title: Differential inhibition of telomerase activity during induction of differentiation in hematopoietic, melanoma, and glioma cells in culture.
abstract: Accumulating evidence indicates that telomerase activity is stringently repressed in normal human somatic cells but reactivated in cancers and immortal cells, suggesting that activation of telomerase activity may play a role in carcinogenesis and immortalization. Recently, down-regulation of telomerase activity by induction of differentiation has been reported for cells of pre-myelocytic and myelocytic leukemia as well as embryonic carcinoma. To gain further insight about the regulation of telomerase activity following induction of differentiation, telomerase activity was examined in a human hematopoietic progenitor cell line (D2), a melanoma cell line (CM73-36) and a glioma cell line (Ast812) before and after addition of differentiation inducing agents. The state of differentiation was assessed by growth inhibition and cell morphological maturation. Telomerase activity was assayed by a PCR-based telomeric repeat amplification protocol (TRAP). Our data show that telomerase activity was inhibited only in differentiation-induced D2 cells but not in differentiation-induced melanoma and glioma cells. A model for the differential inhibition of telomerase activity following induction of differentiation in different cancer cells will be presented.
authors.affiliation: Department of Molecular Biology, Chang Gung College of Medicine and Technology, Tao-Yuan, 333, Taiwan.
authors.forename: A J
authors.initials: AJ
authors.lastname: Cheng
authors.forename: S K
authors.initials: SK
authors.lastname: Liao
authors.forename: S E
authors.initials: SE
authors.lastname: Chow
authors.forename: J K
authors.initials: JK
authors.lastname: Chen
authors.forename: T C
authors.initials: TC
authors.lastname: Wang
mesh_terms: D001932:Brain Neoplasms / Q000201:enzymology* / Q000473:pathology; D002454:Cell Differentiation; D005910:Glioma / Q000201:enzymology* / Q000473:pathology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000201:enzymology*; D006801:Humans; D008545:Melanoma / Q000201:enzymology* / Q000473:pathology; D019098:Telomerase / Q000037:antagonists & inhibitors*; D014407:Tumor Cells, Cultured
chemical_list: D019098:Telomerase