Transcriptional repression of the transforming growth factor-β type I receptor gene by DNA methylation results in the development of TGF-β resistance in human gastric cancer
Transcriptional repression of the transforming growth factor-β type I receptor gene by DNA methylation results in the development of TGF-β resistance in human gastric cancer
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DOI：
10.1038/sj.onc.1203146
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发表时间：
1999-12-02
期刊：
影响因子：
8
通讯作者：
Kim, SJ
中科院分区：
文献类型：
--
作者：
Kang, SH;Bang, YJ;Kim, SJ
The transforming growth factor-beta (TGF-beta) signaling pathway subserves an essential tumor suppressor function in various cell types. A heteromeric complex composed of TGF-beta type I (RI) and type II (RII) receptors is required for TGF-beta signaling. We have identified a subset of human gastric cancer cell lines which are insensitive to TGF-beta and which express a low level of TGF-beta type I receptor mRNA relative to a gastric cancer cell line which is highly responsive to TGF-beta. Using these cells, we show that hypermethylation of a CpG island in the 5' region of the TGF-beta RI gene provides another potentially important mechanism of escape from negative growth control by TGF-beta, This hypermethylation was found in four of five human gastric cancer cell lines and five out of 40 (12.5%) primary tumors examined, In human gastric cancer cell lines, treatment with the demethylating agent, 5-aza-2'-deoxycytidine, resulted in increased expression of the TGF-beta RI gene, but not the RII gene, Transient transfection of an RI expression vector into the TGF-beta resistant SNU-601 cell line restores TGF-beta responsiveness. These findings suggest that one of the mechanisms of escape from autocrine or paracrine growth control by TGF-beta during carcinogenesis could involve aberrant methylation of CpG islands in the 5' region of the TGF-beta RI gene.
