RESUMO
The PTEN tumor suppressor is frequently mutated or deleted in cancer and regulates glucose metabolism through the PI3K-AKT pathway. However, whether PTEN directly regulates glycolysis in tumor cells is unclear. We demonstrate here that PTEN directly interacts with phosphoglycerate kinase 1 (PGK1). PGK1 functions not only as a glycolytic enzyme but also as a protein kinase intermolecularly autophosphorylating itself at Y324 for activation. The protein phosphatase activity of PTEN dephosphorylates and inhibits autophosphorylated PGK1, thereby inhibiting glycolysis, ATP production, and brain tumor cell proliferation. In addition, knockin expression of a PGK1 Y324F mutant inhibits brain tumor formation. Analyses of human glioblastoma specimens reveals that PGK1 Y324 phosphorylation levels inversely correlate with PTEN expression status and are positively associated with poor prognosis in glioblastoma patients. This work highlights the instrumental role of PGK1 autophosphorylation in its activation and PTEN protein phosphatase activity in governing glycolysis and tumorigenesis.
Assuntos
Neoplasias Encefálicas/enzimologia , Glioblastoma/enzimologia , Glucose/metabolismo , Glicólise , PTEN Fosfo-Hidrolase/metabolismo , Fosfoglicerato Quinase/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Glioblastoma/genética , Glioblastoma/patologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , PTEN Fosfo-Hidrolase/genética , Fosfoglicerato Quinase/genética , Fosforilação , Prognóstico , Transdução de Sinais , Fatores de Tempo , Carga Tumoral , TirosinaRESUMO
Autophagy is crucial for maintaining cell homeostasis. However, the precise mechanism underlying autophagy initiation remains to be defined. Here, we demonstrate that glutamine deprivation and hypoxia result in inhibition of mTOR-mediated acetyl-transferase ARD1 S228 phosphorylation, leading to ARD1-dependent phosphoglycerate kinase 1 (PGK1) K388 acetylation and subsequent PGK1-mediated Beclin1 S30 phosphorylation. This phosphorylation enhances ATG14L-associated class III phosphatidylinositol 3-kinase VPS34 activity by increasing the binding of phosphatidylinositol to VPS34. ARD1-dependent PGK1 acetylation and PGK1-mediated Beclin1 S30 phosphorylation are required for glutamine deprivation- and hypoxia-induced autophagy and brain tumorigenesis. Furthermore, PGK1 K388 acetylation levels correlate with Beclin1 S30 phosphorylation levels and poor prognosis in glioblastoma patients. Our study unearths an important mechanism underlying cellular-stress-induced autophagy initiation in which the protein kinase activity of the metabolic enzyme PGK1 plays an instrumental role and reveals the significance of the mutual regulation of autophagy and cell metabolism in maintaining cell homeostasis.
Assuntos
Autofagossomos/enzimologia , Autofagia , Proteína Beclina-1/metabolismo , Neoplasias Encefálicas/enzimologia , Glioblastoma/enzimologia , Fosfoglicerato Quinase/metabolismo , Acetilação , Animais , Autofagossomos/patologia , Proteína Beclina-1/genética , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Classe III de Fosfatidilinositol 3-Quinases/genética , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Feminino , Glioblastoma/genética , Glioblastoma/patologia , Glutamina/deficiência , Células HEK293 , Humanos , Camundongos Nus , Acetiltransferase N-Terminal A/genética , Acetiltransferase N-Terminal A/metabolismo , Acetiltransferase N-Terminal E/genética , Acetiltransferase N-Terminal E/metabolismo , Fosfoglicerato Quinase/genética , Fosforilação , Ligação Proteica , Interferência de RNA , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo , Transfecção , Carga Tumoral , Hipóxia TumoralRESUMO
BACKGROUND: The development of acquired EGFR-TKI treatment resistance is still a major clinical challenge in the treatment of non-small cell lung cancer (NSCLC). This study aimed to investigate the role of HDAC1/FOXK1/miR-33a signaling in EGFR-TKI resistance. METHODS: The expression levels of miR-33a, HDAC1, and FOXK1 were examined using quantitative polymerase chain reaction (PCR) and bioinformatics analysis. Cell proliferation, migration, and apoptosis were explored by cell number assay, Transwell, and flow cytometry assays, respectively. After overexpression or knockdown of HDAC1, miR-33a expression in the cells, cell functions were tested. Immunoprecipitation and correlation analyses were used to evaluate the interaction between HDAC1 and FOXK1 protein. The tumor-suppressive role of miR-33a was investigated by animal experiments. RESULTS: The suppression of miR-33a increased TKI resistance by affecting cell proliferation, migration, and apoptosis in gefitinib-resistant cells. HDAC1 is the key upstream molecule that inhibits miR-33 expression. HDAC1 upregulation increased gefitinib resistance by its binding to FOXK1 in cells to silence miR-33a expression. MiR-33a overexpression exerts tumor-suppressive effects by negatively regulating ABCB7 and p70S6K1 expression. Moreover, overexpression of miR-33a inhibited tumor growth in a xenograft nude mouse model. CONCLUSIONS: HDAC1/FOXK1 upregulation and miR-33a silencing are new mechanisms of EGFR-TKI resistance in NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Resistencia a Medicamentos Antineoplásicos , Receptores ErbB , Fatores de Transcrição Forkhead , Inativação Gênica , Histona Desacetilase 1 , Neoplasias Pulmonares , MicroRNAs , Inibidores de Proteínas Quinases , Animais , Humanos , Camundongos , Apoptose/efeitos dos fármacos , Apoptose/genética , Sequência de Bases , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptores ErbB/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/genética , Gefitinibe/farmacologia , Gefitinibe/uso terapêutico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desacetilase 1/metabolismo , Histona Desacetilase 1/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/tratamento farmacológico , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêuticoRESUMO
Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been widely used for human non-small-cell lung cancer (NSCLC) treatment. However, acquired resistance to EGFR-TKIs is the major barrier of treatment success, and new resistance mechanism remains to be elucidated. In this study, we found that elevated NADPH oxidase 4 (NOX4) expression was associated with acquired EGFR-TKIs resistance. Gefitinib is the first-generation FDA-approved EGFR-TKI, and osimertinib is the third-generation FDA-approved EGFR-TKI. We demonstrated that NOX4 knockdown in the EGFR-TKI resistant cells enabled the cells to become sensitive to gefitinib and osimertinib treatment, while forced expression of NOX4 in the sensitive parental cells was sufficient to induce resistance to gefitinib and osimertinib in the cells. To elucidate the mechanism of NOX4 upregulation in increasing TKIs resistance, we found that knockdown of NOX4 significantly down-regulated the expression of transcription factor YY1. YY1 bound directly to the promoter region of IL-8 to transcriptionally activate IL-8 expression. Interestingly, knockdown of NOX4 and IL-8 decreased programmed death ligand 1 (PD-L1) expression, which provide new insight on TKIs resistance and immune escape. We found that patients with higher NOX4 and IL-8 expression levels showed a shorter survival time compared to those with lower NOX4 and IL-8 expression levels in response to the anti-PD-L1 therapy. Knockdown of NOX4, YY1 or IL-8 alone inhibited angiogenesis and tumor growth. Furthermore, the combination of NOX4 inhibitor GKT137831 and gefitinib had synergistic effect to inhibit cell proliferation and tumor growth and to increase cellular apoptosis. These findings demonstrated that NOX4 and YY1 were essential for mediating the acquired EGFR-TKIs resistance. IL-8 and PD-L1 are two downstream targets of NOX4 to regulate TKIs resistance and immunotherapy. These molecules may be used as potential new biomarkers and therapeutic targets for overcoming TKIs resistance in the future.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinogênese , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB , Gefitinibe/farmacologia , Gefitinibe/uso terapêutico , Interleucina-8/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação , NADPH Oxidase 4/genética , /farmacologiaRESUMO
Hexavalent chromium [Cr(VI)] is one of the most common environmental contaminants due to its tremendous industrial applications, but its effects and mechanism remain to be investigated. Our previous studies showed that Cr(VI) exposure caused malignant transformation and tumorigenesis. This study showed that glycolytic proteins HK2 and LDHA levels were statistically significant changed in blood samples of Cr(VI)-exposed workers and in Cr-T cells compared to the control subjects and parental cells. HK2 and LDHA knockdown inhibited cell proliferation and angiogenesis, and higher HK2 and LDHA expression levels are associated with advanced stages and poor prognosis of lung cancer. We found that miR-218 levels were significantly decreased and miR-218 directly targeted HK2 and LDHA for inhibiting their expression. Overexpression of miR-218 inhibited glucose consumption and lactate production in Cr-T cells. Further study found that miR-218 inhibited tumor growth and angiogenesis by decreasing HK2 and LDHA expression in vivo. MiR-218 levels were negatively correlated with HK2 and LDHA expression levels and cancer development in human lung and other cancers. These results demonstrated that miR-218/HK2/LDHA pathway is vital for regulating Cr(VI)-induced carcinogenesis and human cancer development.
Assuntos
Carcinogênese , Cromo , Hexoquinase , Neoplasias Pulmonares , MicroRNAs , Regulação para Cima , MicroRNAs/genética , Humanos , Cromo/toxicidade , Hexoquinase/genética , Hexoquinase/metabolismo , Carcinogênese/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Prognóstico , Animais , Proliferação de Células/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Exposição Ocupacional/efeitos adversos , Camundongos , IsoenzimasRESUMO
The interplay among cigarette smoking status, oral microbiota, and cardiometabolic health is poorly understood. We aimed to examine the association of cigarette smoking status with oral microbiota and to assess the association of the identified microbial features with cardiometabolic risk factors in a Chinese population. This study included 587 participants within the Central China Cohort, including 111 smokers and 476 non-smokers, and their oral microbiota was profiled by 16S rRNA sequencing. Both oral microbial alpha- and beta-diversity were distinct between smokers and non-smokers (p < 0.05). With adjustment for sociodemographics, alcohol and tea drinking, tooth brushing frequency, and body mass index, the relative abundance of nine genera and 26 pathways, including the genus Megasphaera and two pathways involved in inositol degradation which have potentially adverse effects on cardiometabolic health, was significantly different between two groups (FDR q < 0.20). Multiple microbial features related to cigarette smoking were found to partly mediate the associations of cigarette smoking with serum triglycerides and C-reactive protein levels (p-mediation < 0.05). In conclusion, cigarette smoking status may have impacts on the oral microbial features, which may partially mediate the associations of cigarette smoking and cardiometabolic health.
Assuntos
Doenças Cardiovasculares , Fumar Cigarros , Microbiota , Boca , Adulto , Humanos , Bactérias/genética , Doenças Cardiovasculares/epidemiologia , Fumar Cigarros/efeitos adversos , População do Leste Asiático , RNA Ribossômico 16S/genética , Boca/microbiologiaRESUMO
OBJECTS: Joint morphology is a risk factor for hip osteoarthritis (HOA) and could explain ethnic differences in HOA prevalence. Therefore, we aimed to compare the prevalence of radiographic HOA (rHOA) and hip morphology between the predominantly White UK Biobank (UKB) and exclusively Chinese Shanghai Changfeng (SC) cohorts. METHODS: Left hip iDXA scans were used to quantify rHOA, from a combination of osteophytes (grade ≥1) and joint space narrowing (grade ≥1), and hip morphology. Using an 85-point Statistical Shape Model (SSM) we evaluated cam (alpha angle ≥60°) and pincer (lateral centre-edge angle (LCEA) ≥45°) morphology and acetabular dysplasia (LCEA <25°). Diameter of femoral head (DFH), femoral neck width (FNW), and hip axis length (HAL) were also obtained from these points. Results were adjusted for differences in age, height, and weight and stratified by sex. RESULTS: Complete data were available for 5924 SC and 39,020 White UKB participants with mean ages of 63.4 and 63.7 years old. rHOA prevalence was considerably lower in female (2.2% versus 13.1%) and male (12.0% and 25.1%) SC compared to UKB participants. Cam morphology, rarely seen in females, was less common in SC compared with UKB males (6.3% versus 16.5%). Composite SSM modes, scaled to the same overall size, revealed SC participants to have a wider femoral head compared to UKB participants. FNW and HAL were smaller in SC compared to UKB, whereas DFH/FNW ratio was higher in SC. CONCLUSIONS: rHOA prevalence is lower in Chinese compared with White individuals. Several differences in hip shape were observed, including frequency of cam morphology, FNW, and DFH/FNW ratio. These characteristics have previously been identified as risk factors for HOA and may contribute to observed ethnic differences in HOA prevalence.
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Hexavalent chromium [Cr(VI)] is a well-known environmental carcinogen. Recent studies revealed that chronic exposure of human bronchial epithelial cells (BEAS-2B, B2B) to Cr(VI) activated several signaling pathways and induced cell malignant transformation and tumor growth. However, new mechanisms of Cr(VI) in inducing carcinogenesis remains to be elucidated. This study showed that miR-199a expression levels were significantly lower in Cr(VI)-transformed Cr-T cells. By using the mouse model, the expression levels of miR-199a were significantly decreased in blood samples and lung tissues of mice intranasally exposed to Cr(VI) for 12 weeks compared to the solvent exposure control. Overexpression of miR-199a inhibited tube formation and angiogenesis. C-X-C motif chemokine ligand 8 (CXCL8, IL8) levels were significantly higher in blood samples of Cr (VI)-exposed workers compared to normal workers, and forced expression of miR-199a in the cells suppressed IL8 levels. miR-199a suppression induced expression of hypoxia-inducible factor 1α (HIF-1α) and nuclear factor kappa B (NF-κB) p65 to increase IL8 expression. With animal experiment, the results showed that miR-199a overexpression inhibited tumor growth and angiogenesis through inhibiting IL8, HIF-1α and NF-κB p65 expression in vivo. These results show that miR-199a/IL8 pathway is important in Cr(VI)-induced carcinogenesis and angiogenesis.
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MicroRNAs (miRNAs) are small endogenous non-coding RNAs that regulate cancer initiation, development, angiogenesis, and therapeutic resistance. Metal exposure widely occurs through air, water, soil, food, and industrial contaminants. Hundreds of millions of people may have metal exposure associated with toxicity, serious health problems, and cancer occurrence. Metal exposure is found to induce oxidative stress, DNA damage and repair, and activation of multiple signaling pathways. However, molecular mechanisms of metal-induced carcinogenesis remain to be elucidated. Recent studies demonstrated that the exposure of metals such as arsenic, hexavalent chromium, cadmium, and nickel caused dysregulation of microRNAs that are implicated to play an important role in cell transformation, tumor growth and angiogenesis. This review focuses on the recent studies that show metal-induced miRNA dysregulation and underlined mechanisms in cell malignant transformation, angiogenesis and tumor growth.
Assuntos
Transformação Celular Neoplásica/induzido quimicamente , Metais/efeitos adversos , MicroRNAs , Neovascularização Patológica/induzido quimicamente , Animais , HumanosRESUMO
The diverse repertoires of cellular mechanisms that progress certain cancer types are being uncovered by recent research and leading to more effective treatment options. Ovarian cancer (OC) is among the most difficult cancers to treat. OC has limited treatment options, especially for patients diagnosed with late-stage OC. The dysregulation of miRNAs in OC plays a significant role in tumorigenesis through the alteration of a multitude of molecular processes. The development of OC can also be due to the utilization of endogenously derived reactive oxygen species (ROS) by activating signaling pathways such as PI3K/AKT and MAPK. Both miRNAs and ROS are involved in regulating OC angiogenesis through mediating multiple angiogenic factors such as hypoxia-induced factor (HIF-1) and vascular endothelial growth factor (VEGF). The NAPDH oxidase subunit NOX4 plays an important role in inducing endogenous ROS production in OC. This review will discuss several important miRNAs, NOX4, and ROS, which contribute to therapeutic resistance in OC, highlighting the effective therapeutic potential of OC through these mechanisms.
Assuntos
MicroRNAs , Neoplasias Ovarianas , Carcinoma Epitelial do Ovário , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia , MicroRNAs/genética , NADPH Oxidases/metabolismo , Neovascularização Patológica/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Fosfatidilinositol 3-Quinases , Espécies Reativas de Oxigênio/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Tyrosine kinase inhibitor (TKI) therapy has greatly improved lung cancer survival in patients with epidermal growth factor receptor (EGFR) mutations. However, the development of TKI-acquired resistance is the major problem to be overcome. In this study, we found that miR-196a expression was greatly induced in gefitinib-resistant lung cancer cells. To understand the role and mechanism of miR-196a in TKI resistance, we found that miR-196a-forced expression alone increased cell resistance to gefitinib treatment in vitro and in vivo by inducing cell proliferation and inhibiting cell apoptosis. We identified the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) bound to the promoter region of miR-196a and induced miR-196a expression at the transcriptional level. NRF2-forced expression also significantly increased expression levels of miR-196a, and was an upstream inducer of miR-196a to mediate gefitinib resistance. We also found that glycolipid transfer protein (GLTP) was a functional direct target of miR-196a, and downregulation of GLTP by miR-196a was responsible for gefitinib resistance. GLTP overexpression alone was sufficient to increase the sensitivity of lung cancer cells to gefitinib treatment. Our studies identified a new role and mechanism of NRF2/miR-196a/GLTP pathway in TKI resistance and lung tumor development, which may be used as a new biomarker (s) for TKI resistance or as a new therapeutic target in the future.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proteínas de Transporte/genética , Resistencia a Medicamentos Antineoplásicos , Gefitinibe/farmacologia , MicroRNAs/genética , Fator 2 Relacionado a NF-E2/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/fisiopatologia , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Gefitinibe/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Nus , MicroRNAs/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The aim of this study was to develop a noninvasive serological diagnostic approach in identifying and evaluating a panel of candidate autoantibodies to tumor-associated antigens (TAAs) based on protein microarray technology for early detection of ovarian cancer (OC). Protein microarray based on 154 proteins encoded by 138 cancer driver genes was used to screen candidate anti-TAA autoantibodies in a discovery cohort containing 17 OC and 27 normal controls (NC). Indirect enzyme-linked immunosorbent assay (ELISA) was used to detect the content of candidate anti-TAA autoantibodies in sera from 140 subjects in the training cohort. Differential anti-TAA autoantibodies were further validated in the validation cohort with 328 subjects. Subsequently, 112 sera from the patients with ovarian benign diseases with 104 OC sera and 104 NC sera together were recruited to identify the specificity of representative autoantibodies to OC among ovarian diseases. Five TAAs (GNAS, NPM1, FUBP1, p53, and KRAS) were screened out in the discovery phase, in which four of them presented higher levels in OC than controls (P < .05) in the training cohort, which was consistent with the result in the subsequent validation cohort. An optimized panel of three anti-TAA (GNAS, p53, and NPM1) autoantibodies was identified to have relatively high sensitivity (51.2%), specificity (86.0%), and accuracy (68.6%), respectively. This panel can identify 51% of OC patients with CA125 negative. This study supports our assumption that anti-TAA autoantibodies can be considered as potential diagnostic biomarkers for detection of OC; especially a panel of three anti-TAA autoantibodies could be a good tool in immunodiagnosis of OC.
Assuntos
Antígenos de Neoplasias/imunologia , Autoanticorpos/imunologia , Biomarcadores Tumorais/imunologia , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/imunologia , Adulto , Idoso , Autoanticorpos/sangue , Biomarcadores Tumorais/sangue , Feminino , Humanos , Pessoa de Meia-Idade , Nucleofosmina , Neoplasias Ovarianas/sangue , Análise Serial de Proteínas/métodos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Cyclin-dependent kinases 2/4/6 (CDK2/4/6) play critical roles in cell cycle progression, and their deregulations are hallmarks of hepatocellular carcinoma (HCC). METHODS: We used the combination of computational and experimental approaches to discover a CDK2/4/6 triple-inhibitor from FDA approved small-molecule drugs for the treatment of HCC. RESULTS: We identified vanoxerine dihydrochloride as a new CDK2/4/6 inhibitor, and a strong cytotoxicdrugin human HCC QGY7703 and Huh7 cells (IC50: 3.79 µM for QGY7703and 4.04 µM for Huh7 cells). In QGY7703 and Huh7 cells, vanoxerine dihydrochloride treatment caused G1-arrest, induced apoptosis, and reduced the expressions of CDK2/4/6, cyclin D/E, retinoblastoma protein (Rb), as well as the phosphorylation of CDK2/4/6 and Rb. Drug combination study indicated that vanoxerine dihydrochloride and 5-Fu produced synergistic cytotoxicity in vitro in Huh7 cells. Finally, in vivo study in BALB/C nude mice subcutaneously xenografted with Huh7 cells, vanoxerine dihydrochloride (40 mg/kg, i.p.) injection for 21 days produced significant anti-tumor activity (p < 0.05), which was comparable to that achieved by 5-Fu (10 mg/kg, i.p.), with the combination treatment resulted in synergistic effect. Immunohistochemistry staining of the tumor tissues also revealed significantly reduced expressions of Rb and CDK2/4/6in vanoxerinedihydrochloride treatment group. CONCLUSIONS: The present study isthe first report identifying a new CDK2/4/6 triple inhibitor vanoxerine dihydrochloride, and demonstrated that this drug represents a novel therapeutic strategy for HCC treatment.
Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Quinase 2 Dependente de Ciclina/antagonistas & inibidores , Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Fluoruracila/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Piperazinas/administração & dosagem , Animais , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quinase 2 Dependente de Ciclina/metabolismo , Quinase 4 Dependente de Ciclina/metabolismo , Quinase 6 Dependente de Ciclina/metabolismo , Regulação para Baixo , Sinergismo Farmacológico , Feminino , Fluoruracila/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Injeções Subcutâneas , Neoplasias Hepáticas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação/efeitos dos fármacos , Piperazinas/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Chemoresistance is a critical risk problem for breast cancer treatment. However, mechanisms by which chemoresistance arises remains to be elucidated. The expression of T-box transcription factor 15 (TBX-15) was found downregulated in some cancer tissues. However, role and mechanism of TBX15 in breast cancer chemoresistance is unknown. Here we aimed to identify the effects and mechanisms of TBX15 in doxorubicin resistance in breast cancer. METHODS: As measures of Drug sensitivity analysis, MTT and IC50 assays were used in DOX-resistant breast cancer cells. ECAR and OCR assays were used to analyze the glycolysis level, while Immunoblotting and Immunofluorescence assays were used to analyze the autophagy levels in vitro. By using online prediction software, luciferase reporter assays, co-Immunoprecipitation, Western blotting analysis and experimental animals models, we further elucidated the mechanisms. RESULTS: We found TBX15 expression levels were decreased in Doxorubicin (DOX)-resistant breast cancer cells. Overexpression of TBX15 reversed the DOX resistance by inducing microRNA-152 (miR-152) expression. We found that KIF2C levels were highly expressed in DOX-resistant breast cancer tissues and cells, and KIF2C was a potential target of miR-152. TBX15 and miR-152 overexpression suppressed autophagy and glycolysis in breast cancer cells, while KIF2C overexpression reversed the process. Overexpression of KIF2C increased DOX resistance in cancer cells. Furthermore, KIF2C directly binds with PKM2 for inducing the DOX resistance. KIF2C can prevent the ubiquitination of PKM2 and increase its protein stability. In addition, we further identified that Domain-2 of KIF2C played a major role in the binding with PKM2 and preventing PKM2 ubiquitination, which enhanced DOX resistance by promoting autophagy and glycolysis. CONCLUSIONS: Our data identify a new mechanism by which TBX15 abolishes DOX chemoresistance in breast cancer, and suggest that TBX15/miR-152/KIF2C axis is a novel signaling pathway for mediating DOX resistance in breast cancer through regulating PKM2 ubiquitination and decreasing PKM2 stability. This finding suggests new therapeutic target and/or novel strategy development for cancer treatment to overcome drug resistance in the future.
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Motivation: Alignment-free sequence comparison methods can compute the pairwise similarity between a huge number of sequences much faster than sequence-alignment based methods. Results: We propose a new non-parametric alignment-free sequence comparison method, called K2, based on the Kendall statistics. Comparing to the other state-of-the-art alignment-free comparison methods, K2 demonstrates competitive performance in generating the phylogenetic tree, in evaluating functionally related regulatory sequences, and in computing the edit distance (similarity/dissimilarity) between sequences. Furthermore, the K2 approach is much faster than the other methods. An improved method, K2*, is also proposed, which is able to determine the appropriate algorithmic parameter (length) automatically, without first considering different values. Comparative analysis with the state-of-the-art alignment-free sequence similarity methods demonstrates the superiority of the proposed approaches, especially with increasing sequence length, or increasing dataset sizes. Availability and implementation: The K2 and K2* approaches are implemented in the R language as a package and is freely available for open access (http://community.wvu.edu/daadjeroh/projects/K2/K2_1.0.tar.gz). Contact: yueljiang@163.com. Supplementary information: Supplementary data are available at Bioinformatics online.
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Filogenia , Análise de Sequência de DNA/métodos , Software , Algoritmos , Animais , Alinhamento de SequênciaRESUMO
Inorganic arsenic is an environmental carcinogen that poses a major global public health risk. A high percentage of drinking water from wells in the U.S. contains higher-than-normal levels of arsenic, suggesting an increased risk of arsenic-induced deleterious effects. In addition to primary preventive measures, therapeutic strategies need to effectively address and integrate multiple molecular mechanisms underlying arsenic-induced carcinogenesis. We previously showed that the loss of miR-199a-5p in arsenic-transformed cells is pivotal to promote arsenic-induced angiogenesis and tumor growth in lung epithelial cells. In this study, we further showed that subacute or chronic exposure to arsenic diminished miR-199a-5p levels largely due to DNA methylation, which was achieved by increased DNA methyltransferase-1 (DNMT1) activity, mediated by the formation of specific protein 1 (Sp1)/DNMT1 complex. In addition to the DNA hypermethylation, arsenic exposure also repressed miR-199a transcription through a transcriptional repressor Sp1. We further identified an association between miR-199a-5p repression and the arsenic-mediated energy metabolic shift, as reflected by mitochondria defects and a switch to glycolysis, in which a glycolytic enzyme pyruvate kinase 2 (PKM2) was a functional target of miR-199a-5p. Taken together, the repression of miR-199a-5p through both Sp1-dependent DNA methylation and Sp1 transcriptional repression promotes an arsenic-mediated metabolic shift from mitochondria respiration to aerobic glycolysis via PKM2.
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Arsênio/efeitos adversos , Metilação de DNA/efeitos dos fármacos , MicroRNAs/genética , Fator de Transcrição Sp1/genética , Ativação Metabólica/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Linhagem Celular , Glicólise/efeitos dos fármacos , HumanosRESUMO
Hexavalent chromium [Cr(VI)] is a known occupational and environmental contaminant and carcinogen, but new mechanisms of Cr(VI)-induced carcinogenesis remain to be elucidated. In this study, we found that expression of miR-143 is decreased, whereas that of Interleukin 6 (IL-6) is increased in blood samples of Cr(VI)-exposing workers compared with corresponding unexposed workers. In addition, IL-6 was increased in human bronchial epithelial cells (BEAS-Cr) exposed to Cr(VI) compared with unexposed BEAS-2B cells. To further investigate the mechanisms by which Cr(VI) promotes these changes, we assessed the effects of miR-143 on gene expression and found that miR-143 suppressed expression of IL-6, HIF-1α and NF-κB p65, and that inhibiting miR-143 promoted expression of IL-6, HIF-1α and NF-κB p65. Interestingly, IL-6 regulated expression of HIF-1α, and HIF-1α transcriptionally regulated expression of IL-6. Experiments in animals showed that miR-143 inhibited tumor growth and angiogenesis by regulating IL-6/HIF-1α and downstream signaling pathways in vivo. These outcomes support the hypothesis that the miR-143/IL-6/HIF-1α pathway functions to regulate Cr(VI)-induced carcinogenesis.
Assuntos
Proliferação de Células/efeitos dos fármacos , Cromo/efeitos adversos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Interleucina-6/genética , MicroRNAs/genética , Fator de Transcrição RelA/genética , Animais , Brônquios/efeitos dos fármacos , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Linhagem Celular , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Neoplasias Pulmonares/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , NF-kappa B/genética , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
BACKGROUND: Alignment-free sequence similarity analysis methods often lead to significant savings in computational time over alignment-based counterparts. RESULTS: A new alignment-free sequence similarity analysis method, called SSAW is proposed. SSAW stands for Sequence Similarity Analysis using the Stationary Discrete Wavelet Transform (SDWT). It extracts k-mers from a sequence, then maps each k-mer to a complex number field. Then, the series of complex numbers formed are transformed into feature vectors using the stationary discrete wavelet transform. After these steps, the original sequence is turned into a feature vector with numeric values, which can then be used for clustering and/or classification. CONCLUSIONS: Using two different types of applications, namely, clustering and classification, we compared SSAW against the the-state-of-the-art alignment free sequence analysis methods. SSAW demonstrates competitive or superior performance in terms of standard indicators, such as accuracy, F-score, precision, and recall. The running time was significantly better in most cases. These make SSAW a suitable method for sequence analysis, especially, given the rapidly increasing volumes of sequence data required by most modern applications.
Assuntos
Algoritmos , Biologia Computacional/métodos , Análise de Sequência de DNA/métodos , Análise de Sequência de Proteína/métodos , Homologia de Sequência , Análise de Ondaletas , Análise por Conglomerados , HumanosRESUMO
BACKGROUND: Estrogen plays a critical role in breast cancer (BC) progression through estrogen receptor (ER)-mediated gene regulation. Emerging studies suggest that the malignant progress of BC cells is influenced by the cross talk between microRNAs (miRNAs) and ER-α signaling. However, the mechanism and functional linkage between estrogen and miRNAs remain unclear. METHODS: The expression levels of miR-196a and SPRED1 in BC were tested by qRT-PCR in 46 paired BC and adjacent tissues and by the GEO datasets. The role of miR-196a in estrogen-induced BC development was examined by CCK-8 assay, wound healing assay, Matrigel invasion assay and tumorigenicity assay in nude mice. The binding site of ER-α in miR-196a promoter region was analyzed by ChIP-seq, ChIP assay and luciferase reporter assay. The potential targets of miR-196a in BC cells were explored using the luciferase reporter assay and western blot analysis, and the correlation between miR-196a and SPRED1 was analyzed by Spearman's correlation analysis in BC specimens and GEO dataset. TCGA BRCA data was used to characterize the ESR1 signatures according to MSigDB gene set. RESULTS: The expression levels of miR-196a were higher in ER-positive (ER+) breast tumors compared to ER-negative (ER-) tumor tissue samples. Besides, miR-196a was involved in estrogen-induced BC cell proliferation, migration and invasion. Notably, the up-regulation of miR-196a was mediated by a direct interaction with estrogen receptor α (ER-α) but not estrogen receptor ß (ER-ß) in its promoter region, and miR-196a expression levels were positively correlated to ER-α signature scores. Furthermore, SPRED1 was a new direct target of miR-196a which participated in miR-196a-promoted BC development and was suppressed by ligand-activated ER-α signal pathway. Finally, forced expression of miR-196a induced tumor growth of MCF7 cells, while inhibition of miR-196a significantly suppressed the tumor progress in vivo. CONCLUSIONS: Overall, the identification of estrogen/miR-196a/SPRED1 cascade will shed light on new molecular mechanism of estrogen signaling in BC development and therapy.
Assuntos
Neoplasias da Mama/patologia , Estrogênios/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , MicroRNAs/genética , Regulação para Cima , Proteínas Adaptadoras de Transdução de Sinal , Animais , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptor alfa de Estrogênio/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , MicroRNAs/química , Metástase Neoplásica , Transplante de Neoplasias , Transdução de SinaisRESUMO
OBJECTIVES: Taxoid 10ß-O-acetyl transferase (DBAT) was redesigned to enhance its catalytic activity and substrate preference for baccatin III and taxol biosynthesis. RESULTS: Residues H162, D166 and R363 were determined as potential sites within the catalytic pocket of DBAT for molecular docking and site-directed mutagenesis to modify the activity of DBAT. Enzymatic activity assays revealed that the kcat/KM values of mutant H162A/R363H, D166H, R363H, D166H/R363H acting on 10-deacetylbaccatin III were about 3, 15, 26 and 60 times higher than that of the wild type of DBAT, respectively. Substrate preference assays indicated that these mutants (H162A/R363H, D166H, R363H, D166H/R363H) could transfer acetyl group from unnatural acetyl donor (e.g. vinyl acetate, sec-butyl acetate, isobutyl acetate, amyl acetate and isoamyl acetate) to 10-deacetylbaccatin III. CONCLUSION: Taxoid 10ß-O-acetyl transferase mutants with redesigned active sites displayed increased catalytic activities and modified substrate preferences, indicating their possible application in the enzymatic synthesis of baccatin III and taxol.