Tritiated actinomycin-D staining method: a valuable tool to study oestrogen receptor-induced modifications of transcriptional activity in normal and neoplastic cells.
Exposure at 4 degrees C of purified cell nuclei from uterus and hormone-sensitive mammary cancer to their own cytosol preincubated with oestradiol produced a significant increase in their ability to bind [3H] actinomycin D (3H-AMD). This increase did not occur under conditions preventing the transfer of the oestrogen-receptor into the cell nucleus, nor in cancer cell nuclei devoid of oestrogen-receptors. Uterine cytosol preincubated with the strong antioestrogen 4-hydroxytamoxifen did not modify the 3H-AMD binding capacity of the uterine nuclei but significantly suppressed the increase induced by oestradiol. Moreover, ultrastructural study of tumour nuclei revealed that the oestradiol receptor-induced increase was associated with a marked chromatin dispersion. These results strongly suggest that the 3H-AMD staining method is a valuable tool for the assessment of oestrogen receptor-induced modifications of transcriptional activity in normal and pathological tissue as well.
A
A
Verrijdt
G
G
Leclercq
N
N
Devleeschouwer
A
A
Danguy
D000818:Animals; D001345:Autoradiography; D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D003609:Dactinomycin / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism*; D051379:Mice; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains; D011960:Receptors, Estrogen / Q000378:metabolism*; D014158:Transcription, Genetic; D014316:Tritium; D014599:Uterus / Q000378:metabolism*
D011960:Receptors, Estrogen; D014316:Tritium; D003609:Dactinomycin; D004958:Estradiol