Activity and expression of progesterone metabolizing 5α-reductase, 20α-hydroxysteroid oxidoreductase and 3α(β)-hydroxysteroid oxidoreductases in tumorigenic (MCF-7, MDA-MB-231, T-47D) and nontumorigenic (MCF-10A) human breast cancer cells

Table 2 5α-Reductase, 20α-HSO and 3α-HSO activities in microsomes/cytosol of breast cell lines.

Cells	5αR	20α-HSO (reductive)	3α-HSO (reductive)	5αR/20α-HSO	5αR/3α-HSO
MCF-7	228.6 (86.5)	17.9 (6.8)	17.9 (6.8)	12.77	12.77
MDA231	186.2 (75.3)	49.8 (20.1)	11.3 (4.6)	3.74	16.48
T-47D	82.1 (74.5)	21.8 (19.8)	6.3 (5.7)	3.77	13.03
MCF-10A	78.3 (7.6)	845.1 (81.4)	114.2 (11.0)	0.93	0.69

The 10,000 × g supernatant of cell homogenates was incubated with NADH, NADPH and [³H]progesterone, and enzyme activities were determined by quantifying metabolites formed as a result of specific enzyme actions (See Methods for details). Values (mean from two experiments) are given as pg/hour/mg protein; the values in brackets show the percent of total enzyme activities for a particular cell type.

ISSN: 1471-2407