Down-regulation of human FEN-1 gene expression during differentiation of promyelocytic leukemia cells.
- Author:
In Sook KIM
1
Author Information
1. Department of Natural Sciences Chemistry Section, Catholic University of Korea College of Medicine, Seoul, Korea. ikim@cmc.cuk.ac.kr
- Publication Type:Original Article
- Keywords:
Cell differentiation;
FEN-1;
Gene expression;
HL-60 cells
- MeSH:
3T3 Cells;
Animal;
Blotting, Western;
Cell Cycle/genetics;
Cell Differentiation;
Cell Division/genetics*;
Dimethyl Sulfoxide/pharmacology;
Down-Regulation (Physiology);
Endodeoxyribonucleases/genetics*;
Flow Cytometry;
Gene Expression Regulation, Neoplastic*;
HL-60 Cells;
Human;
Leukemia, Promyelocytic, Acute/genetics*;
Mice
- From:Experimental & Molecular Medicine
1998;30(4):252-256
- CountryRepublic of Korea
- Language:English
-
Abstract:
Flap endo/exonuclease-1 (FEN-1) recognizes 5'-flap DNA structures that have been proposed to be important intermediates in DNA replication, repair and recombination, and cleaves the double strand-single strand junction of flap substrates. Using an in vitro model system, recent studies have shown that FEN-1 is a necessary enzyme for the removal of RNA primers in Okazaki fragment maturation during lagging strand DNA synthesis. In this report, the FEN-1 gene expression was examined during cell cycle and differentiation. Although FEN-1 mRNA and protein could be detected at all stages of the cell cycle, their levels were more elevated in exponentially proliferating cells than in G1 or G2/M-synchronized cells. Moreover, a significant increase of FEN-1 protein was observed when temporarily quiescent fibroblasts were induced to proliferate by serum stimulation. In contrast, the FEN-1 mRNA level showed a sharp decrease in HL-60 cells differentiated by dimethyl-sulfoxide, all-trans retinoic acid or 12-O-tetradecanoylphorbol-13-acetate. These results demonstrate that the FEN-1 gene expression is up-regulated during entrance into the mitotic cell cycle and down-regulated in nongrowing cells, as in the case of differentiated promyelocytic leukemia cells.
