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1.
Int J Mol Sci ; 25(5)2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38473908

RESUMO

As the burden of type 2 diabetes (T2D) continues to escalate globally, there is a growing need for novel, less-invasive biomarkers capable of early diabetes detection and monitoring of disease progression. Liquid biopsy, recognized for its minimally invasive nature, is increasingly being applied beyond oncology, and nevertheless shows its potential when the collection of the tissue biopsy is not possible. This diagnostic approach involves utilizing liquid biopsy markers such as cell-free nucleic acids, extracellular vesicles, and diverse metabolites for the molecular diagnosis of T2D and its related complications. In this context, we thoroughly examine recent developments in T2D liquid biopsy research. Additionally, we discuss the primary challenges and future prospects of employing liquid biopsy in the management of T2D. Prognosis, diagnosis and monitoring of T2D through liquid biopsy could be a game-changing technique for personalized diabetes management.


Assuntos
Ácidos Nucleicos Livres , Diabetes Mellitus Tipo 2 , Vesículas Extracelulares , Células Neoplásicas Circulantes , Humanos , Diabetes Mellitus Tipo 2/metabolismo , Biomarcadores Tumorais/metabolismo , Biópsia Líquida/métodos , Vesículas Extracelulares/metabolismo , Ácidos Nucleicos Livres/metabolismo , Células Neoplásicas Circulantes/patologia
2.
Int J Mol Sci ; 25(4)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38396657

RESUMO

The primary treatment for autoimmune Diabetes Mellitus (Type 1 Diabetes Mellitus-T1DM) is insulin therapy. Unfortunately, a multitude of clinical cases has demonstrated that the use of insulin as a sole therapeutic intervention fails to address all issues comprehensively. Therefore, non-insulin adjunct treatment has been investigated and shown successful results in clinical trials. Various hypoglycemia-inducing drugs such as Metformin, glucagon-like peptide 1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors, amylin analogs, and Sodium-Glucose Cotransporters 2 (SGLT-2) inhibitors, developed good outcomes in patients with T1DM. Currently, SGLT-2 inhibitors have remarkably improved the treatment of patients with diabetes by preventing cardiovascular events, heart failure hospitalization, and progression of renal disease. However, their pharmacological potential has not been explored enough. Thus, the substantial interest in SGLT-2 inhibitors (SGLT-2is) underlines the present review. It begins with an overview of carrier-mediated cellular glucose uptake, evidencing the insulin-independent transport system contribution to glucose homeostasis and the essential roles of Sodium-Glucose Cotransporters 1 and 2. Then, the pharmacological properties of SGLT-2is are detailed, leading to potential applications in treating T1DM patients with automated insulin delivery (AID) systems. Results from several studies demonstrated improvements in glycemic control, an increase in Time in Range (TIR), a decrease in glycemic variability, reduced daily insulin requirements without increasing hyperglycemic events, and benefits in weight management. However, these advantages are counterbalanced by increased risks, particularly concerning Diabetic Ketoacidosis (DKA). Several clinical trials reported a higher incidence of DKA when patients with T1DM received SGLT-2 inhibitors such as Sotagliflozin and Empagliflozin. On the other hand, patients with T1DM and a body mass index (BMI) of ≥27 kg/m2 treated with Dapagliflozin showed similar reduction in hyperglycemia and body weight and insignificantly increased DKA incidence compared to the overall trial population. Additional multicenter and randomized studies are required to establish safer and more effective long-term strategies based on patient selection, education, and continuous ketone body monitoring for optimal integration of SGLT-2 inhibitors into T1DM therapeutic protocol.


Assuntos
Diabetes Mellitus Tipo 1 , Insulina , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Glucose/uso terapêutico , Hipoglicemiantes/efeitos adversos , Insulina/uso terapêutico , Estudos Multicêntricos como Assunto , Medição de Risco , Sódio , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose/uso terapêutico
3.
Life (Basel) ; 12(11)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36362945

RESUMO

The treatment of acute life-threatening events in patients suffering from chronic pathologies is problematic, as physicians need to consider multisystemic drug effects. Regarding Cerebrolysin, a Sonic Hedgehog signaling pathway amplifier and one of the few approved neurotrophic treatments for stroke patients, concerns of excessive Hedgehog pathway activation that could accelerate NAFLD progression to cirrhosis seem valid. We investigated stroke patients treated with Cerebrolysin that presented elevated levels of aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT). We also investigated the efficiency of Cerebrolysin in reversing the neurogenesis inhibition within the hippocampus in a mouse model of NAFLD by evaluating behavior and histological outcomes. NeuN, BrdU and Iba1 positive signals in the cortex and hippocampus of the animals were also observed. Clinically, Cerebrolysin improved AST levels in a majority of stroke patients with hepatic damage. The same treatment in an experimental setup was able to reverse anxiety-like behavior in MCD mice, reducing their freezing time from 333.61 ± 21.81 s in MCD animals to 229.17 ± 26.28 in treated ones. The use of Cerebrolysin did not improve short-term memory nor rescued cell multiplication in the hippocampus after MCD food intake. Understanding the neuroprotective and neurotrophic effects that drugs have on NAFLD patients can significantly contribute to a suitable therapeutic approach.

4.
Int J Mol Sci ; 23(14)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35886861

RESUMO

Metabolic syndrome (MetSyn) is a major health problem affecting approximately 25% of the worldwide population. Since the gut microbiota is highly connected to the host metabolism, several recent studies have emerged to characterize the role of the microbiome in MetSyn development and progression. To this end, our study aimed to identify the microbiome patterns which distinguish MetSyn from type 2 diabetes mellitus (T2DM). We performed 16S rRNA amplicon sequencing on a cohort of 70 individuals among which 40 were MetSyn patients. The microbiome of MetSyn patients was characterised by reduced diversity, loss of butyrate producers (Subdoligranulum, Butyricicoccus, Faecalibacterium prausnitzii) and enrichment in the relative abundance of fungal populations. We also show a link between the gut microbiome and lipid metabolism in MetSyn. Specifically, low-density lipoproteins (LDL) and high-density lipoproteins (HDL) display a positive effect on gut microbial diversity. When interrogating the signature of gut microbiota in a subgroup of patients harbouring both MetSyn and T2DM conditions, we observed a significant increase in taxa such as Bacteroides, Clostridiales, and Erysipelotrichaceae. This preliminary study shows for the first time that T2DM brings unique signatures of gut microbiota in MetSyn patients. We also highlight the impact of metformin treatment on the gut microbiota. Metformin administration was linked to changes in Prevotellaceae, Rickenellaceae, and Clostridiales. Further research focusing on the microbiome-metabolome patterns is needed to clarify the exact association of various gut microbial communities with the progression of T2DM and the occurrence of various complications in MetSyn patients.


Assuntos
Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Síndrome Metabólica , Metformina , Butiratos/farmacologia , Clostridiales/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Metformina/farmacologia , Metformina/uso terapêutico , RNA Ribossômico 16S/genética
5.
Metabolites ; 12(3)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35323661

RESUMO

Metabolic syndrome (MetSyn) has a rapidly growing worldwide prevalence, affecting over 1 billion people. MetSyn is clustering many pathological conditions, which, untreated, could increase the risk and often lead to more severe metabolic defects such as type 2 diabetes and non-alcoholic fatty liver disease. Many data demonstrate the complex role of gut microbiota in the host metabolism, and hence, deciphering the microbiome patterns linked to MetSyn could enable us for novel diagnosis and monitoring markers and for better disease management. Moreover, interventions designed to alter patient microbiome composition may help prevent or decrease morbidity linked with MetSyn. However, the microbiome composition is largely different across geographically distinct populations. Our study investigated the microbiota and mycobiome patterns in Romanian metabolic syndrome patients. We also correlated the identified microbiome-mycobiome patterns with levels of metabolites important for host health such as short chain fatty acids, organic acids, and taurine. We found that MetSyn patients are harboring a microbiome enriched in Enterobacteriaceae, Turicibacter sp., Clostridium coccoides, and Clostridium leptum, while beneficial taxa such as Butyricicoccus sp., Akkermansia muciniphila, and Faecalibacterium prausnitzii were decreased. These microbiome changes were correlated with lower butyrate levels and increased succinate. In terms of mycobiome signatures, MetSyn was associated with a high abundance of Saccharomyces and Aspergillus species. Our data are the first reported on a Romanian population and confirming that the pathogenesis of MetSyn is closely related to gut microbiome and homeostasis.

6.
Brain Sci ; 11(10)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34679351

RESUMO

Patients with severe COVID-19 experience high-stress levels and thus are at risk for developing acute stress disorder (ASD) and/or post-traumatic stress disorder (PTSD). The present study aims to search for correlations between psychiatric response to stress and coping strategies among individuals with acute vs. remitted COVID-19. Ninety subjects with COVID-19 were included in the study, divided into two samples by disease category. Our focus was analysing the perceived stress intensity according to NSESSS and PCL-C-17 scales, and coping strategies with COPE-60. High NSESSS scores were found in 40% of acute patients, and 15.6% of remitted patients had high PCL-C-17 scores fulfilling the criteria for PTSD. We found a negative correlation between stress level and disease category. Acute patients used significantly more engagement and emotion-focused coping methods, but less disengagement types of coping than patients in the remitted phase. Remitted patients under high stress levels are prone to use disengagement and emotion-focused coping strategies. In conclusion, remitted COVID-19 patients experience lower levels of stress and use less emotion-focused strategies, except among those who developed PTSD post-COVID-19 infection, presenting with high-stress levels and using more disengagement and emotion-focused types of coping strategies.

7.
Hum Mutat ; 38(1): 78-85, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27650164

RESUMO

The aryl hydrocarbon receptor interacting protein (AIP) founder mutation R304* (or p.R304* ; NM_003977.3:c.910C>T, p.Arg304Ter) identified in Northern Ireland (NI) predisposes to acromegaly/gigantism; its population health impact remains unexplored. We measured R304* carrier frequency in 936 Mid Ulster, 1,000 Greater Belfast (both in NI) and 2,094 Republic of Ireland (ROI) volunteers and in 116 NI or ROI acromegaly/gigantism patients. Carrier frequencies were 0.0064 in Mid Ulster (95%CI = 0.0027-0.013; P = 0.0005 vs. ROI), 0.001 in Greater Belfast (0.00011-0.0047) and zero in ROI (0-0.0014). R304* prevalence was elevated in acromegaly/gigantism patients in NI (11/87, 12.6%, P < 0.05), but not in ROI (2/29, 6.8%) versus non-Irish patients (0-2.41%). Haploblock conservation supported a common ancestor for all the 18 identified Irish pedigrees (81 carriers, 30 affected). Time to most recent common ancestor (tMRCA) was 2550 (1,275-5,000) years. tMRCA-based simulations predicted 432 (90-5,175) current carriers, including 86 affected (18-1,035) for 20% penetrance. In conclusion, R304* is frequent in Mid Ulster, resulting in numerous acromegaly/gigantism cases. tMRCA is consistent with historical/folklore accounts of Irish giants. Forward simulations predict many undetected carriers; geographically targeted population screening improves asymptomatic carrier identification, complementing clinical testing of patients/relatives. We generated disease awareness locally, necessary for early diagnosis and improved outcomes of AIP-related disease.


Assuntos
Acromegalia/epidemiologia , Acromegalia/genética , Predisposição Genética para Doença , Gigantismo/epidemiologia , Gigantismo/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Acromegalia/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Substituição de Aminoácidos , Mapeamento Cromossômico , Estudos Transversais , Feminino , Frequência do Gene , Genótipo , Gigantismo/diagnóstico , Heterozigoto , Humanos , Irlanda/epidemiologia , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Fenótipo , Risco , Adulto Jovem
8.
Mol Cell Endocrinol ; 326(1-2): 25-9, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20347931

RESUMO

Pituitary tumours are benign neoplasms that may cause major endocrine dysfunction. Transgenic disruption of the cell cycle machinery frequently leads to pituitary adenoma formation in animal models. The molecular analysis of human pituitary tumours has found various alterations in the expression of cell cycle regulators: cyclins, cyclin-dependent kinases and their inhibitors. There are also different mechanisms (e.g. hypermethylation, frameshift mutations, increased proteasome degradation) responsible for changed expression in cyclin mRNA and protein. It is probable that the primary initiating events lie beyond the cell cycle and may be related to co-activation of Akt, MAP-kinase and beta-catenin pathways. Nevertheless, molecular CDK inhibitors may play a role in pituitary tumour treatment in the future.


Assuntos
Ciclinas/fisiologia , Neoplasias Hipofisárias/etiologia , Proteínas de Ciclo Celular/metabolismo , Ciclina E/metabolismo , Ciclina E/fisiologia , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/genética , Ciclinas/metabolismo , Humanos , Neoplasia Endócrina Múltipla Tipo 1/genética , Neoplasias , Hipófise/metabolismo , Hipófise/patologia , Neoplasias Hipofisárias/patologia
9.
Rev Med Chir Soc Med Nat Iasi ; 113(4): 996-1000, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20191865

RESUMO

Premenstrual dysphoric disorder (PMDD) consists in severe cognitive and mood changes, more aggressive as seen in premenstrual syndrome (PMS). These two syndromes are situated at the border between gynecology and psychiatry but the link between the two domains remains the neuroendocrine underlying mechanisms. In present, there are some molecular systems certainly proved as being involved, like estrogens. The hormonal pattern consists not in different levels of the hormones but different response to normal hormonal levels. The cyclical biochemical triggers are related to neurotransmitters as serotonin, endorphin and gamma-amino butyric acid (GABA). The heritability of the syndrome is sustained by genetic polymorphism in ESR1 gene. Thus, the PMDD is the result of multiple disturbances regarding neuroendocrine systems.


Assuntos
Sistema Hipotálamo-Hipofisário/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Síndrome Pré-Menstrual/fisiopatologia , Síndrome Pré-Menstrual/psicologia , Agressão/psicologia , Biomarcadores/metabolismo , Cognição , Endorfinas/biossíntese , Receptor alfa de Estrogênio/genética , Feminino , Humanos , Transtornos do Humor/etiologia , Ovário/fisiopatologia , Polimorfismo Genético , Síndrome Pré-Menstrual/genética , Síndrome Pré-Menstrual/metabolismo , Escalas de Graduação Psiquiátrica , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Fatores de Risco , Serotonina/biossíntese , Serotoninérgicos/metabolismo , Ácido gama-Aminobutírico/biossíntese
10.
Endocr Relat Cancer ; 15(4): 1099-114, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18701577

RESUMO

The molecular analysis of pituitary tumours has received a great deal of attention, although the majority of studies have concentrated on the genome and the transcriptome. We aimed to study the proteome of human pituitary adenomas. A protein array using 1005 monoclonal antibodies was used to study GH-, corticotrophin- and prolactin-secreting as well as non-functioning pituitary adenomas (NFPAs). Individual protein expression levels in the tumours were compared with the expression profile of normal pituitary tissue. Out of 316 proteins that were detected in the pituitary tissue samples, 116 proteins had not previously been described in human pituitary tissue. Four prominent differentially expressed proteins with potential importance to tumorigenesis were chosen for validation by immunohistochemistry and western blotting. In the protein array analysis heat shock protein 110 (HSP110), a chaperone associated with protein folding, and B2 bradykinin receptor, a potential regulator of prolactin secretion, were significantly overexpressed in all adenoma subtypes, while C-terminal Src kinase (CSK), an inhibitor of proto-oncogenic enzymes, and annexin II, a calcium-dependent binding protein, were significantly underexpressed in all adenoma subtypes. The immunohistochemical analysis confirmed the overexpression of HSP110 and B2 bradykinin receptor and underexpression of CSK and annexin II in pituitary adenoma cells when compared with their corresponding normal pituitary cells. Western blotting only partially confirmed the proteomics data: HSP110 was significantly overexpressed in prolactinomas and NFPAs, the B2 bradykinin receptor was significantly overexpressed in prolactinomas, annexin II was significantly underexpressed in somatotrophinomas, while CSK did not show significant underexpression in any tumour. Protein expression analysis of pituitary samples disclosed both novel proteins and putative protein candidates for pituitary tumorigenesis, though validation using conventional techniques are necessary to confirm the protein array data.


Assuntos
Adenoma/metabolismo , Biomarcadores Tumorais/metabolismo , Proteínas de Neoplasias/metabolismo , Hipófise/metabolismo , Neoplasias Hipofisárias/metabolismo , Adenoma/patologia , Western Blotting , Humanos , Hipófise/patologia , Neoplasias Hipofisárias/patologia , Análise Serial de Proteínas
11.
J Clin Endocrinol Metab ; 93(6): 2390-401, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18381572

RESUMO

CONTEXT: Mutations have been identified in the aryl hydrocarbon receptor-interacting protein (AIP) gene in familial isolated pituitary adenomas (FIPA). It is not clear, however, how this molecular chaperone is involved in tumorigenesis. OBJECTIVE: AIP sequence changes and expression were studied in FIPA and sporadic adenomas. The function of normal and mutated AIP molecules was studied on cell proliferation and protein-protein interaction. Cellular and ultrastructural AIP localization was determined in pituitary cells. PATIENTS: Twenty-six FIPA kindreds and 85 sporadic pituitary adenoma patients were included in the study. RESULTS: Nine families harbored AIP mutations. Overexpression of wild-type AIP in TIG3 and HEK293 human fibroblast and GH3 pituitary cell lines dramatically reduced cell proliferation, whereas mutant AIP lost this ability. All the mutations led to a disruption of the protein-protein interaction between AIP and phosphodiesterase-4A5. In normal pituitary, AIP colocalizes exclusively with GH and prolactin, and it is found in association with the secretory vesicle, as shown by double-immunofluorescence and electron microscopy staining. In sporadic pituitary adenomas, however, AIP is expressed in all tumor types. In addition, whereas AIP is expressed in the secretory vesicle in GH-secreting tumors, similar to normal GH-secreting cells, in lactotroph, corticotroph, and nonfunctioning adenomas, it is localized to the cytoplasm and not in the secretory vesicles. CONCLUSIONS: Our functional evaluation of AIP mutations is consistent with a tumor-suppressor role for AIP and its involvement in familial acromegaly. The abnormal expression and subcellular localization of AIP in sporadic pituitary adenomas indicate deranged regulation of this protein during tumorigenesis.


Assuntos
Adenoma/genética , Neoplasias Hipofisárias/genética , Proteínas/fisiologia , Acromegalia/genética , Acromegalia/metabolismo , Adenoma/metabolismo , Adolescente , Adulto , Idoso , Proliferação de Células , Criança , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Testes Genéticos , Hormônio do Crescimento Humano/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/metabolismo , Ligação Proteica , Proteínas/genética , Proteínas/metabolismo , Transfecção , Células Tumorais Cultivadas
12.
Clin Endocrinol (Oxf) ; 65(3): 389-95, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16918962

RESUMO

OBJECTIVE: It has been reported that both normal pituitary and pituitary tumours express PPAR-gamma, a nuclear hormone receptor, the expression being more abundant in pituitary tumours, and that this is the basis for the reported antiproliferative effects of the thiazolidinedione, rosiglitazone, in animal models. However, the mechanisms for the responsivity to rosiglitazone have remained unclear. DESIGN AND MEASUREMENTS: To investigate this further, 'real-time' PCR was used to assess PPAR-gamma mRNA expression, and Western blotting and immunohistochemistry to study its protein expression, in 46 human pituitary tumours and normal pituitary tissue. Cell proliferation of the GH3 pituitary cell line was assessed by [3H]-thymidine-incorporation after 48 h rosiglitazone and pioglitazone (10(-4) M- 10(-10) M) treatment alone, or rosiglitazone in combination with the PPAR-gamma antagonist GW9662. RESULTS: PPAR-gamma mRNA and protein was found to be expressed in normal pituitary and was variably expressed in pituitary tumours, but were increased specifically in nonfunctioning pituitary adenomas. However, very little staining was observed with immunohistochemistry, with only occasional cell nuclei stained, and no difference was detectable between controls and tumours. Rosiglitazone at 10(-4) M and 10(-5) M concentrations inhibited cell proliferation (10(-4) M 14.0% +/- 1.5% and 10(-5) M 67% +/- 4%[mean +/- SEM]vs Control 100% +/- 3%, P < 0.0001) while lower concentrations showed no significant effect. Following withdrawal of rosiglitazone 10(-5) M, the cells fully recovered at a further 48 h, while lower doses showed a 'rebound' of stimulation. Pioglitazone was of similar potency to rosiglitazone in inhibiting proliferation. The PPAR-gamma antagonist did not show a significant reversal of the antiproliferative effect of rosiglitazone, and indeed suppressed proliferation on its own. CONCLUSIONS: Our data suggest that the antiproliferative action of rosiglitazone is probably not via PPAR-gamma.


Assuntos
Adenoma/química , PPAR gama/análise , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Neoplasias Hipofisárias/química , Tiazolidinedionas/farmacologia , Adenoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Sequência de Bases , Estudos de Casos e Controles , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Imuno-Histoquímica/métodos , Pessoa de Meia-Idade , Dados de Sequência Molecular , PPAR gama/genética , Pioglitazona , Neoplasias Hipofisárias/patologia , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rosiglitazona , Tiazolidinedionas/metabolismo
13.
Eur J Endocrinol ; 153(1): 143-51, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15994756

RESUMO

OBJECTIVES: Microarray technology allows for the expression profile of many thousands of genes to be quantified at the same time, and has resulted in novel discoveries about the tumour biology of a number of cancers. We sought to do this in pituitary adenomas, the most common intracranial neoplasm. METHODS: Affymetrix GeneChip HG-U133A oligonucleotide arrays covering 14 500 well-characterised genes from the human genome were used to study pooled RNA for each of the four major pituitary adenoma subtypes. Individual gene-expression levels in the tumours were compared relative to the expression profile in normal pooled pituitary RNA. Three differentially expressed genes with potential importance in tumourigenesis were chosen for validation by real-time quantitative PCR on the original tumours and on an additional 26 adenomas. RESULTS: Bioinformatic analysis showed that 3906 genes and 351 expressed sequence tags were differentially expressed among all pituitary tumour subtypes. Lysosomal-associated protein transmembrane- 4-beta (LAPTM4B), a novel gene upregulated in hepatocellular carcinoma, was significantly over-expressed in adrenocorticotrophin (ACTH)-secreting adenomas and non-functioning pituitary adenomas (NFPAs). Bcl-2-associated athanogene (BAG1), an anti-apoptotic protein found at high levels in a number of human cancers, was significantly over-expressed in growth hormone-secreting and prolactin-secreting adenomas and NFPAs. The cyclin-dependent kinase inhibitor p18, in which murine gene deletion has been shown to produce pituitary ACTH cell hyperplasia and adenomas, was significantly under-expressed in ACTH-secreting adenomas. CONCLUSIONS: Expression array analysis of pituitary adenomas using the Affymetrix GeneChip HG-U133A arrays appears to be a valid method of identifying genes that may be important in tumour pathogenesis.


Assuntos
Adenoma/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias Hipofisárias/genética , Adenoma/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Proteínas de Ciclo Celular/genética , Inibidor de Quinase Dependente de Ciclina p18 , Proteínas de Ligação a DNA , Humanos , Técnicas In Vitro , Proteínas de Membrana/genética , Proteínas Oncogênicas/genética , Neoplasias Hipofisárias/metabolismo , Reação em Cadeia da Polimerase , Prolactina/metabolismo , Fatores de Transcrição , Proteínas Supressoras de Tumor/genética
14.
Front Horm Res ; 32: 34-62, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15281339

RESUMO

The cell cycle is the process by which cells grow, replicate their genome and divide. The cell cycle control system is a cyclically-operating biochemical device constructed from a set of interacting proteins that induce and coordinate proper progression through the cycle, and includes cyclins, cyclin-dependent kinases (CDK) and their inhibitors (CDKI). There are mainly two families of CDKI, the INK family (INK4a/p16; INK4b/p15; INK4c/p18 and INK4d/p19) and the WAF/KIP family (WAF1/p21; KIP1/p27; KIP2/p57). Progression through the cell cycle is mainly dependent on fluctuations in the concentration of cyclins and CDKI achieved through the programmed degradation of these proteins by proteolysis within the ubiquitin-proteasome system. There is also a transcriptional regulation of cyclin expression, probably dependent on CDK phosphorylation. The p53 family--p53, p63 and p73--function as transcription factors that play a major role in regulating the response of mammalian cells to stressors and damage, in part through the transcriptional activation of genes involved in cell cycle control (e.g. p21), DNA repair, senescence, angiogenesis and apoptosis. Essential for the maintenance of euploidy during mitosis is human securin, identical to the product of the pituitary tumour-transforming gene (PTTG). Loss of regulation at the G1/S transition appears to be a common event among virtually all types of human tumours. Aberrations of one or more components of the pRb/p16/cyclin D1/CDK4 pathway seem to be a frequent event (80%) in pituitary tumours. The role of p27 is rather that of a haploinsufficient gene. p27-/- mice show an increased growth rate, due to increased cellularity, testicular and ovarian cell hyperplasia and infertility, and hyperplasia of the pituitary intermediate lobe with nearly 100% mortality caused by such a benign pituitary tumour. Although the p27 gene was not found to be mutated in human pituitary tumours and its mRNA expression was similar in tumour samples in comparison with normal pituitaries, the load of p27 protein expression in corticotroph adenomas and pituitary carcinomas was shown to be much lower than those in normal pituitary tissue or other types of pituitary adenoma, suggesting that post-translational processing of p27 accelerates its removal from the nucleus. In respect to p27 degradation and its cellular compartmentalization, several pathways have been explored. Malignant tumours are associated with increased nuclear immunostaining for Jun-activation binding protein-1 (Jab1) which is responsible for phosphorylated p27 export from the nucleus. Corticotrophinomas are characterized by massively increased phosphorylation of p27 on Thr187, but are not associated with changes in Jab1. Macrophage inhibitory factor (MIF), which binds and inactivates Jab1, was noted to be over-expressed in tumours with abundant Jab1, suggesting that it may be part of a compensatory mechanism to moderate Jab1 activity. Proteasomal degradation of p27 requires its ubiquitylation by the SCF ubiquitin ligase, with specific addressing by the F-box protein Skp2 and its co-factor Cks1. Pituitary tumours with high p27 protein expression showed significantly less Skp2 expression than samples with low p27 immunostaining, suggesting that increased Skp2 could play at least a part in this process. No difference was observed in Cks1 mRNA levels between normal pituitaries and pituitary adenomas. The present data suggest that inhibition of growth and tumour development is sensitive not only to the absolute levels of p27 protein, but also to its cellular compartmentalization. Very recent findings from our group have established up-regulation of the serine-threonine kinase Akt in pituitary tumours compared to normal pituitary, which may cause phosphorylation of p27 on Thr157 and cytoplasmic retention of p27. PTTG protein is highly expressed in various human tumours, including pituitary tumours. While its mRNA levels are low in normal pituitary, increases in PTTG transcripts from more than 50% to more than 10-fold were recorded in the majority of a series of pituitary adenomas. Control of the cell cycle is a vital part of the cell's replication machinery. Disruption of this process is commonly seen in pituitary tumours and we are now beginning to identify regulatory elements which are likely to play a major role in pituitary oncogenesis.


Assuntos
Ciclo Celular , Neoplasias Hipofisárias/etiologia , Neoplasias Hipofisárias/patologia , Animais , Humanos , Proteínas de Neoplasias/metabolismo , Neoplasias Hipofisárias/metabolismo
15.
Pituitary ; 5(4): 235-42, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-14558671

RESUMO

The CDK inhibitor p27 plays a pivotal role in controlling cell proliferation during development, and has been implicated in tumorigenesis. Previous studies have demonstrated changes in p27 protein expression, but not in mRNA levels, in human pituitary tumors. It seems probable that the fall in p27 is due to increased degradation through the ubiquitin-proteasome pathway. Skp2 (S-phase kinase-interacting protein) is a specific F-box protein that allows the recognition and binding of phosphorylated p27 to the ubiquitin complex. The aim of our study was thus to investigate the possible role of Skp2 in pituitary tumorigenesis. A total of 59 human pituitary samples, 7 normal and 52 adenomas, were assessed for transcriptional expression of Skp2; 51 pituitary samples were assessed for protein expression. Real-time RT-PCR was performed on cDNA of reverse-transcribed mRNA for relative quantification of the Skp2 transcript. Immunostaining was performed using mouse monoclonal anti-Skp2 antibody. Skp2 mRNA and protein was detectable in every sample studied. Our results showed no significant difference between the pituitary tumors and normal pituitary tissue in Skp2 mRNA or nuclear protein expression. Individual tumor types had similar mRNA expression and variable protein expression. However, samples with high p27 protein expression showed significantly less Skp2 expression than samples with low p27 staining. Our data suggest that increased p27 degradation through the ubiquitin-proteasome pathway could be regulated in pituitary tumors by changes in Skp2 expression, although other factors probably also play a role.


Assuntos
Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Regulação Neoplásica da Expressão Gênica/genética , Proteínas dos Microfilamentos/biossíntese , Proteínas dos Microfilamentos/genética , Proteínas Musculares , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/metabolismo , Adenoma/genética , Adenoma/metabolismo , Adenoma/patologia , Adulto , Idoso , Primers do DNA , DNA Complementar/biossíntese , DNA Complementar/genética , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Prolactinoma/genética , Prolactinoma/metabolismo , Prolactinoma/patologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas Quinases Associadas a Fase S
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