ABSTRACT
Based on the high self-renewal ability and osteoblastic differentiation capacity, dental pulp stem cells (DPSCs) are suggested to be promising cell source for osteogenesis. Therefore, illustrating the mechanism of osteoblastic differentiation of DPSCs is required. This current study aims to illustrate the role and mechanism of Sp1 in regulating osteoblastic differentiation of DPSCs. In this study, we downregulated Sp1 in DPSCs and evaluated the osteoblastic differentiation by measuring Runx2 and OCN expression with Western blot analysis and by Alizarin red staining. Furthermore, we investigated the mechanism of Sp1 regulating noggin with Firefly luciferase reporter gene assay and ChIP assay, and correspondingly evaluated the function of noggin in Sp1-regulated osteoblastic differentiation of DPSCs. We found that knockdown of Sp1 inhibits the expression of ALP, Runx2, COL1A1 and OCN, and decreases ALP staining, Alizarin red staining. Sp1 binds to noggin promoter and inhibits noggin expression, thus correspondingly regulates DPSCs osteoblastic differentiation. In conclusion, our study revealed that Sp1 regulates DPSCs osteoblastic differentiation through noggin and that Sp1/noggin can provide new perspective for enhancing DPSCs osteogenesis.
Subject(s)
Carrier Proteins/genetics , Cell Differentiation , Dental Pulp/cytology , Osteoblasts/cytology , Osteoblasts/metabolism , Sp1 Transcription Factor/genetics , Carrier Proteins/metabolism , Cell Differentiation/genetics , Down-Regulation/genetics , Gene Knockdown Techniques , Humans , Promoter Regions, Genetic/genetics , Sp1 Transcription Factor/metabolism , Stem Cells/cytology , Stem Cells/metabolism , Transcription, Genetic , Up-Regulation/geneticsABSTRACT
BACKGROUND: Oral squamous cell carcinoma (OSCC) is a frequently diagnosed life-threatening oral cancer worldwide and has become one of the leading causes of cancer-related mortality. However, the pathogenesis of this disease is very limited. OBJECTIVE: In this study, we aimed to investigate the functional relationship between OSCC and a potential tumor related gene ubiquitin-specific proteases 39 (USP39). METHODS: The lentivirus-based RNA interference was utilized to knock down USP39 expression in human OSCC CAL27 cells. The effect of USP39 on cell proliferation was detected by MTT and colony formation assays. RESULTS: The results uncovered that the proliferation rate was significantly decreased in specific USP39-targeting lentivirus infected cells compared to control lentivirus infected cells. The colony formation capacity was also attenuated in CAL27 cells after USP39 knockdown. Moreover, knockdown of USP39 arrested CAL27 cells in S and G1/M phases of the cell cycle. Furthermore, USP39 silencing induced apoptosis of CAL27 cells via activations of Caspase 3 and PARP. CONCLUSIONS: In conclusion, the inhibition of USP39 in CAL27 cells suppressed cell growth probably via induction cell cycle arrest and apoptosis. USP39 might act as an oncogenic factor in OSCC and could be a potential molecular target for OSCC gene therapy.
Subject(s)
Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , Mouth Neoplasms/genetics , Mouth Neoplasms/pathology , RNA Interference , Ubiquitin-Specific Proteases/genetics , Apoptosis , Cell Cycle/genetics , Cell Line, Tumor , Cell Proliferation , Gene Knockdown Techniques , Gene Silencing , Genetic Vectors/genetics , Humans , Lentivirus/genetics , RNA, Small Interfering/geneticsABSTRACT
BACKGROUND: The Nemo-like kinase (NLK) is a serine/threonine-protein kinase that involved in a number of signaling pathways regulating cell fate. Variation of NLK has been shown to be associated with the risk of cancer. However, the function of NLK in oral adenosquamous carcinoma cells line CAL-27 is unknown. METHODS: In this study, we evaluated the function of NLK in CAL-27 cells by using lentivirus-mediated RNA silence. The targeted gene expression, cell proliferation and cell cycle are investigated by RT-PCR, western-blot, MTT method, colony forming assay and flow cytometry analysis respectively. RESULTS: After NLK silencing, the number of colonies was significantly reduced (54 ± 5 colonies/well compared with 262 ± 18 colonies/well in non-infected or 226 ± 4 colonies/well in negative control group (sequence not related to NLK sequence with mismatched bases). Using crystal violet staining, we also found that the cell number per colony was dramatically reduced. The RNA silencing of NLK blocks the G0/G1 phase to S phase progression during the cell cycle. CONCLUSIONS: These results suggest that NLK silencing by lentivirus-mediated RNA interference would be a potential therapeutic method to control oral squamous carcinoma growth.
