• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6155-6157
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• 2012

Background: Mutations in the MAPK (Mitogen Activated Protein Kinase) signaling pathway - EGFR/Ras/RAF/MEK have been associated with the development of several carcinomas. ERK2, a downstream target of the MAPK pathway and a founding member of the MAPK family is activated by cellular signals emanating at the cell membrane. Activated ERK2 translocates into the nucleus to transactivate genes that promote cell proliferation. MKP - a dual specific phosphatase - interacts with activated ERK2 via the common docking (CD) domain of the later to inactivate (dephosphorylate) and effectively terminate further cell proliferation. A constitutively active form of ERK2 carrying a single point mutation - E322K in its CD domain, was earlier reported by our laboratory. In the present study, we investigated the prevalence of this CD domain E322K mutation in 88 well differentiated OSCC tissue samples. Materials and Method: Genomic DNA specimens isolated from 88 oral squamous cell carcinoma tissue samples were amplified with primers flanking the CD domain of the ERK2 gene. Subsequently, PCR amplicons were gel purified and subjected to direct sequencing to screen for mutations. Results: Direct sequencing of eighty eight OSCC samples identified an E322K CD domain mutation in only one (1.1%) OSCC sample. Conclusions: Our result indicates that mutation in the CD domain of ERK2 is rare in OSCC patients, which suggests the role of genetic alterations in other mitogenic genes in the development of carcinoma in the rest of the patients. Nevertheless, the finding is clinically significant, as the relatively rare prevalence of the E322K mutation in OSCC suggests that ERK2, being a common end point signal in the multi-hierarchical mitogen activated signaling pathway may be explored as a viable drug target in the treatment of OSCC.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.2
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• pp.157-173
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• 2003

The history of pediatric psychopharmacology is very short and the research on safety, efficacy and side effects is preliminary and long-term effect on growth and maturation is not well known yet. Clinical findings have shown that the responses to antidepressants, antipsychotics, CNS stimulants and steroids in children and adolescents might be different from adult populations. Based on these findings, this paper reviewed three issues, Firstly, in developmental pharmacokinetics. the author discussed the developmental factors affecting drug absorption, distribution, protein-binding, metabolism and excretion. Secondly, in developmental pharmacodynamics, developmental characteristics of dopamine, serotonin, norepinephrine receptors and their clinical implications were reviewed. Lastly, in pharamcogenetic part, the clinical utility of pharmacogenetics, pharmacokinetic aspects of pharmacogenetics, the pharmacodynamic aspects of pharmacogenetics, the association studies of dopamine-related alleles in neuropsychiatric disorders such as attention-deficit hyperactivity disorders or Tourette’s disorders, pharmacogenetic studies dopamine-related alleles and the pharmacogenetic studies of serotonin-related alleles. Based on these preliminary research, future pharmacogenetic applications in childhood and adolescent psychiatry were also discussed.

• Journal of Ginseng Research
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• v.28 no.2
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• pp.87-93
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• 2004

The effect of ginsenoside-Rb2, one of a major pharmacological component of Panax ginseng C.A. Meyer, on low density lipoprotein (LDL) receptor expression was investigated and compared with hypocholesterolemic drug lovastatin. In HepG2 cell, exogenous cholesterol decreased LDL receptor mRNA expression, but ginsenoside-Rb2 recovered this reduction of LDL receptor mRNA up to normal expression level. Lovastatin also increased LDL receptor mRNA expression as similar as ginsenoside-Rb2 did. The reduction of sterol regulatory element binding protein (SREBP) transcription by exogenous cholesterol was also similarly recovered by ginsenoside-Rb2 and lovastatin addition. Compound K, a metabolite of ginsenoside-Rb2 and -Rb1 by human intestinal bacteria also increased the SREBP mRNA expression in cholesterol-enriched condition. Ginsenoside-Rb2 seems to up-regulate LDL receptor mRNA expression through the induction of de novo SREBP transcription. Therefore, increased expression of SREBP mRNA by ginsenoside-Rb2 elevated the LDL receptor mRNA expression in HepG2 cells, and these inductions possibly drop the plasma cholesterol level in hypercholesterolemia patients, in vivo, as likely in case of lovastatin.

• Journal of Ginseng Research
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• v.35 no.4
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• pp.471-478
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• 2011

Ginseng, the root of Panax ginseng, is one of the oldest herbal medicines. It has a variety of physiological and pharmacological effects. Recently, we isolated a subset of glycolipoproteins that we designated gintonin, and demonstrated that it induced transient change in intracellular calcium concentration $([Ca^{2+}]_i)$ in cells via G-protein-coupled receptor signaling pathway(s). The previous method for gintonin isolation included multiple steps using methanol, butanol, and other organic solvents. In the present study, we developed a much simple method for the preparation of gintonin from ginseng root using 80% ethanol extraction. The extracted fraction was designated edible gintonin. This method produced a high yield of gintonin (0.20%). The chemical characteristics of gintonin such as molecular weight and the composition of the extract product were almost identical as the gintonin prepared using the previous extraction regimen involving various organic solvents. We also examined the physiological effects of edible gintonin on endogenous $Ca^{2+}$-activated $Cl^-$ channel activity of Xenopus oocytes. The 50% effective dose was $1.03{\pm}0.3\;{\mu}g$/mL. Finally, since gintonin preparation through ethanol extraction is easily reproducible, gintonin could be commercially applied for ginseng-derived functional health food and/or drug following the confirmations of in vitro and in vivo physiological and pharmacological effects of gintonin.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.869-873
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• 2012

Balance between bone-forming osteoblasts and bone-resorbing osteoclasts is important in bone homeostasis. Unusual balance between bone-forming osteoblasts and bone-resorbing osteoclasts leads to bone diseases, such as osteoporosis. Saururus chinensis has been widely used in oriental medicine. Saururus chinensis has been known that has antioxidant and anticancer effect. But, the effect of Saururus chinensis in osteoclast differentation remains unknown. We examined the effect of Saururus chinensis in receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. From the results of our study, we found that saururus chinensis clearly inhibited RANKL-induced osteoclast differentiation in bone marrow macrophages (BMM) in a dose dependent manner without toxicity. Saururus chinensis inhibited the phosphorylation of JNK, P38, AKT, and ERK induced by RANKL. The mRNA expression of NFATc1, TRAP, and OSCAR induced by RANKL was inhibited by Saururus chinensis treatment. Moreover Saururus chinensis suppressed the protein expression of c-Fos and NFATc1 in BMMs treated with RANKL. These results suggest that Saururus chinensis may be a useful drug in the treatment of bone-related disease.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.5
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• pp.687-692
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• 2012

Schizandra chinensis extract has been known to possess a variety of efficacy including antitumor. However, it remains unclear how schizandrin, which is a major biological active ingredient of Schizandra chinensis, exerts antitumor effect. This study was designed to investigate the mechanism by which schizandrin inhibits tumor growth and metastasis. In in vivo test using tumor model mice injected with B16BL6 cell line, mice treated with 10 and 100 ${\mu}g/ml$ schizandrin showed a significant inhibition by $73.79{\pm}6.43%$ and $90.46{\pm}1.72%$, respectively, compared with positive tumor controls. Schizandrin did not exert a significant toxicity for the normal cells (HUVECs) and tumor cell lines (A549, B16BL6, Du145, Huh7). Treatment with schizandrin at 10 and 100 ${\mu}g$/head significantly inhibited the tumor-induced angiogenesis by $68.04{\pm}32.21%$ and $103.8{\pm}34.99%$ compared with the positive control group, respectively. Using in vivo lung metastasis model, tumor metastasis assay revealed that 10 and 100 ${\mu}g$/head schizandrin significantly decreased the metastatic lung tumor by $37.51{\pm}8.15%$ and $75.53{\pm}4.38%$ compared with positive controls, respectively. On the other hand, schizandrin did not affect the adherence of B16BL6 cell line to extracellular matrix protein. These results demonstrate that schizandrin exerts inhibitory effect on tumor growth and metastasis by inhibiting angiogenesis. This study thus suggest that schizandrin may be a candidate molecule target for cancer drug development.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.21-27
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• 2014

Objective : Infectious spinal disease is regarded as an infection by a specific organism that affects the vertebral body, intervertebral disc and adjacent perivertebral soft tissue. Its incidence seems to be increasing as a result of larger proportion of the older patients with chronic debilitating disease, the rise of intravenous drug abuser, and the increase in spinal procedure and surgery. In Korea, studies assessing infectious spinal disease are rare and have not been addressed in recent times. The objectives of this study are to describe the epidemiology of all kind of spinal infectious disease and their clinical and microbiological characteristics as well as to assess the diagnostic methodology and the parameters related to the outcomes. Methods : A retrospective study was performed in all infectious spinal disease cases presenting from January 2005 to April 2010 to three tertiary teaching hospitals within a city of 1.5 million in Korea. Patient demographics, risk factors, clinical features, and outcomes were assessed. Risk factors entailed the presence of diabetes, chronic renal failure, liver cirrhosis, immunosuppressants, remote infection, underlying malignancy and previous spinal surgery or procedure. We comparatively analyzed the results between the groups of pyogenic and tuberculous spinal infection. SPSS version 14 statistical software was used to perform the analyses of the data. The threshold for statistical significance was established at p<0.05. Results : Ninety-two cases fulfilled the inclusion criteria and were reviewed. Overall, patients of tuberculous spinal infection (TSI) and pyogenic spinal infection (PSI) entailed 20 (21.7%) and 72 (78.3%) cases, respectively. A previous spinal surgery or procedure was the most commonly noted risk factor (39.1%), followed by diabetes (15.2%). The occurrence of both pyogenic and tuberculous spondylitis was predominant in the lumbar spine. Discs are more easily invaded in PSI. At initial presentation, white cell blood count and C-reactive protein levels were higher in PSI compared to TSI (p<0.05). Etiological agents were identified in 53.3%, and the most effective method for identification of etiological agents was tissue culture (50.0%). Staphyococcus aureus was the most commonly isolated infective agent associated with pyogenic spondylitis, followed by E. coli. Surgical treatment was performed in 31.5% of pyogenic spondylitis and in 35.0% of tuberculous spondylitis cases. Conclusion : Many previous studies in Korea usually reported that tuberculous spondylitis is the predominant infection. However, in our study, the number of pyogenic infection was 3 times greater than that of tuberculous spinal disease. Etiological agents were identified in a half of all infectious spinal disease. For better outcomes, we should try to identify the causative microorganism before antibiotic therapy and make every effort to improve the result of culture and biopsy.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.162-172
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• 2002

Schizosaccharomyces pombe is suited for the study of cytokinesis as it divides by forming a septum in the middle of the cell at the end of mitosis. To enhance our understanding of the cytokinesis, we have carried out a genetic screen for temperature-sensitive S. pombe mutants that show defects in septum formation and cell division. Here we present the isolation and characterization of a new temperature-sensitive mutant, sun1(septum uncontrolled), which undergoes uncontrolled septation during cell division cycle at restrictive temperature $(37^{\circ}C)$. In sun1 mutant, actin ring and septum are positioned at random locations and angles, and nuclear division cycle continues. These observations suggest that the sun] gene product is required for the proper placement of the actin ring as well as precise septation. The sun] mutant is monogenic recessive mutation unlinked to previously known various cdc genes of S. pombe. In a screen for $sunl^+$ gene to complement the sun] mutant, we have cloned a gene, $susl^+$(suppressor of sun1 mutant), that encodes a protein of 689 amino acids. The predicted amino acid sequence of $susl^+$ gene is similar to the human hMadlp and Saccharomyces cerevisiae Mad1p, a component of the spindle checkpoint in eukaryotic cells. The null mutant of $susl^+$ gene grows normally at various temperatures and has the increased sensitivity to anti-microtubule drug, while $susl^+$ mutant shows no sensitivity to microtubule destabilizing drugs. The putative S. pombe Sus1p directly interacts with S. pombe Mad2p in yeast two-hybrid assays. These data suggest that the newly isolated susr gene encodes S. pombe Mad1p and suppresses sun] mutant defective in controlled septation in a cell division cycle.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.120-122
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• 2007

All living organisms use numerous signal-transduction pathways to sense and respond to their environments and thereby survive and proliferate in a range of biological niches. Molecular dissection of these signalling networks has increased our understanding of these communication processes and provides a platform for therapeutic intervention when these pathways malfunction in disease states, including infection. Owing to the expanding availability of sequenced genomes, a wealth of genetic and molecular tools and the conservation of signalling networks, members of the fungal kingdom serve as excellent model systems for more complex, multicellular organisms. Here, we employed Cryptococcus neoformans as a model system to understand how fungal-signalling circuits operate at the molecular level to sense and respond to a plethora of environmental stresses, including osmoticshock, UV, high temperature, oxidative stress and toxic drugs/metabolites. The stress-activated p38/Hog1 MAPK pathway is structurally conserved in many organisms as diverse as yeast and mammals, but its regulation is uniquely specialized in a majority of clinical Cryptococcus neoformans serotype A and D strains to control differentiation and virulence factor regulation. C. neoformans Hog1 MAPK is controlled by Pbs2 MAPK kinase (MAPKK). The Pbs2-Hog1 MAPK cascade is controlled by the fungal "two-component" system that is composed of a response regulator, Ssk1, and multiple sensor kinases, including two-component.like (Tco) 1 and Tco2. Tco1 and Tco2 play shared and distinct roles in stress responses and drug sensitivity through the Hog1 MAPK system. Furthermore, each sensor kinase mediates unique cellular functions for virulence and morphological differentiation. We also identified and characterized the Ssk2 MAPKKK upstream of the MAPKK Pbs2 and the MAPK Hog1 in C. neoformans. The SSK2 gene was identified as a potential component responsible for differential Hog1 regulation between the serotype D sibling f1 strains B3501 and B3502 through comparative analysis of their meiotic map with the meiotic segregation of Hog1-dependent sensitivity to the fungicide fludioxonil. Ssk2 is the only polymorphic component in the Hog1 MAPK module, including two coding sequence changes between the SSK2 alleles in B3501 and B3502 strains. To further support this finding, the SSK2 allele exchange completely swapped Hog1-related phenotypes between B3501 and B3502 strains. In the serotype A strain H99, disruption of the SSK2 gene dramatically enhanced capsule biosynthesis and mating efficiency, similar to pbs2 and hog1 mutations. Furthermore, ssk2, pbs2, and hog1 mutants are all hypersensitive to a variety of stresses and completely resistant to fludioxonil. Taken together, these findings indicate that Ssk2 is the critical interface protein connecting the two-component system and the Pbs2-Hog1 pathway in C. neoformans.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.204-210
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• 2006

Ethyl (S)-4-chloro-3-hydroxybutyrate is a useful intermediate for the synthesis of Atorvastatin, a chiral drug to hypercholesterolemia. In this research, two 4-chloro-3-hydroxybutyro-nitrile-degrading strains were isolated from soil sample. They were identified as Rhodococcus erythropolis strains by 16S rRNA analysis. The nitrile-degrading enzyme(s) were suggested to be nitrile hydratase and amidase rather than nitrilase from the result of thin layer chromatography analysis. The corresponding genes were obtained by PCR cloning method. The predicted protein sequences had identities more than 96% with nitrile hydratase ${\alpha}-subunit$, nitrile hydratase ${\beta}-subunit$, and amidase of R. erythropolis. The 4-chloro-3-hydroxybutyronitrile-hydrolyzing activities in both strains were increased dramatically by ${\varepsilon}-caprolactam$ which was known as good inducer for nitrile hydratase. Both intact cells and cell-free extract could hydrolyze the nitrile compound. So, the intact cell and the enzymes could be used as potential biocatalyst for the production of 4-chloro-3-hydroxybutyric acid.