Retinoic acid receptor expression vector inhibits differentiation of F9 embryonal carcinoma cells.
Expression vectors have been constructed for a region of the human retinoic acid receptor-alpha (hRAR-alpha) and transferred into F9 embryonal carcinoma (EC) cells. When the vectors are overexpressed in F9 cells, clones can be selected for resistance to retinoic acid-induced differentiation. This effect is obtained even when the hRAR-alpha region is expressed as a beta-galactosidase fusion protein. Using the beta-galactosidase component of the fusion protein as a marker, overexpression of the fusion protein has been correlated with the retinoic acid-resistance effect. The clones resistant to retinoic acid no longer exhibit the normal retinoic acid induction of endo B cytokeratin, laminin B-1, and tissue plasminogen activator mRNAs observed with normal F9 cells. Retinoic acid induction of type IV alpha-1 collagen and Hox-1.3 RNAs is observed with these clones. When transfected with a thyroid receptor DNA-binding sequence (TRE)/thymidine kinase promoter/luciferase construct, the retinoic acid-resistant clones do not yield the same retinoic acid-induced level of luciferase obtained with F9 cells. It is hypothesized that the RAR vectors are interfering with endogenous RAR(s) in a dominant-negative manner to inhibit retinoic acid-induced differentiation of F9 EC cells.
Espeseth
A S
AS
Department of Microbiology and Immunology, Duke University Medical Center, North Carolina 27710.
Murphy
S P
SP
Linney
E
E
D015152:Blotting, Northern; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics* / Q000502:physiology; D002454:Cell Differentiation; D002460:Cell Line; D003001:Cloning, Molecular; D054278:Embryonal Carcinoma Stem Cells; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D014411:Neoplastic Stem Cells; D010641:Phenotype; D018168:Receptors, Retinoic Acid; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*
D002352:Carrier Proteins; D018168:Receptors, Retinoic Acid; D011993:Recombinant Fusion Proteins; D014212:Tretinoin