• Archives of Plastic Surgery
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• v.41 no.6
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• pp.654-660
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• 2014

Background Reactive oxygen species (ROS) damages cell molecules, and modifies cell signaling. The nuclear factor E2-related factor (Nrf2) is a critical transcription regulator, which protects cells against oxidative damage. Nrf2 expression is increased in a large number of cancers. However, little information has been reported regarding the expression of Nrf2 in skin cancers. Hence, we explored the expression of Nrf2 protein in skin cancers. Methods The Nrf2 protein expression in 24 specimens, including 6 malignant melanomas (MM), 6 squamous cell carcinomas (SCC), 6 basal cell carcinomas (BCC), and 6 normal skin tissues, was evaluated by western blotting. Immunohistochemical staining was performed. The expression of Kelch-like ECH-associated protein 1 (Keap1), the key regulator of Nrf2, was also analyzed by western blotting. Results Small interfering RNA transfection to the melanoma cell line G361 confirmed that an approximately 66 kDa band was the true Nrf2 band. The western blot revealed that the Nrf2 protein was definitely expressed in normal skin tissues, but the Nrf2 expression was decreased in MM, SCC, and BCC. Immunohistochemical examination showed that expression of Nrf2 was decreased in all skin cancer tissues compared to the normal skin tissues. Keap1 was not expressed in all malignant skin tumors and normal skin tissues by western blot. Conclusions ROS was increased in various types of cancers which proteins were highly expressed or underexpressed. This study demonstrated that the expression of Nrf2 protein was down-regulated in human malignant skin tumors. We suggest that decreased expression of Nrf2 is related to skin cancers.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1099-1104
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• 2014

Aims and Background: Ginsenoside Rh2, which exerts the potent anticancer action both in vitro and in vivo, is one of the most well characterized ginsenosides extracted from ginseng. Although its effects on cancer are significant, the underlying mechanisms remain unknown. In this study, we sought to elucidate possible links between ginsenoside Rh2 and phosphoglucose isomerase/autocrine motility factor (PGI/AMF). Methods: $KG1{\alpha}$, a leukemia cell line highly expressing PGI/AMF was assessed by western blot analysis and reverse transcription- PCR (RT-PCR) assay after transfection of a small interfering (si)-RNA to silence PGI/AMF. The effect of PGI/AMF on proliferation was measured by typan blue assay and antibody array. A cell counting kit (CCK)-8 and flow cytometry (FCM) were adopted to investigate the effects of Rh2 on PGI/AMF. The relationships between PGI/AMF and Rh2 associated with Akt, mTOR, Raptor, Rag were detected by western blot analysis. Results: KG1${\alpha}$ cells expressed PGI/AMF and its down-regulation significantly inhibited proliferation. The antibody array indicated that the probable mechanism was reduced expression of PARP, State1, SAPK/JNK and Erk1/2, while those of PRAS40 and p38 were up-regulated. Silencing of PGI/AMF enhanced the sensibility of $KG1{\alpha}$ to Rh2 by suppressing the expression of mTOR, Raptor and Akt. Conclusion: These results suggested that ginsenoside Rh2 suppressed the proliferation of $KG1{\alpha}$, the same as down-regulation of PGI/AMF. Down-regulation of PGI/AMF enhanced the pharmacological effects of ginsenoside Rh2 on KG1${\alpha}$ by reducing Akt/mTOR signaling.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.291-297
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• 2013

Notch1 has been reported to be highly expressed in triple-negative and other subtypes of breast cancer. Mutant p53 (R280K) is overexpressed in MDA-MB-231 triple-negative human breast cancer cells. The present study aimed to determine whether the mutant p53 can be a potent transcriptional activator of the Notch1 in MDA-MB-231 cells, and explore the role of this mutant p53-Notch1 axis in curcumin-induced apoptosis. We found that curcumin treatment resulted in an induction of apoptosis in MDA-MB-231 cells, together with downregulation of Notch1 and its downstream target, Hes1. This reduction in Notch1 expression was determined to be due to the decreased activity of endogenous mutant p53. We confirmed the suppressive effect of curcumin on Notch1 transcription by performing a Notch1 promoter-driven reporter assay and identified a putative p53-binding site in the Notch1 promoter by EMSA and chromatin immunoprecipitation analysis. Overexpression of mutant p53 increased Notch1 promoter activity, whereas knockdown of mutant p53 by small interfering RNA suppressed Notch1 expression, leading to the induction of cellular apoptosis. Moreover, curcumin-induced apoptosis was further enhanced by the knockdown of Notch1 or mutant p53, but it was decreased by the overexpression of active Notch1. Taken together, our results demonstrate, for the first time, that Notch1 is a transcriptional target of mutant p53 in breast cancer cells and suggest that the targeting of mutant p53 and/or Notch1 may be combined with a chemotherapeutic strategy to improve the response of breast cancer cells to curcumin.

• Journal of Life Science
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• v.18 no.11
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• pp.1485-1492
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• 2008

Prostaglandin $A_2$ ($PGA_2$), one of cyclopentenone PGs, induced both apoptosis and heme oxygenase (HO)-1 expression in U2OS cells. $PGA_2$-induced apoptosis was not perturbed by either over-expression or knock-down of HO-1, whereas $H_2O_2$-induced cell death was inversely modulated by the expression level of HO-1. In addition, N-acetyl-L-cysteine (NAC), a thiol antioxidant, blocked both apoptosis and HO-1 expression induced by $PGA_2$. But, non-thiol antioxidants like butylated hydorxyanisole (BHA) and ascorbic acid did not block either apoptosis or HO-1-induction. Taken together, these results suggest that $PGA_2$ induces both apoptosis and HO-1 expression, which are critically related to the thiol- reactivity of $PGA_2$, but not oxidative stress, and HO-1 expression may be independent or functionally located downstream of apoptosis by $PGA_2$ without contribution to apoptosis progression.

• Journal of Life Science
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• v.23 no.1
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• pp.137-142
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• 2013

Human adipose-derived mesenchymal stem cells (hMSCs) are highly useful for vascular regeneration of injured or inflamed tissue. Lipopolysaccharide (LPS) is a potent activator of macrophages and stimulates macrophages to release inflammatory cytokines. In the present study, we explored the role of LPS-activated macrophages in the differentiation of hMSCs to smooth muscle cells (SMCs). We demonstrated that conditioned medium from LPS-induced macrophages (LPS CM) stimulates differentiation of hMSCs to SMCs, as evidenced by increased expression of smooth muscle-specific markers, including alpha-smooth muscle actin (${\alpha}$-SMA), smooth muscle-myosin heavy chain, and calponin. LPS induced the secretion of $PGF2{\alpha}$ from macrophages, and $PGF2{\alpha}$ treatment stimulated expression levels of SMC-specific markers in hMSCs. Furthermore, small interfering RNA-mediated silencing of the $PGF2{\alpha}$ receptor inhibited LPS CM-stimulated ${\alpha}$-SMA expression. These results suggest that LPS-activated macrophages promote differentiation of hMSCs to SMCs through a $PGF2{\alpha}$-dependent mechanism.

• Journal of Life Science
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• v.34 no.1
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• pp.37-47
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• 2024

FUN14 domain-containing protein 1 (FUNDC1), an outer mitochondrial membrane protein, contributes to removal of damaged mitochondria through mitophagy. In this study, to elucidate the role of the FUNDC1 in the amyloid beta peptide (A_β)-induced neuropathy, changes in the degree of mitochondrial dysfunction and cell injury caused by A_β treatment were examined in the HT-22 neuronal cells in which the FUNDC1 expression was transiently silenced or overexpressed. We found that A_β treatment causes a time-dependent decrease of the FUNDC1 expression. In the A_β-treated cells, there were a drop in MTT reduction ability, depletion of cellular ATP, disruption of mitochondrial membrane potential, stimulation of cellular ROS production, and increased mitochondrial Ca²⁺ load. Activation of caspase-3 and induction of apoptotic cell death were also observed. Transient silencing of the FUNDC1 expression by transfection with the FUNDC1 small interfering RNA per se caused mitochondrial dysfunction and apoptotic cell death like the effect of A_β treatment. Conversely, in cells in which the FUNDC1 was transiently overexpressed by FUNDC1-Myc transfection, overexpression itself had no effect on the mitochondrial functional integrity and cell survival but showed a significant prevention effect against mitochondrial and cell injury caused by A_β treatment. Overall, these results suggest that the FUNDC1 is importantly involved in the A_β-induced mitochondrial dysfunction and cell injury in the HT-22 neuronal cells.

• International Journal of Oncology
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• v.54 no.6
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• pp.2169-2178
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• 2019

Forkhead box A1 (FOXA1) functions as a tumor suppressor gene or an oncogene in various types of cancer; however, the distinct function of FOXA1 in colorectal cancer is unclear. The present study aimed to evaluate whether FOXA1 affects the oncogenic behavior of colorectal cancer cells, and to investigate its prognostic value in colorectal cancer. The impact of FOXA1 on tumor cell behavior was investigated using small interfering RNA and the pcDNA6-myc vector in human colorectal cancer cell lines. To investigate the role of FOXA1 in the progression of human colorectal cancer, an immunohistochemical technique was used to localize FOXA1 protein in paraffin-embedded tissue blocks obtained from 403 patients with colorectal cancer. Tumor cell apoptosis and proliferation were evaluated using a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and Ki-67 immunohistochemical staining, respectively. FOXA1 knockdown inhibited tumor cell invasion in colorectal cancer cells, and induced apoptosis and cell cycle arrest. FOXA1 knockdown activated cleaved caspase-poly (ADP-ribose) polymerase, upregulated the expression of p53 upregulated modulator of apoptosis, and downregulated BH3 interacting domain death agonist and myeloid cell leukemia-1, leading to the induction of apoptosis. FOXA1 knockdown increased the phosphorylation level of signal transducer and activator of transcription-3. By contrast, these results were reversed following the overexpression of FOXA1. The overexpression of FOXA1 was associated with differentiation, lymphovascular invasion, advanced tumor stage, depth of invasion, lymph node metastasis and poor survival rate. The mean Ki-67 labeling index value of FOXA1-positive tumors was significantly higher than that of FOXA1-negative tumors. However, no significant association was observed between the expression of FOXA1 and the mean apoptotic index value. These results indicate that FOXA1 is associated with tumor progression via the modulation of tumor cell survival in human colorectal cancer.

• International Journal of Stem Cells
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• v.15 no.3
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• pp.311-323
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• 2022

Background and Objectives: Human mesenchymal stem cells (MSCs) are emerging as a treatment for atopic dermatitis (AD), a chronic inflammatory skin disorder that affects a large number of people across the world. Treatment of AD using human umbilical cord blood-derived MSCs (hUCB-MSCs) has recently been studied. However, the mechanism underlying their effect needs to be studied continuously. Thus, the objective of this study was to investigate the immunomodulatory effect of epidermal growth factor (EGF) secreted by hUCB-MSCs on AD. Methods and Results: To explore the mechanism involved in the therapeutic effect of MSCs for AD, a secretome array was performed using culture medium of hUCB-MSCs. Among the list of genes common for epithelium development and skin diseases, we focused on the function of EGF. To elucidate the effect of EGF secreted by hUCB-MSCs, EGF was downregulated in hUCB-MSCs using EGF-targeting small interfering RNA. These cells were then co-cultured with keratinocytes, Th2 cells, and mast cells. Depletion of EGF disrupted immunomodulatory effects of hUCB-MSCs on these AD-related inflammatory cells. In a Dermatophagoides farinae-induced AD mouse model, subcutaneous injection of hUCB-MSCs ameliorated gross scoring, histopathologic damage, and mast cell infiltration. It also significantly reduced levels of inflammatory cytokines including interleukin (IL)-4, tumor necrosis factor (TNF)-α, thymus and activation-regulated chemokine (TARC), and IL-22, as well as IgE levels. These therapeutic effects were significantly attenuated at all evaluation points in mice injected with EGF-depleted hUCB-MSCs. Conclusions: EGF secreted by hUCB-MSCs can improve AD by regulating inflammatory responses of keratinocytes, Th2 cells, and mast cells.

• Journal of Life Science
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• v.21 no.2
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• pp.183-193
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• 2011

Migration and differentiation of mesenchymal stem cells are crucial for tissue regeneration in response to injury. Sphingosine-1-phosphate (S1P) is a bioactive lipid that regulates a variety of biological processes, including proliferation, survival, differentiation and motility. In the present study, we determined the role of S1P in migration and differentiation of human bone marrow-derived mesenchymal stem cells (BMSCs). S1P stimulated migration of BMSCs in a dose- and time-dependent manner, and pre-incubation of the cells with pertussis toxin completely abrogated S1P-induced migration, suggesting involvement of Gi-coupled receptors in S1P-induced cell migration. S1P elicited elevation of intracellular concentration of $Ca^{2+}$ ($[Ca^{2+}]_i$) and pretreatment with VPC23019, an antagonist of $S1P_1/S1P_3$, blocked S1P-induced migration and increase of $[Ca^{2+}]_i$. Small interfering RNA-mediated knockdown of endogenous $S1P_1$ attenuated S1P-induced migration of BMSCs. Furthermore, S1P treatment induced expression of $\alpha$-smooth muscle actin ($\alpha$-SMA), a smooth muscle marker, and pretreatment with VPC23019 abrogated S1P-induced $\alpha$-SMA expression. S1P induced phosphorylation of p38 mitogen-activated protein kinase (MAPK), and pretreatment of cells with SB202190, an inhibitor of p38 MAPK, or adenoviral overexpression of a dominant-negative mutant of the p38 MAPK blocked S1P-induced cell migration and $\alpha$-SMA expression. Taken together, these results suggest that S1P stimulates migration and smooth muscle differentiation of BMSCs through an $S1P_1$-p38 MAPK-dependent mechanism.

• Journal of Life Science
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• v.29 no.4
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• pp.402-409
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• 2019

Korean red ginseng made from steaming and drying fresh ginseng has long been used as a traditional herbal medicine due to its effects on the immune, endocrine, and central nerve systems and its anti-inflammatory activity. In this study, we investigated the molecular mechanism responsible for the anti-inflammatory effects of a formulated Korean red ginseng extract (RGE) in response to lipoteichoic acid (LTA), a cell wall component of gram-positive bacteria. RGE inhibited LTA-induced nitric oxide (NO) secretion and inducible nitric oxide synthase (iNOS) expression in BV-2 microglial cells, without affecting cell viability. RGE also inhibited nuclear translocation of nuclear factor kappa B ($NF-{\kappa}B$) p65 and degradation of $I{\kappa}B-{\alpha}$. In addition, RGE increased the expression of heme oxygenase-1 (HO-1) in a dose-dependent manner, and the inhibitory effect of RGE on iNOS expression was abrogated by small interfering RNA-mediated knockdown of HO-1. Moreover, RGE induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. Furthermore, the phosphoinositide-3-kinase (PI-3K) inhibitor and mitogen-activated protein kinase (MAPK) inhibitors suppressed RGE-mediated expression of HO-1, and RGE enhanced the phosphorylation of Akt, extracellular signal-regulated kinases (ERKs), p38, and c-JUN N-terminal kinases (JNKs). These results suggested that RGE suppressed the production of NO, a proinflammatory mediator, by inducing HO-1 expression via PI-3K/Akt- and MAPK-dependent signaling in LTA-stimulated microglia. The findings indicate that RGE could be used for the treatment of neuroinflammation induced by grampositive bacteria and that it may have therapeutic potential for various neuroinflammation-associated disorders.