Targeted inhibition of the transcription factor YY1 in an embryonal carcinoma cell line results in retarded cell growth, elevated levels of p53 but no increase in apoptotic cell death.
The ubiquitous cellular transcription factor Yin Yang-1 (YY1) is involved in the transcriptional regulation of many cellular and viral genes. It is known to bind to, and repress the activity of, the major immediate-early promoter of human cytomegalovirus (HCMV) in non-permissive T2 cells. Thus, YY1 is at least partly responsible for the lack of productive lytic infection of these cells. In this study, we have used short interfering RNA (siRNA) to specifically knock down YY1 expression in T2 cells. We wished to assess whether the removal of this negatively acting factor would render these ordinarily non-permissive cells permissive for infection. We show that we can potently inhibit YY1 expression but that this knock down has dramatic effects on the normal biology of the cells. In particular, we noted growth retardation, altered morphology and increased levels of p53. However, the cells do not undergo apoptosis, are not induced to differentiate, do not exhibit excessive levels of DNA damage, and synthesise DNA normally.
Bain
Mark
M
Department of Medicine, University of Cambridge, PO Box 157, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK. mb231@mole.bio.cam.ac.uk
Sinclair
John
J
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002277:Carcinoma / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D006801:Humans; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D050986:YY1 Transcription Factor
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D034741:RNA, Small Interfering; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D050986:YY1 Transcription Factor; C494698:YY1 protein, human