AUTHOR=Giebler Maria , Greither Thomas , Behre Hermann M. 

TITLE=Differential Regulation of PIWI-LIKE 2 Expression in Primordial Germ Cell Tumor Cell Lines by Promoter Methylation

JOURNAL=Frontiers in Genetics

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2018.00375

DOI=10.3389/fgene.2018.00375

ISSN=1664-8021

ABSTRACT=<p><italic>PIWI-LIKE 2</italic>, a member of the ARGONAUTE protein family, is exclusively expressed in pre-pachytene and pachytene stages of spermatogenesis. <italic>PIWI-LIKE 2</italic> acts in the germ cell development and the silencing of retrotransponsons to maintain the genomic integrity and stem cell character. In the present study we investigated DNA methylation as potential mechanism for the regulation of human <italic>PIWI-LIKE 2</italic> expression in cell lines related to spermatozoa precursor cells. We detected a high methylation of the <italic>PIWI-LIKE 2</italic> promoter in TCam-2 cells, while in NT2/D1 cells the promoter was hypomethylated. Concordantly, <italic>PIWI-LIKE 2</italic> expression is higher in NT2/D1 cells than in TCam-2 cells. By demethylation of the promoter with 5′-Aza-2′-deoxycytidine, <italic>PIWI-LIKE 2</italic> expression in TCam-2 was increased, while in NT2/D1 no alterations in <italic>PIWI-LIKE 2</italic> expression could be detected. In conclusion, we analyzed the DNA methylation driving <italic>PIWI-LIKE 2</italic> expression in undifferentiated germ cell tumors and demonstrated an epigenetic basis for <italic>PIWI-LIKE 2</italic> expression in this cell type.</p>