Promoter methylation of gelsolin gene in thyroid cancer
Sangjin Kim, Mio Rho, Changhee Chung, Yeojoo Kim, Chulhee Kim, Dongwon Byun, Kyoil Seo & Myunghee Yoo
Gelsolin is an actin-binding protein involved in dynamic changes of the actin cytoskeleton. This 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 tissues. Decreased gelsolin expression occurs in many transformed cell types and in carcinomas of the colon, bladder, breast, lung, stomach and prostate. Transcriptional 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 RT-polymerases chain reaction (RT-PCR) with methylation inhibitor 5-aza-2′-deoxycytidine (DAC) treatment and histone deacetylase inhibitor trichostatin (TSA) in 3 thyroid cancer cell lines, and combined bisulfite restriction analysis (COBRA) in 10 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 mRNA in thyroid cancer cell lines. These results suggest that DNA methylation of gelsolin do not contribute to thyroid tumor development, especially in papillary thyroid carcinoma.