Expression of Rho GTPases family in melanoma cells and its influence on cytoskeleton and migration

Rho GTPases family members influenced the filopodia, lamellipodia, stress fiber and adhesion plaque of melanoma cells through regulating cytoskeleton recombination. The role of Rho GTPases family in the migration and invasion of melanoma and its molecular mechanism were explored. The morphological difference between three types of melanoma cells (M14, A375 and MV3) and human melanocyte (MC) was observed by the Hoffman microscope. Cells were stained by phalloidin labeled by rhodamine. The differences between 4 types of cells in filopodia, lamellipodia, stress fiber and adhesion plaque (microfilament is the main constituent) were observed under the super-high resolution microscope. The migration ability of 4 types of cells was detected by Transwell migration assay. QPCR was used to detect the mRNA transcription level of Rho GTPases family. WB was adopted to detect the expression of RhoD and DIAPH2 proteins. There were significant differences in filopodia, lamellipodia, stress fiber and adhesion plaque between MC and 3 types of melanoma cells (M14, A375 and MV3). MC did not have stress fiber or adhesion plaque, while M14, A375 and MV3 had stress fiber and adhesion plaque. All 4 types of cells had thin and short filopodia. MV3 had fewer but thicker stress fibers than the latter two. Transwell migration test indicated the followings: M14 and A375 had a similar high migration rate; the migration rate of MV3 was slightly low; MC did not have the ability of transmembrane migration. QPCR results of Rho GTPases family in 4 types of cells showed the change corresponding to immunofluorescence. WB results showed that RhoD was barely expressed in M14, A375 or MV3. DIAPH2, the downstream effector molecule of RhoD, had the corresponding change. Rho GTPases influences the migration and invasion of melanoma cells through regulating filopodia, lamellipodia, stress fiber and adhesion plaque (microfilament is the main constituent).