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)

Germline mutation of the tumor suppressor gene CDC73 confers susceptibility to the hyperparathyroidism-jaw tumor syndrome associated with a high risk of parathyroid malignancy. Inactivating CDC73 mutations have also been implicated in sporadic parathyroid cancer, but are rare in sporadic benign parathyroid tumors. The molecular pathways that distinguish malignant from benign parathyroid transformation remain elusive. We previously showed that a hypomorphic allele of hyrax (hyx), the Drosophila homolog of CDC73, rescues the loss-of-ventral-eye phenotype of lobe, encoding the fly homolog of Akt1s1/ PRAS40. We report now an interaction between hyx and Tor, a central regulator of cell growth and autophagy, and show that eukaryotic translation initiation factor 4E-binding protein (EIF4EBP), a translational repressor and effector of mammalian target of rapamycin (mTOR), is a conserved target of hyx/CDC73. Flies heterozygous for Tor and hyx, but not Mnn1, the homolog of the multiple endocrine neoplasia type 1 (MEN1) tumor suppressor associated with benign parathyroid tumors, are starvation resistant with reduced basal levels of Thor/4E-BP. Human peripheral blood cell levels of EIF4EBP3 were reduced in patients with CDC73, but not MEN1, heterozygosity. Chromatin immunoprecipitation demonstrated occupancy of EIF4EBP3 by endogenous parafibromin. These results show that EIF4EBP3 is a peripheral marker of CDC73 function distinct from MEN1-regulated pathways, and suggest a model whereby starvation resistance and/or translational de-repression contributes to parathyroid malignant transformation.
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PMID:The EIF4EBP3 translational repressor is a marker of CDC73 tumor suppressor haploinsufficiency in a parathyroid cancer syndrome. 2229 94

Parathyroid carcinoma is a rare endocrine malignancy with an estimated incidence of less than 1 per million population. Excessive secretion of parathyroid hormone, extremely high serum calcium level, and the deleterious effects of hypercalcaemia are the clinical manifestations of the disease. Up to 60% of patients develop multiple disease recurrences and although long-term survival is possible with palliative surgery, permanent remission is rarely achieved. Molecular drivers of sporadic parathyroid carcinoma have remained largely unknown. Previous studies, mostly based on familial cases of the disease, suggested potential roles for the tumour suppressor MEN1 and proto-oncogene RET in benign parathyroid tumourigenesis, while the tumour suppressor HRPT2 and proto-oncogene CCND1 may also act as drivers in parathyroid cancer. Here, we report the complete genomic analysis of a sporadic and recurring parathyroid carcinoma. Mutational landscapes of the primary and recurrent tumour specimens were analysed using high-throughput sequencing technologies. Such molecular profiling allowed for identification of somatic mutations never previously identified in this malignancy. These included single nucleotide point mutations in well-characterized cancer genes such as mTOR, MLL2, CDKN2C, and PIK3CA. Comparison of acquired mutations in patient-matched primary and recurrent tumours revealed loss of PIK3CA activating mutation during the evolution of the tumour from the primary to the recurrence. Structural variations leading to gene fusions and regions of copy loss and gain were identified at a single-base resolution. Loss of the short arm of chromosome 1, along with somatic missense and truncating mutations in CDKN2C and THRAP3, respectively, provides new evidence for the potential role of these genes as tumour suppressors in parathyroid cancer. The key somatic mutations identified in this study can serve as novel diagnostic markers as well as therapeutic targets.
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PMID:Complete genomic landscape of a recurring sporadic parathyroid carcinoma. 2361 56

Parathyroid carcinoma (PC) is an extremely rare malignancy lacking effective therapeutic intervention. We generated and analyzed whole-exome sequencing data from 17 patients to identify somatic and germline genetic alterations. A panel of selected genes was sequenced in a 7-tumor expansion cohort. We show that 47% (8 of 17) of the tumors harbor somatic mutations in the CDC73 tumor suppressor, with germline inactivating variants in 4 of the 8 patients. The PI3K/AKT/mTOR pathway was altered in 21% of the 24 cases, revealing a major oncogenic pathway in PC. We observed CCND1 amplification in 29% of the 17 patients, and a previously unreported recurrent mutation in putative kinase ADCK1. We identified the first sporadic PCs with somatic mutations in the Wnt canonical pathway, complementing previously described epigenetic mechanisms mediating Wnt activation. This is the largest genomic sequencing study of PC, and represents major progress toward a full molecular characterization of this rare malignancy to inform improved and individualized treatments.
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PMID:Genomic profiling reveals mutational landscape in parathyroid carcinomas. 2835 68

Parathyroid carcinoma (PC) is a rare neoplasia difficult to diagnose preoperatively. It mainly occurs as a sporadic disease but also as part of familial PHPT. At variance with patients with the benign counterpart, the phenotype of these patients is characterized by a severe primary hyperparathyroidism (PHPT). The clinical features are mostly due to the effects of the excessive secretion of PTH by the functioning tumor and hypercalcemia rather than to the tumor burden. The prognosis is poor and unmanageable hypercalcemia accounts for death in the majority of cases. The best chance of cure is surgery, although persistent or recurrent disease occurs in about 50% of patients. Somatic loss-of-function mutations of CDC73 gene, encoding parafibromin, are the most frequent genetic alterations occurring in PCs. Mutations of the PRUNE2 gene, alterations of the PI3K/AKT/mTOR pathway and amplification of the CCND1 gene have been recently detected in PCs. Alteration of microRNA profile and methylation pattern have been identified in PCs. The recent studies have better defined the genomic landscape of PCs and represent major progress toward a full molecular characterization of this neoplasia and development of novel therapeutic options.
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PMID:Parathyroid carcinoma: a clinical and genetic perspective. 2894 21

Parathyroid carcinoma (PC) is a rare endocrine malignancy, accounting for <1% of all cases of sporadic primary hyperparathyroidism (PHPT) and up to 15% in the hereditary hyperparathyroidism-jaw tumor syndrome. Genomic alterations identified in PC are mostly represented by CDC73 gene mutations, codifying for a loss-of-function protein termed parafibromin. Whole exome sequencing identified mutations in other genes, such as mTOR, KMT2D, CDKN2C, THRAP3, PIK3CA, and EZH2 genes, CCND1 gene amplification. The diagnosis of PC is quite difficult due to the lack of reliable clinical diagnostic criteria, and in the majority of cases is made postoperatively at histological examination. The clinical manifestations of PC are primarily due to the excessive secretion of PTH by the tumor rather than spread to local or distant organs. En bloc resection of the parathyroid tumor represents the initial mainstay treatment of patients with PC. Multiple surgical procedures may be required, although surgical morbidity should be taken into account. A 5- and 10-year survival between 77-100 and 49-91%, respectively, has been reported. When the tumor is no more resectable, medical treatment of hypercalcemia has a pivotal role in the management of these patients.
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PMID:Parathyroid Carcinoma. 3064 23

Parathyroid carcinoma (PC) is a rare endocrine malignancy with poor outcomes. Although some mutations such as CDC73 have been found in patients, the molecular mechanism of PC still needs extensive data to clarify. Whole-genome sequencing (WGS) was performed with frozen samples from 23 PC patients. Peripheral leukocytes were collected from 14 patients and served as controls. Somatic and germline gene alterations, copy number abnormalities and structural variants were detected. Inactivating CDC73 mutations were identified in 39.1% of patients, but only one germline inactivating mutation was found. Other cancer-related mutations identified in more than one case were MAF (2/23), NEB (6/23), NCOR1 (2/23), TTK (2/23), GRIN3A (4/23), TRIO (2/23), MAP1B (2/23), TJP2 (2/23) and FAM20A (2/23). In the seven wild-type CDC73 samples, the mutated genes were enriched in pathways involving antigen presentation, allograft rejection or autoimmune disease. More copy number variants were found in patients with cancer recurrence (P = .006) and CDC73 mutations (P = .022) than in those without these characteristics. PIK3CA loss was found in one sample, which also harboured a CDC73 mutation. Gene alterations in the PI3K/AKT/mTOR pathway were found in 78.3% (18/23) of tumours. The most prominent cancer-predisposing mutations were PDE4DIP (15/23), MAP3K1 (13/23) and CDC42EP1 (10/23). In conclusion, the PI3K/AKT/mTOR pathway may be pivotal in PC. CDC73 mutation correlated with an increased mutational burden and tumour relapse. PC patients with wild-type CDC73 harboured mutations relevant to antigen presentation and autoimmune diseases. A molecular classification based on the CDC73 mutation may help to manage follow-up and therapy for PC patients.
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PMID:The genomic profile of parathyroid carcinoma based on whole-genome sequencing. 3257 88