TY - JOUR
T1 - Modulation of cell growth and transformation by doxycycline-regulated FGF-2 expression in NIH-3T3 cells
AU - Gualandris, Anna
AU - Arese, Marco
AU - Shen, Bin
AU - Rifkin, Daniel B.
PY - 1999
Y1 - 1999
N2 - The single-copy fibroblast growth factor 2 (FGF-2) gene encodes four coexpressed isoforms of different molecular masses. The 18-kDa FGF-2 is primarily localized in the cytoplasm, whereas the higher molecular mass isoforms (HMW FGF-2) localize to the nucleus and nucleolus. The overexpression of either 18-kDa FGF-2 or HMW FGF-2 promotes cell transformation in a dose-dependent manner, in NIH 3T3 cells, the selective overexpression of HMW FGF-2 but not of 18-kDa FGF-2 confers upon the cells the unique phenotype of growth in low serum-containing medium. Thus, the distinct intracellular localization and the level of expression of FGF-2 are pivotal requirements for the differential effects of FGF-2 isoforms on the cellular phenotype. On this basis, we established a doxycycline-regulatable FGF-2 expression system that permitted us to regulate the expression of each isoform in a time- and dose-dependent manner. We analyzed the growth properties of cells in the presence and absence of doxycycline in both normal and low serum-containing medium and in soft agar. The doxycycline-activated expression of 18-kDa FGF-2 did not allow growth in low serum medium. The growth of cells expressing HMW FGF-2 was increased by doxycycline under all three conditions, and a relationship between the level of HMW FGF-2 expression and cell growth was observed for all three conditions. This doxycycline-regulatable FGF-2 expression system provides a mechanism to analyze changes in FGF-2 targeted pathways and genes and to characterize pathways specifically activated by either the 18-kDa FGF-2 or the HMW FGF-2 isoforms.
AB - The single-copy fibroblast growth factor 2 (FGF-2) gene encodes four coexpressed isoforms of different molecular masses. The 18-kDa FGF-2 is primarily localized in the cytoplasm, whereas the higher molecular mass isoforms (HMW FGF-2) localize to the nucleus and nucleolus. The overexpression of either 18-kDa FGF-2 or HMW FGF-2 promotes cell transformation in a dose-dependent manner, in NIH 3T3 cells, the selective overexpression of HMW FGF-2 but not of 18-kDa FGF-2 confers upon the cells the unique phenotype of growth in low serum-containing medium. Thus, the distinct intracellular localization and the level of expression of FGF-2 are pivotal requirements for the differential effects of FGF-2 isoforms on the cellular phenotype. On this basis, we established a doxycycline-regulatable FGF-2 expression system that permitted us to regulate the expression of each isoform in a time- and dose-dependent manner. We analyzed the growth properties of cells in the presence and absence of doxycycline in both normal and low serum-containing medium and in soft agar. The doxycycline-activated expression of 18-kDa FGF-2 did not allow growth in low serum medium. The growth of cells expressing HMW FGF-2 was increased by doxycycline under all three conditions, and a relationship between the level of HMW FGF-2 expression and cell growth was observed for all three conditions. This doxycycline-regulatable FGF-2 expression system provides a mechanism to analyze changes in FGF-2 targeted pathways and genes and to characterize pathways specifically activated by either the 18-kDa FGF-2 or the HMW FGF-2 isoforms.
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U2 - 10.1002/(SICI)1097-4652(199911)181:2<273::AID-JCP9>3.0.CO;2-#
DO - 10.1002/(SICI)1097-4652(199911)181:2<273::AID-JCP9>3.0.CO;2-#
M3 - Article
C2 - 10497306
VL - 181
SP - 273
EP - 284
JO - Journal of cellular and comparative physiology
JF - Journal of cellular and comparative physiology
SN - 0021-9541
IS - 2
ER -