Recent insights into the pathophysiology of mTOR pathway dysregulation

Abstract

Mechanistic target of rapamycin (mTOR) dysregulation is present in a variety of human pathologies including neurological disease, cancer, diabetes, and cardiac disease. Hyperactivation leads to increased protein synthesis and cell growth, which are essential for growth, development, and cancer. Inhibition of mTOR results in induction of autophagy, a cell survival mechanism thought to be deficient in neurodegeneration. Counteracting the balance of mTOR signaling with target specific inhibitors is of interest in pathological conditions where mTOR signaling is upregulated. The US Food and Drug Administration (FDA) has approved the use of rapamycin for treatment of renal cell, pancreatic neuroendocrine, and hormone positive breast cancer. Many clinical trials are underway to determine the efficacy of mTOR inhibitors in other pathologies as monotherapies or combinational therapies with chemotherapeutics, tyrosine kinase inhibitors, molecular targeted therapies, and vascular endothelial growth factor (VEGF) inhibitors. Collectively, this review is an overview of the current practices and outcomes of pharmaceutically targeting this highly studied mediator of normal and aberrant cell function.