The present study was undertaken to provide more information on the nucleolar size, number and distribution of AgNORs (silver stained nucleolus organizer regions) in nucleolar bodies of aging leukemic granulocytic progenitor cells represented by cultured K562 cells. In these aging and starving cells without further differentiation and with translocated AgNORs to the nucleolar periphery, the diameter of the nucleolar size was reduced together with a reduction in the number of these nucleolar compartments. However, after re-feeding cell cultures, the nucleolar size increased again. Similarly, the number of AgNORs also increased and was distributed in the whole nucleolar body as in control cells. Such cells apparently entered into the cycle and proliferation documented by the re-occurrence of mitotic divisions in studied cultures, an increased number of AgNORs and increased nuclear size. This observation suggests that early granulocytic precursors with translocated nucleolar AgNORs might represent a transitionally quiescent population of cells which may return to a fully proliferating state.
AgNORs; intranucleolar translocation; nucleolar size; K 562 cells
Busch H, Smetana K: The Nucleolus. Academic Press, New York 1970, pp. xvi+626.
Gonzalez P, Nardone RM: Cyclic nucleolar changes during the cell cycle. Exp Cell Res 50:599-615, 1968.
Derenzini M: The AgNORs. Micron 31:117-120, 2000.
Derenzini M, Farabegoli F, Trere D: Relationship between interphase AgNOR distribution and nucleolar size in cancer cells. Histochem J 24:951-956, 1992.
Lozzio BB, Lozzio CB, Feliu AS: A multipotential leukemia cell line (K 562) of human origin. Proc Soc Exp Biiol Med 166:546-550, 1981.
Ochs RL: Methods used to study structure and function of the nucleolus. Methods Cell Biol 53:303-321, 1998.
Ploton D, Beorchia A, Menager M et al.: The three - dimensional ultrastructure of interphasic and metaphasic nucleolar argyrophilic components studied with high voltage electron microscopy in thick sections. Biol Cell 59:113-120, 1987.
Schnedl W, Schnedl M: Nukleoluszahl und grosse wahrend des zellzyklus. Z Zellforsch Mikrosk Anat 126:374-382, 1972.
Smetana K: Nucleoli in blood cells of hematologic malignancies: structure, cytochemistry of nucleoli in leukemic, lymphoma and myeloma cells. In: Romero RM (ed.): Trends in Leukemia Research, Nova Science Publishers, New York 2005.
Smetana K, Cajthanmlova H, Grebenova D, Hrkal Z: The 5-aminolaevulinic acid-based photodynamic effects on nucleoli and nuclei of HL-60 leukemic granulocytic precursors. J Photochem Photobiol B 59:80-86, 2000.
Smetana K, Jiraskova I, Perlaky L, Busch H: The silver reaction of nucleolar proteins in the main structural compartments of ring shaped nucleoli in smear preparations. Acta Histochem 101:167-183, 1999.
Smetana K, Klamova H, Pluskalova M et al.: Intranucleolar translocation of AgNORs in early granulocytic precursors in chronic myeloid leukaemia and K 562 cells. Folia Biol (Praha) 51:89-92, 2005a.
Smetana K, Klamova H, Pluskalova M at al.: To the intranucleolar translocation of AgNORs in leukemic early granulocytic and plasmacytic precursors. Histochem Cell Biol s00418-005-0059-z (on line), the printed edition - in press, 2005b.
Smetana K, Lejnar H, Potmesil M: A further contribution to the demonstration of RNA and nucleoli of blood cells in smear preparations. Folia Haematol 91:381-384, 1969.
Trere D, Pession A, Derenzini M: The silverstained proteins of interphasic nucleolar organizer regions as a parameter of cell duplication rate. Exp Cell Res 184:131-137, 1989.
Smetana K. The nucleolus through the years. J Appl Biomed. 9: 119-127, 2011.
Smetana K, Jiraskova I, Mikulenkova D, Klamova H. The translocation of AgNORs in large nucleoli of early granulocyte progenitors in patients suffering from chronic phase of chronic myeloid leukaemia. J Appl Biomed. 7: 111-114, 2009.
Smetana K, Mikulenkova D, Jiraskova I, Klamova H. A karyometric note on nucleoli in human early granulocytic precursors. Folia Biol. 52: 16-20, 2006.