Phytosphigosine-1-phosphate increases sensitivity of EGF-dependent cell proliferation.

The dermis is composed of dermal fibroblasts and various synthesized extracellular matrices. Proliferation of these cells is important to skin structure homeostasis. Therefore, human dermal fibroblasts (HDFs) growth factors have been previously evaluated. In the present study, we examined whether phytosphingosine-1-phosphate (PhS1P) regulates gene expression, particularly cell cycle-related genes. In addition, we investigated whether there was a synergistic effect of proliferation induced by PhS1P and epidermal growth factor (EGF) through PhS1P-regulated genes. A microarray approach was utilized to identify gene expression changes in PhS1P-treated HDFs and data were analyzed using gene ontology (GO). In addition, proliferative synergistic effects were measured using an MTT assay. The results showed that PhS1P regulates various genes, particularly cell cycle-related genes. Microarray data, followed by GO, indicated that PhS1P affected the biological processes involved in the cell cycle (cyclins A2, B1 and B2). Furthermore, these genes synergistically affected EGF-dependent proliferation. The results obtained in this study demonstrated that PhS1P altered gene expression profiles, inducing EGF-dependent cell proliferation. Therefore, PhS1p acts as a synergistic effector for EGF.