mTOR signaling pathway and mTOR inhibitors in the treatment of cancer

Mammalian target of rapamycin (mTOR) plays a majorrole in the regulation of protein translation, cell growth,and metabolism. Three basic signalling pathways thathave been described as important in cancer including thephosphatidylinositol 3-kinase (PI3K)/AKT/mTOR kinasecascade, the protein kinase C (PKC) family, and the mitogen-activated protein kinase (MAPK)/Ras signalling cascades.mTOR has been defined as a key kinase actingdownstream of the activation of PI3K/AKT. These pathwaysare frequently deteriorated in cancer, and thereforemTOR inhibition is a important antitumor target. mTORinhibitors include rapamycin (i.e. sirolimus) and its derivatives;temsirolimus, everolimus, ridaforolimus and deforolimus.mTOR inhibitors has the important potential toprovide anticancer activity in many tumor types.Key words: PI3K/AKT/mTOR, mTOR inhibitors, cancer