title: A novel cell-permeable RDP-p53 fusion protein for specific inhibition on the growth of cancerous neural cells.
abstract: OBJECTIVE
  There is 25-35% mutation rate of p53 in cancerous neural cells and this rate reaches 70-76% in glioma cell line. Complement of wild-type p53 has become a potential strategy for protein therapy of cancerous neural cells. Here we investigated the feasibility of a novel RDP-p53 fusion protein for anti-proliferation of cancerous neural cell and the possible mechanism, which would provide an effective approach for targeted delivery of p53 protein to treat cancerous neural cells.
  
  
  METHODS
  The RDP-p53 fusion proteins are expressed in Escherichia coli, and they are labeled with FITC and rhodamine B by chemical modification. The fluorescence-labeled proteins are added to human hepatocellular carcinoma cells (HepG-2) and human neuroblastoma cells (SH-SY5Y) in order to investigate the possibility of RDP enhancing the cell uptake efficiency into neural cells as a cell-permeable carrier. The inhibitory effect of RDP-p53 on SH-SY5Y and human glioma cells (U251) was evaluated by MTT assay. Moreover, the anti-proliferation mechanism of RDP-p53 was determined by Apoptosis and Necrosis Assay Kit and flow cytometric analysis.
  
  
  RESULTS
  The results showed that RDP-p53 could enter SH-SY5Y cells with high efficiency and selectively inhibit the growth of cancerous neural cells, including SH-SY5Y and U251. Also, cell apoptosis pathway and cell-cycle arrest at the G2/M phase were associated with the inhibition mechanism of RDP-p53 according to the data of flow cytometric analysis.
  
  
  CONCLUSIONS
  RDP-p53 could be a novel antitumor candidate for targeting treatment of cancerous neural cells.
authors.affiliation: a School of Pharmaceutical Sciences, Southwest University , Chongqing , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.affiliation: a School of Pharmaceutical Sciences, Southwest University , Chongqing , China.
authors.forename: Enqi
authors.initials: E
authors.lastname: Zhang
authors.affiliation: a School of Pharmaceutical Sciences, Southwest University , Chongqing , China.
authors.forename: Ailing
authors.initials: A
authors.lastname: Fu
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D005910:Glioma / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D009447:Neuroblastoma / Q000737:chemistry / Q000188:drug therapy* / Q000378:metabolism; D010539:Permeability; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D016159:Tumor Suppressor Protein p53
keywords: Cancerous neural cells; RDP-p53; cell apoptosis; cell cycle; cell uptake