It is concluded that sulfatase activity is almost twice as potent in cancerous breast tissues than in normal tissues. The sulfatase inhibition at low concentration (5x10(-7) M) was 32.5% and 22.8%, respectively. NOMAC, at the concentration of 5x10(-5) M, inhibited this conversion by 49.2% and 40.8% in cancerous and normal breast tissues, respectively. The sulfatase activity was more intense with breast cancer tissue than normal tissue, since the concentrations of E1 were 42.5 +/- 3.4 and 27.2 +/- 2.5 pg/mg tissue, respectively. It was observed that - E1S was only converted to - E1 and not to - E2, in normal or cancerous breast tissues, which suggests a low or no 17beta-HSD activity under these experimental conditions. Estrone sulfate (E1S), estrone (E1) and E2 were characterized by thin layer chromatography and quantified using the corresponding standard.

Slices of tumoral or normal breast tissues (45-65 mg) were incubated in buffer (20 mM Tris-HCl, pH 7.2) with physiological concentrations of -estrone sulfate (5x10(-9) M), alone or in the presence of nomegestrol acetate (5x10(-5) - 5x10(-7) - 5x10(-9) M), for 4 h at 37 degrees C. In the present study, the effect of NOMAC on sulfatase activity using total breast cancer tissue, compared to the effect in normal breast tissue, was explored.

Previous studies in this laboratory demonstrated that NOMAC can block sulfatase and 17beta-hydroxysteroid dehydrogenase, the enzymes involved in the biosynthesis and transformation of estradiol (E2) in hormone-dependent MCF-7 and T-47D breast cancer cells. Nomegestrol acetate (NOMAC), a 17alpha-hydroxy-nor-progesterone derivative (17alpha-acetoxy-6-methyl-19-nor-4,6-pregnadiene-3,20-dione, the active substance in Lutenyl), is a potent and useful clinical synthetic progestin for the treatment of menopausal complaints and is under current development for oral contraception.

Nomacs 3.4