• Title/Summary/Keyword: inhibitory mechanism

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FNC, a Novel Nucleoside Analogue, Blocks Invasion of Aggressive Non-Hodgkin Lymphoma Cell Lines Via Inhibition of the Wnt/β-Catenin Signaling Pathway

  • Zhang, Yan;Wang, Chen-Ping;Ding, Xi-Xi;Wang, Ning;Ma, Fang;Jiang, Jin-Hua;Wang, Qing-Duan;Chang, Jun-Biao
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6829-6835
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    • 2014
  • Chemotherapy is the primary therapy for malignant lymphoma (ML). However, the clinical outcome is still far from satisfactory. Consequently, an understanding of the mechanism of modulating cancer cell invasion, migration and metastasis is important for the development of more effective chemotherapeutic agents. FNC, 2'-deoxy-2'-${\beta}$-fluoro-4'-azidocytidine, a novel cytidine analogue, has demonstrated significantly inhibitory effects on proliferation of several non-Hodgkin lymphoma (NHL) cell lines. A previous study indicated that FNC effectively inhibited the growth of Raji and JeKo-1 cells in dose-time dependent effects with $IC_{50}$ values of $0.2{\mu}M$ and $0.097{\mu}M$, respectively. This study was focused on investigating the anti-invasive properties of FNC on NHL cells and its potential mechanisms of action. Cell adhesion and transwell chamber assays were utilized to investigate the anti-invasive effects of FNC on Raji and JeKo-1 cells. Real-time PCR and Western blotting were employed to qualify the expression of ${\beta}$-catenin, the glycogen synthase kinase-3 beta (GSK-$3{\beta}$), E-cadherin vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). The results revealed that FNC remarkably inhibited the adhesion, migration and invasion of two human aggressive non-Hodgkin lymphoma cell lines in a dose dependent manner. Furthermore, ${\beta}$-catenin, MMP-2, MMP-9, VEGF mRNA and protein levels were decreased after FNC treatment, while GSK-$3{\beta}$ and E-cadherin increased. Our studies thus provide evidence and a rationale that FNC may offer an effective chemotherapeutic agent by regulating the invasion and metastasis of aggressive non-Hodgkin lymphoma via inhibition of the Wnt/${\beta}$-catenin signaling pathway.

Scutellaria Extract Decreases the Proportion of Side Population Cells in a Myeloma Cell Line by Down-regulating the Expression of ABCG2 Protein

  • Lin, Mei-Gui;Liu, Li-Ping;Li, Chen-Yin;Zhang, Meng;Chen, Yuling;Qin, Jian;Gu, Yue-Yu;Li, Zhi;Wu, Xin-Lin;Mo, Sui-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7179-7186
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    • 2013
  • Background and Aims: Scutellaria is one of the most popular traditional Chinese herbal remedies against various human diseases, including cancer. In this study, we examined the active effects of Scutellaria extract and its main flavonoid constituents on the proportion of side population cells within human multiple myeloma cell line RPMI8226 in vitro and explored the potential molecular mechanisms involved. Materials and Methods: The contents of flavonoids in ethanolic extract of Scutellaria baicalensis Georgi were determined using high performance liquid chromatography. The antiproliferative effect of the ethanolic extract on RPMI-8226 was determined by CCK assay. Apoptosis was measured by annexin combining with propidium iodide in a flow cytometer. Cell cycle analysis was performed by propidium iodide staining in combination with flow cytometry analysis. Hoechst 33342 exclusion assay was used for the identification of side population within RPMI8226 cells. The expression of ABCG2 protein was assessed by Western blotting assay. Results: The content of major flavonoids constitutents of Scutellaria extract was baicalin (10.2%), wogonoside (2.50%), baicalein (2.29%), and wogonin (0.99%), respectively. The crude Scutellaria extract did not show significant anti-proliferative effect, apoptosis induction and cell cycle arrest in RPMI-8226 within the concentrations of $1-75{\mu}g/mL$. However, the ethanolic extract, baicalein, wogonin and baicalin reduced the side population cells in RPMI-8226, and data showed that baicalein and wogonin had stronger inhibitory effects. Correspondingly, they also exhibited significant effects on decreasing the expression level of ABCG2 protein in RPMI-8226 in vitro. Conclusions: Our results for the first time demonstrated a novel mechanism of action for Scutellaria extract and its main active flavonoids, namely targeting SP cells by modulating the expression of ABCG2 protein. This study provides an insight for new therapeutic strategies targeting cancer stem cells of multiple myeloma.

PKA-Mediated Regulation of B/K Gene Transcription in PC12 Cells

  • Choi, Mi-Hyun;Kim, Ho-Shik;Choi, Sung-Ho;Kim, Mi-Young;Jang, Yoon-Seong;Jang, Young-Min;Lee, Jeong-Hwa;Jeong, Seong-Whan;Kim, In-Kyung;Kwon, Oh-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.6
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    • pp.333-339
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    • 2005
  • B/K protein is a novel protein containing double C2-like domains. We examined the specific signaling pathway that regulates the transcription of B/K in PC12 cells. When the cells were treated with forskolin ($50{\mu}M$), B/K mRNA and protein levels were time-dependently decreased, reaching the lowest level at 3 or 4 hr, and thereafter returning to the control level. Chemicals such as dibutyryl-cAMP, cellpermeable cyclic AMP (cAMP) analogue and CGS21680, adenosine receptor $A_{2A}$ agonist, also repressed the B/K transcription. However, 1,9-dideoxyforskolin did not show inhibitory effect on B/K transcription, suggesting direct involvement of cAMP in the forskolin-induced inhibition of B/K transcription. Effect of forskolin, dibutyryl cAMP and CGS21680 was significantly reduced in PKA-deficient PC12 cell line (PC12-123.7). One cAMP-response element (CRE)-like sequence (B/K CLS) was found in the promoter region of B/K DNA, and electrophoretic mobility shift assay indicated its binding to CREM and CREB. Forskolin significantly suppressed the promoter activity in CHO-K1 cells transfected with the constructs containing B/K CLS, but not with the construct in which B/K CLS was mutated (AC:TG). Taken together, we suggest that the transcription of B/K gene in PC12 cells may be regulated by PKA-dependent mechanism.

Antibacterial activity of Callophyllis japonica-methanol extracts against the pathogenic bacteria from swine (볏붉은잎 추출물의 돼지 유래 병원성 세균에 대한 항균효과)

  • Jeong, Jin-Woo;Jeong, Chan-Woo;Kim, Jeong-Tae;Yang, Won-Joon;Ahn, Mee-Jung;Kim, Byeoung-Hak;Kim, Joo-Ah;Shin, Tae-Kyun
    • Korean Journal of Veterinary Service
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    • v.32 no.4
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    • pp.353-359
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    • 2009
  • Interest in marine organisms as potential sources of bioactive agents has increased in recent years. The red seaweed, Callophyllis (C.) japonica, is abundant in the coastal regions of Jeju Island in South Korea. A previous study shows that C. japonica extracts have antioxidant activity and radioprotective effects. In this study, an methanol extract of C. japonica was tested whether it has antibacterial effects against the bacteria from swine. In vitro antibacterial activities of the crude extracts prepared from the C. japonica using 80 % methanol were tested for inhibitory activity against the Escherichia (E.) coli (S175), Enterococcus (E.) faecium (ATCC 51558), Salmonella (S.) Typhimurium and Staphylo-coccus (S.) aureus (ATCC 25923) by using broth dilution method. All organisms were incubated in brain heart infusion medium containing 1% extract at 0, 4, 8, 12 and 24 hrs. The 3 days-old piglets were fed an experimental diet supplemented with 1% C. japonica for 1 week. And the change of the coliform bacteria in feces were examined after supplement of C. japonica for 1 week. When the inocula containing $10^2{\sim}10^3$CFU/ml of each organism were used the extracts of C. japonica showed various degrees of antibacterial effects on all bacteria tested. The CFU value ($6.3\times10^8$CFU/ml) of C. japonica for E. coli was decreased 30% compared with vehicle controls ($9.0\times10^8$CFU/ml) after 8 hrs incubation. The proliferation rate of E. faecium was inhibited about 68% at 4 hrs, 81% at 8 hrs and 76% at 12 hrs after incubation, respectively. The proliferation rate of S. Typhimurium was inhibited about 96% at 4 hrs, 90% at 8 hrs and 72% at 12 hrs after incubation with extracts of C. japonica. The proliferation rate of S. aureus was inhibited more than 90% each time courses. Conclusively, a red seaweed extract of C. japonica was found to be effective against a number of gram negative and gram positive bacteria such as E. coli, E. faecium, S. Typhimurium, and S. aureus. The number of coliform bacteria was increased in the 1% C. japonica-treated group, as compared to those of controls. This result suggests that C. japonica extracts be added as an effective natural antibacterial agent. The precise mechanism of antibacterial effects and its application on swine industry remains to be further studied.

Effects of Primisulfuron and Imazethapyr Treated with Piperonyl Butoxide on Growth and Acetolactate Synthase Activity in Several Corn Cultivars (Primisulfuron, Imazethapyr와 Piperonyl Butoxide의 혼합처리(混合處理)가 옥수수의 생장(生長) 및 ALS산소(酸素) 활성(活性)에 미치는 영향(影響))

  • Piao, R.Z.;Pyon, J.Y.
    • Korean Journal of Weed Science
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    • v.18 no.4
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    • pp.333-340
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    • 1998
  • The combined effects of primisulfuron and imazethapyr treated with piperonyl butoxide(PBO) on growth inhibition and acetolactate synthase(ALS) activity in corn were studied to identify the tolerance mechanism among corn cultivars. Pioneer 3751 IR showed resistance to primisulfuron and imazethapyr, but Pioneer 3751 and Chalok 2 were susceptible to them. Pioneer 3751 IR was tolerant to primisulfuron regardless of PBO treatment, but Pioneer 3751, Suwon 118 and Chalok 2 were more greatly inhibited by combined treatment of primisulfuron with PBO. Synergistic effect on growth inhibition in Pioneer 3751 IR, Pioneer 3751, Suwon 118 and Chalok 2 was not occurred when imazethapyr was treated with PBO, but Pioneer 3751, Suwon 118 and Chalok 2 tended to inhibit by combined treatment of imazethapyr with PBO. Pioneer 3751 IR showed higher ALS activity than Pioneer 3751 when primisulfuron or imazethapyr was treated. ALS activity was inhibited by primisulfuron at $0.01{\mu}M$ or above and imazethapyr at $1{\mu}M$ or above, and inhibitory effect on ALS activity was observed by primisufuron and imazethapyr treatments with PBO.

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Selective Mechanism of Oxvfluorfen and Chlormethoxynil in Crops and Weed Species (Oxyfluorfen과 Chlormethoxynil의 선택작용성(選擇作用性))

  • Lee, J.H.;Pyon, J.Y.;Lee, J.Y.
    • Korean Journal of Weed Science
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    • v.14 no.4
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    • pp.280-290
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    • 1994
  • The germination and the nutrient culture tests in the growth chamber and pot experiment under two types of soil conditions were conducted to determine the selectivity of oxyfluorfen and chlormethoxynil in crops and weeds and for characterization of selective mode of action, the absorption study was also conducted with different absorption methods and application time using $^{14}C$-oxyfluorfen. Oxyfluorfen showed more growth inhibitory effects than chlormethoxynil. In the nutrient culture test, rice growth was greatly inhibited at 2-leaf stage than at 4-leaf stage, and the shoot parts were more inhibited than the root parts. By preemergence application of both herbicides, higher growth inhibition was observed in sandy loam soil than in clay loam soil. Absorption and translocation of $^{14}C$-oxyfluorfen were higher by foliar application than by root treatment, and selectivity of crops and weed species may be explained partly by the amount of absorption.

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Induction of Apoptosis by Sageretia thea Branch Extracts through Activation of NF-κB Signaling Pathway in Human Colorectal Cancer Cells (상동나무(Sageretia thea) 가지추출물의 대장암세포에서 NF-κB 신호전달 활성화를 통한 세포사멸 유도활성)

  • Kim, Jeong Dong;Park, Su Bin;Eo, Hyun Ji;Park, Gwang Hun;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.33 no.5
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    • pp.428-435
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    • 2020
  • In this study, we evaluated the inhibitory effect against cell growth and potential molecular mechanism of 100% ethanol extracts of branch from Sageretia thea in human colorectal cancer cells, HCT116. Ethanol dose-dependently extracts of STB significantly suppressed the growth of HCT116 cells through apoptosis. STB activated NF-κB signaling pathway through IκB-α proteasomal degradation and inducing p65 accumulation in nucleus. The inhibition of GSK3β by LiCl didn't affect STB mediated degradation IκB-α but STB mediated p65 accumulation in nucleus. In addition, STB phosphorylated GSK3β. Based on these findings, STB may be a potential candidate for the development of anti-cancer agents for human colorectal cancer.

Inhibitory Effects of Flavonoids on Growth of HT-29 Human Colon Cancer Cells (Flavonoid의 HT-29 대장암세포 증식 억제 효과)

  • Cho, Young;Choi, Mi-Yong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.3
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    • pp.338-346
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    • 2015
  • This study was performed to elucidate the anti-proliferative and apoptotic mechanism of flavonoids in HT-29 human colon cancer cells. We investigated the anti-proliferative activity of flavonoids in HT-29 human colon cancer cells via cell viability assay (MTT assay), caspase-3 activity, RT-PCR, and western blotting. We cultured HT-29 cells in the presence of various flavonoids (apigenin, rutin, naringenin, and myricetin) at a concentration of $100{\mu}M$. In the MTT assay, naringenin showed the strongest effect on cell viability in HT-29 colon cancer cells. Caspase-3 activity, a marker of apoptosis, significantly increased upon naringenin treatment. For RT-PCR, myricetin significantly increased Bax protein levels, naringenin increased p53 protein levels, and rutin reduced expression of the anti-apoptotic protein Bcl-2. Western blotting of HT-29 colon cancer cells showed that myricetin increased cleaved caspase-3 protein levels, naringenin significantly increased poly (ADP-ribose) polymerase protein levels, and rutin increased E-cadherin protein levels. These results indicate that flavonoid exerts anticancer effects on human colon HT-29 cells through a caspase-dependent apoptotic pathway.

ANTIBACTERIAL EFFECT OF POLYPHOSPHATES ON MUTANS STREPTOCOCCI (Mutans streptococci에 대한 polyphosphate의 항균효과)

  • Kang, Kye-Sook;Choi, Yeong-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.1
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    • pp.80-91
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    • 2003
  • Mutans streptococci, especially S. mutans and S. sobrinus strongly implicated in pathogenesis of dental caries, the major cause of tooth loss in children. Use of an antibacterial agent controlling dental caries has been rationalized. The present study was performed to observe the antibacterial effect of inorganic polyphosphates (polyP) on S. mutans and S. sobrinus. S. mutans GS5 and S. sobrinus 6715 were grown in brain-heart infusion broth with or without polyP. Minimal inhibitory concentration (MIC) of polyP for S. mutans GS5 was determined to be 0.08% and that for S. sobrius 6715 was 0.17%. PolyP 15 added to the growing culture of S. mutans GS5 and S. sobrinus 6715 at their exponential phase was as effective in inhibiting the growth of S. mutans GS5 and S. sobrinus 6715 as polyP added at the very beginning of the culture. More than 85% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. mutans GS5 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. And more than 99.9% of the cells lost their viability determined by viable cell count when polyP 15 was added to the culture of growing S. sobrinus 6715 at MIC, suggesting that polyP 15 has bacterial effect on the bacterium. Intracellular nucleotide release from S. mutans CS5 and S. sobrinus 6715 was increased in the presence of polyP 15 for 5h but was not really reversed by the addition of divalent cations like $Ca^{++}\;and\;Mg^{++}$. The majority of the cells appeared to be atypical in their shape, demonstrating accumulation of highly electron-dense granules and ghost cells. The overall results suggest that polyP have a strong bactericidal activity against S. mutans and S. sobrinus in which lysis in relation to chelation may not play the major role but unknown mechanism that possibly affects the viability of the bacterium may be involved. PolyP may be used as an agent for prevention of dental caries.

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Inhibition of pRB Phosphorylation and Induction of p21WAF1/CIP1 Occur During cAMP-induced Growth Arrest in Human Neuroblastoma Cells (인체 신경아세포종에서 cAMP 처리에 의한 pRB의 인산화 억제 및 p21WAF1/CIP1의 유도)

  • Park, Yung-Hyun;Lee, Sang-Hyeon
    • Journal of Life Science
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    • v.13 no.5
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    • pp.642-650
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    • 2003
  • To develop a new approach to the treatment of neuroblastoma cells we evaluated the effect of cAMP on the Ewing's sarcoma cell line CHP-100. We observed that the proliferation-inhibitory effect of cAMP analogs was due to cell cycle arrest and induction of apoptosis, which was confirmed by observing the morphological changes and DNA fragmentation. DNA flow cytometric analysis revealed that cAMP arrested the cell cycle progression at the G1 phase, which effects were associated with inhibition of phosphorylation of retinoblastoma protein (pRB) and enhanced binding of pRB and the transcription factor E2F-1. cAMP also suppressed the cyclin-dependent kinase (Cdk) 2 and cyclin E-associated kinase activity without changes of their expressions. Furthermore, cAMP induced the levels of Cdk inhibitor $p21^{WAF1/CIP1$ expression and p21 proteins induced by cAMP were associated with Cdk2. Overall, our results identify a combined mechanism involving the inhibition of pRB phosphorylation and induction of p21 as targets for cAMP, and this may explain some of its anti-cancer effects.