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1.
Mol Metab ; 34: 174-186, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32180557

RESUMO

OBJECTIVE: It is well established that the liver-specific miR-122, a bona fide tumor suppressor, plays a critical role in lipid homeostasis. However, its role, if any, in amino acid metabolism has not been explored. Since glutamine (Gln) is a critical energy and anaplerotic source for mammalian cells, we assessed Gln metabolism in control wild type (WT) mice and miR-122 knockout (KO) mice by stable isotope resolved metabolomics (SIRM) studies. METHODS: Six-to eight-week-old WT and KO mice and 12- to 15-month-old liver tumor-bearing mice were injected with [U-13C5,15N2]-L-Gln, and polar metabolites from the liver tissues were analyzed by nuclear magnetic resonance (NMR) imaging and ion chromatography-mass spectrometry (IC-MS). Gln-metabolism was also assessed in a Gln-dependent hepatocellular carcinoma (HCC) cell line (EC4). Expressions of glutaminases (Gls and Gls2) were analyzed in mouse livers and human primary HCC samples. RESULTS: The results showed that loss of miR-122 promoted glutaminolysis but suppressed gluconeogenesis in mouse livers as evident from the buildup of 13C- and/or 15N-Glu and decrease in glucose-6-phosphate (G6P) levels, respectively, in KO livers. Enhanced glutaminolysis is consistent with the upregulation of expressions of Gls (kidney-type glutaminase) and Slc1a5, a neutral amino acid transporter in KO livers. Both Gls and Slc1a5 were confirmed as direct miR-122 targets by the respective 3'-UTR-driven luciferase assays. Importantly, expressions of Gls and Slc1a5 as well as glutaminase activity were suppressed in a Gln-dependent HCC (EC4) cell line transfected with miR-122 mimic that resulted in decreased 13C-Gln, 13C-á-ketoglutarate, 13C-isocitrate, and 13C-citrate levels. In contrast, 13C-phosphoenolpyruvate and 13C-G6P levels were elevated in cells expressing ectopic miR-122, suggesting enhanced gluconeogenesis. Finally, The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) database analysis showed that expression of GLS is negatively correlated with miR-122 in primary human HCCs, and the upregulation of GLS RNA is associated with higher tumor grade. More importantly, patients with higher expressions of GLS or SLC1A5 in tumors exhibited poor survival compared with those expressing lower levels of these proteins. CONCLUSIONS: Collectively, these results show that miR-122 modulates Gln metabolism both in vitro and in vivo, implicating the therapeutic potential of miR-122 in HCCs that exhibit relatively high GLS levels.

2.
Mol Cancer Ther ; 19(2): 384-396, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31582534

RESUMO

Hepatocellular carcinoma (HCC), the most prevalent primary liver cancer, is a leading cause of cancer-related death worldwide because of rising incidence and limited therapy. Although treatment with sorafenib or lenvatinib is the standard of care in patients with advanced-stage HCC, the survival benefit from sorafenib is limited due to low response rate and drug resistance. Ibrutinib, an irreversible tyrosine kinase inhibitor (TKI) of the TEC (e.g., BTK) and ErbB (e.g., EGFR) families, is an approved treatment for B-cell malignancies. Here, we demonstrate that ibrutinib inhibits proliferation, spheroid formation, and clonogenic survival of HCC cells, including sorafenib-resistant cells. Mechanistically, ibrutinib inactivated EGFR and its downstream Akt and ERK signaling in HCC cells, and downregulated a set of critical genes involved in cell proliferation, migration, survival, and stemness, and upregulated genes promoting differentiation. Moreover, ibrutinib showed synergy with sorafenib or regorafenib, a sorafenib congener, by inducing apoptosis of HCC cells. In vivo, this TKI combination significantly inhibited HCC growth and prolonged survival of immune-deficient mice bearing human HCCLM3 xenograft tumors and immune-competent mice bearing orthotopic mouse Hepa tumors at a dose that did not exhibit systemic toxicity. In immune-competent mice, the ibrutinib-sorafenib combination reduced the numbers of BTK+ immune cells in the tumor microenvironment. Importantly, we found that the BTK+ immune cells were also enriched in the tumor microenvironment in a subset of primary human HCCs. Collectively, our findings implicate BTK signaling in hepatocarcinogenesis and support clinical trials of the sorafenib-ibrutinib combination for this deadly disease.

4.
Cancer Res ; 79(17): 4326-4330, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31481419

RESUMO

Hepatocellular carcinoma (HCC) has emerged as a major cause of cancer deaths globally. The landscape of systemic therapy has recently changed, with six additional systemic agents either approved or awaiting approval for advanced stage HCC. While these agents have the potential to improve outcomes, a survival increase of 2-5 months remains poor and falls short of what has been achieved in many other solid tumor types. The roles of genomics, underlying cirrhosis, and optimal use of treatment strategies that include radiation, liver transplantation, and surgery remain unanswered. Here, we discuss new treatment opportunities, controversies, and future directions in managing HCC.

9.
Sci Rep ; 8(1): 9105, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29904144

RESUMO

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. Thus, a better understanding of molecular aberrations involved in HCC pathogenesis is necessary for developing effective therapy. It is well established that cancer cells metabolize energy sources differently to rapidly generate biomass. Glucose-6-phosphate-dehydrogenase (G6PD), the rate-limiting enzyme of the Pentose Phosphate Pathway (PPP), is often activated in human malignancies to generate precursors for nucleotide and lipid synthesis. Here, we determined the clinical significance of G6PD in primary human HCC by analyzing RNA-seq and clinical data in The Cancer Genome Atlas. We found that the upregulation of G6PD correlates with higher tumor grade, increased tumor recurrence, and poor patient survival. Notably, liver-specific miR-122, which is essential for metabolic homeostasis, suppresses G6PD expression by directly interacting with its 3'UTR. Luciferase reporter assay confirmed two conserved functional miR-122 binding sites located in the 3'-UTR of G6PD. Furthermore, we show that ectopic expression of miR-122 and miR-1, a known regulator of G6PD expression coordinately repress G6PD expression in HCC cells. These miRNAs also reduced G6PD activity in HepG2 cells that express relatively high activity of this enzyme. Collectively, this study provides evidence that anti-HCC efficacy of miR122 and miR-1 could be mediated, at least in part, through inhibition of PPP by suppressing the expression of G6PD.


Assuntos
Carcinoma Hepatocelular/metabolismo , Glucosefosfato Desidrogenase/biossíntese , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , Proteínas de Neoplasias/biossíntese , RNA Neoplásico/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Glucosefosfato Desidrogenase/genética , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , Proteínas de Neoplasias/genética , RNA Neoplásico/genética , Regulação para Cima
10.
PLoS One ; 13(6): e0198552, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29879168

RESUMO

Hepatocellular carcinoma (HCC) remains one of the major causes of cancer related deaths. Although ultrasonography (US), computed tomography (CT) and/or high-cost magnetic resonance imaging (MRI) have been shown to improve early detection of liver cancer and mortality rates in high-risk individuals, such imaging based methods are limited by high rates of false positivity leading to unnecessary patient anxiety and invasive procedures. Complementary blood biomarkers could increase the accuracy of early detection. Although Alpha-fetoprotein (AFP) in blood is widely used in HCC screening and diagnosis, the false-negative rate as high as 30% and 40% is found in advanced HCC and early stage HCC respectively. We detected AFP messenger RNA (mRNA) in extracellular vesicles (EVs) in patient plasma using designed molecular beacons and a novel tethered lipoplex nanoparticle (TLN) biochip. Together with glypican-3 (GPC-3) mRNA, another well-known HCC marker, we observed much improved performance of AFP protein-based HCC detection. Comparing normal donors (N = 38) and HCC patients (N = 40), our TLN biochip using EV AFP and GPC-3 mRNAs provided an AUC (area under the ROC curve) of 0.995, better than that of a single marker. This 2-mRNA combination also provided a perfect positive predictive value (PPV = 1) at a negative predictive value (NPV) of 0.95 and 20% prevalence, while the blood AFP protein or plasma EV GPC3 mRNA alone could only provide a PPV of 0.61 and 0.79 respectively at the same conditions. Thus, this facile new method may complement current models for risk stratification in liver cancer screening, therapeutic monitoring, and after-treatment surveillance. However, large scale validation will need to be conducted to confirm its clinical potential.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma Hepatocelular/diagnóstico , Detecção Precoce de Câncer/métodos , Vesículas Extracelulares/metabolismo , Neoplasias Hepáticas/diagnóstico , RNA Mensageiro/sangue , Idoso , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/patologia , Vesículas Extracelulares/genética , Estudos de Viabilidade , Feminino , Glipicanas/genética , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Sondas Moleculares/química , Nanopartículas/química , Valor Preditivo dos Testes , RNA Mensageiro/metabolismo , Medição de Risco/métodos , Tomografia Computadorizada por Raios X , Ultrassonografia , alfa-Fetoproteínas/genética
12.
Int J Mol Sci ; 19(3)2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29538313

RESUMO

MicroRNAs are ~22 nucleotide RNAs that regulate gene expression at the post-transcriptional level by binding messenger RNA transcripts. miR-21 is described as an oncomiR whose steady-state levels are commonly increased in many malignancies, including hepatocellular carcinoma (HCC). Methods known as cross-linking and immunoprecipitation of RNA followed by sequencing (CLIP-seq) have enabled transcriptome-wide identification of miRNA interactomes. In our study, we use a publicly available Argonaute-CLIP dataset (GSE97061), which contains nine HCC cases with matched benign livers, to characterize the miR-21 interactome in HCC. Argonaute-CLIP identified 580 miR-21 bound target sites on coding transcripts, of which 332 were located in the coding sequences, 214 in the 3'-untranslated region, and 34 in the 5'-untranslated region, introns, or downstream sequences. We compared the expression of miR-21 targets in 377 patients with liver cancer from the data generated by The Cancer Genome Atlas (TCGA) and found that mRNA levels of 402 miR-21 targets are altered in HCC. Expression of three novel predicted miR-21 targets (CAMSAP1, DDX1 and MARCKSL1) correlated with HCC patient survival. Analysis of RNA-seq data from SK-Hep1 cells treated with a miR-21 antisense oligonucleotide (GSE65892) identified RMND5A, an E3 ubiquitin ligase, as a strong miR-21 candidate target. Collectively, our analysis identified novel miR-21 targets that are likely to play a causal role in hepatocarcinogenesis.


Assuntos
Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/genética , MicroRNAs/genética , Animais , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Redes Reguladoras de Genes , Humanos , Neoplasias Hepáticas/metabolismo , Camundongos , Transcriptoma
17.
Mol Cancer Res ; 16(2): 256-268, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29187559

RESUMO

Hepatocellular carcinoma (HCC) is the most prevalent and highly aggressive liver malignancy with limited therapeutic options. Here, the therapeutic potential of zerumbone, a sesquiterpene derived from the ginger plant Zingiber zerumbet, against HCC was explored. Zerumbone inhibited proliferation and clonogenic survival of HCC cells in a dose-dependent manner by arresting cells at the G2-M phase and inducing apoptosis. To elucidate the underlying molecular mechanisms, a phosphokinase array was performed that showed significant inhibition of the PI3K/AKT/mTOR and STAT3 signaling pathways in zerumbone-treated HCC cells. Gene expression profiling using microarray and analysis of microarray data by Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) revealed that zerumbone treatment resulted in significant deregulation of genes regulating apoptosis, cell cycle, and metabolism. Indeed, tracing glucose metabolic pathways by growing HCC cells with 13C6-glucose and measuring extracellular and intracellular metabolites by 2D nuclear magnetic resonance (NMR) spectroscopy showed a reduction in glucose consumption and reduced lactate production, suggesting glycolytic inhibition. In addition, zerumbone impeded shunting of glucose-6-phosphate through the pentose phosphate pathway, thereby forcing tumor cells to undergo cell-cycle arrest and apoptosis. Importantly, zerumbone treatment suppressed subcutaneous and orthotopic growth and lung metastasis of HCC xenografts in immunocompromised mice. In conclusion, these findings reveal a novel and potentially effective therapeutic strategy for HCC using a natural product that targets cancer cell metabolism.Implications: Dietary compounds, like zerumbone, that impact cell cycle, apoptosis, and metabolic processes may have therapeutic benefits for HCC patients. Mol Cancer Res; 16(2); 256-68. ©2017 AACR.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Glucose/metabolismo , Glicólise/efeitos dos fármacos , Neoplasias Hepáticas/tratamento farmacológico , Sesquiterpenos/administração & dosagem , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Sesquiterpenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Oncotarget ; 8(43): 73757-73765, 2017 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-29088742

RESUMO

Hepatocellular carcinoma (HCC) is a frequent form of cancer with a poor prognosis, and environmental factors significantly contribute to the risk. Despite knowledge that a Western-style diet is a risk factor in the development of nonalcoholic steatohepatitis (NASH) and subsequent progression to HCC, diet-induced signaling changes are not well understood. Understanding molecular mechanisms altered by diet is crucial for developing preventive and therapeutic strategies. We have previously shown that diets enriched with high-fat and high-cholesterol, shown to produce NASH and HCC, induce hepatic protein kinase C beta (PKCß) expression in mice, and a systemic loss of PKCß promotes hepatic cholesterol accumulation in response to this diet. Here, we sought to determine how PKCß and diet functionally interact during the pathogenesis of NASH and how it may promote hepatic carcinogenesis. We found that diet-induced hepatic PKCß expression is accompanied by an increase in phosphorylation of Ser780 of retinoblastoma (RB) protein. Intriguingly, PKCß-/- livers exhibited reduced RB protein levels despite increased transcription of the RB gene. It is also accompanied by reduced RBL-1 with no significant effect on RBL-2 protein levels. We also found reduced expression of the PKCß in HCC compared to non-tumorous liver in human patients. These results raise an interesting possibility that diet-induced PKCß activation represents an important mediator in the functional wiring of cholesterol metabolism and tumorigenesis through modulating stability of cell cycle-associated proteins. The potential role of PKCß in the suppression of tumorigenesis is discussed.

19.
Am J Pathol ; 187(12): 2758-2774, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28963035

RESUMO

Acetaminophen toxicity is a leading cause of acute liver failure (ALF). We found that miRNA-122 (miR-122) is down-regulated in liver biopsy specimens of patients with ALF and in acetaminophen-treated mice. A marked decrease in the primary miR-122 expression occurs in mice on acetaminophen overdose because of suppression of its key transactivators, hepatocyte nuclear factor (HNF)-4α and HNF6. More importantly, the mortality rates of male and female liver-specific miR-122 knockout (LKO) mice were significantly higher than control mice when injected i.p. with an acetaminophen dose not lethal to the control. LKO livers exhibited higher basal expression of cytochrome P450 family 2 subfamily E member 1 (CYP2E1) and cytochrome P450 family 1 subfamily A member 2 (CYP1A2) that convert acetaminophen to highly reactive N-acetyl-p-benzoquinone imine. Upregulation of Cyp1a2 primary transcript and mRNA in LKO mice correlated with the elevation of aryl hydrocarbon receptor (AHR) and mediator 1 (MED1), two transactivators of Cyp1a2. Analysis of ChIP-seq data in the ENCODE (Encyclopedia of DNA Element) database identified association of CCCTC-binding factor (CTCF) with Ahr promoter in mouse livers. Both MED1 and CTCF are validated conserved miR-122 targets. Furthermore, depletion of Ahr, Med1, or Ctcf in Mir122-/- hepatocytes reduced Cyp1a2 expression. Pulse-chase studies found that CYP2E1 protein level is upregulated in LKO hepatocytes. Notably, miR-122 depletion sensitized differentiated human HepaRG cells to acetaminophen toxicity that correlated with upregulation of AHR, MED1, and CYP1A2 expression. Collectively, these results reveal a critical role of miR-122 in acetaminophen detoxification and implicate its therapeutic potential in patients with ALF.


Assuntos
Acetaminofen/toxicidade , Analgésicos não Entorpecentes/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , MicroRNAs/metabolismo , Acetaminofen/metabolismo , Analgésicos não Entorpecentes/metabolismo , Animais , Citocromo P-450 CYP1A2/biossíntese , Citocromo P-450 CYP2E1/biossíntese , Feminino , Regulação da Expressão Gênica/fisiologia , Hepatócitos/metabolismo , Humanos , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/metabolismo , Masculino , Camundongos , Camundongos Knockout
20.
Mol Cell ; 67(3): 400-410.e7, 2017 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-28735896

RESUMO

MicroRNA-122, an abundant and conserved liver-specific miRNA, regulates hepatic metabolism and functions as a tumor suppressor, yet systematic and direct biochemical elucidation of the miR-122 target network remains incomplete. To this end, we performed Argonaute crosslinking immunoprecipitation (Argonaute [Ago]-CLIP) sequencing in miR-122 knockout and control mouse livers, as well as in matched human hepatocellular carcinoma (HCC) and benign liver tissue to identify miRNA target sites transcriptome-wide in two species. We observed a majority of miR-122 binding on 3' UTRs and coding exons followed by extensive binding to other genic and non-genic sites. Motif analysis of miR-122-dependent binding revealed a G-bulged motif in addition to canonical motifs. A large number of miR-122 targets were found to be species specific. Upregulation of several common mouse and human targets, most notably BCL9, predicted survival in HCC patients. These results broadly define the molecular consequences of miR-122 downregulation in hepatocellular carcinoma.


Assuntos
Proteínas Argonauta/genética , Carcinoma Hepatocelular/genética , Imunoprecipitação/métodos , Neoplasias Hepáticas/genética , MicroRNAs/genética , Transcriptoma , Regiões 3' não Traduzidas , Animais , Proteínas Argonauta/metabolismo , Sítios de Ligação , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Estudos de Casos e Controles , Linhagem Celular Tumoral , Proliferação de Células , Biologia Computacional , Bases de Dados Genéticas , Regulação para Baixo , Éxons , Regulação Neoplásica da Expressão Gênica , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Knockout , MicroRNAs/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fenótipo , Interferência de RNA , Especificidade da Espécie , Fatores de Tempo , Fatores de Transcrição , Transcrição Genética , Transfecção , Via de Sinalização Wnt
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