MP19-15 COMPARATIVE ASSESSMENT OF ORAL AND URETHRAL MUCOSA CELL CULTURES AND IN VITRO ANALYSIS OF THEIR REGENERATIVE AND PROLIFERATIVE PROPERTIES FOR TISSUE ENGINEERING URETHRAL RECONSTRUCTION

Abstract

INTRODUCTION AND OBJECTIVES: The success of tissue engineering for urethral reconstruction depends on the quality of the cultures used to prepare the grafts. We investigated the quality and the safety of cultured oral and urethra mucosa cells by comparing them, in order to determine the long-term in vitro regenerative properties, the capability to maintain their differentiation program, the heterogeneity of proliferative cell pool and the differentiation potential clonogenicity. METHODS: Urethral and oral specimens were obtained in accordance with the tenets of the Declaration of Helsinki from 18 patients who underwent urethroplasty with oral mucosal graft. The primary objectives of the analysis were to determine the cell yield and migratory capacity of oral and urethral mucosa cells, to compare the protein expression, to report the clonogenicity and the long-term proliferative potential. Furthermore we characterised stem cells of urethral and oral epithelia by holoclones analysis. Finally we investigated the safety of in vitro models regard cell growth. RESULTS: A statistically significant higher cell yield was obtained from oral mucosa than from urethra (t-test p1⁄40,02419), but no significant differences in the number of epithelial clones. Proximity of replicative senescence boosts cell cycle (faster woundhealing capacity) in oral mucosal more than in urethra. Keratinocytes from urethral and oral mucosa underwent a mean of 79.3 and 84 cell divisions, respectively, before senescence. A similar number of holoclones, meroclones and paraclones were found in oral mucosal and urethral proliferative compartments. It is shown that a single cultured stem cell maintains 100% clonogenicity, can be identified by selected markers and can provide differentiation. Analysis of protein expression suggests maintenance of a sitespecific differentiation programme, even under culture conditions. No tumorigenicity or other abnormal cell growth developed in cultured tissues. CONCLUSIONS: The comparison of all parameters highlighted a wide similarity of the oral and urethral mucosal cells, with better wound healing via oral epithelium. The oral mucosa cells seem to have a faster wound-healing capacity and a longer replicative survival. This data might have a clinical impact regard the current longer life expectancy of our patients.