Jing-Yuan Fang1, Juan Lu, Ying-Xuan Chen, Li Yang. 1. Shanghai Institute of Digestive Diseases, Renji Hospital, Shanghai Second Medical University, Shanghai 200001, China. jingyuanfang@yahoo.com
Abstract
AIM: To investigate the effects of DNA methylation on the expression of tumor suppressor genes and proto-oncogene in human colon cancer cell lines. METHODS: Three colon cancer cell lines (HT-29, SW1116 and Colo-320) treated with different concentrations of DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC) were used to induce DNA demethylation. The expressions of p16(INK4A), p21(WAF1), APC and c-myc genes were observed by using RT-PCR. The methylation status of p16(INK4A) promoter in HT-29 cells was also determined by methylation-specific PCR (MSP). RESULTS: Weak expressions of p16(INK4A) and APC in the three colon cancer cells were detected, and p21(WAF1) expression was not found in SW1116 and Colo-320 cells before treatment. After treatment of 1 micromol/L but not 10 micromol/L of 5-aza-dC, the methylation level of p16(INK4A) gene promoter decreased significantly, and the hypomethylation led to the up-regulation of p16(INK4A) gene transcription in HT-29 cells. In the cell lines of SW1116 and Colo-320, p16(INK4A) and APC mRNA expressions were obviously enhanced after treatment of either 10 micromol/L or 5 micromol/L 5-aza-dC for 24 h. However, no evidence was found that methylation regulated the expression of p21(WAF1) and c-myc genes in human colon cancer cell lines. CONCLUSION: Expression of p16(INK4A) and APC genes is regulated by DNA methylation in three human colon cancer cell lines.
AIM: To investigate the effects of DNA methylation on the expression of tumor suppressor genes and proto-oncogene in humancolon cancer cell lines. METHODS: Three colon cancer cell lines (HT-29, SW1116 and Colo-320) treated with different concentrations of DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC) were used to induce DNA demethylation. The expressions of p16(INK4A), p21(WAF1), APC and c-myc genes were observed by using RT-PCR. The methylation status of p16(INK4A) promoter in HT-29 cells was also determined by methylation-specific PCR (MSP). RESULTS: Weak expressions of p16(INK4A) and APC in the three colon cancer cells were detected, and p21(WAF1) expression was not found in SW1116 and Colo-320 cells before treatment. After treatment of 1 micromol/L but not 10 micromol/L of 5-aza-dC, the methylation level of p16(INK4A) gene promoter decreased significantly, and the hypomethylation led to the up-regulation of p16(INK4A) gene transcription in HT-29 cells. In the cell lines of SW1116 and Colo-320, p16(INK4A) and APC mRNA expressions were obviously enhanced after treatment of either 10 micromol/L or 5 micromol/L 5-aza-dC for 24 h. However, no evidence was found that methylation regulated the expression of p21(WAF1) and c-myc genes in humancolon cancer cell lines. CONCLUSION: Expression of p16(INK4A) and APC genes is regulated by DNA methylation in three humancolon cancer cell lines.
Authors: R Abele; M Clavel; P Dodion; U Bruntsch; S Gundersen; J Smyth; J Renard; M van Glabbeke; H M Pinedo Journal: Eur J Cancer Clin Oncol Date: 1987-12
Authors: Mark W A Norrie; Nicholas J Hawkins; Alison V Todd; Alan P Meagher; Terence W O'Connor; Robyn L Ward Journal: Dis Colon Rectum Date: 2002-05 Impact factor: 4.585
Authors: J G Herman; A Merlo; L Mao; R G Lapidus; J P Issa; N E Davidson; D Sidransky; S B Baylin Journal: Cancer Res Date: 1995-10-15 Impact factor: 12.701
Authors: Ka-Fai To; Wai K Leung; Tin-Lap Lee; Jun Yu; Joanna H M Tong; Michael W Y Chan; Enders K W Ng; S C Sydney Chung; Joseph J Y Sung Journal: Int J Cancer Date: 2002-12-20 Impact factor: 7.396
Authors: Orsolya Galamb; Alexandra Kalmár; Bálint Péterfia; István Csabai; András Bodor; Dezső Ribli; Tibor Krenács; Árpád V Patai; Barnabás Wichmann; Barbara Kinga Barták; Kinga Tóth; Gábor Valcz; Sándor Spisák; Zsolt Tulassay; Béla Molnár Journal: Epigenetics Date: 2016-05-31 Impact factor: 4.528