SignalSilence? CTCF siRNA I

• 产品编号：CST-6265S      品牌：CST       原厂货号：6265S
• 产品分类：DNA和RNA纯化 > RNA干扰 > RNAi Oligos > siRNA
• 应用分类：

描述：

来自Cell Signaling Technology (CST)公司的SignalSilence® CTCF siRNA I可以帮助研究者通过RNA干扰特异性地抑制CTCF蛋白表达，这种方法可以通过将双链RNA分子传递到细胞内从而使基因表达有选择的沉默。来自CST的所有的SignalSilence^®siRNA产品都是经过内部严格检测的，并且通过Western blot 分析证明确实能够减少目的蛋白的表达。通过三苯甲基分析每个碱基以监测寡核苷酸的合成，确保合适的配对效率。随后寡核苷酸通过亲和固相萃取法纯化。退火的RNA双链通过质谱分析来证实其精确的组成。每一批产品都通过质谱分析与前面的产品进行比较，来保证不同批次之间的最大一致性。CST公司推荐使用100 nM CTCF siRNA I进行转染。转染步骤按照转染试剂说明书提供的步骤进行。遇到任何使用方面的问题，请随时联系CST。CCCTC-binding factor (CTCF)和它的横向同源物Brother of the Regulator of Imprinted Sites (BORIS)都是高度保守的转录因子，它们具有调节转录激活和抑制、绝缘子功能和印迹调控区域(Imprinting control regions,. ICRs) (1-4)。虽然它们有不同的氨基和羧基端，但是这两个蛋白都含有11个保守的锌指结构，这些结果可以联合结合到同一个DNA元件(1)。CTCF是广泛表达的，并且有助于细胞生长调节基因的转录调控，包括c-myc、p19/ARF、p16/INK4A、BRCA1、p53、p27、E2F1和TERT (1)。对于所有已知的绝缘子和ICRs包括H19/IgF2、Prader-Willi/Angelman syndrome和Inactive X-Specific Transcript (XIST) anti-sense loci的增强子的封闭活性，CTCF能够结合到它们并且是被需要的 (5-7)。CTCF与DNA的结合是对DNA的甲基化很敏感，甲基化是一个标记物，它能确定印记等位基因(母方vs.父方)的选择(1)。CTCF的不同功能通过至少两个不同的翻译后修饰来调节。CTCF的多聚腺苷酸二磷酸核糖基化反应对于绝缘子功能是需要的(8)。通过蛋白激酶CK2使在Ser612位点的磷酸化有助于在c-myc启动子中CTCF从一个转录抑制子到转录激活因子的开关作用(9)。CTCF的突变或截短在许多乳腺、前列腺和Wilms tumors中被发现(10,11)。BORIS的表达仅限于精母细胞，并且是与CTCF相互排斥的(3)。在表达BORIS的细胞中，X染色体相关的癌肿睾丸抗原例如MAGE-1A的启动子都被去甲基化并且激活，然而在CTCF表达的体细胞中是甲基化并且失活(12)。像其它睾丸特异性蛋白一样，BORIS在不同的癌症中不正常的表达例如乳腺癌，并且比CTCF对DNA结合位点有更大的亲和力，这可以减弱CTCF的潜在肿瘤抑制活性(1,3,13,14)。

1. Klenova, E.M. et al. (2002) Semin Cancer Biol 12, 399-414.
2. Klenova, E.M. et al. (1993) Mol Cell Biol 13, 7612-24.
3. Loukinov, D.I. et al. (2002) Proc Natl Acad Sci USA 99, 6806-11.
4. Mukhopadhyay, R. et al. (2004) Genome Res 14, 1594-602.
5. Hark, A.T. et al. (2000) Nature 405, 486-9.
6. Ohta, T. et al. (1999) Am J Hum Genet 64, 397-413.
7. Chao, W. et al. (2002) Science 295, 345-7.
8. Yu, W. et al. (2004) Nat Genet 36, 1105-10.
9. El-Kady, A. and Klenova, E. (2005) FEBS Lett 579, 1424-34.
10. Filippova, G.N. et al. (1998) Genes Chromosomes Cancer 22, 26-36.
11. Filippova, G.N. et al. (2002) Cancer Res 62, 48-52.
12. Vatolin, S. et al. (2005) Cancer Res 65, 7751-62.
13. Hong, J.A. et al. (2005) Cancer Res 65, 7763-74.
14. D'Arcy, V. et al. (2008) Br J Cancer 98, 571-9.

原厂资料：

Description

SignalSilence® CTCF siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit CTCF expression using RNA interference, a method whereby gene expression can be selectively silenced through the delivery of double stranded RNA molecules into the cell. All SignalSilence® siRNA products from CST are rigorously tested in-house and have been shown to reduce target protein expression by western analysis.

Quality Control

Oligonucleotide synthesis is monitored base by base through trityl analysis to ensure appropriate coupling efficiency. The oligo is subsequently purified by affinity-solid phase extraction. The annealed RNA duplex is further analyzed by mass spectrometry to verify the exact composition of the duplex. Each lot is compared to the previous lot by mass spectrometry to ensure maximum lot-to-lot consistency.

Directions for Use

CST recommends transfection with 100 nM CTCF siRNA I 48 to 72 hours prior to cell lysis. For transfection procedure, follow protocol provided by the transfection reagent manufacturer. Please feel free to contact CST with any questions on use.

Background

CCCTC-binding factor (CTCF) and its paralog, the Brother of the Regulator of Imprinted Sites (BORIS), are highly conserved transcription factors that regulate transcriptional activation and repression, insulator function, and imprinting control regions (ICRs) (1-4). Although they have divergent amino and carboxy termini, both proteins contain 11 conserved zinc finger domains that work in combination to bind the same DNA elements (1). CTCF is ubiquitously expressed and contributes to transcriptional regulation of cell-growth regulated genes, including c-myc, p19/ARF, p16/INK4A, BRCA1, p53, p27, E2F1, and TERT (1). CTCF also binds to and is required for the enhancer-blocking activity of all known insulator elements and ICRs, including the H19/IgF2, Prader-Willi/Angelman syndrome, and Inactive X-Specific Transcript (XIST) anti-sense loci (5-7). CTCF DNA-binding is sensitive to DNA methylation, a mark that determines selection of the imprinted allele (maternal vs. paternal) (1). The various functions of CTCF are regulated by at least two different post-translational modifications. Poly(ADP-ribosyl)ation of CTCF is required for insulator function (8). Phosphorylation of Ser612 by protein kinase CK2 facilitates a switch of CTCF from a transcriptional repressor to an activator at the c-myc promoter (9). CTCF mutations or deletions have been found in many breast, prostate, and Wilms tumors (10,11). Expression of BORIS is restricted to spermatocytes and is mutually exclusive of CTCF (3). In cells expressing BORIS, promoters of X-linked cancer-testis antigens like MAGE-1A are demethylated and activated, but methylated and inactive in CTCF-expressing somatic cells (12). Like other testis specific proteins, BORIS is abnormally expressed in different cancers, such as breast cancer, and has a greater affinity than CTCF for DNA binding sites, detracting from CTCF’s potential tumor suppressing activity (1,3,13,14).

1. Klenova, E.M. et al. (2002) Semin Cancer Biol 12, 399-414.
2. Klenova, E.M. et al. (1993) Mol Cell Biol 13, 7612-24.
3. Loukinov, D.I. et al. (2002) Proc Natl Acad Sci USA 99, 6806-11.
4. Mukhopadhyay, R. et al. (2004) Genome Res 14, 1594-602.
5. Hark, A.T. et al. (2000) Nature 405, 486-9.
6. Ohta, T. et al. (1999) Am J Hum Genet 64, 397-413.
7. Chao, W. et al. (2002) Science 295, 345-7.
8. Yu, W. et al. (2004) Nat Genet 36, 1105-10.
9. El-Kady, A. and Klenova, E. (2005) FEBS Lett 579, 1424-34.
10. Filippova, G.N. et al. (1998) Genes Chromosomes Cancer 22, 26-36.
11. Filippova, G.N. et al. (2002) Cancer Res 62, 48-52.
12. Vatolin, S. et al. (2005) Cancer Res 65, 7751-62.
13. Hong, J.A. et al. (2005) Cancer Res 65, 7763-74.
14. D'Arcy, V. et al. (2008) Br J Cancer 98, 571-9.

注意事项：

Storage: CTCF siRNA I is supplied in RNAse-free water. Aliquot
and store at -20ºC.