Expression of insulin-like growth factor-IA and factor-IB mRNA in human liver, hepatoma cells, macrophage-like cells and fibroblasts.
The human insulin-like growth factor-I (IGF-I) gene codes for two transcripts, IGF-IA and IGF-IB mRNAs, formed by alternative splicing. In this study, the expression of these IGF-I mRNA transcripts was examined using human liver, hepatoma cells, macrophage-like cells and fibroblasts. The reverse transcription-polymerase chain reaction revealed that these cells contained both IGF-IA mRNA (representing exons I, II, III and V) and IGF-IB mRNA (representing exons I, II, III and IV). Interestingly, an RNase protection assay using 32P-labeled IGF-IA and IGF-IB exon-specific cRNA probes demonstrated that IGF-IA mRNA was 10-fold more abundant than IGF-IB mRNA in these cells. However, there was no difference in the stabilities of IGF-IA and IGF-IB mRNAs. These observations indicate that IGF-IA mRNA is more expressed than IGF-IB mRNA in these cells independent of their stabilities.
Nagaoka
I
I
Department of Biochemistry, Juntendo University, School of Medicine, Tokyo, Japan.
Someya
A
A
Iwabuchi
K
K
Yamashita
T
T
D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D002460:Cell Line; D015342:DNA Probes; D005091:Exons; D005347:Fibroblasts / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics*; D008099:Liver / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D012333:RNA, Messenger / Q000096:biosynthesis*; D012260:Ribonucleases; D014158:Transcription, Genetic
D015342:DNA Probes; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D012260:Ribonucleases