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.

Keywords:

• Cancerous neural cells
• cell apoptosis
• cell cycle
• cell uptake
• RDP-p53

Declaration of interest

The authors report that they have no conflicts of interest regarding the publication of this paper. This work is supported by the grants from the Natural Science Foundation of China (81273416).