5-Aza-2′-deoxycytidine is a potent inhibitor of DNA methyltransferase 3B and induces apoptosis in human endometrial cancer cell lines with the up-regulation of hMLH1

Min Cui1, Zeqing Wen1, Ji Chen2, Zhongli Yang1, Hualing Zhang1
1Department of Obstetrics and Gynecology, Shandong Provincial Hospital, Shandong University, Jinan, People’s Republic of China
2Department of Urology, Shandong Provincial Hospital, Shandong University, Jinan, People’s Republic of China

Tóm tắt

The aim of our study was to evaluate the effects of 5-aza-2′-deoxycytidine (5-azadC) on cell growth inhibition, cell cycle arrest, apoptosis as well as the expression levels of hMLH1 and DNMT3B in human endometrial cancer cell lines. Ishikawa, HHUA, and KLE cell lines were used. After treatment with 5-azadC, cells were measured by MTT to detect the growth inhibition. Flow cytometry analysis was used to evaluate the cell cycle distribution and apoptosis effect. The expression of hMLH1 and DNMT3B was performed by real-time PCR and Western blotting analysis. The methylation status of the hMLH1 gene was monitored by methylation-specific PCR. We confirmed that 5-azadC treatment resulted in growth inhibition, G2 arrest, and cell apoptosis in human endometrial cancer cell lines. Furthermore, the data obtained by real-time PCR and Western blotting analysis demonstrated that the expression of hMLH1 was up-regulated by 5-azadC treatment in Ishikawa cells, accompanied by down-regulation of DNMT3B expression, when 5-azadC led to cell inhibition, G2/M arrest, and apoptosis. Our results suggested that 5-azadC is a potent inhibitor of DNA methyltransferase 3B and induces apoptosis in Ishikawa cells with the up-regulation of hMLH1.

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Tài liệu tham khảo

Bird A. DNA methylation patterns and epigenetic memory. Genes Dev. 2002;16:6–21. doi:10.1101/gad.947102. Goll MG, Bestor TH. Eukaryotic cytosine methyltransferases. Annu Rev Biochem. 2005;74:481–514. doi:10.1146/annurev.biochem.74.010904.153721. Leonhardt H, Page AW, Weier HU, Bestor TH. A targeting sequence directs DNA methyltransferase to sites of DNA replication in mammalian nuclei. Cell. 1992;71:865–73. doi:10.1016/0092-8674(92)90561-P. Okano M, Bell DW, Haber DA, Li E. DNA methyltransferases Dnmt3a and Dnmt3b are essential for de novo methylation and mammalian development. Cell. 1999;99:247–57. doi:10.1016/S0092-8674(00)81656-6. Robertson KD. DNA methylation and human disease. Nat Rev Genet. 2005;6:597–610. doi:10.1038/nrg1655. Eden A, Gaudet F, Waghmare A, Jaenisch R. Chromosomal instability and tumors promoted by DNA hypomethylation. Science. 2003;300:455. doi:10.1126/science.1083557. Jones PA, Baylin SB. The fundamental role of epigenetic events in cancer. Nat Rev Genet. 2002;3:415–28. doi:10.1038/nrg962. Lax SF. Molecular genetic pathways in various types of endometrial carcinoma: from a phenotypical to a molecular-based classification. Virchows Arch. 2004;444:213–23. doi:10.1007/s00428-003-0947-3. Kanaya T, et al. Frequent hypermethylation of MLH1 promoter in normal endometrium of patients with endometrial cancers. Oncogene. 2003;22:2352–60. doi:10.1038/sj.onc.1206365. Zhu WG, Otterson GA. The interaction of histone deacetylase inhibitors and DNA methyltransferase inhibitors in the treatment of human cancer cells. Curr Med Chem Anticancer Agents. 2003;3:187–99. doi:10.2174/1568011033482440. Santini V, Kantarjian HM, Issa JP. Changes in DNA methylation in neoplasia: pathophysiology and therapeutic implications. Ann Intern Med. 2001;134:573–86. Christman JK. 5-Azacytidine and 5-aza-2′-deoxycytidine as inhibitors of DNA methylation: mechanistic studies and their implications for cancer therapy. Oncogene. 2002;21:5483–95. doi:10.1038/sj.onc.1205699. Petti MC, et al. Pilot study of 5-aza-2_-deoxycytidine (Decitabine) in the treatment of poor prognosis acute myelogenous leukemia patients: preliminary results. Leukemia. 1993;Suppl 1:36–41. Kitagawa Y, et al. Demethylating reagent 5-azacytidine inhibits teloemerase activity in human prostate cancer cells through transcriptional repression of hTERT. Clin Cancer Res. 2000;6:2868–75. Greger V, Passarge E, Hopping W, Messmer E, Horsthemke B. Epigenetic changes may contribute to the formation and spontaneous regression of retinoblastoma. Hum Genet. 1989;83:155–8. doi:10.1007/BF00286709. Baylin SB, et al. Aberrant patterns of DNA methylation, chromatin formation and gene expression in cancer. Hum Mol Genet. 2001;10:687–92. doi:10.1093/hmg/10.7.687. Salvesen HB, et al. PTEN methylation is associated with advanced stage and microsatellite instability in endometrial carcinoma. Int J Cancer. 2001;91:22–6. doi:10.1002/1097-0215(20010101)91:1<L22::AID-IJC1002>3.0.CO;2-S. Aebi S, et al. Loss of DNA mismatch repair in acquired resistance to cisplatin. Cancer Res. 1996;56:3087–90. Sasaki M, Dharia A, Oh BR, Tanaka Y, Fujimoto S, Dahiya R. Progesterone receptor B gene inactivation and CpG hypermethylation in human uterine endometrial cancer. Cancer Res. 2001;61:97–102. Gurin CC, Federici MG, Kang L, Boyd J. Causes and consequences of microsatellite instability in endometrial carcinoma. Cancer Res. 1999;59:462–6. Bird AP. The relationship of DNA methylation to cancer. Cancer Surv. 1996;28:87–101. Issa JP. Optimizing therapy with methylation inhibitors in myelodysplastic syndromes: dose, duration, and patient selection. Nat Clin Pract Oncol. 2005;2:S24–9. doi:10.1038/ncponc0355. Issa JP, H Kantarjian. Azacitidine. Nat Rev Drug Discov. 2005;Suppl:S6–S7. doi:10.1038/nrd1726. Momparler RL. Pharmacology of 5-aza-2′-deoxycytidine (decitabine). Semin Hematol. 2005;42:S9–16. doi:10.1053/j.seminhematol.2005.05.002.