• 제목/요약/키워드: Gene silencing

검색결과 267건 처리시간 0.03초

Ectopic Overexpression of COTE1 Promotes Cellular Invasion of Hepatocellular Carcinoma

  • Zhang, Hai;Huang, Chang-Jun;Tian, Yuan;Wang, Yu-Ping;Han, Ze-Guang;Li, Xiang-Cheng
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권11호
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    • pp.5799-5804
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    • 2012
  • Family with sequence similarity 189, member B (FAM189B), alias COTE1, a putative oncogene selected by microarray, for the first time was here found to be significantly up-regulated in hepatocellular carcinoma (HCC) specimens and HCC cell lines. mRNA expression of COTE1 in HCC samples and cell lines was detected by reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR, while protein expression of COTE1 in HCC tissues was assessed by immunohistochemistry. In addition, invasion of HCC cells was observed after overexpressing or silencing COTE1. In the total of 48 paired HCC specimens, compared with the adjacent non-cancer tissues, the expression of COTE1 was up-regulated in 31 (p<0.01). In HCC cell lines, COTE1 expression was significantly higher than in normal human adult liver (p<0.01). Overexpression of COTE1 enhanced HCC-derived LM6 and MHCC-L cellular invasion in vitro. In contrast, COTE1 knockdown via RNAi markedly suppressed these phenotypes, as documented in LM3 and MHCC-H HCC cells. Mechanistic analyses indicated that COTE1 could physically associate with WW domain oxidoreductase (WWOX), a tumor suppressor. COTE1 may be closely correlated with invasion of hepatocellular carcinoma (HCC) cells and thus may serve as an effective target for gene therapy.

Silencing of Twist Expression by RNA Interference Suppresses Epithelial-mesenchymal Transition, Invasion, and Metastasis of Ovarian Cancer

  • Wang, Wen-Shuang;Yang, Xing-Sheng;Xia, Min;Jiang, Hai-Yang;Hou, Jian-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권9호
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    • pp.4435-4439
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    • 2012
  • Purpose: This study aimed to explore the role of the Twist gene in the epithelial-mesenchymal transition of ovarian cancer. Methods: An RNA interference plasmid expressing a small interfering RNA (siRNA)-targeting Twist (Twist siRNA vector) was designed, constructed, and transfected into the human ovarian cancer cell line A2780. Transfection efficiency was assessed under a fluorescence microscope. Changes in the expression of Twist mRNA in A2780 after transfection with the pGenesil Twist shRNA plasmid were analyzed through RT-PCR. MTT assays and adhesion experiments were applied to determine changes in proliferation and adhesion ability of A2870 after transfection with the Twist shRNA plasmid. Changes in the expression of the E-cadherin and N-cadherin proteins in A2780 after transfection with the Twist shRNA plasmid were analyzed using Western blotting. Result: The restructuring plasmid pGenesil-Twist shRNA was constructed successfully. After 48 h of culture, 80% of the cells expressed high-intensity GFP fluorescence and stability. The expression of Twist decreased significantly after the transfection of the Twist shRNA plasmid (P<0.05). Proliferation of the transfected Twist shRNA cells showed no difference with that of the A2780-nontransfection or A2780-si-control groups (P>0.05) but the adhesion ability of A2780 decreased dramatically (P<0.05). Expression of the E-cadherin protein increased, whereas that of the N-cadherin protein decreased compared with that in the A2780-nontransfection or A2780-si-control groups (P<0.05). Conclusion: Twist is essential for epithelial-mesenchymal transition, invasion, and metastasis of ovarian cancer.

Identification and Expression of Equine MER-Derived miRNAs

  • Gim, Jeong-An;Kim, Heui-Soo
    • Molecules and Cells
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    • 제40권4호
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    • pp.262-270
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    • 2017
  • MicroRNAs (miRNAs) are single-stranded, small RNAs (21-23 nucleotides) that function in gene silencing and translational inhibition via the RNA interference mechanism. Most miRNAs originate from host genomic regions, such as intergenic regions, introns, exons, and transposable elements (TEs). Here, we focused on the palindromic structure of medium reiteration frequencies (MERs), which are similar to precursor miRNAs. Five MER consensus sequences (MER5A1, MER53, MER81, MER91C, and MER117) were matched with paralogous transcripts predicted to be precursor miRNAs in the horse genome (equCab2) and located in either intergenic regions or introns. The MER5A1, MER53, and MER91C sequences obtained from RepeatMasker were matched with the eca-miR-544b, eca-miR-1302, and eca-miR-652 precursor sequences derived from Ensembl transcript database, respectively. Each precursor form was anticipated to yield two mature forms, and we confirmed miRNA expression in six different tissues (cerebrum, cerebellum, lung, spleen, adrenal gland, and duodenum) of one thoroughbred horse. MER5A1-derived miRNAs generally showed significantly higher expression in the lung than in other tissues. MER91C-derived miRNA-5p also showed significantly higher expression in the duodenum than in other tissues (cerebellum, lung, spleen, and adrenal gland). The MER117-overlapped expressed sequence tag generated polycistronic miRNAs, which showed higher expression in the duodenum than other tissues. These data indicate that horse MER transposons encode miRNAs that are expressed in several tissues and are thought to have biological functions.

Suppression of MED19 expression by shRNA induces inhibition of cell proliferation and tumorigenesis in human prostate cancer cells

  • Cui, Xingang;Xu, Danfeng;Lv, Chao;Qu, Fajun;He, Jin;Chen, Ming;Liu, Yushan;Gao, Yi;Che, Jianping;Yao, Yacheng;Yu, Hongyu
    • BMB Reports
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    • 제44권8호
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    • pp.547-552
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    • 2011
  • MED19 is a member of the Mediator that plays a key role in the activation and repression of signal transduction or the regulation of transcription in carcinomas. To tested the functional role of MED19 in human prostate cancer, we downregulated MED19 expression in prostate cancer cells (PC-3 and DU145) by lentivirus-mediated short hairpin (shRNA), and analyzed the effect of inhibition of MED19 on prostate cancer cell proliferation and tumorigenesis. The in vitro prostate cancer cell proliferation, colony formation, and in vivo tumor growth in nude mice xenografts was significantly reduced after the downregulation of MED19. Knockdown of MED19 caused S-phase arrest and induced apoptosis via modulation of Bid and Caspase 7. It was suggested that MED19 serves as a novel proliferation regulator that promotes growth of prostate cancer cells.

Identification of small molecules that inhibit the histone chaperone Asf1 and its chromatin function

  • Seol, Ja-Hwan;Song, Tae-Yang;Oh, Se Eun;Jo, Chanhee;Choi, Ahreum;Kim, Byungho;Park, Jinyoung;Hong, Suji;Song, Ilrang;Jung, Kwan Young;Yang, Jae-Hyun;Park, Hwangseo;Ahn, Jin-Hyun;Han, Jeung-Whan;Cho, Eun-Jung
    • BMB Reports
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    • 제48권12호
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    • pp.685-690
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    • 2015
  • The eukaryotic genome is packed into chromatin, which is important for the genomic integrity and gene regulation. Chromatin structures are maintained through assembly and disassembly of nucleosomes catalyzed by histone chaperones. Asf1 (anti-silencing function 1) is a highly conserved histone chaperone that mediates histone transfer on/off DNA and promotes histone H3 lysine 56 acetylation at globular core domain of histone H3. To elucidate the role of Asf1 in the modulation of chromatin structure, we screened and identified small molecules that inhibit Asf1 and H3K56 acetylation without affecting other histone modifications. These pyrimidine-2,4,6-trione derivative molecules inhibited the nucleosome assembly mediated by Asf1 in vitro, and reduced the H3K56 acetylation in HeLa cells. Furthermore, production of HSV viral particles was reduced by these compounds. As Asf1 is implicated in genome integrity, cell proliferation, and cancer, current Asf1 inhibitor molecules may offer an opportunity for the therapeutic development for treatment of diseases.

Inhibition of Herpesvirus-6B RNA Replication by Short Interference RNAs

  • Yoon, Jong-Sub;Kim, Sun-Hwa;Shin, Min-Chul;Lee, Dong-Gun;Hong, Seong-Karp;Jung, Yong-Tae;Khang, In-Gu;Shin, Wan-Shik;Kim, Chun-Choo;Paik, Soon-Young
    • BMB Reports
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    • 제37권3호
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    • pp.383-385
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    • 2004
  • RNA interference (RNAi) is a process of sequence-specific gene silencing, which is initiated by double-stranded RNA (dsRNA). RNAi may also serve as an antiviral system in vertebrates. This study describes the inhibition of herpesvirus-6B (HHV-6B) replication by short interference RNAs (siRNAs) that are targeted to the U38 sequence that encodes DNA polymerase. When virus-infected SupT1 cells were treated by siRNA, these cells blocked the cytopathic effect (CPE) and detected the HHV-6B antibody-negative in indirect immunofluorescence assays (IFA). Our result suggests that RNAi can efficiently block Herpesvirus-6B replication.

Structure and Function of NtCDPK1, a Calcium-dependent Protein Kinase in Tobccco

  • Yoon, Gyeong-Mee;Lee, Sang-Sook;Pai, Hyun-Sook
    • Journal of Plant Biotechnology
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    • 제2권2호
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    • pp.79-82
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    • 2000
  • We have isolated a cDNA encoding a calcium-dependent protein kinase (CDPK) in Nicotiana tabacum, which was designated NtCDPK1. Accumulation of the NtCDPK1 mRNA was stimulated by various stimuli, including phytohormones, CaCl$_2$ wounding, fungal elicitors, chitin and methyl jasmonate. The NtCDPK1 gene encodes a functional Ser/Thr protein kinase of which phosphorylation activity is strongly induced by calcium. By analyzing expression of the NtCDPK1-GFP fusion protein and by immunoblotting with antibody which reacts with NtCDPK1, we found that NtCDPK1 is localized in membrane and nucleus in plant cells. Silencing expression of the NtCDPK1 transgene resulted in marked decrease of lateral root development in the transgenic tobacco plants. Yeast two hybrid screening using NtCDPK1 as a bait identified a tobacco homologue of proteasome regulatory subunit 21D7, designated Nt21D7. The 21D7 mRNA has been shown to be predominantly expressed in proliferating tissues in the cell cycledependent manner in carrot. The recombinant NtCDPK1 protein associated with Nt21D7 in vitro, and could phosphorylate the Nt21D7 protein in vitro in the presence of calcium, suggesting that Nt21D7 protein is a natural substrate of NtCDPK1 in tobacco. These results suggest that NtCDPK1 may regulate tell proliferation processes, such as lateral root formation, by regulating specificity and/or activity of proteasome-mediated protein degradation pathway.

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VEGF siRNA Delivery by a Cancer-Specific Cell-Penetrating Peptide

  • Lee, Young Woong;Hwang, Young Eun;Lee, Ju Young;Sohn, Jung-Hoon;Sung, Bong Hyun;Kim, Sun Chang
    • Journal of Microbiology and Biotechnology
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    • 제28권3호
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    • pp.367-374
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    • 2018
  • RNA interference provides an effective tool for developing antitumor therapies. Cell-penetrating peptides (CPPs) are delivery vectors widely used to efficiently transport small-interfering RNA (siRNA) to intracellular targets. In this study, we investigated the efficacy of the cancer-specific CPP carrier BR2 to specifically transport siRNA to cancer-target cells. Our results showed that BR2 formed a complex with anti-vascular endothelial growth factor siRNA (siVEGF) that exhibited the appropriate size and surface charge for in vivo treatment. Additionally, the BR2-VEGF siRNA complex exhibited significant serum stability and high levels of gene-silencing effects in vitro. Moreover, the transfection efficiency of the complex into a cancer cell line was higher than that observed in non-cancer cell lines, resulting in downregulated intracellular VEGF levels in HeLa cells and comprehensively improved antitumor efficacy in the absence of significant toxicity. These results indicated that BR2 has significant potential for the safe, efficient, and specific delivery of siRNA for diverse applications.

Sinapic acid induces the expression of thermogenic signature genes and lipolysis through activation of PKA/CREB signaling in brown adipocytes

  • Hossain, Monir;Imran, Khan Mohammad;Rahman, Md. Shamim;Yoon, Dahyeon;Marimuthu, Vignesh;Kim, Yong-Sik
    • BMB Reports
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    • 제53권3호
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    • pp.142-147
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    • 2020
  • Lipid accumulation in white adipose tissue is the key contributor to the obesity and orchestrates numerous metabolic health problems such as type 2 diabetes, hypertension, atherosclerosis, and cancer. Nonetheless, the prevention and treatment of obesity are still inadequate. Recently, scientists found that brown adipose tissue (BAT) in adult humans has functions that are diametrically opposite to those of white adipose tissue and that BAT holds promise for a new strategy to counteract obesity. In this study, we evaluated the potential of sinapic acid (SA) to promote the thermogenic program and lipolysis in BAT. SA treatment of brown adipocytes induced the expression of brown-adipocyte activation-related genes such as Ucp1, Pgc-1α, and Prdm16. Furthermore, structural analysis and western blot revealed that SA upregulates protein kinase A (PKA) phosphorylation with competitive inhibition by a pan-PKA inhibitor, H89. SA binds to the adenosine triphosphate (ATP) site on the PKA catalytic subunit where H89 binds specifically. PKA-cat-α1 gene-silencing experiments confirmed that SA activates the thermogenic program via a mechanism involving PKA and cyclic AMP response element-binding protein (CREB) signaling. Moreover, SA treatment promoted lipolysis via a PKA/p38-mediated pathway. Our findings may allow us to open a new avenue of strategies against obesity and need further investigation.

Down-regulation of EZH2 by RNA Interference Inhibits Proliferation and Invasion of ACHN Cells via the Wnt/β-catenin Pathway

  • Yuan, Jun-Bin;Yang, Luo-Yan;Tang, Zheng-Yan;Zu, Xiong-Bing;Qi, Lin
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권12호
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    • pp.6197-6201
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    • 2012
  • Although enhancer of zeste homolog 2 (EZH2) has been reported as an independent prognostic factor in renal cell carcinoma (RCC), little is known about the exact mechanism of EZH2 in promoting the genesis of RCC. However, several studies have shown that dysregulation of the Wnt/${\beta}$-catenin signaling pathway plays a crucial role. Therefore, we determined whether EZH2 could affect ACHN human RCC cell proliferation and invasion via the Wnt/${\beta}$-catenin pathway. In the present study, we investigated the effects of short interfering RNA (siRNA)-mediated EZH2 gene silencing on Wnt/${\beta}$-catenin signaling in ACHN cells. EZH2-siRNA markedly inhibited the proliferation and invasion capabilities of ACHN, while also reducing the expression of EZH2, Wnt3a and ${\beta}$-catenin. In contrast, cellular expression of GSK-$3{\beta}$ (glycogen synthase kinase-$3{\beta}$), an inhibitor of the Wnt/${\beta}$-catenin pathway, was conspicuously higher after transfection of EZH2 siRNA. These preliminary findings suggest EZH2 may promote proliferation and invasion of ACHN cells via action on the Wnt/${\beta}$-catenin signaling pathway.