Inhibition of fibroblast growth factor 2 expression by antisense RNA induced a loss of the transformed phenotype in a human hepatoma cell line.
Fibroblast growth factor 2 (FGF-2 or basic FGF) is associated with the cell-transformed phenotype. To clarify the function of FGF-2 in the malignancy of tumor cells, we designed experiments to express antisense RNA in a hepatoma cell line. Using FGF-2 mRNA, alternative initiations of translation at one AUG and three CUG start codons led to the synthesis of four isoforms. SK-Hep1 cells, which naturally produce the four FGF-2 proteins, were stably transfected with expression vectors that generate antisense RNAs targeted against different sites of human FGF-2 mRNA. A variable decrease of all of the isoforms of FGF-2 synthesis was observed compared with the control: the strongest inhibition was obtained with the smaller antisense targeted against AUG codon. Our results clearly demonstrated that inhibition of FGF-2 expression led to a loss of anchorage independence in soft agar. This effect was not reversed by adding exogenous FGF-2, indicating that an intracrine process of FGF-2 probably is involved in the phenotypic changes of SK-Hep1 cells. Furthermore, the inhibition of FGF-2 synthesis was correlated with a loss of tumorigenicity in nude mice. These results clearly argue for a key role of endogenous FGF-2 in transformation and tumorigenesis of the hepatoma cell line used in this study.
Maret
A
A
INSERM U397, Institut Louis Bugnard, CHU Rangueil, Toulouse, France.
Galy
B
B
Arnaud
E
E
Bayard
F
F
Prats
H
H
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002471:Cell Transformation, Neoplastic / Q000187:drug effects* / Q000235:genetics*; D016222:Fibroblast Growth Factor 2 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D010641:Phenotype; D016372:RNA, Antisense / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured
D016372:RNA, Antisense; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2