Product of aromatase activity in intact LNCaP and MCF-7 human cancer cells

• Published in: Journal of steroid biochemistry and molecular biology 1997-04, Vol.61 (3), p.287-292
• Main Authors: Castagnetta, Luigi A.M., Granata, Orazia M., Bellavia, Vincenzo, Amodio, Rosalba, Scaccianoce, Eugenia, Notarbartolo, Monica, Follari, Maria R., Miceli, M.Dora, Carruba, Giuseppe
• Format: Article
• Language: English
• Subjects: Androgens - metabolism; Aromatase - analysis; Biological and medical sciences; Breast Neoplasms - enzymology; Estrogens - metabolism; Female; Gynecology. Andrology. Obstetrics; Humans; Male; Mammary gland diseases; Medical sciences; Prostatic Neoplasms - enzymology; Tumor Cells, Cultured; Tumors
• ISSN: 0960-0760; 1879-1220
• DOI: 10.1016/S0960-0760(97)80025-8

We investigated conversion rates of androgens to estrogens in cultured, hormone-responsive prostate (LNCaP) and breast (MCF-7) human cancer cells. For this purpose, we adopted an intact cell analysis, whereby cells were incubated for different incubation times in the presence of close-to-physiological (1 nM) or supraphysiological (1 μM) concentrations of labelled androgen precursors, i.e. testosterone (T) and androstenedione (Δ 4Ad). The aromatase activity, as measured by estrogen formation, was detected in LNCaP cells (0.5 pmol/ml), even though to a significantly lower extent than in MCF-7 cells (5.4 pmol/ml), using 1 μM T after 72 h incubation. Surprisingly, LNCaP cells displayed a much higher aromatase activity when T was used as a substrate with respect to Δ 4Ad. In either cell line, T transformation to Δ 4Ad was relatively low, attaining only 2.8% in LNCaP and 7.5% MCF-7 cells. However, T was mostly converted to conjugates (over 95%), glucuronides and some sulphates, in LNCaP cells, whereas it was only partly converted to sulphates (