Prenyl Ammonium Salts--New Carriers for Gene Delivery: A B16-F10 Mouse Melanoma Model

Polyprenol-Based Lipofecting Agents for In Vivo Delivery of Therapeutic DNA to Treat Hypertensive Rats

Development of efficient vectors for transfection is one of the major challenges in genetic engineering. Previous research demonstrated that cationic derivatives of polyisoprenoids (PTAI) may serve as carriers of nucleic acids. In the present study, the effectiveness of two PTAI-based formulations (PTAI-6–8 and 10–14) was investigated and compared to the commercial reagents. The purpose of applied gene therapy was to enhance the expression of vascular endothelial growth factor (VEGF-A) in the renal medulla of spontaneously hypertensive rats (SHR) and to test its potential as a novel antihypertensive intervention. In the first part of the study (in vitro), we confirmed that PTAI-based lipoplexes efficiently transfect XC rat sarcoma cells and are stable in 37 °C for 7 days. In the in vivo experiments, we administered selected lipoplexes directly to the kidneys of conscious SHR (via osmotic pumps). There were no blood pressure changes and VEGF-A level in renal medulla was significantly higher only for PTAI-10–14-based formulation. In conclusion, despite the promising results, we were not able to achieve VEGF-A expression level high enough to verify VEGF-A gene therapy usefulness in SHR. However, results of our study give important indications for the future development of PTAI-based DNA carriers and kidney-targeted gene delivery.

Increased temperature-related adeno-associated virus vectors transduction of ovarian cancer cells - essential signatures of AAV receptor and heat shock proteins

Recombinant adeno-associated viruses (rAAVs) are becoming more commonly used in clinical trials involving gene therapy. Additionally AAV-based drugs have already been registered. Gene therapy aims to increase transduction efficiency, increase in vivo selectivity and reduce side effects. One approach to achieve this is the use of physical factors, such as temperature or more specifically, hyperthermia, which is already utilized in oncology. The aim of the present study was to investigate the effect of hyperthermic conditions (40°C and 43°C) on the rAAV transduction efficiency of ovarian cancer cells (Caov-3 and NIH:OVCAR-3) and non-cancerous cells (AAV-293). The present study was designed to identify functional associations between the level of gene transfer and the expression of representative genes for rAAV transmission (AAVR (AAV receptor), heparan sulfate proteoglycan (HSPG) 1 and HSPG2) and heat shock proteins (HSPs). The expressions of selected genes were measured via reverse transcription-quantitative PCR and cell adhesion/invasion chamber tests were also performed. The results revealed that ovarian cancer cell lines were more efficiently transduced with rAAV vectors at an elevated temperature. Additionally, the expression patterns of AAVR, HSPG1 and HSPG2 genes were different between the tested lines. The expression of certain receptors in ascites-derived NIH:OVCAR-3 ovarian cancer cells was higher compared with tumor-derived Caov-3 cells at 37, 40 and 43°C, which indicates a higher transduction efficiency in the formerly mentioned cells. Ascites-derived ovarian cancer cells were characterized by high expressions of HSP40, HSP90 and HSP70 families. Lower levels of HSP expression were demonstrated in less-effectively transduced Caov-3 cells. Furthermore, expressions of the examined genes changed with increasing temperature. The results indicated that temperature-dependent transduction is associated with the expression of the rAAV receptor and HSP genes. The results of the current study may aid the design of effective protocols for ovarian cancer gene therapy.

Innovative lipid-based carriers containing cationic derivatives of polyisoprenoid alcohols augment the antihypertensive effectiveness of candesartan in spontaneously hypertensive rats

Novel lipid-based carriers, composed of cationic derivatives of polyisoprenoid alcohols (amino-prenols, APrens) and 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE), were designed. The carriers, which were previously shown to be nontoxic to living organisms, were now tested if suitable for administration of candesartan, an antihypertensive drug. Spontaneously hypertensive rats (SHR) received injections of candesartan (0.1 mg/kg body weight per day; s.c.) in freshly prepared carriers for two weeks. The rats' arterial pressure was measured by telemetry. Urine and blood collection were performed in metabolic cages. In a separate group of SHR, the pharmacokinetics of the new formulation was evaluated after a single subcutaneous injection. The antihypertensive activity of candesartan administered in DOPE dispersions containing APrens was distinctly greater than that of candesartan dispersions composed of DOPE only or administered in the classic solvent (sodium carbonate). The pharmacokinetic parameters clearly demonstrated that candesartan in APren carriers reached the bloodstream more rapidly and in much greater concentration (almost throughout the whole observation) than the same drug administered in dispersions of DOPE only or in solvent. Serum creatinine (P_Cr) decreased significantly only in the group receiving candesartan in carriers with APrens (from 0.80 ± 0.04 to 0.66 ± 0.09 mg/dl; p < 0.05), whereas in the other groups P_Cr remained at the same level after treatment. Moreover, the new derivatives increased the loading capacity of the carriers, which is a valuable feature for any drug delivery system. Taken together, our findings led us to conclude that APrens are potentially valuable components of lipid-based drug carriers.

Effective usage of cationic derivatives of polyprenols as carriers of DNA vaccines against influenza virus

Background

Cationic derivatives of polyprenols (trimethylpolyprenylammonium iodides – PTAI) with variable chain length between 6 and 15 isoprene units prepared from naturally occurring poly-cis-prenols were tested as DNA vaccine carriers in chickens and mice. This study aimed to investigate if PTAI could be used as an efficient carrier of a DNA vaccine.

Methods

Several vaccine mixtures were prepared by combining different proportions of the vaccine plasmid (carrying cDNA encoding a vaccine antigen, hemagglutinin from H5N1 influenza virus) and various compositions of PTAI. The vaccines were delivered by intramuscular injection to either chickens or mice. The presence of specific antibodies in sera collected from the immunized animals was analyzed by enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition (HI) test.

Results

The mixtures of PTAI with helper lipids, such as DOPE (1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine), DC-cholesterol [{3ß-[N-(N′,N′-dimethylaminoethane)-carbamoyl] cholesterol} hydrochloride] or DOPC (1,2-dioleoyl-sn-glycero-3-phosphatidylcholine) induced strong humoral response to the antigen encoded by the DNA vaccine plasmid.

Conclusion

The animal immunization results confirmed that PTAI compositions, especially mixtures of PTAI with DOPE and DC-cholesterol, do work as effective carriers of DNA vaccines, comparable to the commercially available lipid transfection reagent.