启动子CpG岛甲基化的研究[J].实用癌症杂志.2007,22(4)：357-359.
[14]赵军,黄士勇,于恩达.胃癌组织中E-钙粘蛋白表达与浸润转移的关系[J].肿瘤防治杂志.2003,10(7)：701-703.
[15]陈晓峰,苏晋梅,王海峰等PCR-SSCP法检测E-cadherin基因突变与非小细胞肺癌术后预后及淋巴结转移关系的研究[J].中国肿瘤.2008,17(5)：413-416.
[16]Greenburg G, Hay ED. Epithelia suspended in collagen gels can lose polarity and express characteristics of migrating mesenchymal cells[J]. J Cell Biol.1982,95:333-339.
[17]Sun CK, Ng KT, Lim ZX, et al. Proline-rich tyrosine kinase 2 (Pyk2) promotes cell motility of hepatocellular carcinoma through induction of epithelial to mesenchymal transition[J]. PLoS One.2011,6:e18878.
[18]Nakashima H, Hashimoto N, Aoyama D, et al. Involvement of the transcription factor twist in phenotype alteration through epithelial-mesenchymal transition in lung cancer cells[J]. Mol Carcinog.2012,51:400-410.
[19]Wendt MK, Taylor MA, Schiemann BJ, et al. Down-regulation of epithelial cadherin is required to initiate metastatic outgrowth of breast cancer[J]. Mol Biol Cell.2011, 22:2423-2435.
[20]Yue L, Jiang Z, Wu W, et al. Latent membrane protein-1 of EB virus and the phenotype of epithelial-mesenchymal transition and cervical lymph node metastasis in nasopharyngeal carcinoma[J]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi.2011,25:270-273.
[21]Hirohashi S. Inactivation of the E-cadherin-mediated cell adhesion system in human cancers[J].Am J Pathol.1998,153:333-339.
[22]Boyd JM, Subramanian T, Schaeper U, et al. A region in the C-terminus of adenovirus 2/5 Ela protein is required for association with a cellular phosphoprotein and important for the negative modulation of T24-ras mediated transformation, tumorigenesis and metastasis[J]. EMBOJ.1993,12:469-478.
[23]Kim JH,Park JM,Jung CW, et al. The significances of lymph node micrometastasis and its correlation with E-cadherin expression in pTl-T3N0 gastric denocarcinoma[J]. Journal of Surgical Oncology.2008,97(2):125-130.
[24]罗秉庆,郑绍光,唐青梅E-cadherin和EGFR表达与胃癌浸润转移的关系[J].实用癌症杂志.2004,19(6)：588-591.
[25]Lascombe I,Clairotte A,Fauconnet S, et al.N-cadherin as a novel prognostic marker of progression in superficial urothelial tumors[J]. Clin Cancer Res.2006,12(9):2780-2787.
[26]Cho HJ, Baek KE, Saika S, et al.Snail is required for transforming growth factor-beta-induced epithelial-mesenchymal transition by activating PI3 kinase/Akt signal pathway[J]. Biochem Biophys Res Commun.2007,353(2):337-343.
[27]Marta S, Manel U, Jose M, et al. Evaluation fo two new urinary tumor markers:bladder tumor fibronectin and cytokeratin 18 for the diagnosis of bladder[J]. Clin Cancer Res.2006, (9):3585-3594.
[28]Xie TX, Wet D, Liu M, et al. Star 3 activation regulates the expression of matrix metalloproteinase-2 and tumor invasion and metastasis[J]. Oncogene.2009, 23(20):3550-3560.
[29]Sier CF, Kubben FJ, Ganesh S, et al. Tissue levels of matrix metalloproteinases MMP2 and MMP9 are related to the overall survival of patients with gastric carcinoma[J]. Br J Cancer. 2008,74(3):413-417.
[30]Kirkland SC. Type I collagen inhibits differentiation and promotes a stem cell-like phenotype in human colorectal carcinoma cells[J]. British Journal of Cancer.2009,101:320-326.
[31]徐飚,王建明.胃癌流行病学研究[J].中华肿瘤防治杂志.2006,13(1)：127.
[32]Monig SP, Schroder W, Baldus SE, et al. Preperative lymph node staging in gastrointestinal career-correlation between size and tumor stage[J]. Onkologie.2002,25:342-344.
[33]Kuni saki C, Shimada H, Nomura M, et al. Distribution of lymph node metastasis in gastasis carcinoma[J]. Hepatogastroenterology.2006,53:468-472.
[34]Zou XN, Duan JJ, Huangfu XM, et al. Analysis of stomach cancer mortality in the national retrospective sampling survey of death causes in China,2004-2005[J]. Chinese Journal of Preventive Medicine.2010,44(5):390-397.
[35]Ponder B. Polycyclic aromatic hydrocarbon exposure in oesophageal tissue and risk of oesophageal squamous cell carcinoma in north-eastern Iran[J]. Arch Iran Med.2010, 13(5):457-458.
[36]Wang XQ, Terry PD, Yan H. Review of salt consumption and stomach cancer risk: epidemiological and biological evidence[J]. World J Gastroenterol.2009,15 (18):2204-2213.
[37]林国辉,张思宇,李良庆等.EZH2基因在胃癌中的表达及意义[J].广东医学.2011,32(24)：3233-3235.
[38]焦付丰,曲维兰,王长印等.胃癌患者血清细胞因子水平变化及与肿瘤分化程度的关系[J].山东医药.2011,51(43)：26-27.
[37]Mussunoor S, Murray GI. The role of annexins in tumour development and p rogression[J]. J Pathol.2008,216 (2):131-140.
[38]Kim JW, Hwang I, Kim MJ, et al. Clinicopathological characteristics and predictive markers of early gastric cancer with recurrence[J]. J Korean Med.2009,24(6):1158-1164.
[39]Shin H, Kim I, Lee E, et al. Molecular Analysis of IDH2, DNMT3A, EZH2, WT1 and CBL Mutations in Acute Myeloid Leukemia Patients with t(8;21)(q22;q22)[J].JOURNAL OF MOLECULAR DIAGNOSTICS.2012,12(6):664-665.
[40]徐瑞权microRNA-101和EZH2基因在前列腺癌干细胞中的表达研究[D].江西：南昌大学.2011.
[41]Mimori K, Ogawa K, Okamoto M, et al. Clinical significance of enhancer of zeste homolog 2 expression in colorectal cancer cases[J]. EJSO.2005,31(4):376-380.
[42]Sudo T, Utsunomiya T, Mimori K, et al. Clinicopathological significance of EZH2 mRNA expression in patients with hepatocellular carcinoma[J]. BRITISH JOURNAL OF CANCER. 2005,92(9):1754-1758.
[43]Arisan, S, Buyuktuncer, ED, Palavan-Unsal N, et al. Increased expression of EZH2, a polycomb group protein, in bladder carcinoma[J]. UROLOGIA INTERNATIONALIS.2005, 75(3):252-257.
[44]Ohata H, Kitauchi S, Yoshimura N, et al. Progression of chronic atrophic gastritis associated with Helicobacter pylori infection increases risk of gastric cancer[J]. International Journal of Cancer.2004,109:138.
[45]Ozer I, Bostanci EB, Orug T, et al. Surgical outcomes and survival after multiorgan resection for locally advanced gastric cancer[J]. Am J Surg.2009,198(1):25-30.
[46]邹晶,高磊,李晋等.针对不同特征基因挖掘方法的特征基因功能一致性分析[J].中国生物医学工程学报.2010,29(2)：212-219.
[47]Peto R, Darby S, Deo H, et al. Smoking, smoking cessation, and lung cancer in the UK since 1950:combination of national statistics with two case-control studies[J]. British Medical Journal.2000,321:323-329.
[48]Fujino Y, Mizoue T, Tokui N, et al. Cigarette smoking and mortality due to stomach cancer.findings from the JACC Study[J]. J Epidemiol.2005,15(2):113-119.
[49]Ward MH, Rusiecki JA, Lynch CF, et al. Nit rate in public water supplies and the risk of renal cell arcinoma[J]. Cancer Causes Control.2007,18 (10):1141-1151.
[50]Brody J G, Aschengrau A, McKelvey W, et al. Breast cancer risk and drinking water contaminated by waste water:a case cont rol study[J]. Environ Health.2006,5(10):28-39.
[51]Koeda K, Nishizuka S, Wakabayashi G. Minimally invasive surgery for gastric cancer:the future standard of care[J]. World J Surg.2011,35(7):1469-1477.
[52]Ichikawa D, Komatsu S, Okamoto K, et al. Esophagogastrostomy using a circular stapler in laparoscopy assisted proximal gastrectomy with an incision in the left abdomen[J]. Langenbecks Arch Surg.2012,397(1):57-62.
[53]Jiang X, Hiki N, Nunobe S, et al. Long-term outcome and survival with laparoscopy-assisted pylorus-preserving gastrectomy for early gastric cancer[J]. Surg Endosc.2011,25(4): 1182-1186.
[54]Liotta LA, Wewer U, Rao NC, et al. Biochemical mechanisms of tumor invasion and metastasis[J]. Anticancer Drug Des.1987,2:195-202.
[55]赵晖,王树成.RNA干扰沉默食管癌COX-2基因的实验研究[J].山东大学学报：医学版.2006,44(3)：256-259.
[56]杨健,胡为民,任碧轩等.RNA干扰体外抑制HBeAg的表达[J].细胞与分子免疫学杂志.2006,22(5)：670-671,673.
[57]Hendruschk S, Wiedemuth R, Aigner A, et al. RNA interference targeting survivin exerts antitumoral effects in vitro and in established glioma xenografts in vivo[J]. Neuro-Oncology. 2011,13(10):1074-1089.
[58]Yang J, Mani SA, Donaher JL, et al. Twist, a master regulator of morphogenesis, plays an essential role in tumor metastasis[J]. Cell.2004,117:927-939.
[59]张凌志,邸菁,王运杰等Transwell小室筛选高侵袭性C6细胞MMP-2和TIMP-2的表达[J].肿瘤防治杂志.2005,12(10)：742-745.
[60]Yang B, Cao JL, Zhang A, et al. Construction of tissue-engineered cartilage by seeding chondrocytes on allogeneic cancellous bone matrix gelatin[J]. Nan Fang Yi Ke Da Xue Xue Bao.2009,29(11):2161-2164.
[61]ZENT CS. The role of alemtuzumab in the treatment of chronic lymphocytic leukemia[J]. Leuk Lymphoma. 2008,49 (2):175-176.
[62]DE JONGE MJ, VERWEIJ J. Multiple targeted tyroine kinase inhibition in the clinic:all for one or one for all?[J]. Eur Jcancer.2006,42(10):1351-1356.
[63]曹相玫,王映梅,谷雨等.EZH2在原发性肝癌中的表达及与分化和增殖的关系[J].现代肿瘤医学.2013,21(3)：453-456.
[64]陆海霞,危丹明,冯震博.EZH2在肝细胞癌中的表达及临床意义[J].解剖学报.2011,42(1)：75-79.
[65]Sasaki M, Ikeda H, Itatsu K, et al. The overexpression of polycomb group proteins Bmil and EZH2 is associated with the progression and aggressive biological behavior of hepatocellular carcinoma[J]. Lab Invest. 2008,88(8):873-882.
[66]林远洪,雷小林,吴永等.靶向FGFR基因shRNA抑制胰腺癌PANC-1细胞增殖的研究[J].肿瘤防治研究.2011,38(9)：2012-1015.
[67]Bryant RJ, Winder SJ, Cross SS, et al. The Polycomb Group protein EZH2 regulates actin polymerization in human prostate cancer cells[J]. Prostate.2008,68:255-263.
[68]玄东春,崔演,张凤艳等.胃癌组织中EZH2和p53蛋白的表达及临床意义[J].临床与实验病理学杂志.2011,27(11)：1161-1164.
[69]Bracken AP, Pasini D, Capra M, et al. EZH2 is downstream of the pRB-E2F pathway, essential for proliferation and amplified in cancer[J]. EMBO J.2003,22:5323-5335.
[70]Aoki R, Chiba T, Miyagi S, Neqishi M, Konuma T, et al. The polycomb group gene product Ezh2 regulates proliferation and differentiation of murine hepatic stem/progenitor cells[J]. J Hepatol.2010,52:854-863.
[71]Luo TH, Fang GE, Bi JW, et al. The effect of perineural invasion on overall survival in patients with gastric carcinoma [J]. Gastrointest Sur.2008,12(7):1263-1267.
[72]Bachmann IM, H alvorsen OJ, Co llettK, et al. EZH 2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast[J]. J Clin Oncol.2006,24(2):268-273.
[73]Varambally S, Cao Q, Mani RS, et al. Genomic loss of microRNA-101 leads to overexpression of histone methyltransferase EZH2 in cancer[J]. Science.2008, 322:1695-1699.
[1]Jones PA, Baylin SB. The fundamental role of epigenetic events in cancer[J]. Nat Rev Genet. 2002,3:415-428.
[2]Laird PW. The power and the promise of DNA methylation markers[J]. Nat Rev Cancer.2003, 3:253-266.
[3]Ting AH, McGarvey KM, Baylin SB. The cancer epigenome--components and functional correlates[J]. Genes Dev.2006,20:3215-3231.
[4]Sparmann A, van Lohuizen M. Polycomb silencers control cell fate, development and cancer[J]. Nat Rev Cancer.2006,6:846-856.
[5]Fraga MF, Ballestar E, Villar-Garea A, et al. Loss of acetylation at Lys16 and trimethylation at Lys20 of histone H4 is a common hallmark of human cancer[J]. Nat Genet.2005, 37:391-400.
[6]Seligson DB, Horvath S, Shi T, et al. Global histone modification patterns predict risk of prostate cancer recurrence[J]. Nature.2005,435:1262-1266.
[7]Feinberg AP, Ohlsson R, Henikoff S. The epigenetic progenitor origin of human cancer[J]. Nat Rev Genet.2006,7:21-33.
[8]Chen H, Rossier C, Antonarakis SE. Cloning of a human homolog of the Drosophila enhancer of zeste gene (EZH2) that maps to chromosome 21q22.2[J]. Genomics.1996,38:30-37.
[9]Cardoso C, Mignon C, Hetet G, et al. The human EZH2 gene:genomic organisation and revised mapping in 7q35 within the critical region for malignant myeloid disorders[J]. Eur J Hum Genet.2000,8:174-180.
[10]Cardoso C, Timsit S, Villard L,et al. Specific interaction between the XNP/ATR-X gene product and the SET domain of the human EZH2 protein[J]. Hum Mol Genet.1998, 7:679-684.
[11]Qian C, Zhou MM. SET domain protein lysine methyltransferases:Structure, specificity and catalysis[J]. Cell Mol Life.2006,63:2755-2763.
[12]Aravind L, Iyer LM. Provenance of SET-domain histone methyltransferases through duplication of a simple structural unit[J]. Cell Cycle.2003,2:369-376.
[13]Cao R, Zhang Y. The functions of E(Z)/EZH2-mediated methylation of lysine 27 in histone H3[J]. Curr Opin Genet Dev.2004,14:155-164.
[14]Cao R, Wang L, Wang H, et al. Role of histone H3 lysine 27 methylation in Polycomb-group silencing[J]. Science.2002,298:1039-1043.
[15]Rea S, Eisenhaber F, O'Carroll D, et al. Regulation of chromatin structure by site-specific histone H3 methyltransferases[J]. Nature.2000,406:593-599.
[16]Montgomery ND, Yee D, Chen A, et al. The murine polycomb group protein Eed is required for global histone H3 lysine-27 methylation[J]. Curr Biol.2005,15:942-947.
[17]Ketel CS, Andersen EF, Vargas ML, et al. Subunit contributions to histone methyltransferase activities of fly and worm polycomb group complexes[J]. Mol Cell Biol.2005, 25:6857-6868.
[18]Nekrasov M, Klymenko T, Fraterman S, et al. Pcl-PRC2 is needed to generate high levels of H3-K27 trimethylation at Polycomb target genes[J]. EMBO J.2007,26:4078-4088.
[19]Vire E, Brenner C, Deplus R,et al. The Polycomb group protein EZH2 directly controls DNA methylation[J]. Nature.2006,439:871-874.
[20]McGarvey KM, Greene E, Fahrner JA, et al. DNA methylation and complete transcriptional silencing of cancer genes persist after depletion of EZH2[J]. Cancer Res.2007, 67:5097-5102.
[21]Ohm JE, McGarvey KM, Yu X, et al. A stem cell-like chromatin pattern may predispose tumor suppressor genes to DNA hypermethylation and heritable silencing[J]. Nat Genet. 2007,39:237-242.
[22]Schlesinger Y, Straussman R, Keshet I, et al. Polycomb-mediated methylation on Lys27 of histone H3 pre-marks genes for de novo methylation in cancer[J]. Nat Genet.2007, 39:232-236.
[23]Widschwendter M, Fiegl H, Egle D, et al. Epigenetic stem cell signature in cancer[J]. Nat Genet.2007,39:157-158.
[24]Kirmizis A, Bartley SM, Kuzmichev A, et al. Silencing of human polycomb target genes is associated with methylation of histone H3 Lys 27[J]. Genes Dev.2004,18:1592-1605.
[25]Villa R, Pasini D, Gutierrez A, et al. Role of the polycomb repressive complex 2 in acute promyelocytic leukemia[J]. Cancer Cell.2007,11:513-525.
[26]Tie F, Furuyama T, Prasad-Sinha J, et al. The Drosophila Polycomb Group proteins ESC and E(Z) are present in a complex containing the histone-binding protein p55 and the histone deacetylase RPD3[J]. Development.2001,128:275-286.
[27]Varambally S, Dhanasekaran SM, Zhou M, et al. The polycomb group protein EZH2 is involved in progression of prostate cancer[J]. Nature.2002,419:624-629.
[28]Bracken AP, Pasini D, Capra M, et al. EZH2 is downstream of the pRB-E2F pathway, essential for proliferation and amplified in cancer[J]. EMBO J.2003,22:5323-5335.
[29]Rhodes DR, Sanda MG, Otte AP, et al. Multiplex biomarker approach for determining risk of prostate-specific antigen-defined recurrence of prostate cancer[J]. J Natl Cancer Inst.2003, 95:661-668.
[30]Saramaki OR, Tammela TL, Martikainen PM, et al. The gene for polycomb group protein enhancer of zeste homolog 2 (EZH2) is amplified in late-stage prostate cancer[J]. Genes Chromosomes Cancer.2006,45:639-645.
[31]Collett K, Eide GE, Arnes J, et al. Expression of enhancer of zeste homologue 2 is significantly associated with increased tumor cell proliferation and is a marker of aggressive breast cancer[J]. Clin Cancer Res.2006,12:1168-1174.
[32]Bachmann IM, Halvorsen OJ, Collett K, et al. EZH2 expression is associated with high proliferation rate and aggressive tumor subgroups in cutaneous melanoma and cancers of the endometrium, prostate, and breast[J]. J Clin Oncol.2006,24:268-273.
[33]Kleer CG, Cao Q, Varambally S, et al. EZH2 is a marker of aggressive breast cancer and promotes neoplastic transformation of breast epithelial cells[J]. Proc Natl Acad.2003, 100:11606-11611.
[34]Ding L, Erdmann C, Chinnaiyan AM, et al. Identification of EZH2 as a molecular marker for a precancerous state in morphologically normal breast tissues[J]. Cancer Res.2006, 66:4095-4099.
[35]Cha TL, Zhou BP, Xia W, et al. Akt-mediated phosphorylation of EZH2 suppresses methylation of lysine 27 in histone H3[J]. Science.2005,310:306-310.
[36]Li X, Gonzalez ME, Toy K,et al. Targeted overexpression of EZH2 in the mammary gland disrupts ductal morphogenesis and causes epithelial hyperplasia[J]. Am J Pathol. 2009, 175:1246-1254.
[37]Endoh M, Endo TA, Endoh T, et al. Polycomb group proteins RinglA/B are functionally linked to the core transcriptional regulatory circuitry to maintain ES cell identity [J]. Development.2008,135:1513-1524.
[38]Rinn JL, Kertesz M, Wang JK, et al. Functional demarcation of active and silent chromatin domains in human HOX loci by noncoding RNAs[J]. Cell.2007,129:1311-1323.
[39]Schwartz YB, Pirrotta V. Polycomb silencing mechanisms and the management of genomic programmes[J]. Nat Rev Genet.2007,8:9-22.
[40]Boyer LA, Plath K, Zeitlinger J, et al. Polycomb complexes repress developmental regulators in murine embryonic stem cells[J]. Nature.2006,441:349-353.
[41]Bracken AP, Dietrich N, Pasini D, et al. Genome-wide mapping of Polycomb target genes unravels their roles in cell fate transitions[J]. Genes Dev.2006,20:1123-1136.
[42]Levine SS, Weiss A, Erdjument-Bromage H, et al. The core of the polycomb repressive complex is compositionally and functionally conserved in flies and humans[J]. Mol Cell Biol. 2002,22:6070-6078.
[43]Fischle W, Wang Y, Jacobs SA, et al. Molecular basis for the discrimination of repressive methyl-lysine marks in histone H3 by Polycomb and HP1 chromodomains[J]. Genes Dev. 2003,17:1870-1881.
[44]Francis NJ, Kingston RE, Woodcock CL. Chromatin compaction by a polycomb group protein complex[J]. Science.2004,306:1574-1577.
[45]Cao R, Tsukada Y, Zhang Y. Role of Bmi-1 and RinglA in H2A ubiquitylation and Hox gene siIencing[J]. Mol Cell,2005,20:845-854.
[46]Zeitlinger J, Stark A, Kellis M, et al. RNA polymerase stalling at developmental control genes in the Drosophila melanogaster embryo[J]. Nat Genet.2007,39:1512-1516.
[47]Guenther MG, Levine SS, Boyer LA, et al. A chromatin landmark and transcription initiation at most promoters in human cells[J]. Cell.2007,130:77-88.
[48]Stock JK, Giadrossi S, Casanova M, et al. Ringl-mediated ubiquitination of H2A restrains poised RNA polymerase II at bivalent genes in mouse ES cells[J]. Nat Cell Biol.2007, 9:1428-1435.
[49]Su IH, Dobenecker MW, Dickinson E, et al. Polycomb group protein ezh2 controls actin polymerization and cell signaling[J]. Cell.2005,121:425-436.
[50]Bryant RJ, Winder SJ, Cross SS, et al. The Polycomb Group protein EZH2 regulates actin polymerization in human prostate cancer cells[J]. Prostate.2008,68:255-263.
[51]Bryant RJ, Cross NA, Eaton CL, et al. EZH2 promotes proliferation and invasiveness of prostate cancer cells[J]. Prostate.2007,67:547-556.
[52]Tolhuis B, de Wit E, Muijrers I, et al. Genome-wide profiling of PRC1 and PRC2 Polycomb chromatin binding in Drosophila melanogaster[J]. Nat Genet.2006,38:694-699.
[53]Negre N, Hennetin J, Sun LV, et al. Chromosomal distribution of PcG proteins during Drosophila development J]. PLoS Biol.2006,4:e170.
[54]Richter GH, Plehm S, Fasan A, et al. EZH2 is a mediator of EWS/FLI1 driven tumor growth and metastasis blocking endothelial and neuro-ectodermal differentiation[J]. Proc Natl Acad.2009,106:5324-5329.
[55]Chang CJ, Yang JY, Xia W, et al. EZH2 promotes expansion of breast tumor initiating cells through activation of RAFl-beta-catenin signaling[J]. Cancer Cell.2011,19:86-100.
[56]Chen S, Bohrer LR, Rai AN, et al. Cyclin-dependent kinases regulate epigenetic gene silencing through phosphorylation of EZH2[J]. Nat Cell Biol.2010,12:1108-1114.
[57]Wei Y, Chen YH, Li LY, et al. CDK1-dependent phosphorylation of EZH2 suppresses methylation of H3K27 and promotes osteogenic differentiation of human mesenchymal stem cells[J]. Nat Cell Biol.2011,13:87-94.
[58]Cao Q, Yu J, Dhanasekaran SM, et al. Repression of E-cadherin by the polycomb group protein EZH2 in cancer[J]. Oncogene.2008,27:7274-7284.
[59]Min J, Zaslavsky A, Fedele G, et al. An oncogene-tumor suppressor cascade drives metastatic prostate cancer by coordinately activating Ras and nuclear factor-kappaB[J]. Nat Med.2010, 16:286-294.
[60]Yu J, Cao Q, Mehra R, et al. Integrative genomics analysis reveals silencing of beta-adrenergic signaling by polycomb in prostate cancer[J]. Cancer Cell.2007,12:419-431.
[61]Lu C, Han HD, Mangala LS, et al. Regulation of tumor angiogenesis by EZH2[J]. Cancer Cell.2010,18:185-197.
[62]Schwartz YB, Kahn TG, Nix DA, et al. Genome-wide analysis of Polycomb targets in Drosophila melanogaster[J]. Nat Genet.2006,38:700-705.
[63]Piunti A, Pasini D. Epigenetic factors in cancer development:polycomb group proteins[J]. Future Oncol.2011,7:57-75.
[64]Visvader JE, Lindeman GJ. Cancer stem cells in solid tumours:accumulating evidence and unresolved questions[J]. Nat Rev Cancer.2008,8:755-768.
[65]Bernstein BE, Mikkelsen TS, Xie X, et al. A bivalent chromatin structure marks key developmental genes in embryonic stem cells[J]. Cell.2006,125:315-326.
[66]Jepsen K, Solum D, Zhou T, et al. SMRT-mediated repression of an H3K27 demethylase in progression from neural stem cell to neuron[J]. Nature.2007,450:415-419.
[67]Agger K, Cloos PA, Christensen J, et al. UTX and JMJD3 are histone H3K27 demethylases involved in HOX gene regulation and development[J]. Nature.2007,449:731-734.
[68]Lobo NA, Shimono Y, Qian D, et al. The biology of cancer stem cells[J]. Annu Rev Cell Dev Biol.2007,23:675-699.
[69]Stingl J, Caldas C. Molecular heterogeneity of breast carcinomas and the cancer stem cell hypothesis[J]. Nat Rev Cancer.2007,7:791-799.