Comparative assessment of cultures from oral and urethral stem cells for urethral regeneration

Urethral reconstruction has received much attention in recent years, due to pathologies such as recurrence of urethral strictures after treatments. Various surgical techniques have been developed to obtain the best risk-benefit ratio, such as autologous grafts taken from the oral cavity. Tissue engineering and stem cells, growing tissue from a small biopsies, can further improve surgery, reducing invasiveness and morbidity. To determine whether urethra or other epithelia can be equally useful for urethra engineering, a comparison of clonogenic ability, proliferative potential and stem cell markers should be obtained. In this study, 19 biopsies from urethra, and 21 from oral mucosa were obtained from patients, during reconstructive surgery. Urethral and oral tissues were removed from the same donor, to develop primary cultures and cell characterization. The long term regenerative properties of both tissues was investigated in vitro by life span, clonal analysis and markers of different clonal types. Results revealed the same high proliferative potential for urethra and oral mucosa cultures, but maintenance of specific markers. Karyotype and growth factor dependence confirmed the normal phenotype of cultured cells. Clonal analysis of the proliferative compartment highlighted a very different proportion of stem and transient amplifying cells, characterised by dissimilar cell size profile and marker expression. In conclusion, both tissues can be cultured and preserve their stem cells in vitro. Few differences appeared in oral mucosa vs urethra, suggesting that they can be equally useful for tissue engineering of the urethral tract.