title: Glioma cell growth inhibition following photochemical internalization enhanced non-viral PTEN gene transfection.
abstract: OBJECTIVE
  One of many limitations for cancer gene therapy is the inability of the therapeutic gene to transfect a sufficient number of tumor cells. Photochemical internalization (PCI) is a photodynamic therapy-based approach for improving the delivery of macromolecules and genes into the cell cytosol. The utility of PCI for the delivery of the GFP reporter gene on the same plasmid as a tumor suppressor gene (PTEN) was investigated in monolayers of U251 human glioma cells and muticell U87 glioma spheroids.
  
  
  METHODS
  U251 monolayers or U87 spheroids were incubated in AlPcS(2a) and non-viral vector polyplexes for 18 hours. In all cases, light treatment was performed with a diode laser at a wavelength of 670 nm. The non-viral transfection agents, branched polyethylenimine (bPEI), or protamine sulfate (PS), were used with the plasmid constructs GFP/PTEN or GFP.
  
  
  RESULTS
  PS/GFP polyplexes were much less toxic to the glioma cells compared to bPEI/GFP polyplexes but were highly inefficient at gene transfection if used alone. PCI resulted in a 5- to 10-fold increase in GFP protein expression compared to controls. PCI-bPEI/PTEN or PCI-PS/PTEN transfection of either U251 monolayers or U87 spheroids significantly inhibited their growth. but had no effect on MCF-7 cells containing a wild-type PTEN gene. In addition PCI-GFP transfection of gliomas cells had no effect on their growth pattern.
  
  
  CONCLUSIONS
  Collectively, the results suggest that AlPcS(2a) -mediated PCI can be used to enhance cell growth inhibition via transfection of tumor suppressor genes in glioma cells containing mutant PTEN genes.
authors.affiliation: Department of Neurosurgery, University of California, Irvine, California, USA. mmathews@uci.edu
authors.forename: Marlon S
authors.initials: MS
authors.lastname: Mathews
authors.forename: En-Chung
authors.initials: EC
authors.lastname: Shih
authors.forename: Genesis
authors.initials: G
authors.lastname: Zamora
authors.forename: Chung-Ho
authors.initials: CH
authors.lastname: Sun
authors.forename: Soo Kyung
authors.initials: SK
authors.lastname: Cho
authors.forename: Young Jik
authors.initials: YJ
authors.lastname: Kwon
authors.forename: Henry
authors.initials: H
authors.lastname: Hirschberg
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D015316:Genetic Therapy / Q000379:methods*; D005909:Glioblastoma / Q000235:genetics / Q000628:therapy*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D007211:Indoles / Q000627:therapeutic use; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D009942:Organometallic Compounds / Q000627:therapeutic use; D051059:PTEN Phosphohydrolase / Q000235:genetics*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011094:Polyethyleneimine; D011479:Protamines; D014162:Transfection / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor; D007211:Indoles; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D011479:Protamines; D049452:Green Fluorescent Proteins; C064331:aluminum phthalocyanine disulfonate; D011094:Polyethyleneimine; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human