• Nutrition Research and Practice
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• v.3 no.4
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• pp.265-271
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• 2009

The role that antioxidants play in the process of carcinogenesis has recently gained considerable attention. $\alpha$-Lipoic acid, a naturally occurring disulfide molecule, is a powerful antioxidant that reportedly exerts beneficial effects in patients with advanced cancer by reducing the level of reactive oxygen species and increasing glutathione peroxidase activity. In this study, we examined changes in the protein and mRNA expression associated with cell proliferation and apoptosis in MDA-MB-231 breast cancer cultured in the presence of various concentrations (0, 250, 500, and 1000 ${\mu}mol/L$) of $\alpha$-lipoic acid. The results revealed that $\alpha$-lipoic acid inhibited the growth of breast cancer cells in a dose-independent manner (P < 0.05). Additionally, $ErbB_2$ and $ErbB_3$ protein and mRNA expressions were significantly decreased in a dose-dependent manner in response to $\alpha$-lipoic acid (P < 0.05). Furthermore, the protein expression of phosphorylated Akt (p-Akt) levels and total Akt, and the mRNA expression of Akt were decreased dose-dependently in cells that were treated with $\alpha$-lipoic acid (P < 0.05). Bcl-2 protein and mRNA expressions were also decreased in cells that were treated with $\alpha$-lipoic acid (P < 0.05). However, Bax protein and mRNA expressions were increased in cells treated with $\alpha$-lipoic acid (P < 0.05). Finally, caspase-3 activity was significantly increased in a dose-dependent manner in cells treated with $\alpha$-lipoic acid (P < 0.05). In conclusion, we demonstrated that $\alpha$-lipoic acid inhibits cell proliferation and induces apoptosis in MDA-MB-231 breast cancer cell lines.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.6
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• pp.421-433
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• 2002

In order to elucidate the pathogenesis of cleft lip and palate, first of all, it is necessary to understand the developmental mechanisms of growth factors and extracellular matrix proteins in the tissues of cleft lip and palate. We have performed immunohistochemical studies on human cleft lip and palate tissues to elucidate the pathogenetic implications of cleft lip and palate. 16 specimens from postnatal human cleft lip and palate subjects and 17 specimens from autopsy of prenatal human cleft lip and palate were fixed in 10% buffered formalin, embedded in paraffin. The sections were routinely stained by hematoxylin and eosin, also stained by PAS, and followed by immunohistochemical stainings using the antiseras of growth factors and extracellular matrix proteins such as PCNA, S-100, c-erb-B2, MMP-3, MMP-10, HSP-70, transglutaninase-C, E-cadherin, VEGF, vWF. Both the prenatal and postnatal specimens of cleft lip and palate showed dysplastic proliferation of the basal cell layer, increased infiltration of melanocytes into mucosal epithelium, sebaceous gland hyperplasia ingrowing into the muscular tissue of lip and palate, and fatty infiltration into the submucosal deep connective tissue. The strong reactions of MMP-3 and HSP-70 were detected in the tissues of cleft lip and palate, especially increased in degenerating muscle bundles, while the immunostainings of PCNA and c-erb-B2 were weakly positive in the tissues of cleft lip and palate. These data suggest that the retrogressive tissue degeneration around the cleft areas persistently exist during the prenatal and postnatal period after cleft formation, and the sebaceous gland hyperplasia and fatty infiltration with the intense expression of MMP-3 and HSP-70 is closely related to the muscular degeneration around the cleft area.

• Applied Microscopy
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• v.31 no.2
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• pp.185-197
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• 2001

Human gastric adenocarcinomas are fixated with low energy of microwave (LEM) to study fixation effects in level of ultrastructure and antigenicity of the cancer. For the Ag-Ab reactions , the LEM fixated sdenocarcinomas are incorporated with monoclonal mouse anti-human p53 (IgG2b, kappa) and rabbit anti human cerbB-2. The retrieval of antigenicity are easily recognizable in the LEM fixated sections compared with that of frozen sections which show often diffused colour reactions. And the LEM fixation methods have preserved ultrastructures of the adenocarcinoma, but it was often difficult to maintain constancy in fixation effects. For the constancy, LEM was coupled with low concentration of chemical fixatives, such as glutaraldehyde (<1%) and $OsO_4$ (<0.5%). The results were acceptable, but there are tendencies that the adenocarcinoma requisitioned rather weak microwave energy to come into the optimal fixation effects. Therefore , cultured HeLa cells were fixated with lower energy of microwave than that used to the adenocarcinoma. The ultrastructures of the single HeLa cell have been preserved. The results may imply that a different energy levels of microwave are requisitioned in accordance with kinds of cells and tissues for the optimal fixation effects. It is reported and discussed that the fixation methods of LEM used in this work could be applied routinely to conceal a insufficient diffusion rate of chemical fixatives into some kinds of cancer without compromising the ultrastructures as well as to improve antigenic quality of frozen sections.

• Radiation Oncology Journal
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• v.34 no.1
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• pp.1-9
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• 2016

Overexpression of human epidermal growth factor receptor 2 (HER2) is found in about 20% of breast cancer patients. With treatment using trastuzumab, an anti-HER2 monoclonal antibody, systemic control is improved. Nonetheless, the incidence of brain metastasis does not be improved, rather seems to be increased in HER2-positive breast cancer. The mainstay treatment for brain metastases is radiotherapy. According to the number of metastatic lesions and performance status of patients, radiosurgery or whole brain radiotherapy can be performed. The concurrent use of a radiosensitizer further improves intracranial control. Due to its large molecular weight, trastuzumab has a limited ability to cross the blood-brain barrier. However, small tyrosine kinase inhibitors such as lapatinib, has been noted to be a promising agent that can be used as a radiosensitizer to affect HER2-positive breast cancer. This review will outline general management of brain metastases and will focus on preclinical findings regarding the radiosensitizing effect of small molecule HER2 targeting agents.

• Molecules and Cells
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• v.43 no.1
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• pp.34-47
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• 2020

The circadian clock regulates various physiological processes, including bone metabolism. The nuclear receptors Reverbs, comprising Rev-erbα and Rev-erbβ, play a key role as transcriptional regulators of the circadian clock. In this study, we demonstrate that Rev-erbs negatively regulate differentiation of osteoclasts and osteoblasts. The knockdown of Rev-erbα in osteoclast precursor cells enhanced receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation, as well as expression of nuclear factor of activated T cells 1 (NFATc1), osteoclast-associated receptor (OSCAR), and tartrate-resistant acid phosphatase (TRAP). The overexpression of Rev-erbα leads to attenuation of the NFATc1 expression via inhibition of recruitment of c-Fos to the NFATc1 promoter. The overexpression of Rev-erbα in osteoblast precursors attenuated the expression of osteoblast marker genes including Runx2, alkaline phosphatase (ALP), bone sialoprotein (BSP), and osteocalcin (OC). Rev-erbα interfered with the recruitment of Runx2 to the promoter region of the target genes. Conversely, knockdown of Rev-erbα in the osteoblast precursors enhanced the osteoblast differentiation and function. In addition, Rev-erbα negatively regulated osteoclast and osteoblast differentiation by suppressing the p38 MAPK pathway. Furthermore, intraperitoneal administration of GSK4112, a Rev-erb agonist, protects RANKL-induced bone loss via inhibition of osteoclast differentiation in vivo. Taken together, our results demonstrate a molecular mechanism of Rev-erbs in the bone remodeling, and provide a molecular basis for a potential therapeutic target for treatment of bone disease characterized by excessive bone resorption.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.499-510
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• 2006

Malignant tumors of the human salivary glands may arise from major or minor salivary glands. Adenoid cystic carcinoma (ACC) is the second most common malignant neoplasm in the salivary glands. ACC is occasionally highly aggressive tumor that readily invades adjacent tissues and metastasize to distant organs at early stages of the disease. Although ACC tends to grow slowly, treatment outcome may be poor due to wide local infiltration, perineural or intraneural spread and a propensity for hematogenous metastasis. Therefore, knowledge of cellular and molecular characteristics that influence the growth, survival and metastasis of tumor cells, is important for new treatment strategies of salivary ACC. I determined expressions of epiderma growth factor (EGF)-signaling molecules using surgical specimens of human ACCs. Protein expressions of EGF, transforming growth $factor(TGF)-{\alpha}$, EGF receptor (EGFR), phosphorylated EGFR (pEGFR), and human EGF receptor (HER)-2 were assessed in 18 cases of salivary ACC by immunohistochemical staining. Adjacent normal salivary tissues and mucosal tissues, uninvolved by the malignant tumor, served as internal controls. Most of the tumors, especially ACC with a tubulocribriform pattern, were positive for EGF signaling molecules. The overall percentages of the 18 specimens expressing EGF, $TGF-{\alpha}$, EGFR, pEGFR, and HER2 were 50, 89, 61, 61 and 83% respectively. Moreover, tumor-associated endothelial cells and infiltrating immune-related cells in the stroma of ACC, also expressed these biomarkers. Taken together, EGF-signaling molecules are actively expressed in salivary ACC. Therefore, we suggest that these biomarkers can be molecular targets for new treatment strategies of salivary tumors.

• Proceedings of the KOSOMBE Conference
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• v.1991 no.05
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• pp.43-46
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• 1991

In this study, peripheral auditory system has been modeled as a filter bank of overlaping bandpass filters, and auditory filter shape has been estimated by notch noise masking. The filter was centered at 1kHz, and noise level was set to 40dB SPL. Masker noise was generated by summing sinusoidal functions with random phase for very steep skirts. To estimate threshold we used two alternative forced choice with 500 msec of duration. We measured threshold with notch width at 0.05,0.1,0.2,0.3,0.4 and 0.5. The filter was asymmetric with steeper upper branch and its ERB was 168 - 192 Hz.

• Tuberculosis and Respiratory Diseases
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• v.79 no.4
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• pp.248-256
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• 2016

Somatic mutations that lead to hyperactivation of epidermal growth factor receptor (EGFR) signaling are detected in approximately 50% of lung adenocarcinoma in people from the Far East population and tyrosine kinase inhibitors are now the standard first line treatment for advanced disease. They have led to a doubling of progression-free survival and an increase in overall survival by more than 2 years. However, emergence of resistant clones has become the primary cause for treatment failure, and has created a new challenge in the daily management of patients with EGFR mutations. Identification of mechanisms leading to inhibitor resistance has led to new therapeutic modalities, some of which have now been adapted for patients with unsuccessful tyrosine kinase inhibitor treatment. In this review, we describe mechanisms of tyrosine kinase inhibitor resistance and the available strategies to overcoming resistance.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2008.04a
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• pp.77-86
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• 2008

It's been known that overexpression of the oncoprotein Her2 (eu/ErbB2), transmembrane receptor protein, occurs in human breast cancer. Her2-positive breast cancer patients who have Her2 overexpression show less therapeutic efficacy with enhanced metathesis and increased resistance to chemotherapy. So far, a humanized monoclonal antibody against Her2 protein called Herceptin is the only drug approved by Food and Drug Administration for treatment of Her2-overexpressing breast tumors. However, antibody therapy of Herceptin may not be ideal method for therapeutic intervention of Her2 protein expression. The therapeutic intervention of Her2 protein expression may be more efficiently achieved by inhibiting the expression of Her2 gene rather than by down-regulating the Her2 protein already overexpressed. Here, we found that the interaction of two proteins of ESX (an epithelial-restricted transcription factor) and DRIP130/CRSP130/Sur2 (a Ras-linked subunit of human mediator complexes) mediates the expression of Her2 gene. The association of ESX with Sur2 is mediated by a small hydrophobic face of 8-amino acid helix in ESX, suggesting that the ESX-Sur2 interaction can be a new novel target for Her2-positive cancer. The process to develop potent ESX-Sur2 interaction inhibitors targeting for Her2-positive cancer therapeutics will be discussed.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1609-1615
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• 2016

Breast cancer is one of among all cancers with increased incidence, high mortality rate, and high economic and social costs. The the most common type of cancer among females worldwide, breast cancer is actually the uncontrolled proliferation of cells which attain malignancy. Recently it has shown that breast cancer contributes 11% among all types of cancer diagnosed globally on an annual basis and it is one of the leading causes of death among women. The human epidermal growth factor receptor 2 (HER-2) is a receptor tyrosine-protein kinase erbB-2 normally involved in the proliferation and division of breast cells. In some abnormal cases the HER2 gene does not work correctly and makes too many copies of itself. HER2-positive (HER2+) breast cancers constitute an aggressive type of breast cancer and tend to grow faster and are more likely to spread. However, therapies that specifically target HER2, such as Herceptin$^{(R)}$ (traztuzumab), are very effective. HER2 targeted therapies, has significantly improved the therapeutic outcome for patients with HER2 positive breast cancer.