ProBDNF promotes migration and invasion of SCC-4 cells in oral squamous cell carcinoma by up-regulating p75NTR expression

Abstract:

Objective：To investigate the effect of precursor brain-derived neurotrophic factor（proBDNF） on the migration and invasion of SCC-4 cells in oral squamous cell carcinoma（OSCC），and to explore its underlying mechanism. Methods：After stimulation of SCC-4 cells with 20 ng/mL proBNDF，the cell migration was evaluated by Transwell migration assay and wound healing assay，the cell invasion was evaluated by Transwell invasion assay，and the mRNA and protein expression of p75 neurotrophin receptor （p75NTR） in SCC-4 cells was determined by qRT-PCR and Western blot，respectively. Furthermore，immunofluorescence assay was used to observe the subcellular localization of proBNDF and p75NTR in SCC-4 cells. After knockout of p75NTR，the effects of proB－NDF on cell migration，cell invasion，and expression of genes promoting cell migration and invasion were evaluated by Transwell mi－gration assay and wound healing assay，Transwell invasion assay，and qRT-PCR，respectively. Results：Twenty ng/mL proBDNF signif－icantly promoted the migration and invasion of SCC-4 cells（both P=0.000）. Moreover，pro-BDNF and p75NTR were colo－cated in SCC-4 cells. ProBDNF promoted the mRNA and protein expression of p75NTR in SCC-4 cells（both P=0.000）. Knock－out of p75NTR reversed proBNDF-induced SCC-4 cell migra－tion and invasion and reduced the mRNA expression levels of connective tissue growth factor（CTGF），vimentin（VIM），anex－elekto（AXL），high-mobility group A2（HMGA2），a disintegrin and metalloproteinase 19（ADAM19），fibronectin leucine-rich trans－membrane protein 2（FLRT2），and phosphodiesterase 1C（PDE1C）（all P<0.05）. Conclusion：ProBDNF promotes the migration and invasion of SCC-4 cells by up-regulating p75NTR expression，and its mechanism of action may be related to the up-regulation of the expression of downstream migration and invasion-promoting genes（namely，CTGF，VIM，AXL，HMGA2，ADAM19，FLRT2，and PDE1C） through the binding between proBDNF and p75NTR.