chapter  7
8 Pages

Adrenocortical Toxicology In Vitro: Assessment of Steroidogenic Enzyme Expression and Steroid Production in H295R Cells

ByThomas Sanderson

The H295 and H295R human adrenocortical carcinoma (a subpopulation of H295 that forms adherent monolayers in culture) cell lines have been characterized in detail and shown to be useful tools for the study of adrenocortical function and steroidogenesis. The H295R cell line is preferably used as its adherent properties make it easier to culture and more suitable for experimental manipulation. The H295 and H295R cell lines express all the key enzymes necessary for steroidogenesis (Gazdar et al., 1990; Rainey et al., 1993; Rainey et al., 1994; Sanderson et al., 2000; Staels et al., 1993). These include CYP11A (cholesterol side-chain cleavge), CYP11B1, CYP11B2 (aldosterone synthetase), CYP17 (17-hydroxylase and 17,20-lyase), CYP19 (aromatase), CYP21, type 2 3-HSD (hydroxysteroid dehydrogenase), and types 1 and 4 17-HSD. The cells have the physiological characteristics of zonally undifferentiated human fetal adrenal cells (Gazdar et al., 1990; Staels et al., 1993), with the ability to produce the steroid hormones of each of the three phenotypically distinct zones found in the adult adrenal cortex (Neville and O’Hare, 1985). These are the zona granulosa that produces the mineralocorticoid aldosterone, the zona fasciculata that produces the glucocorticoid cortisol, and the zona reticularis that produces the weak androgens

Figure 1 Enzyme expression and steroid production in the zona glomerulosa, zona fasciculata, and zona reticularis of the adrenal cortex.