TET1-mediated DNA hypomethylation regulates the expression of MUC4 in lung cancer.

Lung cancer remains a disease of high mortality, despite advanced diagnostic techniques. Mucins (MUC) play crucial roles in carcinogenesis and tumor invasion in lung neoplasms. Our immunohistochemistry (IHC) studies have shown that high MUC4 expression correlates with a poor outcome. We have also shown that the expression of several mucin genes in cancer cell lines is regulated by DNA methylation. We evaluated the expression level of MUC4, mRNA and several DNA hypomethylation factors in lung tissue samples from 33 patients with various lung lesions. The results indicated that the DNA methylation status of matched the expression level of mRNA. In addition, the (Ten-Eleven Translocation) mRNA showed a significant correlation with the status of DNA methylation of . Furthermore, the treatment of a lung cancer cell line with siRNA caused a reduction in mRNA expression. Thus, we suggest that mediated DNA hypomethylation plays a key role in the expression of MUC4. This is the first report that TET1 mediated DNA hypomethylation regulates the expression of MUC4 in lung cancer. The analysis of these epigenetic changes may be useful for diagnosing carcinogenic risk.