Acidic FGF and EGF are involved in the autocrine growth stimulation of a human nasopharyngeal carcinoma cell line and sub-line cells.
The growth of a recently established human nasopharyngeal carcinoma cell line, CG-1, and 5 randomly selected, single-cell-derived sub-lines in serum-free medium and in fetal-bovine-serum(FBS)-containing medium was investigated. In basal medium supplemented with insulin, transferrin, fibronectin and high-density lipoprotein, cell growth was moderately stimulated by aFGF and EGF in a dose-dependent manner. In contrast, in medium containing as little as 0.5% FBS, most of the stimulatory effect of the aforementioned growth factors observed was masked. Western blotting analysis of the cell lysates and conditioned media showed that CG-1 and sub-line cells were all capable of synthesizing and releasing aFGF- and EGF-immunoreactive proteins. The amounts of these 2 growth factors synthesized and released appeared to vary among the parental cell line and sub-line cells. Moreover, the rate of basal proliferation of these cells appeared to be positively correlated with the amounts of aFGF- and EGF-immunoreactive proteins produced. Addition of the neutralizing antibodies to aFGF and EGF exerted a dose-dependent suppression on cell growth in medium containing 0.5% FBS. The results suggest a role of aFGF and EGF in autocrine growth stimulation of CG-1 and sub-line cells, and may explain the moderate response of these cells to exogenously added aFGF and EGF.
Chao
H H
HH
Department of Biology, Tunghai University, Taichung, Taiwan.
Yang
V C
VC
Chen
J K
JK
D002277:Carcinoma / Q000378:metabolism / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D016895:Culture Media, Serum-Free; D004305:Dose-Response Relationship, Drug; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D016220:Fibroblast Growth Factor 1 / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured
D016895:Culture Media, Serum-Free; D016220:Fibroblast Growth Factor 1; D004815:Epidermal Growth Factor