Cloning of cDNA with possible transcription factor activity at the G1-S phase transition in human fibroblast cell lines.
Normal human fibroblasts have a finite proliferative capacity in vitro. Thus, immortalization of human cells is associated with cellular aging. We have established an immortalization-sensitive cell line from fibroblasts of Wilms' tumor patients which have a partial deletion of chromosome 1 1p. This cell line was easily immortalized by introducing SV4OT. By differential hybridization using both SV4OT-introduced crisis cells and young cells, we cloned a gene that was highly expressed in 1 1p-cells at the time of the crisis and named this gene C-1. Nucleotide sequence analysis of C-1 revealed that it contains a helix-loop-helix domain, indicating that it may be a transcription factor. Expression of the C-1 gene was transiently induced early in the G0-to-S phase transition in two normal human (OUMS-24 and HSF-412) and a non-tumorigenic immortal human (OUMS-24F) fibroblast cell lines, while the other immortal SUSM-1 cells highly expressed the C-1 gene in the middle G1 phase. These results suggest that the C-1 gene product may function as a transcription factor related to the cell cycle.
Iijima
M
M
Department of Cell Biology, Okayama University Medical School, Japan.
Kano
Y
Y
Nohno
T
T
Namba
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle; D002460:Cell Line; D002872:Chromosome Deletion; D002880:Chromosomes, Human, Pair 11; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005786:Gene Expression Regulation; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012333:RNA, Messenger / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*
D018076:DNA, Complementary; D012333:RNA, Messenger; D014157:Transcription Factors