Endoderm Markers
Apolipoprotein E is essential for the normal catabolism of triglyceride rich lipoprotein constituents. The apolipoprotein E gene is mapped to chromosome 19 in a cluster with APOC1 and APOC2. Defects in Apolipoprotein E result in familial dysbetalipoproteinemia, or type III hyperlipoproteinemia (HLP III), in which increased plasma cholesterol and triglycerides are the consequence of impaired clearance of chylomicron and VLDL remnants.
CDX2
CDX2 is a caudal type homeobox gene that encodes an intestine-specific transcription factor that is expressed early in intestinal development and may be involved in the regulation of proliferation and differentiation of intestinal epithelial cells. It is expressed in the nuclei of epithelial cells throughout the intestine, from duodenum to rectum. The CDX2 protein is expressed in primary and metastatic colorectal carcinomas and has also been demonstrated in the intestinal metaplasia of the stomach and intestinal-type gastric cancer, while it is not expressed in the normal gastric mucosa. Studies have shown that CDX2 is superior marker compared to CK20.
FOXA2 peptide
This gene encodes a member of the forkhead class of DNA-binding proteins. These hepatocyte nuclear factors are transcriptional activators for liver-specific transcripts such as albumin and transthyretin, and they also interact with chromatin. Similar family members in mice have roles in the regulation of metabolism and in the differentiation of the pancreas and liver. This gene has been linked to sporatic cases of maturity-onset diabetes of the young. Two transcript variants encoding the same protein have been identified for this gene.
Ganglioside GD3
Almost all melanomas, astrocytomas,a proportion of sarcomas, a small number of carcinomas, some nevi, as well as normal melanocytes express GD3 antigen.
GATA4
GATA4 is a 46 kDa member of the GATA family of zinc finger-containing transcription factors that is involved in the development of cardiac hypertrophy and remodeling, and plays a critical role in regulating basal and agonist or stress-induced gene expression in cardiac and smooth muscle cell types. GATA4 contains a conserved MAPK phosphorylation site at serine 105 within the transcriptional activation domain. Serine 105 of GATA4 is phosphorylated in response to agonist stimulation through MEK 1-ERK1 / 2, and weakly through JNK or p38 MAPKs.
CD14
CD14 is a single copy gene encoding 2 protein forms: a 50 to 55 kDa glycosylphosphatidylinositol anchored membrane protein (mCD14) and a monocyte or liver derived soluble serum protein (sCD14) that lacks the anchor. Both molecules are critical for lipopolysaccharide (LPS) dependent signal transduction, and sCD14 confers LPS sensitivity to cells lacking mCD14. Increased sCD14 levels are associated with inflammatory infectious diseases and high mortality in gram negative shock. CD14 also appears to be involved in clearance of gram-negative bacteria via its high affinity binding to LPS-LPB complexes.
CD31
CD31, also known as platelet endothelial cell adhesion molecule 1 (PECAM1), is a type I integral membrane glycoprotein and a member of the immunoglobulin superfamily of cell surface receptors. It is constitutively expressed on the surface of endothelial cells, and concentrated at the junction between them. It is also weakly expressed on many peripheral lymphoid cells and platelets.
CD31 has been used to measure angiogenesis in association with tumor recurrence. Other studies have also indicated that CD31 and CD34 can be used as markers for myeloid progenitor cells and recognize different subsets of myeloid leukemia infiltrates (granular sarcomas).
CD 36
CD36 is a cell surface class B scavenger receptor. CD36 is preferentially found within lipid rafts, which facilitates its association with receptors, signalling and adapter molecules. CD36 binds to collagen, thrombospondin, anionic phospholipids and oxidized LDL. May function as a cell adhesion molecule. Directly mediates cyto adherence of Plasmodium falciparum parasitized erythrocytes. Binds long chain fatty acids and may function in the transport and/or as a regulator of fatty acid transport.
CXCR4
CXCR4 (fusin, LESTR or HUMSTR) is a principal coreceptor for T cell tropic strains of HIV1 fusion and entry of human white blood cells. CXCR4 is also required for the infection by dual-tropic strains of HIV1 and mediates CD4 independent infection by HIV2. The a chemokine SDF1 is the ligand for CXCR4 and prevents infection by T tropic HIV1. CXCR4 associates with the surface CD4-gp120 complex before HIV enters target cells. CXCR4 messenger RNA levels correlated with HIV1 permissiveness in diverse human cell types. Antibodies to CXCR4 block HIV1 and HIV2 fusion and infection of human target cells. The amino terminal domain and the second extracellular loop of CXCR4 serve as HIV biding sites. CXCR4 is highly expressed in brain and heart, and in white blood cells, vascular endothelial cells, and umbilical cord endothelial cells.
VE Cadherin
Cadherins are calcium dependent cell adhesion proteins. They preferentially interact with themselves in a homophilic manner in connecting cells; cadherins may thus contribute to the sorting of heterogeneous cell types. This cadherin may play an important role in endothelial cell biology through control of the cohesion and organization of the intercellular junctions. It associates with alpha catenin forming a link to the cytoskeleton.
VEGF
VEGF receptor 2 is a member of a receptor tyrosine kinase family whose activation plays an essential role in a large number of biological processes such as embryonic development, wound healing, cell proliferation, migration and differentiation. Like other growth factor receptors, upon ligand binding VEGF receptor 2 dimerizes and is autophosphorylated on multiple tyrosine residues. These sites can be involved in the regulation of kinase activity or serve as binding sites for SH2 and phosphotyrosine binding containing signalling proteins. Phosphorylation of Tyrosines 1054 and 1059 in the activation loop is required for activation of VEGF receptor 2 and its intrinsic tyrosine kinase activity.
Von Willerbrand
Von Willebrand Factor (VWF) was previously known as Factor VIII related antigenis. VWF is synthesized exclusively by endothelial cells and megakaryocytes, and stored in the intracellular granules or constitutively secreted into plasma. This glycoprotein functions as both an antihemophilic factor carrier and a platelet vessel wall mediator in the blood coagulation system. Important in the maintenance of homeostasis, it participates in platelet vessel wall interactions by forming a noncovalent complex with coagulation factor VIII at the site of vascular injury. The Von Willebrand factor has functional binding domains to platelet glycoprotein Ib, glycoprotein IIb/IIIa, collagen and heparin. Mutations in this gene or deficiencies in this protein result in Von Willebrand's disease. VWD is characterized by frequent bleeding (gingival, minor skin quantitative lacerations, menorrhagia, etc.).