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1.
Front Immunol ; 15: 1384406, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38596681

RESUMO

Introduction: The autoimmune response in type 1 diabetes (T1D), in which the beta cells expressing aberrant or modified proteins are killed, resembles an effective antitumor response. Defective ribosomal protein products in tumors are targets of the anti-tumor immune response that is unleashed by immune checkpoint inhibitor (ICI) treatment in cancer patients. We recently described a defective ribosomal product of the insulin gene (INS-DRiP) that is expressed in stressed beta cells and targeted by diabetogenic T cells. T1D patient-derived INS-DRiP specific T cells can kill beta cells and are present in the insulitic lesion. T cells reactive to INS-DRiP epitopes are part of the normal T cell repertoire and are believed to be kept in check by immune regulation without causing autoimmunity. Method: T cell autoreactivity was tested using a combinatorial HLA multimer technology measuring a range of epitopes of islet autoantigens and neoantigen INS-DRiP. INS-DRiP expression in human pancreas and insulinoma sections was tested by immunohistochemistry. Results: Here we report the induction of islet autoimmunity to INS-DRiP and diabetes after ICI treatment and successful tumor remission. Following ICI treatment, T cells of the cancer patient were primed against INS-DRiP among other diabetogenic antigens, while there was no sign of autoimmunity to this neoantigen before ICI treatment. Next, we demonstrated the expression of INS-DRiP as neoantigen in both pancreatic islets and insulinoma by staining with a monoclonal antibody to INS-DRiP. Discussion: These results bridge cancer and T1D as two sides of the same coin and point to neoantigen expression in normal islets and insulinoma that may serve as target of both islet autoimmunity and tumor-related autoimmunity.


Assuntos
Diabetes Mellitus Tipo 1 , Insulinoma , Neoplasias Pancreáticas , Humanos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/terapia , Autoimunidade/genética , Insulinoma/genética , Insulinoma/terapia , Insulinoma/complicações , Autoantígenos , Insulina , Epitopos , Imunoterapia/métodos
2.
Endocr Relat Cancer ; 31(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38552306

RESUMO

Insulinoma and glucagonoma are two rare functioning neoplasms of the neuroendocrine cells of the pancreas, respectively, characterized by an uncontrolled over-secretion of insulin or glucagon, responsible for the development of the hypoglycemic syndrome and the glucagonoma syndrome. They prevalently arise as sporadic tumors; only about 10% of cases develop in the context of rare inherited tumor syndromes, such as multiple endocrine neoplasia type 1 (MEN1), neurofibromatosis type 1 (NF1), and tuberous sclerosis complex (TSC), being the result of an autosomal-dominant germline heterozygous loss-of-function mutation in a tumor-suppressor gene. Here, we reviewed the main epidemiological and clinical aspects of insulinoma and glucagonoma in the context of genetic syndromes.


Assuntos
Glucagonoma , Insulinoma , Neoplasia Endócrina Múltipla Tipo 1 , Neoplasias Pancreáticas , Humanos , Insulinoma/genética , Insulinoma/patologia , Glucagonoma/genética , Glucagonoma/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasia Endócrina Múltipla Tipo 1/genética , Pâncreas/patologia
3.
Genes (Basel) ; 14(10)2023 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-37895301

RESUMO

INTRODUCTION: Non-diabetic hypoglycemia (NDH) is a collective term including the multiple causes of hypoglycemic syndrome not due to diabetes mellitus. NDH may result from insulinoma, IGF-2-omas, hypocorticism, Hirata's disease, genital disorders of glucose metabolism, etc. One of the most common causes of NDH faced by an endocrinologist is insulinoma, which in turn can be part of the hereditary syndrome of multiple endocrine neoplasia type 1 (MEN1). Congenital disorders of glucose metabolism in adult patients, on the contrary, are diagnosed extremely rarely, since they usually manifest in childhood. This article presents a unique clinical case of a patient with NDH and genetically verified MEN1 in combination with congenital hyperinsulinism due to an ABCC8 gene mutation. CASE REPORT: A 43-year-old patient with hypoglycemic symptoms from childhood is presented, in whom multiple pancreatic tumors and fluctuations in glycemia from 38.7 mg/dL to 329.7 mg/dL (2.15 to 18.3 mmol/L) were detected in adulthood, but a mild course of hypoglycemic syndrome was noted. Numerous examinations that were performed to establish an accurate diagnosis are described, signs that served as a reason for expanding the complex of studies are indicated, possible pathogenetic mechanisms of the mild course of hypoglycemic syndrome and hyperglycemic conditions are discussed. CONCLUSION: This case report is original and highlights that we must always remain intolerant of the inexplicable. Conducting an extended gene study can help perform a correct diagnosis in complex cases.


Assuntos
Hiperinsulinismo Congênito , Insulinoma , Neoplasia Endócrina Múltipla Tipo 1 , Adulto , Humanos , Neoplasia Endócrina Múltipla Tipo 1/genética , Insulinoma/genética , Insulinoma/patologia , Mutação em Linhagem Germinativa , Hipoglicemiantes , Glucose , Receptores de Sulfonilureias/genética
4.
Sci Rep ; 13(1): 9260, 2023 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-37286698

RESUMO

ATP6AP2, also known as (pro)renin receptor, has been shown to be expressed in several tissues including pancreatic ß cells. Whereas ATP6AP2 plays an important role in regulating insulin secretion in mouse pancreatic ß cells, the expression profiles and roles of ATP6AP2 in human pancreatic endocrine cells and neuroendocrine tumor cells remain unclear. Here in this study, we investigated the expression profiles of ATP6AP2 in pancreatic endocrine cells, and found that ATP6AP2 is robustly expressed in pancreatic insulinoma cells as well as in normal ß cells. Although ATP6AP2 was also expressed in low-grade neuroendocrine tumors, it was not or faintly detected in intermediate- and high-grade neuroendocrine tumors. Knockdown experiments of the Atp6ap2 gene in rat insulinoma-derived INS-1 cells demonstrated decreased cell viability accompanied by a significant increase in apoptotic cells. Taken together, these findings suggest that ATP6AP2 plays a role in maintaining cellular homeostasis in insulinoma cells, which could lead to possible therapeutic approaches for endocrine tumors.


Assuntos
Células Secretoras de Insulina , Insulinoma , Tumores Neuroendócrinos , Neoplasias Pancreáticas , ATPases Vacuolares Próton-Translocadoras , Camundongos , Ratos , Animais , Humanos , Células Secretoras de Insulina/metabolismo , Insulinoma/genética , Insulinoma/metabolismo , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/metabolismo , Sobrevivência Celular/genética , ATPases Vacuolares Próton-Translocadoras/metabolismo , Receptores de Superfície Celular/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Receptor de Pró-Renina
5.
Front Endocrinol (Lausanne) ; 14: 1127173, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37152923

RESUMO

Background: Insulinomas are very rare in childhood with sparse knowledge on the clinical aspects and the presence of Multiple Endocrine Neoplasia type 1 (MEN1). Methods: We conducted a retrospective review of patients diagnosed with insulinoma between 1995 and 2021, presenting to one referral centre in Russia. Clinical, biochemical, genetic, imaging and histological data were collected. In addition, follow-up and family data were obtained. Results: A total of twenty-two children aged 5 to 16 years were identified. The median (range) gap between the first hypoglycaemia symptoms and diagnosis was 10 (1-46) months. Twelve children (55%) were misdiagnosed to have epilepsy and were treated with anticonvulsants before hypoglycemia was revealed. Contrast enhanced MRI and/or CT were accurate to localize the lesion in 82% (n=18). Five patients (23%) had multiple pancreatic lesions. All children underwent surgical treatment. The median (range) diameter of removed tumors was 1.5 (0.3-6) cm. Histopathological studies confirmed the presence of insulinoma in all cases. Immunohistochemical studies revealed G2 differentiation grade in 10 out of 17 cases. Two patients were diagnosed with metastatic insulinoma. One of them had metastases at the time of insulinoma diagnosis, while the other was diagnosed with liver metastases eight years after the surgery. Eight children (36%) were found to carry MEN1 mutations, inherited n=5, de novo n=1, no data, n=2. Children with MEN1 had significantly higher number of pancreatic tumors compared to sporadic cases. All of them developed additional MEN1 symptoms during the following 2-13 years. In the five patients with inherited MEN1, seven family members had hitherto undiscovered MEN1 manifestations. Conclusions: In this large cohort of children with rare pediatric insulinomas, MEN1 syndrome and G2 tumors were frequent, as well as hitherto undiscovered MEN1 manifestations in family members. Our data emphasize the need of genetic testing in all children with insulinoma and their relatives, even in the absence of any other features, as well as the importance of a prolonged follow-up observation.


Assuntos
Hipoglicemia , Insulinoma , Neoplasia Endócrina Múltipla Tipo 1 , Neoplasias Pancreáticas , Humanos , Criança , Insulinoma/diagnóstico , Insulinoma/genética , Insulinoma/patologia , Estudos Retrospectivos , Neoplasia Endócrina Múltipla Tipo 1/genética , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Encaminhamento e Consulta
6.
Endokrynol Pol ; 74(1): 31-46, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36847722

RESUMO

INTRODUCTION: Multiple endocrine neoplasia type 1 (MEN1) is a monogenic disease caused by inactivating variants in the MEN1 gene. Although the reason for its development is well-known, disease phenotypes are unpredictable and differ even among carriers of the same pathogenic driver mutation. Genetic, epigenetic, and environmental factors may play a role in driving the individual phenotype. Those factors, however, still mostly remain unidentified. In our work, we focused on the inherited genetic background in pancreatic neuroendocrine neoplasms (pNENs) in MEN1 patients, and the pancreatic tumour subgroup with insulinoma. MATERIAL AND METHODS: Whole exome sequencing was performed in MEN1 patients. The symptoms of interest were pancreatic neuroendocrine tumours in one analysis and insulinoma in the second. The study included families as well as unrelated cases. Genes with variants that are not neutral to the encoded gene product were defined in symptom-positive patients as compared to symptom-negative controls. The interpretation of the results was based on functional annotations and pathways shared between all patients with the given symptom in the course of MEN1. RESULTS: Whole-exome screening of family members and unrelated patients with and without pNENs revealed a number of pathways that are common for all the analysed cases with pNENs. Those included pathways crucial for morphogenesis and development, proper insulin signalling, and structural cellular organization. An additional analysis of insulinoma pNEN patients revealed additional pathways engaged in glucose and lipid homeostasis, and several non-canonical insulin-regulating mechanisms. CONCLUSIONS: Our results show the existence of pathways that are identified in a non-literature-predefined manner, which might have a modifying function in MEN1, differentiating the specific clinical outcomes. Those results, although preliminary, provide evidence of the reasonableness of performing large-scale studies addressing the genetic background of MEN1 patients in determining their individual outcomes.


Assuntos
Insulinoma , Neoplasia Endócrina Múltipla Tipo 1 , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Humanos , Insulinoma/genética , Neoplasia Endócrina Múltipla Tipo 1/genética , Sequenciamento do Exoma , Tumores Neuroendócrinos/genética , Neoplasias Pancreáticas/genética , Insulina , Patrimônio Genético
7.
Endocr Relat Cancer ; 30(5)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36779771

RESUMO

Insulinomas are rare functional pancreatic neuroendocrine tumors. While most insulinomas are indolent and cured after surgery, 10-15% of cases show aggressive or malignant tumor behavior and metastasize locally or to distant organs. Patients with metastatic insulinoma survive significantly shorter. Recognizing aggressive insulinomas can help to predict prognosis, guide therapy and determine follow-up intensity after surgery. This review offers a summary of the literature on the significant clinical, pathological, genetic and epigenetic differences between indolent and aggressive insulinomas. Aggressive insulinomas are characterized by rapid onset of symptoms, larger size, expression of ARX and alpha-1-antitrypsin and decreased or absent immunohistochemical expression of insulin, PDX1 and GLP-1R. Moreover, aggressive insulinomas often harbor ATRX or DAXX mutations, the alternative lengthening of telomeres phenotype and chromosomal instability. Tumor grade and MEN1 and YY1 mutations are less useful for predicting behavior. Aggressive insulinomas have similarities to normal alpha-cells and non-functional pancreatic neuroendocrine tumors, while indolent insulinomas remain closely related to normal beta-cells. In conclusion, indolent and aggressive insulinoma are different entities, and distinguishing these will have future clinical value in determining prognosis and treatment.


Assuntos
Insulinoma , Neoplasias Pancreáticas , Humanos , Insulinoma/genética , Insulinoma/patologia , Neoplasias Pancreáticas/patologia , Prognóstico
8.
Int J Mol Sci ; 24(4)2023 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-36835048

RESUMO

Pancreatic neuroendocrine neoplasms (pNEN) are rare and heterogeneous tumors. Previous investigations have shown that autophagy can be a target for cancer therapy. This study aimed to determine the association between the expression of autophagy-associated gene transcripts and clinical parameters in pNEN. In total, 54 pNEN specimens were obtained from our human biobank. The patient characteristics were retrieved from the medical record. RT-qPCR was performed to assess the expression of the autophagic transcripts BECN1, MAP1LC3B, SQSTM1, UVRAG, TFEB, PRKAA1, and PRKAA2 in the pNEN specimens. A Mann-Whitney U test was used to detect differences in the expression of autophagic gene transcripts between different tumor characteristics. This study showed that G1 sporadic pNEN have a higher expression of autophagic genes compared to G2. Lymphatic and distant metastasis occurred significantly more often in pNEN with a decreased expression of the autophagic genes. Within sporadic pNEN, the insulinomas express higher levels of autophagic transcripts than gastrinomas and non-functional pNEN. MEN1-associated pNEN show a higher expression of autophagic genes than sporadic pNEN. In summary, a decreased expression of autophagic transcripts distinguishes metastatic from non-metastatic sporadic pNEN. The significance of autophagy as a molecular marker for prognosis and therapy decisions needs to be further investigated.


Assuntos
Autofagia , Tumores Neuroendócrinos , Neoplasias Pancreáticas , Humanos , Gastrinoma/genética , Insulinoma/genética , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Autofagia/genética
9.
J Clin Invest ; 132(15)2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35700053

RESUMO

Resistance to regeneration of insulin-producing pancreatic ß cells is a fundamental challenge for type 1 and type 2 diabetes. Recently, small molecule inhibitors of the kinase DYRK1A have proven effective in inducing adult human ß cells to proliferate, but their detailed mechanism of action is incompletely understood. We interrogated our human insulinoma and ß cell transcriptomic databases seeking to understand why ß cells in insulinomas proliferate, while normal ß cells do not. This search reveals the DREAM complex as a central regulator of quiescence in human ß cells. The DREAM complex consists of a module of transcriptionally repressive proteins that assemble in response to DYRK1A kinase activity, thereby inducing and maintaining cellular quiescence. In the absence of DYRK1A, DREAM subunits reassemble into the pro-proliferative MMB complex. Here, we demonstrate that small molecule DYRK1A inhibitors induce human ß cells to replicate by converting the repressive DREAM complex to its pro-proliferative MMB conformation.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Insulinoma , Neoplasias Pancreáticas , Adulto , Proliferação de Células , Humanos , Células Secretoras de Insulina/metabolismo , Insulinoma/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/metabolismo
10.
Sci Rep ; 12(1): 7713, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35562179

RESUMO

The role of ER Ca2+ release via ryanodine receptors (RyR) in pancreatic ß-cell function is not well defined. Deletion of RyR2 from the rat insulinoma INS-1 (RyR2KO) enhanced IP3 receptor activity stimulated by 7.5 mM glucose, coincident with reduced levels of the protein IP3 Receptor Binding protein released with Inositol 1,4,5 Trisphosphate (IRBIT). Insulin content, basal (2.5 mM glucose) and 7.5 mM glucose-stimulated insulin secretion were reduced in RyR2KO and IRBITKO cells compared to controls. INS2 mRNA levels were reduced in both RyR2KO and IRBITKO cells, but INS1 mRNA levels were specifically decreased in RyR2KO cells. Nuclear localization of S-adenosylhomocysteinase (AHCY) was increased in RyR2KO and IRBITKO cells. DNA methylation of the INS1 and INS2 gene promotor regions was very low, and not different among RyR2KO, IRBITKO, and controls, but exon 2 of the INS1 and INS2 genes was more extensively methylated in RyR2KO and IRBITKO cells. Exploratory proteomic analysis revealed that deletion of RyR2 or IRBIT resulted in differential regulation of 314 and 137 proteins, respectively, with 41 in common. These results suggest that RyR2 regulates IRBIT levels and activity in INS-1 cells, and together maintain insulin content and secretion, and regulate the proteome, perhaps via DNA methylation.


Assuntos
Insulinoma , Neoplasias Pancreáticas , Animais , Linhagem Celular , Glucose , Insulina/metabolismo , Insulinoma/genética , Neoplasias Pancreáticas/genética , Proteômica , RNA Mensageiro , Ratos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo
11.
Zhonghua Yi Xue Za Zhi ; 102(14): 1028-1033, 2022 Apr 12.
Artigo em Chinês | MEDLINE | ID: mdl-35399023

RESUMO

Objective: To study the alterations of p16 gene and its expression in insulinoma and to correlate the findings with clinicopathological characteristics. Methods: Expression of p16 protein was detected in 72 insulinomas and 49 para-tumoral or normal pancreatic tissues by immunohistochemical staining. Genomic DNA was isolated from 32 tumor tissue and 17 paired pancreatic tissues and bisulfite-modified. Promoter methylation status of p16 gene was detected in 32 tumor tissue and 17 paired pancreatic tissues by methylation specific PCR. The findings were correlated with the clinicopathological features. Results: There were 30 males and 42 females in all 72 patients, aged (46.5±14.0) years. Loss or reduced expression of p16 protein was found in 42 of 72 insulinomas (58.3%) while loss or reduced expression of p16 was seen in only 34.7% (17/49) of para-tumoral or normal pancreatic tissues (χ²=6.52, P=0.011). Promoter methylation of p16 gene was found in 13 of 32 insulinomas (40.6%) and only 2 of 17 (11.8%) para-tumoral tissues (χ²=4.35, P=0.037). The expression of p16 protein in insulinoma was not associated with clinicopathological features such as gender, age, tumor size and tumor grade. Conclusions: Loss or reduced expression of p16 protein was found in insulinomas, and associated with p16 gene promoter methylation.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina , Metilação de DNA , Insulinoma , Neoplasias Pancreáticas , Adulto , Inibidor p16 de Quinase Dependente de Ciclina/genética , Feminino , Genes p16 , Humanos , Insulinoma/genética , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/genética
12.
Gene ; 822: 146317, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35182680

RESUMO

Kinesin family member 4A (KIF4A), located in the human chromosome band Xq13.1, is aberrantly overexpressed in various cancers. Our study intended to assess the expression of KIF4A in insulinoma and to gain new insights into the molecular mechanisms of this rare disease. First, KIF4A was significantly recruited in pancreatic endocrine cells relative to other cell types. A significant correlation existed between the overexpression of KIF4A and the poor survival of pancreatic adenocarcinoma patients. As revealed by CCK-8, TUNEL assay, flow cytometry, wound healing, Matrigel-transwell, senescence-associated ß-galactosidase staining, ELISA, and subcutaneous tumor formation analysis in nude mice, knocking down KIF4A significantly inhibited the growth and metastasis of insulinoma cells in vivo and in vitro. Mechanistically, we observed that KIF4A promoter sequences had reduced H3K27me3 modifications, and decline in enhancer of zeste homolog-2 (EZH2) expression promoted KIF4A expression by reducing the modification, thus leading to insulinoma. Moreover, EZH2 knockdown-induced insulinoma cell proliferation was dependent on KIF4A overexpression since KIF4A knockdown eradicated shEZH2-induced proliferation of insulinoma cells. In summary, KIF4A was identified as a possible therapeutic target for insulinoma.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Histonas/metabolismo , Insulinoma/patologia , Cinesinas/genética , Neoplasias Pancreáticas/patologia , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Código das Histonas , Humanos , Insulinoma/genética , Insulinoma/metabolismo , Camundongos , Transplante de Neoplasias , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Regiões Promotoras Genéticas , Regulação para Cima
13.
Front Endocrinol (Lausanne) ; 12: 760154, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34737724

RESUMO

Insulinomatosis is characterized by monohormonality of multiple macro-tumors and micro-tumors that arise synchronously and metachronously in all regions of the pancreas, and often recurring hypoglycemia. One of the main characteristics of insulinomatosis is the presence of insulin-expressing monohormonal endocrine cell clusters that are exclusively composed of proliferating insulin-positive cells, are less than 1 mm in size, and show solid islet-like structure. It is presumed that insulinomatosis affects the entire population of ß-cells. With regards to molecular genetics, this phenomenon is not related to mutation in MEN1 gene and is more similar to sporadic benign insulinomas, however, at the moment molecular genetics of this disease remains poorly investigated. NGS sequencing was performed with a panel of 409 cancer-related genes. Results of sequencing were analyzed by bioinformatic algorithms for detecting point mutations and copy number variations. DNA copy number variations were detected that harbor a large number of genes in insulinoma and fewer genes in micro-tumors. qPCR was used to confirm copy number variations at ATRX, FOXL2, IRS2 and CEBPA genes. Copy number alterations involving FOXL2, IRS2, CEBPA and ATRX genes were observed in insulinoma as well as in micro-tumors samples, suggesting that alterations of these genes may promote malignization in the ß-cells population.


Assuntos
Variações do Número de Cópias de DNA , Insulinoma/genética , Neoplasias Pancreáticas/genética , Idoso , Humanos , Insulinoma/patologia , Masculino , Pessoa de Meia-Idade , Pâncreas/patologia , Neoplasias Pancreáticas/patologia
14.
FEBS Lett ; 595(24): 3042-3055, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34780071

RESUMO

Selenium is an essential trace element of interest for its potential role in glucose homeostasis. The present study investigated the impact of selenium supplementation as selenomethionine (SeMet) on insulin secretion in MIN6-K8 cells, a pancreatic ß-cell model. We found that SeMet enhanced percent glucose-induced insulin secretion, while also increasing tolbutamide- and KCl-induced percent insulin secretion. RNA-sequencing showed that SeMet supplementation altered expression of several selenoproteins, including glutathione peroxidase 3 (Gpx3) and selenoprotein P (SelP). Targeted knockdown of Gpx3 increased both percent and total insulin release, while SelP knockdown increased insulin content and insulin release. Collectively, these studies support a putative role for selenium and selenoproteins in the regulation of insulin secretion, glucose homeostasis, and diabetes risk.


Assuntos
Secreção de Insulina/efeitos dos fármacos , Insulinoma/metabolismo , Selenometionina/farmacologia , Animais , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glutationa Peroxidase/metabolismo , Insulina/metabolismo , Insulinoma/genética , Insulinoma/patologia , Camundongos , Potássio/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Selenoproteínas/genética , Selenoproteínas/metabolismo , Tolbutamida/farmacologia
16.
Nutrients ; 13(9)2021 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-34578896

RESUMO

Impaired insulin secretion is one of the main causes of type 2 diabetes. Cholesterol accumulation-induced lipotoxicity contributes to impaired insulin secretion in pancreatic beta cells. However, the detailed mechanism in this process remains unclear. In this study, we proved that oxidized low-density lipoprotein (OxLDL) reduced insulin content, decreased PDX-1 expression, and impaired glucose-stimulated insulin secretion (GSIS) in INS-1 cells, which were rescued by addition of high-density lipoprotein (HDL). OxLDL receptors and cholesterol content were increased by OxLDL. Consistently, OxLDL suppressed cholesterol transporter ABCA1 expression and transcription in a dose-dependent and time-dependent manner. Inhibition of MEK by its specific inhibitor, PD98059, altered the effect of OxLDL on ABCA1 transcription and activation of ERK. Next, chromatin immunoprecipitation assay demonstrated that liver X receptor (LXR) could directly bind to ABCA1 promoter and this binding was inhibited by OxLDL. Furthermore, OxLDL decreased the nuclear LXR expression, which was prevented by HDL. LXR-enhanced ABCA1 transcription was suppressed by OxLDL, and the effect was cancelled by mutation of the LXR-binding sites. In summary, our study shows that OxLDL down-regulates ABCA1 expression by MEK/ERK/LXR pathway, leading to cholesterol accumulation in INS-1 cells, which may result in impaired insulin synthesis and GSIS.


Assuntos
Transportador 1 de Cassete de Ligação de ATP/genética , Regulação para Baixo/genética , Insulinoma/genética , Lipoproteínas LDL/genética , Receptores X do Fígado/genética , Sistema de Sinalização das MAP Quinases/genética , Transportador 1 de Cassete de Ligação de ATP/metabolismo , Animais , Células Cultivadas , Regulação para Baixo/fisiologia , Expressão Gênica/genética , Humanos , Insulinoma/metabolismo , Lipoproteínas LDL/metabolismo , Receptores X do Fígado/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Ratos
17.
Ann Endocrinol (Paris) ; 82(2): 112-120, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33839123

RESUMO

In 1953, for the first time, Paul Wermer described a family presenting endocrine gland neoplasms over several generations. The transmission was autosomal dominant and the penetrance was high. Forty years later in 1997, the multiple endocrine neoplasia type 1 (MEN1) gene was sequenced, thus enabling diagnosis and early optimal treatment. Patients carrying the MEN1 gene present endocrine but also non-endocrine tumors. Parathyroid, pancreatic and pituitary impairment are the three main types of endocrine involvement. The present article details therapeutic management of hyperparathyroidism, neuroendocrine pancreatic tumors and pituitary adenomas in patients carrying the MEN1 gene. Significant therapeutic progress has in fact been made in the last few years. As concerns the parathyroid glands, screening of family members and regular monitoring of affected subjects now raise the question of early management of parathyroid lesions and optimal timing of parathyroid surgery. As concerns the duodenum-pancreas, proton-pump inhibitors are able to control gastrin-secreting syndrome, reducing mortality in MEN1 patients. Mortality in MEN1 patients is no longer mainly secondary to uncontrolled hormonal secretion but to metastatic (mainly pancreatic) disease progression. Tumor risk requires regular monitoring of morphological assessment, leading to iterative pancreatic surgery in a large number of patients. Finally, pituitary adenomas in MEN1 patients are traditionally described as aggressive, invasive and resistant to medical treatment. However, regular pituitary screening showed them to be in fact infra-centimetric and non-secreting in the majority of patients. Consequently, it is necessary to regularly monitor MEN1 patients, with regular clinical, biological and morphological work-up. Several studies showed that this regular monitoring impairs quality of life. Building a relationship of trust between patients and care provider is therefore essential. It enables the patient to be referred for psychological or psychiatric care in difficult times, providing long-term support and preventing any breakdown in continuity of care.


Assuntos
Neoplasia Endócrina Múltipla Tipo 1/genética , Neoplasia Endócrina Múltipla Tipo 1/terapia , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Feminino , Gastrinoma/genética , Gastrinoma/terapia , Predisposição Genética para Doença , Humanos , Hiperparatireoidismo/genética , Hiperparatireoidismo/terapia , Insulinoma/genética , Insulinoma/terapia , Masculino , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/terapia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/terapia , Paratireoidectomia , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/terapia , Neoplasias do Timo/genética , Neoplasias do Timo/terapia
18.
Pancreas ; 50(10): 1450-1453, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35041347

RESUMO

ABSTRACT: Sporadic adult insulinomatosis is an extremely rare clinical condition. Adult proinsulinomatosis has not yet been described. We report the case of a 48-year-old female patient with recurrent hypoglycemia caused by benign proinsulin-secreting pancreatic neuroendocrine neoplasias (pNENs) with no history of multiple endocrine neoplasia type 1. Initial workup revealed elevated serum proinsulin levels and a positive fasting test. Magnetic resonance imaging and endosonography visualized 2 pNENs in the pancreatic body and tail that were treated by robotic-assisted enucleation. After initial biochemical cure, the patient's hypoglycemia recurred 3 months after surgery. Imaging showed a new lesion in the pancreatic body, so that now a spleen-preserving subtotal distal pancreatectomy was performed. The pathological examination revealed 17 neuroendocrine microadenomas and 1 well-differentiated pNEN (Ki-67% 1%-2%) of 22-mm size as well as more than 200 (pro)insulin-producing ß-cell precursor lesions, confirming the diagnosis of adult proinsulinomatosis. Mutation analysis of the germline DNA identified the in-frame deletion mutation (p.His207del) in the MAFA gene on chromosome 8. The patient was biochemically cured 16 months after the last surgical resection. Similarly to adult insulinomatosis, the presence of proinsulin-secreting tumors causes recurrent hypoglycemia and might be associated with germline mutations in the MAFA gene.


Assuntos
Hipoglicemia/etiologia , Insulinoma/complicações , Fatores de Transcrição Maf Maior/genética , Glicemia/análise , Glicemia/biossíntese , Feminino , Alemanha , Humanos , Hipoglicemia/genética , Insulinoma/genética , Fatores de Transcrição Maf Maior/metabolismo , Pessoa de Meia-Idade , Mutação/genética , Proinsulina/sangue
19.
Can J Physiol Pharmacol ; 99(3): 303-312, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32758099

RESUMO

Diabetes mellitus (DM) is a type of metabolic disorder characterized by long-term hyperglycemia. Accumulating evidence shows that long noncoding RNAs (lncRNAs) play significant roles in the occurrence and development of DM. This study intended to investigate the role of lncRNA plasmacytoma variant translocation 1 (PVT1) in rat insulinoma (INS-1) cells damaged by streptozotocin (STZ) and to identify the potential mechanisms. Firstly, PVT1 expression in INS-1 cells was assessed using RT-qPCR after STZ stimulation. After PVT1-knockdown, cell apoptosis, the contents of oxidative stress related markers, and changes in insulin secretion were detected. Results indicated that PVT1 was remarkably upregulated after STZ stimulation. PVT1-knockdown inhibited STZ-induced oxidative stress and apoptosis of INS-1 cells. Moreover, the insulin secretory capacity was notably elevated following PVT1 silencing. Subsequently, a luciferase reporter assay verified that miR-181a-5p was directly targeted by PVT1. The rescue assays revealed that miR-181a-5p inhibitor dramatically abrogated the effects of PVT1 silencing on oxidative stress, apoptosis, and insulin secretion. Taken together, these findings demonstrated that PVT1-knockdown could ameliorate STZ-induced oxidative stress and apoptosis and elevate insulin secretory capacity in pancreatic ß cells by regulating miR-181a-5p, suggesting a promising biomarker in DM diagnosis and treatment.


Assuntos
Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/terapia , Terapia Genética , Secreção de Insulina/genética , Células Secretoras de Insulina/patologia , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Inativação Gênica , Insulinoma/genética , MicroRNAs/antagonistas & inibidores , Estresse Oxidativo/efeitos dos fármacos , Neoplasias Pancreáticas/genética , Ratos
20.
Front Endocrinol (Lausanne) ; 11: 563267, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33101198

RESUMO

Epidemiologic analyses have shed light on an association between type 2 diabetes (T2D) and pancreatic ductal adenocarcinoma (PDAC). Recent data also suggest a potential relationship between T2D and insulinoma. Under rare circumstances, type 1 diabetes (T1D) can also be implicated in tumorigenesis. The biological mechanisms underlying such relationships are extremely complex. Some genetic factors contributing to the development of T2D are shared with pancreatic exocrine and endocrine tumors. Obesity and overweight can also contribute to the initiation and severity of T2D, while aging may influence both endocrine and exocrine tumors. Finally, pharmacological treatments of T2D may have an impact on PDAC. On the other hand, some treatments for insulinoma can trigger diabetes. In the present minireview, we discuss the cellular and molecular mechanisms that could explain these interactions. This analysis may help to define new potential therapeutic strategies.


Assuntos
Envelhecimento/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Insulinoma/metabolismo , Obesidade/metabolismo , Neoplasias Pancreáticas/metabolismo , Envelhecimento/genética , Envelhecimento/patologia , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Humanos , Insulinoma/genética , Insulinoma/patologia , Obesidade/genética , Obesidade/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fatores de Risco
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