Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42345 (mTOR)
 26,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

mTOR is a major biological switch, coordinating an adequate response to changes in energy uptake (amino acids, glucose), growth signals (hormones, growth factors) and environmental stress. mTOR kinase is highly conserved through evolution from yeast to man and in both cases, controls autophagy and cellular translation in response to nutrient stress. mTOR kinase is the catalytic component of two distinct multiprotein complexes called mTORC1 and mTORC2. In addition to mTOR, mTORC1 contains Raptor, mLST8 and PRAS40. mTORC2 contains mTOR, Rictor, mSIN1 and Protor-1. mTORC1 activates p70S6K, which in turn phosphorylates the ribosomal protein S6 and 4E-BP1, both involved in protein translation. mTORC2 activates AKT directly by phosphorylating Serine 473. pAKT(S473) phosphorylates TSC2 (tuberin) and inactivates it, preventing its association with TSC1 (hamartin) and the inhibition of Rheb, an activator of mTOR. pAKT also phosphorylates PRAS40, releasing it from the mTORC1 complex, increasing its kinase activity. Finally, AKT regulates FOXO3 phosphorylation, sequestering it in the cytosol in an inactive state.
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PMID:Simultaneous inhibition of mTORC1 and mTORC2 by mTOR kinase inhibitor AZD8055 induces autophagy and cell death in cancer cells. 2036 13

Lymphangioleiomyomatosis (LAM), a rare cystic lung disease with multi-organ involvement, occurs primarily in women of childbearing age. LAM can present sporadically or in association with tuberous sclerosis complex (TSC). Loss of lung function in patients with LAM can be attributed to the dysregulated growth of LAM cells, with dysfunctional TSC1 or TSC2 genes, which encode hamartin and tuberin, respectively, leading to hyperactivation of the mammalian target of rapamycin (mTOR). LAM cells are smooth muscle-like cells that express melanoma antigens such as gp100, a splice variant of the Pmel17 gene. Tuberin and hamartin form heterodimers that act as negative regulators of mTOR. Lack of TSC2 function, as occurs in LAM cells, leads to the production of the chemokine CCL2/monocyte chemotactic protein 1 (MCP-1), which increases LAM cell mobility. Although many chemokines and their receptors could influence LAM cell mobilization, we propose that a positive-feedback loop is generated when dysfunctional TSC2 is present in LAM cells. We identified a group of chemokine receptors that is expressed in LAM cells and differs from those on smooth muscle and melanoma cells (Malme-3M). Chemokines have been implicated in tumor metastasis, and our data suggest a role for chemokines in LAM cell mobilization and thereby in the pathogenesis of LAM.
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PMID:The role of chemokines in migration of metastatic-like lymphangioleiomyomatosis cells. 2066 8

Tuberous sclerosis complex is a genetic multisystem disease characterized by hamartic development of many organs, most notably the brain, heart, kidneys, lungs, and skin. This autosomic dominant disorder results from mutations in one of two genes, TSC1 and TSC2, coding for hamartin and tuberin, respectively. The hamartin-tuberin complex inhibits the mammalian target of rapamycin pathway, which controls cell growth and proliferation. The clinical presentation is highly variable and most features of tuberous sclerosis become evident only in childhood after the child is several years of age, limiting their usefulness for early diagnosis. The aim of this article is to define the pediatric clinical manifestations of tuberous sclerosis in correlation with patient age. Sometimes, a prenatal diagnosis can be made based on fetal ultrasound and MRI, which show cardiac and brain lesions. However, newborns are most often asymptomatic. In the 1st year, seizures are the most common symptoms, with a high incidence of infantile spasms. In children between 2 and 10 years of age, neurological symptoms are the most frequent with epilepsy, mental retardation, and autism, but extraneurological manifestations can be diagnosed. In adolescents, most features of tuberous sclerosis become evident and renal and pulmonary manifestations must be sought. The knowledge of age-dependent clinical features of tuberous sclerosis can provide an earlier diagnosis and improve the management of these patients with a special role for multidisciplinary consultation.
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PMID:[Characteristics of tuberous sclerosis in children]. 2070 8

Tuberous sclerosis complex (TSC) is an autosomal dominant, multisystem disease characterized by the development of multiple hamartomas and benign or rarely malignant neoplasms distributed at various sites throughout the body, especially in the brain, skin, retina, kidney, heart, and lungs. Brain lesions in TSC include: cortical/subcortical glioneuronal tubers, subependymal glial nodules (SENs), and subependymal giant cell astrocytomas (SEGAs). Cortical tubers are characterized by a markedly disorganized cortical lamination with dysplastic aggregates of abnormal glial and neuronal elements, including giant cells. SENs consist of large cells, somewhat similar to the giant cells seen in tubers, accompanied by elongated glial cells. SENs are typically covered by a layer of ependyma and can grow over time and develop into subependymal giant cell astrocytomas. SEGAs consist of a mixed cell population of large ganglioid-like cells, spindle and giant cells with nuclear pleomorphism. Mitotic activity and necrosis might be observed in SEGAs but they should not be considered as features of malignancy. The clinical presentations of TSC result from mutations in either of two tumour suppressor genes: TSC1 (located on 9q34) or TSC2 (located on 16p13). The proteins encoded by TSC1 and TSC2 genes, hamartin and tuberin, respectively, form a heterodimer which suppresses the mammalian target of rapamycin (mTOR), a major cell growth and proliferation controller. Oral rapamycin therapy may induce regression of astrocytomas associated with TSC. In this review, the clinicopathological features of TCS and recent advantages in the diagnosis and genetics of TSC are presented.
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PMID:Brain lesions in tuberous sclerosis complex. Review. 2092 98

Tuberous Sclerosis Complex (TSC) is an autosomal dominant, multi-system disorder, typically involving severe neurological symptoms, such as epilepsy, cognitive deficits and autism. Two genes, TSC1 and TSC2, encoding the proteins hamartin and tuberin, respectively, have been identified as causing TSC. Although there is a substantial overlap in the clinical phenotype produced by TSC1 and TSC2 mutations, accumulating evidence indicates that TSC2 mutations cause more severe neurological manifestations than TSC1 mutations. In this study, the neurological phenotype of a novel mouse model involving conditional inactivation of the Tsc2 gene in glial-fibrillary acidic protein (GFAP)-positive cells (Tsc2(GFAP1)CKO mice) was characterized and compared with previously generated Tsc1(GFAP1)CKO mice. Similar to Tsc1(GFAP1)CKO mice, Tsc2(GFAP1)CKO mice exhibited epilepsy, premature death, progressive megencephaly, diffuse glial proliferation, dispersion of hippocampal pyramidal cells and decreased astrocyte glutamate transporter expression. However, Tsc2(GFAP1)CKO mice had an earlier onset and higher frequency of seizures, as well as significantly more severe histological abnormalities, compared with Tsc1(GFAP1)CKO mice. The differences between Tsc1(GFAP1)CKO and Tsc2(GFAP1)CKO mice were correlated with higher levels of mammalian target of rapamycin (mTOR) activation in Tsc2(GFAP1)CKO mice and were reversed by the mTOR inhibitor, rapamycin. These findings provide novel evidence in mouse models that Tsc2 mutations intrinsically cause a more severe neurological phenotype than Tsc1 mutations and suggest that the difference in phenotype may be related to the degree to which Tsc1 and Tsc2 inactivation causes abnormal mTOR activation.
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PMID:Tsc2 gene inactivation causes a more severe epilepsy phenotype than Tsc1 inactivation in a mouse model of tuberous sclerosis complex. 2106 1

Tuberous sclerosis complex (TSC) is a neurogenetic disorder that often causes brain abnormalities leading to epilepsy, developmental delay, and autism. TSC is caused by inactivating mutations in either of the genes encoding the proteins hamartin (TSC1) and tuberin (TSC2). These proteins form a heterodimer that inhibits the mammalian target of rapamycin complex 1 (mTORC1) pathway, controlling translation and cell growth. Loss of either protein results in dysregulated mTORC1 activation, an important aspect of TSC pathogenesis. About thirty percent of TSC patients have cerebellar pathology that is poorly understood. To investigate the effects of TSC on the cerebellum, we created a mouse model in which the Tsc2 gene was selectively deleted from Purkinje cells starting at postnatal day 6 (P6). The loss of Tsc2 caused a progressive increase in Purkinje cell size and subsequent death from apoptosis. Purkinje cell loss was predominantly cell type specific and associated with motor deficits. Immunohistochemical analysis showed that both endoplasmic reticulum (ER) and oxidative stress were increased in Tsc2-null Purkinje cells. The cell death and ER stress phenotypes were rescued by treatment with the mTORC1 inhibitor rapamycin. To assess whether the murine Purkinje cell loss has a correlate to the human TSC, we analyzed postmortem cerebellum samples from TSC patients and detected Purkinje cell loss in half of the samples. Our results establish a critical role for the TSC complex in Purkinje cell survival by regulating ER and oxidative stress and reveal a novel aspect of TSC neuropathology.
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PMID:Loss of the tuberous sclerosis complex protein tuberin causes Purkinje cell degeneration. 2141 48

Mutations in genes encoding either hamartin [TSC1 (tuberous sclerosis complex 1)] or tuberin (TSC2) result in a multisystem disorder characterized by the development of benign tumours and hamartomas in several organs. The TSC1 and TSC2 proteins form a complex that lies at the crossroad of many signalling pathways integrating the energy status of the cell with signals induced by nutrients and growth factors. The TSC1/2 complex is a critical negative regulator of mTORC1 [mTOR (mammalian target of rapamycin) complex 1], and by that controls anabolic processes to promote cell growth, proliferation and survival. In the present paper, we review recent evidence highlighting the notion that the TSC1/2 complex simultaneously controls mTOR-dependent and mTOR-independent signals critical for the balancing of cell proliferation and cell death.
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PMID:The tuberous sclerosis complex: balancing proliferation and survival. 2142 21

Tuberous Sclerosis Complex (TSC) is an inherited disorder resulting from mutations in one of two tumor suppressor genes: TSC1 (hamartin) and TSC2 (tuberin). Hamartin and tuberin, the protein products of TSC1 and TSC2, form a functional protein complex in the mTOR pathway that controls cell growth and proliferation. Epilepsy is the most common disorder in TSC, frequently associated with intractable and early onset seizures, and often as infantile spasms. Epilepsy surgery is an option for TSC patients with medically intractable epilepsy. Multimodality neuroimaging has improved the detection of epileptogenic foci, allowing an increased number of TSC patients to be evaluated noninvasively for resective surgery. Advances in understanding of the molecular pathogenesis of the TSC are crucial to establish new therapeutic approaches for individuals with TSC.
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PMID:Tuberous sclerosis and epilepsy. 2151 26

Tuberous sclerosis (TS) is the second most common genodermatosis in our country and one of its main characteristics is the presence of facial angiofibromas. These benign tumors can be really bothersome for some patients and there is not a gold-standard treatment. Laser therapy has been used with good responses but it is a painful option and recurrence is guaranteed. TS develops as a result of a mutation of one of two genes, TSC1 or TSC2, which encode for hamartin and tuberin, respectively. TSC1 and TSC2 are tumor suppressors that inhibit mTOR, which if mutated results in mTOR activation, leading to an increase in protein translation. This eventually induces formation of hamartomatous tumors in patients with TSC. Oral rapamycin had been reported to be effective for the treatment of various tumors, apparently because of its action of inhibiting the m-TOR complex. Recently it has been suggested that the drug may be effective when applied topically. We report the 6th case of facial AF treated with topical rapamycin, 1 percent, once per day. An excellent response was achieved surprisingly rapidly. We propose this option as a safe and effective therapy.
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PMID:Facial angiofibromas treated with topical rapamycin: an excellent choice with fast response. 2230 Oct 52

Tuberous sclerosis complex is a genetic disorder characterized by the formation of nonmalignant hamartomas in the brain, heart, skin, kidney, lung, and other organs. It is associated with autism, epilepsy, and other neurocognitive and behavioral disabilities. Wide phenotypic variation occurs in disease severity and natural course: some patients demonstrate minimal effects, e.g., skin changes; others manifest profound seizures and mental retardation. Tuberous sclerosis complex is caused by mutations in either the tuberous sclerosis complex 1 or 2 gene (coding for hamartin and tuberin, respectively). The tuberous sclerosis complex 1/tuberous sclerosis complex 2 protein dimer complex is a crucial inhibitory element in the mammalian target of rapamycin pathway, regulating cell growth and proliferation. Until recently, few options existed, other than surgery, for treating symptoms of tuberous sclerosis complex related to the growth of hamartomas. Increased understanding of the genetic cause of the disease and underlying dysregulation of the mammalian target of rapamycin pathway has led to clinical trials of mammalian target of rapamycin inhibitors, including sirolimus and everolimus. This review gives an overview of tuberous sclerosis complex and its molecular causes, and summarizes results from recent clinical trials of mammalian target of rapamycin inhibitors in patients with the disease.
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PMID:Emerging treatments in the management of tuberous sclerosis complex. 2252 Mar 46


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