"Background: Hypospadias is a common congenital abnormality with varying severity. There may be lack of local tissue during hypospadias surgery. Oral mucosa (OM) is widely used for urethroplasties and repair after failed hypospadias in adults. Little is known about the applicability of OM in prepubertal boys because of eventual hormonal effect of puberty on OM. We investigated the androgen receptor (AR) localization and testosterone sensitivity in OM.
Materials & Methods: Small waste OM fragments of adult patients undergoing urethral surgery were collected under local biobank protocol. AR staining was performed on tissue sections and tissue was used for isolation of oral keratinocytes. Cells were serum starved, exposed to testosterone for different time points followed by immunostaining for AR.
Results: OM of patients with normal testosterone levels showed nuclear AR localization in the basal layer, and cytoplasmic AR localization in the apical layer, whereas OM of an adult hypospadias patient showed low cytoplasmic AR expression. The basal layer was Ki-67 positive, associated with cell proliferation. Oral keratinocytes of adult hypospadias patient exposed to testosterone showed switch from cytoplasmic to nuclear localized AR after 60 minutes, indicating that testosterone signaling was activated.
Conclusions: Oral keratinocytes are sensitive to testosterone. These findings suggest that OM is responsive to testosterone. Therefore an autograft transplant of OM in prepubertal boys might be suitable and able to keep up with the testosterone induced penile growth. In addition, this is an indication that OM cells can be used in tissue engineering for urethral reconstruction in pediatric patients."