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1.
J Biol Chem ; 300(5): 107232, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537696

RESUMO

Cholesterol is essential for both normal cell viability and cancer cell proliferation. Aberrant activity of squalene monooxygenase (SM, also known as squalene epoxidase), the rate-limiting enzyme of the committed cholesterol synthesis pathway, is accordingly implicated in a growing list of cancers. We previously reported that hypoxia triggers the truncation of SM to a constitutively active form, thus preserving sterol synthesis during oxygen shortfalls. Here, we show SM truncation is upregulated and correlates with the magnitude of hypoxia in endometrial cancer tissues, supporting the in vivo relevance of our earlier work. To further investigate the pathophysiological consequences of SM truncation, we examined its lipid droplet-localized pool using complementary immunofluorescence and cell fractionation approaches and found that it exclusively comprises the truncated enzyme. This partitioning is facilitated by the loss of an endoplasmic reticulum-embedded region at the SM N terminus, whereas the catalytic domain containing membrane-associated C-terminal helices is spared. Moreover, we determined multiple amphipathic helices contribute to the lipid droplet localization of truncated SM. Taken together, our results expand on the striking differences between the two forms of SM and suggest upregulated truncation may contribute to SM-related oncogenesis.


Assuntos
Colesterol , Neoplasias do Endométrio , Gotículas Lipídicas , Esqualeno Mono-Oxigenase , Feminino , Humanos , Linhagem Celular Tumoral , Colesterol/metabolismo , Colesterol/biossíntese , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/genética , Retículo Endoplasmático/metabolismo , Regulação Neoplásica da Expressão Gênica , Gotículas Lipídicas/metabolismo , Esqualeno Mono-Oxigenase/metabolismo , Esqualeno Mono-Oxigenase/genética , Regulação para Cima
2.
Clin Sci (Lond) ; 138(4): 173-187, 2024 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-38315575

RESUMO

Semaglutide is an anti-diabetes and weight loss drug that decreases food intake, slows gastric emptying, and increases insulin secretion. Patients begin treatment with low-dose semaglutide and increase dosage over time as efficacy plateaus. With increasing dosage, there is also greater incidence of gastrointestinal side effects. One reason for the plateau in semaglutide efficacy despite continued low food intake is due to compensatory actions whereby the body becomes more metabolically efficient to defend against further weight loss. Mitochondrial uncoupler drugs decrease metabolic efficiency, therefore we sought to investigate the combination therapy of semaglutide with the mitochondrial uncoupler BAM15 in diet-induced obese mice. Mice were fed high-fat western diet (WD) and stratified into six treatment groups including WD control, BAM15, low-dose semaglutide without or with BAM15, and high-dose semaglutide without or with BAM15. Combining BAM15 with either semaglutide dose decreased body fat and liver triglycerides, which was not achieved by any monotherapy, while high-dose semaglutide with BAM15 had the greatest effect on glucose homeostasis. This study demonstrates a novel approach to improve weight loss without loss of lean mass and improve glucose control by simultaneously targeting energy intake and energy efficiency. Such a combination may decrease the need for semaglutide dose escalation and hence minimize potential gastrointestinal side effects.


Assuntos
Ingestão de Energia , Redução de Peso , Humanos , Animais , Camundongos , Camundongos Obesos , Dieta Hiperlipídica/efeitos adversos , Tecido Adiposo
3.
Bioorg Chem ; 151: 107665, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39094508

RESUMO

Compared to normal cells, tumour cells exhibit an upregulation of glucose transporters and an increased rate of glycolytic activity. In previous research, we successfully identified a promising hit compound BH10 through a rigorous screening process, which demonstrates a potent capacity for inhibiting cancer cell proliferation by targeting glucose metabolism. In the current study, we identify Kelch-like ECH-associated protein 1 (Keap1) as a potential protein target of BH10via avidin pull-down assays with biotinylated-BH10. Subsequently, we present a comprehensive analysis of a series of BH10 analogues characterized by the incorporation of a naphthoimidazole scaffold and the introduction of a triazole ring with diverse terminal functional groups. Notably, compound 4d has emerged as the most potent candidate, exhibiting better anti-cancer activities against HEC1A cancer cells with an IC50 of 2.60 µM, an extended biological half-life, and an improved pharmacokinetic profile (compared to BH10) in mice.


Assuntos
Antineoplásicos , Proliferação de Células , Relação Dose-Resposta a Droga , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Glucose , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Humanos , Proliferação de Células/efeitos dos fármacos , Animais , Glucose/metabolismo , Glucose/antagonistas & inibidores , Relação Estrutura-Atividade , Estrutura Molecular , Camundongos , Linhagem Celular Tumoral
4.
Mol Cell ; 57(3): 537-51, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25658205

RESUMO

Ras is mutated in up to 30% of cancers, including 90% of pancreatic ductal adenocarcinomas, causing it to be constitutively GTP-bound, and leading to activation of downstream effectors that promote a tumorigenic phenotype. As targeting Ras directly is difficult, there is a significant effort to understand the downstream biological processes that underlie its protumorigenic activity. Here, we show that expression of oncogenic Ras or direct activation of the MAPK pathway leads to increased mitochondrial fragmentation and that blocking this phenotype, through knockdown of the mitochondrial fission-mediating GTPase Drp1, inhibits tumor growth. This fission is driven by Erk2-mediated phosphorylation of Drp1 on Serine 616, and both this phosphorylation and mitochondrial fragmentation are increased in human pancreatic cancer. Finally, this phosphorylation is required for Ras-associated mitochondrial fission, and its inhibition is sufficient to block xenograft growth. Collectively, these data suggest mitochondrial fission may be a target for treating MAPK-driven malignancies.


Assuntos
GTP Fosfo-Hidrolases/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Dinâmica Mitocondrial , Proteínas Mitocondriais/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Neoplasias Pancreáticas/metabolismo , Animais , Benzamidas/farmacologia , Linhagem Celular Tumoral , Difenilamina/análogos & derivados , Difenilamina/farmacologia , Dinaminas , GTP Fosfo-Hidrolases/genética , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Nus , Proteínas Associadas aos Microtúbulos/genética , Dinâmica Mitocondrial/efeitos dos fármacos , Proteínas Mitocondriais/genética , Neoplasias Experimentais/metabolismo , Fosforilação , Serina/metabolismo , Proteínas ras/metabolismo
5.
Glycobiology ; 32(7): 588-599, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35312763

RESUMO

Neuroblastoma is a highly metastatic childhood cancer for which studies indicate an association between protein glycosylation and tumor behavior. However, there is a lack of detailed glycome analysis on neuroblastoma cells that have varying metastatic potential. Furthermore, the impact of the cell culturing mode, i.e. 2-dimensional (2D) versus 3-dimensional (3D) spheroids, on the membrane protein glycome is unknown. To address these gaps in knowledge, we mapped membrane protein N- and O-glycosylation of neuroblastoma cells that have lower invasive and metastatic potential (Stathmin shRNA-expressing cells, StmnSeq2SH, and StmnSeq3SH) compared with control cells (control shRNA-expressing cells, CtrlSH). We showed that the neuroblastoma cells with different migratory and invasive potential underwent drastic changes in their membrane protein N-glycosylation exclusively when cultured in 3D spheroids. We also investigated the impact of 2D and 3D cell culture methods on cellular glycosylation using the neuroblastoma cells and found the cell N-glycome was markedly impacted by the culture method, with the 2D grown cells showing an abundance of oligomannosidic glycans, whereas 3D spheroids expressed more complex type glycans on their membrane proteins. In summary, this study provides the first comprehensive protein glycome profiling of neuroblastoma cells that have varying invasiveness and migratory potential and unravels the distinct membrane glycan features of cells that are grown under 2D versus 3D culture conditions.


Assuntos
Neuroblastoma , Linhagem Celular Tumoral , Criança , Humanos , Proteínas de Membrana , Neuroblastoma/genética , Neuroblastoma/patologia , Polissacarídeos , RNA Interferente Pequeno
6.
Circ Res ; 127(7): 877-892, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32564710

RESUMO

RATIONALE: Treatment efficacy for diabetes mellitus is largely determined by assessment of HbA1c (glycated hemoglobin A1c) levels, which poorly reflects direct glucose variation. People with prediabetes and diabetes mellitus spend >50% of their time outside the optimal glucose range. These glucose variations, termed transient intermittent hyperglycemia (TIH), appear to be an independent risk factor for cardiovascular disease, but the pathological basis for this association is unclear. OBJECTIVE: To determine whether TIH per se promotes myelopoiesis to produce more monocytes and consequently adversely affects atherosclerosis. METHODS AND RESULTS: To create a mouse model of TIH, we administered 4 bolus doses of glucose at 2-hour intervals intraperitoneally once to WT (wild type) or once weekly to atherosclerotic prone mice. TIH accelerated atherogenesis without an increase in plasma cholesterol, seen in traditional models of diabetes mellitus. TIH promoted myelopoiesis in the bone marrow, resulting in increased circulating monocytes, particularly the inflammatory Ly6-Chi subset, and neutrophils. Hematopoietic-restricted deletion of S100a9, S100a8, or its cognate receptor Rage prevented monocytosis. Mechanistically, glucose uptake via GLUT (glucose transporter)-1 and enhanced glycolysis in neutrophils promoted the production of S100A8/A9. Myeloid-restricted deletion of Slc2a1 (GLUT-1) or pharmacological inhibition of S100A8/A9 reduced TIH-induced myelopoiesis and atherosclerosis. CONCLUSIONS: Together, these data provide a mechanism as to how TIH, prevalent in people with impaired glucose metabolism, contributes to cardiovascular disease. These findings provide a rationale for continual glucose control in these patients and may also suggest that strategies aimed at targeting the S100A8/A9-RAGE (receptor for advanced glycation end products) axis could represent a viable approach to protect the vulnerable blood vessels in diabetes mellitus. Graphic Abstract: A graphic abstract is available for this article.


Assuntos
Aterosclerose/etiologia , Glicemia/metabolismo , Hiperglicemia/complicações , Monócitos/metabolismo , Mielopoese , Neutrófilos/metabolismo , Animais , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/patologia , Biomarcadores/sangue , Calgranulina A/genética , Calgranulina A/metabolismo , Calgranulina B/genética , Calgranulina B/metabolismo , Dieta Hiperlipídica , Modelos Animais de Doenças , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Glicólise , Hiperglicemia/sangue , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Monócitos/patologia , Neutrófilos/patologia , Placa Aterosclerótica , Receptor para Produtos Finais de Glicação Avançada/genética , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Transdução de Sinais
7.
Cell Mol Life Sci ; 78(21-22): 7025-7041, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34626204

RESUMO

Hepatocellular carcinoma (HCC) is one of the most difficult cancer types to treat. Liver cancer is often diagnosed at late stages and therapeutic treatment is frequently accompanied by development of multidrug resistance. This leads to poor outcomes for cancer patients. Understanding the fundamental molecular mechanisms leading to liver cancer development is crucial for developing new therapeutic approaches, which are more efficient in treating cancer. Mice with a liver specific UDP-glucose ceramide glucosyltransferase (UGCG) knockout (KO) show delayed diethylnitrosamine (DEN)-induced liver tumor growth. Accordingly, the rationale for our study was to determine whether UGCG overexpression is sufficient to drive cancer phenotypes in liver cells. We investigated the effect of UGCG overexpression (OE) on normal murine liver (NMuLi) cells. Increased UGCG expression results in decreased mitochondrial respiration and glycolysis, which is reversible by treatment with EtDO-P4, an UGCG inhibitor. Furthermore, tumor markers such as FGF21 and EPCAM are lowered following UGCG OE, which could be related to glucosylceramide (GlcCer) and lactosylceramide (LacCer) accumulation in glycosphingolipid-enriched microdomains (GEMs) and subsequently altered signaling protein phosphorylation. These cellular processes lead to decreased proliferation in NMuLi/UGCG OE cells. Our data show that increased UGCG expression itself does not induce pro-cancerous processes in normal liver cells, which indicates that increased GlcCer expression leads to different outcomes in different cancer types.


Assuntos
Biomarcadores Tumorais/metabolismo , Metabolismo Energético/fisiologia , Glucosilceramidas/metabolismo , Fígado/metabolismo , Animais , Carcinoma Hepatocelular/metabolismo , Linhagem Celular , Resistência a Múltiplos Medicamentos/fisiologia , Glucosiltransferases/metabolismo , Glicólise/fisiologia , Glicoesfingolipídeos/metabolismo , Neoplasias Hepáticas/metabolismo , Camundongos , Mitocôndrias/metabolismo , Transdução de Sinais/fisiologia
8.
Int J Mol Sci ; 23(9)2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35562868

RESUMO

Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer. Low numbers of HCC patients being suitable for liver resection or transplantation and multidrug resistance development during pharmacotherapy leads to high death rates for HCC patients. Understanding the molecular mechanisms of HCC etiology may contribute to the development of novel therapeutic strategies for prevention and treatment of HCC. UDP-glucose ceramide glycosyltransferase (UGCG), a key enzyme in glycosphingolipid metabolism, generates glucosylceramide (GlcCer), which is the precursor for all glycosphingolipids (GSLs). Since UGCG gene expression is altered in 0.8% of HCC tumors, GSLs may play a role in cellular processes in liver cancer cells. Here, we discuss the current literature about GSLs and their abundance in normal liver cells, Gaucher disease and HCC. Furthermore, we review the involvement of UGCG/GlcCer in multidrug resistance development, globosides as a potential prognostic marker for HCC, gangliosides as a potential liver cancer stem cell marker, and the role of sulfatides in tumor metastasis. Only a limited number of molecular mechanisms executed by GSLs in HCC are known, which we summarize here briefly. Overall, the role GSLs play in HCC progression and their ability to serve as biomarkers or prognostic indicators for HCC, requires further investigation.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/genética , Resistência a Múltiplos Medicamentos , Glucosilceramidas/metabolismo , Glucosiltransferases/metabolismo , Glicoesfingolipídeos/metabolismo , Glicosiltransferases/metabolismo , Humanos , Neoplasias Hepáticas/genética
9.
Int J Mol Sci ; 23(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36232772

RESUMO

Endometrial cancer is the most common gynaecological malignancy in developed countries. One of the largest risk factors for endometrial cancer is obesity. The aim of this study was to determine whether there are differences in the transcriptome of endometrial cancers from obese vs. lean women. Here we investigate the transcriptome of endometrial cancer between obese and lean postmenopausal women using rRNA-depleted RNA-Seq data from endometrial cancer tissues and matched adjacent non-cancerous endometrial tissues. Differential expression analysis identified 12,484 genes (6370 up-regulated and 6114 down-regulated) in endometrial cancer tissues from obese women, and 6219 genes (3196 up-regulated and 3023 down-regulated) in endometrial cancer tissues from lean women (adjusted p-value < 0.1). A gene ontology enrichment analysis revealed that the top 1000 up-regulated genes (by adjusted p-value) were enriched for growth and proliferation pathways while the top 1000 down-regulated genes were enriched for cytoskeleton restructure networks in both obese and lean endometrial cancer tissues. In this study, we also show perturbations in the expression of protein coding genes (HIST1H2BL, HIST1H3F, HIST1H2BH, HIST1H1B, TTK, PTCHD1, ASPN, PRELP, and CDH13) and the lncRNA MBNL1-AS1 in endometrial cancer tissues. Overall, this study has identified gene expression changes that are similar and also unique to endometrial cancers from obese vs. lean women. Furthermore, some of these genes may serve as prognostic biomarkers or, possibly, therapeutic targets for endometrial cancer.


Assuntos
Neoplasias do Endométrio , Obesidade , RNA Longo não Codificante , Magreza , Transcriptoma , Biomarcadores/metabolismo , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/metabolismo , Feminino , Humanos , Obesidade/genética , Obesidade/metabolismo , RNA Longo não Codificante/genética , Magreza/genética , Magreza/metabolismo
10.
Int J Mol Sci ; 23(17)2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36077188

RESUMO

Obesity-related insulin resistance is a highly prevalent and growing health concern, which places stress on the pancreatic islets of Langerhans by increasing insulin secretion to lower blood glucose levels. The glucose transporters GLUT1 and GLUT3 play a key role in glucose-stimulated insulin secretion in human islets, while GLUT2 is the key isoform in rodent islets. However, it is unclear whether other glucose transporters also contribute to insulin secretion by pancreatic islets. Herein, we show that SLC2A6 (GLUT6) is markedly upregulated in pancreatic islets from genetically obese leptin-mutant (ob/ob) and leptin receptor-mutant (db/db) mice, compared to lean controls. Furthermore, we observe that islet SLC2A6 expression positively correlates with body mass index in human patients with type 2 diabetes. To investigate whether GLUT6 plays a functional role in islets, we crossed GLUT6 knockout mice with C57BL/6 ob/ob mice. Pancreatic islets isolated from ob/ob mice lacking GLUT6 secreted more insulin in response to high-dose glucose, compared to ob/ob mice that were wild type for GLUT6. The loss of GLUT6 in ob/ob mice had no adverse impact on body mass, body composition, or glucose tolerance at a whole-body level. This study demonstrates that GLUT6 plays a role in pancreatic islet insulin secretion in vitro but is not a dominant glucose transporter that alters whole-body metabolic physiology in ob/ob mice.


Assuntos
Diabetes Mellitus Tipo 2 , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Obesidade/metabolismo , Animais , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Proteínas Facilitadoras de Transporte de Glucose/genética , Humanos , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos
11.
J Immunol ; 202(6): 1826-1832, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30700586

RESUMO

The polarization processes for M1 versus M2 macrophages are quite distinct in the context of changes in cellular metabolism. M1 macrophages are highly glycolytic, whereas M2 macrophages require a more oxidative nutrient metabolism. An important part of M1 polarization involves upregulation of the glucose transporter (GLUT) GLUT1 to facilitate increased glucose uptake and glycolytic metabolism; however, the role of other glucose transporters in this process is largely unknown. In surveying the Functional Annotation of the Mammalian Genome and Gene Expression Omnibus Profiles databases, we discovered that the glucose transporter GLUT6 is highly upregulated in LPS-activated macrophages. In our previous work, we have not detected mouse GLUT6 protein expression in any noncancerous tissue; therefore, in this study, we investigated the expression and significance of GLUT6 in bone marrow-derived macrophages from wild-type and GLUT6 knockout C57BL/6 mice. We show that LPS-induced M1 polarization markedly upregulated GLUT6 protein, whereas naive macrophages and IL-4-induced M2 macrophages do not express GLUT6 protein. However, despite strong upregulation of GLUT6 in M1 macrophages, the absence of GLUT6 did not alter M1 polarization in the context of glucose uptake, glycolytic metabolism, or cytokine production. Collectively, these data show that GLUT6 is dispensable for LPS-induced M1 polarization and function. These findings are important because GLUT6 is an anticancer drug target, and this study suggests that inhibition of GLUT6 may not impart detrimental side effects on macrophage function to interfere with their antitumor properties.


Assuntos
Diferenciação Celular/imunologia , Proteínas Facilitadoras de Transporte de Glucose/imunologia , Proteínas Facilitadoras de Transporte de Glucose/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Animais , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Knockout
13.
J Enzyme Inhib Med Chem ; 34(1): 728-739, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30822267

RESUMO

The most challenging issue facing peptide drug development is producing a molecule with optimal physical properties while maintaining target binding affinity. Masking peptides with protecting groups that can be removed inside the cell, produces a cell-permeable peptide, which theoretically can maintain its biological activity. Described are series of prodrugs masked using: (a) O-alkyl, (b) N-alkyl, and (c) acetyl groups, and their binding affinity for Hsp90. Alkyl moieties increased compound permeability, Papp, from 3.3 to 5.6, however alkyls could not be removed by liver microsomes or in-vivo and their presence decreased target binding affinity (IC50 of ≥10 µM). Thus, unlike small molecules, peptide masking groups cannot be predictably removed; their removal is related to the 3-D conformation. O-acetyl groups were cleaved but are labile, increasing challenges during synthesis. Utilising acetyl groups coupled with mono-methylated amines may decrease the polarity of a peptide, while maintaining binding affinity.


Assuntos
Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Peptídeos Cíclicos/farmacologia , Pró-Fármacos/farmacologia , Animais , Relação Dose-Resposta a Droga , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Camundongos , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Estrutura Molecular , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Pró-Fármacos/química , Pró-Fármacos/metabolismo , Relação Estrutura-Atividade
14.
Am J Physiol Endocrinol Metab ; 315(2): E286-E293, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29664675

RESUMO

Glucose transporter 6 (GLUT6) is a member of the facilitative glucose transporter family. GLUT6 is upregulated in several cancers but is not widely expressed in normal tissues. Previous studies have shown that GLUT6 knockdown kills endometrial cancer cells that express elevated levels of the protein. However, whether GLUT6 represents a viable anticancer drug target is unclear because the role of GLUT6 in normal metabolic physiology is unknown. Herein we generated GLUT6 knockout mice to determine how loss of GLUT6 affected whole body glucose homeostasis and metabolic physiology. We found that the mouse GLUT6 ( Slc2a6) gene expression pattern was similar to humans with mRNA found primarily in brain and spleen. CRISPR-Cas9-mediated deletion of Slc2a6 did not alter mouse development, growth, or whole body glucose metabolism in male or female mice fed either a chow diet or Western diet. GLUT6 deletion did not impact glucose tolerance or blood glucose and insulin levels in male or female mice fed either diet. However, compared with wild-type littermate controls, GLUT6 null female mice had a relatively minor decrease in fat accumulation when fed Western diet and had a lower respiratory exchange ratio when fed chow diet. Collectively, these data show that GLUT6 is not a major regulator of whole body metabolic physiology; therefore, GLUT6 inhibition may have minimal adverse effects if targeted for cancer therapy.


Assuntos
Proteínas Facilitadoras de Transporte de Glucose/genética , Metabolismo/genética , Metabolismo/fisiologia , Adiposidade/genética , Animais , Glicemia/metabolismo , Peso Corporal/genética , Sistemas CRISPR-Cas , Dieta , Metabolismo Energético/genética , Feminino , Genótipo , Glucose/metabolismo , Teste de Tolerância a Glucose , Homeostase/genética , Insulina/sangue , Masculino , Camundongos , Camundongos Knockout
15.
Gynecol Oncol ; 147(3): 654-662, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29050779

RESUMO

Endometrial cancer is the most common gynecological malignancy in the developed world. It is the fifth most common cancer and accounts for 4.8% of all cancers in women. Long intergenic non-coding RNAs (lincRNAs), a subclass of long non-coding RNAs, are pervasively transcribed throughout the human genome. OBJECTIVE: LincRNA expression patterns in endometrial cancer compared to normal healthy tissue are poorly characterised. In this study, the lincRNA transcriptome of endometrial cancers and adjacent normal endometrium from the same patients was sequenced and compared with transcriptomes of other gynaecologic malignancies including ovarian and cervical cancers. METHODS: RNA was isolated from malignant and adjacent non-affected endometrial tissue from 6 patients with low grade and stage Type I endometrial cancer. Subsequently, Illumina paired-end RNA sequencing was performed, followed by bioinformatics analysis, to determine differential transcriptome expression patterns. RESULTS: LINC00958 was upregulated in all three cancers, and four lincRNAs including LINC01480, LINC00645, LINC00891 and LINC00702 demonstrated exquisite specificity for malignant endometrium compared to normal endometrium while also distinguishing endometrial cancer from ovarian and cervical cancers. Furthermore, LINC01480 has features required to express a micropeptide. CONCLUSIONS: The lincRNAs, characterised in this study, represent high priority genes to be tested for functional significance in the pathogenesis and/or progression of endometrial cancer. Furthermore, lincRNAs have potential to be released into the bloodstream and therefore the four lincRNAs identified here may represent biomarkers for early detection of endometrial cancer without biopsy.


Assuntos
Neoplasias do Endométrio/genética , RNA Longo não Codificante/genética , Estudos de Casos e Controles , Neoplasias do Endométrio/patologia , Feminino , Humanos , Estadiamento de Neoplasias , Oligopeptídeos/biossíntese , Oligopeptídeos/genética , Especificidade de Órgãos , RNA Neoplásico/genética , Transcriptoma , Regulação para Cima , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/patologia
16.
J Pathol ; 239(1): 3-5, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26880235

RESUMO

Fatty liver, also termed hepatic steatosis or fatty liver disease, is a condition characterized by excess fat accumulation in the liver. Common causes of fatty liver include obesity, ageing, medications, genetic disorders, viral hepatitis, excess alcohol or toxins. This diversity in pathogenesis is matched by an equally diverse spectrum of consequences, whereby some individuals remain asymptomatic yet others progress through a series of inflammatory, fibrotic and metabolic disorders that can lead to liver failure, cancer or diabetes. Current treatment approaches for fatty liver do not differ by disease aetiology and primarily involve weight loss strategies or management of co-morbidities. In a recent paper published in this journal, Urasaki et al used capillary isoelectric focusing (cIEF) to create profiles of protein post-translational modifications that distinguish four different models of fatty liver in mice. Importantly, this new cIEF approach has the potential to provide rapid individualized diagnosis of fatty liver pathogenesis that may enable more accurate and personalized treatment strategies. Further testing and optimization of cIEF as a diagnostic screening tool in humans is warranted.


Assuntos
Fígado Gorduroso/metabolismo , Ensaios de Triagem em Larga Escala , Fígado/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Proteômica/métodos , Animais
17.
Biochem J ; 471(2): 243-53, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26283546

RESUMO

Null mutations of the Niemann-Pick type C1 (NPC1) gene cause NPC disease, a lysosomal storage disorder characterized by cholesterol accumulation in late endosomes (LE) and lysosomes (Ly). Nascent or mutated NPC1 is degraded through the ubiquitin-proteasome pathway, but how NPC1 degradation is regulated remains currently unknown. In the present study, we demonstrated a link between NPC1 degradation and the Akt (protein kinase B)/mTOR [mammalian (or mechanistic) target of rapamycin] signalling pathway in cervical cancer cell lines. We provided evidence that activated Akt/mTOR pathway increased NPC1 degradation by ∼50% in C33A cells when compared with SiHa or HeLa cells. NPC1 degradation in C33A cells was reversed when Akt/mTOR activation was blocked by specific inhibitors or when mTORC1 (mTOR complex 1) was disrupted by regulatory associated protein of mTOR (Raptor) knockdown. Importantly, inhibition of the Akt/mTOR pathway led to decreased NPC1 ubiquitination in C33A cells, pointing to a role of Akt/mTOR in the proteasomal degradation of NPC1. Moreover, we found that NPC1 depletion in several cancer cell lines inhibited cell proliferation and migration. Our results uncover Akt as a key regulator of NPC1 degradation and link NPC1 to cancer cell proliferation and migration.


Assuntos
Proteínas de Transporte/metabolismo , Colesterol/metabolismo , Glicoproteínas de Membrana/metabolismo , Neoplasias/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas de Transporte/genética , Movimento Celular/genética , Proliferação de Células/genética , Colesterol/genética , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Alvo Mecanístico do Complexo 1 de Rapamicina , Glicoproteínas de Membrana/genética , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo , Neoplasias/genética , Neoplasias/patologia , Proteína C1 de Niemann-Pick , Complexo de Endopeptidases do Proteassoma/genética , Proteínas Proto-Oncogênicas c-akt/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
18.
J Hepatol ; 62(3): 599-606, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25450719

RESUMO

BACKGROUND & AIMS: Mice exposed to the hepatocellular carcinogen diethylnitrosamine at 2 weeks of age have a high risk of developing primary liver tumors later in life. Previous studies have demonstrated that diethylnitrosamine-treated mice have increased tumor burden when fed an obesigenic "Western" diet rich in lard fat and sugar. However, the role of dietary fats vs. sugars in the promotion of liver cancer is poorly understood. The aim of this study was to determine how altering dietary fats vs. sugars affects tumor burden in the diethylnitrosamine model. METHODS: C57BL/6N mice were treated with diethylnitrosamine at 2 weeks of age and, from 6 to 32 weeks of age, fed one of five diets that differed in fat and sugar content, including normal chow, ketogenic, and Western diets. RESULTS: Mice fed sugar-rich diets had the greatest tumor burden irrespective of dietary fat content. In contrast, mice fed a high-fat low-sugar diet had the least tumor burden despite obesity and glucose intolerance. When evaluated as independent variables, tumor burden was positively correlated with hepatic fat accumulation, postprandial insulin, and liver IL-6, and inversely correlated with serum adiponectin. In contrast, tumor burden did not correlate with adiposity, fasting insulin, or glucose intolerance. Furthermore, mice fed high sugar diets had lower liver expression of p21 and cleaved caspase-3 compared to mice fed low sugar diets. CONCLUSIONS: These data indicate that dietary sugar intake contributes to liver tumor burden independent of excess adiposity or insulin resistance in mice treated with diethylnitrosamine.


Assuntos
Carboidratos da Dieta/efeitos adversos , Gorduras na Dieta/efeitos adversos , Dietilnitrosamina/toxicidade , Neoplasias Hepáticas Experimentais/etiologia , Adipocinas/sangue , Adiposidade , Animais , Carcinógenos/toxicidade , Dieta Cetogênica/efeitos adversos , Dieta Ocidental/efeitos adversos , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Feminino , Mediadores da Inflamação/metabolismo , Resistência à Insulina , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Carga Tumoral
19.
Acta Physiol (Oxf) ; 240(10): e14217, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39152636

RESUMO

BACKGROUND AND AIM: Metabolic dysfunction-associated steatohepatitis (MASH) is a metabolic disorder with limited treatment options. The thyroid hormone receptor (THR)-ß agonist resmetirom/MGL-3196 (MGL) increases liver fat oxidation and has been approved for treating adult MASH. However, over 60% of patients receiving MGL treatment do not achieve MASH resolution. Therefore, we investigated the potential for combination therapy of MGL with the mitochondrial uncoupler BAM15 to improve fatty liver disease outcomes in the GAN mouse model of MASH. METHODS: C57BL/6J male mice were fed GAN diet for 38 weeks before stratification and randomization to treatments including MGL, BAM15, MGL + BAM15, or no drug control for 8 weeks. Treatments were admixed in diet and mice were pair-fed to control for drug intake. Treatment effectiveness was assessed by body weight, body composition, energy expenditure, glucose tolerance, tissue lipid content, and histological analyses. RESULTS: MGL + BAM15 treatment resulted in better efficacy versus GAN control mice than either monotherapy in the context of energy expenditure, liver fat loss, glucose control, and fatty liver disease activity score. Improvements in ALT, liver mass, and plasma cholesterol were primarily driven by MGL, while improvements in body fat were primarily driven by BAM15. No treatments altered liver fibrosis. CONCLUSIONS: MGL + BAM15 treatment had overall better efficacy to improve metabolic outcomes in mice fed GAN diet than either monotherapy alone. These data warrant further investigation into combination therapies of THR-ß agonists and mitochondrial uncouplers for the potential treatment of disorders related to fatty liver, obesity, and insulin resistance.


Assuntos
Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Animais , Masculino , Camundongos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/tratamento farmacológico , Fígado/metabolismo , Fígado/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Quimioterapia Combinada , Metabolismo dos Lipídeos/efeitos dos fármacos , Propionatos , Piridazinas , Uracila/análogos & derivados , Chalconas
20.
Biochim Biophys Acta Mol Basis Dis ; 1870(1): 166908, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37793464

RESUMO

Metabolic disorders such as type 2 diabetes, fatty liver disease, hyperlipidemia, and obesity commonly co-occur but clinical treatment options do not effectively target all disorders. Calorie restriction, semaglutide, rosiglitazone, and mitochondrial uncouplers have all demonstrated efficacy against one or more obesity-related metabolic disorders, but it currently remains unclear which therapeutic strategy best targets the combination of hyperglycaemia, liver fat, hypertriglyceridemia, and adiposity. Herein we performed a head-to-head comparison of 5 treatment interventions in the female db/db mouse model of severe metabolic disease. Treatments included ∼60 % calorie restriction (CR), semaglutide, rosiglitazone, BAM15, and niclosamide ethanolamine (NEN). Results showed that BAM15 and CR improved body weight and liver steatosis to levels superior to semaglutide, NEN, and rosiglitazone, while BAM15, semaglutide, and rosiglitazone improved glucose tolerance better than CR and NEN. BAM15, CR, semaglutide, and rosiglitazone all had efficacy against hypertriglyceridaemia. These data provide a comprehensive head-to-head comparison of several key treatment strategies for metabolic disease and highlight the efficacy of mitochondrial uncoupling to correct multiple facets of the metabolic disease milieu in female db/db mice.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Feminino , Niclosamida/uso terapêutico , Rosiglitazona/farmacologia , Rosiglitazona/uso terapêutico , Etanolamina/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Restrição Calórica , Etanolaminas/uso terapêutico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/tratamento farmacológico , Obesidade/metabolismo
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