Over-expression of CD151 was found to be associated with metastasis and poor prognosis of prostatic carcinoma. This study was designed to examine the mechanism by which CD151 promotes the proliferation and migration of prostatic cancer cells. The pAAV-CD151, pAAV-GFP and pAAV-CD151-AAA mutant plasmids were constructed and used to transiently transfect PC3 cells （a prostatic carcinoma 3 cell line） by the mediation of Fugene HD. Then, the cells were assigned to control group, pAAV-GFP group, pAAV-CD151 group, and pAAV-CD151-AAA group respectively. Cell proliferation was evaluated by using the 3-[4,5-dimet-hylthiazol-2-yl]-2,5, diphenyltetrazolium bromide （MTT） method. Cell migration assay was performed by using Boyden chambers. The formation of CD151-integrin a3/a6 complex was determined by the method of co-immunoprecipitation. The protein expression levels of CD151 and extracellular signal-regulated kinase （ERK） were measured by Western blotting. The results showed that transfection of pAAV-CD151 or pAAV-CD151-AAA mutant increased the expression of CD151 protein in PC3 cells. Co-immunoprecipitation showed that more CD151-integrin a3/a6 complex was formed in the pAAV-CD151 group than in the control group, the pAAV-GFP group and the pAAV-CD151-AAA mutant group. Furthermore, the proliferative and migrating capacity of PC3 cells was substantially increased in the pAAV-CD151 group but inhibited in the pAAV-CD151-AAA mutant group. CD151 transfection increased the expression of phospho-ERK. Taken together, it was concluded that CD151 promotes the proliferation and migration of PC3 cells through the formation of CD151-integrin complex and the activation of phosphorylated ERK.
CD151 is a member of the tetraspanin family that is implicated as a promoter of pathological or physiological angiogenesis. C-Met is expressed on a variety of cells including vascular endothelial cells（VECs） and up-regulated during angiogenesis. In this study, we investigated whether CD151 regulated migration, proliferation, tube formation and angiogenesis of human umbilical VECs（HUVECs） with activation of C-Met. Moreover, we studied whether CD151 could affect the angiogenic molecules such as nitric oxide（NO）, vascular cell adhesion molecule-1（VCAM-1） and vascular endothelial growth factor（VEGF）. The expression of CD151 was determined by Western blotting. The cell proliferation assay was performed using the cell counting kit-8（CCK-8） method and cell migration was assessed in microchemotaxis chambers by using fetal bovine serum（FBS） as the chemotactic stimulus. The angiogenic molecules were evaluated using ELISA. The NO level was detected using NO detection kit. The potential involvement of various signaling pathways was explored using relevant antibodies. We found that proliferation, migration and tube formation of HUVECs were promoted by CD151 with activation of C-Met, FAK and CDC42, while they were suppressed with CD151 knockdown by RNAi. Similarly, the levels of NO, VCAM-1 and VEGF in HUVECs were increased by CD151, but they were inhibited with CD151 knockdown by RNAi. These data suggested that CD151 could promote migration, proliferation, tube formation and angiogenesis of HUVECs, which was possibly related to the C-Met signaling pathways.
