[Role of specificity protein 1 in transcription regulation of microRNA-92b in head and neck squamous cell carcinoma]

Objective: To investigate the role of transcription factor specificity protein 1 (SP1) in proliferation, migration and invasion in head and neck squamous cell carcinoma (HNSCC), and the role of SP1 in transcription regulation of microRNA (miRNA)-92b. Methods: Predicted the possible target miRNA of transcription factor SP1 by bioinformatic analysis. Furthermore, confirmed the binding sites of transcription factor SP1 and miRNA-92b promoter regions by chromatin immunoprecipitation. After transfecting SP1 siRNA and negative control siRNA, also performed quantitative real-time PCR (qPCR), cell proliferation assay and Transwell assay. Results: The bioinformatic analysis shows SP1 is a possible transcription factor of miRNA-92b. Chromatin immunoprecipitation suggests there are three binding sites in miRNA-92b promoter regions that can be combined with SP1. qPCR suggests in PCI-4A and PCI-37A cells the expression of SP1 in experimental group (respectively was 0.064±0.020 and 0.639±0.008) were significantly lower than negative control group (both were 1)(P<0.05). In PCI-4A and PCI-37A cells the expression of miRNA-92b in experimental group (respectively was 0.215±0.033 and 0.497±0.104) were significantly lower than negative control group (both were 1)(P<0.05). In experimental group proliferation of SP1 in PCI-4A and PCI-37A cells value A were significantly lower than negative control group (P<0.05). In experimental group migration of SP1 in PCI-4A and PCI-37A cells (respectively was 37.0±4.6 and 40.7±2.1) were significantly lower than negative control group (101.0±5.3 and 82.7±5.7) (P<0.05). In experimental group invasion of SP1 in PCI-4A and PCI-37A cells (respectively was 31.3±10.8 and 37.0±4.6) were significantly lower than negative control group (92.3±3.1 and 70.3±3.1)(P<0.05). Conclusions: SP1 promotes proliferation, migration and invasion abilities of HNSCC cells. SP1 is a transcription factor of miRNA-92b and can directly be involved in transcription regulation of miRNA-92b.