BACKGROUND: Hypospadias frequently necessitates surgical urethral reconstruction, sometimes involving oral mucosa (OM) grafts in severe cases. However, the androgen-induced pubertal growth of this graft in the penis depends on the expression of androgen receptors (AR) within the OM and its response to testosterone. This study explores the expression and localization of the androgen receptor (AR) in the human oral mucosa (OM) and assesses its sensitivity to androgens. METHODS: Human OM samples were obtained through a local biobank protocol, and OM cells (OMCs) were isolated. Localization of the AR on the OM was investigated using immunostaining and RT-qPCR was used to investigate AR expression after androgen stimulation. RESULTS: Immunostaining of the OM samples (n=15) unveiled three distinct AR localization patterns: cytoplasmic (n=8), nuclear (n=3), and mixed cytoplasmic-nuclear (n=4). Upon androgen stimulation, the OMCs did not exhibit additional nuclear AR localization with low AR expression according to the RT-qPCR, implying limited androgen responsiveness. CONCLUSIONS: Our study challenges conventional knowledge by revealing limited AR expression on androgen stimulation in human OM. This finding may bear implications for the use of OM in reconstructive surgery for prepubertal boys with hypospadias, as growth limitation might result in functional voiding problems. A comprehensive understanding of AR expression in OM is vital for improving surgical outcomes in such cases.
