Sex-related differences in bladder cancer have implicated the androgen receptor (AR) as a potential therapeutic target but the role of AR in this disease is still unclear. The aim of this study was to characterise AR signalling and determine the functional consequences of AR activation in bladder cancer cell line models.
Western blotting and immunofluorescence were used to assess AR expression and nuclear localisation in three bladder cancer cell lines (UMUC3, T24, TCCSUP) previously reported to be AR-positive [1,2]. Cell proliferation, viability, and clonogenicity were measured using Coulter Counter, Cell Titre-Glow, and Colony-Formation Assays, respectively, to evaluate the effects of AR activation on bladder cancer cell lines.
Low AR protein expression was detected in the UMUC3 cell line by Western blot, but AR was undetectable in the T24 and TCCSUP cell lines. In UMUC3 cells, treatment with the AR agonist 5α-dihydrotestosterone (DHT; 1nM; 48hr) stabilised AR protein expression and induced protein expression of one (SEC14L2) but not another (FKBP5) factor commonly regulated by AR in target tissues. Immunofluorescence showed nuclear localisation of AR in a small sub-population of UMUC3 cells (~12% with 1nM DHT and ~18% with 10nM DHT). AR activation did not affect proliferation, viability, or clonogenic capacity of UMUC3 cells compared to the control.
These findings refute previous reports of AR expression in T24 and TCCSUP bladder cancer cell lines but confirm AR positivity in the UMUC3 line. However, features of canonical AR signalling were only observed in a small sub-population of UMUC3 cells, likely explaining the lack of significant effects of androgen treatment on proliferation, viability, and colony formation. Therefore, to determine the functional role of AR in bladder cancer, alternative models such as patient-derived explants, xenografts, and organoids that retain AR expression are needed.