Product Pathways - Tyrosine Kinase / Adaptors
SignalSilence® HER3/ErbB3 siRNA II #6422
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.
Western blot analysis of extracts from OVCAR8 cells, transfected with 100 nM SignalSilence® Control siRNA (Unconjugated) #6568 (-), SignalSilence® HER3/ErbB3 siRNA I #6504 (+) or SignalSilence® HER3/ErbB3 siRNA II (+), using HER3/ErbB3 (1B2E) Rabbit mAb #4754 (upper) or α-Tubulin (11H10) Rabbit mAb #2125 (lower). The HER3/ErbB3 (1B2E) Rabbit mAb confirms silencing of HER3/ErbB3 expression, while the α-Tubulin (11H10) Rabbit mAb is used as a loading control.
SignalSilence® HER3/ErbB3 siRNA II from Cell Signaling Technology (CST) allows the researcher to specifically inhibit HER3/ErbB3 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.
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 HER3/ErbB3 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.
HER3/ErbB3 is a member of the ErbB receptor protein tyrosine kinase family, but it lacks tyrosine kinase activity. Tyrosine phosphorylation of ErbB3 depends on its association with other ErbB tyrosine kinases. Upon ligand binding, heterodimers form between ErbB3 and other ErbB proteins, and ErbB3 is phosphorylated on tyrosine residues by the activated ErbB kinase (1,2). There are at least 9 potential tyrosine phosphorylation sites in the carboxy-terminal tail of ErbB3. These sites serve as consensus binding sites for signal transducing proteins, including Src family members, Grb2, and the p85 subunit of PI3 kinase, which mediate ErbB downstream signaling (3). Both Tyr1222 and Tyr1289 of ErbB3 reside within a YXXM motif and participate in signaling to PI3K (4).Investigators have found that ErbB3 is highly expressed in many cancer cells (5) and activation of the ErbB3/PI3K pathway is correlated with malignant phenotypes of adenocarcinomas (6). Research studies have demonstrated that in tumor development, ErbB3 may function as an oncogenic unit together with other ErbB members (e.g. ErbB2 requires ErbB3 to drive breast tumor cell proliferation) (7). Thus, investigators view inhibiting interaction between ErbB3 and ErbB tyrosine kinases as a novel strategy for anti-tumor therapy.
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- Guy, P.M. et al. (1994) Proc. Natl. Acad. Sci. USA 91, 8132-8136.
- Songyang, Z. et al. (1993) Cell 72, 767-778.
- Kim, H.H. et al. (1994) J. Biol. Chem. 269, 24747-24755.
- Sithanandam, G. et al. (2003) Carcinogenesis 24, 1581-1592.
- Kobayashi, M. et al. (2003) Oncogene 22, 1294-1301.
- Holbro, T. et al. (2003) Proc. Natl. Acad. Sci. USA 100, 8933-8938.
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- 6568 SignalSilence® Control siRNA (Unconjugated)
- 6201 SignalSilence® Control siRNA (Fluorescein Conjugate)
- 6504 SignalSilence® HER3/ErbB3 siRNA I
- 4754 HER3/ErbB3 (1B2E) Rabbit mAb
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.