• Journal of Life Science
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• v.21 no.11
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• pp.1625-1630
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• 2011

Heme oxygenase-1 (HO-1) is a stress-responsive protein that is known to regulate cellular functions such as cell proliferation, inflammation, and apoptosis. In this study, we investigated the role of NADPH oxidase on the expression of HO-1 in human liver hepatoma cell line HepG2. Diphenyleneiodonium (DPI), an NADPH oxidase inhibitor, markedly inhibited HO-1 expression and the nuclear translocation of transcription factor Nrf2 in cobalt protoporphyrin (CoPP) or hemin-treated HepG2 cells. Similarly, the knockdown of $p47^{phox}$, a cytosolic factor for NADPH oxidase activity, by siRNA inhibited the CoPP-induced expression of HO-1. In addition, GSHmee, an intracellular antioxidant, blocked the expression of HO-1 in CoPP-treated cells. Based on these results, we conclude that the blockage of NADPH oxidase with DPI or $p47^{phox}$ siRNA inhibits CoPP-induced HO-1 expression in HepG2 cells, and also suggest that the expression of HO-1 in CoPP-induced HepG2 cells is associated with increase of intracellular ROS by NADPH oxidase activity.

• Journal of Life Science
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• v.27 no.2
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• pp.149-154
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• 2017

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-hodgkin lymphoma. Advances in the chemotherapeutic treatment of this disease have improved the outcomes of DLBCL; nonetheless, many patients still die of DLBCL, and therefore, a better understanding of this disease and identification of novel therapeutic targets are urgently required. In a recent gene expression profiling study, PDE (phosphodiesterase) 4B was found to be overexpressed in chemotherapy-resistant tumors. The major function of PDE4B is to inactivate the second messenger cyclic 3',5' monophosphate (cAMP) by catalyzing the hydrolysis of cAMP to 5'AMP. It is known that cAMP induces cell cycle arrest and/or apoptosis in B cells, and PDE4B abolishes cAMP's effect on B cells. However, the mechanism by which PDE4B is overexpressed remains unclear. Here, we show that the aberrant expression of miRNA may be associated with the overexpression of this gene. The PDE4B 3' untranslated region (UTR) has three functional binding sites of miR-23b, as confirmed by luciferase reporter assays. Interestingly, miR-23b-binding sites were evolutionarily conserved from humans to lizards, implying the critical role of PDE4B-miR-23b interaction in cellular physiology. The ectopic expression of miR-2 3b repressed PDE4B mRNA levels and enhanced intracellular cAMP concentrations. Additionally, miR-23b expression inhibited cell proliferation and survival of DLBCL cells only in the presence of forskolin, an activator of adenylyl cyclase, suggesting that miR-23b's effect is via the downregulation of PDE4B. These results together suggest that miR-23b could be a therapeutic target for overcoming drug resistance by repressing PDE4B in DLBCL.

• Tuberculosis and Respiratory Diseases
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• v.62 no.1
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• pp.33-42
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• 2007

Background: Heme oxygenase-1 (HO-1) is known to modulates the cellular functions, including cell proliferation and apoptosis. It is known that a high level of HO-1 expression is found in many tumors, and HO-1 plays an important role in rapid tumor growth on account of its antioxidant and antiapoptotic effects. Cisplatin is a widely used anti-cancer agent for the treatment of lung cancer. However, the development of resistance to cisplatin is a major obstacle to its use in clinical treatment. We previously demonstrated that inhibiting HO-1 expression through the transcriptional activation of Nrf2 induces apoptosis in A549 cells. The aim of this study was to determine of the inhibiting HO-1 enhance the chemosensitivity of A549 cells to cisplatin. Materials and Methods: The human lung cancer cell line, A549, was treated cisplatin, and the cell viability was measured by a MTT assay. The change in HO-1, Nrf2, and MAPK expression after the cisplatin treatment was examined by Western blotting. HO-1 inhibition was suppressed by ZnPP, which is a specific pharmacologic inhibitor of HO activity, and small interfering RNA (siRNA). Flow cytometry analysis and Western blot were performed in to determine the level of apoptosis. The level of hydrogen peroxide ($H_2O_2$) generation was monitored fluoimetrically using 2',7'-dichlorofluorescein diacetate. Results: The A549 cells showed more resistance to the cisplatin treatment than the other cell lines examined, whereas cisplatin increased the expression of HO-1 and Nrf2, as well as the phosphorylation of MAPK in a time-dependent fashion. Inhibitors of the MAPK pathway blocked the induction of HO-1 and Nrf2 by the cisplatin treatment in A549 cells. In addition, the cisplatin-treated A549 cells transfected with dither the HO-1 small interfering RNA (siRNA) or ZnPP, specific HO-1 inhibitor, showed in a more significantly decrease in viability than the cisplatin-only-treated group. The combination treatment of ZnPP and cisplatin caused in a marked increase in the ROS generation and a decrease in the HO-1 expression. Conclusion: Cisplatin increases the expression of HO-1, probably through the MAPK-Nrf2 pathway, and the inhibition of HO-1 enhances the chemosensitivity of A549 cells to cisplatin.

• The Journal of Korean Obstetrics and Gynecology
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• v.15 no.4
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• pp.61-75
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• 2002

Recombinant human $interleukin-1{\beta}$ $(rhIL-1{\beta})$ regulates several activities of the osteoblast cells derived from mouse calvarial bone explants in vitro. $rhIL-1{\beta}$ stimulated cellular proliferation and the synthesis of prostaglandin $E_2(PGE_2)$ and plasminogen activator activity in the cultured cells in a dose-dependent manner. However, the induction of osteocalcin synthesis and alkaine phosphatase activity in response to vitamine D, two characteristics of the osteoblast phenotype, were antagonized by $rhIL-1{\beta}$ over a similar dose range. This study supports the role of $IL-1{\beta}$ in the pathological modulation of bone cell metabolism, with regard to implication in the pathogenesis of osteoporosis by $IL-1{\beta}$. When the mouse calvarial bone cells were used, the bone resorption induced by $IL-1{\beta}$ was strongly inhibited by calcitonin treatment, indicating osteoclast-mediated bone resorption. On the other hand, the medicinal extracts of Taeyoungjon-Jahage (T.Y.J-J.H.G extracts) was tested for whether they could inhibit $IL-1{\beta}-induced$ $PGE_2$ production. Cell viability was not significantly affected by treatment with the indicated concentration of the extracts. The T.Y.J.-J.H.G. extracts were shown to have the inhibitory effects against the synthesis of $PGE_2$. We also examined the effect of the pretreatment with a various concentrations of the T.Y.J.-J.H.G. extracts then treated the $PGE_2-induction$ agents. Pretreatment of the T.Y.J.-J.H.G. extracts for 1 h, which by itself had little effect on cell survival, did not enhance the synthesis of $PGE_2$. Furthermore, the T.Y.J-J.H.G. extracts were shown to have the protective effects against plasminogen dependent fibrinolysis induced by the bone resorption agents of $IL-1{\beta}$. Pretreatment of the T.Y.J.-J.H.G. extracts for 1 h did not enhance the plasminogen dependent fibrinolysis. Finally, calcitonin showed the inhibitory activity the $IL-1{\beta}-stimulated$ bone resorption in the mouse calvarial bone cells having both of the osteoblast and osteoclast cells. Seemingly, pretreatment of the T.Y.J.-J.H.G. extracts for 1 h reduced the bone resorption. These results clearly indicated that calcitonin and T.Y.J.-J.H.G. extracts play key roles in inhibition of the osteoclast-mediated bone resorption.

• Radiation Oncology Journal
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• v.12 no.3
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• pp.271-284
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• 1994

Purpose : Phospholipase C(PLC) isozymes play significant roles in transmembrane signal transduction. PLC-${\gamma}1$ acts as the intracellular effector in signal transduction for cellular proliferation and differentiation. Ras oncoprotein is also involved in cell growth. We determined the biological significance of PLC and ras oncoprotein in regeneration following radiation and the effect of different modes of administration of 5-FU. Materials and Methods : To determine the effect of the administration mode of 5-FU on the regeneration of intestinal mucosa of rats following radiation, we compared the expression of PLC and ras oncoprotein in six groups. Group I had no treatment. Group II received radiation(8 Gy) only. Group III received radiation(8 Gy) and 5-FU(150mg/kg) continuous intravenous (iv) infusion for 12 hours. Group IV received radiation(8 Gy) and 5-FU(750mg/kg) iv bolus injection. Group V received only 5-FU(150mg/kg) continuous iv infusion for 12 hours, Group VI received only 5-FU (150mg/kg) iv bolus injection. Through immunoblotting and immunohistochemistry, we examined the expression of PLC and ras oncoprotein in rat jejunum at 96 hours after radiation or 5-FU administration and at 120 hours after radiation and 5-FU adminstration. We also investigated the histological findings using hematoxylin and eosin stain. Results : In the immunohistochemistry study, PLC-${\gamma}1$ expression was the highest in group III followed by groups II and VI in that order and was weakly positive in groups V and VI. PLC-${\gamma}1$ was hardly detected in the control group. The expression of ras oncoprotein was the same as the PLC-${\gamma}1$ expression for all groups. These results were confirmed by the histological findings regarding the mucosal regeneration. In the immunoblotting analysis, PLC-${\gamma}1$ expression was the highest in group III followed by group IV and II in that order. This difference between the immunoblotting and immunohistochemistry study was due to the high expression of PLC-${\gamma}1$ on the damaged surface epithelium rather than to its expression in the regeneration region as observed in the immunohistochemistry study for group IV. The expression of PLC-${\delta}1$ was positive only in group V and VI, which received both radiation and 5-FU, and the expression of PLC-${\beta}1$ was negligible for all groups. Conclusion : These results suggest that PLC-${\gamma}1$ mediated signal transduetion and ras oncoprotein may have a significant role in mucosal regeneration after radiation, and that continuous iv infusion of 5-FU may induce active regeneration in intestinal mucosa following radiation. In addition, the expression of PLC-${\delta}1$ in combined group of radiation and 5-FU implies that PLC-${\delta}1$ may be involved in signal transduction mediated by concerted action between radiation and 5-FU.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.3
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• pp.163-174
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• 2009

Objectives: Members of the immortalization-upregulated protein (IMUP) family are nuclear proteins implicated in SV40-mediated immortalization and cellular proliferation, but the mechanisms by which their expression is regulated are still unknown in placenta. To investigate to expression and functions of IMUPs in placenta, we conducted to compare IMUPs expression in normal and preeclamptic placenta tissues and analyzed the function of IMUP-2 in HTR-8/SVneo trophoblast cells after IMUP-2 gene transfection. Methods: The expression of IMUPs was analyzed in placental tissues from the following groups of patients (none underwent labor): 1) term normal placenta (n=15); 2) term with preeclamptic placeneta (n=15); and 3) pre-term with preeclamptic placenta (n=11) using semi-quantitative RT-PCR, RNA in situ hybiridization, immunohistochemistry, and Western blot. In order to evaluate the function of IMUP-2 in HTR-8/SVneo trophoblast cells, IMUP-2 plasmids were transfected into HTR-8/SVneo trophoblast cells for 24 hours. Results: We observed that IMUPs are mainly expressed in the syncytiotrophoblasts and syncytial knot of placental villi. The expression of IMUP-1 was not differences between normal and preeclamptic placenta tissues. However, IMUP-2 expression was significantly higher in preterm preeclamptic placenta tissues than in normal placenta tissues without labor (p<0.001). Furthermore, we confirmed overexpression of IMUP-2 induced apoptosis in HTR-8/SVneo trophoblast cells through up-regulation of pro-apoptotic proteins. Conclusions: These results suggest that the expression of IMUP-2 is involved in placental development as well as increased IMUP-2 expression is associated with preeclampsia through the inducing of trophoblast apoptosis.

• Journal of Life Science
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• v.31 no.9
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• pp.827-833
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• 2021

Dendropanax morbiferus leaves (DPL) has been used as a medicine since ancient times in various diseases such as inflammation, diabetes, and cancer. In particular, it has been found to have anticancer effects on several types of cancer cells, but the anticancer effect on breast cancer cells SK-BR-3 has not yet been revealed. Therefore, in this study, DPL caused proliferation inhibition in breast cancer cells SK-BR-3 and the anticancer effect by inducing apoptosis was confirmed, through an in vitro experiment. In order to examine the effect of DPL on cell viability, MTT assay was performed to confirm a significant decrease in the concentration of cell viability. DAPI staining was performed to examine the effect of DPL on cellular morphological changes and increase of apoptotic bodies. To supplement this, an increase in the apoptosis rate was also confirmed through flow cytometry after staining with annexin V/PI. Western blot was performed to confirm apoptosis-related proteins. DPL increased the expression of Cleaved-PARP, Bax whereas decreased the expression of Bcl-2. Changes in the expression levels of MAPK pathway proteins p-ERK1/2, p-JNK, and p-p38 were also confirmed, and a significant increase in p-p38 was observed. These results indicated that DPL induced apoptosis, through p-p38 MAPK signal pathway in SK-BR-3 breast cancer cells.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.150-161
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• 2022

Purpose: To determine the effects of the microgroove-fibronectin complex surface on the expression of various genes related to cellular activity in human gingival fibroblasts. Materials and Methods: Smooth titanium specimens (NE0), acid-treated titanium specimens (E0), microgroove and acid-treated titanium specimens (E60/10), fibronectin-fixed smooth titanium specimens (NE0FN), acid-treated and fibronectin-immobilized titanium specimens (E0FN), and microgroove and acid-treated titanium specimens immobilized with fibronectin (E60/10FN) were prepared. Real-time polymerase chain reaction experiments were conducted on 44 genes related to cell behavior of human gingival fibroblasts. Results: Adhesion and proliferation of human gingival fibroblast on microgroove-fibronectin complex titanium were activated through four types of signaling pathway. Integrin α5, Integrin β1, Integrin β3, Talin-2, which belong to the focal adhesion pathway, AKT1, AKT2, NF-κB, which belong to the PI3K-AKT signaling pathway, MEK2, ERK1, ERK2, which belong to the MAPK signaling pathway, and Cyclin D1, CDK4, CDK6 genes belonging to the cell cycle signaling pathway were upregulated on the microgroove-fibronectin complex titanium surface (E60/10FN). Conclusion: The microgroove-fibronectin complex titanium surface can up-regulate various genes involved in cell behavior.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.186-194
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• 2004

Purpose: Membranoproliferative glomeulonephritis(MPGN) has been diagnosed in an increasing number of asymptomatic cases. These cases have been detected by school urinary screening test even though the total cases of MPGN show a decreasing trend. We have analyzed the clinical and pathological characteristics of children with MPGN according to the clinical manifestations at the time of disease presentation. Methods: A total of 18 patients who had been diagnosed with idiopathic MPGN by percutaneous renal biopsy from January 1990 to February 2004 were involved in our study. The patients were divided into 2 groups as the school urinary screening(A) group and the symptomatic(S) group according to the clinical manifestations at the time of disease presentation. Results: Out of the total 18 patients, 8(44.4%) were in the S group and 10(55.6%) were in the A group. The mean serum total protein, albumin and $C_3$ levels in the S group were significantly lower than those levels of the A group, respectively($4.9{\pm}1.2\;g/dL,\;vs\;7.0{\pm}0.5\;g/dL\;P=0.002,\;2.8{\pm}0.9\;g/dL\;vs.\;4.1{\pm}0.3\;g/dL\;P=0.002,\;63.9{\pm}36.4\;mg/dL\;vs.\;100.8{\pm}39.5\;g/dL\;P=0.041$). The mean total protein amount of 24 hour collected urine in the S group were significantly higher than that of the A group($3684.0{\pm}2601.3\;mg/m^2\;vs.\;559.4{\pm}4.6.9\;mg/m^2$, respectively, P=0.001). Hypocomplementemia was observed in 11(61.1%) out of 18 patients at the time of disease onset, 7(87.5%) in the S group and 4(40%) in the A group. However the hypocomplementemia was decreased in 6(33.3%) out of 18 patients at the time of final follow-up, 3(37.5%) in the S group and 3(30%) in the A group. According to the pathologic type, hypocomplementemia was observed 8 patients(61.5%) with type I disease, 1 patients (100%) with type II disease, 2 patients(50%) in type III disease at the disease onset, but 4 patients(30.8%) in type I disease, 1 patient(100%) in type II disease, 1 patient(33.3%) with type III disease at the time of last follow-up. The incidence of cellular crescent formation and tubular atropy. as observed on light microscopy, were higher in the S group compared to the A group. Mean grade of capillary wall thickening and, mesangial proliferation were significantly higher in the S group. Conclusion: MPGN, as diagnosed in patients with only asymptomatic urinary abnormalities, has been increasing, it is more frequent in asymptomatic patients than in patients with presenting symptoms. Our result suggests that MPGN should be considered in the renal biopsy diagnosis regardless of serum $C_3$ level when urinary abnormalities are found by school urinary screening test.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.5
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• pp.263-270
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• 2006

Purpose: Several radioisotope-labeled thymidine derivatives such as $[^{11}C]$thymidine was developed to demonstrate cell proliferation in tumor. But it is difficult to track metabolism with $[^{11}C]$thymidine due to rapid in vivo degradation and its short physical half-life. 3'-$[^{18}F]$fluoro-3'-deoxythymidine ($[^{18}F]$FLT) was reported to have the longer half life of fluorine-18 and the lack of metabolic degradation in vivo. Here, we described the synthesis of the 3'-$[^{18}F]$fluoro-3'-deoxythymidine ($[^{18}F]$FLT) and compared with $([^{18}F]FET)\;and\;([^{18}F]FDG)$ in cultured 9L cell and obtained the biodistribution and PET image in 9L tumor hearing rats. Material and Methods: For the synthesis of $[^{18}F]$FLT, 3-N-tert-butoxycarbonyl-(5'-O-(4,4'-dimet hoxytriphenylmethyl)-2'-deoxy-3'-O-(4-nitrobenzenesulfonyl)-${\beta}$-D-threopentofuranosyl)thymine was used as a FLT precursor, on which the tert-butyloxycarbonyl group was introduced to protect N3-position and nitrobenzenesulfonyl group. Radiolabeling of nosyl substitued precursor with $^{18}F$ was performed in acetonitrile at $120^{\circ}C$ and deproteced with 0.5 N HCI. The cell uptake was measured in cultured 9L glioma cell. The biodistribution was evaluated in 9L tumor bearing rats after intravenous injection at 10 min, 30 min, 60 min and 120 min and obtained PET image 60 minutes after injection. Results: The radiochemical yield was about 20-30% and radiochemical purity was more than 95% after HPLC purification. Cellular uptake of $[^{18}F]$FLT was increased as time elapsed. At 120 min post-injection, the ratios of tumor/blood, tumor/muscle and tumor/brain were $1.61{\pm}0.34,\;1.70{\pm}0.30\;and\;9.33{\pm}2.22$, respectively. The 9L tumor was well visualized at 60 min post injection in PET image. Conclusion: The uptake of $[^{18}F]$FLT in tumor was higher than in normal brain and PET image of $[^{18}F]$FLT was acceptable. These results suggest the possibility of $[^{18}F]$FLT at an imaging agent for brain tumor.