A putative novel protein,DEPDC1B,is overexpressed in oral cancer patients,and enhanced anchorage-independent growth in oral cancer cells that is mediated by Rac1 and ERK

Background: the dep domain is a globular domain containing approximately 90 amino acids,which was first discovered in 3 proteins: drosophila disheveled,caenorhabditis elegans egl-10,and mammalian pleckstrin; hence the term,dep. depdc1b is categorized as a potential rho gtpase-activating protein. the function of the dep domain in signal transduction pathways is not fully understood. the depdc1b protein exhibits the characteristic features of a signaling protein,and contains 2 conserved domains (dep and rhogap) that are involved in rho gtpase signaling. small gtpases,such as rac,cdc42,and rho,regulate a multitude of cell events,including cell motility,growth,differentiation,cytoskeletal reorganization and cell cycle progression.results: in this study,we found that it was a guanine nucleotide exchange factor and induced both cell migration in a cultured embryonic fibroblast cell line and cell invasion in cancer cell lines; moreover,it was observed to promote anchorage-independent growth in oral cancer cells. we also demonstrated that depdc1b plays a role in regulating rac1 translocated onto cell membranes,suggesting that depdc1b exerts a biological function by regulating rac1. we examined oral cancer tissue; 6 out of 7 oral cancer tissue test samples overexpressed depdc1b proteins,compared with normal adjacent tissue.conclusions: depdc1b was a guanine nucleotide exchange factor and induced both cell migration in a cultured embryonic fibroblast cell line and cell invasion in cancer cell lines; moreover,it was observed to promote anchorage-independent growth in oral cancer cells. we also demonstrated that depdc1b exerts a biological function by regulating rac1. we found that oral cancer samples overexpressed depdc1b proteins,compared with normal adjacent tissue. suggest that depdc1b plays a role in the development of oral cancer. we revealed that proliferation was linked to a novel depdc1b-rac1-erk1/2 signaling axis in oral cancer cell lines. © 2014 su et al.; licensee biomed central.