Modulation of c-fms proto-oncogene in an ovarian carcinoma cell line by a hammerhead ribozyme.
Co-expression of macrophage colony-stimulating factor (M-CSF) and its receptor (c-fms) is often found in ovarian epithelial carcinoma, suggesting the existence of autocrine regulation of cell growth by M-CSF. To block this autocrine loop, we have developed hammerhead ribozymes against c-fms mRNA. As target sites of the ribozyme, we chose the GUC sequence in codon 18 and codon 27 of c-fms mRNA. Two kinds of ribozymes were able to cleave an artificial c-fms RNA substrate in a cell-free system, although the ribozyme against codon 18 was much more efficient than that against codon 27. We next constructed an expression vector carrying a ribozyme sequence that targeted the GUC sequence in codon 18 of c-fms mRNA. It was introduced into TYK-nu cells that expressed M-CSF and its receptor. Its transfectant showed a reduced growth potential. The expression levels of c-fms protein and mRNA in the transfectant were clearly decreased with the expression of ribozyme RNA compared with that of an untransfected control or a transfectant with the vector without the ribozyme sequence. These results suggest that the ribozyme against GUC in codon 18 of c-fms mRNA is a promising tool for blocking the autocrine loop of M-CSF in ovarian epithelial carcinoma.
Yokoyama
Y
Y
Department of Obstetrics and Gynecology, Gifu University School of Medicine, Japan.
Morishita
S
S
Takahashi
Y
Y
Hashimoto
M
M
Tamaya
T
T
D001483:Base Sequence; D001665:Binding Sites; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D002822:Choriocarcinoma / Q000235:genetics / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016236:Genes, fms; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016281:Oncogene Protein gp140(v-fms) / Q000096:biosynthesis / Q000235:genetics; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism*; D000090063:Proto-Oncogene Mas; D016337:RNA, Catalytic / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
C000715470:MAS1 protein, human; D016281:Oncogene Protein gp140(v-fms); D000090063:Proto-Oncogene Mas; D016337:RNA, Catalytic; D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor