Cell Signaling Technology

Product Pathways - Tyrosine Kinase / Adaptors

SignalSilence® HER2/ErbB2 siRNA II #6283

Applications Reactivity
Transfection H

Reactivity Key:  H=Human
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Western Blotting

Western Blotting

Western blot analysis of extracts from HeLa cells, transfected with 100 nM SignalSilence® Control siRNA (Unconjugated) #6568 (-), SignalSilence® HER2/ErbB2 siRNA I #6282 (+) or SignalSilence® HER2/ErbB2 siRNA II (+), using HER2/ErbB2 (29D8) Rabbit mAb #2165 (upper) or α-Tubulin (11H10) Rabbit mAb #2125 (lower). The HER2/ErbB2 (29D8) Rabbit mAb confirms silencing of HER2/ErbB2 expression, while the α-Tubulin (11H10) Rabbit mAb is used as a loading control.

Description

SignalSilence® HER2/ErbB2 siRNA II from Cell Signaling Technology (CST) allows the researcher to specifically inhibit HER2/ErbB2 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 HER2/ErbB2 siRNA II 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.

Each vial contains the equivalent of 100 transfections, which corresponds to a final siRNA concentration of 100 nM per transfection in a 24-well plate with a total volume of 300 μl per well.

Background

The ErbB2 (HER2) proto-oncogene encodes a 185 kDa transmembrane, receptor-like glycoprotein with intrinsic tyrosine kinase activity (1). While ErbB2 lacks an identified ligand, ErbB2 kinase activity can be activated in the absence of a ligand when overexpressed and through heteromeric associations with other ErbB family members (2). Amplification of the ErbB2 gene and overexpression of its product are detected in almost 40% of human breast cancers (3). Binding of the c-Cbl ubiquitin ligase to ErbB2 at Tyr1112 leads to ErbB2 poly-ubiquitination and enhances degradation of this kinase (4). ErbB2 is a key therapeutic target in the treatment of breast cancer and other carcinomas and targeting the regulation of ErbB2 degradation by the c-Cbl-regulated proteolytic pathway is one potential therapeutic strategy. Phosphorylation of the kinase domain residue Tyr877 of ErbB2 (homologous to Tyr416 of pp60c-Src) may be involved in regulating ErbB2 biological activity. The major autophosphorylation sites in ErbB2 are Tyr1248 and Tyr1221/1222; phosphorylation of these sites couples ErbB2 to the Ras-Raf-MAP kinase signal transduction pathway (1,5).

  1. Muthuswamy, S.K. et al. (1999) Mol Cell Biol 19, 6845-57.
  2. Qian, X. et al. (1994) Proc Natl Acad Sci USA 91, 1500-4.
  3. Dittadi, R. and Gion, M. (2000) J Natl Cancer Inst 92, 1443-4.
  4. Klapper, L.N. et al. (2000) Cancer Res 60, 3384-8.
  5. Kwon, Y.K. et al. (1997) J Neurosci 17, 8293-9.

Application References

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Companion Products

Limited Use Label License, RNA interference: This product is licensed under European Patent 1144623 and foreign equivalents from Ribopharma AG, Kulmbach, Germany and is provided only for use in non-commercial research specifically excluding use (a) in drug discovery or drug development, including target identification or target validation, by or on behalf of a commercial entity, (b) for contract research or commercial screening services, (c) for the production or manufacture of siRNA-related products for sale, or (d) for the generation of commercial databases for sale to Third Parties. Information about licenses for these and other commercial uses is available from Ribopharma AG, Fritz-Hornschuch-Str. 9, D-95326 Kulmbach, Germany.

For Research Use Only. Not For Use In Diagnostic Procedures.

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