J Appl Biomed 3:193-198, 2005 | DOI: 10.32725/jab.2005.025

A morphological and cytochemical note to the reversible intranucleolar translocation of AgNORs (silver stained nucleolus organizer regions) in early leukemic granulocytic progenitors represented by cultured K 562 cells

Karel Smetana^*, Michaela Pluskalová, Ilona Jirásková, Zbyněk Hrkal

Institute of Hematology and Blood Transfusion, Prague, Czech Republic

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.

Keywords: AgNORs; intranucleolar translocation; nucleolar size; K 562 cells

Received: September 19, 2005; Published: July 31, 2005  Show citation