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1.
J Chem Phys ; 151(12): 125101, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31575173

RESUMO

Gene regulation is one of the most important fundamental biological processes in living cells. It involves multiple protein molecules that locate specific sites on DNA and assemble gene initiation or gene repression multimolecular complexes. While the protein search dynamics for DNA targets has been intensively investigated, the role of intermolecular interactions during the genetic activation or repression remains not well quantified. Here, we present a simple one-dimensional model of target search for two interacting molecules that can reversibly form a dimer molecular complex, which also participates in the search process. In addition, the proteins have finite residence times on specific target sites, and the gene is activated or repressed when both proteins are simultaneously present at the target. The model is analyzed using first-passage analytical calculations and Monte Carlo computer simulations. It is shown that the search dynamics exhibit a complex behavior depending on the strength of intermolecular interactions and on the target residence times. We also found that the search time shows a nonmonotonic behavior as a function of the dissociation rate for the molecular complex. Physical-chemical arguments to explain these observations are presented. Our theoretical approach highlights the importance of molecular interactions in the complex process of gene activation/repression by multiple transcription factor proteins.


Assuntos
DNA/química , Modelos Químicos , Simulação por Computador , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Cinética , Método de Monte Carlo , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
2.
Zhonghua Gan Zang Bing Za Zhi ; 27(9): 693-697, 2019 Sep 20.
Artigo em Chinês | MEDLINE | ID: mdl-31594094

RESUMO

Objective: To investigate the effect and mechanism of XTP4 gene in apoptotic hepatoblastoma HepG2 cell line. Methods: HepG2 cells were transiently transfected with small interfering RNA of XTP4 genes, plasmid pcDNA3.1/myc-His(-) A-XTP4, and hepatitis B virus X protein transactivated x gene 4 (HBX protein trans-activate gene4, XTP4) and their respective negative controls. After 48h, the overexpression and interference expression condition of XTP4 in HepG2 cells were detected by Western blot. HepG2 cells apoptosis was detected by flow cytometry. The expression levels of apoptosis-related proteins P53, Bcl-2, Bax and Caspase-3 in HepG2 cells were detected by Western blot, and Bcl-2/Bax ratio was calculated. The chemiluminescence assay was used to detect activity of caspase-3 in HepG2 cells. The measured data were presented as (x ± s), and independent sample t-test was used for comparison between the two groups. Results: HepG2 cells had successfully achieved the overexpression and interference expression of XTP4 protein. Compared with the control group, the overexpression of XTP4 in HepG2 cells had significantly decreased the number of apoptotic cells (P < 0.05), and increased Bcl-2/Bax (P < 0.05) ratio, but decreased the expression of P53 protein (P < 0.05). The protein expression of Caspase-3 and activity of caspase-3 was decreased (P < 0.05). However, interference with XTP4 expression in HepG2 cells had significantly increased the number of apoptotic cells (P < 0.05) and decreased Bcl-2/Bax (P < 0.05) ratio, but increased the expression of P53 protein (P < 0.05). The protein expression of Caspase-3 and activity of caspase-3 was increased (P<0.05). Conclusion: In HepG2 apoptosis XTP4 has inhibitory effect, and its effect on inhibiting HepG2 apoptosis may be achieved by regulating the Bcl-2/Bax ratio, and the P53 protein may be involved.


Assuntos
Apoptose , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Transativadores/metabolismo , Caspase 3/metabolismo , Células Hep G2 , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transfecção , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
3.
Anticancer Res ; 39(9): 4965-4970, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519602

RESUMO

BACKGROUND/AIM: Colonic crypts with normal epithelium albeit with corrupted shapes (CCS) were previously found beneath nonpolypoid adenomas (NPA). This study aimed to analyze the distribution of proliferating cells (PC) and p53-up-regulated cells in CCS. MATERIALS AND METHODS: Sections from 48 NPA were immunostained with the proliferating-marker Ki67 and against the tumor-suppressor protein p53. RESULTS: Asymmetric-haphazardly distributed PC were found in 87.5% of the NPA, continuous PC-domains in 8.3%, asymmetric-haphazardly distributed single PC in 4.2% and p53-up-regulated cells in 29.2%. In 12 controls, the normal-shaped crypts revealed symmetrically-distributed PC-domains in their lower thirds, and no p53-up-regulated cells. CONCLUSION: The normal epithelium that lines the CCS below NPA, thrives with relocated PC-domains, and with occasional p53-up-regulated cells. These findings strongly suggest that the normal epithelium of CCS beneath NPA might harbor somatic mutations. The accretion of putative mutated CCS might play an important role in the evolution of nonpolypoid adenomas in the human colon.


Assuntos
Adenoma/genética , Neoplasias do Colo/genética , Regulação Neoplásica da Expressão Gênica , Mucosa Intestinal/metabolismo , Proteína Supressora de Tumor p53/genética , Adenoma/metabolismo , Adenoma/patologia , Proliferação de Células , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Humanos , Fenótipo , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima
4.
J Cancer Res Clin Oncol ; 145(10): 2413-2422, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31492983

RESUMO

PURPOSE: Polo-like kinase 4 (PLK4) is a serine/threonine protein kinase that regulates centriole duplication. PLK4 deregulation causes centrosome number abnormalities, mitotic defects, chromosomal instability and, consequently, tumorigenesis. Therefore, PLK4 has emerged as a therapeutic target for the treatment of multiple cancers. In this review, we summarize the critical role of centrosome amplification and PLK4 in cancer. We also highlight recent advances in the development of PLK4 inhibitors and discuss potential combination therapies for cancer. METHODS: The relevant literature from PubMed is reviewed in this article. The ClinicalTrials.gov database was searched for clinical trials related to the specific topic. RESULTS: PLK4 is aberrantly expressed in multiple cancers and has prognostic value. Targeting PLK4 with inhibitors suppresses tumor growth in vitro and in vivo. CONCLUSIONS: PLK4 plays an important role in centrosome amplification and tumor progression. PLK4 inhibitors used alone or in combination with other drugs have shown significant anticancer efficacy, suggesting a potential therapeutic strategy for cancer. The results of relevant clinical trials await evaluation.


Assuntos
Biomarcadores Tumorais , Neoplasias/etiologia , Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Centrossomo/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Terapia de Alvo Molecular , Metástase Neoplásica , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Especificidade de Órgãos/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Relação Estrutura-Atividade , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
5.
Adv Exp Med Biol ; 1155: 533-541, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468429

RESUMO

Taurine displays anti-tumor activity in some kinds of human cancers. However, the underlying mechanisms are poorly understood. Epstein-Barr virus-related nasopharyngeal carcinoma (NPC) is a distinctive type of head and neck cancer in Southeast Asia with the highest incidence in South China. We examined an apoptosis-inducing effect of taurine against NPC cells (HK1 and HK1-EBV) to clarify the mechanisms of anti-tumor effects of taurine by immunocytochemical methods. We observed that taurine induced cleavage of caspase-9/3 in a concentration-dependent manner, suggesting the involvement of mitochondrial apoptotic signals. Both PTEN and p53 activation were detected in a dose-dependent manner after taurine treatment in NPC cells. In conclusion, taurine may play an anti-tumor role by activating tumor suppressor PTEN and p53.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/patologia , Taurina/farmacologia , Linhagem Celular Tumoral , China , Humanos , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico , PTEN Fosfo-Hidrolase/metabolismo , Proteína Supressora de Tumor p53/metabolismo
6.
Chem Biol Interact ; 312: 108799, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31433961

RESUMO

Black seed (Nigella sativa) oil has been used in various dermatological applications, and its major constituent, thymoquinone (TQ) has been shown to exhibit antiproliferative activity against various cancer cells. In this study, we tried to provide a mechanistic basis of apoptosis induced by TQ. Skin squamous carcinoma A431 cells were treated with TQ to monitor the apoptosis induced by TQ. Western blot analysis was performed to detect expression of apoptotic or anti-apoptotic proteins. Cell viability and apoptosis were measured by using the MTT test and FACS analysis, respectively. The induction of intracellular reactive oxygen species (ROS) by TQ was evaluated by 2',7'-dichlorofluorescein diacetate staining. In vivo xenograft study was followed to confirm the antiproliferative effect of TQ. Treatment of A431 cells with TQ-induced apoptosis, which was associated with the induction of p53 and Bax, inhibition of Mdm2, Bcl-2, and Bcl-xl expression, and activation of caspase-9, -7, and -3. TQ inhibited the constitutive phosphorylation and DNA binding activity of signal transducer and activator of transcription-3 (STAT3) in A431 cells by blocking the phosphorylation of the upstream kinase, Src. Moreover, the expression of STAT3 target gene products, cyclin D1 and survivin, was attenuated by TQ treatment. The generation of ROS was increased during TQ-induced apoptosis, and the pretreatment of N-acetyl cysteine, a ROS scavenger, reversed the apoptotic effect of TQ. In vivo study with NOD scid gamma (NSG) mice confirmed the inhibitory effect of TQ on the growth of A431 cells. Our results provide the first demonstration that TQ induces the apoptosis of A431 cells through generation of ROS and inhibition of STAT3 signaling.


Assuntos
Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Benzoquinonas/farmacologia , Regulação para Baixo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT3/metabolismo , Animais , Antineoplásicos/uso terapêutico , Benzoquinonas/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Endogâmicos NOD , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transplante Heterólogo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
7.
J Agric Food Chem ; 67(34): 9477-9491, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31429552

RESUMO

Lipopolysaccharide (LPS) is a bacterial endotoxin that induces intestine inflammation. Milk exosomes improve the intestine and immune system development of newborns. This study aims to establish the protective mechanisms of porcine milk exosomes on the attenuation of LPS-induced intestinal inflammation and apoptosis. In vivo, exosomes prevented LPS-induced intestine damage and inhibited (p < 0.05) LPS-induced inflammation. In vitro, exosomes inhibited (p < 0.05) LPS-induced intestinal epithelial cells apoptosis (23% ± 0.4% to 12% ± 0.2%). Porcine milk exosomes also decreased (p < 0.05) the LPS-induced TLR4/NF-κB signaling pathway activation. Furthermore, exosome miR-4334 and miR-219 reduced (p < 0.05) LPS-induced inflammation through the NF-κB pathway and miR-338 inhibited (p < 0.05) the LPS-induced apoptosis via the p53 pathway. Cotransfection with these three miRNAs more effectively prevented (p < 0.05) LPS-induced cell apoptosis than these miRNAs individual transfection. The apoptosis percentage in the group cotransfected with the three miRNAs (14% ± 0.4%) was lower (p < 0.05) than that in the NC miRNA group (28% ± 0.5%), and also lower than that in each individual miRNA group. In conclusion, porcine milk exosomes protect the intestine epithelial cells against LPS-induced injury by inhibiting cell inflammation and protecting against apoptosis through the action of exosome miRNAs. The presented results suggest that the physiological amounts of miRNAs-enriched exosomes addition to infant formula could be used as a novel preventative measure for necrotizing enterocolitis.


Assuntos
Apoptose , Células Epiteliais/citologia , Exossomos/metabolismo , MicroRNAs/metabolismo , Leite/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular , Células Epiteliais/metabolismo , Exossomos/genética , Mucosa Intestinal/citologia , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/efeitos adversos , Masculino , Camundongos , MicroRNAs/genética , NF-kappa B/genética , Transdução de Sinais , Suínos , Receptor 4 Toll-Like/genética , Proteína Supressora de Tumor p53/genética
8.
Life Sci ; 232: 116611, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31260683

RESUMO

PURPOSE: To observe the effect of dexmedetomidine (DEX) on mitochondrial apoptosis of hippocampal neurons in hypoxia/reoxygenation (H/R) brain injury in developing rats, and to investigate its regulatory mechanism on HIF-1α/p53 signaling pathway. METHODS: Hypoxia/reoxygenation model was used in this study. TUNEL assay was performed to detect cell apoptosis. Immunohistochemical analysis and Western-blotting analysis were conducted to detect Cytochrome-C (Cyt-c), APAF-1, Caspase-3, Neuroglobin (Ngb), HIF-1α and p53 expression. After 28 days, Morris water maze (MWM) was performed. RESULTS: 50 µg/kg DEX improved H/R-induced brain injury and inhibited mitochondrial apoptosis in rats. Western-blotting and Immunohistochemical results demonstrated that DEX could up-regulate Ngb through α2 receptor to inhibit H/R-induced mitochondrial apoptosis. In addition, by adding inhibitors yohimbine and 2-methoxyestradiol (2ME2), we found that DEX could activate HIF-1α/p53 signaling pathway. MWM test showed that DEX could enhance long-term learning and memory of H/R brain injury rats. CONCLUSION: DEX alleviates H/R-induced brain injury and mitochondrial apoptosis in developing rats through α2 receptor, which may be related to activation of HIF-1α/p53 signaling pathway to up-regulate the expression of Ngb.


Assuntos
Hipóxia Celular/efeitos dos fármacos , Dexmedetomidina/farmacologia , Hipocampo/efeitos dos fármacos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neurônios/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Hipocampo/metabolismo , Hipocampo/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Masculino , Mitocôndrias/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/efeitos dos fármacos
9.
Life Sci ; 232: 116677, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31340166

RESUMO

AIMS: Senescence is a state ensuing aging to eliminate age-associated damage with an irreversible cell-cycle arrest mechanism, which is historically believed to be one of the tumor responses to therapy. Doxorubicin as an anti-cancer drug has been used in cancer treatment for a long time. Liposomal doxorubicin (Ldox) is a liposomal formulation of doxorubicin, which increases the doxorubicin permanency. The aim of this study was to examine the toxicity of these two formulations by comparing them in terms of their ability to induce cellular senescence. MAIN METHODS: The study groups included a control group, three DOX (0.75, 0.5, 0.1 mg/kg/BW) and three Ldox groups (0.1, 0.05, 0.025 mg/kg/BW). Heart tissues were studied regarding oxidative stress assessment, mitochondrial function, inflammatory markers and biochemical and histopathological evaluation. Real-Time PCR was used for P53 and SA ß-gal expression. KEY FINDINGS: Based on the results, the highest doses of Dox and Ldox (0.75 and 0.1 mg/kg/BW respectively) significantly increased the level of inflammatory markers and according to other factors especially p53 and SA ß-gal expression, both were able to induce senescence but the changes in Ldox were less tangible than the Dox.


Assuntos
Senescência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , NF-kappa B/metabolismo , Animais , Biomarcadores/metabolismo , Doxorrubicina/análogos & derivados , Glutationa Peroxidase/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Miocárdio/patologia , Estresse Oxidativo/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Proteína Supressora de Tumor p53/metabolismo
10.
Gene ; 712: 143963, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31279706

RESUMO

BACKGROUND: The aim of this study was to identify the expression of LIM and calponin-homology domains 1 (LIMCH1) in lung cancer and normal tissues, to determine the interaction between LIMCH1 and HUWE1 in regulating p53 stability. METHODS: The expression of LIMCH1 was detected by the Oncomine and Cancer Genome Atlas databases. Expression of LIMCH1 mRNA was identified using qRT-PCR. In transfected human lung cancer cells, co-immunoprecipitation experiments were performed. The mechanism that HUWE1 sustained lung cancer malignancy was verified by western blotting. The proliferation of tranfected cells was assessed by CCK-8 assay and colony formation. RESULTS: Bioinformatic data and e TCGA database suggested LIMCH1 mRNA levels in tumor tissues were down-regulated compared to tumor adjacent tissues. We found low expression of LIMCH1 mRNA in tumor sites and tumor cell line. Exogenous expression of LIMCH1 interacts with HUWE1 promotes expression of p53. Use of siRNA or shRNA against LIMCH1 resulted in decreased p53 protein levels. LIMCH1 deletion lead to enhance of p53 ubiquitination and protein expression of p53 and substrate p21, puma. Growth curve showed that LIMCH1 deletion significantly promoted the proliferation of A549 cells. CONCLUSIONS: LIMCH1 was a negative regulator and indicated a new molecular mechanism for the pathogenesis of lung cancer via modulating HUWE1 and p53.


Assuntos
Regulação Neoplásica da Expressão Gênica , Proteínas com Domínio LIM/metabolismo , Neoplasias Pulmonares/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Células A549 , Idoso , Linhagem Celular Tumoral , Proliferação de Células , Biologia Computacional , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Proteínas com Domínio LIM/genética , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Processamento de Proteína Pós-Traducional , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
11.
Arkh Patol ; 81(3): 12-18, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31317926

RESUMO

OBJECTIVE: To identify the expression of the molecular markers p53 and p16INK4A in head and neck squamous cell carcinoma (HNSCC) and to assess their impact on its clinical and morphological characteristics and overall survival (OS) rates in patients with HNSCC. MATERIAL AND METHODS: Histological blocks were immunohistochemically studied using anti-p16 and p53 monoclonal antibodies in Krasnodar Clinical Oncology Dispensary One in 2011 to 2016. Overexpression of p16INK4A was established in the presence of 3 and 4 staining points (nuclear and/or cytoplasmic staining in 40% or more tumor cells). That of p53 was determined in the presence of nuclear staining (3+) in more than 50% of tumor cells. RESULTS: Overexpression of p16 was found in 15 (27%) patients (9 (60%) men and 6 (40%) women). The p16-positive tumor status was associated with the female sex (p=0.023), which was characteristic of tonsil cancer (p<0.001) and represented by the nonkeratinizing type (p=0.008). Overexpression of p16 was associated with more frequent regional lymph node metastases (p=0.029). Overexpression of p53 was related to G2 tumor (p=0.021) and expression of p53 was less than 50% associated with tongue body cancer (p=0.004). Kaplan-Meier analysis showed that the 3-year OS in p16-positive HNSCC patients was significantly higher than that in p16-negative ones (p=0.048). Significantly higher OS rates were observed in p16-positive HNSCC patients than in p16INK4A-negative ones for Stage III-IV (p=0.021). OS rates in HNSCC patients with co-expression of p16INK4A (3 and 4 points) and p53 (3+) were significantly higher than in the absence of a combination of these molecular markers (p=0.049). At the same time, OS in HNSCC patients with co-expression of p16INK4A (3 and 4 points), p53 (3+) was significantly higher than in the absence of a set of these molecular markers for stage III-IV (p=0.01). OS in patients with Stages I-II HNNSCC and co-expression of p16INK4A (3 and 4 points) and p53 (3+) did not significantly differ from that in the absence of a set of these molecular markers (p=0.960). CONCLUSION: Overexpression of p16INK4A (3 and 4 points) can be used as a prognostic marker to divide patients into subgroups with different clinical and morphological characteristics. The data on the correlation of p53 overexpression as a marker of mutations in the TP53 gene are contradictory and the study has not revealed the worst overall survival rates. A set of markers for the expression of p16 (≥40%) and p53 (≥50%) has been proposed for use as a favorable prognostic sign.


Assuntos
Biomarcadores Tumorais , Carcinoma de Células Escamosas , Inibidor p16 de Quinase Dependente de Ciclina , Genes p53 , Neoplasias de Cabeça e Pescoço , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Células Epiteliais , Feminino , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Prognóstico , Proteína Supressora de Tumor p53/metabolismo
12.
Oncol Rep ; 42(4): 1487-1496, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31322272

RESUMO

Fibrolamellar hepatocellular carcinoma (FL­HCC) is a variant of hepatocellular carcinoma (HCC) that most commonly affects adolescents and young adults and is associated with an extremely poor prognosis due to the lack of effective chemotherapeutic agents. Mutations in p53 are a common oncogenic driver in HCC but not in FL­HCC. However, in tumors lacking a p53 mutation, the tumor suppressor activity of p53 has been revealed to be dysregulated in several different cancer types. One mechanism has been attributed to the overexpression of mouse double minute 4 protein (MDM4), a negative regulator of p53, which inhibits the normal functions of p53 including induction of apoptosis and DNA repair. Therefore, restoring the normal function of p53 in cancer cells by targeting MDM4 has become a potential therapeutic strategy. Hence, in the present study the components of the DNA damage response (DDR) pathway were examined; ATM, p53, and MDM4 in FL­HCC. Seven FL­HCC tumors along with their adjacent non­neoplastic hepatic tissues were examined. Ataxia­telangiectasia mutated (ATM), p53, and MDM4 protein expression was assessed using western blot analysis and cellular localization was determined using immunohistochemistry (IHC). MDM4 mRNA transcript levels were assessed using RT­qPCR. The present results demonstrated that the DNA damage sensor, ATM, is phosphorylated and localized to the nuclei of tumor cells. While there was a significant increase in total p53 protein in tumor cells, phosphorylated p53 was revealed to preferably localize to the cytoplasmic compartment of tumor cells. Notably, the present results revealed that MDM4 transcript levels were increased in the majority of tumor samples and the nuclear MDM4 levels were significantly increased in tumor tissue compared to their adjacent non­neoplastic liver tissue. The present results indicated that increased MDM4 expression and nuclear localization may be a potential mechanism for p53 dysregulation in FL­HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Nucleares/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Adolescente , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Criança , Feminino , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteína Supressora de Tumor p53/metabolismo
13.
Cell Physiol Biochem ; 53(2): 301-322, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31343125

RESUMO

BACKGROUND/AIMS: Propolis is one of the most promising natural products, exhibiting not only therapeutic but also prophylactic actions. Propolis has several biological and pharmacological properties, including hepatoprotective activities. The present study aimed to investigate the underlying molecular mechanisms of propolis against CCl4-mediated liver fibrosis. METHODS: Three groups of male BALB/c mice (n=15/ group) were used: group 1 comprised control mice; groups 2 and 3 were injected with CCl4 for the induction of liver fibrosis. Group 3 was then orally supplemented with propolis (100 mg/kg body weight) for four weeks. Different techniques were used to monitor the antifibrotic effects of propolis, including histopathological investigations using H&E, Masson's trichrome and Sirius red staining; Western blotting; flow cytometry; and ELISA. RESULTS: We found that the induction of liver fibrosis by CCl4 was associated with a significant increase in hepatic collagen and α-smooth muscle actin (α-SMA) expression. Moreover, CCl4-treated mice also exhibited histopathological alterations in the liver architecture. Additionally, the liver of CCl4-treated mice exhibited a marked increase in proinflammatory signals, such as increased expression of HSP70 and increased levels of proinflammatory cytokines and ROS. Mechanistically, the liver of CCl4-treated mice exhibited a significant increase in the phosphorylation of AKT and mTOR; upregulation of the expression of BAX and cytochrome C; downregulation of the expression of Bcl2; a significant elevation in the levels of TGF-ß followed by increased phosphorylation of SMAD2; and a marked increase in the expression of P53 and iNOS. Interestingly, oral supplementation of CCl4-treated mice with propolis significantly abolished hepatic collagen deposition, abrogated inflammatory signals and oxidative stress, restored CCl4-mediated alterations in the signaling cascades, and hence repaired the hepatic architecture nearly to the normal architecture observed in the control mice. CONCLUSION: Our findings revealed the therapeutic potential and the underlying mechanisms of propolis against liver fibrosis.


Assuntos
Apoptose/efeitos dos fármacos , Cirrose Hepática Experimental/patologia , Própole/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Tetracloreto de Carbono/toxicidade , Citocinas/metabolismo , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Óxido Nítrico Sintase Tipo II/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteína Smad2/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
14.
Anticancer Res ; 39(7): 3353-3363, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31262856

RESUMO

Vitamin D, or more precisely its active metabolite calcitriol (1,25-(OH)2D3), plays a fundamental role in bone metabolism and differentiation as well as in intestinal absorption of calcium and regulation of calcium-phosphate metabolism. Recent decades have brought about the discovery of the role of calcitriol in processes regulating cell differentiation, proliferation, angiogenesis and apoptosis. This creates the potential for numerous therapeutic applications of vitamin D in diseases associated with autoaggressive immune responses or in cancer. This study presents selected issues regarding current knowledge of the anti-cancer mechanisms of vitamin D.


Assuntos
Neoplasias , Vitamina D/fisiologia , Vitaminas/fisiologia , Animais , Apoptose , Ciclo Celular , Proteínas Hedgehog/metabolismo , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Neovascularização Patológica , Receptores de Calcitriol/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta/efeitos adversos
15.
Nat Commun ; 10(1): 2588, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197172

RESUMO

The brain is a genomic mosaic shaped by cellular responses to genome damage. Here, we manipulate somatic genome stability by conditional Knl1 deletion from embryonic mouse brain. KNL1 mutations cause microcephaly and KNL1 mediates the spindle assembly checkpoint, a safeguard against chromosome missegregation and aneuploidy. We find that following Knl1 deletion, segregation errors in mitotic neural progenitor cells give rise to DNA damage on the missegregated chromosomes. This triggers rapid p53 activation and robust apoptotic and microglial phagocytic responses that extensively eliminate cells with somatic genome damage, thus causing microcephaly. By leaving only karyotypically normal progenitors to continue dividing, these mechanisms provide a second safeguard against brain somatic aneuploidy. Without Knl1 or p53-dependent safeguards, genome-damaged cells are not cleared, alleviating microcephaly, but paradoxically leading to total pre-weaning lethality. Thus, mitotic genome damage activates robust responses to eliminate somatic mutant cells, which if left unpurged, can impact brain and organismal fitness.


Assuntos
Aneuploidia , Microcefalia/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Neurais/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/genética , Segregação de Cromossomos/genética , Dano ao DNA/genética , Modelos Animais de Doenças , Embrião de Mamíferos , Instabilidade Genômica , Humanos , Cinetocoros/metabolismo , Camundongos , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/genética , Cultura Primária de Células , Deleção de Sequência , Fuso Acromático/metabolismo
16.
J Sci Food Agric ; 99(13): 6097-6107, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31250448

RESUMO

BACKGROUND: Reactive oxygen species (ROS) can cause DNA damage. Rice protein (RP) inhibits ROS accumulation. However, a link between the reduction of ROS-derived DNA damage and the intake of RP is far from clear. The main objective of this study is to elucidate the effects of RPs on the reduction of DNA damage in growing and adult rats. RESULTS: An intake of RP for 2 weeks significantly reduced the hepatic accumulation of ROS and 8-hydroxydeoxyguanosine (8-OHdG) in growing and adult rats, whereas the hepatic p53 content was markedly increased by RPs. After 2 weeks' feeding, the mRNA levels and protein expressions of p53, ataxia-telangiectasia mutated (ATM), and Checkpoint kinase 2 (Chk2) were up-regulated by RPs, whereas Murine Double Minute 2 (MDM2) expressions were markedly inhibited by RPs, resulting in more p53 being translocated into the nucleus. Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) was activated by RP by reducing Kelch-like ECH-associated protein 1 (Keap1), resulting in the up-regulation of antioxidant expressions of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in RP groups. CONCLUSION: Rice protein can exert an endogenous antioxidant activity to reduce ROS-derived DNA damage by activating the Nrf2-Keap1 pathway. This study suggests that the activation of the ATM-Chk2-p53 pathway might be one of the mechanisms exerted by RP for reducing DNA damage in growing and adult rats. © 2019 Society of Chemical Industry.


Assuntos
Antioxidantes/metabolismo , Dano ao DNA , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Catalase/genética , Catalase/metabolismo , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fígado/metabolismo , Masculino , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Proteína Supressora de Tumor p53/genética
17.
Gene ; 711: 143939, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31220581

RESUMO

Sirtuin 1 is one of the regulators of cell growth and survival and its inhibition is suggested as a suitable mechanism to overcome breast cancer development. In this study we explored the role of miR-211-5p in SIRT1/p53 pathway and its influence on breast cancer cell viability and apoptosis. Cells were transfected with miR-211-5p mimic and inhibitor to modulate cellular miR-211-5p levels in breast cancer cell lines, MDA-MB-231 and MCF-7. Gene expression of miR-211-5p and SIRT1 were measured with real-time PCR. SIRT1 protein level and the acetylation of p53 as well as SIRT1 activity were evaluated by Western blotting and fluorometry, respectively. In order to explore the direct attachment of miR-211-5p to the 3'-UTR of SIRT1 mRNA, luciferase reporter assay was applied. Cell viability in response to miR-211-5p was studied by MTT assay and apoptosis was assessed by annexin V labeling followed by flow cytometry. Results showed that SIRT1 gene and protein expression were inhibited by miR-211-5p and the 3'-UTR of SIRT1 was found to be directly targeted by miR-211-5p. Inhibition of SIRT1 expression resulted in its reduced activity. Up-regulation of miR-211-5p was also followed by a significant decline in the acetylation status of p53 which was associated with remarkable decreased cell viability and induction of apoptosis in breast cancer cells. Antisense oligonucleotide of miR-211-5p acted as its inhibitor and exerted opposite effects both on SIRT1 expression and cell apoptosis. In conclusion, inhibition of SIRT1 by miR-211-5p could effectively reduce breast cancer cell survival and cause cell death and therefore might be considered a seemly mechanism for designing anticancer therapies.


Assuntos
Neoplasias da Mama/metabolismo , MicroRNAs/genética , Sirtuína 1/genética , Sirtuína 1/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Regiões 3' não Traduzidas , Acetilação , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7
18.
Food Chem Toxicol ; 131: 110533, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150783

RESUMO

Hepatocellular carcinoma is the fifth most common and the third most lethal cancer worldwide. In recent years, natural flavonoids have drawn great attention as repository for the exploitation of novel antineoplastic agents. 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC), a functional chalcone isolated from the buds of Cleistocalyx operculatus, has been reported to exert potent cytotoxicity against multi-drug resistant BEL-7402/5-FU cells. In this study, the precise mechanisms of DMC-mediated growth inhibition in BEL-7402/5-FU cells were further investigated. DMC was found to trigger apoptosis predominantly via the mitochondria-dependent pathway and the enhancement of reactive oxygen species (ROS) generation. Meanwhile, DMC induced G1 cell cycle arrest through downregulation of cyclin D1 and CDK4. Furthermore, DMC increased p53 level and inhibited NF-κB nuclear-localization via suppression of PI3K/AKT signaling axis, which might be the underlying mechanism of DMC-induced apoptosis and cell cycle arrest in BEL-7402/5-FU cells. Collectively, the study elucidated the mechanisms by which DMC may inhibit the growth of BEL-7402/5-FU cells and suggested the possibility that DMC might be a promising candidate therapeutic agent for hepatoma treatment in the future.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Chalconas/farmacologia , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Flores/química , Humanos , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Syzygium/química , Proteína Supressora de Tumor p53/metabolismo
19.
Planta Med ; 85(9-10): 755-765, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31185503

RESUMO

Antcin-A (ATA) is a steroid-like phytochemical isolated from the fruiting bodies of a precious edible mushroom Antrodia cinnamomea. We previously showed that ATA has strong anti-inflammatory and anti-tumor effects; however, other possible bioactivities of this unique compound remain unexplored. In the present study, we aimed to investigate the modulation of epithelial-to-mesenchymal transition (EMT), anti-migration, and anti-invasive potential of ATA against human breast cancer cells in vitro. Human breast cancer cell lines, MCF-7 and MDA-MB-231, were incubated with ATA for 24 h. Wound healing, trans-well invasion, western blot, q-PCR, F-actin staining, and immunofluorescence assays were performed. We found that treatment with ATA significantly blocked EMT processes, as evidenced by upregulation of epithelial markers (E-cadherin and occludin) and downregulation of mesenchymal markers (N-cadherin and vimentin) via suppression of their transcriptional repressor ZEB1. Next, we found that ATA could induce miR-200c, which is a known player of ZEB1 repression. Further investigations revealed that ATA-mediated induction of miR-200c is associated with transcriptional activation of p53, as confirmed by the fact that ATA failed to induce miR-200c or suppress ZEB1 activity in p53 inhibited cells. Further in vitro wound healing and trans-well invasion assays support that ATA could inhibit migratory and invasive potentials of breast cancer cells, and the effect was likely associated with induced phenotypic modulation. Taken together, the present study suggests that antcin-A could be a lead phyto-agent for the development of anti-metastatic drug for breast cancer treatment.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Esteroides/farmacologia , Proteína Supressora de Tumor p53/genética , Antígenos CD/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Caderinas/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , MicroRNAs/genética , Fator de Crescimento Transformador beta1/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
20.
Anticancer Res ; 39(6): 2767-2775, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31177112

RESUMO

BACKGROUND/AIM: Colorectal adenoma is well known as a precursor lesion of colorectal adenocarcinoma (ADC). We recently reported the significance of CD204 (+) tumor-associated macrophages (TAMs), a vital component of the tumor microenvironment, in the carcinoma development of gastric adenoma. The aim of the present study was to clarify the roles of TAM in the malignant transformation of colorectal adenoma. MATERIALS AND METHODS: We immunohistochemically assessed the TAM number in 88 tubular or tubulovillous adenomas that were classified into L (low-grade adenomas) or H (high-grade adenomas). RESULTS: Larger adenoma size, higher frequency of villous structure, loss of proliferation polarity, p53 expression, larger TAM numbers and larger microvessel density (MVD) were detected in Group H than in Group L adenomas. Positive relations were observed between TAM and MVD, proliferation polarity and the expression of p53. CONCLUSION: CD204 (+) TAM is a novel component in the malignant transformation of colorectal adenoma.


Assuntos
Adenoma/patologia , Neoplasias Colorretais/patologia , Macrófagos/metabolismo , Receptores Depuradores Classe A/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Adenoma/metabolismo , Idoso , Idoso de 80 Anos ou mais , Polaridade Celular , Proliferação de Células , Neoplasias Colorretais/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Carga Tumoral , Microambiente Tumoral , Regulação para Cima
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