Corresponding Author:
Sang Jin Kim ,Tel: +82-41-570-3672, Fax: +82-41-574-5762, Email: ksj1113@schmc.ac.kr
ABSTRACT
Gelsolin is an actin-binding protein involved in dynamic changes of the actin cytoskeleton. The protein regulates the length of actin
filaments by binding, severing, and capping the fast-growing filament ends and promotes actin nucleation. Gelsolin is widely expressed
in normal tussues. Decreased gelsolin expression occurs in many transformed cell types and in carcinomas of the colon,
bladder, breast, lung, stomach, and prostate. Transciptional silencing of tumor suppressor genes by aberrant methylation of CpG islands
plays a crucial role in the development of various cancers. Noske et al. showed inactivation of gelsolin might be mediated by
epigenetic modification. But there is no information about the relationship between the gelsolin gene and thyroid cancer. We investigated
DNA methylation in thyroid cancer cell lines and tissues from papillary thyroid cancer. We performed reverse transcription-
polymerases chain reaction with methylation inhibitor 5-aza-2’-deoxycytidine (DAC) treatment and histone deacetylase inhibitor
trichostatin A (TSA) treatment in 3 thyroid cancer cell lines, and combined bisulfite restriction analysis in 5 thyroid cancer cell
lines and thyroid tissues from 12 papillary thyroid cancers. Almost all thyroid cancer cell lines showed promoter hypermethylation
of gelsolin. Gelsolin was not methylated in all of 12 papillary thyroid cancer tissue specimens. DAC and TSA treatment did not increase
the expression of gelsolin messenger RNA in thyroid cancer cell lines. These results suggest that DNA methylation of gelsolin
does not contribute to thyroid tumor development, especially in papillary thyroid carcinoma.