Possible role of DNA topoisomerase II on transcription of the homeobox gene Hox-2.1 in F9 embryonal carcinoma cells.
The Hox-2.1 gene is one of homeobox-containing genes located in the Hox-2 cluster on mouse chromosome 11. In this study, we have examined transcription of the Hox-2.1 gene during differentiation of F9 embryonal carcinoma cells induced by treatment with retinoic acid. The level of Hox-2.1 mRNA increases rapidly after induction of differentiation and then falls. Nuclear run-on experiments demonstrate that the rate of transcription for the Hox-2.1 gene also increases upon differentiation. Treatment of F9 cells with a DNA topoisomerase II inhibitor etoposide (VP-16) during differentiation blocks the accumulation of Hox-2.1 mRNA. Nuclear run-on analyses reveal that etoposide inhibits transcription of the Hox-2.1 gene during F9 cell differentiation. Measurements of the level of Hox-2.1 mRNA after blocking transcription by actinomycin D show that etoposide does not affect stability of the mRNA. These observations indicate that DNA topoisomerase II is involved in the control of Hox-2.1 gene transcription.
Ura
K
K
DNA Research Center, National Institute of Genetics, Mishima, Japan.
Hirose
S
S
D015152:Blotting, Northern; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004273:DNA, Neoplasm / Q000235:genetics; D054278:Embryonal Carcinoma Stem Cells; D005047:Etoposide / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D005801:Genes, Homeobox; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics; D014158:Transcription, Genetic
D004273:DNA, Neoplasm; D012333:RNA, Messenger; D005047:Etoposide; D004250:DNA Topoisomerases, Type II