Chronic exposure to dexamethasone induces hypomethylation of ornithine decarboxylase genes in a human myeloma cell line

FEBS Letters

Jänne, Juhani²  Jänne, Olli A.¹  Laine, Raija²  Alhonen-Hongisto, Leena²  Leinonen, Pekka² 

[1] The Population Council and the Rockefeller University, New York, NY 10021, USA;Department of Biochemistry, University of Helsinki, SF-00170 Helsinki, Finland

关键词: Dexamethasone;    Ornithine decarboxylase;    Gene methylation;    mRNA;    (Sultan myeloma);   

DOI  :  10.1016/0014-5793(87)80115-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Chronic exposure of a human myeloma cell line to dexamethasone resulted in a selection of cells resistant to the growth-inhibitory action of the glucocorticoid. Upon acute exposure of the parental myeloma cells to dexamethasone growth inhibition was associated with depression of ornithine decarboxylase (ODC, EC 4.1.1.17) activity. However, in cells adapted to grow in the presence of micromolar concentrations of dexamethasone, ODC activity was fully comparable to that in the parental cells. Restriction enzyme analyses with the two isoschizomers HpaII and MspI as well as with the methylation-sensitive C⨍oI, indicated that the otherwise heavily methylated ODC gene(s) were rendered hypomethylated in the myeloma cells resistant to dexamethasone. This hypomethylation within and/or around ODC genes was associated with a 2–4-fold enhancement of accumulation of ODC mRNA.

【 授权许可】

Unknown