Temsirolimus, sold under the brand name Torisel, is an intravenous drug for the treatment of renal cell carcinoma (RCC), developed by Wyeth Pharmaceuticals and approved by the U.S. Food and Drug Administration (FDA) in May 2007, and was also approved by the European Medicines Agency (EMA) in November 2007. It is a derivative and prodrug of sirolimus. Mechanism of action
Temsirolimus is a specific inhibitor of mTOR and interferes with the synthesis of proteins that regulate proliferation, growth, and survival of tumor cells. Though temsirolimus shows activity on its own, it is also known to be converted to  sirolimus (rapamycin) in vivo; therefore, its activity may be more attributed to its metabolite rather than the prodrug itself (despite claims to the contrary by the manufacturer). Treatment with temsirolimus leads to cell cycle arrest in the G1 phase, and also inhibits tumor angiogenesis by reducing synthesis of VEGF.mTOR (mammalian target of rapamycin) is a kinase enzyme inside the cell that collects and interprets the numerous and varied growth and survival signals received by tumor cells. When the kinase activity of mTOR is activated, its downstream effectors, the synthesis of cell cycle proteins such as cyclin D and hypoxia-inducible factor-1a (HIF-1a) are increased. HIF-1a then stimulates VEGF. Whether or not mTOR kinase is activated, determines whether the tumor cell produces key proteins needed for proliferation, growth, survival, and angiogenesis.mTOR is activated in tumor cells by various mechanisms including growth factor surface receptor tyrosine kinases, oncogenes, and loss of tumor suppressor genes.
Lichen myxedematosus is a group of cutaneous disorders considered mucinoses. : 183   Conditions included in this group are:: 183 
Generalized lichen myxedematosus
Localized lichen myxedematosusDiscrete papular lichen myxedematosus
Acral persistent papular mucinosis
Self-healing papular mucinosisSelf-healing juvenile cutaneous mucinosisPapular mucinosis of infancy
Atypical lichen myxedematosus
Atypical tuberous myxedema

See also
List of cutaneous conditions

References


== External links ==