Somatic overgrowth disorders of the PI3K/AKT/mTOR pathway & therapeutic strategies

The phosphatidylinositol‐3‐kinase (PI3K)/AKT/mTOR signaling pathway plays an essential role in regulation of normal cell growth, metabolism, and survival. Somatic activating mutations in the PI3K/AKT/mTOR pathway are among the most common mutations identified in cancer, and have been shown to cause a spectrum of overgrowth syndromes including PIK3CA‐Related Overgrowth Spectrum, Proteus syndrome, and brain overgrowth conditions. Clinical findings in these disorders may be isolated or multiple, including sporadic or mosaic overgrowth (adipose, skeletal, muscle, brain, vascular, or lymphatic), and skin abnormalities (including epidermal nevi, hyper‐, and hypopigmented lesions), and have the potential risk of tumorigenesis. Key negative regulators of the PI3K‐AKT signaling pathway include PTEN and TSC1/TSC2 and germline loss‐of function mutations of these genes are established to cause PTEN Hamartoma Tumor Syndrome and Tuberous Sclerosis Complex. Mosaic forms of these conditions lead to increased activation of PI3K and mTOR at affected sites and there is phenotypic overlap between these conditions. All are associated with significant morbidity with limited options for treatment other than symptomatic therapies and surgeries. As dysregulation of the PI3K/AKT/mTOR pathway has been implicated in cancer, several small molecule inhibitors targeting different components of the PI3K/AKT/mTOR signaling pathway are under clinical investigation. The development of these therapi...
Source: American Journal of Medical Genetics Part C: Seminars in Medical Genetics - Category: Genetics & Stem Cells Authors: Tags: Research Review Source Type: research