Abstract 3374: Characterizing a new population of adult mouse submandibular gland stem cells

Abstract

Abstract Xerostomia or dry mouth is a hyposalivation condition that leads to difficulty in speaking, eating, mucosal pain, and enhanced risk of dental and mandibular infection. It can be due to damage of salivary gland nervous system, medications, systematic diseases such as diabetes and Sjogen's syndrome, and radiotherapy (RT) for head and neck cancer. Current available treatments are ineffective due to limited residual glandular function. Stem cell transplantation therapy may be a very promising future direction in treating this severe condition. Using fluorescence-activated cell sorting (FACS) method, we have successfully identified a new population of stem cells from adult mouse submandibular gland. Among all the populations of cells evaluated, the c-Kit+/Sca1+/CD24+/lin− cells generated the highest number of salispheres when cultured in vitro, at least 4 folds more than c-Kit+ or Sca1+ only cells. The c-Kit+/Sca1+/CD24+/lin− cells also expressed significantly higher level of embryonic salivary stem cell marker keratin 5 (CK5) and the basolateral secretory duct maker keratin 14 (CK14), when compared to the CD24+/lin− epithelial cell population. MTT assay showed salispheres derived from c-Kit+/Sca1+/CD24+/lin− population exhibited 10 folds higher enzyme activity than control populations. These spheres continued to express stem cell markers c-Kit and Sca1 after Day 21 and proliferate (Ki67 staining) actively after 14 days in vitro. In addition, these salispheres differentiated into functional acinar cells, indicated by a-amylase staining. More importantly, the dissociated 1st generation of salispheres was capable of generating 2nd salispheres in vitro, indicating the self-renewal property of the these cells. In conclusion, we have identified a subpopulation of adult salivary gland cells that exhibit stem cell properties. Future work will focus on (1) gene expression studies to further elucidate the molecular characteristics of these cells and (2) confirming their renewal capacity in vivo via transplantation studies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3374. doi:1538-7445.AM2012-3374