Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Western Blotting
Background: Tissue Factor (TF)/CD142 (Coagulation factor III/Thromboplastin) is a type-I transmembrane glycoprotein that serves as the cell surface receptor and cofactor for blood coagulation factors VII and VIIa, and thus plays a central role in hemostasis and thrombosis (1). The TF:VIIa receptor-ligand complex is widely recognized as the initiator of the extrinsic blood coagulation protease cascade, which ultimately leads to the generation of fibrin and thrombin (1). A member of the type-II cytokine receptor superfamily, TF has also been shown to engage the PI3K (2) and MAPK (3) signaling cascades upon binding to factor VIIa in order to drive cellular responses such as cell migration, growth, and proliferation. Although the function of TF under physiologic conditions is to coordinate blood clotting in response to tissue damage, TF is implicated in pathologic conditions such as tumorigenesis. Indeed, TF is aberrantly expressed in colorectal cancer, breast cancer, pancreatic cancer, and glioblastoma multiforme (4). It has been shown to promote tumor angiogenesis, tumor growth, metastasis, and venous thrombosis (5). Given that TF overexpression is associated with numerous types of solid tumors, it has garnered much attention as a potential therapeutic target.
Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting
Background: c-Kit is a member of the subfamily of receptor tyrosine kinases that includes PDGF, CSF-1, and FLT3/flk-2 receptors (1,2). It plays a critical role in activation and growth in a number of cell types including hematopoietic stem cells, mast cells, melanocytes, and germ cells (3). Upon binding with its stem cell factor (SCF) ligand, c-Kit undergoes dimerization/oligomerization and autophosphorylation. Activation of c-Kit results in the recruitment and tyrosine phosphorylation of downstream SH2-containing signaling components including PLCγ, the p85 subunit of PI3 kinase, SHP2, and CrkL (4). Molecular lesions that impair the kinase activity of c-Kit are associated with a variety of developmental disorders (5), and mutations that constitutively activate c-Kit can lead to pathogenesis of mastocytosis and gastrointestinal stromal tumors (6). Tyr719 is located in the kinase insert region of the catalytic domain. c-Kit phosphorylated at Tyr719 binds to the p85 subunit of PI3 kinase in vitro and in vivo (7).