NT-polyplex: a new tool for therapeutic gene delivery to neuroblastoma tumors

Abstract

and 4 Molecular and Steroid hormones, Neurotensin and Tumor Progression INSERM UPMC Cdr Saint-Antoine Eq 7, Paris, France Neurotensin (NT)-polyplex is a nonviral system for the targeted gene delivery to cells that express and internalize the high-affinity NT receptor (NTSR1). In hemiparkinsonian rats, we previously demonstrated the morphological and functional recovery from dopaminergic neurodegeneration using the NT-polyplex as a vehicle to transfect a neurotrophic gene. The main objective of this work was to demonstrate the feasibility of NT-polyplex to transfect reporter or therapeutic genes into neuroblastoma tumors through the blood stream or by intratumoral injection. N1E-115 cells known to express NTSR1 were allografted into athymic mice to generate the neuroblastoma tumor model. Both routes of administration allowed the NT-polyplex to reach and transfect tumoral cells. A low transgene expression was also detected in intestinal tract cells only after the injection into the blood stream. The transfection of the thymidine kinase (HSVTK) suicide gene followed by ganciclovir (GCV) treatment decreased the size and weight of neuroblastoma tumors by 30-50% and increased apoptosis compared to controls. This study shows the potential of the NTpolyplex as specific gene-transfer system for NTSR1 cancer cells.

Suicide HSVtk Gene Delivery by Neurotensin-Polyplex Nanoparticles via the Bloodstream and GCV Treatment Specifically Inhibit the Growth of Human MDA-MB-231 Triple Negative Breast Cancer Tumors Xenografted in Athymic Mice

“…However, the feasibility of this approach as a treatment for previously established NTSR1 (+) cell tumors remains unknown. Interestingly, NTSR1 internalization, which is overactive in cancer cells [11], has become an efficient pathway to introduce therapeutic genes that are intravenously delivered by the NTS-polyplex nanoparticles as we previously demonstrated in a murine neuroblastoma model [24].…”

“…Apoptosis, which was induced by HSVtk expression and GCV treatment, was evaluated in MDA-MB-231 cells using indirect immunofluorescence (caspase-3 activation) [45], [46] and Apostain assays (apoptotic bodies) [45] in vitro and in vivo . Cultured cells and tissues were processed as previously described [24], [45], [46]. The immunofluorescence staining was performed using the following primary antibodies: a goat polyclonal antibody against NTSR1 (1∶100; Santa Cruz Biotechnology; Santa Cruz, CA, USA) and a rabbit polyclonal antibody against cleaved caspase-3 (1∶400 for in vitro and 1∶150 for in vivo ; Cell Signaling Technology; Beverly, MA, USA).…”

“…The internalization and expression assays of NTS-polyplex nanoparticles harboring the plasmid pEGFP-N1 were performed after an injection into tumors at a flow rate of 10 µL/min using a micropump Model MD 1001 (Bionanalytical System Inc.; West Lafayette, IN, USA) or an injection in the bolus via the retro-ophthalmic vein [24]. For the internalization assays, tumors were dissected 6 h after the local injection or 24 h after the intravenous injection of propidium iodide-labeled NTS-polyplex nanoparticles harboring the plasmid pEGFP-N1 [25], [29], [31] as described elsewhere [24].…”

“…The neurotensin (NTS)-polyplex consists of synthetic nanoparticles that can transfer plasmid DNA (pDNA) encoding any gene of interest into cells that express and internalize the NTSR1, including dopaminergic neurons [25]–[28] and cancer cells [24], [29]. The NTS-polyplex nanoparticles result from the compaction of a pDNA via the electrostatic binding of the Vp1 SV40 karyophilic peptide (KP) and the NTS-carrier, which is a conjugate of poly-L-lysine (PLL), NTS, and the hemagglutinin-derived HA2 fusogenic peptide (FP) [25], [30].…”

“…A recent study has demonstrated that the intravenous injection of NTS-polyplex nanoparticles, which are composed of the herpes simplex virus thymidine kinase (HSVtk) gene, and the complementary treatment with ganciclovir (GCV) inhibit the growth of murine neuroblastoma tumors that are allografted in athymic mice [24]. The HSVtk-GCV system is one of the most efficient approaches to cause cell death in rapidly dividing cells [37].…”