• 제목/요약/키워드: knock-down

검색결과 131건 처리시간 0.029초

Studies on the Function of Peroxidasins in Innate Immune System in C. elegans

  • Cho, Jeong Hoon
    • 통합자연과학논문집
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    • 제12권4호
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    • pp.142-146
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    • 2019
  • Peroxidasin is a unique member of peroxidase family in that it has extracellular matrix (ECM) motif as well as peroxidase activity. Peroxidasins are involved in consolidation the extracellular matrix during development and in innate immune defense. C. elegans has two functional peroxidasins, PXN-1 and PXN-2, and PXN-2 is known to contribute to innate immune system. However, it is not clear of PXN-1 function in innate immune system. Therefore, this study is focused on the function of PXN-1 and the relationship between PXN-1 and PXN-2 in innate defense system in C. elegans. When pxn-1 was knocked down by RNAi, the worm turned to be more resistant to pathogens, Staphylococcus aureus and Pseudomonas aeruginosa and the enhanced resistance was abolished in pxn-1pxn-2 double knock down. By contrast, pxn-2 knock down showed stronger susceptibility to the pathogens. These results suggest that pxn-2 can contribute the pathogen resistance and pxn-1 can suppress the pathogen resistance. To confirm the idea, overexpression experiments were performed. Overexpression of pxn-1 showed more susceptible to pathogens compared to the control and double overexpression of pxn-1pxn-2 overcame the susceptibility of pxn-1 overexpression to the pathogens. On the other hand, pxn-2 overexpression made the worm more resistant to the pathogens and the resistance was maintained in pxn-1pxn-2 double overexpression. The comparison of the susceptibilities to the bacterial pathogens in above mentioned constructs suggests that PXN-1 suppress the function of PXN-2 in defense against bacterial pathogens in Caenorhabditis elegans.

Expression Analysis of Two Cancer-testis Genes, FBXO39 and TDRD4, in Breast Cancer Tissues and Cell Lines

  • Seifi-Alan, Mahnaz;Shamsi, Roshanak;Ghafouri-Fard, Soudeh;Mirfakhraie, Reza;Zare-Abdollahi, Davood;Movafagh, Abolfazl;Modarressi, Mohammad Hossein;Kazemi, Golnesa;Geranpayeh, Lobat;Najafi-Ashtiani, Mitra
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권11호
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    • pp.6625-6629
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    • 2013
  • Breast cancer accounts for one third of new cancer cases among women. The need for biomarkers for early detection is the stimulus to researchers to evaluate altered expression of genes in tumours. Cancer-testis (CT) genes are a group with limited expression in normal tissues except testis but up-regulation in a wide variety of cancers. We here evaluated expression of two CT genes named FBXO39 and TDRD4 in 32 invasive ductal carcinoma samples, 10 fibroadenomas and 6 normal breast tissue samples, in addition to two breast cancer cell lines, MCF-7 and MDA-MB-231, by the means of quantitative real time RT-PCR. FBXO39 showed significant up-regulation in invasive ductal carcinoma samples in comparison with normal samples. It also was expressed in both cell lines and after RHOXF1 gene knock down it was down-regulated in MCF-7 but up-regulated in the MDA-MB-231 cell line. TDRD4 was not expressed in the MCF-7 cell line and any of the tissue samples except testis. However, it was expressed in MDA-MB-231 and was up-regulated after RHOXF1 gene knock down. Our results show that FBXO39 but not TDRD4 can be used for cancer detection and if proved to be immunogenic, might be a putative candidate for breast cancer immunotherapy.

구강암편평세포암에서 c-Met 발현여부에 따른 (-)-Epigallocatechin-3-Gallate의 세포사멸 및 종양침습억제효과의 변화분석 (Analysis of (-)-Epigallocatechin-3-Gallate-Induced Apoptosis and Inhibition of Invasiveness in Oral Cavity Carcinoma Squamous Cell Carcinoma According to Expression of c-Met)

  • 신유섭;고윤우;최은창;강성운;황혜숙;추옥성;이한빈;김철호
    • 대한두경부종양학회지
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    • 제27권1호
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    • pp.3-11
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    • 2011
  • Hepatocyte growth factor(HGF) and c-Met play an important role in the control of tumor growth and invasion, and they are known to be good prognostic indicators of patient outcome. Epigallocatechin-3-gallate (EGCG) has been shown to have chemopreventive and therapeutic properties by modulating multiple signal pathways regarding the control of proliferation and invasion of cells. In this study, we evaluated the role of c-Met in EGCG-induced inhibition of invasion and apoptosis in an oral cancer cell line. In KB cells where c-Met was knocked down with siRNA, we performed invasion assay and FACS with Annexin V-FITC/PT staining. In addition, we checked the change of mitochondrial membrane potential(MMP) and the generation of reactive oxygen species(ROS). EGCG-induced inhibition of invasiveness was significantly decreased after the knock-down of c-Met. EGCG-induced apoptosis, MMP change and ROS generation was also reduced in c-Met knock-ed-down KB cells. These results suggest that c-Met is involved in EGCG-induced apoptosis and inhibition of invasiveness of oral cancer cell line.

Regulator of calcineurin 1-4과 파골세포 분화의 관련성 (Relationship between the Regulator of Calcineurin 1-4 Isoform and In Vitro Osteoclast Differentiation)

  • 박경록
    • 생명과학회지
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    • 제25권2호
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    • pp.223-230
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    • 2015
  • RCAN1은 calcineurin을 억제하는 내인성 단백질로 calcineurin-NFATc1 신호전달 경로와 관련된 질환의 병인에 중요한 역할을 담당한다. 특히 RCAN1-4 아형 유전자의 경우 NFATc1 전사인자에 의해 조절된다. RANKL 자극은 calcineurin-NFATc1 경로로 파골세포 분화를 유도하는데, RCAN1과 파골세포의 분화에 관련된 연구는 보고 된 바 없다. 따라서 본 연구는 RANKL 처리에 의해 파골세포 분화가 유도될 때 RCAN1이 calcineurin-NFATc1 경로에 미치는 영향을 in vitro에서 조사했다. 마우스로부터 분리한 골수단핵세포에 RANKL을 처리하여 파골세포 분화를 유도했다. RANKL 처리 후 조사 대상 유전자의 mRNA 발현과 단백질 발현을 각각 RT-PCR과 Western blot로써 측정했다. 마우스 RCAN1-4 vector를 파골전구세포인 RAW 264.7 단핵세포주와 골수단핵세포에 형질도입(transfection)시켜 RCAN1-4 유전자의 과발현을 유도했다. 형질도입 후 파골세포 분화의 형태적 변화는 TRAP 염색을 통해 관찰했다. RANKL 처리 후 NFATc1, calcineurin, RCAN1-4 mRNA 발현은 크게 증가했다. 단백질 발현의 경우 NFATc1과 RCAN1은 증가했으나 calcineurin은 대조군과 차이가 없었다. RCAN1-4 유전자의 과발현 유도 시 RCAN1-4 mRNA는 크게 증가되었으나 RCAN1 단백질 발현은 증가되지 않았다. 특히 RANKL 존재 시 RCAN1 유전자를 knock-down시켜도 RCAN1 발현은 정상적으로 유지되었다. 한편, NFATc1 발현은 과발현 유도시 감소했고 knock-down 유도 시 증가하는 경향을 보였다. RCAN1-4 유전자 과발현을 유도한 골수단핵세포에서 배양 5일 후 파골세포 분화는 대조군과 차이가 없었다. 이러한 결과는 RANKL에 의한 파골세포 분화 시 RCAN1이 calcineurin-NFATc1 경로를 통해 파골세포 분화에 미치는 영향은 제한적일 것으로 사료된다.

SETDB1 genomic DNA 를 표적하는 TALEN construct 제작 및 분석 (TALEN Constructs and Validation for Targeting of SETDB1 Genomic DNA)

  • 노희정;강윤성;김근철
    • 생명과학회지
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    • 제24권12호
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    • pp.1269-1275
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    • 2014
  • TALEN은 특정유전자를 표적 하여 knock-out 시킬 수 있는 새로운 개념의 유전자 클로닝 방법이다. TALEN 플라스미드에는 DNA binding 도메인과 Fok1 절단효소 기능이 융합되어 있기 때문에, genomic DNA 의 어느 부위라도 결합할 수 있고, 표적 염기서열을 절단하여 유전자 돌연변이를 유도할 수 있다. 본 연구에서 우리는 SETDB1 HMTase 유전자의 단백질 개시코돈 과 프로모터 -25 upstream 부위를 표적 하는 두 종의 TALEN constructs 를 제작하였다. 이를 위하여 두 단계의 클로닝이 진행되었다. 첫 번째는 모듈벡터에서 pFUS배열벡터로 표적서열을 옮겨 콜로니 PCR을 통해 smear밴드와 Esp1 제한 효소를 이용하여 약 1 kb의 insert가 들어 있음을 확인하였다. 두 번째는 배열 벡터로부터 TALEN 발현벡터로 옮기는 과정을 진행하였으며, 염기서열분석을 통해 확인하였다. 그 결과 최초의 고안된 모듈벡터 서열들이 약 100 bp 간격으로 배열되어 있음을 확인하였다. 제작된 TALEN-DBEX2 construct는 transfection을 통해 SETDB1의 발현이 사라지는 것을 확인하였고, T7E1 분석을 통하여 표적부위에서 돌연변이가 발생하였음을 추정할 수 있었다. 한편, TALEN-DBPR25 transfection을 통하여서도 SETDB1의 발현이 감소하는 현상을 확인 하였다. DBEX2, DBPR25를 이입시킨 HeLa 세포에서 세포 형태가 길어지는 현상을 관찰할 수 있었다. 그러므로 단백질 개시코돈 또는 -25 upstream을 표적 하는 TALEN knock-out 방법은 SETDB1 유전자의 기능연구에 매우 유용하다고 사료된다.

shRNA Mediated RHOXF1 Silencing Influences Expression of BCL2 but not CASP8 in MCF-7 and MDA-MB-231 Cell Lines

  • Ghafouri-Fard, Soudeh;Abdollahi, Davood Zare;Omrani, Mirdavood;Azizi, Faezeh
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권11호
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    • pp.5865-5869
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    • 2012
  • RHOXF1 has been shown to be expressed in embryonic stem cells, adult germline stem cells and some cancer lines. It has been proposed as a candidate gene to encode transcription factors regulating downstream genes in the human testis with antiapoptotic effects. Its expression in cancer cell lines has implied a similar role in the process of tumorigenesis. The human breast cancer cell lines MDA-MB-231 and MCF-7 were cultured in DMEM medium and transfected with a pGFP-V-RS plasmid bearing an RHOXF1 specific shRNA. Quantitative real-time RT-PCR was performed for RHOXF1, CASP8, BCL2 and HPRT genes. Decreased RHOXF1 expression was confirmed in cells after transfection. shRNA knock down of RHOXF1 resulted in significantly decreased BCL2 expression in both cell lines but no change in CASP8 expression. shRNA targeting RHOXF1 was shown to specifically mediate RHOXF1 gene silencing, so RHOXF1 can mediate transcriptional activation of the BCL2 in cancers and may render tumor cells resistant to apoptotic cell death induced by anticancer therapy. shRNA mediated knock down of RHOXF1 can be effective in induction of apoptotic pathway in cancer cells via BCL2 downregulation, so it can have potential therapeutic utility for human breast cancer.

The role of protein arginine-methyltransferase 1 in gliomagenesis

  • Wang, Shan;Tan, Xiaochao;Yang, Bin;Yin, Bin;Yuan, Jiangang;Qiang, Boqin;Peng, Xiaozhong
    • BMB Reports
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    • 제45권8호
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    • pp.470-475
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    • 2012
  • Protein arginine methyltransferase 1 (PRMT1), a type-I arginine methyltransferase, has been implicated in diverse cellular events. We have focused on the role of PRMT1 in gliomagenesis. In this study, we showed that PRMT1 expression was up-regulated in glioma tissues and cell lines compared with normal brain tissues. The knock-down of PRMT1 resulted in an arrest in the G1-S phase of the cell cycle, proliferation inhibition and apoptosis induction in four glioma cell lines (T98G, U87MG, U251, and A172). Moreover, an in vivo study confirmed that the tumor growth in nude mouse xenografts was significantly decreased in the RNAi-PRMT1 group. Additionally, we found that the level of the asymmetric dimethylated modification of H4R3, a substrate of PRMT1, was higher in glioma cells than in normal brain tissues and decreased after PRMT1 knock-down. Our data suggest a potential role for PRMT1 as a novel biomarker of and therapeutic target in gliomas.

TRPM7 Is Essential for RANKL-Induced Osteoclastogenesis

  • Yang, Yu-Mi;Jung, Hwi-Hoon;Lee, Sung Jun;Choi, Hyung-Jun;Kim, Min Seuk;Shin, Dong Min
    • The Korean Journal of Physiology and Pharmacology
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    • 제17권1호
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    • pp.65-71
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    • 2013
  • The transient receptor potential melastatin type 7 (TRPM7) channel is a widely expressed non-selective cation channel with fusion to the C-terminal alpha kinase domain and regarded as a key regulator of whole body $Mg^{2+}$ homeostasis in mammals. However, the roles of TRPM7 during osteoclastogenesis in RAW264.7 cells and bone marrow-derived monocyte/macrophage precursor cells (BMMs) are not clear. In the present study, we investigate the roles of TRPM7 in osteoclastogenesis using methods of small interfering RNA (siRNA), RT-PCR, patch-clamp, and calcium imaging. RANKL (receptor activator of NF-${\kappa}B$ ligand) stimulation did not affect the TRPM7 expression and TRPM7-mediated current was activated in HEK293, RAW264.7, and BMM cells by the regulation of $Mg^{2+}$. Knock-down of TRPM7 by siTRPM7 reduced intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) increases by 0 mM $[Mg^{2+}]_e$ in HEK293 cells and inhibited the generation of RANKL-induced $Ca^{2+}$ oscillations in RAW264.7 cells. Finally, knock-down of TRPM7 suppressed RANKL-mediated osteoclastogenesis such as activation and translocation of NFATc1, formation of multinucleated cells, and the bone resorptive activity, sequentially. These results suggest that TRPM7 plays an essential role in the RANKL-induced $[Ca^{2+}]_i$ oscillations that triggers the late stages of osteoclastogenesis.

Transient Knock Down of Grp78 Reveals Roles in Serum Ferritin Mediated Pro-inflammatory Cytokine Secretion in Rat Primary Activated Hepatic Stellate Cells

  • Wang, Chi-Mei;Li, Shan-Jen;Wu, Chi-Hao;Hu, Chien-Ming;Cheng, Hui-Wen;Chang, Jung-Su
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.605-610
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    • 2014
  • Chronic liver diseases, including cancer, are characterized by inflammation and elevated serum ferritin (SF). However, the causal-relationship remains unclear. This study used primary rat hepatic stellate cells (HSC) as a model to investigate effects of physiological SF concentrations (10, 100 and 1000 pM) because HSCs play a central role in the development and progression of liver fibrosis. Physiological concentrations of SF, either horse SF or human serum, induced pro-inflammatory cytokine $IL1{\beta}$, IL6 and $TNF{\alpha}$ secretion in rat activated HSCs (all p<0.05). By contrast, treatment did not alter activation marker ${\alpha}SMA$ expression. The presence of SF markedly enhanced expression of Grp78 mRNA (p<0.01). Furthermore, transient knock down of Grp78 by endotoxin EGF-SubA abolished SF-induced $IL1{\beta}$ and $TNF{\alpha}$ secretion in activated HSCs (all p<0.05). In conclusion, our results showed that at physiological concentrations SF functions as a pro-inflammatory mediator in primary rat HSCs. We also provide a molecular basis for the action of SF and identified Grp78-associated ER stress pathways as a novel potential therapeutic target for resolution of fibrosis and possible prevention of liver cancer.

소포체 스트레스에 대한 Protein Disulfide Isomerase의 세포보호효과 (Bombyx mori Protein Disulfide Isomerase (bPDI) Protects Sf9 Cells from Endoplasmic Reticulum (ER) Stress)

  • 구태원;윤은영;김성완;최광호;강석우;권기상;권오유
    • 생명과학회지
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    • 제17권8호통권88호
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    • pp.1129-1134
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    • 2007
  • bPDI가 ER내 misfolding 단백질의 생성을 제한함으로써 곤충변역과 관계하는지를 해석하기 위하여 bPDI가 과발현(overexpression)되는 곤충세포주와 이와 반대로 bPDI가 억제발현(knock-down)되는 곤충세포주를 제작하여 bPDI가 곤충면역에 관련하는지를 해석하였다. bPDI가 과발현되는 세포주 (Sf9-bPDI)는 정상세포주(Sf9)나 pIZT/V5-His 벡터만 도입된 세포주(Sf9-pIZT)에 비하여 생존율이 30% 이상 높았지만, bPDI의 전사체 발현이 억제된 세포주(Sf9-bPDI-dsRNA)는 오히려 정상세포주나 pIZT/V5-His 벡터만 도입된 세포주에 비하여 생존율이 약 15%낮았다. 이와 같은 결과로써, bPDI는 ER내 misfolding 단백질의 생성을 제한함으로써 곤충의 ERSE과 밀접하게 관련할 것이라 추정할 수 있었다.