• Genomics & Informatics
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• v.3 no.4
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• pp.172-174
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• 2005

Recent anti-cancer approaches have been based to target tumor-specifically associated and/or causative molecules such as RNAs or proteins. As this specifically targeted anti-cancer modulator, we have previously described a novel human cancer gene therapeutic agent that is Tetrahymena group I intron-based trans-splicing ribozyme which can reprogram and replace human telomerase reverse transcriptase (hTERT) RNA to selectively induce tumor-specific cytotoxicity in cancer cells expressing the target RNA. Moreover, the specific ribozyme has been shown to efficiently retard tumor tissues in xenograft mice which had been inoculated with hTERT-expressing human cancer cells. In this study, we assessed specificity of trans-splicing reaction in cells to evaluate the therapeutic feasibility of the specific ribozyme. In order to analyze the trans-spliced products by the specific ribozyme in hTERT-positive cells, RT, 5'-end RACE-PCR, and sequencing reactions of the spliced RNAs were employed. Then, whole analyzed products resulted from reactions only with the hTERT RNA. This study suggested that the developed ribozyme perform highly specific RNA replacement of the target RNA in cells, hence trans-splicing ribozyme will be one of specific agents for genetic approach to revert cancer.

• BMB Reports
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• v.42 no.8
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• pp.535-539
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• 2009

Voltage-gated $K^+$ (Kv) channels are widely expressed in the plasma membranes of numerous cells such as epithelial cells. Recently, it has been demonstrated that Kv channels are associated with the proliferation of several types of cancer cells. Specifically, Kv1.3 seems to be involved in cancer cell proliferation and apoptosis. In the present study, we examined the expression of Kv1.3 in immortalized and tumorigenic human mammary epithelial cells. We also evaluated the expression level of Kv1.3 in each stage of breast cancer using mRNA isolated from breast cancer patients. In addition, treatment with tetraethylammonium, a Kv channel blocker, suppressed tumorigenic human mammary epithelial cell proliferation. Therefore, Kv1.3 may serve as a novel molecular target for breast cancer therapy while its stage-specific expression pattern may provide a potential diagnostic marker for breast cancer development.

• Biomedical Science Letters
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• v.24 no.4
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• pp.435-438
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• 2018

Acanthamoeba culbertsoni is the causative agent of granulomatous amoebic encephalitis (GAE), a condition that predominantly occurs in immunocompromised individuals and which is typically fatal. A mannose-binding protein (MBP) among lectins was shown to have strong A. castellanii pathogenic potential when correlated with major virulence proteins. In this study, protective effects were analyzed using the monoclonal antibody to A. culbertsoni MBP by quantification and were also compared with other free-living amoebae. For the amoebial cytotoxicity to the target cell, amoeba trophozoites were incubated with Chinese hamster ovary (CHO) cells. For the protective effects of antibodies, amoebae were pre-incubated with them for 4 h and then added to the target cells. After 24 h, the supernatants were collected and examined for host cell cytotoxicity by measuring lactate dehydrogenase (LDH) release. The cytotoxicity of A. culbertsoni to the CHO cells showed about 87.4%. When the monoclonal antibody was pre-incubated with A. culbertsoni, the amoebial cytotoxicity was remarkably decreased as shown at LDH release (1.858 absorbance), which was represented with about 49.9%. Taken together, it suggested that the monoclonal antibody against MBP be important to inhibit the cytotoxicity of A. culbertsoni trophozoites to the target cell. The antibody will be applied into an in vivo functional analysis, which would help to develop therapeutics.

• 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.

• Genomics & Informatics
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• v.5 no.1
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• pp.6-9
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• 2007

An RNase P ribozyme library has been developed as a tool for functional genomics studies. Each clone of this library contains a random 18-mer and the sequence of M1 RNA, the catalytic subunit of RNase P. Repression of target gene expression is thus achieved by the complementary binding of mRNA to the random guide sequence and the successive target cleavage via M1 RNA. Cellular expression of the ribozyme expression was confirmed, and EGFP mRNA was used as a model to demonstrate that the RNase P ribozyme expression system can inhibit the target gene expression. The constructed RNase P ribozyme library has a complexity of $1.4\times10^7$. This novel library system should become a useful in functional genomics, to identify novel gene functions in mammalian cells.

• Journal of Yeungnam Medical Science
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• v.23 no.2
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• pp.143-151
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• 2006

In the past decade, the median duration of survival among patients with advanced colorectal cancer has increased from 12 months to about 18 months, primarily as a results of the introduction of irinotecan and oxaliplatin. Advances in the understanding of the molecular mechanisms underlying the development and progression of cancer have resulted in the discovery of new therapeutic interventions that target specific molecular abnormalities. Their specificity, and therefore their potential to bind preferentially and modify tumor-specific targets, sparing normal tissues and causing fewer side-effects compared to conventional cytotoxic agents, makes them an attractive therapeutic option. The future of this approach for the treatment of solid tumors is promising.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.281-288
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• 2016

Apoptosis has been regarded as a therapeutic target because apoptosis is typically disturbed in human cancer. Silymarin found in the seeds of the milk thistle (Silybum marianum) has been reported to exert anti-cancer properties through apoptosis. This study was performed to investigate the molecular target for silymarin-mediated apoptosis in human colorectal cancer cells. Silymarin reduced the cell viability and induced an apoptosis in human colorectal cancer cells. ATF3 overexpression increased PARP cleavage by silymarin. Increased ATF3 expression in both protein and mRNA was observed in silymarin-treated cells. In addition, silymarin increased the luciferase activity of ATF3 promoter. Inhibition of JNK and IκK-α blocked silymarin-mediated ATF3 expression. The results suggest that silymarin induces apoptosis through JNK and IκKα-dependent ATF3 expression in human colorectal cancer cells.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8671-8671
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• 2016

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.83.1-83
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• 2002

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.109.2-109.2
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• 2006