First Author | Pignolo RJ | Year | 1995 |
Journal | J Cell Physiol | Volume | 162 |
Issue | 1 | Pages | 110-8 |
PubMed ID | 7814443 | Mgi Jnum | J:22201 |
Mgi Id | MGI:70083 | Doi | 10.1002/jcp.1041620113 |
Citation | Pignolo RJ, et al. (1995) Analysis of EPC-1 growth state-dependent expression, specificity, and conservation of related sequences. J Cell Physiol 162(1):110-8 |
abstractText | The transcript for EPC-1 (early population doubling level (PDL) cDNA-1) is induced under conditions of growth arrest due to density-dependent contact inhibition and/or serum deprivation in early-passage but not in senescent WI-38 fibroblasts. We have characterized the EPC-1 transcript with respect to its cell-cycle regulation, tissue specificity, and interspecies conservation of related genomic sequences. In low density, quiescent (serum-deprived), early-passage fibroblasts that are stimulated to proliferate with fresh serum, steady-state EPC-1 transcript levels are steadily reduced until they reach a basal level approximately 24 h after stimulation. However, when early-passage fibroblasts are made quiescent by both serum deprivation and density-dependent contact inhibition and then stimulated with serum, steady-state EPC-1 transcript levels remain relatively constant throughout a 36 h period following serum stimulation. Senescent WI-38 cells (> 95% life span completed) do not express EPC-1 under these conditions. We show that differences in the regulation of EPC-1 transcript levels in early-passage cells are due to differences in growth state rather than changes in cell density or contact. We also show that expression of the EPC-1 transcript is limited to specific cell types and that related genomic sequences are found in all mammalian species examined as well as in the chicken. |