1. ¹Gene Vector Laboratory, Division of Cellular and Molecular Research, National Cancer Center, Singapore
2. ²Department of General Surgery, Singapore General Hospital, Singapore
3. ³Department of Pathology, Singapore General Hospital, Singapore
4. ⁴Department of Surgical Oncology, National Cancer Center, Singapore

Correspondence: Dr KM Hui, Division of Cellular and Molecular Research, National Cancer Center, 11 Hospital Drive, Singapore 169610, Singapore

⁵These authors contributed equally to this work

Received 21 January 2004; Accepted 9 September 2004; Published online 13 January 2005.

Abstract

A major challenge for gene therapy is to be able to deliver efficiently the gene of interest to specific cell types. Here we describe a safe and simple effective naked DNA gene delivery method, via inferior vena cava (IVC) injection, to the recipient's kidneys. It was further demonstrated that gene expression was concentrated in the proximal tubular epithelial cells of the cortico-medullary region of the kidney. Confocal microscopy analyses demonstrated the presence of the exogenous DNA in the renal cell membrane 10 min postgene delivery. However, it was only by 30 min that the presence of the exogenous DNA could be detected in the cell cytoplasm and in the nuclei of the renal cells. Stable expression of the -galactosidase gene could be detected for up to 35 days and no toxicity or any adverse pathological effect associated with the delivery method could be observed. Importantly, this IVC gene delivery method could promote the targeting of genes to carcinoma established in the kidney of SCID mice. These results provide the first evidence to support that stable gene expression could be achieved in the renal cells of kidney and the established carcinoma in the kidneys following in vivo gene delivery with naked DNA and could therefore provide the potential to design protocols for the gene therapy of the kidney diseases.