Attenuated and Protease-Profile Modified Sendai Virus Vectors as a New Tool for Virotherapy of Solid Tumors

Peer reviewe

Evaluation of short‐term safety of ultrasound‐guided foetal fluid sampling in the dog (Canis lupus familiaris)

Background: In humans, analysis of amniotic fluid is widely used for diagnostic and prognostic purposes. Amniocentesis has scarcely been used in veterinary medicine to date, despite a tremendous potential for clinical and research applications in dogs. Our study aimed to establish a safe method for foetal fluid sampling in female dogs. Methods: Two transabdominal ultrasound-guided methods were assessed: the "free hand" and the needle-guided bracket sampling. In addition, through a subsequent routinely scheduled ovariohysterectomy, fluid was directly collected. Samples from 98 conceptuses were collected at day 46.7 +/- 7.5 of pregnancy. Results: The amount of fluid retrieved varied between 0.5 and 5.0 ml per collection. Macroscopic examination of the uterus and conceptuses identified 53% of the puncture sites. Neither fluid leakage nor foetal injury was detected, and six hematomas (5.8%) were visible. Ultrasound-guided foetal fluid collection was found to be potentially safe, and it can be performed by using either transabdominal method. Conclusion: Foetal fluid collection is possible with relative ease and low short-term risk, and may open paths for diagnostic, therapeutic and research purposes in dogs. The procedure can provide new insights into prenatal clinical medicine, including diagnostics of foetal deaths, early identification of heritable diseases and so on

Long-term microdystrophin gene therapy is effective in a canine model of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an incurable X-linked muscle-wasting disease caused by mutations in the dystrophin gene. Gene therapy using highly functional microdystrophin genes and recombinant adeno-associated virus (rAAV) vectors is an attractive strategy to treat DMD. Here we show that locoregional and systemic delivery of a rAAV2/8 vector expressing a canine microdystrophin (cMD1) is effective in restoring dystrophin expression and stabilizing clinical symptoms in studies performed on a total of 12 treated golden retriever muscular dystrophy (GRMD) dogs. Locoregional delivery induces high levels of microdystrophin expression in limb musculature and significant amelioration of histological and functional parameters. Systemic intravenous administration without immunosuppression results in significant and sustained levels of microdystrophin in skeletal muscles and reduces dystrophic symptoms for over 2 years. No toxicity or adverse immune consequences of vector administration are observed. These studies indicate safety and efficacy of systemic rAAV-cMD1 delivery in a large animal model of DMD, and pave the way towards clinical trials of rAAV-microdystrophin gene therapy in DMD patients

Advances in gene therapy for muscular dystrophies

Duchenne muscular dystrophy (DMD) is a recessive lethal inherited muscular dystrophy caused by mutations in the gene encoding dystrophin, a protein required for muscle fibre integrity. So far, many approaches have been tested from the traditional gene addition to newer advanced approaches based on manipulation of the cellular machinery either at the gene transcription, mRNA processing or translation levels. Unfortunately, despite all these efforts, no efficient treatments for DMD are currently available. In this review, we highlight the most advanced therapeutic strategies under investigation as potential DMD treatments

Membrane-type 5 matrix metalloproteinase is expressed in differentiated neurons and regulates axonal growth.

Expression of membrane-type (MT) 5 matrix metalloproteinase (MMP) in the mouse brain was examined. MT5-MMP was expressed in the cerebrum in embryos, but it declined after birth. In contrast, expression in the cerebellum started to increase postnatally and continued thereafter. The cells expressing MT5-MMP were postmitotic neurons that showed gelatinolytic activities. Specific expression of MT5-MMP was observed in the neurons but not in the glial cells when embryonal mouse carcinoma P19 cells were differentiated in vitro by retinoic acid treatment. Neurons isolated from dorsal root ganglia also expressed MT5-MMP, and it was localized at the edge of growth cone. Proteoglycans inhibit neurite extension and regulate synaptogenesis. The inhibitory effect of the proteoglycans on neurite extension of dorsal root ganglia neurons was effectively eliminated by recombinant MT5-MMP. Thus, MT5-MMP expressed in neurons may play a role in axonal growth that contributes to the regulation of neural network formation

Membrane type 4 matrix metalloproteinase (MT4-MMP, MMP-17) is a glycosylphosphatidylinositol-anchored proteinase.

Among the five membrane-type matrix metalloproteinases (MT-MMPs), MT1-, MT2-, MT3-, and MT5-MMPs have about a 20-amino acid cytoplasmic tail following the transmembrane domain. In contrast, a putative transmembrane domain of MT4-MMP locates at the very C-terminal end, and the expected cytoplasmic tail is very short or nonexistent. Such sequences often act as a glycosylphosphatidylinositol (GPI) anchoring signal rather than as a transmembrane domain. We thus examined the possibility that MT4-MMP is a GPI-anchored proteinase. Our results showed that [(3)H]ethanolamine, which can be incorporated into the GPI unit, specifically labeled the MT4-MMP C-terminal end in a sequence-dependent manner. In addition, phosphatidylinositol-specific phospholipase C treatment released the MT4-MMP from the surface of transfected cells. These results indicate that MT4-MMP is the first GPI-anchored proteinase in the MMP family. During cultivation of the transfected cells, MT4-MMP appeared to be shed from the cell surface by the action of an endogenous metalloproteinase. GPI anchoring of MT4-MMP on the cell surface indicates a unique biological function and character for this proteinase

Membrane-type 1 matrix metalloproteinase cleaves CD44 and promotes cell migration.

Migratory cells including invasive tumor cells frequently express CD44, a major receptor for hyaluronan and membrane-type 1 matrix metalloproteinase (MT1-MMP) that degrades extracellular matrix at the pericellular region. In this study, we demonstrate that MT1-MMP acts as a processing enzyme for CD44H, releasing it into the medium as a soluble 70-kD fragment. Furthermore, this processing event stimulates cell motility; however, expression of either CD44H or MT1-MMP alone did not stimulate cell motility. Coexpression of MT1-MMP and mutant CD44H lacking the MT1-MMP-processing site did not result in shedding and did not promote cell migration, suggesting that the processing of CD44H by MT1-MMP is critical in the migratory stimulation. Moreover, expression of the mutant CD44H inhibited the cell migration promoted by CD44H and MT1-MMP in a dominant-negative manner. The pancreatic tumor cell line, MIA PaCa-2, was found to shed the 70-kD CD44H fragment in a MT1-MMP-dependent manner. Expression of the mutant CD44H in the cells as well as MMP inhibitor treatment effectively inhibited the migration, suggesting that MIA PaCa-2 cells indeed use the CD44H and MT1-MMP as migratory devices. These findings revealed a novel interaction of the two molecules that have each been implicated in tumor cell migration and invasion

Human membrane type-4 matrix metalloproteinase (MT4-MMP) is encoded by a novel major transcript: isolation of complementary DNA clones for human and mouse mt4-mmp transcripts.

Five distinct membrane-type matrix metalloproteinases (MT-MMP) have been reported by cDNA cloning. However, the mt4-mmp gene product (MMP-17) has not been identified yet in spite of the cDNA isolation [Puente et al. (1996), Cancer Res. 56, 944-949]. In this study, we re-examined the transcripts for human mt4-mmp by 5' RACE and identified two types of transcripts. The minor one corresponded to the cDNA reported by Puente et al. and failed to express protein, and the other is the major transcript that has an extended open reading frame and expressed 67 and 71 kDa translation products. Thus, functional mt4-mmp has been identified for the first time

Human membrane type-4 matrix metalloproteinase (MT4-MMP) is encoded by a novel major transcript: isolation of complementary DNA clones for human and mouse mt4-mmp transcripts.

Five distinct membrane-type matrix metalloproteinases (MT-MMP) have been reported by cDNA cloning. However, the mt4-mmp gene product (MMP-17) has not been identified yet in spite of the cDNA isolation [Puente et al. (1996), Cancer Res. 56, 944-949]. In this study, we re-examined the transcripts for human mt4-mmp by 5' RACE and identified two types of transcripts. The minor one corresponded to the cDNA reported by Puente et al. and failed to express protein, and the other is the major transcript that has an extended open reading frame and expressed 67 and 71 kDa translation products. Thus, functional mt4-mmp has been identified for the first time