<p><b>BACKGROUND AND OBJECTIVE</b>The expression of TSLC1 is downregulated or abrogated in many kinds of
tumors, and its
downregulation is highly associated with
DNA hypermethlyation. The aim of this study is to explore the relationship between TSLC1 silencing and
DNA methylation of its
promoter region in
lung cancer cells.</p><p><b>
METHODS</b>We detected the expression pattern of TSLC1 in
human normal
lung tissue and three
lung cancer cell lines (A549, NCI-H446 and Calu-3) by semi-quantitative RT-PCR and
Real-time PCR. Then we detected the status of
DNA methylation in TSLC1
promoter region with bisulfite sequencing in above normal
lung tissue and
lung cancer cell lines.
After treatment of above
cell lines with the inhibitor of
DNA methyltransferase 5-Aza-2-
deoxycytidine (5-Aza-dC), we detected the expression change of TSLC1 by
Real-time PCR before and after the
treatment of 5-Aza-dC.</p><p><b>RESULTS</b>There was no
methylation in TSLC1
promoter region in normal
lung tissue and
A549 cell line in which TSLC1 expressed; while there was
DNA hypermethylation in TSLC1
promoter region in NCI-H446 and Calu-3
cell lines in which TSLC1 was abrogated, also the expression of TSLC1 in NCI-H446 and Calu-3
cell lines could be restored
after treatment of 5-Aza-dC.</p><p><b>CONCLUSION</b>The silencing of TSLC1 in
lung cancer cells is due to the hypermethylation of its
promoter region.</p>