lipofectamine and Neoplasm-Metastasis

Gene-directed enzyme prodrug therapy (GDEPT) represents a technology to improve drug selectivity for cancer cells. It consists of delivery into tumor cells of a suicide gene responsible for in situ conversion of a prodrug into cytotoxic metabolites. Major limitations of GDEPT that hinder its clinical application include inefficient delivery into cancer cells and poor prodrug activation by suicide enzymes. We tried to overcome these constraints through a combination of suicide gene therapy with immunomodulating therapy. Viral vectors dominate in present-day GDEPT clinical trials due to efficient transfection and production of therapeutic genes. However, safety concerns associated with severe immune and inflammatory responses as well as high cost of the production of therapeutic viruses can limit therapeutic use of virus-based therapeutics. We tried to overcome this problem by using a simple nonviral delivery system.. We studied the antitumor efficacy of a PEI (polyethylenimine)-PEG (polyethylene glycol) copolymer carrying the HSVtk gene combined in one vector with granulocyte-macrophage colony-stimulating factor (GM-CSF) cDNA. The system HSVtk-GM-CSF/PEI-PEG was tested in vitro in various mouse and human cell lines, ex vivo and in vivo using mouse models.. We showed that the HSVtk-GM-CSF/PEI-PEG system effectively inhibited the growth of transplanted human and mouse tumors, suppressed metastasis and increased animal lifespan.. We demonstrated that appreciable tumor shrinkage and metastasis inhibition could be achieved with a simple and low toxic chemical carrier - a PEI-PEG copolymer. Our data indicate that combined suicide and cytokine gene therapy may provide a powerful approach for the treatment of solid tumors and their metastases.

Topics: Animals; Cations; Cell Line, Tumor; Cell Proliferation; Ganciclovir; Genetic Therapy; Genetic Vectors; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Internal Ribosome Entry Sites; Lipids; Lymph Nodes; Mice, Inbred C57BL; Neoplasm Metastasis; Neoplasms; Polyethylene Glycols; Polyethyleneimine; Polymers; Simplexvirus; Thymidine Kinase

This study aimed to investigate the relationship between miR-506 and proliferation and migration of breast cancer cells.. MiR-506 mimics, inhibitor, and negative control (NC) were transfected into MDA-MB-231 breast cancer cells. Cell proliferation, cell counting, colony formation assay, and Transwell assay were applied to evaluate the proliferation and migration of breast cancer cells. Data are shown as mean ± standard deviation and the experiment was performed 3 times. Statistical analyses were performed with SPSS version 10.0.. At 1 day after transfection, cell proliferation detected by CCK-8 assay was significantly promoted in miR-506 inhibitor when compared with the miR-506 mimics group and the NC group (P<0.05). At 3 days or 5 days after transfection, cell proliferation was markedly inhibited in the miR-506 mimics group, and miR-506 inhibitor was still significantly promoted. Cell counting with a hemocytometer showed similar results to cell proliferation. Colony formation assay showed that the number of colonies in the miR-506 mimics group was significantly smaller than that in the miR-506 inhibitor group and NC group. Transwell assay revealed that the number of migrated cells in miR-506 mimics was markedly smaller than that in the miR-506 inhibitor group and NC group.. MiR-506 over-expression significantly inhibits the proliferation, colony formation, and migration of breast cancer cells. miR-506 over-expression may thus be able to improve the malignant phenotype of breast cancer cells.

Topics: Breast Neoplasms; Cell Count; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; In Vitro Techniques; Lipids; MicroRNAs; Molecular Mimicry; Neoplasm Metastasis; Transfection; Tumor Stem Cell Assay

Small interfering RNA (siRNA) offers a great potential for the treatment of various diseases and disorders. Nevertheless, inefficient in vivo siRNA delivery hampers its translation into the clinic. While numerous successful in vitro siRNA delivery stories exist in reduced-protein conditions, most studies so far overlook the influence of the biological fluids present in the in vivo environment. In this study, we compared the transfection efficiency of liposomal formulations in Opti-MEM (low protein content, routinely used for in vitro screening) and human undiluted ascites fluid obtained from a peritoneal carcinomatosis patient (high protein content, representing the in vivo situation). In Opti-MEM, all formulations are biologically active. In ascites fluid, however, the biological activity of all lipoplexes is lost except for lipofectamine RNAiMAX. The drop in transfection efficiency was not correlated to the physicochemical properties of the nanoparticles, such as premature siRNA release and aggregation of the nanoparticles in the human ascites fluid. Remarkably, however, all of the formulations except for lipofectamine RNAiMAX lost their ability to be taken up by cells following incubation in ascites fluid. To take into account the possible effects of a protein corona formed around the nanoparticles, we recommend always using undiluted biological fluids for the in vitro optimization of nanosized siRNA formulations next to conventional screening in low-protein content media. This should tighten the gap between in vitro and in vivo performance of nanoparticles and ensure the optimal selection of nanoparticles for further in vivo studies.

Topics: Ascites; Cell Line, Tumor; Female; Genetic Therapy; Humans; Lipids; Liposomes; Nanoparticles; Nanotechnology; Neoplasm Metastasis; Ovarian Neoplasms; Particle Size; Proteins; RNA Interference; RNA, Small Interfering; Spectrometry, Fluorescence; Transfection

Sarcoma at advanced stages remains a clinically challenging disease. Interferons (IFNs) can target cancer cells by multiple antitumor activities, including the induction of cancer cell death and enhancement of immune response. However, the development of an effective cancer immunotherapy is often difficult, because cancer generates an immunotolerant microenvironment against the host immune system. An autologous hematopoietic stem cell transplantation (HSCT) is expected to reconstitute a fresh immune system, and expand tumor-specific T cells through the process of homeostatic proliferation. Here we examined whether a combination of autologous HSCT and IFNs could induce an effective tumor-specific immune response against sarcoma. First, we found that a type I IFN gene transfer significantly suppressed the cell growth of various sarcoma cell lines, and that IFN-β gene transfer was more effective in inducing cell death than was IFN-α in sarcoma cells. Then, to examine the antitumor effect in vivo, human sarcoma cells were inoculated in immune-deficient mice, and a lipofection of an IFN-β-expressing plasmid was found to suppress the growth of subcutaneous tumors significantly. Finally, the IFN gene transfer was combined with syngeneic HSCT in murine osteosarcoma models. Intratumoral IFN-β gene transfer markedly suppressed the growth of vector-injected tumors and inhibited formation of spontaneous lung and liver metastases in syngeneic HSCT mice, and an infiltration of many immune cells was recognized in metastatic tumors of the treated mice. The treated mice showed no significant adverse events. A combination of intratumoral IFN gene transfer with autologous HSCT could be a promising therapeutic strategy for patients with sarcoma.

Topics: Animals; Cell Line, Tumor; Female; Gene Transfer Techniques; Genetic Therapy; Hematopoietic Stem Cell Transplantation; Humans; Immunotherapy; Interferon-beta; Lipids; Mice; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Plasmids; Sarcoma, Experimental; Xenograft Model Antitumor Assays