TY - JOUR
T1 - Structure-based discovery of the endocrine disrupting effects of hydraulic fracturing chemicals as novel androgen receptor antagonists
AU - Tachachartvanich, Phum
AU - Azhagiya Singam, Ettayapuram Ramaprasad
AU - Durkin, Kathleen A.
AU - Smith, Martyn T.
AU - La Merrill, Michele A.
PY - 2020/10
Y1 - 2020/10
N2 - Hydraulic fracturing (HF) technology is increasingly utilized for oil and gas extraction operations. The widespread use of HF has led to concerns of negative impacts on both the environment and human health. Indeed, the potential endocrine disrupting impacts of HF chemicals is one such knowledge gap. Herein, we used structure-based molecular docking to assess the binding affinities of 60 HF chemicals to the human androgen receptor (AR). Five HF chemicals had relatively high predicted AR binding affinity, suggesting the potential for endocrine disruption. We next assessed androgenic and antiandrogenic activities of these chemicals in vitro. Of the five candidate AR ligands, only Genapol®X–100 significantly modified AR transactivation. To better understand the structural effect of Genapol®X–100 on the potency of AR inhibition, we compared the antiandrogenic activity of Genapol®X–100 with that of its structurally similar chemical, Genapol®X–080. Interestingly, both Genapol®X–100 and Genapol®X–080 elicited an antagonistic effect at AR with 20% relative inhibitory concentrations of 0.43 and 0.89 μM, respectively. Furthermore, we investigated the mechanism of AR inhibition of these two chemicals in vitro, and found that both Genapol®X–100 and Genapol®X–080 inhibited AR through a noncompetitive mechanism. The effect of these two chemicals on the expression of AR responsive genes, e.g. PSA, KLK2, and AR, was also investigated. Genapol®X–100 and Genapol®X–080 altered the expression of these genes. Our findings heighten awareness of endocrine disruption by HF chemicals and provide evidence that noncompetitive antiandrogenic Genapol®X–100 could cause adverse endocrine health effects.
AB - Hydraulic fracturing (HF) technology is increasingly utilized for oil and gas extraction operations. The widespread use of HF has led to concerns of negative impacts on both the environment and human health. Indeed, the potential endocrine disrupting impacts of HF chemicals is one such knowledge gap. Herein, we used structure-based molecular docking to assess the binding affinities of 60 HF chemicals to the human androgen receptor (AR). Five HF chemicals had relatively high predicted AR binding affinity, suggesting the potential for endocrine disruption. We next assessed androgenic and antiandrogenic activities of these chemicals in vitro. Of the five candidate AR ligands, only Genapol®X–100 significantly modified AR transactivation. To better understand the structural effect of Genapol®X–100 on the potency of AR inhibition, we compared the antiandrogenic activity of Genapol®X–100 with that of its structurally similar chemical, Genapol®X–080. Interestingly, both Genapol®X–100 and Genapol®X–080 elicited an antagonistic effect at AR with 20% relative inhibitory concentrations of 0.43 and 0.89 μM, respectively. Furthermore, we investigated the mechanism of AR inhibition of these two chemicals in vitro, and found that both Genapol®X–100 and Genapol®X–080 inhibited AR through a noncompetitive mechanism. The effect of these two chemicals on the expression of AR responsive genes, e.g. PSA, KLK2, and AR, was also investigated. Genapol®X–100 and Genapol®X–080 altered the expression of these genes. Our findings heighten awareness of endocrine disruption by HF chemicals and provide evidence that noncompetitive antiandrogenic Genapol®X–100 could cause adverse endocrine health effects.
KW - Androgen receptor
KW - Antiandrogens
KW - Endocrine disruptors
KW - Fracking
KW - Molecular docking
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U2 - 10.1016/j.chemosphere.2020.127178
DO - 10.1016/j.chemosphere.2020.127178
M3 - Article
C2 - 32505947
AN - SCOPUS:85085754723
VL - 257
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
M1 - 127178
ER -