A novel GC-MS methodology to evaluate aromatase activity in human placental microsomes: a comparative study with the standard radiometric assay.

A novel GC-MS methodology to evaluate aromatase activity in human placental microsomes: a comparative study with the standard radiometric assay. Anal Bioanal Chem. 2019 Aug 22;: Authors: Augusto TV, Cunha SC, Amaral C, Fernandes JO, da Silva ET, Roleira FFM, Teixeira N, Correia-da-Silva G Abstract Estrogens are key factors in the development of the estrogen receptor-positive (ER+) breast cancer. Estrogens, estrone (E1), and estradiol (E2) production is achieved by aromatase, a cytochrome P450 enzyme that has androgens, androstenedione (AD), and testosterone (T) as substrates. Nowadays, third-generation aromatase inhibitors (AIs) are considered the gold-standard treatment for ER+ breast cancer in postmenopausal women as well as in premenopausal women with ovary ablation. Aromatase activity assessment still relies on radiometric assays that are expensive, hazardous, and non-environmentally friendly. Thus, in order to overcome these disadvantages, a new methodology was developed to evaluate aromatase activity, based on dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC-MS). The enzymatic reaction was carried out in human placental microsomes, using AD as substrate, and the anti-aromatase activity was measured by determining the conversion percentage of AD into E1 (ratio E1/AD) using isotopic analogues as internal standards. The method showed good linearity (r2 = 0.9908 for AD and 0....
Source: Analytical and Bioanalytical Chemistry - Category: Chemistry Authors: Tags: Anal Bioanal Chem Source Type: research