• BMB Reports
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• v.49 no.2
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• pp.71-72
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• 2016

Focal cortical dysplasia type II (FCDII) is a focal malformation of the developing cerebral cortex and the major cause of intractable epilepsy. However, since the molecular genetic etiology of FCD has remained enigmatic, the effective therapeutic target for this condition has remained poorly understood. Our recent study on FCD utilizing various deep sequencing platforms identified somatic mutations in MTOR (existing as low as 1% allelic frequency) only in the affected brain tissues. We observed that these mutations induced hyperactivation of the mTOR kinase. In addition, focal cortical expression of mutant MTOR using in utero electroporation in mice, recapitulated the neuropathological features of FCDII, such as migration defect, cytomegalic neuron and spontaneous seizures. Furthermore, seizures and dysmorphic neurons were rescued by the administration of mTOR inhibitor, rapamycin. This study provides the first evidence that brain somatic activating mutations in MTOR cause FCD, and suggests the potential drug target for intractable epilepsy in FCD patients.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.97-107
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• 2016

Although many diseases could be treated by the development of modern medicine, there are some incurable diseases including brain cancer, Alzheimer disease, etc. To study human brain cancer, various animal models were reported. Among these animal models, mouse models are valuable tools for understanding brain cancer characteristics. In spite of many mouse brain cancer models, it has been difficult to find a new target molecule for the treatment of brain cancer. One of the reasons is absence of large animal model which makes conducting preclinical trials. In this article, we review a recent study of molecular characteristics of human brain cancer, their genetic mutation and comparative analysis of the mouse brain cancer model. Finally, we suggest the need for development of large animal models using somatic cell nuclear transfer in translational research.

• Development and Reproduction
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• v.27 no.1
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• pp.1-7
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• 2023

Small-cell lung cancer (SCLC) continues to be the deadliest of all lung cancer types. Its high mortality is largely attributed to the unchangeable development of resistance to standard chemo/radiotherapies, which have remained invariable for the past 30 years, underlining the need for new therapeutic approaches. Recent studies of SCLC genome revealed a large number of somatic alterations and identified remarkable heterogeneity of the frequent mutations except for the loss of both RB and P53 tumor suppressor genes (TSGs). Identifying the somatic alterations scattered throughout the SCLC genome will help to define the underlying mechanism of the disease and pave the way for the discovery of therapeutic vulnerabilities associated with genomic alterations. The new technique made it possible to determine the underlying mechanism for the discovery of therapeutic targets. To these ends, the techniques have been focused on understanding the molecular determinants of SCLC.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.26.1-26.14
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• 2020

Pancreatic ductal adenocarcinoma is a lethal cancer type that is associated with multiple gene mutations in somatic cells. Genetically engineered mouse is hardly applicable for developing a pancreatic cancer model, and the xenograft model poses a limitation in the reflection of early stage pancreatic cancer. Thus, in vivo somatic cell gene engineering with clustered regularly interspaced short palindromic repeats is drawing increasing attention for generating an animal model of pancreatic cancer. In this study, we selected Kras, Trp53, Ink4a, Smad4, and Brca2 as target genes, and applied Campylobacter jejuni Cas9 (CjCas9) and Streptococcus pyogens Cas9 (SpCas9) for developing pancreatic cancer using adeno associated virus (AAV) transduction. After confirming multifocal and diffuse transduction of AAV2, we generated SpCas9 overexpression mice, which exhibited high double-strand DNA breakage (DSB) in target genes and pancreatic intraepithelial neoplasia (PanIN) lesions with two AAV transductions; however, wild-type (WT) mice with three AAV transductions did not develop PanIN. Furthermore, small-sized Cjcas9 was applied to WT mice with two AAV system, which, in addition, developed high extensive DSB and PanIN lesions. Histological changes and expression of cancer markers such as Ki67, cytokeratin, Mucin5a, alpha smooth muscle actin in duct and islet cells were observed. In addition, the study revealed several findings such as 1) multiple DSB potential of AAV-CjCas9, 2) peri-ductal lymphocyte infiltration, 3) multi-focal cancer marker expression, and 4) requirement of > 12 months for initiation of PanIN in AAV mediated targeting. In this study, we present a useful tool for in vivo cancer modeling that would be applicable for other disease models as well.

• Journal of Korean Neurosurgical Society
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• v.63 no.1
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• pp.26-33
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• 2020

Glioblastoma (GBM) is a disease without any definite cure. Numerous approaches have been tested in efforts to conquer this brain disease, but patients invariably experience recurrence or develop resistance to treatment. New surgical tools, carefully chosen samples, and experimental methods are enabling discoveries at single-cell resolution. The present article reviews the cell-of-origin of isocitrate dehydrogenase (IDH)-wildtype GBM, beginning with the historical background for focusing on cellular origin and introducing the cancer genesis patterned on firework. The authors also review mutations associated with the senescence process in cells of the subventricular zone (SVZ), and biological validation of somatic mutations in a mouse SVZ model. Understanding GBM would facilitate research on the origin of other cancers and may catalyze the development of new management approaches or treatments against IDH-wildtype GBM.

• IMMUNE NETWORK
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• v.21 no.5
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• pp.34.1-34.16
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• 2021

Sjögren's syndrome (SS) is an autoimmune disease characterized by dryness of the mouth and eyes. The glandular dysfunction in SS involves not only T cell-mediated destruction of the glands but also autoantibodies against the type 3 muscarinic acetylcholine receptor or aquaporin 5 (AQP5) that interfere with the secretion process. Studies on the breakage of tolerance and induction of autoantibodies to these autoantigens could benefit SS patients. To break tolerance, we utilized a PmE-L peptide derived from the AQP5-homologous aquaporin of Prevotella melaninogenica (PmAqp) that contained both a B cell "E" epitope and a T cell epitope. Repeated subcutaneous immunization of C57BL/6 mice with the PmE-L peptide efficiently induced the production of Abs against the "E" epitope of mouse/human AQP5 (AQP5E), and we aimed to characterize the antigen specificity, the sequences of AQP5E-specific B cell receptors, and salivary gland phenotypes of these mice. Sera containing anti-AQP5E IgG not only stained mouse Aqp5 expressed in the submandibular glands but also detected PmApq and PmE-L by immunoblotting, suggesting molecular mimicry. Characterization of the AQP5E-specific autoantibodies selected from the screening of phage display Ab libraries and mapping of the B cell receptor repertoires revealed that the AQP5E-specific B cells acquired the ability to bind to the Ag through cumulative somatic hypermutation. Importantly, animals with anti-AQP5E Abs had decreased salivary flow rates without immune cell infiltration into the salivary glands. This model will be useful for investigating the role of anti-AQP5 autoantibodies in glandular dysfunction in SS and testing new therapeutics targeting autoantibody production.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.148-156
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• 2019

The Transgenic livestock can be useful for the production of disease-resistant animals, pigs for xenotranplantation, animal bioreactor for therapeutic recombinant proteins and disease model animals. Previously, conventional methods without using artificial nuclease-dependent DNA cleavage system were used to produce such transgenic livestock, but their efficiency is known to be low. In the last decade, the development of artificial nucleases such as zinc-finger necleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regulatory interspaced short palindromic repeat (CRISPR)/Cas has led to more efficient production of knock-out and knock-in transgenic livestock. However, production of knock-in livestock is poor. In mouse, genetically modified mice are produced by coinjecting a pair of knock-in vector, which is a donor DNA, with a artificial nuclease in a pronuclear fertilized egg, but not in livestock. Gene targeting efficiency has been increased with the use of artificial nucleases, but the knock-in efficiency is still low in livestock. In many research now, somatic cell nuclear transfer (SCNT) methods used after selection of cell transfected with artificial nuclease for production of transgenic livestock. In particular, it is necessary to develop a system capable of producing transgenic livestock more efficiently by co-injection of artificial nuclease and knock-in vectors into fertilized eggs.