Open AccessTCF 21 hypermethylation regulates renal tumor cell clonogenic proliferation and migration
Author(s) -
Gooskens Saskia L.,
Klasson Timothy D.,
Gremmels Hendrik,
Logister Ive,
Pieters Robert,
Perlman Elizabeth J.,
Giles Rachel H.,
van den HeuvelEibrink Mary M.
Publication year - 2018
Publication title -
molecular oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.332
H-Index - 88
eISSN - 1878-0261
pISSN - 1574-7891
DOI - 10.1002/1878-0261.12149
Subject(s) - ectopic expression , biology , transcription factor , dna methylation , downregulation and upregulation , cancer research , transfection , mesenchymal stem cell , clear cell renal cell carcinoma , methylation , cell , cell growth , clonogenic assay , microbiology and biotechnology , cell culture , gene expression , gene , pathology , renal cell carcinoma , medicine , genetics
We recently identified hypermethylation at the gene promoter of transcription factor 21 ( TCF 21 ) in clear cell sarcoma of the kidney ( CCSK ), a rare pediatric renal tumor. TCF 21 is a transcription factor involved in tubular epithelial development of the kidney and is a candidate tumor suppressor. As there are no in vitro models of CCSK , we employed a well‐established clear cell renal cell carcinoma (cc RCC ) cell line, 786‐O, which also manifests high methylation at the TCF 21 promoter, with consequent low TCF 21 expression. The tumor suppressor function of TCF 21 has not been functionally addressed in cc RCC cells; we aimed to explore the functional potential of TCF 21 expression in cc RCC cells in vitro . 786‐O clones stably transfected with either pBABE ‐ TCF 21‐ HA construct or pBABE vector alone were functionally analyzed. We found that ectopic expression of TCF 21 in 786‐O cells results in a trend toward decreased cell proliferation (not significant) and significantly decreased migration compared with mock‐transfected 786‐O cells. Although the number of colonies established in colony formation assays was not different between 786‐O clones, colony size was significantly reduced in 786‐O cells expressing TCF 21 . To investigate whether the changes in migration were due to epithelial‐to‐mesenchymal transition changes, we interrogated the expression of selected epithelial and mesenchymal markers. Although we observed upregulation of mRNA and protein levels of epithelial marker E‐cadherin in clones overexpressing TCF 21 , this did not result in surface expression of E‐cadherin as measured by fluorescence‐activated cell sorting and immunofluorescence. Furthermore, mRNA expression of the mesenchymal markers vimentin ( VIM ) and SNAI 1 was not significantly decreased in TCF 21 ‐expressing 786‐O cells, while protein levels of VIM were markedly decreased. We conclude that re‐expression of TCF 21 in renal cancer cells that have silenced their endogenous TCF 21 locus through hypermethylation results in reduced clonogenic proliferation, reduced migration, and reduced mesenchymal‐like characteristics, suggesting a tumor suppressor function for transcription factor 21.