title: In situ fluorescent visualization of nucleolar organizer region-associated proteins with a thiol reagent.
abstract: Nucleolar organizer regions (NORs) are nucleolus-forming rDNA loops associated with argyrophil proteins, the amount of which varies according to the proliferative state of the cell. It has been presumed that the nucleolar protein-related thiol groups may have a role in selective silver staining. We investigated the nuclear thiol distribution with a fluorescent thiol reagent, coumarinyl-phenyl-maleimide (CPM) in human K-562 myeloblast cultures and found that SH group-related fluorescence was brightest in the area of nucleoli, which became highly selective after RNAse digestion. A remarkable co-localization of AgNOR silver reaction and CPM fluorescence was observed, although occupation of the SH groups by CPM did not prevent the silver staining. We applied the stain to dual-parameter flow cytometry in combination with DNA content measurements, which provide further information on nucleolar function and changes in experimental and pathological specimens.
authors.affiliation: Department of Pathology, University Medical School of Pécs, Hungary.
authors.forename: G
authors.initials: G
authors.lastname: Méhes
authors.forename: E
authors.initials: E
authors.lastname: Kálmán
authors.forename: L
authors.initials: L
authors.lastname: Pajor
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D002478:Cells, Cultured; D004247:DNA / Q000032:analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007938:Leukemia / Q000378:metabolism / Q000473:pathology; D008198:Lymph Nodes / Q000737:chemistry / Q000166:cytology / Q000648:ultrastructure; D008223:Lymphoma / Q000737:chemistry / Q000473:pathology / Q000648:ultrastructure; D008856:Microscopy, Fluorescence; D009687:Nuclear Proteins / Q000032:analysis* / Q000378:metabolism; D009697:Nucleolus Organizer Region / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D012834:Silver; D013438:Sulfhydryl Compounds; D014407:Tumor Cells, Cultured
chemical_list: D004273:DNA, Neoplasm; D009687:Nuclear Proteins; D013438:Sulfhydryl Compounds; D012834:Silver; D004247:DNA