Methyleseleninic acid downregulates aromatase

Cytochrome P 450 aromatase (CYP19) is the key enzyme required for oestrogen biosynthesis and is responsible for converting androgens to oestrogens. Oestrogen is known to play a critical role in breast cancer development and progression, making aromatase an important target for breast cancer prevention and therapy.

Although aromatase inhibitors have been used as first line of therapy for oestrogen receptor-positive breast cancer in post menopausal women, their use has been limited by toxicities and high costs. Gao et al. show that methylseleninic acid (MSA), can effectively suppress aromatase activation by dexamethasone and forskolin. MSA suppression of aromatase activation is not mediated through direct inhibition of aromatase enzymatic activity but is attributable to a marked downregulation of promoters PI.4- and PII-specific aromatase mRNA expression and thereby reduction of aromatase protein. Considering the low-cost and low-toxicity nature of MSA, their findings provide a strong rationale for development of MSA as a breast cancer chemo-preventive agent for obese postmenopausal women. Gao et al. (2012) Journal of Endocrinology 212 199-205.

Read full article at DOI: 10.1530/JOE-11-0363.