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1.
Nat Microbiol ; 9(5): 1256-1270, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38649412

RESUMO

Epstein-Barr virus (EBV) can infect both B cells and epithelial cells (ECs), causing diseases such as mononucleosis and cancer. It enters ECs via Ephrin receptor A2 (EphA2). The function of interferon-induced transmembrane protein-1 (IFITM1) in EBV infection of ECs remains elusive. Here we report that IFITM1 inhibits EphA2-mediated EBV entry into ECs. RNA-sequencing and clinical sample analysis show reduced IFITM1 in EBV-positive ECs and a negative correlation between IFITM1 level and EBV copy number. IFITM1 depletion increases EBV infection and vice versa. Exogenous soluble IFITM1 effectively prevents EBV infection in vitro and in vivo. Furthermore, three-dimensional structure prediction and site-directed mutagenesis demonstrate that IFITM1 interacts with EphA2 via its two specific residues, competitively blocking EphA2 binding to EBV glycoproteins. Finally, YTHDF3, an m6A reader, suppresses IFITM1 via degradation-related DEAD-box protein 5 (DDX5). Thus, this study underscores IFITM1's crucial role in blocking EphA2-mediated EBV entry into ECs, indicating its potential in preventing EBV infection.


Assuntos
Antígenos de Diferenciação , Efrina-A2 , Células Epiteliais , Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Receptor EphA2 , Internalização do Vírus , Humanos , Herpesvirus Humano 4/fisiologia , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Células Epiteliais/virologia , Células Epiteliais/metabolismo , Infecções por Vírus Epstein-Barr/virologia , Infecções por Vírus Epstein-Barr/metabolismo , Receptor EphA2/metabolismo , Efrina-A2/metabolismo , Efrina-A2/genética , Antígenos de Diferenciação/metabolismo , Antígenos de Diferenciação/genética , Animais , Células HEK293 , Ligação Proteica , Camundongos , Linhagem Celular
2.
Science ; 383(6683): 659-666, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38330135

RESUMO

Secretory structures in terrestrial plants serve as reservoirs for a variety of secondary metabolites. Among these, the secretory cavity of the Rutaceae family is notable for containing essential oils with a wide range of applications. However, the molecular basis underlying secretory cavity development is unknown. Here, we reveal a molecular framework for Citrus oil gland formation. Using genetic mapping and genome editing, we demonstrated that this process requires LATE MERISTEM IDENTITY1 (LMI1), a key regulator of leaf serration. A conserved GCC box element of the LMI1 promoter recruits DORNROSCHEN-like (DRNL) for transcriptional activation. This DRNL-LMI1 cascade triggers MYC5 activation, facilitating the development of oil glands and the biosynthesis of essential oils. Our findings spotlight cis-regulatory divergence within leaf shape genes, propelling novel functional tissue formation.


Assuntos
Citrus , Óleos Voláteis , Proteínas de Plantas , Fatores de Transcrição , Tricomas , Citrus/genética , Citrus/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Óleos Voláteis/metabolismo , Tricomas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
3.
Am J Transl Res ; 15(1): 82-98, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36777845

RESUMO

OBJECTIVES: Circular RNAs (circRNAs) are involved in carcinogenesis, though their expression profile in renal cell carcinoma (RCC) is uncharacterized. The tumor suppressor gene miR-145-5p is expressed in RCC tissues, but its relationship with circRNAs is unknown. Thus, we aimed to identify differentially expressed circRNAs in RCC tissues and to explore the interaction between these circRNAs and miR-145 in the development of RCC. METHODS: We performed high-throughput sequencing and bioinformatics analyses to examine the expression pattern of circRNAs in RCC. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to functionally annotate differentially expressed circRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was used for sequence verification. Small interfering RNAs were employed to investigate the function and mechanism of circRNAs in RCC. The relationship between miR-145-5p and circRNAs was confirmed using luciferase, RNA immunoprecipitation (RIP), and biotin-coupled probe RNA pull-down assays. RESULTS: Fifty-three circRNAs were significantly and differentially expressed in RCC compared to normal control tissue. Bioinformatic analyses indicated that two significantly upregulated circRNAs, circ-AFF2 and circ-ASAP1, had sequences corresponding to miR-145 response elements. Consistently, the luciferase reporter, RIP, and biotin-coupled probe RNA pull-down assays showed that circ-AFF2 and circ-ASAP1 may repress miR-145 by acting as sponges. circ-AFF2 and circ-ASAP1 were highly expressed in RCC patient-derived tumor samples; their overexpression correlated with poor prognosis and low miR-145 levels. Knockdown of circ-AFF2 or circ-ASAP1 in RCC cell lines inhibited proliferation, underscoring their oncogenic function. A circRNA-miRNA network was constructed for RCC using the differentially expressed circRNAs and projected miRNAs. Candidate genes were verified by RT-qPCR and western blot, indicating that circ-AFF2 and circ-ASAP1 may be connected to RCC proliferation and metastasis. CONCLUSION: circ-AFF2 and circ-ASAP1 were upregulated in RCC and likely promote tumor progression by sponging miR-145. Therefore, both circRNAs should be investigated further as potential diagnostic and therapeutic targets for RCC.

4.
J Transl Med ; 21(1): 40, 2023 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-36681849

RESUMO

BACKGROUND: Current diagnosis tools for prostate cancer (PCa) such as serum PSA detection and prostate biopsy cannot distinguish dormant tumors from invasive malignancies, either be used as prognosis marker for castration resistant prostate cancer (CRPC), the lethal stage of PCa patients. Exosomes have been widely investigated as promising biomarkers for various diseases. We aim to characterize the proteomic and metabolomic profile of exosomes and to evaluate their potential value for the diagnosis of PCa, especially CRPC. We also investigate the functions of some specific exosome biomarkers in the progression of CRPC. METHODS: Integrated proteomics and metabolomics analysis were performed for plasma-derived exosomes collected from tumor-free controls (TFC), PCa and CRPC patients. Expression of specific exosomal proteins were further validated by targeted 4D-parallel reaction monitoring (PRM) mass spectrometry among the three cohorts. Tissue distribution and functional role of exosomal protein LRG1 was studied in clinical PCa tissue samples and cell line models. RESULTS: Three potential exosomal protein markers were identified. The apolipoprotein E level in PCa samples was 1.7-fold higher than that in TFC (receiver operating characteristic value, 0.74). Similarly, the levels of exosome-derived leucine-rich alpha2-glycoprotein 1 (LRG1) and inter-alpha-trypsin inhibitor heavy chain H3 (ITIH3) in the CRPC group were 1.7 and 2.04 times, respectively, higher than those in the PCa group (ROC values, 0.84 and 0.85, respectively), indicating that LRG1 and ITIH3 could serve as predictive markers for CRPC. For metabolomic evaluation of exosomes, a series of differentially expressed metabolites were identified, and a combined metabolite panel showed ROC value of 0.94 for distinguishing PCa from TFC and 0.97 for distinguishing CRPC from PCa. Immunohistochemistry of tissue microarray showed that LRG1 protein was significantly upregulated in advanced prostate cancer and functional assay revealed that ectopic expression of LRG1 can significantly enhance the malignant phenotype of prostate cancer cells. More importantly, PCa cell derived LRG1-overexpressed exosomes remarkably promoted angiogenesis. CONCLUSION: Integration of proteomics and metabolomics data generated proteomic and metabolic signatures of plasma exosomes that may facilitate discrimination of CRPC from PCa and TFC patients, suggesting the potential of exosomal proteins and metabolites as CRPC markers. The study also confirmed the important role of exosomal protein LRG1 in PCa malignant progression.


Assuntos
Exossomos , Neoplasias de Próstata Resistentes à Castração , Humanos , Masculino , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Neoplasias de Próstata Resistentes à Castração/patologia , Proteômica , Próstata/metabolismo , Exossomos/metabolismo
5.
J Exp Bot ; 73(22): 7312-7325, 2022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36070755

RESUMO

Fruit shape is an important trait that attracts consumers, and the regulation of genes related to cell division is crucial for shaping multicellular organs. In Arabidopsis, MYB3R transcription factors, which harbor three imperfect repeats in the N-terminus, control organ growth by regulating cell division. However, the function of MYB3Rs in tomato remains unknown. Here, we characterized tomato SlMYB3R3, which was preferentially expressed in flowers and placed in a subclade with two Arabidopsis cell cycle suppressors (MYB3R3/5). slmyb3r3 knockout mutants were generated using the CRISPR/Cas9 system. Morphological observation of the slmyb3r3 mutants showed that fruits that were elongated and occasionally peanut-like in shape were formed, which was caused by significantly increased cell numbers in the longitudinal direction. Transcriptome and yeast one-hybrid assay results suggested that SlMYB3R3 acted as a suppressor of cell-cycle-related genes by binding to the mitosis-specific activator (MSA) motifs in their promoters. Taken together, knock out of the suppressor SlMYB3R3 leads to elongated fruit, which results from the altered cell division pattern at the ovary stage, by regulating cell-cycle-related genes in an MSA-dependent manner. Our results suggest that SlMYB3R3 and its orthologs have the potential to change fruit shape as part of the molecular breeding of fruit crops.


Assuntos
Arabidopsis , Solanum lycopersicum , Solanum lycopersicum/genética , Frutas/genética , Fatores de Transcrição/genética , Edição de Genes , Divisão Celular , Ciclo Celular/genética
6.
Dis Markers ; 2022: 3780391, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35983409

RESUMO

Background: A rising amount of data demonstrates that the epithelial-mesenchymal transition (EMT) in clear cell renal cell carcinomas (ccRCC) is connected with the advancement of the cancer. In order to understand the role of EMT in ccRCC, it is critical to integrate molecules involved in EMT into prognosis prediction. The objective of this project was to establish a prognosis prediction model using genes associated with EMT in ccRCC. Methods: We acquired the mRNA expression profiles and clinical information about ccRCC from TCGA database. In this study, we measured differentially expressed EMT-related genes (DEEGs) by two comparison groups (tumor versus normal tissues; "stages I-II" versus "stages III-IV" tumor tissues). Based on classification and regression random forest models, we identified the most important DEEGs in predicting prognosis. Afterwards, a risk-score model was created using the identified important DEEGs. The prediction ability of the risk-score model was calculated by the area under the curve (AUC). A nomogram for prognosis prediction was built using the risk-score in combination with clinical factors. Results: Among the 72 DEEGs, the classification and regression random forest models identified six hub genes (DKK1, DLX4, IL6, KCNN4, RPL22L1, and SPDEF), which exhibited the highest importance values in both models. Through the expression of these six hub genes, a novel risk-score was developed for the prognosis prediction of ccRCC. ROC curves showed the risk-score performed well in both the training (0.749) and testing (0.777) datasets. According to the survival analysis, individuals who were separated into high/low-risk groups had statistically different outcomes in terms of prognosis. Besides, the risk-score model also showed outstanding ability in assessing the progression of ccRCC after treatment. In terms of nomogram, the concordance index (C-index) was 0.79. Additionally, we predicted the differences in response to chemotherapy drugs among patients from low- and high-risk groups. Conclusion: Gene signatures related to EMT could be useful in predicting ccRCC prognosis.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Renais/patologia , Transição Epitelial-Mesenquimal/genética , Proteínas de Homeodomínio , Humanos , Neoplasias Renais/patologia , Prognóstico , Fatores de Transcrição/genética
7.
Front Endocrinol (Lausanne) ; 13: 975623, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36034466

RESUMO

Background: Prostate cancer (PCa) is among the leading causes of cancer death worldwide. Ferroptosis refers to an iron-dependent form of regulated cell death and is involved in prostate tumorigenesis. A few ferroptosis-related gene signatures have been developed to predict the prognosis for PCa patients. However, previous signatures were typically established based on biochemical recurrence-free survival, which has proven not to be a good surrogate for overall survival (OS). This study aimed to construct a novel ferroptosis-related gene prognostic index (FRGPI) to predict disease-free survival (DFS) and response to immunotherapy for PCa patients after radical prostatectomy. Methods: Gene expression and clinicopathological data on PCa patients were obtained from the TCGA database. Ferroptosis-related hub genes associated with DFS of PCa patients were identified by an in-depth bioinformatics analysis using a novel and comprehensive algorithm based on functional enrichment, consensus clustering, weighted gene co-expression network analysis (WGCNA), and protein-protein interaction (PPI) network construction. The FRGPI was established on the basis of the genes selected using multivariate cox regression analysis and further validated in two additional PCa cohorts. Next, the clinicopathological, molecular, and immune profiles were characterized and compared between FRGPI-high and FRGPI-low subgroups. Finally, the predictive role of the FRGPI in response to immunotherapy was estimated using a metastatic urothelial cancer cohort treated with an anti-PD-L1 agent. Results: The FRGPI was constructed based on four genes (E2F1, CDC20, TYMS, and NUP85), and FRGPI-high patients had worse DFS than FRGPI-low patients. Multivariate cox regression analysis revealed that FRGPI could act as an independent prognostic factor for PCa patients after radical prostatectomy. A prognostic nomogram comprising the FRGPI and other clinicopathological parameters was established to predict the DFS for PCa patients quantitatively. In addition, comprehensive results demonstrated that high FRGPI scores showed a significantly positive correlation with worse clinicopathological features, higher mutation counts, increased frequency of copy number variations (CNVs), higher homologous recombination deficiency (HRD) and immune scores, higher mRNAsi, and more importantly, enhanced sensitivity to immunotherapy. Conclusions: FRGPI is not only a promising and robust prognostic biomarker, but also a potential indicator of immunotherapeutic outcomes for PCa patients after radical prostatectomy.


Assuntos
Ferroptose , Neoplasias da Próstata , Biomarcadores Tumorais , Variações do Número de Cópias de DNA , Humanos , Imunoterapia , Masculino , Prognóstico
8.
BMC Plant Biol ; 21(1): 356, 2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34325657

RESUMO

BACKGROUND: Proanthocyanidins (PAs) are important plant secondary metabolites that confer flavor, nutritional value, and resistance to pathogens. Persimmon is one of the PA richest crops. Mature fruits can be inedible because of the astringency caused by high PA levels and need to go through a de-astringency treatment before consumption. The molecular basis for PA accumulation is poorly known, particularly transcriptional regulators. We characterised three genotypes ('Luotiantianshi' (LT), 'Mopanshi' (MP), and 'Youhou' (YH)) with different PA accumulation patterns using an approach that combined PacBio full-length sequencing and Illumina-based RNA sequencing to build high-quality full-length transcriptomes. Additionally, we analysed transcriptome dynamics of the three genotypes (LT, MP, and YH) at four key fruit developmental stages. RESULTS: A total of 96,463 transcripts were obtained. We identified 80,075 protein-coding sequences (CDSs), 71,137 simple sequence repeats (SSRs), and 27,845 long noncoding RNAs (lncRNAs). Pearson correlation coefficient (PCC), principal component analysis (PCA), and differentially expressed transcripts (DETs) analyses indicated that the four different developmental stages within a genotype exhibited similar transcriptome activities. A total of 2,164 transcripts specific to each fruit developmental stage were detected. The transcripts specific to early stages were attributed to phenylpropanoid and flavonoid biosynthesis. Co-expression network analyses revealed MEbrown and MEblue modules were strongly associated to PA accumulation. From these two modules, 20 hub TFs are potential regulators for PA accumulation. Among them, Cluster_78388 (SBP protein), Cluster_63454 (bZIP protein), and Cluster_66595 (MYB protein) appear to involve in the PA biosynthesis in Chinese genotypes. CONCLUSIONS: This is the first high-quality reference transcriptome for commercial persimmon. Our work provides insights into the molecular pathways underlying PA accumulation and enhances our global understanding of transcriptome dynamics throughout fruit development.


Assuntos
Diospyros/crescimento & desenvolvimento , Diospyros/genética , Frutas/crescimento & desenvolvimento , Frutas/genética , Proantocianidinas/biossíntese , Proantocianidinas/genética , Fatores de Transcrição/fisiologia , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo
9.
Plant J ; 106(6): 1708-1727, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33835602

RESUMO

Proanthocyanidins (PAs) are phenolic secondary metabolites that contribute to the protection of plant and human health. Persimmon (Diospyros kaki Thunb.) can accumulate abundant PAs in fruit, which cause a strong sensation of astringency. Proanthocyanidins can be classified into soluble and insoluble PAs; the former cause astringency but the latter do not. Soluble PAs can be converted into insoluble PAs upon interacting with acetaldehydes. We demonstrate here that DkMYB14, which regulates the accumulation of PA in persimmon fruit flesh, is a bifunctional transcription factor that acts as a repressor in PA biosynthesis but becomes an activator when involved in acetaldehyde biosynthesis. Interestingly, both functions contribute to the elimination of astringency by decreasing PA biosynthesis and promoting its insolubilization. We show that the amino acid Gly39 in the R2 domain and the ethylene response factor-associated amphiphilic repression-like motif in the C-terminal of DkMYB14 are essential for the regulation of both PA and acetaldehyde synthesis. The repressive function of DkMYB14 was lost after the mutation of either motif, and all activities of DkMYB14 were eliminated following the mutation of both motifs. Our results demonstrate that DkMYB14 functions as both a transcriptional activator and a repressor, directly repressing biosynthesis of PA and promoting its insolubilization, resulting in non-astringency in persimmon.


Assuntos
Diospyros/metabolismo , Frutas/química , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/metabolismo , Proantocianidinas/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Diospyros/genética , Proteínas de Plantas/genética , Sementes , Fatores de Transcrição/genética , Regulação para Cima
10.
FEBS Open Bio ; 11(5): 1487-1496, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-31774623

RESUMO

Bladder cancer is one of the most common malignant tumors of the urinary system, with high morbidity and mortality. At present, the survival rates and prognosis of patients with bladder cancer are still relatively low; thus, there remains a need to improve prognosis by identifying novel targets. Kinesins (kinesin superfamily proteins) are a series of microtubule-based motor proteins that mediate various types of cellular processes. Kinesin family member 3A (KIF3A) is critical for cytoplasm separation in mitosis, and it has been reported to be misexpressed in multiple types of cancer. However, its effects on the progression and development of bladder cancer remain unclear. Herein, we report that KIF3A is highly expressed in human bladder cancer. We identified a significant correlation between KIF3A and clinical features, including clinical stage (P = 0.047), pathological tumor status (P = 0.045), lymph node status (P = 0.041) and metastasis (P = 0.035). KIF3A expression was also correlated with poor prognosis of patients with bladder cancer. Our results further indicated that KIF3A ablation resulted in cell cycle arrest; blocked the proliferation, migration and invasion of bladder cancer cells in vitro; and restrained tumor growth in mice in a microtubule-dependent manner. In summary, our findings suggest that KIF3A is a potential therapeutic target for bladder cancer.


Assuntos
Cinesinas/metabolismo , Neoplasias da Bexiga Urinária/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , China , Feminino , Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Cinesinas/genética , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Prognóstico , Neoplasias da Bexiga Urinária/genética , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Cell Signal ; 25(1): 206-13, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23000344

RESUMO

Here we studied the cellular mechanisms of ursolic acid's anti-bladder cancer ability by focusing on endoplasmic reticulum stress (ER stress) signaling. We show that ursolic acid induces a significant ER stress response in cultured human bladder cancer T24 cells. ER stress inhibitor salubrinal, or PERK silencing, diminishes ursolic acid-induced anti-T24 cell effects. Salubrinal inhibits ursolic acid-induced CHOP expression, Bim ER accumulation and caspase-3 activation in T24 cells. Ursolic acid induces IRE1-TRAF2-ASK1 signaling complex formation to activate pro-apoptotic ASK1-JNK signaling. We suggest that ER stress contributes to ursolic acid's effects against bladder cancer cells.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/metabolismo , MAP Quinase Quinase Quinase 5/metabolismo , Triterpenos/farmacologia , Proteínas Reguladoras de Apoptose/metabolismo , Proteína 11 Semelhante a Bcl-2 , Caspase 3/metabolismo , Linhagem Celular Tumoral , Cinamatos/farmacologia , Endorribonucleases/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator 2 Associado a Receptor de TNF/metabolismo , Tioureia/análogos & derivados , Tioureia/farmacologia , Fator de Transcrição CHOP/metabolismo , Neoplasias da Bexiga Urinária , eIF-2 Quinase/antagonistas & inibidores , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo , Ácido Ursólico
12.
Oncol Lett ; 3(4): 917-920, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22741018

RESUMO

The much improved diagnostic accuracy of computed tomography (CT) and positron emission tomography (PET) has enabled urologists and medical oncologists to identify and treat more patients with metastases to the adrenal glands. The aim of this retrospective study was to analyze the clinical aspects of adrenal metastases in a series of patients and to evaluate the effect of adrenalectomy, by laparoscopic or open resection of adrenal metastases, on the survival of these patients. A total of 47 patients (32 males, 15 females) with metastatic disease in the adrenal glands were included in this study. Type B ultrasound and CT were utilized to diagnose the adrenal metastases. Open resection was performed in certain patients with primary tumor and adrenal metastasis. The results showed that adrenal metastases in these patients had various origins, including lung carcinoma, kidney carcinoma, breast cancer, melanoma and other uncharacterized carcinomas. The median survival of the 37 followed-up patients was 29.7±3.23 months (range, 2-62) after the diagnosis/surgical removal of adrenal metastases. The survival rate of the 31 patients with surgically removed adrenal metastases (average, 34.2±4.7 months; range 2-62) was higher than the survival rates of the 6 patients without surgical resection (average, 6.3±2.7 months; range, 4-8). The results of this study are in support of adrenalectomy for patients with adrenal metastases.

13.
Biochem Biophys Res Commun ; 419(4): 741-7, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22387548

RESUMO

Ursolic acid (UA) has shown the anti-tumor properties against a number of human cancers both in vivo and in vitro, however, its effect in bladder cancer and the corresponding mechanisms of action remain largely unknown. Here we found that UA dose-dependently induced growth inhibition and apoptosis in human bladder cancer T24 cells, and activation of AMP-activated protein kinase (AMPK) may contribute to the process. Our Western-blot results demonstrated a significant AMPK activation after UA treatment in T24 cells. Notably, knockdown of AMPKα by the targeted shRNA largely inhibited UA-induced T24 cell growth inhibition and apoptosis, while an AMPK activator 5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside (AICAR) or a constitutively active form of AMPK mimic UA's effect. We found the ceramide level was increased after UA treatment in T24 cells, and UA-induced AMPK activation and T24 cell apoptosis were inhibited by ceramide synthase inhibitor fumonisin B1, and was enhanced by exogenously adding cell permeable short-chain ceramide (C6), suggesting that ceramide might serve as an upstream signal for AMPK activation. Further, activation of AMPK by UA promoted c-Jun N-terminal kinase (JNK) activation, but inhibited mTOR complex 1 (mTORC1) signaling to cause survivin down-regulation. Our study suggests that activation of AMPK by UA contributes to growth inhibition and apoptosis in human bladder cancer cells.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Triterpenos/farmacologia , Neoplasias da Bexiga Urinária/enzimologia , Proteínas Quinases Ativadas por AMP/genética , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Complexos Multiproteicos , Proteínas/metabolismo , RNA Interferente Pequeno/genética , Ribonucleotídeos/farmacologia , Serina-Treonina Quinases TOR , Ácido Ursólico
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