Apolipoprotein C-II mRNA levels in primate liver. Induction by estrogen in the human hepatocarcinoma cell line, HepG2.
We have demonstrated that physiological concentrations of 17 beta-estradiol increase nuclear estrogen-specific binding sites in the human hepatoma cell line HepG2 7- to 10-fold and the rate of accumulation of secreted apolipoprotein C-II (apo-C-II), 2.5-fold (Tam, S-P., Archer, T. K., and Deeley, R. G. (1985) J. Biol. Chem. 260, 1670-1675). Apo-C-II is the major activator of lipoprotein lipase, an enzyme which plays a key role in lipoprotein catabolism. In order to define more precisely the mechanism by which estrogen influences apo-C-II production, we have synthesized a triacontanucleotide DNA probe that is complementary to apo-C-II mRNA. We have used the probe both in Northern hybridization experiments and in DNA excess titrations to quantify apo-C-II mRNA in hormonally treated HepG2 cells and various primate tissues. These studies revealed that: 1) the concentration of apo-C-II mRNA in HepG2 cells is comparable with that present in human liver; 2) treatment of the cells with low levels of estrogen results in a doubling of the apo-C-II mRNA concentration; 3) the apo-C-II mRNA concentration in monkey liver is 60- to 70-fold greater than in the intestine and 2.5-fold higher than in human liver.
Archer
T K
TK
Tam
S P
SP
Deugau
K V
KV
Deeley
R G
RG
D000818:Animals; D053304:Apolipoprotein C-II; D001056:Apolipoproteins C / Q000235:genetics*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism*; D002460:Cell Line; D004247:DNA; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008099:Liver / Q000196:embryology / Q000378:metabolism*; D008113:Liver Neoplasms / Q000378:metabolism*; D008252:Macaca fascicularis; D008297:Male; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000378:metabolism*
D053304:Apolipoprotein C-II; D001056:Apolipoproteins C; D012333:RNA, Messenger; D004958:Estradiol; D004247:DNA