Human-Based Exposure Levels of Perfluoroalkyl Acids May Induce Harmful Effects to Health by Disrupting Major Components of Androgen Receptor Signalling In Vitro

Abstract

Perfluoroalkyl acids (PFAAs) are detectable in human blood. PFAA exposure may contribute to androgen receptor (AR)-related health effects such as prostate cancer (PCa). In Norway and Sweden, exposures to PFAAs and PCa are very real concerns. In vitro studies conventionally do not investigate PFAA-induced AR disruption at human blood-based concentrations, thus limiting application to human health. We aim to determine the endocrine disrupting activity of PFAAs based upon human exposure levels, on AR transactivation and translocation. PFAAs (PFOS, PFOA, PFNA, PFDA, PFHxS, and PFUnDA) were tested at concentrations ranging from 1/10 × to 500 × relative to human blood based upon the exposure levels observed in a Scandinavian population. Translocation was measured by high content analysis (HCA) and transactivation was measured by reporter gene assay (RGA). No agonist activity (translocation or transactivation) was detected for any PFAAs. In the presence of testosterone, AR translocation increased following exposure to PFOS 1/10 × and 100 ×, PFOA 1/10 ×, and PFNA 1 × and 500 × (P < 0.05). In the presence of testosterone, PFOS 500 × antagonised AR transactivation, whereas PFDA 500 × increased AR transactivation (P < 0.05). PFAAs may contribute to AR-related adverse health effects such as PCa. PFAAs can disrupt AR signalling via two major components: translocation and transactivation. PFAAs which disrupt one signalling component do not necessarily disrupt both. Therefore, to fully investigate the disruptive effect of human exposure-based contaminants on AR signalling, it is imperative to analyse multiple molecular components as not all compounds induce a disruptive effect at the same level of receptor signalling.