Gene transfer for the esophagus -- an ex vivo study demonstrating transfected gene expression in the human esophagus.

Background and Objectives: Esophageal cancer has one of the worst prognoses of all cancers, mainly due to its aggressive growth pattern and late presentation. Using radiotherapy, chemotherapy, or even surgery it is only possible to cure a small minority and so alternative strategies need to be evaluated. In this study we aim to investigate the feasibility of using liposomes to transfect genes into human esophageal biopsies at high enough levels to achieve a biological effect.Methods: Human esophageal biopsies were transfected with constructs encoding Green Fluorescent Protein or human wild type p53. Expression of Green Fluorescent Protein within these samples was determined by FACScan analysis and confocal microscopy, whereas p53 expression was assessed by Western blotting and Reverse Transcriptase Polymerase Chain Reaction, probing for p53 and a downstream effector WAF1/p21.Results: Confocal microscopy verified the expression of Green Fluorescent Protein in human esophageal biopsies in cells 7 to 10 layers deep. Green Fluorescent Protein expression has also been demonstrated by FACScan analysis. The successful introduction and expression of wild type p53 has been shown in normal esophageal biopsies by Western blotting and RT-PCR and in Barrett's esophageal biopsies by Western blotting alone. In addition, we have demonstrated an increase in the expression of WAF1/p21 in 50% of biopsies transfected with p53.Conclusion: Liposome-mediated transfer of genes into human esophageal cells is feasible and can be performed at a sufficient dose to achieve expression of downstream genes. [ABSTRACT FROM AUTHOR]