• Journal of Life Science
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• v.21 no.12
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• pp.1795-1803
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• 2011

Non-alcoholic fatty liver disease accompanies the rise in the prevalence of obesity, diabetes and the tendency toward high-fat dietary habits. Specifically, the higher prevalence of non-alcoholic fatty liver disease in men and postmenopausal women seems to be caused by the protective effects of estrogen against liver fibrosis, or lack thereof. There are no effective preventive therapies for liver diseases because the mechanisms underlying the progression of fatty liver diseases to chronic liver diseases and the protective effects of estrogen against fibrogenesis remain unclear. Recently, it has been reported that the hedgehog signaling pathway plays an important role in the progression of chronic liver diseases. Hedgehog, a morphogen regulating embryonic liver development, is expressed in injured livers but not in adult healthy livers. The level of hedgehog expression parallels the stages of liver diseases. Hedgehog induces myofibroblast activation and hepatic progenitor cell proliferation and leads to excessive liver fibrosis, whereas estrogen inhibits the activation of hepatic stellate cells to myofibroblasts and prevents liver fibrosis. Although the mechanism underlying the opposing actions of hedgehog and estrogen on liver fibrosis remain unclear, the suppressive effects of estrogen on the expression of osteopontin, a profibrogenic extracellular matrix protein and cytokine, and the inductive effects of hedgehog on osteopontin transcription suggest that estrogen and hedgehog are associated with liver fibrosis regulation. Therefore, further research on the estrogen-mediated regulatory mechanisms underlying the hedgehog-signaling pathway can identify the mechanism underlying liver fibrogenesis and contribute to developing therapies for preventing the progression of fibrosis to chronic liver diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6201-6206
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• 2015

The epithelial-mesenchymal transition (EMT) is a cellular process though which an epithelial phenotype can be converted into a phenotype of mesenchymal cells. Under physiological conditions EMT is important for embryogenesis, organ development, wound repair and tissue remodeling. However, EMT may also be activated under pathologic conditions, especially in carcinogenesis and metastatic progression. Major signaling pathways involved in EMT include transforming growth factor ${\beta}(TGF-{\beta})$, Wnt, Notch, Hedgehog and other signaling pathways. These pathways are related to several transcription factors, including Twist, Smads and zinc finger proteins snail and slug. These interact with each other to provide crosstalk between the relevant signaling pathways. This review lays emphasis on studying the relationship between EMT and signaling pathways in carcinogenesis and metastatic progression.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.1
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• pp.1-5
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• 2017

Bone morphogenetic protein 2 (BMP2) plays an important role in the development of bone and cartilage. It is involved in the hedgehog pathway, TGF beta signaling pathway, and in cytokine-cytokine receptor interaction. It is involved also in cardiac cell differentiation and epithelial to mesenchymal transition. In this study, We expressed human BMP2 (hBMP2) recombinant protein using Baculovirus Expression Vector System (BEVS) in Sf9 insect cells. The hBMP2 cDNA was cloned into baculovirus transfer vector, pBacgus-4x-1 and recombinant baculovirus was screened out through X-gal and GUS-fusions assay. Western blot analysis shown that molecular weight of hBMP2 recombinant protein was about 44.71 kDa.

• Molecules and Cells
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• v.41 no.3
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• pp.224-233
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• 2018

Primary cilia are solitary, non-motile, axonemal microtubule-based antenna-like organelles that project from the plasma membrane of most mammalian cells and are implicated in transducing hedgehog signals during development. It was recently proposed that aberrant SHH signaling may be implicated in the progression of idiopathic pulmonary fibrosis (IPF). However, the distribution and role of primary cilia in IPF remains unclear. Here, we clearly observed the primary cilia in alveolar epithelial cells, fibroblasts, and endothelial cells of human normal lung tissue. Then, we investigated the distribution of primary cilia in human IPF tissue samples using immunofluorescence. Tissues from six IPF cases showed an increase in the number of primary cilia in alveolar cells and fibroblasts. In addition, we observed an increase in ciliogenesis related genes such as IFT20 and IFT88 in IPF. Since major components of the SHH signaling pathway are known to be localized in primary cilia, we quantified the mRNA expression of the SHH signaling components using qRT-PCR in both IPF and control lung. mRNA levels of SHH, the coreceptor SMO, and the transcription factors GLI1 and GLI2 were upregulated in IPF compared with control. Furthermore, the nuclear localization of GLI1 was observed mainly in alveolar epithelia and fibroblasts. In addition, we showed that defective KIF3A-mediated ciliary loss in human type II alveolar epithelial cell lines leads to disruption of SHH signaling. These results indicate that a significant increase in the number of primary cilia in IPF contributes to the upregulation of SHH signals.

• BMB Reports
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• v.45 no.8
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• pp.427-432
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• 2012

Primary cilia, single hair-like appendage on the surface of the most mammalian cells, were once considered to be vestigial cellular organelles for a past century because of their tiny structure and unknown function. Although they lack ancestral motility function of cilia or flagella, they share common ground with multiciliated motile cilia and flagella on internal structure such as microtubule based nine outer doublets nucleated from the base of mother centrioles called basal body. Making cilia, ciliogenesis, in cells depends on the cell cycle stage due to reuse of centrioles for cell division forming mitotic spindle pole (M phase) and assembling cilia from basal body (starting G1 phase and maintaining most of interphase). Ciliary assembly required two conflicting processes such as assembly and disassembly and balance between these two processes determines the length of cilia. Both process required highly conserved transport system to supply needed substance to grow tip of cilia and bring ciliary turnover product back to the base of cilia using motor protein, kinesin and dynein, and transport protein complex, IFT particles. Disruption of ciliary structure or function causes multiple human disorder called ciliopathies affecting disease of diverse ciliated tissues ranging from eye, kidney, respiratory tract and brain. Recent explosion of research on the primary cilia and their involvement on animal development and disease attracts scientific interest on how extensively the function of cilia related to specific cell physiology and signaling pathway. In this review, I introduce general features of primary cilia and recent progress in understanding of the ciliary length control and signaling pathways transduced through primary cilia in vertebrates.

• BMB Reports
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• v.51 no.3
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• pp.126-133
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• 2018

Hippo signaling plays critical roles in regulation of tissue homeostasis, organ size, and tumorigenesis by inhibiting YES-associated protein (YAP) and PDZ-binding protein TAZ through MST1/2 and LATS1/2 pathway. It is also engaged in cross-talk with various other signaling pathways, including WNT, BMPs, Notch, GPCRs, and Hedgehog to further modulate activities of YAP/TAZ. Because YAP and TAZ are transcriptional coactivators that lack DNA-binding activity, both proteins must interact with DNA-binding transcription factors to regulate target gene's expression. To activate target genes involved in cell proliferation, TEAD family members are major DNA-binding partners of YAP/TAZ. Accordingly, YAP/TAZ were originally classified as oncogenes. However, YAP might also play tumor-suppressing role. For example, YAP can bind to DNA-binding tumor suppressors including RUNXs and p73. Thus, YAP might act either as an oncogene or tumor suppressor depending on its binding partners. Here, we summarize roles of YAP depending on its DNA-binding partners and discuss context-dependent functions of YAP/TAZ.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.2
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• pp.97-108
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• 2011

Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.73-79
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• 2018

The primary cilium protrudes from the cell body like a bio-antenna that has many receptors, channels and signaling molecules to sense and response to external stimuli. The external environment such as ultraviolet irradiation, temperature, humidity, gravity and shear stress always influences skin. Skin responds to external stimuli and differentiates by making melanin, collagen and horny layer. Ciliogenesis participates in developmental processes of skin, such as keratinocyte differentiation and hair formation. And it was reported that skin pigmentation was inhibited when ciliogenesis was induced by sonic hedgehog-smoothened-GLI2 signaling. When skin is exposed to ultraviolet irradiation, alpha-melanocyte stimulating hormones (${\alpha}$-MSH) increase melanin synthesis through activation of the cAMP pathway in melanocytes. We observed that ${\alpha}$-MSH and cAMP production inducers inhibited ciliogenesis of melanocytes. Therefore, we thought that regulation of ciliogenesis is potential candidate target for the development of agents to treat undesirable hyperpigmentation of skin. As a result, we found out that an ethanol extract of Glycyrrhiza glabra (EGG) root and 3,4,5-trimethoxy cinnamate thymol ester (TCTE, Melasolv) significantly inhibit melanin synthesis of normal human melanocyte by inducing primary cilium formation. This study proposed new theory to regulate skin pigmentation and cosmetic components for skin whitening.

• Archives of Plastic Surgery
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• v.50 no.4
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• pp.384-388
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• 2023

Gorlin-Goltz syndrome, also known as nevoid basal cell carcinoma syndrome, is an autosomal dominant disease characterized by multisystemic developmental defects caused by pathogenic variants such as patched-1 (PTCH1) gene variants and/or SUFU gene variants. The presence of either two main criteria or one major and two minor criteria are required for the diagnosis of Gorlin-Goltz syndrome. Recently, a major criterion for molecular confirmation has also been proposed. In this article, we report the case of an 80-year-old male who was admitted at our department for multiple brown-to-black papules and plaques on the entire body. He was diagnosed with Gorlin-Goltz syndrome with clinical, radiologic, and pathologic findings. While the diagnosis was made based on the clinical findings in general, confirmation of the genetic variants makes an ideal diagnosis and suggests a new treatment method for target therapy. We requested a genetic test of PTCH1 to ideally identify the molecular confirmation in the hedgehog signaling pathway. However, no pathogenic variants were found in the coding region of PTCH1, and no molecular confirmation was achieved.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4001-4005
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• 2012

Backgrouds: The hedgehog (Hh) signaling pathway is composed of patched (PTCH) and smoothened (SMO), two transmembrane proteins, and downstream glioma-associated oncogene homolog (Gli) transcription factors. Hh signaling plays a pathological role in the occurrence and development of various cancers. Methods: To investigate the expression of SMO protein in colon cancer and its association with clinicopathological parameters and postoperative liver metastasis, immunohistochemistry was performed with paraffin-embedded specimens of 96 cases. Relationships between SMO protein expression and clinicopathological parameters, postoperative liver metastasis were analyzed. Results: IHC examination showed that SMO protein expression was significantly increased in colon cancer tissues compared to normal colon tissues (P = 0.042), positively related to lymph node metastases (P = 0.018) and higher T stages (P = 0.026). Postoperative live metastasis-free survival was significantly longer in the low SMO expression group than in those with high SMO expression ($48.7{\pm}8.02$ months vs $28.0{\pm}6.86$ months, P=0.036). Multivariate analysis showed SMO expression level to be an independent prognostic factor for postoperative live metastasis-free survival (95% confidence interval [CI] =1.46-2.82, P = 0.008). Conclusions: Our results suggest that in patients with colon cancer, the SMO expression level is an independent biomarker for postoperative liver metastasis, and SMO might play an important role in colon cancer progression.