| First Author | Tao L | Year | 2004 |
| Journal | Toxicology | Volume | 196 |
| Issue | 1-2 | Pages | 127-36 |
| PubMed ID | 15036762 | Mgi Jnum | J:90225 |
| Mgi Id | MGI:3042705 | Doi | 10.1016/j.tox.2003.11.011 |
| Citation | Tao L, et al. (2004) Hypomethylation of DNA and the insulin-like growth factor-II gene in dichloroacetic and trichloroacetic acid-promoted mouse liver tumors. Toxicology 196(1-2):127-36 |
| abstractText | Dichloroacetic acid (DCA) and trichloroacetic acid (TCA) are mouse liver carcinogens. DNA hypomethylation is a common molecular event in cancer that is induced by DCA and TCA. Hypomethylation of DNA and the insulin-like growth factor-II (IGF-II) gene was determined in DCA- and TCA-promoted liver tumors. Mouse liver tumors were initiated by N-methyl-N-nitrosourea and promoted by either DCA or TCA. By dot-blot analysis using an antibody for 5-methylcytosine, the DNA in DCA- and TCA-promoted tumors was demonstrated to be hypomethylated. The methylation status of 28 CpG sites in the differentially methylated region-2 (DMR-2) of mouse IGF-II gene was determined. In liver, 79.3 +/- 1.7% of the sites were methylated, while in DCA- and TCA-treated mice, only 46.4 +/- 2.1% and 58.0 +/- 1.7% of them were methylated and 8.7 +/- 2.6% and 10.7 +/- 7.4% were methylated in tumors. The decreased methylation found in liver from mice exposed to DCA or TCA occurred only in the upstream region of DMR-2, while in tumors it occurred throughout the probed region. mRNA expression of the IGF-II gene was increased in DCA- and TCA-promoted liver tumors but not in non-involved liver from DCA- and TCA-exposed mice. The results support the hypothesis that DNA hypomethylation is involved in the mechanism for the tumorigenicity of DCA and TCA. |
