Gene Therapy Engineering Research Articles

The therapeutic potential of genome editing for β-thalassemia

The rapid advances in the field of genome editing using targeted endonucleases have called considerable attention to the potential of this technology for human gene therapy. Targeted correction of disease-causing mutations could ensure lifelong, tissue-specific expression of the relevant gene, thereby alleviating or resolving a specific disease phenotype. In this review, we aim to explore the potential of this technology for the therapy of β-thalassemia. This blood disorder is caused by mutations in the gene encoding the β-globin chain of hemoglobin, leading to severe anemia in affected patients. Curative allogeneic bone marrow transplantation is available only to a small subset of patients, leaving the majority of patients dependent on regular blood transfusions and iron chelation therapy. The transfer of gene-corrected autologous hematopoietic stem cells could provide a therapeutic alternative, as recent results from gene therapy trials using a lentiviral gene addition approach have demonstrated. Genome editing has the potential to further advance this approach as it eliminates the need for semi-randomly integrating viral vectors and their associated risk of insertional mutagenesis. In the following pages we will highlight the advantages and risks of genome editing compared to standard therapy for β-thalassemia and elaborate on lessons learned from recent gene therapy trials.

Abstract 3195: STAT3 inhibition using shRNA inhibits GBM proliferation, cell migration, anchorage-independent growth of mouse, rat, and human stem-like cells in vitro; and it induces long term survival and anti-GBM immunity in vivo

Abstract The purpose of this study was to elucidate the role of Signal Transducers and Activators of Transcription 3 (STAT3) signaling on the tumor microenvironment in the most commonly occurring and aggressive primary brain tumor, Glioblastoma Multiforme (GBM), including preclinical testing of inhibition of STAT3 expression in vivo in syngeneic and patient derived xenograft (PDX) models of GBM. GBM is genetically heterogeneous, but always overexpresses genes that are vital to cell cycle regulation, cell growth and proliferation, cell invasion, and angiogenesis. STAT proteins are transcription factors associated with gene regulation and expression signatures that are implicated in several survival pathways that enable human GBMs to grow in the brain parenchyma. In addition, STAT3 has been identified as a central mechanism in tumor-induced immunosuppression in GBM and other cancers. We studied the effects of STAT3 inhibition via shRNA down-regulation in vivo and in vitro using patient derived primary glioma cells (HF2303 & MGG8) in conjunction with other glioma lines from humans, mice, and rats (U251, GL26, and CNS-1, respectively). In this study, we found that GBM cells harboring down-regulated STAT3 signaling exhibit delayed proliferation, increased apoptosis, and anchorage independence. In vivo, STAT3 inhibition resulted in increased survival rates when tumor cells were treated with the STAT3 shRNA both pre- and post-GBM implantation (syngeneic GBM model). Our data demonstrate that STAT3 has a profound influence on the GBM microenvironment, which prevents the host from clearing the tumor. Down-regulating this signaling pathway using gene therapeutic strategies allows for infiltration of immune cells, decreased invasion, and a decrease in GBM cells’ proliferation that leads to the tumor elimination in ∼83% of the animals, this was associated with the development of an effective anti-tumor immunity that prevents tumor recurrence. Given the phenotype of STAT3 inhibition in in vitro assays and its success in in vivo GBM models, inhibition of STAT3 expression using shRNA and gene therapy technologies constitutes an attractive strategy for preclinical development as a potent therapeutic target for GBM. Citation Format: Nathan T. VanderVeen, Nicholas Raja, Elizabeth Yi, James Curtin, Peter Chockley, Hikmat Assi, Jonathan Savakus, Tom Mikkelsen, Samuel Rabkin, Pedro R. Lowenstein, Maria G. Castro. STAT3 inhibition using shRNA inhibits GBM proliferation, cell migration, anchorage-independent growth of mouse, rat, and human stem-like cells in vitro; and it induces long term survival and anti-GBM immunity in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3195. doi:10.1158/1538-7445.AM2015-3195

Advanced T-Cell Engineering for Cancer Therapy (ATECT).

Human Gene Therapy Clinical DevelopmentVol. 26, No. 2 European Commission Project SummariesOpen AccessAdvanced T-Cell Engineering for Cancer Therapy (ATECT)Published Online:18 Jun 2015https://doi.org/10.1089/humc.2015.2520AboutSectionsPDF/EPUB ToolsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail Contract No.: 602239; EU contribution: € 5,931,151; Total costs: € 7,780,342.20; Starting date: 01/12/2013; Duration: 60 monthsBackground and ObjectivesT-effector cells (T-cells) are immune cells whose major role is surveillance for and destruction of virally infected cells. T-cells can be readily isolated from peripheral blood of patients or normal donors and cultured in vitro. By ex vivo manipulation, T-cells that recognize a specific cancer antigen can be selected and administered as a therapeutic. This therapy, known as adoptive immunotherapy, is an established method for treating a small group of human cancers, but is limited by an inability to generate T-cells specific for a wider range of cancer antigens.More recently, gene therapy technology has provided a radically different strategy: by introducing a coding sequence for a chimeric antigen receptor (CAR) or a native T-cell receptor (TCR) using an integrating vector, we can rapidly confer any specificity to a large T-cell population in vitro. We and others have tested such “positive” engineering in T-cells as a cancer therapeutic with clear and, in some cases, dramatic results.Despite the considerable advance afforded us by genetic engineering, considerable barriers still exist, holding back the full potential of adoptive immunotherapy with engineered T-cells.At present, a bespoke autologous therapeutic product must be produced for each patient. We believe that this limits practicality and scalability, restricting CARs to an experimental therapy in few specialized centers worldwide. Further, a lag time of weeks is needed for T-cell product generation. Production may fail or may be qualitatively different between patients. Recent success with B-cell malignancy represents the “low-hanging fruits” of CAR therapy. The problem of targeting other antigens, recruiting sufficient T-cells to sites of disease, and a hostile microenvironment are considerable barriers to function in broader range of human cancers, in particular solid tumors.Recent genome engineering methods now give us an additional powerful T-cell engineering strategy to use alongside integrating vectors: Custom endonucleases targeting arbitrary sequences can result in inactivation of any desired genes—“negative” gene therapy. The transcription activator-like effector nuclease (TALEN) technology is emerging as the most robust and effective technology platform for genomic engineering. We propose to develop advanced T-cell gene therapy with a combination of “positive” and “negative” engineering strategies, which we believe will revolutionize cellular therapy. Not only can we now engineer T-cells to have any specificity, but also we can render them resistant to hostile microenvironment and immunosuppressive agents and confer new properties. In addition, this combination of engineering strategies opens up the possibility of generating universal or “off-the-shelf” T-cells that will facilitate effective commercialization of T-cell therapy.The core aim of this consortium is to test advanced T-cell therapy in early clinical studies and continue to develop it in the laboratory. We will first establish the feasibility and safety of the approach in a simple phase I study of TCR-edited, CD19 CAR donor T-cells in allogeneic hematopoietic stem cell transplantation. We will build on this study to a second phase I study, testing a more elaborate strategy to develop universal CAR T-cells that can be mass-produced and given “off the shelf.” In addition, we will perform developmental and preclinical work, which we believe is necessary to expand the scope of engineered T-cells to more challenging malignancies by exploiting gene-editing technology.Approach and MethodologyWe will implement clinical studies of CAR T-cells in patients with relapsed/refractory B-cell cancers. In addition to the use of lentiviral vectors to modify the T-cells, T-cell products will be subjected to genome editing to prevent allogeneic effects. In addition to this, more basic research and development will be applied to exploiting this concept of combining lentiviral engineering with genome editing for enhanced adoptive immunotherapy.Main FindingsNone reported yet.Expected OutcomeTwo complementary clinical studies of CD19-directed CAR therapy that together explore the potential and challenges for “off-the-shelf” CAR T-cell therapy. Development of new approaches to enhance adoptive immunotherapy by genome editing of T-cell products.Major PublicationsNone reported yet.© European Union 2015. Published by Mary Ann Liebert, Inc.FiguresReferencesRelatedDetails Volume 26Issue 2Jun 2015 InformationCopyright 2015, Mary Ann Liebert, Inc.To cite this article:Advanced T-Cell Engineering for Cancer Therapy (ATECT).Human Gene Therapy Clinical Development.Jun 2015.78-78.http://doi.org/10.1089/humc.2015.2520creative commons licensePublished in Volume: 26 Issue 2: June 18, 2015PDF download

Transposon-Based, Targeted Ex Vivo Gene Therapy to Treat Age-Related Macular Degeneration (TargetAMD).

Transposon-Based, Targeted Ex Vivo Gene Therapy to Treat Age-Related Macular Degeneration (TargetAMD).

180. TARGT™ Shows Sustained Secretion of the Therapeutic Peptide GLP-2 Which Retains Functional Activity in SCID Mice and Rats

Glucagon-like peptide-2 (GLP-2) is a naturally occurring 33 amino acid peptide, with t1/2 of 6-7 min. This peptide is produced by L cells of small intestine and has several important functions, such as increasing intestinal absorption, stimulating intestinal growth, reducing bone breakdown and impacting gastric and intestinal motility. It is well known that individuals with short bowel syndrome benefit from exogenous GLP-2 to improve intestinal absorption.Native peptides have been difficult to develop into drugs because of their short half-life, poor metabolic stability and rapid clearance. Manufactured peptides frequently require structural modification and, long-acting formulations. Moreover, the treatment with such peptides frequently uses high doses, which can lead to off-target effects such as nausea and vomiting in some patients. As an alternative, we developed a novel approach that allows our TARGT™ (Transduced Autologous Restorative Gene Therapy) technology to produce and secrete peptides such as GLP-2.The TARGT™ system is an ex-vivo gene therapy, which we have now demonstrated is capable of providing autologous, continuous peptide therapies, at physiological ranges. Our group previously demonstrated such findings for certain proteins. In one set of experiments described herein, the TARGT™ system consists of several 2 × 30 mm biopsies of dermal tissue (Micro-Organ, MO), extracted under local anesthetic followed by fibroblast transduction with a Helper-Dependent Adenoviral Vector (HDAd) containing a novel GLP-2 gene expression cassette. After culture, and measurement of peptide production, one or more transduced MOs (TARGTs™) are re-implanted into the patient as required to achieve the desired dose. The system allows dose flexibility and the TARGTs™ may be added or removed according to in-vivo secretion levels.Pre-clinical studies, using this novel technology, showed GLP-2 TARGT (TARGTGLP-2) in-vitro secretion levels of tens of micrograms per day. Preliminary data from in-vivo SCID mice experiments confirms that TARGT-secreted human GLP-2 analog reaches the mouse blood stream and exhibits a sustained secretion profile similar to tho se observed and reported with other proteins using the TARGT™ technology (e.g. EPO, IFNα). In addition, in-vivo SCID mice and rat experiments suggest that TARGT™ secreted GLP-2 analog is active, and increases intestinal villous height and intestinal crypt cell proliferation rate.Data obtained so far suggests that TARGTGLP-2 may provide a favorable PK profile and physiologic levels of continuous GLP-2 for extended periods of time, avoiding supra-physiological peak serum concentration and achieving continuous coverage with less exposure compared to exogenous GLP-2 injections. The current results suggest that the TARGT™ platform is a promising novel therapy for short bowel syndrome and potentially other diseases of endogenous protein/peptide deficiency.

P27kip1 overexpression regulates VEGF expression, cell proliferation and apoptosis in cell culture from eutopic endometrium of women with endometriosis.

We hypothesized that p27(kip1) overexpression can regulate endometriosis cell proliferation, apoptosis and vascular endothelial growth factor (VEGF) expression in the endometrium. The overexpression of p27(kip1) was obtained by transduction of p27(kip1) in primary cultures of endometrium obtained from women with endometriosis tissue with gene therapy technology. First generation bicistronic adenovirus: AdCMVhp27IRESEGFP (Adp27) and AdCMVNull (AdNull) were engineered in order to induce p27(kip1) expression in endometrial cells primary culture. The effect of p27(kip1) overexpression was elucidated through the cell proliferation evaluation and the expression of the cell cycle-related proteins p16, p21, p27, and p53. Cell cycle and apoptosis in endometrial cells from women with and without endometriosis were also evaluated. The VEGF levels were evaluated 1 and 7 days after transduction. The experiments were performed using Immunofluorescence stainings and flow cytometry technique. The cell proliferation statistically diminished markedly following p27(kip1) overexpression in the endometriosis group. This process was accompanied, however, by a statistically significant modulation of the cell cycle-related proteins p16, p21, p27 and p53 markedly increase following p27(kip1) overexpression in the endometriosis group (p < 0.001) and an increase in apoptotic cells was observed. In the endometriosis group, significant downregulation of VEGF expression was observed 7 days after p27(kip1) overexpression, attaining levels strikingly similar to those observed in the control endometrial cells. The findings of this study showed a link between the cell cycle control protein (p27(kip1)) and angiogenesis (VEGF). Our results, also reinforces the background of endometrial dysfunction as part of the origin of endometriosis. We believe that better knowledge of endometrium milieu and the establishment of the link between different, previously describe, altered pathways in this tissue can facilitate future genetic cell therapy.

Polymers in gene therapy technology

There are several barriers to gene delivery. One of the biggest challenges is the design of appropriate vectors. Currently, nonviral vectors have received significant attention because of low toxicity, potential for tissue specificity, stability during storage, lack of immunogenicity, and relatively low production cost. Despite the high efficiency of viral vectors, they show limited clinical applications because of potentially fatal adverse effects and because of the likelihood of the immune response shutting down the transgene expression system. Nonviral technologies comprise plasmid‐based expression systems harboring a gene that encodes a therapeutic protein along with a synthetic gene delivery system. This review provides a broad perspective on recent improvements in the development of four kinds of nonviral vectors that are based on polymers, peptides, lipids, and DNA and discusses the cytotoxicity associated with gene therapy. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Multifunctional polyamidoamine-modified selenium nanoparticles dual-delivering siRNA and cisplatin to A549/DDP cells for reversal multidrug resistance

Multidrug resistance (MDR) is a major barrier against effective cancer treatment. Dual-delivering a therapeutic small interfering RNA (siRNA) and chemotherapeutic agents has been developed to reverse drug resistance in tumor cells. In this study, amine-terminated generation 5 polyamidoamine (PAMAM) dendrimers (G5.NH2)-modified selenium nanoparticles (G5@Se NP) were synthesized for the systemic dual-delivery of mdr1 siRNA and cisplatin (cis-diamminedichloroplatinum-(II), DDP), which was demonstrated to enhance siRNA loading, releasing efficiency and gene-silencing efficacy. When the mdr1 siRNA was conjugated with G5@Se NP via electrostatic interaction, a significant down-regulation of P-glycoprotein and multidrug resistance-associated protein expression was observed; G5@Se-DDP-siRNA arrested A549/DDP cells at G1 phase and led to enhanced cytotoxicity in A549/DDP cells through induction of apoptosis involving the AKT and ERK signaling pathways. Interestingly, G5@Se-DDP NP were much less reactive than DDP in the reactions with both MT and GSH, indicating that loading of DDP in a nano-delivery system could effectively prevent cell detoxification. Furthermore, animal studies demonstrated that the new delivery system of G5@Se-DDP-siRNA significantly enhanced the anti-tumor effect on tumor-bearing nude mice, with no appreciable abnormality in the major organs. These results suggest that G5@Se NP could be a potential platform to combine chemotherapy and gene therapy technology in the treatment of human disease.

Molecular Genetic Markers as a Basis for Personalized Medicine / MOLEKULARNO-GENETIČKI MARKERI KAO OSNOV ZA PERSONALIZOVANU MEDICINU

Summary Nowadays, genetics and genomics are fully integrated into medical practice. Personalized medicine, also called genome-based medicine, uses the knowledge of the genetic basis of disease to individualize treatment for each patient. A number of genetic variants, molecular genetic markers, are already in use in medical practice for the diagnosis, prognosis and follow-up of diseases (monogenic hereditary disorders, fusion genes and rearrangements in pediatric and adult leukemia) and presymptomatic risk assessment (BRCA 1/2 for breast cancer). Additionally, the application of pharmacogenomics in clinical practice has significantly contributed to the individualization of therapy in accordance with the patient’s genotype and gene expression profile. Genetic testing for several pharmacogenomic markers (TPMT, UGT1A1, CYP2C9, VKORC1) is mandatory or recommended prior to the initiation of therapy. The most important achievement of genome-based medicine is molecular-targeted therapy, tailored to the genetic profile of a disease. Testing for gene variants in cancer (BCR-ABL, PML/RARa, RAS, BCL-2) is part of the recommended evaluation for different cancers, in order to achieve better management of the disease. The ultimate goal of medical science is to develop gene therapy which will fight or prevent a disease by targeting the disease causing genetic defect. Gene therapy technology is rapidly developing, and has already been used with success. Although medicine has always been essentially »personal« to each patient, personalized medicine today uses modern technology and knowledge in the field of molecular genetics and genomics, enabling a level of personalization which leads to significant improvement in health care.

ИнфузИонная поддержка гентерапевтИческИх технологИй в леченИИ больных с сИндромом дИабетИческой стопы

ИнфузИонная поддержка гентерапевтИческИх технологИй в леченИИ больных с сИндромом дИабетИческой стопы

Verification and Optimal Control of Context-Sensitive Probabilistic Boolean Networks Using Model Checking and Polynomial Optimization

One of the significant topics in systems biology is to develop control theory of gene regulatory networks (GRNs). In typical control of GRNs, expression of some genes is inhibited (activated) by manipulating external stimuli and expression of other genes. It is expected to apply control theory of GRNs to gene therapy technologies in the future. In this paper, a control method using a Boolean network (BN) is studied. A BN is widely used as a model of GRNs, and gene expression is expressed by a binary value (ON or OFF). In particular, a context-sensitive probabilistic Boolean network (CS-PBN), which is one of the extended models of BNs, is used. For CS-PBNs, the verification problem and the optimal control problem are considered. For the verification problem, a solution method using the probabilistic model checker PRISM is proposed. For the optimal control problem, a solution method using polynomial optimization is proposed. Finally, a numerical example on the WNT5A network, which is related to melanoma, is presented. The proposed methods provide us useful tools in control theory of GRNs.

Why commercialization of gene therapy stalled; examining the life cycles of gene therapy technologies

This report examines the commercialization of gene therapy in the context of innovation theories that posit a relationship between the maturation of a technology through its life cycle and prospects for successful product development. We show that the field of gene therapy has matured steadily since the 1980s, with the congruent accumulation of >35 000 papers, >16 000 US patents, >1800 clinical trials and >$4.3 billion in capital investment in gene therapy companies. Gene therapy technologies comprise a series of dissimilar approaches for gene delivery, each of which has introduced a distinct product architecture. Using bibliometric methods, we quantify the maturation of each technology through a characteristic life cycle S-curve, from a Nascent stage, through a Growing stage of exponential advance, toward an Established stage and projected limit. Capital investment in gene therapy is shown to have occurred predominantly in Nascent stage technologies and to be negatively correlated with maturity. Gene therapy technologies are now achieving the level of maturity that innovation research and biotechnology experience suggest may be requisite for efficient product development. Asynchrony between the maturation of gene therapy technologies and capital investment in development-focused business models may have stalled the commercialization of gene therapy.

Advances in gene therapy technologies to treat retinitis pigmentosa

Retinitis pigmentosa (RP) is a class of diseases that leads to progressive degeneration of the retina. Experimental approaches to gene therapy for the treatment of inherited retinal dystrophies have advanced in recent years, inclusive of the safe delivery of genes to the human retina. This review is focused on the development of gene therapy for RP using recombinant adenoassociated viral vectors, which show a positive safety record and have so far been successful in several clinical trials for congenital retinal disease. Gene therapy for RP is under development in a variety of animal models, and the results raise expectations of future clinical application. Nonetheless, the translation of such strategies to the bedside requires further understanding of the mutations and mechanisms that cause visual defects, as well as thorough examination of potential adverse effects.

Biodegradable nanoparticles for gene therapy technology

Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

Ultrasound-Mediated Vascular Endothelial Growth Factor C (VEGF-C) Gene Microbubble Transfection Inhibits Growth of MCF-7 Breast Cancer Cells

We evaluated the effects of ultrasound-mediated microbubble transfection of VEGF-C siRNA on breast cancer cells in vitro and in vivo. MCF-7 cells were transfected with VEGF-C siRNA and the protein and mRNA expression of VEGF-C was tested using Western blot and qRT-PCR. Twenty nude mice tumors were established by injecting with MCF-7 cells, and were randomized into four groups when palpable tumors reached 190 mm3. The length and width of MCF-7 tumors in mice were measured every 3 days. After 20 days, all mice were killed and the expression of VEGF-C in tumor tissue was also detected by Western blot and qRT-PCR. Results showed that VEGF-C siRNA effectively suppressed the protein and mRNA expression of VEGF-C in MCF-7 cells in vitro. VEGF-C siRNA inhibited the growth of human lymphatic endothelial cells (LECs) and MCF-7 cells. The volume and weight of MCF-7 tumor in VEGF-C siRNA microbubble with irradiation group were reduced with more extent than that in other groups in vivo. The present study highlights that VEGF-C siRNA in combination with ultrasound-mediated microbubble destruction (UMMD) could be a powerful, promising nonviral technology for breast cancer gene therapy.

Targeting Tumors Using Nanoparticle Platforms: A Phase I Study of a Systemically Administered Gene Therapy System

The potential for nonviral gene therapy to treat cancer has been limited by the difficulty of targeting therapeutic genes to tumors. In this issue of Molecular Therapy, Senzer et al.1 show evidence of specific tumor targeting as well as clinical efficacy in a phase I trial of a nonviral vector. This is the first phase I clinical trial to demonstrate tumor specificity and uptake by metastatic tumors of a systemically delivered liposomal nanoparticle. Importantly, the therapeutic nanoparticle elicited minimal side effects and the majority of patients demonstrated stable disease. This phase I trial has shown this delivery system to be a safe, stable, efficient, and tumor-specific drug delivery platform for systemic administration.

Novel siRNA delivery strategy: a new "strand" in CNS translational medicine?

RNA interference has been envisaged as a powerful tool for molecular and clinical investigation with a great potential for clinical applications. In recent years, increased understanding of cancer biology and stem cell biology has dramatically accelerated the development of technology for cell and gene therapy in these areas. This paper is a review of the most recent report of innovative use of siRNA to benefit several central nervous system diseases. Furthermore, a description is made of innovative strategies of delivery into the brain by means of viral and non-viral vectors with high potential for translation into clinical use. Problems are also highlighted that might hamper the transition from bench to bed, analyzing the lack of reliable preclinical models with predictive validity and the lack of effective delivery systems, which are able to overcome biological barriers and specifically reach the brain site of action.

Optimal Control of Gene Regulatory Networks with Effectiveness of Multiple Drugs: A Boolean Network Approach

Developing control theory of gene regulatory networks is one of the significant topics in the field of systems biology, and it is expected to apply the obtained results to gene therapy technologies in the future. In this paper, a control method using a Boolean network (BN) is studied. A BN is widely used as a model of gene regulatory networks, and gene expression is expressed by a binary value (0 or 1). In the control problem, we assume that the concentration level of a part of genes is arbitrarily determined as the control input. However, there are cases that no gene satisfying this assumption exists, and it is important to consider structural control via external stimuli. Furthermore, these controls are realized by multiple drugs, and it is also important to consider multiple effects such as duration of effect and side effects. In this paper, we propose a BN model with two types of the control inputs and an optimal control method with duration of drug effectiveness. First, a BN model and duration of drug effectiveness are discussed. Next, the optimal control problem is formulated and is reduced to an integer linear programming problem. Finally, numerical simulations are shown.

MITO-Porter; A Cutting-edge Technology for Mitochondrial Gene Therapy

Gene therapy is an attractive strategy, for not only targeting nuclear genome, but the mitochondrial genome as well. Human mitochondrial DNA (mtDNA) encodes 13 subunits of the electron transport chain, 22 tRNAs, and 2 rRNAs and their mutations cause a wide range of mitochondrial diseases. Each cell contains hundreds to thousands of mtDNAs, and in the case of a diseased cell, the mitochondrion possesses both mutant mtDNA and wild-type mtDNA. It is generally accepted that the disease phenotype appears when the proportion of the pathogenic mutant mtDNA exceeds a certain threshold. Therefore, the suppression of mutant mtDNA or supplementing wild-type mtDNA will control the onset of mitochondrial disease. To achieve the transfection of an exogenous therapeutic gene to the mitochondrial matrix where mtDNA is transcribed and translated, it is necessary to transfer cargos through mitochondrial outer and inner membranes. Several methods have been examined for mitochondrial transfection, but a universal, wide-ranging transfection technique has yet not been established. We recently developed a mitochondrial targeting delivery system, namely the MITO-Porter. The MITO-Porter is liposomal nanocarrier with a mitochondrial fusogenic lipid composition. We reported that the MITO-Porter could deliver chemical compounds and proteins to the mitochondrial matrix via membrane fusion. In this review, we report (1) on the pharmacological enhancement of lecithinized superoxide dismutase (PC-SOD) using MITO-Porter, (2) the transcription activation of exogenous DNA by mitochondrial transcription factor A (TFAM), and (3) perspectives on a mitochondrial targeting device.

Baxter Pursues Haemophilia B Gene Therapy with Chatham Therapeutics Collaboration

Baxter International has entered into an exclusive global development and commercialisation agreement with Chatham Therapeutics, an affiliate of Asklepios BioPharmaceutical, for potential treatments for haemophilia B using Chatham’s Biological Nano Particles™ gene therapy technology. Baxter has paid US$25 M upfront to advance Chatham’s haemophilia B programme through early clinical trials and has global marketing and commercialisation rights to resulting therapies.