An ultrasonic nanobubble-mediated PNP/fludarabine suicide gene system: A new approach for the treatment of hepatocellular carcinoma

• Published in: PloS one Vol. 13; no. 5; p. e0196686
• Main Authors: Zhang, Bo, Chen, Mingna, Zhang, Youming, Chen, Wei, Zhang, Lihua, Chen, Lv
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02.05.2018; Public Library of Science (PLoS)
• Subjects: Apoptosis; Biology and Life Sciences; Blood lipids; Care and treatment; Cell survival; Cytotoxicity; Escherichia coli; Fludarabine; Gene expression; Gene therapy; Health aspects; Hepatocellular carcinoma; Homogeneity; Irradiation; Liver cancer; Medicine and Health Sciences; Membrane lipids; Phosphocholine; Phospholipids; Phosphorylase; Research and Analysis Methods; Suicidal behavior; Suicide; Suicide genes; Ultrasonic testing; Ultrasound; United Kingdom > UK; United States > US; China; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0196686

The purpose of this study is to generate an ultrasonic nanobubble (NB)-mediated purine nucleoside phosphorylase (PNP)/fludarabine suicide gene system for the treatment of human hepatocellular carcinoma (HCC). NBs were prepared from a mixture the phospholipids 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphate (DPPA), perfluoropropane gas and other materials using the high shear dispersion method. NBs treated with ultrasound irradiation functioned as a gene-transfer system, and a self-constructed suicide gene expression plasmid, pcDNA3.1(+)/PNP, treated with fludarabine functioned as a therapeutic gene. This system was used to determine the cytotoxic effects of PNP/fludarabine on HepG2 cells and SMMC7721 cells. 1. NBs with a small diameter (208-416 nm) and at a high concentration and fine homogeneity were prepared under the optimal method. 2. The pcDNA3.1(+)/PNP plasmid was efficiently transfected into HCC cells using ultrasonic NBs. 3. At 0.75μg/ml fludarabine, PNP/fludarabine showed marked cytotoxic effects toward HepG2 and SMMC7721 cells. PNP/fludarabine achieved the same effect against both SMMC7721 and HepG2 cells but at a lower concentration of fludarabine for the latter. 4. Bystander effects: a 10-20% decrease in the cell survival rate was observed when only 5-10% of transfected cells were PNP positive. NBs constitute a non-toxic, stable and effective gene-delivery platform. The PNP/fludarabine suicide gene system inhibited the growth of HCC cells, induced HCC cell apoptosis, and caused a notable bystander effect at a low fludarabine concentration. This study establishes an important new method for miniaturizing microbubbles and improving a new NB-mediated approach for gene therapy of HCC.