Impairment of mesenchymal stem cells derived from oral leukoplakia.

Oral leukoplakia is one of the common precancerous lesions in oral mucosa. To compare the biological characteristics and regenerative capacities of mesenchymal stem cells (MSCs) from oral leukoplakia (epithelial hyperplasia and dysplasia) and normal oral mucosa, MSCs were isolated by enzyme digestion. Then these cells were identified by the expression of MSC related markers, STRO-1, CD105 and CD90, with the absent for the hematopoietic stem cell marker CD34 by flow cytometric detection. The self-renewal ability of MSCs from oral leukoplakia was enhanced, while the multipotent differentiation was descended, compared with MSCs from normal oral mucosa. Fibrin gel was used as a carrier for MSCs transplanted into immunocompromised mice to detect their regenerative capacity. The regenerative capacities of MSCs from oral leukoplakia became impaired partly. Collagen IV (Col IV) and matrix metalloproteinases-9 (MMP-9) were selected to analyze the potential mechanism for the functional changes of MSCs from oral leukoplakia by immunochemical and western blot analysis. The expression of Col IV was decreased and that of MMP-9 was increased by MSCs with the progression of oral leukoplakia, especially in MSCs from epithelial dysplasia. The imbalance between regenerative and metabolic self-regulatory functions of MSCs from oral leukoplakia may be related to the progression of this premalignant disorder.