AIMThe aim of this study was to confirm the multilineage differentiation ability of dental pulp stem cells (DPSCs) from green fluorescent protein (GFP) transgenic mice. The expression of GFP in DPSCs was also observed during differentiation.

METHODOLOGYDPSCs were harvested from the dental pulp tissue of transgenic nude mice, and then transferred to osteogenic, adipogenic, and chondrogenic media. The morphological characterization of induced cells was observed by microscopy and histological staining. The expression of marker genes was measured by RT-PCR.

RESULTSThe endogenous GFP and multilineage potential of transgenic DPSCs had no influence on each other. Moreover, the results of fluorescence microscopic imaging suggest that there was no significant decline of GFP expression during DPSCs differentiation.

CONCLUSIONAs the population of GFP labeled DPSCs can be easily identified, this will be a promising method for tracking DPSCs in vivo.

Adipocytes ; cytology ; Adipogenesis ; physiology ; Animals ; Anthraquinones ; Azo Compounds ; Cell Culture Techniques ; Cell Differentiation ; physiology ; Cell Lineage ; physiology ; Chondrocytes ; cytology ; Chondrogenesis ; physiology ; Coloring Agents ; Culture Media ; Dental Pulp ; cytology ; Genetic Markers ; genetics ; Green Fluorescent Proteins ; analysis ; genetics ; Mice ; Mice, Nude ; Mice, Transgenic ; Microscopy, Fluorescence ; Osteoblasts ; cytology ; Osteogenesis ; physiology ; RNA ; analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Stem Cells ; cytology ; physiology ; Tissue Culture Techniques ; Tolonium Chloride

AIMTo investigate the effect of DAPT (gamma-secretase inhibitor) on the growth of human tongue carcinoma cells and to determine the molecular mechanism to enable the potential application of DAPT to the treatment of tongue carcinoma.

METHODOLOGYHuman tongue carcinoma Tca8113 cells were cultured with DAPT. Cell growth was determined using Indigotic Reduction method. The cell cycle and apoptosis were analyzed by flow cytometry. Real-time PCR and Immuno-Fluorescence (IF) were employed to determine the intracellular expression levels.

RESULTSDAPT inhibited the growth of human tongue carcinoma Tca8113 cells by inducing G0-G1 cell cycle arrest and apoptosis. The mRNA levels of Hairy/Enhancer of Split-1 (Hes-1), a target of Notch activation, were reduced by DAPT in a dose-dependent manner. Coincident with this observation, DAPT induced a dose-dependent promotion of constitutive Caspase-3 in Tca8113 cells.

CONCLUSIONDAPT may have a therapeutic value for human tongue carcinoma. Moreover, the effects of DAPT in tumor inhibition may arise partly via the modulation of Notch-1 and Caspase-3.

Amyloid Precursor Protein Secretases ; antagonists & inhibitors ; Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Basic Helix-Loop-Helix Transcription Factors ; drug effects ; Carcinoma ; pathology ; Caspase 3 ; drug effects ; Cell Line, Tumor ; Cell Membrane ; drug effects ; Cell Nucleus ; drug effects ; Cyclin D1 ; drug effects ; Dipeptides ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; G1 Phase ; drug effects ; Homeodomain Proteins ; drug effects ; Humans ; Receptor, Notch1 ; drug effects ; Repressor Proteins ; drug effects ; Resting Phase, Cell Cycle ; drug effects ; Tongue Neoplasms ; pathology ; Transcription Factor HES-1