Tissue polypeptide antigen

Lutz W, Krajewska B, Pilacic B. 1997. Determination of tissue polypeptide antigens (TPA) and carcinoembryonic antigen (CEA) in semm Its value in the preliminary cancer risk assessment in asbestos exposed workers. Int J Occup Med Environ Health 10 259-265. 

A chest X-ray cannot detect the asbestos fibers themselves, but it can detect early signs of lung disease caused by asbestos from relatively heavy exposure. The most reliable test for asbestos exposure is the detection of microscopic asbestos fibers in pieces of lung tissue removed by surgery (invasive test). The use of biological markers, such as tissue polypeptide antigen, may play a useful role in the early detection of mesothelioma in individuals at risk. 

Cytokeratin 8 (CK 8) is an intermediate filament type II and one of the first cytokeratins expressed in the embryonal tissue and persists throughout the adult tissue. CK 8 is encoded on chromosome 12 and expressed in the vast majority of adenocarcinomas including lung, breast, gastrointestinal adenocarcinoma in addition to transitional, neuroendocrine and hepatocellular carcinoma, but is not detectable in squamous epithelium. CK 8 is also known as tissue polypeptide antigen (TPA) detectable in serum of cancer patients. 

A further interesting protein characteristic for breast tissue is NY-BR-1. NY-BR-1 is a differentiation antigen expressed in normal breast tissue and epithelial breast tumors in addition to testicular parenchyma and brain tissue. NY-BR-1 is a nuclear polypeptide functioning as transcription factor encoded by a gene located on chromosome lOpll-12. 

Snake venoms a mixture of toxins produced in the venom glands (parotid gland, or salivary gland of the upper jaw) of venomous snakes (asps or hooded snakes, e.g. the cobra sea snakes vipers, e.g. puff adder, rattlesnake). They consist of highly toxic, antigenic polypeptides and proteins (which cause paralysis and death of the prey), and enzymes (which facilitate the spread of the toxins, and initiate digestion of undivided swallowed prey). The enzymes indude hya-luronidase (promotes spread of toxins), ATPase and acetylcholine esterase (paralysis), phospholipases (hemolysis), proteinases and L-amino add oxidases (tissue necrosis and blood clotting). 

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