Biomarkers Oct4 and Sox-2 May Predict DPSC Viability Following Cryopreservation

Objectives: Many studies have demonstrated clinical applications for the use of dental pulp stem cells (DPSC) for the treatment of various conditions, which have driven medical and scientific interest in the collection, isolation and banking of DPSC tissues for research into these potential therapies. Few studies to date have evaluated the viability of DPSC following long-term cryopreservation. Based upon the paucity of information regarding long-term viability and biological markers for DPSC, the current objectives of this study were to characterize and evaluate the effects of long-term cryopreservation, as well as to identify biomarkers that may be useful for future potential screening and applications.
Methods: Using previously collected DPSC isolates, growth and viability over a period of four years were evaluated and plotted. RNA isolated at each time was retrieved for screening using DPSC biomarkers and RT-PCR.
Results: This analysis revealed an overall decline in viability at each time point that did not appear to be linear. Viability for rapidly dividing DPSC declined less than for DPSC isolates with slower doubling times and growth. In addition, the analysis of specific intracellular biomarkers, including Nestin, NANOG, Sox-2 and Oct4 revealed that Oct4 and Sox-2 may be associated with the observed changes in viability among these DPSC isolates.
Conclusions: Based upon these results, NANOG, Sox-2 and Oct4 expression may bethe most important variable factors and biomarkers associated with both DPSC growth rate and viability during cryopreservation. This information may be useful for future applications and therapies that could screen and sort DPSC using predetermined biomarkers to improve both efficiency and feasibility.