Estrogen synthesis in human colon cancer epithelial cells.
Article Details
- CitationCopy to clipboard
Fiorelli G, Picariello L, Martineti V, Tonelli F, Brandi ML
Estrogen synthesis in human colon cancer epithelial cells.
J Steroid Biochem Mol Biol. 1999 Dec 31;71(5-6):223-30.
- PubMed ID
- 10704911 [ View in PubMed]
- Abstract
Epidemiological and experimental data suggest an involvement of estrogen in the development and progression of colorectal cancer. In order to determine whether local synthesis of estrogen occurred in human colonic cancer cells, two colorectal cancer cell lines, HCT8 and HCT116, were evaluated for gene expression and enzyme activity of cytochrome P450 aromatase. In addition, the effect on aromatase expression of charcoal-stripped fetal calf serum, of quercetin and genistein and of tamoxifen and raloxifene was investigated in both cell lines. RT-PCR analysis revealed that colorectal adenocarcinoma cell lines contain aromatase as a major component. The conversion of [(3)H]-androstenedione to estrone and labeled water was dose-dependently inhibited by 4-hydroxyandrostenedione and obeyed Michaelis-Menten kinetic with apparent Km values of approximately 20 nM and V(max) values of approx. 200 and 500 fmol/mg protein/h for HCT8 and HCT116 cells, respectively. After 24 h incubation, genistein (1 microM) significantly increased aromatase activity in HCT8 cells, with no effect on HCT116 cells. In accord with previous observation in reproductive tissues, quercetin (1 microM) significantly inhibited the enzyme activity in both cell lines. Also tamoxifen (100 nM) acted as inhibitor, while raloxifene (10 nM) decreased the enzyme activity only in HCT116 cells. The aromatase gene expression modulation by these effective agents was consistent with their effects on enzyme activity. These findings demonstrate for the first time that colorectal adenocarcinoma cell lines express aromatase. Interestingly, the enzyme activity was inhibited by quercetin, one major dietary flavonoid, by tamoxifen, a hormonal therapeutic agent for breast cancer, and by raloxifene, used in the prevention of postmenopausal osteoporosis.
DrugBank Data that Cites this Article
- Drug Enzymes
Drug Enzyme Kind Organism Pharmacological Action Actions Raloxifene Cytochrome P450 19A1 Protein Humans UnknownInhibitorDetails Tamoxifen Cytochrome P450 19A1 Protein Humans UnknownInhibitorDetails - Pharmaco-transcriptomics
Drug Drug Groups Gene Gene ID Change Interaction Chromosome Quercetin Experimental Investigational CYP19A1 1588 downregulated Quercetin results in decreased expression of CYP19A1 mRNA 15q21.2 Raloxifene Approved Investigational CYP19A1 1588 downregulated Raloxifene Hydrochloride results in decreased expression of CYP19A1 mRNA 15q21.2 Tamoxifen Approved CYP19A1 1588 downregulated Tamoxifen results in decreased expression of CYP19A1 mRNA 15q21.2