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1.
Nat Commun ; 11(1): 3200, 2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32581239

RESUMO

mTOR activation is essential and sufficient to cause polycystic kidneys in Tuberous Sclerosis Complex (TSC) and other genetic disorders. In disease models, a sharp increase of proliferation and cyst formation correlates with a dramatic loss of oriented cell division (OCD). We find that OCD distortion is intrinsically due to S6 kinase 1 (S6K1) activation. The concomitant loss of S6K1 in Tsc1-mutant mice restores OCD but does not decrease hyperproliferation, leading to non-cystic harmonious hyper growth of kidneys. Mass spectrometry-based phosphoproteomics for S6K1 substrates revealed Afadin, a known component of cell-cell junctions required to couple intercellular adhesions and cortical cues to spindle orientation. Afadin is directly phosphorylated by S6K1 and abnormally decorates the apical surface of Tsc1-mutant cells with E-cadherin and α-catenin. Our data reveal that S6K1 hyperactivity alters centrosome positioning in mitotic cells, affecting oriented cell division and promoting kidney cysts in conditions of mTOR hyperactivity.


Assuntos
Divisão Celular , Cinesina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Miosinas/metabolismo , Doenças Renais Policísticas/patologia , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Animais , Linhagem Celular , Cinesina/genética , Camundongos , Camundongos Mutantes , Mutação , Miosinas/genética , Fosforilação , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Transdução de Sinais , Esclerose Tuberosa/genética , Esclerose Tuberosa/metabolismo , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo
2.
Gene ; 753: 144815, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32479982

RESUMO

Lymphedema are characterized by interstitial edema leading to swelling of extremities. They can be divided into primary and secondary lymphedema. Developmental abnormalities of the lymphatic system are responsible for the primary form of lymphedema. The secondary form of lymphedema is caused by damage of the lymphatic system due to external factors. Lymphedema can rarely be observed in patients with tuberous sclerosis complex (TSC), which is a neurocutaneous syndrome caused by pathogenic variants in the genes TSC1 or TSC2. Patients with TSC usually present with neurological manifestations and the development of multiple benign tumors of ectodermal origin. Typical onset for several symptoms is during the first year of life and in some cases lesions can be detected prenatally. Epilepsy is one of the most common manifestations, affecting up to 90% of TSC patients, and is associated with developmental delay. Early pharmacotherapy improves long term patient outcome. Trio exome sequencing was performed in a 3 weeks old girl with congenital lymphedema of the right lower extremity. Using a filter for de novo variants, the heterozygous missense variant c.2524C>T, p.(Gln842Ter) in TSC1 (NM_000368.4) could be identified. After the first onset of infantile spams at age 7 months treatment with vigabatrin was started immediately. We propose to include TSC1 and TSC2 analysis in the diagnostic work-up of patients with (isolated) congenital lymphedema as early diagnosis facilitates consequent treatment strategies potentially improving the prognosis of TSC patients.


Assuntos
Linfedema/genética , Esclerose Tuberosa/genética , Esclerose Tuberosa/patologia , Deficiências do Desenvolvimento/complicações , Epilepsia/genética , Feminino , Humanos , Lactente , Linfedema/complicações , Linfedema/patologia , Mutação de Sentido Incorreto/genética , Prognóstico , Esclerose Tuberosa/complicações , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Sequenciamento Completo do Exoma
3.
Nat Med ; 26(6): 909-918, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32472114

RESUMO

PD-1 blockade has transformed the management of advanced clear cell renal cell carcinoma (ccRCC), but the drivers and resistors of the PD-1 response remain incompletely elucidated. Here, we analyzed 592 tumors from patients with advanced ccRCC enrolled in prospective clinical trials of treatment with PD-1 blockade by whole-exome and RNA sequencing, integrated with immunofluorescence analysis, to uncover the immunogenomic determinants of the therapeutic response. Although conventional genomic markers (such as tumor mutation burden and neoantigen load) and the degree of CD8+ T cell infiltration were not associated with clinical response, we discovered numerous chromosomal alterations associated with response or resistance to PD-1 blockade. These advanced ccRCC tumors were highly CD8+ T cell infiltrated, with only 27% having a non-infiltrated phenotype. Our analysis revealed that infiltrated tumors are depleted of favorable PBRM1 mutations and enriched for unfavorable chromosomal losses of 9p21.3, as compared with non-infiltrated tumors, demonstrating how the potential interplay of immunophenotypes with somatic alterations impacts therapeutic efficacy.


Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Nivolumabe/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Apresentação do Antígeno/genética , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/patologia , Deleção Cromossômica , Cromossomos Humanos Par 6 , Cromossomos Humanos Par 9/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Proteínas de Ligação a DNA/genética , Feminino , Imunofluorescência , Deleção de Genes , Genômica , Antígenos de Histocompatibilidade Classe II/genética , Histona Desmetilases/genética , Histona-Lisina N-Metiltransferase/genética , Humanos , Neoplasias Renais/genética , Neoplasias Renais/imunologia , Neoplasias Renais/patologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/patologia , Masculino , Pessoa de Meia-Idade , Mutação , PTEN Fosfo-Hidrolase/genética , Prognóstico , Complexo de Endopeptidases do Proteassoma/genética , Análise de Sequência de RNA , Serina-Treonina Quinases TOR/genética , Fatores de Transcrição/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Proteína Supressora de Tumor Von Hippel-Lindau/genética , Sequenciamento Completo do Exoma
4.
Expert Opin Pharmacother ; 21(11): 1329-1336, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32338549

RESUMO

INTRODUCTION: Subependymal ependymal giant cell astrocytomas (SEGAs) occur almost exclusively in the setting of tuberous sclerosis (TSC). They are low-grade gliomas which typically produce clinical symptoms through either mass effect or hydrocephalus. As do other manifestations of tuberous sclerosis, these lesions result from mutations in either the TSC1 or the TSC2 gene. These mutations cause hyperactivation of the mechanistic target of rapamycin (mTOR). In view of their tendency to grow slowly, clinical symptoms usually only occur when the tumors reach a considerable size. Therapy can involve surgical resection, cerebrospinal fluid diversion, or medical therapy with an mTOR inhibitor. AREAS COVERED: Herein, the authors discuss the diagnosis, symptoms, and practical management of SEGAs as well as providing their expert opinion. EXPERT OPINION: mTOR inhibitors have largely replaced surgery as the primary modality for the management of SEGAs. Surgical treatment is largely limited to tumors that present with acute hydrocephalus and increased intracranial pressure. Patients with TSC should undergo periodic screening with CT or preferably MRI scans of the brain from childhood to approximately age 25 to identify SEGAs which require treatment. In addition to avoiding potential morbidity associated with surgical resection, mTOR inhibitors have the potential to improve the clinical status of tuberous sclerosis patients generally.


Assuntos
Antineoplásicos/uso terapêutico , Astrocitoma/tratamento farmacológico , Neoplasias Encefálicas/tratamento farmacológico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Esclerose Tuberosa/tratamento farmacológico , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Astrocitoma/etiologia , Astrocitoma/metabolismo , Astrocitoma/patologia , Neoplasias Encefálicas/etiologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Criança , Humanos , Mutação , Esclerose Tuberosa/complicações , Esclerose Tuberosa/metabolismo , Esclerose Tuberosa/patologia , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética
5.
Am J Surg Pathol ; 44(7): 943-954, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32091432

RESUMO

Eosinophilic renal neoplasms have a wide spectrum of histologic presentations, and several studies have demonstrated a subtype of renal cell carcinomas (RCCs) associated with the tuberous sclerosis complex (TSC)/mammalian target of rapamycin pathway. A review of our institutional archives led to the identification of 18 cases of renal eosinophilic tumors with unusual morphology. Immunohistochemical analysis demonstrated that these could be separated into 3 groups: group 1 had solid architecture and morphology similar to chromophobe RCC but was negative for CK20 and vimentin, and had weak focal staining for CK7 and P504S; group 2 had solid architecture and morphology similar to either renal oncocytoma or chromophobe RCC, eosinophilic variant and had diffuse staining of CK7 and P504S, absent to weak staining of CK20, and negative staining for vimentin; and group 3 had solid, cystic and papillary architecture and was negative for CK7, except for 1 case, along with moderate to strong staining of CK20, P504S, and vimentin. The cases were then sent for next-generation sequencing to determine whether molecular pathogenic variants were present. In group 1, all 3 cases had mutations in TSC2. In group 2, pathogenic variants were identified in 3 genes: TSC1, TSC2, and MTOR. In group 3, genetic alterations and pathogenic variants were identified in TSC1 and TSC2. Our results support TSC/MTOR-associated neoplasms as a distinct group that exhibits heterogenous morphology and immunohistochemical staining.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Renais/diagnóstico , Eosinófilos/patologia , Neoplasias Renais/diagnóstico , Serina-Treonina Quinases TOR/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Adolescente , Adulto , Idoso , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Eosinofilia/etiologia , Eosinofilia/patologia , Feminino , Seguimentos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imuno-Histoquímica , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Prognóstico , Estudos Retrospectivos , Adulto Jovem
6.
Int J Mol Sci ; 21(3)2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32013265

RESUMO

Gastric cancer (GC) is one of the most common and lethal gastrointestinal malignancies worldwide. Many studies have shown that development of GC and other malignancies is mainly driven by alterations of cellular signaling pathways. MicroRNAs (miRNAs) are small noncoding molecules that function as tumor-suppressors or oncogenes, playing an essential role in a variety of fundamental biological processes. In order to understand the functional relevance of miRNA dysregulation, studies analyzing their target genes are of major importance. Here, we chose to analyze two miRNAs, miR-20b and miR-451a, shown to be deregulated in many different malignancies, including GC. Deregulated expression of miR-20b and miR-451a was determined in GC cell lines and the INS-GAS mouse model. Using Western Blot and luciferase reporter assay we determined that miR-20b directly regulates expression of PTEN and TXNIP, and miR-451a: CAV1 and TSC1. Loss-of-function experiments revealed that down-regulation of miR-20b and up-regulation of miR-451a expression exhibits an anti-tumor effect in vitro (miR-20b: reduced viability, colony formation, increased apoptosis rate, and miR-451a: reduced colony forming ability). To summarize, the present study identified that expression of miR-20b and miR-451a are deregulated in vitro and in vivo and have a tumor suppressive role in GC through regulation of the PI3K/AKT/mTOR signaling pathway.


Assuntos
MicroRNAs/metabolismo , Transdução de Sinais , Neoplasias Gástricas/patologia , Animais , Antagomirs/metabolismo , Apoptose , Proteínas de Transporte/metabolismo , Caveolina 1/genética , Caveolina 1/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo
7.
J Clin Invest ; 130(3): 1233-1251, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32039915

RESUMO

Smooth muscle cell (SMC) proliferation has been thought to limit the progression of thoracic aortic aneurysm and dissection (TAAD) because loss of medial cells associates with advanced disease. We investigated effects of SMC proliferation in the aortic media by conditional disruption of Tsc1, which hyperactivates mTOR complex 1. Consequent SMC hyperplasia led to progressive medial degeneration and TAAD. In addition to diminished contractile and synthetic functions, fate-mapped SMCs displayed increased proteolysis, endocytosis, phagocytosis, and lysosomal clearance of extracellular matrix and apoptotic cells. SMCs acquired a limited repertoire of macrophage markers and functions via biogenesis of degradative organelles through an mTOR/ß-catenin/MITF-dependent pathway, but were distinguishable from conventional macrophages by an absence of hematopoietic lineage markers and certain immune effectors even in the context of hyperlipidemia. Similar mTOR activation and induction of a degradative SMC phenotype in a model of mild TAAD due to Fbn1 mutation greatly worsened disease with near-uniform lethality. The finding of increased lysosomal markers in medial SMCs from clinical TAAD specimens with hyperplasia and matrix degradation further supports the concept that proliferation of degradative SMCs within the media causes aortic disease, thus identifying mTOR-dependent phenotypic modulation as a therapeutic target for combating TAAD.


Assuntos
Aneurisma Dissecante/enzimologia , Aorta/enzimologia , Aneurisma da Aorta Torácica/enzimologia , Miócitos de Músculo Liso/enzimologia , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Aneurisma Dissecante/genética , Aneurisma Dissecante/patologia , Animais , Aorta/patologia , Aneurisma da Aorta Torácica/genética , Aneurisma da Aorta Torácica/patologia , Modelos Animais de Doenças , Lisossomos/enzimologia , Lisossomos/genética , Lisossomos/patologia , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Knockout para ApoE , Fator de Transcrição Associado à Microftalmia/genética , Fator de Transcrição Associado à Microftalmia/metabolismo , Miócitos de Músculo Liso/patologia , Serina-Treonina Quinases TOR/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
8.
PLoS One ; 15(2): e0228894, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32078667

RESUMO

Lymphangioleiomyomatosis (LAM) is a devastating lung disease caused by inactivating gene mutations in either TSC1 or TSC2 that result in hyperactivation of the mechanistic target of rapamycin complex 1 (mTORC1). As LAM occurs predominantly in women during their reproductive age and is exacerbated by pregnancy, the female hormonal environment, and in particular estrogen, is implicated in LAM pathogenesis and progression. However, detailed underlying molecular mechanisms are not well understood. In this study, utilizing human pulmonary LAM specimens and cell culture models of TSC2-deficient LAM patient-derived and rat uterine leiomyoma-derived cells, we tested the hypothesis that estrogen promotes the growth of mTORC1-hyperactive cells through pyruvate kinase M2 (PKM2). Estrogen increased the phosphorylation of PKM2 at Ser37 and induced the nuclear translocation of phospho-PKM2. The estrogen receptor antagonist Faslodex reversed these effects. Restoration of TSC2 inhibited the phosphorylation of PKM2 in an mTORC1 inhibitor-insensitive manner. Finally, accumulation of phosphorylated PKM2 was evident in pulmonary nodule from LAM patients. Together, our data suggest that female predominance of LAM might be at least in part attributed to estrogen stimulation of PKM2-mediated cellular metabolic alterations. Targeting metabolic regulators of PKM2 might have therapeutic benefits for women with LAM and other female-specific neoplasms.


Assuntos
Estrogênios/metabolismo , Piruvato Quinase/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/genética , Animais , Linhagem Celular Tumoral , Estrogênios/fisiologia , Feminino , Humanos , Pulmão/patologia , Neoplasias Pulmonares/patologia , Linfangioleiomiomatose/genética , Linfangioleiomiomatose/fisiopatologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Fosforilação , Piruvato Quinase/fisiologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo , Proteínas Supressoras de Tumor/genética
9.
Proc Natl Acad Sci U S A ; 117(3): 1524-1532, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31919282

RESUMO

Loss of the tumor suppressor tuberous sclerosis complex 1 (Tsc1) in the liver promotes gluconeogenesis and glucose intolerance. We asked whether this could be attributed to aberrant expression of small RNAs. We performed small-RNA sequencing on liver of Tsc1-knockout mice, and found that miRNAs of the delta-like homolog 1 (Dlk1)-deiodinase iodothyronine type III (Dio3) locus are up-regulated in an mTORC1-dependent manner. Sustained mTORC1 signaling during development prevented CpG methylation and silencing of the Dlk1-Dio3 locus, thereby increasing miRNA transcription. Deletion of miRNAs encoded by the Dlk1-Dio3 locus reduced gluconeogenesis, glucose intolerance, and fasting blood glucose levels. Thus, miRNAs contribute to the metabolic effects observed upon loss of TSC1 and hyperactivation of mTORC1 in the liver. Furthermore, we show that miRNA is a downstream effector of hyperactive mTORC1 signaling.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Gluconeogênese/fisiologia , Iodeto Peroxidase/metabolismo , MicroRNAs/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , Regulação para Cima , Animais , Proteínas de Ligação ao Cálcio/genética , Loci Gênicos , Impressão Genômica , Gluconeogênese/genética , Iodeto Peroxidase/genética , Fígado/metabolismo , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Knockout , MicroRNAs/genética , Análise de Sequência , Transdução de Sinais , Transcriptoma , Proteína 1 do Complexo Esclerose Tuberosa/genética
10.
J Med Chem ; 63(3): 1068-1083, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-31955578

RESUMO

Recent clinical evaluation of everolimus for seizure reduction in patients with tuberous sclerosis complex (TSC), a disease with overactivated mechanistic target of rapamycin (mTOR) signaling, has demonstrated the therapeutic value of mTOR inhibitors for central nervous system (CNS) indications. Given that everolimus is an incomplete inhibitor of the mTOR function, we sought to develop a new mTOR inhibitor that has improved properties and is suitable for CNS disorders. Starting from an in-house purine-based compound, optimization of the physicochemical properties of a thiazolopyrimidine series led to the discovery of the small molecule 7, a potent and selective brain-penetrant ATP-competitive mTOR inhibitor. In neuronal cell-based models of mTOR hyperactivity, 7 corrected the mTOR pathway activity and the resulting neuronal overgrowth phenotype. The new mTOR inhibitor 7 showed good brain exposure and significantly improved the survival rate of mice with neuronal-specific ablation of the Tsc1 gene. These results demonstrate the potential utility of this tool compound to test therapeutic hypotheses that depend on mTOR hyperactivity in the CNS.


Assuntos
Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Convulsões/tratamento farmacológico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Tiazóis/uso terapêutico , Animais , Anticonvulsivantes/metabolismo , Anticonvulsivantes/farmacocinética , Anticonvulsivantes/uso terapêutico , Sítios de Ligação , Encéfalo/efeitos dos fármacos , Descoberta de Drogas , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/efeitos dos fármacos , Ligação Proteica , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacocinética , Pirimidinas/metabolismo , Pirimidinas/farmacocinética , Ratos , Serina-Treonina Quinases TOR/química , Serina-Treonina Quinases TOR/metabolismo , Tiazóis/metabolismo , Tiazóis/farmacocinética , Proteína 1 do Complexo Esclerose Tuberosa/genética
11.
Zhonghua Yi Xue Za Zhi ; 100(2): 136-140, 2020 Jan 14.
Artigo em Chinês | MEDLINE | ID: mdl-31937054

RESUMO

Objective: Tuberous sclerosis complex (TSC) is a multi-system disease with TSC1 and TSC2 genes as the pathogenic genes. The purpose of our study was to analyze the gene mutation in patients with TSC with epilepsy as the main clinical manifestation. The relationship between genotype and phenotype, scalp EEG in patients was analyzed. Methods: The peripheral blood was extracted from 43 patients and their families. TSC gene was detected by second-generation sequencing. Long-term video EEG monitoring and MRI examination were performed to determine the onset area, seizure type and location of nodules. Results: 39 patients had TSC gene mutation, 4 patients did not detect the gene mutation.11 had TSC1 mutations and 28 had TSC2 mutations. 22 mutations were de novo. Patients with TSC2 mutations had earlier seizure and more nodules than patients with TSC1 mutations, but no significant difference in intelligence and spasm were observed. 28 patients had focal origin of scalp EEG, of which 85.7% of TSC2 mutations patients had focal origin. Conclusions: Patients of TSC2 mutations always has an early onset age. Although MRI shows multiple nodules, the onset of EEG is mainly focal origin.


Assuntos
Esclerose Tuberosa , Análise Mutacional de DNA , Eletroencefalografia , Genótipo , Humanos , Mutação , Fenótipo , Proteína 1 do Complexo Esclerose Tuberosa , Proteína 2 do Complexo Esclerose Tuberosa
12.
Nat Commun ; 11(1): 37, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31896747

RESUMO

Nutrients are absorbed solely by the intestinal villi. Aging of this organ causes malabsorption and associated illnesses, yet its aging mechanisms remain unclear. Here, we show that aging-caused intestinal villus structural and functional decline is regulated by mTORC1, a sensor of nutrients and growth factors, which is highly activated in intestinal stem and progenitor cells in geriatric mice. These aging phenotypes are recapitulated in intestinal stem cell-specific Tsc1 knockout mice. Mechanistically, mTORC1 activation increases protein synthesis of MKK6 and augments activation of the p38 MAPK-p53 pathway, leading to decreases in the number and activity of intestinal stem cells as well as villus size and density. Targeting p38 MAPK or p53 prevents or rescues ISC and villus aging and nutrient absorption defects. These findings reveal that mTORC1 drives aging by augmenting a prominent stress response pathway in gut stem cells and identify p38 MAPK as an anti-aging target downstream of mTORC1.


Assuntos
Intestinos/citologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Células-Tronco/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Envelhecimento , Animais , Proliferação de Células , Senescência Celular , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Mucosa Intestinal/citologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Intestinos/fisiologia , MAP Quinase Quinase 6/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Camundongos Knockout , Proteína Quinase 14 Ativada por Mitógeno/genética , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Receptores Acoplados a Proteínas-G/genética , Transdução de Sinais , Sirolimo/farmacologia , Células-Tronco/citologia , Tamoxifeno/farmacologia , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo
13.
Cancer Sci ; 111(4): 1146-1155, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31975504

RESUMO

Although several studies have reported that microRNA (miR)-92b-3p is involved in various cellular processes related to carcinogenesis, its physiological role in clear cell renal cell carcinoma (ccRCC) remains unclear. To clarify the role of miR-92b-3p in ccRCC, we compared miR-92b-3p expression levels in ccRCC tissues and adjacent normal renal tissues. Significant upregulation of miR-92b-3p was observed in ccRCC tissues. Overexpression of miR-92b-3p using a miRNA mimic promoted proliferation, migration, and invasion activities of ACHN cells. Functional inhibition of miR-92b-3p by a hairpin miRNA inhibitor suppressed Caki-2 cell growth and invasion activities in vitro. Mechanistically, it was found that miR-92b-3p directly targeted the TSC1 gene, a known upstream regulator of mTOR. Overexpression of miR-92b-3p decreased the protein expression of TSC1 and enhanced the downstream phosphorylation of p70S6 kinase, suggesting that the mTOR signaling pathway was activated by miR-92b-3p in RCC cells. Importantly, a multivariate Cox proportion hazard model, based on TNM staging and high levels of miR-92b-3p, revealed that miR-92b-3p expression (high vs. low hazard ratio, 2.86; 95% confidence interval, 1.20-6.83; P = .018) was a significant prognostic factor for overall survival of ccRCC patients with surgical management. Taken together, miR-92b-3p was found to act as an oncomiR, promoting cell proliferation by downregulating TSC1 in ccRCC.


Assuntos
Carcinogênese/genética , Carcinoma de Células Renais/genética , MicroRNAs/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/patologia , Proliferação de Células/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Rim/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico
14.
Int J Cancer ; 146(5): 1435-1444, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31335987

RESUMO

The mammalian target of rapamycin (mTOR) pathway inhibitors are key drugs for the treatment of many tumor types, however, there are no predictive biomarkers in clinical use. Here, we performed a molecular and immunohistochemical characterization of key mTOR pathway components in a series of 105 renal cell carcinoma patients treated with rapalogs, aimed at identifying markers of treatment response. Mutational analysis in MTOR, TSC1 and TSC2 was performed through targeted next-generation sequencing (NGS), and immunohistochemistry (IHC) was performed for PTEN, pAKT, pS6K1, pS6 and p21. Among patients with NGS data, 11 of 87 (13%) had mTOR pathway mutations (8 in MTOR, 1 in TSC1 and 2 in TSC2). When comparing the molecular data to the response of the patients, we found that partial response was more frequent in cases with mTOR pathway mutations than in those without mutations (odds ratio [OR] = 0.08, 95% confidence interval [CI] = 0.008-0.79, p = 0.030 univariate; p = 0.038 multivariable). Regarding IHC, negative PTEN staining was detected in 58% of the tumors, and it was more frequent in rapalog responder patients (OR = 0.24, 95% CI = 0.065-0.86, p = 0.029 univariate; p = 0.029 multivariable). Mutations and PTEN IHC were not mutually exclusive events and its combination improved response prediction (OR = 0.16, 95% CI = 0.04-0.62, p = 0.008 univariate; p = 0.013 multivariable). The staining of other proteins did not show and association with response and no association with PFS was observed in unselected patients. In conclusion, our findings suggest that mTOR pathway mutations, negative PTEN IHC and their combination are potential markers of rapalog response.


Assuntos
Antineoplásicos/farmacologia , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Renais/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/mortalidade , Análise Mutacional de DNA , Everolimo/farmacologia , Everolimo/uso terapêutico , Feminino , Seguimentos , Humanos , Rim/patologia , Neoplasias Renais/genética , Neoplasias Renais/mortalidade , Masculino , Pessoa de Meia-Idade , Mutação , PTEN Fosfo-Hidrolase/metabolismo , Prognóstico , Intervalo Livre de Progressão , Estudos Prospectivos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética
15.
Am J Pathol ; 190(1): 158-175, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31733185

RESUMO

Chronic alcohol consumption induces adipose tissue atrophy. However, the mechanisms for how alcohol induces lipodystrophy and its impact on liver steatosis and injury are not fully elucidated. Autophagy is a highly conserved lysosomal degradation pathway, which regulates cellular homeostasis. Mice with autophagy deficiency in adipose tissue have impaired adipogenesis. However, whether autophagy plays a role in alcohol-induced adipose atrophy and how altered adipocyte autophagy contributes to alcohol-induced liver injury remain unclear. To determine the role of adipose autophagy and mechanistic target of rapamycin (mTOR) in alcohol-induced adipose and liver pathogenesis, we generated adipocyte-specific Atg5 knockout (KO), adipocyte-specific mTOR KO, adipocyte-specific Raptor KO, and adipocyte-specific tuberous sclerosis complex 1 KO mice by crossing floxed mice with Adipoq-Cre. The KO mice and their matched wild-type mice were challenged with chronic-plus-binge alcohol mouse model. Chronic-plus-binge alcohol induced adipose atrophy with increased autophagy and decreased Akt/mTOR signaling in epididymal adipose tissue in wild-type mice. Adipocyte-specific Raptor KO mice experienced exacerbated alcohol-induced steatosis, but neither adipocyte-specific mTOR nor adipocyte-specific tuberous sclerosis complex 1 KO mice exhibited similar detrimental effects. Adipocyte-specific Atg5 KO mice had increased circulating levels of fibroblast growth factor 21 and adiponectin and were resistant to alcohol-induced adipose atrophy and liver injury. In conclusion, autophagy deficiency in adipose tissue leads to reduced sensitivity to alcohol-induced adipose atrophy, which ameliorates alcohol-induced liver injury in mice.


Assuntos
Tecido Adiposo/patologia , Atrofia/patologia , Autofagia , Doença Hepática Crônica Induzida por Substâncias e Drogas/patologia , Etanol/toxicidade , Serina-Treonina Quinases TOR/fisiologia , Animais , Anti-Infecciosos Locais/toxicidade , Atrofia/etiologia , Atrofia/metabolismo , Proteína 5 Relacionada à Autofagia/fisiologia , Doença Hepática Crônica Induzida por Substâncias e Drogas/etiologia , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Regulatória Associada a mTOR/fisiologia , Transdução de Sinais , Proteína 1 do Complexo Esclerose Tuberosa/fisiologia
16.
Am J Surg Pathol ; 44(5): 571-581, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31850909

RESUMO

Renal cell carcinoma with (angio) leiomyomatous stroma (RCCLMS) is included as a provisional entity in the 2016 World Health Organization (WHO) classification of renal epithelial neoplasia; however, debate remains whether it represents a distinct entity or a heterogenous group of renal cell carcinomas (RCCs) with overlapping morphology. Also, its relationship to similar tumors occurring in the setting of tuberous sclerosis complex (TSC) is not fully addressed. We analyzed the clinicopathologic, immunohistochemical, and molecular characteristics of 23 sporadic RCCs associated with smooth muscle stroma and classified them into 2 groups, independent of molecular results: (1) RCCLMS (n=18) and (2) clear cell renal cell carcinoma (CCRCC) (n=5). The classification of a case as "RCCLMS" was based on morphologic comparison with 5 "index" RCCs from 3 patients with TSC showing similar features and the presence of diffuse CK7 expression. To investigate mutational and copy number alterations, a 170-gene solid tumor panel was utilized to sequence 14 RCCLMSs and control of 5 CCRCCs. Also, 4 RCCLMSs, suspicious for chromosome 8 monosomy, were further evaluated by a broader 479 gene sequencing panel that included ELOC (also referred to as TCEB1). Clinical information and follow-up data were obtained from electronic medical records. The mean age of patients with RCCLMS was 52 years (range, 33 to 69) with male:female ratio of 1:2. Macroscopically, all tumors were solitary and predominantly (82%) tan/red, circumscribed, and solid. The average tumor size was 2.3 cm (range, 1.1 to 4.5). Microscopically, the distinctive feature included tumor nodules of elongated and frequently branching tubules lined by cells with voluminous clear to mildly eosinophilic cytoplasm (100%), separated by focal to prominent smooth muscle stroma. Additional frequently identified features included: biphasic pattern of collapsed acini surrounding tubules with voluminous cytoplasm (50%), focal papillary architecture (39%), peritumoral lymphoid aggregates (39%), and hemosiderin-laden macrophages (33%). All 11 (100%) RCCLMSs with available staging information were pT1; 78% were WHO/International Society of Urologic Pathology (ISUP) grade 2 and 22% grade 3. Immunophenotypically, RCCLMSs were characterized by diffuse CK7, CAM5.2 and CD10 reactivity (100%). All patients with available follow-up (n=10) were alive and without disease progression after a mean and median follow-up of 25.2 (range: 1 to 58) and 25 months, respectively. The molecular results showed recurrent mutations in all RCCLMS: TSC1 (4), TSC2 (4), MTOR (6), and/or ELOC (2). Five control CCRCCs demonstrated primary alterations in VHL gene, while all 14 RCCLMS cases tested had intact VHL gene. Of 2 RCCLMSs with confirmed monosomy 8, 1 showed a hotspot ELOC mutation without TSC/MTOR mutations, and 1 showed a previously undescribed 3-bp in-frame ELOC deletion, along with a truncating TSC1 mutation. In conclusion, RCCLMS, as defined herein, harbors recurrent mutations of TSC1/TSC2, MTOR, and/or ELOC, consistent with hyperactive MTOR complex. Our findings argue that these tumors represent the sporadic counterpart to morphologically identical tumors occurring in TSC patients. Finally, the data support that RCCLMS is a novel subtype of RCC with unique morphologic, immunohistochemical, and molecular characteristics that is distinct from CCRCC and clear cell-papillary RCC.


Assuntos
Angiomioma/genética , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/genética , Elonguina/genética , Neoplasias Renais/genética , Mutação , Serina-Treonina Quinases TOR/genética , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Adulto , Idoso , Alberta , Angiomioma/patologia , Carcinoma de Células Renais/classificação , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/terapia , Feminino , Predisposição Genética para Doença , Humanos , Neoplasias Renais/classificação , Neoplasias Renais/patologia , Neoplasias Renais/terapia , Masculino , Pessoa de Meia-Idade , Ohio , Fenótipo , Intervalo Livre de Progressão , Células Estromais/patologia , Terminologia como Assunto
17.
Genet Test Mol Biomarkers ; 24(1): 1-5, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31855466

RESUMO

Objective: Tuberous sclerosis complex (TSC) is a multisystem disease. Variants in the TSC1 and TSC2 genes have been reported to be associated with TSC and are considered pathogenic. The purpose of this study was to determine the genetic mutations and expression patterns of TSC1 and TSC2 in 21 Chinese patients suffering from TSC who were clinically characterized by epilepsy. Methods: Peripheral blood samples were taken from 21 patients, their parents, and other family members. Their TSC1 and TSC2 genes were sequenced through next-generation sequencing to identify all variants. Results: We identified variants in 17/21 patients in either their TSC1 or TSC2 genes: 6 patients had TSC1 mutations and 11 had TSC2 mutations. There were 13 spontaneous mutations, and 3 that had been inherited from a parent. The mutations were classified by types: there were three missense mutations, five frameshift mutations, two splice site mutations, four nonsense mutations, two single codon deletions resulting the loss of an amino acid, and one large fragment deletion. Six of the mutations have not been previously reported. Conclusion: The genotypic analysis of Chinese TSC patients who are clinically characterized by epilepsy can potentially be useful for genetic counseling and prenatal diagnoses for patients and their families.


Assuntos
Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Esclerose Tuberosa/genética , Adulto , Grupo com Ancestrais do Continente Asiático/genética , China/epidemiologia , Códon sem Sentido , Análise Mutacional de DNA/métodos , Epilepsia/genética , Éxons , Família , Feminino , Mutação da Fase de Leitura , Humanos , Masculino , Mutação , Mutação de Sentido Incorreto , Linhagem , Transcriptoma/genética , Esclerose Tuberosa/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo , Proteínas Supressoras de Tumor/genética
18.
PLoS One ; 14(12): e0226400, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31856217

RESUMO

The aim of our study was to elucidate the landscapes of genetic alterations of TSC1 and TSC2 as well as other possible non-TSC1/2 in Lymphangioleiomyomatosis (LAM) patients. Sixty-one Chinese LAM patients' clinical information was collected. Tumor biopsies and matched leukocytes from these patients were retrospectively analyzed by next generation sequencing (NGS), chromosomal microarray analysis (CMA), and multiplex ligation-dependent probe amplification (MLPA). Eighty-six TSC1/2 variants were identified in 46 of the 61 LAM patients (75.4%) in which TSC2 and TSC1 variants were 88.37% and 11.63% respectively. The 86 variants are composed of (i) 52 single nucleotide variants (SNVs) (including 30 novel variants), (ii) 23 indels (including 21deletions, and 2 insertions), (iii) a germline duplication of exon 31-42 of TSC2, (iv) a 2.68 Mb somatic duplication containing TSC2, and (v) 9 regions with copy-neutral loss of heterogeneity (CN-LOHs) present only in the LAM patients with single TSC1/2 mutations. Sixty-one non-TSC1/2 variants in 31 genes were identified in 37 LAM patients. Combined applications of different techniques are necessary to achieve maximal detection rate of TSC1/2 variants in LAM patients. Thirty novel TSC1/2 variants expands the spectrum of TSC1/2 in LAM patients. Identification of 61 non-TSC1/2 variants suggests that alternative genes might have contributed to the initiation and progression of LAM.


Assuntos
Linfangioleiomiomatose/genética , Mutação , Proteína 1 do Complexo Esclerose Tuberosa/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Adulto , China , Variações do Número de Cópias de DNA , Feminino , Humanos , Linfangioleiomiomatose/diagnóstico por imagem , Linfangioleiomiomatose/patologia , Polimorfismo de Nucleotídeo Único
19.
Nat Commun ; 10(1): 5426, 2019 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-31780742

RESUMO

Tuberous Sclerosis Complex (TSC) is a neurodevelopmental disorder caused by mutations in TSC1 or TSC2, which encode proteins that negatively regulate mTOR complex 1 (mTORC1). TSC is associated with significant cognitive, psychiatric, and behavioral problems, collectively termed TSC-Associated Neuropsychiatric Disorders (TAND), and the cell types responsible for these manifestations are largely unknown. Here we use cell type-specific Tsc1 deletion to test whether dopamine neurons, which modulate cognitive, motivational, and affective behaviors, are involved in TAND. We show that loss of Tsc1 and constitutive activation of mTORC1 in dopamine neurons causes somatodendritic hypertrophy, reduces intrinsic excitability, alters axon terminal structure, and impairs striatal dopamine release. These perturbations lead to a selective deficit in cognitive flexibility, preventable by genetic reduction of the mTOR-binding protein Raptor. Our results establish a critical role for Tsc1-mTORC1 signaling in setting the functional properties of dopamine neurons, and indicate that dopaminergic dysfunction may contribute to cognitive inflexibility in TSC.


Assuntos
Cognição/fisiologia , Corpo Estriado/metabolismo , Dopamina/metabolismo , Neurônios Dopaminérgicos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/genética , Animais , Axônios/patologia , Comportamento Animal , Corpo Celular/patologia , Corpo Estriado/patologia , Neurônios Dopaminérgicos/patologia , Técnicas de Inativação de Genes , Hipertrofia , Camundongos , Motivação , Plasticidade Neuronal/genética , Transdução de Sinais , Esclerose Tuberosa/genética , Esclerose Tuberosa/psicologia , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo
20.
Int J Mol Sci ; 20(22)2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703252

RESUMO

Cellular homeostasis is controlled by an evolutionary conserved cellular digestive process called autophagy. This mechanism is tightly regulated by the two sensor elements called mTORC1 and AMPK. mTORC1 is one of the master regulators of proteostasis, while AMPK maintains cellular energy homeostasis. AMPK is able to promote autophagy by phosphorylating ULK1, the key inducer of autophagosome formation, while mTORC1 downregulates the self-eating process via ULK1 under nutrient rich conditions. We claim that the feedback loops of the AMPK-mTORC1-ULK1 regulatory triangle guarantee the appropriate response mechanism when nutrient and/or energy supply changes. In our opinion, there is an essential double negative feedback loop between mTORC1 and AMPK. Namely, not only does AMPK downregulate mTORC1, but mTORC1 also inhibits AMPK and this inhibition is required to keep AMPK inactive at physiological conditions. The aim of the present study was to explore the dynamical characteristic of AMPK regulation upon various cellular stress events. We approached our scientific analysis from a systems biology perspective by incorporating both theoretical and molecular biological techniques. In this study, we confirmed that AMPK is essential to promote autophagy, but is not sufficient to maintain it. AMPK activation is followed by ULK1 induction, where protein has a key role in keeping autophagy active. ULK1-controlled autophagy is always preceded by AMPK activation. With both ULK1 depletion and mTORC1 hyper-activation (i.e., TSC1/2 downregulation), we demonstrate that a double negative feedback loop between AMPK and mTORC1 is crucial for the proper dynamic features of the control network. Our computer simulations have further proved the dynamical characteristic of AMPK-mTORC1-ULK1 controlled cellular nutrient sensing.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Morte Celular Autofágica/fisiologia , Retroalimentação Fisiológica/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Transdução de Sinais/fisiologia , Estresse Fisiológico , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Ativação Enzimática/fisiologia , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína 1 do Complexo Esclerose Tuberosa/metabolismo , Proteína 2 do Complexo Esclerose Tuberosa/metabolismo
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