5-Aza-CdR对绒毛膜癌细胞JEG-3 Dnmts/Mbd2表达及生长调控的研究
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摘要
绒毛膜癌(chorionic carcinoma,CH)简称绒癌,是一种极为常见的、高度恶性的妊娠性滋养细胞肿瘤( gestational trophoblastic neoplasia,GTN),其临床治疗以化疗为主,治愈率可达90%。然而,近年来难治性、多药耐药性绒癌的增多,使临床治愈率大大降低,因此寻找安全、有效且毒副作用小的抗绒癌药物,首要解决的问题就是阐明绒癌发生的机制。绒癌发病机制较为复杂,遗传学研究显示多种原癌基因、抑癌基因、细胞转录因子的表达异常以及激素水平异常与其发病相关[1,2]。目前研究发现,由表观遗传,如DNA甲基化异常引发的基因转录异常可能在绒癌的发生机制中发挥重要作用,但是其机制并不明了。DNA甲基化是一个逆转的修饰过程,且该逆转可直接恢复肿瘤细胞中某些抑癌基因的功能[3-6]。因此,从控制DNA甲基化的关键酶的表达角度去探讨绒癌的增殖、侵袭和凋亡等绒癌发生中的重要事件,可为临床上认识并寻找新的治疗策略提供实验依据。
本研究采用不同浓度(1、4、8、16、32μmol/L)DNA甲基化酶抑制剂5-Aza-CdR处理绒毛膜癌JEG-3细胞,应用Real Time PCR及Western印迹检测5-Aza-CdR处理细胞后DNA甲基化转移酶(DNAmethyltransferases,Dnmts)、DNA去甲基化酶(Methyl-DpG binding domain protein 2,Mbd2)mRNA及其蛋白的表达变化。进一步研究其对细胞生长特征的影响,包括细胞形态学变化、细胞增殖水平变化、细胞凋亡及细胞侵袭能力的改变。研究发现:
(1) Real Time PCR检测Dnmt1、Dnmt3a mRNA的表达显示,5-Aza-CdR可降低Dnmt1、Dnmt3a mRNA的表达,且呈剂量依赖关系,与对照组相比差异显著(P <0.05)。而Dnmt3b、Mbd2 mRNA表达水平几乎未受到影响,与对照组相比,无统计学意义(P >0.05)。
(2) Western-blotting结果显示,5-Aza-CdR可明显降低Dnmt1、Dnmt3a mRNA的表达水平,并呈剂量依赖关系(P <0.05);Dnmt3b、Mbd2蛋白表达差异不明显(P >0.05)。
(3)用5-Aza-CdR处理JEG-3细胞48 h后,显微镜观察发现细胞明显皱缩、细胞核聚集成块,死亡漂浮细胞明显增多,细胞长势较差。
(4) MTT实验结果显示,不同浓度的5-Aza-CdR均可抑制JEG-3细胞增殖,并呈剂量和时间依赖关系。
(5)流式细胞术检测结果显示,随着5-Aza-CdR浓度的增加,JEG-3细胞凋亡率显著增加(P <0.01)。5-Aza-CdR可促进细胞凋亡。
(6) Transwell小室检测5-Aza-CdR对JEG-3细胞侵袭能力表明10μmol/L的5-Aza-CdR可显著降低细胞的侵袭能力(P <0.01)。
综上,5-Aza-CdR可抑制Dnmt1、Dnmt3a mRNA和蛋白的表达。而不影响Dnmt3b、Mbd2mRNA和蛋白的表达。5-Aza-CdR可致JEG-3细胞皱缩、细胞核聚集成块,可明显抑制细胞增殖,促进其凋亡,降低细胞的侵袭力。Dnmt1、Dnmt3a可能在绒癌的增殖、侵袭和凋亡中发挥着重要作用。
horionic carcinoma called choriocarcinoma for short,is an extremely common and highly malignant gestational trophoblastic neoplasia. Chemotherapy is the main clinical therapy , the cure rate can reach to 90%. However,in recent years,with the increase of multidrug-resistant chorioepithelioma which is difficult to cure, the clinic cure rate is decreased significantly.So before seeking for anti-chorioepithelioma drug,which is safe,effective,and with small toxic and side-effect,the most important thing is to clarify the mechanism of occurrence of choriocarcinoma.The pathological mechanism of chorioepielioma is complicate.The studies on genetic have shown a variety of oncogenes, tumor suppressor genes, abnormal expression of cellular transcription factors, and abnormal hormone levels associated with this disease [1,2].Present researches find the abnormal transcription of genes can induce by epigenetic, such as DNA methylation abnormalities which may be play an important role in the pathogenesis of choriocarcinoma.But it is not clear at present.DNA methylation is a reversible modification process,and the reversal of tumor cells can directly restore the function of certain tumor suppressor genes[3-6].Therefore,to study on point of view in DNA methyltransferase,cell proliferation,invasion and apoptosis can provide some fundamental experimental evidence for new strategy of the chorioepielioma treatment.
We treated the choriocarcinoma JEG-3 cells with different concentrations(1,4,8,16,32μmol/L)of the DNA methyltransferase inhibitor 5-Aza-CdR.Then we used Real Time PCR and Western blotting to detect the change of mRNA and protein of DNA methyltransferases,DNA demethylase.Further more changes of cell morphology were observed under the microscope,and cell proliferation was detected by MTT.Flow Cytometry was used to detected JEG-3 cell apoptosis,and Transwell chamber measured the invasion of JEG-3 cells.
Real Time PCR 5-Aza-CdR could significantly reduce the Dnmt1,Dnmt3a expression levels in a dose dependent manner,compared with the control degree of significant difference(P<0.05),and it could not affect the expression of (P> 0.05).
(2) Western blotting results showed the same results as the Real Time PCR.5-Aza-CdR could significantly reduce the (P<0.05),and it could not affect the expression of (P>0.05).
(3) After treatment JEG-3 cells with 5-Aza-CdR for 48 h,we observed by the microscope that the cells showed shrinkage,nuclear poly integrated block.Floating dead cells were significantly increased and cells grew badly.
(4) MTT experiment results showed that different concentrations of 5-Aza-CdR could inhibit the proliferation of JEG-3 cells in a dose and time dependent manner.
(5) The cell apoptosis was dected by flow cytometry.We found that the apoptosis rate was significantly increased with the multiplicative concentration of 5-Aza-CdR(P<0.01).
(6) The invasion of JEG-3 was tested by Transwell small chamber. 5-Aza-CdR treatment led to depression of the cell invasiveness.There was a significant difference compared with the control group(P<0.01).
5-Aza-CdR can inhibit the Dnmt1,Dnmt3a mRNA and protein expression remarkably,but it does not affect the Dnmt3b,Mbd2 mRNA and protein expression.5-Aza-CdR can also induce JEG-3 cell shrinkage,nuclear poly blocks,inhibit the cell proliferation and induce apoptosis and reduce the cell invasiveness.Dnmt1,Dnmt3a may play an important role in choriocarcinoma proliferation,invasion and apoptosis.
本研究采用不同浓度(1、4、8、16、32μmol/L)DNA甲基化酶抑制剂5-Aza-CdR处理绒毛膜癌JEG-3细胞,应用Real Time PCR及Western印迹检测5-Aza-CdR处理细胞后DNA甲基化转移酶(DNAmethyltransferases,Dnmts)、DNA去甲基化酶(Methyl-DpG binding domain protein 2,Mbd2)mRNA及其蛋白的表达变化。进一步研究其对细胞生长特征的影响,包括细胞形态学变化、细胞增殖水平变化、细胞凋亡及细胞侵袭能力的改变。研究发现:
(1) Real Time PCR检测Dnmt1、Dnmt3a mRNA的表达显示,5-Aza-CdR可降低Dnmt1、Dnmt3a mRNA的表达,且呈剂量依赖关系,与对照组相比差异显著(P <0.05)。而Dnmt3b、Mbd2 mRNA表达水平几乎未受到影响,与对照组相比,无统计学意义(P >0.05)。
(2) Western-blotting结果显示,5-Aza-CdR可明显降低Dnmt1、Dnmt3a mRNA的表达水平,并呈剂量依赖关系(P <0.05);Dnmt3b、Mbd2蛋白表达差异不明显(P >0.05)。
(3)用5-Aza-CdR处理JEG-3细胞48 h后,显微镜观察发现细胞明显皱缩、细胞核聚集成块,死亡漂浮细胞明显增多,细胞长势较差。
(4) MTT实验结果显示,不同浓度的5-Aza-CdR均可抑制JEG-3细胞增殖,并呈剂量和时间依赖关系。
(5)流式细胞术检测结果显示,随着5-Aza-CdR浓度的增加,JEG-3细胞凋亡率显著增加(P <0.01)。5-Aza-CdR可促进细胞凋亡。
(6) Transwell小室检测5-Aza-CdR对JEG-3细胞侵袭能力表明10μmol/L的5-Aza-CdR可显著降低细胞的侵袭能力(P <0.01)。
综上,5-Aza-CdR可抑制Dnmt1、Dnmt3a mRNA和蛋白的表达。而不影响Dnmt3b、Mbd2mRNA和蛋白的表达。5-Aza-CdR可致JEG-3细胞皱缩、细胞核聚集成块,可明显抑制细胞增殖,促进其凋亡,降低细胞的侵袭力。Dnmt1、Dnmt3a可能在绒癌的增殖、侵袭和凋亡中发挥着重要作用。
horionic carcinoma called choriocarcinoma for short,is an extremely common and highly malignant gestational trophoblastic neoplasia. Chemotherapy is the main clinical therapy , the cure rate can reach to 90%. However,in recent years,with the increase of multidrug-resistant chorioepithelioma which is difficult to cure, the clinic cure rate is decreased significantly.So before seeking for anti-chorioepithelioma drug,which is safe,effective,and with small toxic and side-effect,the most important thing is to clarify the mechanism of occurrence of choriocarcinoma.The pathological mechanism of chorioepielioma is complicate.The studies on genetic have shown a variety of oncogenes, tumor suppressor genes, abnormal expression of cellular transcription factors, and abnormal hormone levels associated with this disease [1,2].Present researches find the abnormal transcription of genes can induce by epigenetic, such as DNA methylation abnormalities which may be play an important role in the pathogenesis of choriocarcinoma.But it is not clear at present.DNA methylation is a reversible modification process,and the reversal of tumor cells can directly restore the function of certain tumor suppressor genes[3-6].Therefore,to study on point of view in DNA methyltransferase,cell proliferation,invasion and apoptosis can provide some fundamental experimental evidence for new strategy of the chorioepielioma treatment.
We treated the choriocarcinoma JEG-3 cells with different concentrations(1,4,8,16,32μmol/L)of the DNA methyltransferase inhibitor 5-Aza-CdR.Then we used Real Time PCR and Western blotting to detect the change of mRNA and protein of DNA methyltransferases,DNA demethylase.Further more changes of cell morphology were observed under the microscope,and cell proliferation was detected by MTT.Flow Cytometry was used to detected JEG-3 cell apoptosis,and Transwell chamber measured the invasion of JEG-3 cells.
Real Time PCR 5-Aza-CdR could significantly reduce the Dnmt1,Dnmt3a expression levels in a dose dependent manner,compared with the control degree of significant difference(P<0.05),and it could not affect the expression of (P> 0.05).
(2) Western blotting results showed the same results as the Real Time PCR.5-Aza-CdR could significantly reduce the (P<0.05),and it could not affect the expression of (P>0.05).
(3) After treatment JEG-3 cells with 5-Aza-CdR for 48 h,we observed by the microscope that the cells showed shrinkage,nuclear poly integrated block.Floating dead cells were significantly increased and cells grew badly.
(4) MTT experiment results showed that different concentrations of 5-Aza-CdR could inhibit the proliferation of JEG-3 cells in a dose and time dependent manner.
(5) The cell apoptosis was dected by flow cytometry.We found that the apoptosis rate was significantly increased with the multiplicative concentration of 5-Aza-CdR(P<0.01).
(6) The invasion of JEG-3 was tested by Transwell small chamber. 5-Aza-CdR treatment led to depression of the cell invasiveness.There was a significant difference compared with the control group(P<0.01).
5-Aza-CdR can inhibit the Dnmt1,Dnmt3a mRNA and protein expression remarkably,but it does not affect the Dnmt3b,Mbd2 mRNA and protein expression.5-Aza-CdR can also induce JEG-3 cell shrinkage,nuclear poly blocks,inhibit the cell proliferation and induce apoptosis and reduce the cell invasiveness.Dnmt1,Dnmt3a may play an important role in choriocarcinoma proliferation,invasion and apoptosis.
引文
[1]李学农,李亚玲,刘国炳,等。应用生物信息学技术筛查绒毛膜癌相关基因,第一军医大学学报,2005,25(1)
[2] Jain P,cietak KA.Post-tern choriocarcinoma with unnsually low beat-hCG,J Obstet Gynaecol,2008,28(6): 661-662
[3] Wei-Cheng Xue,Annie N.Y. Cheung et al.Promoter Hypermethylation of Multiple Genes in Hydatidiform Mole and Choriocarcinoma. Journal of Molecular Diagnostics, 2004; 6(4):326-334.
[4] Hube F, Reverdiau P, Iochmann S, Rollin J, Cherpi-Antar C, Gruel Y: Transcriptional silencing of the TFPI-2 gene by promoter hypermethylation in choriocarcinoma cells. Biol Chem 2003; 384:1029–1034.
[5] Kanduri C, Kanduri M, Liu L, Thakur N, Pfeifer S, Ohlsson R: The kinetics of deregulation of expression by de novo methylation of the h19 imprinting control region in cancer cells. Cancer Res 2002; 62:4545–4548
[6] Arima T, Matsuda T, Takagi N, Wake N: Association of IGF2 and H19 imprinting with choriocarcinoma development. Cancer Genet Cytogenet 1997, 93:39–47.
[7] Bestor T,Laudano A,,Mattaliano R, et al. Cloning and sequencing of a cDNAencoding DNA methyltransferase of mouse cells. The carboxyl-terminal domainof the mammalian enzymes is related to bacterial restriction methyltransferases[J]. J Mol Biol, 1988(4), 203: 971-983
[8] Al-Nasiry S, Spitz B, Hanssens M, Luyten C and Pijnenborg R Differential effects of inducers of syncytialization and apoptosis on BeWo and JEG-3 choriocarcinoma cells,Hum Reprod,2006,21: 193-201
[9] Lee S, Lee HJ, Kim JH, Lee HS, Jang JJ, Kang GH. Aberrant CpG island hypermethylation along multistep hepatocarcinogenesis. Am J Pathol 2003; 163: 1371-1378
[10] Kerbel RS. Growth dominance of the metastatic cancer cell: cellular and molecular aspects. Adv Cancer Res 1990; 55: 87-132
[11]汪建平,元云飞。结直肠癌DNA甲基化研究的现状。中华实验外科杂志,2004,21:1279-1280。
[12]薛京伦,汪旭,吴超群。表观遗传学—原理、技术与实践。上海,上海科学技术出版社,2006,312-14
[13] Obin LH, Fleming ID. TNM classification of malignant tumors, fifth edition (1997). Union Internationale Contre le Cancer and the American Joint Committee on Cancer. Cancer 1997; 80: 1803-1804
[14] Christman JK. 5-azacytidine and 5-aza-2′-deoxycytidine as inhibitors of DNA methylation: mechanistic studies and their implications for cancer therapy. Oncogene 200221: 5483-5495
[15] Aoki A, Suetake I, Miyagawa J, et al. (2001) Enzymatic properties of de novo-type mouse DNA (cytosine-5)-methyltransferases. Nucleic Acids Res 29: 3506-3512
[16] Schneider-Stock R, Diab-Assef M, Rohrbeck A, et al. 5-Aza-cytidine is a potent inhibitor of DNA methyltransferase 3a and induces apoptosis in HCT-116 colon cancer cells via Gadd45- and p53-dependent mechanisms. J Pharmacol Exp Ther ,2005,312: 525-536
[17] Meng F, Wehbe-Janek H, Henson R, et al. Epigenetic regulation of microRNA-370 by interleukin-6 in malignant human cholangiocytes. Oncogene, 2008,27: 378-386
[18] Xue WC, Chan KY, Feng HC, Chiu PM, Ngan HY, Tsao SW, Cheung AN. Promoter hypermethylation of multiple genes in hydatidiform mole and choriocarcinoma. J Mol Diagn 2004; 6: 326-334
[19] Kim H, Kim YH, Kim SE, Kim NG, Noh SH, Kim H. Concerted promoter hypermethylation of hMLH1, p16INK4A, and E-cadherin in gastric carcinomas with microsatellite instability. J Pathol 2003; 200: 23-31
[1] Brown R,Strathdee G,Epigenomics and epigenetic therapy of cancer[J].Trends Mol Med,2002,8(suppl4):43-48.
[2] Strathdee G,Brown R . Epigenetic cancer therapies:DNA methyl-transferase inhibit or s [J].Expert Opin Investig Drugs,2002,11(6):747-75.
[3] Robertson l .DNA methylation and human diseasel J 1.Nature Reviews Genetics,2005;6:597-610.
[4] Fuks F,Hurd PJ,W0lfD.n1e methyl CpG binding protein MecPlinks DNA methylation to histone methylatin[J].J Bilo Chem,2003; 278: 4035-40.
[5] Paz MF,Fraga MF,Avila S,et al. A systematic profile of DNA methylation in human cancer cell lices.Cancer Res,2003,63(5):1114-1121.
[6] Yang B,Guo M,Herman JG,Clark DP.Aberrant promoter methylation profiles of tumor suppressor genes in heaptocellular carcinoma.Am Jpethol,2003,163(3):1101-7.
[7] Waterland RA,Lin JR,Smith CA,et al. Post-weaning diet affects genomic imprinting at t he insulin-like growth factor 2(Igf2)locus.Hum Mol Genet,2006,15(5):705-16.
[8] Matsuda Y,Ichida T,Matsuzawa J,et al. CpG island methylator phenotype is a strong determinant of poor prognosis in neuroblastomas.Canccer Res,2005,65(3): 828-34.
[9] Wainfan E,Poirier LA . Methylgroups in carcinogenesis : effects on DNA methylation and gene expression Cancer Res.1992,52(7 Supp1): 2071-7.
[10] Van Engeland M,Weijenberg MP,Rcemen GM,et al.Effects of dietary folate and alcohol in-take on promoter methylation in sporadic colorectal cancer: the Netherlands cohort study on diet and cancer . Cancer Res,2003,63(12) :3133-3137.
[11] Kawasaki H,Taira K.Induction of DNA methylation and gene silencing by short interfering RNAs in human cells Nature,2004,431(7005):212-217.
[12] Veigl ML,Kasturi L,Olechnowicz J,et al.Biallelic inactivation of hMLH1 by epigeneticgene silencing,anovel mechanism causing human MSI cancers Proc Netl Acead Sci USA,1998,95(15): 8698-8702.
[13] Fang MZ,Jin Z,Wang Y,et al.Promoter hypermethylatior and inactivation of o’met hyguanine DNA methyllransferas einesophageal squamous cell carcinomas and its reactivation incelfnes Int J Onco.2005,26(3):615-22.
[14] An C ,Choi IS,Yao JC,Worah S,et al. Prognostic significance of CpG island methylator phenotype and microsatellite instability in gastric carcinoma.Clin Cancer Res,2005, 1(2Pl1):656-63.
[15] Feinberg AP,Ohlesson R,Henikoff S.The epigenetic progenitor origin of human cancer. Nat Rev Gennet 2006;7:21-33
[16] Sakatani T, Kaneda A, Iacobuzio-Donahue CA,Carter MG, de Boom Witzel S,Okanno H, KoMS, Ohlsson R,Longo DL, Feinberg AP. Loss of imprinting of Igf2 alters intestinal maturation and tumorigenesis in mice. Science 2005;27:1976-1978
[17] Kato Y, Sasaki H. Imprinting and looping:epigenetic marks control interactions between regulatory elements. Bioessays 2005;27:1-4
[18] Holm TM,Jackson-Grusby L,Brambrink T,et al.Global loss of impringting leads to widespresad tumorigenesis in adult mice.Cancer Cell 2005;8:275-285
[19] Nakagawa T,Kanai Y,Ushiiima S,et al.DNA hypomethylatior on pericentromeric satellitere gions significantly correlates with loss of heterozygosisty or chromosome in urothelial heteozygosity on chromosome in urothelial carcinomas.Jurel,2005,173(1):243-246.
[20] Wong N,Lam WC,Lai PB, et al. Hypomethylation of chromosome 1 heteroc hromat in DNA correlates with qarmcopy gain in human heaptocellular carcinoma. Am J Pathef,2001,159(2): 465-471.
[21] Knowles MA.The genetics of transitional cell carcinoma progress and potential clinicl application BJ Int,1999,84(4): 412-427.
[22] Kokalj-Vokac N,Almeida A,Viegas-Pequignot E,et al.Specificinduction of uncoiling and recombination by azacytidine in classical satellite-coRtaining constitutive heteroch romatin Cytogenet Cell Genet,1993,63(1):11-15.
[23] Van’t Veer LJ, Dair H, et a1.Gene expression profiling predicts clinical out-come of breast cancer[J].Nature, 200; 415: 530-6
[24] Palmisano WA,Divine KK, Saccomanno G, et a1. Predicting lung cancer by detecting aberrant promoter methylation in sputum,Cancer Res, 2000, 60(21):5954-58.
[25] Goessl C,Krause H,Muller M,et al.Fluroent methylation specific polymerase chain reaction flour DNA-based detection of prostate cancer in bodily fluids[J].Cancer Res,200;60:594l-5.
[2] Jain P,cietak KA.Post-tern choriocarcinoma with unnsually low beat-hCG,J Obstet Gynaecol,2008,28(6): 661-662
[3] Wei-Cheng Xue,Annie N.Y. Cheung et al.Promoter Hypermethylation of Multiple Genes in Hydatidiform Mole and Choriocarcinoma. Journal of Molecular Diagnostics, 2004; 6(4):326-334.
[4] Hube F, Reverdiau P, Iochmann S, Rollin J, Cherpi-Antar C, Gruel Y: Transcriptional silencing of the TFPI-2 gene by promoter hypermethylation in choriocarcinoma cells. Biol Chem 2003; 384:1029–1034.
[5] Kanduri C, Kanduri M, Liu L, Thakur N, Pfeifer S, Ohlsson R: The kinetics of deregulation of expression by de novo methylation of the h19 imprinting control region in cancer cells. Cancer Res 2002; 62:4545–4548
[6] Arima T, Matsuda T, Takagi N, Wake N: Association of IGF2 and H19 imprinting with choriocarcinoma development. Cancer Genet Cytogenet 1997, 93:39–47.
[7] Bestor T,Laudano A,,Mattaliano R, et al. Cloning and sequencing of a cDNAencoding DNA methyltransferase of mouse cells. The carboxyl-terminal domainof the mammalian enzymes is related to bacterial restriction methyltransferases[J]. J Mol Biol, 1988(4), 203: 971-983
[8] Al-Nasiry S, Spitz B, Hanssens M, Luyten C and Pijnenborg R Differential effects of inducers of syncytialization and apoptosis on BeWo and JEG-3 choriocarcinoma cells,Hum Reprod,2006,21: 193-201
[9] Lee S, Lee HJ, Kim JH, Lee HS, Jang JJ, Kang GH. Aberrant CpG island hypermethylation along multistep hepatocarcinogenesis. Am J Pathol 2003; 163: 1371-1378
[10] Kerbel RS. Growth dominance of the metastatic cancer cell: cellular and molecular aspects. Adv Cancer Res 1990; 55: 87-132
[11]汪建平,元云飞。结直肠癌DNA甲基化研究的现状。中华实验外科杂志,2004,21:1279-1280。
[12]薛京伦,汪旭,吴超群。表观遗传学—原理、技术与实践。上海,上海科学技术出版社,2006,312-14
[13] Obin LH, Fleming ID. TNM classification of malignant tumors, fifth edition (1997). Union Internationale Contre le Cancer and the American Joint Committee on Cancer. Cancer 1997; 80: 1803-1804
[14] Christman JK. 5-azacytidine and 5-aza-2′-deoxycytidine as inhibitors of DNA methylation: mechanistic studies and their implications for cancer therapy. Oncogene 200221: 5483-5495
[15] Aoki A, Suetake I, Miyagawa J, et al. (2001) Enzymatic properties of de novo-type mouse DNA (cytosine-5)-methyltransferases. Nucleic Acids Res 29: 3506-3512
[16] Schneider-Stock R, Diab-Assef M, Rohrbeck A, et al. 5-Aza-cytidine is a potent inhibitor of DNA methyltransferase 3a and induces apoptosis in HCT-116 colon cancer cells via Gadd45- and p53-dependent mechanisms. J Pharmacol Exp Ther ,2005,312: 525-536
[17] Meng F, Wehbe-Janek H, Henson R, et al. Epigenetic regulation of microRNA-370 by interleukin-6 in malignant human cholangiocytes. Oncogene, 2008,27: 378-386
[18] Xue WC, Chan KY, Feng HC, Chiu PM, Ngan HY, Tsao SW, Cheung AN. Promoter hypermethylation of multiple genes in hydatidiform mole and choriocarcinoma. J Mol Diagn 2004; 6: 326-334
[19] Kim H, Kim YH, Kim SE, Kim NG, Noh SH, Kim H. Concerted promoter hypermethylation of hMLH1, p16INK4A, and E-cadherin in gastric carcinomas with microsatellite instability. J Pathol 2003; 200: 23-31
[1] Brown R,Strathdee G,Epigenomics and epigenetic therapy of cancer[J].Trends Mol Med,2002,8(suppl4):43-48.
[2] Strathdee G,Brown R . Epigenetic cancer therapies:DNA methyl-transferase inhibit or s [J].Expert Opin Investig Drugs,2002,11(6):747-75.
[3] Robertson l .DNA methylation and human diseasel J 1.Nature Reviews Genetics,2005;6:597-610.
[4] Fuks F,Hurd PJ,W0lfD.n1e methyl CpG binding protein MecPlinks DNA methylation to histone methylatin[J].J Bilo Chem,2003; 278: 4035-40.
[5] Paz MF,Fraga MF,Avila S,et al. A systematic profile of DNA methylation in human cancer cell lices.Cancer Res,2003,63(5):1114-1121.
[6] Yang B,Guo M,Herman JG,Clark DP.Aberrant promoter methylation profiles of tumor suppressor genes in heaptocellular carcinoma.Am Jpethol,2003,163(3):1101-7.
[7] Waterland RA,Lin JR,Smith CA,et al. Post-weaning diet affects genomic imprinting at t he insulin-like growth factor 2(Igf2)locus.Hum Mol Genet,2006,15(5):705-16.
[8] Matsuda Y,Ichida T,Matsuzawa J,et al. CpG island methylator phenotype is a strong determinant of poor prognosis in neuroblastomas.Canccer Res,2005,65(3): 828-34.
[9] Wainfan E,Poirier LA . Methylgroups in carcinogenesis : effects on DNA methylation and gene expression Cancer Res.1992,52(7 Supp1): 2071-7.
[10] Van Engeland M,Weijenberg MP,Rcemen GM,et al.Effects of dietary folate and alcohol in-take on promoter methylation in sporadic colorectal cancer: the Netherlands cohort study on diet and cancer . Cancer Res,2003,63(12) :3133-3137.
[11] Kawasaki H,Taira K.Induction of DNA methylation and gene silencing by short interfering RNAs in human cells Nature,2004,431(7005):212-217.
[12] Veigl ML,Kasturi L,Olechnowicz J,et al.Biallelic inactivation of hMLH1 by epigeneticgene silencing,anovel mechanism causing human MSI cancers Proc Netl Acead Sci USA,1998,95(15): 8698-8702.
[13] Fang MZ,Jin Z,Wang Y,et al.Promoter hypermethylatior and inactivation of o’met hyguanine DNA methyllransferas einesophageal squamous cell carcinomas and its reactivation incelfnes Int J Onco.2005,26(3):615-22.
[14] An C ,Choi IS,Yao JC,Worah S,et al. Prognostic significance of CpG island methylator phenotype and microsatellite instability in gastric carcinoma.Clin Cancer Res,2005, 1(2Pl1):656-63.
[15] Feinberg AP,Ohlesson R,Henikoff S.The epigenetic progenitor origin of human cancer. Nat Rev Gennet 2006;7:21-33
[16] Sakatani T, Kaneda A, Iacobuzio-Donahue CA,Carter MG, de Boom Witzel S,Okanno H, KoMS, Ohlsson R,Longo DL, Feinberg AP. Loss of imprinting of Igf2 alters intestinal maturation and tumorigenesis in mice. Science 2005;27:1976-1978
[17] Kato Y, Sasaki H. Imprinting and looping:epigenetic marks control interactions between regulatory elements. Bioessays 2005;27:1-4
[18] Holm TM,Jackson-Grusby L,Brambrink T,et al.Global loss of impringting leads to widespresad tumorigenesis in adult mice.Cancer Cell 2005;8:275-285
[19] Nakagawa T,Kanai Y,Ushiiima S,et al.DNA hypomethylatior on pericentromeric satellitere gions significantly correlates with loss of heterozygosisty or chromosome in urothelial heteozygosity on chromosome in urothelial carcinomas.Jurel,2005,173(1):243-246.
[20] Wong N,Lam WC,Lai PB, et al. Hypomethylation of chromosome 1 heteroc hromat in DNA correlates with qarmcopy gain in human heaptocellular carcinoma. Am J Pathef,2001,159(2): 465-471.
[21] Knowles MA.The genetics of transitional cell carcinoma progress and potential clinicl application BJ Int,1999,84(4): 412-427.
[22] Kokalj-Vokac N,Almeida A,Viegas-Pequignot E,et al.Specificinduction of uncoiling and recombination by azacytidine in classical satellite-coRtaining constitutive heteroch romatin Cytogenet Cell Genet,1993,63(1):11-15.
[23] Van’t Veer LJ, Dair H, et a1.Gene expression profiling predicts clinical out-come of breast cancer[J].Nature, 200; 415: 530-6
[24] Palmisano WA,Divine KK, Saccomanno G, et a1. Predicting lung cancer by detecting aberrant promoter methylation in sputum,Cancer Res, 2000, 60(21):5954-58.
[25] Goessl C,Krause H,Muller M,et al.Fluroent methylation specific polymerase chain reaction flour DNA-based detection of prostate cancer in bodily fluids[J].Cancer Res,200;60:594l-5.
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