Increased uptake of liposomal–dna complexes by lung metastases following intravenous administration

Abstract

We have investigated the effects of an improved liposomal formulation (extruded DOTAP:cholesterol (DOTAP:Chol)-DNA complex) on transgene expression in tumor cells and normal cells of murine and human origin both in vitro and in vivo. In vitro, transgene expression was significantly increased (P = 0.01) in human tumor cells compared to normal human cells. The increased transgene expression was due to increased uptake of the liposome-DNA complex by tumor cell phagocytosis. Furthermore, immunohistochemical analysis demonstrated a greater transgene expression in lung tumors than in surrounding normal tissues. Increased transgene expression due to enhanced uptake of the liposome-DNA complexes by tumor cells in vivo was also demonstrated using fluorescently labeled DOTAP:Chol liposomes. Finally, evaluation of lung tissue explants obtained from patients undergoing pulmonary resection demonstrated significantly higher (P = 0.001) transgene expression in tumor cells than in normal cells. Thus, we demonstrated that intravenous injection of DOTAP:Chol-DNA complex results in increased transgene expression in tumor and is due to increased phagocytosis of the complexes by tumor cells.

Liposomal vector mediated delivery of the 3p FUS1 gene demonstrates potent antitumor activity against human lung cancer in vivo

“…16,17 Synthesis of liposomes and preparation of DNA:liposome complex An amount of 20 mM DOTAP:Chol liposome was synthesized and extruded through Whatman Filters (Kent, UK) of decreasing size (1.0, 0.45, 0.2, and 0.1 mm) as described previously. 17,18 For preparation of DNA:liposome complexes DOTAP:Chol (20 mM) stock solution and DNA solution diluted in 5% dextrose in water (D5W) were mixed in equal volumes and mixed to give a final concentration of 4 mM DOTAP:Chol-150 mg DNA in 300 ml final volume (ratio 1:2.6) as described previously. 17 The DNA:liposome mixture thus prepared was used in all the experiments described in the present study.…”

“…16 Using DO-TAP:Chol liposome, we have previously demonstrated effective gene delivery of tumor suppressor genes to subcutaneous and disseminated lung metastasis resulted in a therapeutic efficacy. 17,18 In addition, systemic injection of DOTAP:Chol-DNA complex demonstrated no significant organ-related toxicity. These results demonstrated DOTAP:Chol liposome to be an ideal vector for systemic delivery of therapeutic genes.…”

Induction of tumor inhibition and apoptosis by a candidate tumor suppressor gene DRR1 on 3p21.1

“…The cationic liposomes consisting of N-[1-(2,3-dioleoyloxy)-propyl]-N,N,N-trimethylammonium methylsulfate (DOTAP) and cholesterol (Chol) were prepared for in vivo delivery of plasmid DNA by our laboratory as described (7). DOTAP:Chol liposomes proved to be a good non-viral vehicle for the delivery of plasmids efficiently in vivo and were shown to achieve effective levels of trans-gene expression in highly vascularized tissues, such as tumors or the lung (8,9).…”

International progress in cancer gene therapy

“…10 Preclinical results where the systemic delivery of the FUS1 gene encapsulated in DOTAP-cholesterol lipid-based nanoparticles reduced lung metastasis and increased animal survival. [11][12][13] On the basis of these preclinical studies, FUS-nanoparticle-based systemic therapy in a phase I clinical trial for human nonsmall-cell lung cancer patients has been initiated by Rajagopal Ramesh (MD Anderson Cancer Centre, USA). This is the first systemic nanoparticle-based cancer cancer gene therapy clinical trial in the world and the trial has now achieved preliminary results on the first 13 patients who have received FUS1-nanoparticle treatment.…”