TY - JOUR
T1 - Rapid inhibition of c-myc gene expression by a glucocorticoid in the avian oviduct
AU - Rories, Charles
AU - Lau, Chu Kwan
AU - Fink, Karen
AU - Spelsberg, Thomas C.
PY - 1989/6
Y1 - 1989/6
N2 - The glucocorticoid dexamethasone (DEX) causes a rapid, reversible reduction in c-myc mRNA level in the oviducts of estrogen-treated, immature chickens. The c-myc mRNA level begins to decrease by 5 min after injection of 0.5 mg DEX, reaches a minimum of 10% of the control value by 30 min, and returns to 30-40% of the control value by 4 h post injection. This rapid effect of DEX on the c-myc mRNA level occurs in both diethylstilbestrol-stimu-lated and diethylstilbestrol-withdrawn oviducts. The effect is dose dependent, with reduction of the c-myc mRNA measured with as little as 10 µg DEX injection (0.03 µg/g BW). The effect of the steroid is gene specific with H2B histone mRNA displaying a significantly reduced response. The effect is also tissue specific with liver displaying an increase of 170% of control values in c-myc mRNA level by 30 min after injection of 0.5 mg DEX. The reduction of avian oviduct c-myc mRNA levels by DEX may play a role in glucocorticoid inhibition of cell proliferation in this tissue. The rapidity of the steroid effects on c-myc expression makes it likely that the steroid-induced reduction of c-myc mRNA levels represents a direct primary action of the steroid-receptor complex on the c-myc gene expression.
AB - The glucocorticoid dexamethasone (DEX) causes a rapid, reversible reduction in c-myc mRNA level in the oviducts of estrogen-treated, immature chickens. The c-myc mRNA level begins to decrease by 5 min after injection of 0.5 mg DEX, reaches a minimum of 10% of the control value by 30 min, and returns to 30-40% of the control value by 4 h post injection. This rapid effect of DEX on the c-myc mRNA level occurs in both diethylstilbestrol-stimu-lated and diethylstilbestrol-withdrawn oviducts. The effect is dose dependent, with reduction of the c-myc mRNA measured with as little as 10 µg DEX injection (0.03 µg/g BW). The effect of the steroid is gene specific with H2B histone mRNA displaying a significantly reduced response. The effect is also tissue specific with liver displaying an increase of 170% of control values in c-myc mRNA level by 30 min after injection of 0.5 mg DEX. The reduction of avian oviduct c-myc mRNA levels by DEX may play a role in glucocorticoid inhibition of cell proliferation in this tissue. The rapidity of the steroid effects on c-myc expression makes it likely that the steroid-induced reduction of c-myc mRNA levels represents a direct primary action of the steroid-receptor complex on the c-myc gene expression.
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U2 - 10.1210/mend-3-6-991
DO - 10.1210/mend-3-6-991
M3 - Article
C2 - 2739662
AN - SCOPUS:0024374952
SN - 0888-8809
VL - 3
SP - 991
EP - 1001
JO - Molecular Endocrinology
JF - Molecular Endocrinology
IS - 6
ER -