Cell cycle dependent distribution of proliferating cell nuclear antigen/cyclin and cdc2-kinase in mouse T-lymphoma cells.

Abstract

The aim of the present study was to investigate bromodeoxyuridine (BrdU) uptake and coordinated distribution of proliferating cell nuclear antigen (PCNA) and p34-cdc2-kinase, two important proteins involved in cell cycle regulation and progression. Flow cytometric analysis of marker proteins in freshly plated mouse T-lymphoma cells (Yac-1 cells), using fluorescein isothiocyanate (FITC)-labeled specific antibodies, showed PCNA distributed throughout the cell cycle with increased intensity in S-phase. PCNA is essential for cells to cycle through S-phase and its synthesis is initiated during late G1-phase before incorporation of BrdU and remains high during active DNA replication. The intensity of PCNA fluorescence increases with the duration of incubation after plating. The cdc2-kinase was detectable in all phases of the cell cycle and the G2-M-phase appears to have the maximum concentrations. The cell cycle analysis of high dose colcemid (2 micrograms/ml) treated Yac-1 cells showed an aneuploid or hypodiploid population. Although the G2-M-phase seems to be the dominating population in aneuploid cells, the concentrations of cdc2-kinase were variable in this phase of cell cycle. The colcemid treatment at 25 ng/ml arrested 96% of cells in S-phase and G2-M-phase, but PCNA expression was evident in a portion of the cell population in G2-M-phase. Although cells blocked in M-phase seem to have high levels of cdc2-kinase, colcemid renders them inactive. From these data, it appears that the down regulation and/or inactivation of cdc2-kinase could be responsible for the colcemid arrest of cells in M-phase.

• Authors: D A Brott, J D Alvey, M R Bleavins, F A de la Iglesia, N D Lalwani
• Journal: Journal of cellular biochemistry (J Cell Biochem) Vol. 52 Issue 3 Pg. 362-72 (Jul 1993) ISSN: 0730-2312 [Print] United States
• PMID: 8103524 (Publication Type: Journal Article)

Chemical References

• Antigens, Neoplasm
• Nuclear Proteins
• Proliferating Cell Nuclear Antigen
• CDC2 Protein Kinase
• Bromodeoxyuridine

Topics

• Animals
• Antigens, Neoplasm (metabolism)
• Bromodeoxyuridine (metabolism)
• CDC2 Protein Kinase (metabolism)
• Cell Cycle (physiology)
• Cell Division (physiology)
• Lymphoma, T-Cell (enzymology, metabolism, pathology)
• Mice
• Mitosis (physiology)
• Nuclear Proteins (metabolism)
• Proliferating Cell Nuclear Antigen
• Tumor Cells, Cultured