The effect of insulin and insulin-like growth factors on the expression of steroidogenic enzymes in a human ovarian thecal-like tumor cell model.
OBJECTIVE
To determine the effects of insulin and insulin-like growth factors (IGF-I and IGF-II) on steroidogenesis and steroidogenic enzyme expression in a human ovarian thecal-like tumor cell culture model system.


METHODS
Human ovarian thecal-like tumor cells treated with forskolin and insulin IGF-I or IGF-II were evaluated for media accumulation of P and androstenedione (A) as well as 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) and cytochrome P450 17 alpha-hydroxylase (P450c17) enzyme activity. Northern analysis of cytochrome P450 side chain cleavage (P450scc), P450c17, and 3 beta HSD messenger RNA (mRNA) also was performed.


RESULTS
Basal hormone secretion, enzyme activity, and mRNA levels were not affected by treatment with insulin or the IGFs. Forskolin treatment stimulated steroid production, enzyme activity, and mRNA content. Forskolin-stimulated P secretion was augmented 30% by treatment with insulin and IGFs, whereas 3 beta HSD activity was augmented twofold to threefold. Forskolin stimulated A and P450c17 activity were enhanced by treatment with insulin and the IGFs. In forskolin-treated cells. P450c17 and P450scc mRNA levels were not affected by insulin (100 nM) or IGF (10 nM) treatment; however, 3 beta HSD mRNA levels were augmented by treatment with insulin and IGFs.


CONCLUSIONS
We observed that forskolin-stimulated human ovarian thecal-like tumor cell steroidogenesis, P450c17, and 3 beta HSD activity, as well as mRNA content for P450scc, 3 beta HSD, and P450c17. Insulin and the IGFs augmented forskolin-stimulated production of P and the expression of 3 beta HSD, with little effect on A production, P450scc, or P450c17 expression.
McGee
E A
EA
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas 75235-9032, USA.
Sawetawan
C
C
Bird
I
I
Rainey
W E
WE
Carr
B R
BR
D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000735:Androstenedione / Q000378:metabolism; D001483:Base Sequence; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010051:Ovarian Neoplasms / Q000201:enzymology*; D011374:Progesterone / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D013002:Somatomedins / Q000494:pharmacology*; D013255:Steroid 21-Hydroxylase / Q000235:genetics / Q000378:metabolism; D013256:Steroids / Q000096:biosynthesis*; D013799:Theca Cells / Q000201:enzymology*; D014407:Tumor Cells, Cultured
D007328:Insulin; D012333:RNA, Messenger; D013002:Somatomedins; D013256:Steroids; D000735:Androstenedione; D011374:Progesterone; D015096:3-Hydroxysteroid Dehydrogenases; D013255:Steroid 21-Hydroxylase; D002786:Cholesterol Side-Chain Cleavage Enzyme