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1.
Br J Haematol ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32037523

RESUMO

The serine synthesis pathway (SSP) is active in multiple cancers. Previous study has shown that bortezomib (BTZ) resistance is associated with an increase in the SSP in multiple myeloma (MM) cells; however, the underlying mechanisms of SSP-induced BTZ resistance remain unclear. In this study, we found that phosphoglycerate dehydrogenase (PHGDH), the first rate-limiting enzyme in the SSP, was significantly elevated in CD138+ cells derived from patients with relapsed MM. Moreover, high PHGDH conferred inferior survival in MM. We also found that overexpression of PHDGH in MM cells led to increased cell growth, tumour formation, and resistance to BTZ in vitro and in vivo, while inhibition of PHGDH by short hairpin RNA or NCT-503, a specific inhibitor of PHGDH, inhibited cell growth and BTZ resistance in MM cells. Subsequent mechanistic studies demonstrated PHGDH decreased reactive oxygen species (ROS) through increasing reduced glutathione (GSH) synthesis, thereby promoting cell growth and BTZ resistance in MM cells. Furthermore, adding GSH to PHGDH silenced MM cells reversed S phase arrest and BTZ-induced cell death. These findings support a mechanism in which PHGDH promotes proliferation and BTZ resistance through increasing GSH synthesis in MM cells. Therefore, targeting PHGDH is a promising strategy for MM therapy.

2.
Mol Oncol ; 2020 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-31955515

RESUMO

NEK2 is associated with drug resistance in multiple cancers. Our previous studies indicated that high NEK2 confers inferior survival in multiple myeloma (MM); thus, a better understanding of the mechanisms by which NEK2 induces drug resistance in MM is required. In this study, we discovered that NEK2 enhances MM cell autophagy, and a combination of autophagy inhibitor chloroquine (CQ) and chemotherapeutic bortezomib (BTZ) significantly prevents NEK2-induced drug resistance in MM cells. Interestingly, NEK2 was found to bind and stabilize Beclin-1 protein but did not affect its mRNA expression and phosphorylation. Moreover, autophagy enhanced by NEK2 was significantly prevented by knockdown of Beclin-1 in MM cells, suggesting that Beclin-1 mediates NEK2-induced autophagy. Further studies demonstrated that Beclin-1 ubiquitination is decreased through NEK2 interaction with USP7. Importantly, knockdown of Beclin-1 sensitized NEK2-overexpressing MM cells to BTZ in vitro and in vivo. In conclusion, we identify a novel mechanism whereby autophagy is activated by the complex of NEK2/USP7/Beclin-1 in MM cells. Targeting the autophagy signaling pathway may provide a promising therapeutic strategy to overcome NEK2-induced drug resistance in MM.

3.
J Toxicol Environ Health A ; 82(21): 1113-1119, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31818208

RESUMO

Microcystin-LR (MC-LR), a cyclic heptapeptide toxin produced by cyanobacteria, was found to induce genotoxic actions in various types of cells. Some investigators reported that microcystin-LR acted as tumor initiator in the observed genotoxic action mediated by this cyanotoxin. However, the underlying mechanisms underlying MC-induced DNA damage in the human intestine epithelium cell line (NCM460) are not known. The purpose of this study was to examine the influence of 24 hr exposure to 5 or 10 µM MC-LR on intestinal DNA damage using NCM460 intestine cell line as a model. Data showed that MC-LR increased Olive tail moment (OTM) as evidenced by the comet assay, inhibited protein phosphatase 2A (PP2A) activity, elevated reactive oxygen species levels (ROS) and enhanced γ-H2AX and p-p53 protein expression levels. Results indicated that MC-LR produced intestinal DNA damage by inhibiting PP2A activity, activating p53 protein and subsequently initiating excess generation of ROS. These observations suggest that MC-LR-induced intestinal DNA damage involves a complex series of events that include oxidant stress, PP2A enzymic inhibition and activation of p53 protein.

4.
J Toxicol Environ Health A ; 82(21): 1129-1136, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31818223

RESUMO

Microcystin-LR (MC-LR) variant exposure poses a potential health hazard to ecosystem, animals, and humans. Previously investigators showed that autophagy plays a key role in MC-LR induced cytotoxicity immortalized murine ovarian granular KK-1 cells and rat Sertoli cells. Recently exposure to MC-LR via drinking water was reported to accumulate in mouse brain with associated adverse oxidant and inflammatory responses. However, autophagy the physiological mechanism required for cells to degrade their own impaired organelles to maintain their homeostasis has not been determined with respect to MC-LR actions on the central nervous system (CNS). Thus, the aim of this study was to examine the effects of MC-LR on autophagy using human neuroblastoma SK-N-SH cells as CNS model. Data demonstrated that after treatment with 15 or 30 µmol/L MC-LR for 48 hr significantly reduced survival rate was noted in SK-N-SH cells. MC-LR increased the expression levels of autophagy-related proteins light chain 3 (LC3) II/I and p62 in SK-N-SH cells, resulting in the accumulation of LC3 and increased intracellular free calcium ion levels. Data indicated that MC-LR induced adverse effects on the CNS as evidenced by decreased cellular survival associated with inhibition of autophagy flux and consequent enhanced autophagosomes accumulation.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31835602

RESUMO

Microcystin-LR (MC-LR) is a potent hepatotoxin, but a few studies suggested that it might also induce nephrotoxicity. However, nephrotoxicity induced by prolonged oral exposure to MC-LR is unknown. The aim of this study was to evaluate the potential influence of MC-LR on the kidney in mice following chronic exposure to MC-LR. In this study, we evaluated the nephrotoxicity of MC-LR in mice drinking water at different concentrations (1, 30, 60, 90, and 120 µg/L) for 6 months for the first time. The results showed that the kidney weights and the kidney indexes of mice were not altered in the MC-LR treated mice, compared with the control group. In addition, the renal function indicators revealed that the serum creatinine (SCr) levels were not significant changes after exposure to MC-LR. The blood urea nitrogen (BUN) levels were markedly decreased after exposure to 90 and 120µg/L MC-LR for 3 months. The BUN levels were lower than that of the control group after exposure to 120µg/L MC-LR for 6 months. The histopathological investigation revealed enlarged renal corpuscles, widened of kidney tubules, and lymphocyte infiltration in the interstitial tissue and the renal pelvis after exposure to 60, 90, and 120 µg/L MC-LR. Consequently, our results suggested that long-term exposure to MC-LR might be one important risk of kidney injury, which will provide important clues for the prevention of renal impairment.

6.
Toxins (Basel) ; 11(7)2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31336817

RESUMO

Microcystin-LR (MC-LR), a cyanotoxin produced by cyanobacteria, induces oxidative stress in various types of cells. Prodigiosin, a red linear tripyrrole pigment, has been recently reported to have antimicrobial, antioxidative, and anticancer properties. How prodigiosin reacts to reactive oxygen species (ROS) induced by MC-LR is still undetermined. This study aimed to examine the effect of prodigiosin against oxidative stress induced by MC-LR in HepG2 cells. Ros was generated after cells were treated with MC-LR and was significantly inhibited with treatment of prodigiosin. In prodigiosin-treated cells, the levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2-related phase II enzyme heme oxygenase-1 (HO-1) were increased. Besides, prodigiosin contributed to enhance nuclear Nrf2 level and repressed ubiquitination. Furthermore, prodigiosin promoted Nrf2 protein level and inhibited ROS in Nrf2 knocked down HepG2 cells. Results indicated that prodigiosin reduced ROS induced by MC-LR by enhancing Nrf2 translocation into the nucleus in HepG2 cells. The finding presents new clues for the potential clinical applications of prodigiosin for inhibiting MC-LR-induced oxidative injury in the future.

7.
Trans R Soc Trop Med Hyg ; 113(8): 477-482, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31111936

RESUMO

BACKGROUND: Perceived stigma is a common problem among people living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) (PLWHA). In recent years, the number of older adults with HIV/AIDS has rapidly increased in China. However, HIV/AIDS-related perceived stigma and associated factors in older PLWHA remain unknown. METHODS: A cross-sectional study was conducted in Yongzhou. Participants were recruited via the Hunan HIV/AIDS Registry system. All participants were ≥50 y of age at the time of their HIV diagnosis. Sowell's HIV Stigma Scale was used to measure perceived stigma. RESULTS: A total of 193 participants were interviewed, of which 132 (68.4%) were male. The ages of the participants ranged from 50 to 82 y and the average age was 61.1±5.95 y. Eighteen (9.3%) subjects were ethnic minorities. Older PLWHA reported a relatively high level of perceived stigma, especially individuals of Han ethnicity having high annual incomes. The individuals who had disclosed their HIV-positive status to all their family had higher scores on the dimension related to blame. Regression analysis showed that ethnicity, annual income, living arrangement and disclosure patterns were the main associated factors of perceived stigma. CONCLUSIONS: Perceived stigma is common in older Chinese PLWHA. Individuals of ethnic minorities or with higher economic status have higher levels of stigma. Family relationships have a deep influence on perceived stigma.

8.
Toxins (Basel) ; 11(3)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30875960

RESUMO

Microcystin-LR is a cyclic heptapeptide hepatotoxin produced by harmful cyanobacteria. A panel of microRNAs containing miR-451a were found to be significantly changed in normal human liver cells HL7702 after exposure to microcystin-LR (MC-LR) in our previous study. However, the functions of miR-451a in hepatotoxicity induced by MC-LR remained unclear. The study aimed to investigate the impacts of miR-451a in HL7702 cells following treatment with 5 or 10 µM MC-LR. The comet assay indicated that MC-LR can influence Olive tail moment (OTM) in HL7702 cells. Furthermore, increase of miR-451a significantly repressed DNA damage and the protein expression level of γ-H2AX induced by MC-LR. Moreover, over-expression of miR-451a inhibited the expression level of p-AKT1 protein in cells following treatment by MC-LR. These results showed that miR-451a may protect from MC-LR-induced DNA damage by down-regulating the expression of p-AKT1, which provides new clues for the diagnosis and therapy policies for liver damage induced by MC-LR.


Assuntos
Dano ao DNA , MicroRNAs , Microcistinas/toxicidade , Linhagem Celular , Humanos , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo
9.
Molecules ; 24(4)2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30781396

RESUMO

Fisetin, a dietary flavonoid, is reported to have cellular antioxidant activity with an unclear mechanism. In this study, we investigated the effect of fisetin on the nuclear factor, erythroid 2-like 2 (Nrf2) signaling pathway in HepG2 cells to explore the cellular antioxidant mechanism. Fisetin upregulated the mRNA expression of heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), glutamate-cysteine ligase modifier subunit (GCLM), and NAD(P)H quinone oxidoreductase-1 (NQO1), and induced the protein of HO-1 but had no significant effect on the protein of GCLC, GCLM and NQO1. Moreover, nuclear accumulation of Nrf2 was clearly observed by immunofluorescence analysis and western blotting after fisetin treatment, and an enhanced luciferase activity of antioxidant response element (ARE)-regulated transactivation was obtained by dual-luciferase reporter gene assays. In addition, fisetin upregulated the protein level of Nrf2 and downregulated the protein level of Kelch-like ECH-associated protein 1 (Keap1). However, fisetin had no significant effect on Nrf2 mRNA expression. When protein synthesis was inhibited with cycloheximide (CHX), fisetin prolonged the half-life of Nrf2 from 15 min to 45 min. When blocking Nrf2 degradation with proteasome inhibitor MG132, ubiquitinated proteins were enhanced, and fisetin reduced ubiquitination of Nrf2. Taken together, fisetin translocated Nrf2 into the nucleus and upregulated the expression of downstream HO-1 gene by inhibiting the degradation of Nrf2 at the post-transcriptional level. These data provide the molecular mechanism to understand the cellular antioxidant activity of fisetin.


Assuntos
Antioxidantes/farmacologia , Flavonoides/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Elementos de Resposta Antioxidante/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glutamato-Cisteína Ligase/metabolismo , Heme Oxigenase-1/metabolismo , Células Hep G2 , Humanos , NAD(P)H Desidrogenase (Quinona)/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos
10.
Environ Toxicol ; 34(4): 495-504, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30600586

RESUMO

Formaldehyde (FA) is a ubiquitous environmental pollutant, which can induce apoptosis in lung cell and is related to the pathogenesis of asthma, pneumonia, and chronic obstructive pulmonary disease. Heat shock protein 70 (Hsp70) is an ATP-dependent molecular chaperone and exhibits an anti-apoptosis ability in a variety of cells. Previous studies reported that the expression of Hsp70 was induced when organisms were exposed to FA. Whether Hsp70 plays a role in the FA-induced apoptosis and the involved cell signaling pathway remain largely unknown. In this study, human bronchial epithelial cells with overexpressed Hsp70 and the control were exposed to different concentrations of FA (0, 40, 80, and 160 µmol/L) for 24 hours. Apoptosis and the expression levels of PI3K, Akt, p-Akt, MEK, p-MEK, and GLI2 were detected by Annexin-APC/7AAD double-labeled flow cytometry and western blot. The results showed that overexpression of Hsp70 decreased the apoptosis induced by FA and alleviated the decline of PI3k and p-Akt significantly. Inhibitor (LY 294002, a specific inhibitor of PI3K-Akt) test result indicated that PI3K-Akt signaling pathway was involved in the inhibition of FA-induced apoptosis by Hsp70 overexpression and also active in the maintenance of GLI2 level. However, it also suggested that other signaling pathways activated by overexpressed Hsp70 participated in this process, which was needed to be elucidated in further research.


Assuntos
Apoptose/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Células Epiteliais/efeitos dos fármacos , Formaldeído/toxicidade , Proteínas de Choque Térmico HSP70/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Apoptose/genética , Relação Dose-Resposta a Droga , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Transdução de Sinais
11.
J Cell Biochem ; 120(3): 3547-3558, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30295336

RESUMO

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in southern China and Southeast Asia, but the molecular mechanism of its pathogenesis is poorly understood. Our previous work demonstrated that NEK2 is overexpressed in multiple cancers. However, how NEK2 involves in NPC development remains to be elucidated. In this study, we firstly identified NEK2, located at +1q32-q33, a late event in NPC pathogenesis, overexpressed in the stage III-IV and paired sequential recurrent patients with NPC by immunohistochemistry. Furthermore, Kaplan-Meier analysis indicated high NEK2 conferred an inferior overall survival in NPC. In addition, cisplatin experiments with cell counting kit-8, colony formation, and a xenograft mice model of NPC demonstrated that NEK2 contributed to proliferation and cisplatin resistance in vitro and in vivo. On the contrary, downregulation of NEK2 by short hairpin RNA inhibited NPC cell growth and increased the sensitivity of cisplatin treatment in vitro. Thus, increased expression of NEK2 protein could not be predicted for poor survival but used as a novel biomarker for recurrence of NPC. Targeting NEK2 has the potential to eradicate the cisplatin-based chemotherapy resistant NPC cells.

12.
J Toxicol Environ Health A ; 81(21): 1135-1141, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30422063

RESUMO

Several studies previously demonstrated that microcystin (MC)-LR produced cytoskeletal damage, especially to actin filaments. However, the underlying mechanisms of MC-induced cytoskeletal reorganization remain to be determined. The aim of this study was to examine the effects of 5 or 10 µM MC-LR on microfilament depolarization and expression of microRNA-451a (miR-451a) which plays a crucial role in cellular processes including cell proliferation, apoptosis and tumorigenesis in HL7702 liver cells after 24 hr treatment. Data demonstrated that MC-LR increased microfilament depolarization, elevated phosphorylation levels of mitogen-activated protein kinase (MAPK/ERK1/2) and vasodilator-stimulated phosphoprotein (VASP) but lowered miR-451a RNA expression levels. These molecular processes were associated with no marked changes in total protein ERK1/2. Data demonstrate that transfection with miR-451a may not be effective in the presence of MC-LR as evidenced by the inability of excess microRNA to prevent toxin-induced inhibition of threonine protein phosphatases1 (PP1) and 2A (PP2A) and microfilament reorganization in HL7702 cells.


Assuntos
Citoesqueleto de Actina/fisiologia , Toxinas Bacterianas/toxicidade , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Microcistinas/toxicidade , Citoesqueleto de Actina/efeitos dos fármacos , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosforilação
13.
J Toxicol Environ Health A ; 81(22): 1165-1172, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30430930

RESUMO

The occurrence of microcystin-LR(MC-LR) variant a known hepatotoxin constitutes a global public health concern. However, the molecular mechanisms underlying MC-LR-induced hepatotoxicity remain to be determined. The aim of this study was to investigate whether long noncoding RNAs (lncRNA) were involved in MC-LR-mediated hepatotoxicity using human normal liver cell line HL7702 to profile lncRNAs after 24 hr treatment with MC-LR. With the use of high-throughput sequencing techniques, data showed that the expression levels of 37, 33, 34, 35 lncRNA were significantly altered following exposure to 1, 2.5, 5, or 10 µM MC-LR, respectively. In particular, the expression levels of LINC00847, MIR22HG and LNC_00027 were markedly increased in all treatment groups. It is of interest that LNC_00027 was identified as a novel lncRNA. Quantitative real-time PCR (qPCR) was employed to determine the differentially expressed lncRNA levels. Analysis using Gene Ontology (GO) enrichment identified the functions of target genes involved in systems development, metabolism, and protein binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis demonstrated that MC-LR exposure upregulated some important signaling pathways including pathway in cancer, PI3K-AKT signaling and MAPK pathway. In summary, data indicate that the MC-LR-induced alterations in lncRNA may be associated with hepatotoxicity and that upregulation of LINC00847, MIR22HG and LNC_00027 may play important roles in the observed MC-mediated liver damage.


Assuntos
Toxinas Bacterianas/toxicidade , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Microcistinas/toxicidade , RNA Longo não Codificante/genética , Hepatócitos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fígado/metabolismo , RNA Longo não Codificante/metabolismo
14.
Int J Oncol ; 53(3): 1138-1148, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29956730

RESUMO

Resistance to radiotherapy and chemotherapy currently represents one of the major reasons for therapeutic failure in nasopharyngeal carcinoma (NPC). However, the mechanisms underlying resistance to chemotherapy in NPC remain unclear. In this study, cell counting assay, cell cycle assay and senescence associated ß-galactosidase activity were performed to evaluate cell growth, proliferation and senescence, respectively. We found that the aberrant expression of cyclooxygenase-2 (COX-2) was associated with a poor outcome and recurrance in patients with NPC. In NPC cells, COX-2 overexpression increased cell proliferation, inhibited cellular senescence and resulted in chemoresistance, while the knockdown of COX-2 reduced cell proliferation, promoted cellular senescence and overcame chemoresistance. Furthermore, fibroblasts from COX-2 knockout mice exhibited cellular senescence, particularly when treated with chemotherapeutic agents. Mechanistically, COX-2 interacted with p53 protein and inhibited cellular senescence, which resulted in chemotherapeutic resistance. On the whole, these findings indicate that COX-2 may play a critical role in chemotherapeutic resistance in NPC via the inhibition of chemotherapy-induced senescence via the inactivation of p53. This study provides experimental evidence for the preclinical value of increasing chemotherapy-induced senescence by targeting COX-2 as an effective antitumor treatment in patients with recurrent NPC.


Assuntos
Antineoplásicos/farmacologia , Carcinoma/tratamento farmacológico , Senescência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Neoplasias Nasofaríngeas/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Animais , Antineoplásicos/uso terapêutico , Benzotiazóis/farmacologia , Biomarcadores Tumorais , Carcinoma/mortalidade , Carcinoma/patologia , Linhagem Celular Tumoral , Proliferação de Células , Ciclo-Oxigenase 2/genética , Resistencia a Medicamentos Antineoplásicos , Feminino , Fibroblastos , Perfilação da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Recidiva Local de Neoplasia/epidemiologia , Cultura Primária de Células , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Organismos Livres de Patógenos Específicos , Análise de Sobrevida , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo
15.
J Toxicol Environ Health A ; 81(5): 89-97, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29265921

RESUMO

Microcystin-LR (MC-LR), the most common microcystin (MC) present in water is known to pose a significant threat to human health especially hepatotoxicity. However, the specific molecular mechanisms underlying MC-LR-induced hepatic cellular damage still remain to be determined. MicroRNAs (miRNAs) are known to play key roles in cellular processes including development, cell proliferation and responsiveness to stress. Thus, this study aimed to examine, whether miRNAs were involved in the observed MC-LR-mediated liver damage using miRNA profiling of a human normal liver cell line HL7702 using high-throughput sequencing techniques. Protein phosphatase 2A (PP2A) activity, an established biomarker of microcystin toxicity, was determined 24 hr following treatment with the algal toxin to confirm responsiveness. Data demonstrated that MC-LR significantly inhibited PP2A activity in a concentration-dependent manner with inhibitory concentration (IC50) value of 4.6 µM. Compared with control cells, treatment with MC-LR at concentrations of 1, 2.5, 5 or 10 µM significantly modified expression of levels of 3, 10, 9, and 99 miRNAs, respectively. Expression levels of miR-15b-3p were significantly increased in all 4 treatment groups, while miR-4521 expression levels were markedly reduced. In the case of miR-451a, 1, 5 or 10 µM also significantly lowered expression levels. However, a significant rise in miR-451a was noted in cells exposed to 2.5 µM toxin. The results obtained from miRNA differential expression levels were confirmed by real-time fluorescent quantitative PCR (qPCR). Gene Ontology (GO) enrichment analysis of hepatic cells demonstrated that miRNAs significantly altered were involved in systems development, metabolism, and protein binding. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis data showed that target genes of differentially expressed miRNAs in liver cells predominantly participated in mechanistic target of rapamycin kinase (mTOR), Ras, Ras-related protein 1 (Rap1), hypoxia inducible factor 1 (HIF-1), and cancer development. In summary, evidence indicates that MC-LR-induced hepatotoxicity may be associated with alterations in miRNAs. Evidence indicates that alterations in miR-451a, miR-4521 and miR-15b-3p may be involved in the observed MC-LR- induced hepatotoxicity.


Assuntos
Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , MicroRNAs/genética , Microcistinas/toxicidade , Linhagem Celular , Perfilação da Expressão Gênica , Hepatócitos/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Fígado/patologia , MicroRNAs/metabolismo
16.
Pharmacogenomics ; 18(18): 1659-1670, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29173032

RESUMO

AIM: To evaluate the potential association of the genetic polymorphisms in ABCB1, ARRB2, DRD1 and OPRD1 genes with methadone dosage requirement among Han Chinese opioid-dependent patients. MATERIALS & METHODS: Eight SNPs in ABCB1, ARRB2, DRD1 and OPRD1 genes were selected and genotyped using Sequenom MassARRAY platform among 257 methadone maintenance treatment patients. The required information about stable methadone dose, urine analysis for opioid and socio-demographic characteristics was collected. Generalized multifactor dimensionality reduction method was performed to analyze the SNP-SNP interaction. RESULTS: We found that patients carrying the rs529520TG genotype of OPRD1 probably required higher methadone treatment dosage. A 3-locus SNP-SNP interaction pattern (rs1128503 in ABCB1, rs529520 in OPRD1 and rs1045280 in ARRB2) was significantly associated with the methadone dosage requirement (p = 0.029). CONCLUSION: Our results suggested that specific OPRD1 variants and interaction among polymorphisms in ABCB1, OPRD1 and ARRB2 genes contributes to methadone dosage requirement in Han Chinese opioid-dependent patients.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Metadona/administração & dosagem , Polimorfismo de Nucleotídeo Único/genética , Receptores de Dopamina D1/genética , Receptores Opioides delta/genética , beta-Arrestina 2/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Adulto , Analgésicos Opioides/efeitos adversos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Tratamento de Substituição de Opiáceos/métodos , Transtornos Relacionados ao Uso de Opioides/tratamento farmacológico , Transtornos Relacionados ao Uso de Opioides/genética
17.
Oncol Lett ; 13(2): 921-929, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28356979

RESUMO

Sodium butyrate (NaBu), a histone deacetylase inhibitor, has demonstrated anti-tumor effects in several cancers, and is a promising candidate chemotherapeutic agent. However, its roles in nasopharyngeal carcinoma (NPC), an endemic malignant disease in Southern China and Southeast Asia, has rarely been studied. In the present study, MTT assay, colony formation assay, flow cytometry analysis and western blotting were performed to explore the influence of NaBu on NPC cells and its underlying mechanism. NaBu induced morphological changes and inhibited proliferation in 5-8F and 6-10B cells. MTT assay revealed that NaBu was cytotoxic to 5-8F and 6-10B cells in a dose- and time-dependent manner. Furthermore, flow cytometry analysis revealed that NaBu induced obvious cell apoptosis in 5-8F and 6-10B cells due to the activation of the mitochondrial apoptosis axis. In addition, flow cytometry analysis and western blotting demonstrated that NaBu could enhance the Ca2+ influx by promoting store-operated Ca2+ entry (SOCE) in 5-8F and 6-10B cells. Inhibition of SOCE by specific inhibitors or downregulated expression of calcium release-activated calcium channel protein 1 and stromal interaction molecule 1 could counteract the apoptosis of NPC cells induced by NaBu. Thus, the current study revealed that enhanced SOCE and activated mitochondrial apoptosis axis may account for the mechanisms of cytotoxicity of NaBu in NPC cells, and that NaBu serves as a promising chemotherapeutic agent in NPC therapy.

18.
J Zhejiang Univ Sci B ; 17(7): 493-502, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27381726

RESUMO

Willed-movement training has been demonstrated to be a promising approach to increase motor performance and neural plasticity in ischemic rats. However, little is known regarding the molecular signals that are involved in neural plasticity following willed-movement training. To investigate the potential signals related to neural plasticity following willed-movement training, littermate rats were randomly assigned into three groups: middle cerebral artery occlusion, environmental modification, and willed-movement training. The infarct volume was measured 18 d after occlusion of the right middle cerebral artery. Reverse transcription-polymerase chain reaction (PCR) and immunofluorescence staining were used to detect the changes in the signal transducer and activator of transcription 3 (STAT3) mRNA and protein, respectively. A chromatin immunoprecipitation was used to investigate whether STAT3 bound to plasticity-related genes, such as brain-derived neurotrophic factor (BDNF), synaptophysin, and protein interacting with C kinase 1 (PICK1). In this study, we demonstrated that STAT3 mRNA and protein were markedly increased following 15-d willed-movement training in the ischemic hemispheres of the treated rats. STAT3 bound to BDNF, PICK1, and synaptophysin promoters in the neocortical cells of rats. These data suggest that the increased STAT3 levels after willed-movement training might play critical roles in the neural plasticity by directly regulating plasticity-related genes.


Assuntos
Isquemia Encefálica/reabilitação , Terapia por Exercício/métodos , Plasticidade Neuronal/fisiologia , Fator de Transcrição STAT3/fisiologia , Transdução de Sinais , Animais , Isquemia Encefálica/fisiopatologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteínas de Transporte/metabolismo , Proteínas do Citoesqueleto , Masculino , Atividade Motora , Proteínas Nucleares/metabolismo , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Fator de Transcrição STAT3/genética
19.
Oncotarget ; 7(7): 7979-92, 2016 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-26769851

RESUMO

Compelling efficacy on intervention of tumorigenesis by nonsteroidal anti-inflammatory drugs (NSAIDs) has been documented intensively. However, the toxicities related to cyclooxygenase (COX) inhibition resulting in suppression of physiologically important prostaglandins limit their clinical use for human cancer chemoprevention. A novel derivative of the NSAID sulindac sulfide (SS), referred as sulindac sulfide amide (SSA), was recently developed, which lacks COX inhibitory activity, yet shows greater suppressive effect than SS on growth of various cancer cells. In this study, we focus on the inhibitory activity of SSA on breast tumor cell motility, which has not been studied previously. Our results show that SSA treatment at non-cytotoxic concentrations can specifically reduce breast tumor cell motility without influencing tumor cell growth, and the mechanism of action involves the suppression of TGFß signaling by directly blocking Smad2/3 phosphorylation. Moreover, miR-21, a well-documented oncogenic miRNA for promoting tumor cell metastasis, was also found to be involved in inhibitory activity of SSA in breast tumor cell motility through the modulation of TGFß pathway. In conclusion, we demonstrate that a non-COX inhibitory derivative of sulindac can inhibit breast tumor metastasis by a mechanism involving the TGFß/miR-21 signaling axis.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Movimento Celular/efeitos dos fármacos , MicroRNAs/antagonistas & inibidores , Sulindaco/análogos & derivados , Fator de Crescimento Transformador beta/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Western Blotting , Neoplasias da Mama/metabolismo , Proliferação de Células/efeitos dos fármacos , Imunoprecipitação da Cromatina , Feminino , Imunofluorescência , Humanos , Técnicas Imunoenzimáticas , MicroRNAs/genética , Sulindaco/farmacologia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Células Tumorais Cultivadas , Cicatrização
20.
Sci Rep ; 5: 11614, 2015 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-26206082

RESUMO

Lipid raft proteins have been confirmed to be important in cell signal transduction. Some reports have shown that the aberrant expression of lipid raft proteins is associated with malignant phenotypes in some cancers. However, the role of the lipid raft protein flotillin-2 (Flot-2) in nasopharyngeal carcinoma (NPC) remains to be comprehensively characterized. Here, overexpression of Flot-2 in NPC tissues and cell lines was detected by immunostaining, and Flot-2 expression was found to be positively associated with NPC metastasis. Furthermore, inhibiting Flot-2 expression impaired the malignancy of the highly metastatic NPC cell line 5-8F by constraining its growth and proliferation, mobility and migration, and decreasing the capacity of 5-8F cells to metastasize in nude mice. In contrast, forced overexpression of Flot-2 increased the malignancy of 6-10B, a non-metastatic NPC cell line that weakly expresses Flot-2. Moreover, in 5-8F-shFlot-2 cells, which have inhibited Flot-2 expression, the NF-κB and PI3K/Akt3 pathways were inactivated. Subsequently, MMPs expression were decreased, and Foxo1 activity was increased. In addition, enhanced NF-κB and PI3K/Akt3 activities were observed in Flot-2 overexpressing 6-10B cells. Thus, Flot-2 exerts a pro-neoplastic role in NPC and is involved in tumor progression and metastasis. Moreover, Flot-2 exerts its role through NF-κB and PI3K/Akt3 signaling.


Assuntos
Proteínas de Membrana/metabolismo , NF-kappa B/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Animais , Carcinoma , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Proteínas de Membrana/genética , Camundongos , Camundongos Nus , NF-kappa B/genética , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Metástase Neoplásica , Transplante de Neoplasias , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética
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