In vitro changes of the nuclear AgNORs pattern induced by RNA inhibitors and 5-fluorouracil in human breast cancer cells, MCF-7 and HBC-4.
The morphological changes of argyrophilic nucleolar organizer regions (AgNORs) were studied in two human breast cancer cell lines, MCF-7 and HBC-4. Treatment with an RNA polymerase inhibitor (actinomycin D) reduced the size of AgNORs and increased the number of AgNORs. Messenger RNA polymerase inhibitor (alpha-amanitin) also increased the number of AgNORs. However, translational blocking agents closely related to ribosomal RNA (cycloheximide and anisomycin) caused a decrease in the number of AgNORs, which seemed to fuse to an aggregate around the nucleolus and formed a single large spherical AgNOR in the final stage. These changes were observed typically when cells were treated with 5-fluorouracil or 5-fluorouridine. These morphological changes in the AgNORs pattern, AgNORs aggregation, might reflect certain damage in ribosomal RNA.
Furuya
Y
Y
First Department of Surgery, Kobe University School of Medicine, Japan.
Yamamoto
K
K
Kohno
N
N
Hamaoka
T
T
Ono
H
H
Kuroda
Y
Y
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D002452:Cell Count / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology; D005472:Fluorouracil / Q000494:pharmacology*; D006801:Humans; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology*; D009697:Nucleolus Organizer Region / Q000187:drug effects* / Q000378:metabolism; D016622:Silver Staining; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
D000964:Antimetabolites, Antineoplastic; D019384:Nucleic Acid Synthesis Inhibitors; D003609:Dactinomycin; D005472:Fluorouracil