Gene delivery to oral cancer cells by lipid-DNA complexes containing human serum albumin


Nejat Düzgüneş: 0000-0001-6159-1391


Biomedical Sciences

Document Type

Conference Presentation

Conference Title

32nd Annual Meeting of the American Association for Dental Research


San Antonio, TX

Conference Dates

March 12-15, 2003

Date of Presentation


Journal Title

Journal of Dental Research

Journal ISSN


Journal Volume Number

82 (special issue A)

First Page



Objectives: Oral squamous cell carcinoma (OSCC) is the most prevalent cancer involving the oral cavity and oropharynx. Our long-term goal is to deliver therapeutic genes for the treatment of OSCC. Cationic lipid-DNA complexes (lipoplexes) are used as vectors for gene delivery both in vitro and in vivo. Since serum inhibits gene transfer by lipoplexes, we examined whether DNA complexed with the cationic lipid reagent Escort and human serum albumin could transfect human SCC cells (HSC-3) in the presence of fetal bovine serum (FBS), as observed for other types of cells. Methods: Cells were transfected with the luciferase-expressing plasmid, pCMVluc, complexed with either DOTAP/DOPE (Escort) or Escort + Albumin (“EA”) in the presence of increasing concentrations of FBS. Efficiency of transfection was determined as luciferase activity, expressed as relative light units (RLU)/ml of cell lysate. Cells transfected with the pCMV.HSV-tk plasmid expressing Herpes Simplex Virus thymidine kinase were treated with ganciclovir. Cell viability was quantified by the Alamar Blue assay. Results: Albumin enhanced Escort-mediated transfection. EA-mediated transfection was inhibited by serum in a dose-dependent manner. Lipoplexes with a 2:1 (+/-) charge ratio were more resistant to the effect of serum than those with either a 1:1 or 4:1 (+/-) charge ratio. In the absence of serum, the delivery of the HSV-tk gene to HSC-3 cells by plain Escort and EA lipoplexes, followed by ganciclovir treatment for 7 days, resulted in >70% and >90% cytotoxicity, respectively. The cytotoxic effect of HSV-tk plasmid was completely abolished when 10% FBS was present during Escort- or EA-mediated transfection. Conclusions: (i) Escort-mediated transfection can be enhanced by albumin; (ii) complexation of Escort with albumin does not overcome the inhibitory effects of serum on HSV-tk-mediated cytotoxicity in HSC-3 cells; and (iii) additional non-viral vectors should be tested for resistance to the inhibitory effect of serum.

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