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1.
Hepatology ; 67(1): 188-203, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28802060

RESUMO

Cancer cells display altered glucose metabolism characterized by a preference for aerobic glycolysis. The aerobic glycolytic phenotype of hepatocellular carcinoma (HCC) is often correlated with tumor progression and poorer clinical outcomes. However, the issue of whether glycolytic metabolism influences metastasis in HCC remains unclear. In the current study, we showed that knockdown of taurine up-regulated gene 1 (TUG1) induces marked inhibition of cell migration, invasion, and glycolysis through suppression of microRNA (miR)-455-3p. MiR-455-3p, which is transcriptionally repressed by p21, directly targets the 3' untranslated region of adenosine monophosphate-activated protein kinase subunit beta 2 (AMPKß2). The TUG1/miR-455-3p/AMPKß2 axis regulates cell growth, metastasis, and glycolysis through regulation of hexokinase 2 (HK2). TUG1 is clearly associated with HK2 overexpression and unfavorable prognosis in HCC patients. CONCLUSION: Our data collectively highlight that novel regulatory associations among TUG1, miR-455-3p, AMPKß2, and HK2 are an important determinant of glycolytic metabolism and metastasis in HCC cells and support the potential utility of targeting TUG1/HK2 as a therapeutic strategy for HCC. (Hepatology 2018;67:188-203).


Assuntos
Carcinoma Hepatocelular/genética , Regulação Neoplásica da Expressão Gênica/genética , Glicólise/genética , Neoplasias Hepáticas/genética , RNA Longo não Codificante/genética , Biópsia por Agulha , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Masculino , MicroRNAs/genética , Metástase Neoplásica/genética , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade , Transdução de Sinais/efeitos dos fármacos , Taurina/farmacologia , Regulação para Cima
2.
BMC Cancer ; 19(1): 176, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30808421

RESUMO

BACKGROUND: Zoledronic acid (ZA), a nitrogen-containing bisphosphonate, inhibits osteoclastogenesis. Emerging evidence suggests that ZA has anti-tumor and anti-metastatic properties for breast cancer cells. In a mouse model of ZA-related osteonecrosis of the jaw, ZA administration was found to suppress regulatory T-cells (Tregs) function. Our previous reports also demonstrated ZA acted as an immune modulator to block Tregs. Manipulation of Tregs represents a new strategy for cancer treatment. However, the relationship among ZA, Tregs, and cancer cells remains unclear. In this study, we investigated the effects of ZA on the interaction of breast cancer cells and Tregs. METHODS: The anti-tumor effect of ZA on triple negative breast cancer cell lines were validated by XTT, wound healing and apoptosis analysis. A flow cytometry-based assay was used to analyze the immunosuppressive effect of Tregs treated with media conditioned by breast cancer cells, and a transwell assay was used to evaluate the chemotactic migration of Tregs. Differential gene expression profile on MDA-MB-231 treated with ZA (25 µM) was analyzed by. microarrays to describe the molecular basis of actions of ZA for possible direct anti-tumor effects. Enzyme-linked immunosorbent assays and quantitative real-time PCR were used to investigate the effect of ZA on the expression of cytokines/factors by breast cancer cells. RESULTS: ZA was found to inhibit the proliferation and migration of breast cancer cells. Media conditioned by the MDA-MB-231 cells promoted the expansion, chemotactic migration, and immunosuppressive activity of Tregs, and these effects were attenuated in a dose-dependent manner by ZA treatment, and the attenuation was due to reduced expression of selected breast cancer cell factors (CCL2, CCL5, and IDO). CONCLUSIONS: ZA can significantly affect the interaction between breast cancer cells and Tregs. Our findings indicate that ZA is a potential therapeutic agent that can be used to reduce cancer aggressiveness by abolishing the supportive role of Tregs.


Assuntos
Fatores Imunológicos/farmacologia , Linfócitos T Reguladores/imunologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Ácido Zoledrônico/farmacologia , Comunicação Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Quimiocina CCL2/metabolismo , Quimiocina CCL5/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Linfócitos T Reguladores/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/imunologia , Microambiente Tumoral
3.
BMC Immunol ; 17(1): 45, 2016 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-27887569

RESUMO

BACKGROUND: CD4+CD25+ regulatory T (Treg) cells suppress tumor immunity by inhibiting immune cells. Manipulation of Treg cells represents a new strategy for cancer treatment. Zoledronic acid (ZA), a nitrogen-containing bisphosphonate, inhibits the expression of receptor activator of nuclear factor kappa-B ligand (RANKL) on osteoblasts to inhibit osteoclastogenesis. In a mouse model of bisphosphonate-related osteonecrosis of the jaw, administration of ZA suppressed Treg-cell activity and activated inflammatory Th17 cells. However, the interaction between ZA and Treg cells remained unclear. This study investigated the immune modulation of Treg cells by ZA. METHODS: Flow cytometry was used to analyze the phenotypic and immunosuppressive characteristics of Treg cells treated with ZA. Chemotactic migration was evaluated using transwell assays. Quantitative real-time PCR (qRT-PCR) was used to investigate the effect of ZA on the expression of suppressive molecules by Treg cells. RESULTS: Proliferation of isolated Treg cells in culture was inhibited by ZA, although ZA did not induce apoptosis. qRT-PCR and flow cytometry showed that ZA significantly downregulated the expression of CCR4, CTLA4, PD-1 and RANKL on Treg cells. Chemotactic migration and immunosuppressive functions were also significantly attenuated in Treg cells pretreated with ZA, and these effects were dose-dependent. Co-culture with Treg cells significantly increased the migration rate of breast cancer cells, while pretreatment of Treg cells with ZA attenuated this effect. CONCLUSIONS: Our findings demonstrated that ZA acted as an immune modulator by significantly inhibiting the expansion, migration, immunosuppressive function and pro-metastatic ability of Treg cells. Immunomodulation of Treg cells by ZA represents a new strategy for cancer therapy.


Assuntos
Neoplasias da Mama/imunologia , Vacinas Anticâncer/imunologia , Difosfonatos/farmacologia , Imidazóis/farmacologia , Fatores Imunológicos/farmacologia , Imunoterapia/métodos , Osteogênese , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Neoplasias da Mama/tratamento farmacológico , Antígenos CD4/metabolismo , Movimento Celular , Células Cultivadas , Técnicas de Cocultura , Difosfonatos/uso terapêutico , Feminino , Humanos , Imidazóis/uso terapêutico , Fatores Imunológicos/uso terapêutico , Imunoterapia/tendências , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Ativação Linfocitária , NF-kappa B/metabolismo , Ligante RANK/metabolismo , Transdução de Sinais , Linfócitos T Reguladores/efeitos dos fármacos , Ácido Zoledrônico
4.
Int J Cancer ; 137(1): 37-49, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25430639

RESUMO

The thyroid hormone, 3,3',5-triiodo-l-thyronine (T3 ), mediates several physiological processes, including embryonic development, cellular differentiation, metabolism and regulation of cell proliferation. Thyroid hormone (T3 ) and its receptor (TR) are involved in metabolism and growth. In addition to their developmental and metabolic functions, TRs play a tumor suppressor role, and therefore, their aberrant expression can lead to tumor transformation. Aberrant epigenetic silencing of tumor suppressor genes promotes cancer progression. The epigenetic regulator, Ubiquitin-like with PHD and ring finger domains 1 (UHRF1), is overexpressed in various cancers. In our study, we demonstrated that T3 negatively regulates UHRF1 expression, both in vitro and in vivo. Our results further indicate that UHRF1 regulation by T3 is indirect and mediated by Sp1. Sp1-binding elements of UHRF1 were identified at positions -664/-505 of the promoter region using the luciferase and chromatin immunoprecipitation assays. Notably, UHRF1 and Sp1 levels were elevated in subgroups of hepatocellular carcinoma patients and inversely correlated with TRα1 expression. Knockdown of UHRF1 expression should therefore provide a means to inhibit hepatoma cell proliferation. Expression of UHRF1 was downregulated by TRs, in turn, relieving silencing of the UHRF1 target gene, p21. Based on the collective findings, we propose that T3 /TR signaling induces hepatoma cell growth inhibition via UHRF1 repression.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Proliferação de Células/efeitos dos fármacos , Neoplasias Hepáticas/patologia , Receptores dos Hormônios Tireóideos/metabolismo , Tri-Iodotironina/farmacologia , Animais , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Regiões Promotoras Genéticas/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Fator de Transcrição Sp1/metabolismo , Ubiquitina-Proteína Ligases
5.
J Hepatol ; 62(6): 1328-40, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25617495

RESUMO

BACKGROUND & AIMS: Thyroid hormone (T3) and its receptor (TR) are involved in cell growth and cancer progression. Although deregulation of microRNA (miRNA) expression has been detected in many tumor types, the mechanisms underlying functional impairment and specific involvement of miRNAs in tumor metastasis remain unclear. In the current study, we aimed to elucidate the involvement of deregulated miRNA-130b (miR-130b) and its target genes mediated by T3/TR in cancer progression. METHODS: Quantitative reverse transcription-PCR, luciferase and chromatin immunoprecipitation assays were performed to identify the miR-130b transcript and the mechanisms implicated in its regulation. The effects of miR-130b on hepatocellular carcinoma (HCC) invasion were further examined in vitro and in vivo. Clinical correlations among miR-130b, TRs and interferon regulatory factor 1 (IRF1) were examined in HCC samples using Spearman correlation analysis. RESULTS: Our experiments disclosed negative regulation of miR-130b expression by T3/TR. Overexpression of miR-130b led to marked inhibition of cell migration and invasion, which was mediated via suppression of IRF1. Cell migration ability was promoted by T3, but partially suppressed upon miR-130b overexpression. Furthermore, miR-130b suppressed expression of epithelial-mesenchymal transition (EMT)-related genes, matrix metalloproteinase-9, phosphorylated mammalian target of rapamycin (mTOR), p-ERK1/2, p-AKT and p-signal transducer and activator of transcription (STAT)-3. Notably, miR-130b was downregulated in hepatoma samples and its expression patterns were inversely correlated with those of TRα1 and IRF1. CONCLUSIONS: Our data collectively highlight a novel pathway interlinking T3/TR, miR-130b, IRF1, the EMT-related genes, p-mTOR, p-STAT3 and the p-AKT cascade, which regulates the motility and invasion of hepatoma cells.


Assuntos
Movimento Celular/genética , Movimento Celular/fisiologia , MicroRNAs/genética , MicroRNAs/metabolismo , Tri-Iodotironina/metabolismo , Idoso , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Progressão da Doença , Regulação para Baixo , Transição Epitelial-Mesenquimal , Feminino , Células Hep G2 , Humanos , Fator Regulador 1 de Interferon/genética , Fator Regulador 1 de Interferon/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Invasividade Neoplásica/fisiopatologia , Receptores dos Hormônios Tireóideos/metabolismo , Transdução de Sinais
6.
J Nutr Biochem ; 121: 109438, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37666476

RESUMO

Combination therapies to induce mixed-type cell death and synthetic lethality have the potential to overcome drug resistance in cancer. In this study, we demonstrated that the curcumin-enhanced cytotoxicity of cisplatin/carboplatin in combination with gemcitabine was associated with Aurora A suppression-mediated G2/M arrest, and thus apoptosis, as well as MEK/ERK-mediated autophagy in human bladder cancer cells. Animal study data confirmed that curcumin combined with cisplatin/gemcitabine reduced tumorigenesis of xenograft in mice and this phenomenon was associated with elevated expressions of p-ERK and reduced p-Aurora A in tumors. Gene analyses using data repositories further revealed that reduced Aurora A expression alone did not significantly elevate the sensitivity of human bladder carcinoma cells to these anticancer drugs. Unlike other major cancer types, human bladder urothelial carcinoma tissue coexpressed higher AURKA and lower MAP1LC3B than normal tissue, and reduced Aurora A and induction of autophagy have been clinically associated with a better prognosis in patients with early but not advanced stage bladder cancer. Therefore, our results suggest that treatment strategies can utilize the synthetic lethal pair to concurrently suppress oncogenic Aurora A and induce autophagy by coadministrating curcumin with anticancer drugs for early-stage bladder cancer with high expression of Aurora A.

7.
Oncogene ; 41(2): 159-172, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34716430

RESUMO

Pseudogenes are generally considered "junk" DNA or "genomic fossils" generated during the evolution process that lack biological activity. However, accumulating reports indicate that pseudogenes have biological functions critical for cancer development. Experiments from the current study showed marked overexpression of the cytidine monophospho-N-acetylneuraminic acid hydroxylase pseudogene (CMAHP) in gastric cancer, which was associated with poor overall survival. However, the mechanisms underlying the activity of CMAHP in tumor development are largely unknown. Gene Set Enrichment Analysis (GSEA) revealed that CMAHP-correlated genes are significantly involved in epithelial-mesenchymal transition (EMT) and angiogenesis. Functional studies further confirmed that CMAHP mediates metastasis and angiogenesis in vitro and in vivo. Furthermore, CMAHP promoted cancer cell migration, invasion, and metastasis through Snail overexpression, which decreased ubiquitination mediated by NF-κB signaling. Angiogenesis is known to be induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation. CMAHP increased GM-CSF transactivation via promoting direct binding of c-Jun to the -1981/-1975 region of the GM-CSF promoter. Notably, CMAHP interacts with Histone H1.4 promoting histone acetylation to enhance c-Jun and RelA (p65) expression. Our collective findings provide novel evidence that CMAHP contributes to tumor progression and modulates metastasis and angiogenesis in gastric cancer.


Assuntos
Indutores da Angiogênese/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Neoplasias Gástricas/genética , Ubiquitinação/efeitos dos fármacos , Indutores da Angiogênese/farmacologia , Linhagem Celular Tumoral , Humanos , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Análise de Sobrevida
8.
Theranostics ; 9(8): 2361-2379, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31149049

RESUMO

Background & Aims: Hepatocellular carcinoma (HCC) is among the leading causes of cancer deaths worldwide. Many studies indicate that disruption of cellular thyroid hormone signaling promotes HCC progression. However, the mechanisms underlying the regulation of genes downstream of thyroid hormone actions in HCC have remained elusive. In the current study, we identified NUPR1 (nuclear protein-1), a stress-induced protein that overexpresses in various neoplasia, is upregulated by triiodothyronine/thyroid hormone receptor (T3/TR) signaling and aimed to elucidate its role in angiogenesis in cancer progression. Methods: Quantitative reverse transcription-PCR, luciferase promoter and chromatin immunoprecipitation assays were performed to identify the NUPR1 regulatory mechanism by T3/TR. In vitro and In vivo vascular formations were performed to detect the angiogenic function of NUPR1. Human angiogenesis arrays were performed to identify the downstream angiogenic pathway. The sorafenib resistant ability of TR/NUPR1 was further examined in vitro and in vivo. Clinical relevance of TR, NUPR1 and platelet-derived growth factor A (PDGFA) were investigate in HCC samples using qRT-PCR and western blot. Results: Our experiments disclosed positive regulation of NUPR1 expression by T3/TR through direct binding to the -2066 to -1910 region of the NUPR1 promoter. Elevated NUPR1 and TR expression link to poor survival in clinical HCC specimens. An analysis of clinicopathological parameters showed that expression of NUPR1 is associated with vascular invasion and pathology stage. Functional studies revealed that NUPR1 induced endothelial cell angiogenesis in vitro and in vivo. Using a human angiogenesis array, we identified PDGFA as a target of NUPR1 in the downstream angiogenic pathway. NUPR1 induced transcription of PDGFA through direct binding to the corresponding promoter region, and inhibition of the PDGFA signaling pathway impaired angiogenesis in human umbilical vein endothelial cells (HUVECs). Notably, the angiogenic effects of NUPR1/PDGFA were mediated by the MEK/ERK signaling pathway. TR/NUPR1 expression increased cell viability and resistance to sorafenib treatment. Moreover NUPR1 expression was positively correlated with TRα, TRß, and PDGFA expression. Conclusions: We propose that the T3/TR/NUPR1/PDGFA/MEK/ERK axis has a vital role in hepatocarcinogenesis and suggest NUPR1 as a potential therapeutic target in HCC.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Carcinoma Hepatocelular/fisiopatologia , Neoplasias Hepáticas/fisiopatologia , Proteínas de Neoplasias/biossíntese , Neovascularização Patológica , Fator de Crescimento Derivado de Plaquetas/metabolismo , Tri-Iodotironina/metabolismo , Animais , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Imunoprecipitação , Camundongos Endogâmicos BALB C , Reação em Cadeia da Polimerase em Tempo Real , Receptores dos Hormônios Tireóideos/metabolismo , Transdução de Sinais
9.
Neoplasia ; 20(1): 57-68, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29195126

RESUMO

Thyroid hormone, 3,3',5-triiodo-l-thyronine (T3), mediates several physiological processes, including embryonic development, cellular differentiation and cell proliferation, via binding to its nuclear thyroid receptors (TR). Previous microarray and Chromatin immunoprecipitation (ChIP)-on-ChIP analyses have revealed that interferon-stimulated gene 20 kDa (ISG20), an exoribonuclease involved in the antiviral function of interferon, is up-regulated by T3 in HepG2-TR cells. However, the underlying mechanisms of ISG20 action in tumor progression remain unknown to date. Here, we verified induction of ISG20 mRNA and protein expression by T3 in HepG2-TR cells. Based on the ChIP-on-ChIP database, potential thyroid hormone responsive element of the ISG20 promoter region was predicted, and the result confirmed with the ChIP assay. Functional assays showed that forced expression of ISG20 leads to significant promotion of metastasis and angiogenesis, both in vitro and in vivo. Furthermore, the angiogenic-related protein, interleukin-8 (IL-8), was up-regulated through a T3-mediated increase in ISG20, as determined using a human angiogenesis array kit. Induction of IL-8 signaling activated the p-JAK2/p-STAT3 pathway, in turn, leading to promotion of tumor metastasis and angiogenesis. Furthermore, ISG20 overexpression in hepatocellular carcinoma (HCC) specimens was positively correlated with clinical parameters, including vascular invasion, α-fetoprotein and tumor size. Higher ISG20 expression was significantly correlated with poorer recurrence-free survival in HCC patients. Our results collectively indicate higher TR-dependent expression of ISG20 in a subset of HCC, supporting an oncogenic role in HCC progression.


Assuntos
Exonucleases/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Hormônios Tireóideos/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Exonucleases/metabolismo , Exorribonucleases , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Transdução de Sinais
10.
Endocr Relat Cancer ; 25(12): 967-979, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30400024

RESUMO

Thyroid hormone (T3) and its receptor (TR) are involved in cancer progression. While deregulation of long non-coding RNA (lncRNA) expression has been detected in many tumor types, the mechanisms underlying specific involvement of lncRNAs in tumorigenicity remain unclear. Experiments from the current study revealed negative regulation of BC200 expression by T3/TR. BC200 was highly expressed in hepatocellular carcinoma (HCC) and effective as an independent prognostic marker. BC200 promoted cell growth and tumor sphere formation, which was mediated via regulation of cell cycle-related genes and stemness markers. Moreover, BC200 protected cyclin E2 mRNA from degradation. Cell growth ability was repressed by T3, but partially enhanced upon BC200 overexpression. Mechanistically, BC200 directly interacted with cyclin E2 and promoted CDK2-cyclin E2 complex formation. Upregulation of cell cycle-related genes in hepatoma samples was positively correlated with BC200 expression. Our collective findings support the utility of a potential therapeutic strategy involving targeting of BC200 for the treatment of HCC.


Assuntos
Carcinogênese/metabolismo , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , RNA Longo não Codificante/metabolismo , Hormônios Tireóideos/metabolismo , Idoso , Animais , Linhagem Celular Tumoral , Quinase 2 Dependente de Ciclina/metabolismo , Ciclinas/metabolismo , Feminino , Humanos , Masculino , Camundongos Nus , Pessoa de Meia-Idade , Receptores dos Hormônios Tireóideos/metabolismo
11.
Protein Sci ; 14(9): 2228-35, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16081647

RESUMO

Transmissible spongiform encephalopathies (TSEs) are believed to be caused by an unconventional infectious agent, the prion protein. The pathogenic and infectious form of prion protein, PrPSc, is able to aggregate and form amyloid fibrils, very stable and resistant to most disinfecting processes and common proteases. Under specific conditions, PrPSc in bovine spongiform encephalopathy (BSE) brain tissue was found degradable by a bacterial keratinase and some other proteases. Since this disease-causing prion is infectious and dangerous to work with, a model or surrogate protein that is safe is needed for the in vitro degradation study. Here a nonpathogenic yeast prion-like protein, Sup35NM, cloned and overexpressed in E. coli, was purified and characterized for this purpose. Aggregation and deaggregation of Sup35NM were examined by electron microscopy, gel electrophoresis, Congo red binding, fluorescence, and Western blotting. The degradation of Sup35NM aggregates by keratinase and proteinase K under various conditions was studied and compared. These results will be of value in understanding the mechanism and optimization of the degradation process.


Assuntos
Endopeptidase K/metabolismo , Peptídeo Hidrolases/metabolismo , Príons/química , Príons/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Western Blotting , Vermelho Congo/metabolismo , Escherichia coli/genética , Fluorescência , Microscopia Eletrônica/métodos , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/metabolismo , Fatores de Terminação de Peptídeos , Príons/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Temperatura , Fatores de Tempo
12.
Oncotarget ; 6(17): 15050-64, 2015 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-25940797

RESUMO

The thyroid hormone, 3,3',5-triiodo-L-thyronine (T3), regulates cell growth, development and differentiation via interactions with thyroid hormone receptors (TR), but the mechanisms underlying T3-mediated modulation of cancer progression are currently unclear. Lipocalin 2 (LCN2), a tumor-associated protein, is overexpressed in a variety of cancer types. Oligonucleotide microarray, coupled with proteomic analysis, has revealed that LCN2 is positively regulated by T3/TR. However, the physiological role and pathway of T3-mediated regulation of LCN2 in hepatocellular carcinogenesis remain to be characterized. Upregulation of LCN2 after T3 stimulation was observed in a time- and dose-dependent manner. Additionally, TRE on the LCN2 promoter was identified at positions -1444/-1427. Overexpression of LCN2 enhanced tumor cell migration and invasion, and conversely, its knockdown suppressed migration and invasion, both in vitro and in vivo. LCN2-induced migration occurred through activation of the Met/FAK cascade. LCN2 was overexpressed in clinical hepatocellular carcinoma (HCC) patients, compared with normal subjects, and positively correlated with TRα levels. Both TRα and LCN2 showed similar expression patterns in relation to survival rate, tumor grade, tumor stage and vascular invasion. Our findings collectively support a potential role of T3/TR in cancer progression through regulation of LCN2 via the Met/FAK cascade. LCN2 may thus be effectively utilized as a novel marker and therapeutic target in HCC.


Assuntos
Proteínas de Fase Aguda/genética , Quinase 1 de Adesão Focal/genética , Lipocalinas/genética , Neoplasias Hepáticas/genética , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais/genética , Hormônios Tireóideos/metabolismo , Proteínas de Fase Aguda/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Movimento Celular/genética , Quinase 1 de Adesão Focal/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Lipocalina-2 , Lipocalinas/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Camundongos SCID , Invasividade Neoplásica , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo , Elementos de Resposta/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Hormônios Tireóideos/farmacologia , Transplante Heterólogo , Tri-Iodotironina/metabolismo , Tri-Iodotironina/farmacologia
13.
Oncotarget ; 6(11): 9341-54, 2015 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-25823820

RESUMO

Despite numerous investigations on metastasis, the determinants of metastatic processes remain unclear. We aimed to identify the metastasis-associated genes in hepatocellular carcinoma (HCC). Potent metastatic SK-hep-1 (SK) cells, designated 'SKM', were generated using Transwell assay followed by selection in a mouse model. Genes expressed differentially in SKM and SK cells were identified via microarray analyses. A small form of Neural precursor cell-expressed developmentally downregulated 4 (sNEDD4) was identified to be overexpressed in SKM cells, which was confirmed as a novel transcript using liquid chromatography-mass spectrometry. In clinical specimens, sNEDD4 was significantly overexpressed in tumors and serves as a poor prognostic factor for male patients with HCC (P = 0.035). Upon subcutaneous introduction of sNEDD4-overexpressing SK cells into flanks of nude mice, tumors grew faster than those of the control group. Furthermore, sNEDD4-mediated promotion of tumor metastasis was demonstrated in the orthotopic mouse model. Overexpression of sNEDD4 increased the invasive ability of SK cells through upregulation of matrix metalloproteinase 9 and inhibited serum deprivation-induced apoptosis via upregulation of myeloid cell leukemia 1. In conclusion, sNEDD4 is a novel metastasis-associated gene, which prevents apoptosis under nutrient restriction conditions. The present findings clearly support the prognostic potential of sNEDD4 for HCC.


Assuntos
Apoptose/genética , Carcinoma Hepatocelular/patologia , Complexos Endossomais de Distribuição Requeridos para Transporte/fisiologia , Neoplasias Hepáticas/patologia , Ubiquitina-Proteína Ligases/fisiologia , Animais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidade , Linhagem Celular Tumoral , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Camundongos SCID , Ubiquitina-Proteína Ligases Nedd4 , Invasividade Neoplásica , Prognóstico , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiologia , Ubiquitina-Proteína Ligases/genética , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Protein Sci ; 11(3): 659-68, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11847288

RESUMO

The two amino acid residues, Asp 99 and Asp 201, involved in the coordination of the two calcium atoms in the X-ray structure of bovine pancreatic (bp) DNase, were individually changed by site-directed mutagenesis. The two altered proteins, brDNase(D99A) and brDNase(D201A) were expressed in Escherichia coli and purified by anion exchange chromatography. Equilibrium dialysis showed that mutation destroyed one Ca(2+)-binding site each in brDNase(D99A) and brDNase(D201A). Compared with bpDNase, the Vmax value for brDNase(D99A) remained unchanged and that for brDNase(D201A) was decreased, whereas the K(m) values for the two variants were increased two- to threefold when the DNA hydrolytic hyperchromicity assay was used. Like bpDNase, brDNase(D99A) was able to make double scission on duplex DNA with Mg(2+) plus Ca(2+) and was effectively protected by Ca(2+) from the trypsin inactivation. But under the same conditions, brDNase(D201A) lost the double-scission ability and was not protected by Ca(2+). Nevertheless, the two variant proteins retained the characteristics of the Ca(2+)-induced conformational changes and the Ca(2+) protection against the beta-mercaptoethanol disruption of the essential disulfide bond, suggesting that other weaker Ca(2+)-binding sites not found in the X-ray structure were responsible for these properties. Therefore, the two structural calcium atoms are not for maintaining the overall conformation of the active DNase, as it has been indicated in the X-ray analysis, but rather play the role in the fine-tuning of the DNase activity.


Assuntos
Cálcio/química , Desoxirribonuclease I/química , Pâncreas/enzimologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Cálcio/metabolismo , Bovinos , Desoxirribonuclease I/genética , Desoxirribonuclease I/metabolismo , Desoxirribonucleases/metabolismo , Escherichia coli , Humanos , Cinética , Metais/farmacologia , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Pâncreas/química , Plasmídeos/metabolismo , Ligação Proteica , Proteínas Recombinantes/química , Termodinâmica , Tripsina/metabolismo
15.
Protein Sci ; 13(4): 875-83, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15044724

RESUMO

We characterized the biochemical functions of the small nonessential (C101-C104) and the large essential (C173-C209) disulfides in bovine pancreatic (bp) DNase using alanine mutants [brDNase(C101A)] and [brDNase(C173A) and brDNase(C209A)], respectively. We also characterized the effects of an additional third disulfide [brDNase(F192C/A217C)]. Without the Ca(2+) protection, bpDNase and brDNase(C101A) were readily inactivated by trypsin, whereas brDNase(F192C/A217C) remained active. With Ca(2+), all forms of DNase, except for brDNase(C101A), were protected against trypsin. All forms of DNase, after being dissolved in 6 M guanidine-HCl, were fully reactivated by diluting into a Ca(2+)-containing buffer. However, when diluted into a Ca(2+)-free buffer, bpDNase and brDNase(C101A) remained inactive, but 60% of the bpDNase activity was restored with brDNase(F192C/A217C). When heated, bpDNase was inactivated at a transition temperature of 65 degrees C, brDNase(C101A) at 60 degrees C, and brDNase(F192C/A217C) at 73 degrees C, indicating that the small disulfide, albeit not essential for activity, is important for the structural integrity, and that the introduction of a third disulfide can further stabilize the enzyme. When pellets of brDNase(C173A) and brDNase(C209A) in inclusion bodies were dissolved in 6 M guanidine-HCl and then diluted into a Ca(2+)-containing buffer, 10%-18% of the bpDNase activity was restored, suggesting that the "essential" disulfide is not absolutely crucial for enzymatic catalysis. Owing to the structure-based sequence alignment revealing homology between the "nonessential" disulfide of bpDNase and the active-site motif of thioredoxin, we measured 39% of the thioredoxin-like activity for bpDNase based on the rate of insulin precipitation (DeltaA650nm/min). Thus, the disulfides in bpDNase not only play the role of stabilizing the protein molecule but also may engage in biological functions such as the disulfide/dithiol exchange reaction.


Assuntos
Desoxirribonuclease I/química , Desoxirribonuclease I/genética , Dissulfetos/química , Substituição de Aminoácidos/genética , Animais , Sítios de Ligação , Cálcio/química , Bovinos , Guanidina/química , Insulina/química , Desnaturação Proteica , Homologia Estrutural de Proteína , Tiorredoxinas/química , Tripsina/química
16.
Cancer Lett ; 351(2): 222-31, 2014 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-24933454

RESUMO

MicroRNAs (miRNAs) play an important role to contribute carcinogenesis. The aim of the current study was to identify useful biomarkers from miRNAs. Differential miRNA profiles were analyzed using the miRNA qRT-PCR-based assay. Two of the most upregulated miRNAs were selected and validated. The miR-196a/-196b levels were significantly increased in gastric cancer (GC) tissues (n=109). Overexpression of miR-196a/-196b was significantly associated with tumor progression and poorer 5-year survival outcomes. Overexpression of miR-196a/-196b enhances GC cell migration and invasion. Further, radixin was identified as a target gene of miR-196a/-196b. Elevated miR-196a/-196b expression in GC cells led to reduced radixin protein levels and vice versa. Notably, an inverse correlation between miR-196a/-196b and radixin mRNA and protein expression was observed in GC tissues with in situ hybridization and immunohistochemistry analyses. Together, miR-196a/-196b inhibitory oligonucleotides or overexpression of the radixin may thus have therapeutic potential in suppressing GC metastasis.


Assuntos
Proteínas do Citoesqueleto/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Idoso , Linhagem Celular Tumoral , Movimento Celular/genética , Proteínas do Citoesqueleto/biossíntese , Regulação para Baixo , Feminino , Genes Supressores de Tumor , Humanos , Imuno-Histoquímica , Masculino , Proteínas de Membrana/biossíntese , MicroRNAs/biossíntese , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Transfecção , Células Tumorais Cultivadas , Regulação para Cima
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