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1.
J Nanosci Nanotechnol ; 20(2): 659-667, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383060

RESUMO

As a new kind of two-dimensional nanomaterial, black phosphorus (BP) nanosheets have attracted significant interests in diverse bioapplications due to their unique structure and physicochemical properties. Despite BP nanosheets' advantages in cancer diagnosis and therapy applications, their biosafety issues are still unclear. Herein, we report a systematic study on the In Vitro and In Vivo toxicity of BP nanosheets. In Vitro experiments showed that BP nanosheets decrease the viability of human bronchial epithelial cells in a time- and dose-dependent manner. The mechanism study showed that BP nanosheets interfere with mitochondrial membrane potential, leading to an increase in intracellular ROS. These responses further initiated the activation of the caspase-3 and ultimately dictated cells to undergo apoptosis. Then, the In Vivo experiments of BP nanosheets revealed that single injection of BP nanosheets does not cause toxicity to mice in a short period of time, whereas multiple injections of BP nanosheets exert adverse effects on liver and renal function of mice. Interestingly, the liver and renal function of the mice returned to normal after a recovery period. Our findings provide insights into the rational design of BP nanosheets and guide their applications in biomedical fields.

2.
Mol Med Rep ; 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31432163

RESUMO

The E3 ubiquitin ligase RAD18 has been identified as an oncoprotein that exhibits prometastatic properties in various types of cancer; however, the role of RAD18 in cervical cancer (CC) remains unclear. In the present study, it was revealed that increased expression of RAD18 was associated with worse prognosis of patients with CC. Knockdown of endogenous RAD18 suppressed the motility and invasiveness of CC cells, as evaluated by Transwell assays. mRNA sequencing revealed that silencing RAD18 altered the expression profile of proinflammatory mediators, such as interleukin­1ß (IL­1ß). Furthermore, exogenous IL­1ß treatment rescued RAD18­mediated CC cell invasion. These findings indicated an underlying mechanism via which RAD18 promotes CC progression, suggesting that RAD18 may be a potential biomarker and therapeutic target for malignant CC.

3.
Cancer Sci ; 109(12): 3783-3793, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30281878

RESUMO

The p53-inducible gene 3 (PIG3) is one of the p53-induced genes at the onset of apoptosis, which plays an important role in cell apoptosis and DNA damage response. Our previous study reported an oncogenic role of PIG3 associated with tumor progression and metastasis in non-small cell lung cancer (NSCLC). In this study, we further analyzed PIG3 mRNA expression in 504 lung adenocarcinoma (LUAD) and 501 lung squamous cell carcinoma (LUSC) tissues from The Cancer Genome Atlas database and we found that PIG3 expression was significantly higher in LUAD with lymph node metastasis than those without, while no difference was observed between samples with and without lymph node metastasis in LUSC. Gain and loss of function experiments were performed to confirm the metastatic role of PIG3 in vitro and to explore the mechanism involved in its oncogenic role in NSCLC metastasis. The results showed that PIG3 knockdown significantly inhibited the migration and invasion ability of NSCLC cells, and decreased paxillin, phospho-focal adhesion kinase (FAK) and phospho-Src kinase expression, while its overexpression resulted in the opposite effects. Blocking FAK with its inhibitor reverses PIG3 overexpression-induced cell motility in NSCLC cells, indicating that PIG3 increased cell metastasis through the FAK/Src/paxillin pathway. Furthermore, PIG3 silencing sensitized NSCLC cells to FAK inhibitor. In conclusion, our data revealed a role for PIG3 in inducing LUAD metastasis, and its role as a new FAK regulator, suggesting that it could be considered as a novel prognostic biomarker or therapeutic target in the treatment of LUAD metastasis.

4.
Gastroenterol Res Pract ; 2018: 2968252, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29743885

RESUMO

DAB2IP (DOC2/DAB2 interactive protein) is downregulated in several cancer types, and its downregulation is involved in tumor cell proliferation, apoptosis, metastasis, and epithelial-mesenchymal transition (EMT). We aimed to investigate the potential role of DAB2IP in the development and progression of gastric cancer. DAB2IP levels were analyzed in human gastric cancer and adjacent normal tissues by Western blots and immunohistochemistry. Potential roles of DAB2IP in regulating gastric cancer cell growth and metastasis were examined by genetic manipulation in vitro. The molecular signaling was determined to understand the mechanisms of observed DAB2IP effects. DAB2IP level is lower in gastric cancer tissues as compared to paired normal tissues. Knockdown of DAB2IP enhanced gastric cancer cell growth and metastasis in vitro and promoted EMT progress at both protein and mRNA levels. Silencing DAB2IP activated extracellular signal-regulated kinase 1/2 (ERK1/2) pathway, and the enhanced proliferation and migration ability induced by DAB2IP knockdown were reduced after incubation with U0126 in SGC7901 gastric cancer cells. Inhibition of DAB2IP enhances gastric cancer cell growth and metastasis through targeting the ERK1/2 signaling, indicating that it may serve as a potential target for treatment of gastric cancer.

5.
Toxicol Sci ; 164(1): 339-352, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29669094

RESUMO

Graphene quantum dots (GQDs) have attracted significant interests due to their unique chemical and physical properties. In this study, we investigated the potential effects of hydroxyl-modified GQDs (OH-GQDs) on the human esophageal epithelial cell line HET-1A. Our data revealed significant cytotoxicity of OH-GQDs which decreased the viability of HET-1A in a dose and time-dependent manner. The moderate concentration (25 or 50 µg/ml) of OH-GQDs significantly blocked HET-1A cells in G0/G1 cell cycle phase. An increased percentage of γH2AX-positive and genomically unstable cells were also detected in cells treated with different doses of OH-GQDs (25, 50, and 100 µg/ml). Microarray data revealed that OH-GQDs treatment down-regulated genes related to DNA damage repair, cell cycle regulation and cytoskeleton signal pathways indicating a novel role of OH-GQDs. Consistent with the microarray data, OH-GQDs disrupted microtubule structure and inhibited microtubule regrowth around centrosomes in HET-1A cells. In conclusion, our findings provide important evidence for considering the application of OH-GQDs in biomedical fields.

6.
Toxicol Appl Pharmacol ; 348: 76-84, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29679654

RESUMO

Esophageal squamous cell carcinoma (ESCC) is the most common form of esophageal cancer in China. Since chemotherapy is the standard clinical intervention for advanced ESCC, the development of highly effective and minimal/non-toxic drugs is essential to improve the clinical outcome and prognosis of the patients. A novel derivative of vanillin, 6-bromine-5-hydroxy-4-methoxybenzaldehyde (BVAN08), has been recently reported to activate different cell death pathways in cancer cells. In this study, we demonstrate that BVAN08 exhibits a potent anti-proliferation effect on ESCC cells (TE-1 and ECA-109) by inhibiting the expression of PLK1, an important mitotic kinase. Consistent with this, BVAN08 induces mitotic arrest and chromosomal misalignment in ESCC cells. The disruption of microtubule nucleation around centrosomes is also observed in BVAN08 treated ESCC cells. Furthermore, BVAN08 enhances radio-sensitivity of ESCC cells by prolonging DNA damage repair. These findings underscore the potential value of BVAN08 in cancer therapeutics and demonstrate the underlying mechanism by which BVAN08 induces mitotic catastrophe and enhances radio-sensitivity in ESCC cells.


Assuntos
Antineoplásicos/farmacologia , Benzaldeídos/farmacologia , Carcinoma de Células Escamosas/terapia , Proteínas de Ciclo Celular/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Quimiorradioterapia , Neoplasias Esofágicas/terapia , Mitose/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Tolerância a Radiação/efeitos dos fármacos , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/patologia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Centrossomo/efeitos dos fármacos , Centrossomo/patologia , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Neoplasias Esofágicas/enzimologia , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago , Humanos , Microtúbulos/efeitos dos fármacos , Microtúbulos/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
7.
Nucleic Acids Res ; 46(4): 1847-1859, 2018 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-29309644

RESUMO

The DNA-dependent protein kinase (DNA-PK), consisting of the DNA binding Ku70/80 heterodimer and the catalytic subunit DNA-PKcs, has been well characterized in the non-homologous end-joining mechanism for DNA double strand break (DSB) repair and radiation resistance. Besides playing a role in DSB repair, DNA-PKcs is required for the cellular response to replication stress and participates in the ATR-Chk1 signaling pathway. However, the mechanism through which DNA-PKcs is recruited to stalled replication forks is still unclear. Here, we report that the apoptosis mediator p53-induced protein with a death domain (PIDD) is required to promote DNA-PKcs activity in response to replication stress. PIDD is known to interact with PCNA upon UV-induced replication stress. Our results demonstrate that PIDD is required to recruit DNA-PKcs to stalled replication forks through direct binding to DNA-PKcs at the N' terminal region. Disruption of the interaction between DNA-PKcs and PIDD not only compromises the ATR association and regulation of DNA-PKcs, but also the ATR signaling pathway, intra-S-phase checkpoint and cellular resistance to replication stress. Taken together, our results indicate that PIDD, but not the Ku heterodimer, mediates the DNA-PKcs activity at stalled replication forks and facilitates the ATR signaling pathway in the cellular response to replication stress.

8.
Cancer Sci ; 108(12): 2503-2510, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28905458

RESUMO

An aberrantly elevated expression of DNA polymerase ι (Pol ι) is significantly associated with poor prognosis of patients with esophageal squamous cell carcinoma (ESCC), yet the mechanisms behind this phenomenon remain obscure. Based on the RNA-Seq transcriptome and real-time PCR analysis, we identified ETS-1 as a candidate gene involved in Pol ι-mediated progression of ESCC. Wound-healing and transwell assay indicated that downregulation of ETS-1 attenuates Pol ι-mediated invasiveness of ESCC. Signaling pathway analysis showed that Pol ι enhances ETS-1 phosphorylation at threonine-38 through the Erk signaling pathway in ESCC cells. Kaplan-Meier analysis, based on 93 clinical tissue samples, revealed that ETS-1 phosphorylation at threonine-38 is associated with poor prognosis of ESCC patients. The present study thus demonstrates that phosphorylation of ETS-1 is a critical event in the Pol ι-induced invasion and metastasis of ESCC.


Assuntos
Carcinoma de Células Escamosas/patologia , DNA Polimerase Dirigida por DNA/metabolismo , Neoplasias Esofágicas/patologia , Proteína Proto-Oncogênica c-ets-1/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Movimento Celular , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/mortalidade , Carcinoma de Células Escamosas do Esôfago , Humanos , Estimativa de Kaplan-Meier , Invasividade Neoplásica/patologia , Fosforilação
9.
Biomed Pharmacother ; 94: 843-849, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28802238

RESUMO

Increasing research has indicated that absent in melanoma 2 (AIM2) is aberrantly expressed in several tumor types. However, the association between AIM2 expression and clinicopathological factors or prognosis of patient with colorectal cancer (CRC) remains elusive. In the present study, we first examined the protein and mRNA expression of AIM2 in CRC cell lines by western blotting and quantitative RT-PCR (qRT-PCR). Then, we detected AIM2 expression in CRC tissue using western blotting and immunohistochemistry (IHC) respectively to evaluate its clinicopathological characteristics and prognosis in CRC. Our cytological experiments showed that there was low AIM2 expression in most of the CRC cell lines. Western blotting and IHC indicated that AIM2 expression was obviously lower in the primary CRC tissue than the adjacent normal tissue (P<0.01 and P<0.001). Clinicopathological analysis revealed that low AIM2 expression was significantly associated with some clinicopathological features such as depth of invasion (P=0.020), TNM clinical stage (P=0.013) and lymph node metastasis (P=0.026). Spearman analysis indicated that there was a negative correlation between AIM2 expression and preoperative serum carcino-embryonic antigen (CEA) levels in CRC patients (r=-0.217, P=0.009). Moreover, Kaplan-Meier analysis showed that low expression of AIM2 could lead to a significantly shorter overall survival rate (P=0.001). Cox's proportional hazards model also indicated that the low expression of AIM2 could serve as an independent and significant prognostic factor for survival. Taken together, our findings identify AIM2 as a valuable biomarker for prognosis and a potential therapeutic target for CRC.


Assuntos
Neoplasias Colorretais/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Idoso , Western Blotting , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , RNA Mensageiro/metabolismo , Taxa de Sobrevida
10.
Int J Med Sci ; 14(5): 452-461, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28539821

RESUMO

Objectives: 4E-BP1 is a family member of eIF4E binding proteins (4E-BPs) which act as the suppressors of cap-dependent translation of RNA via competitively associating with cap-bound eIF4E. RNA translation regulation is an important manner to control the cellular responses to a series of stress conditions such as ionizing radiation (IR)-induced DNA damage response and cell cycle controlling. This study aimed to determine the mechanism of 4E-BP1 stabilization and its potential downstream target(s) in the response to IR. Methods: PI3Ks kinase inhibitors were used to determine the signaling control of 4E-BP1 phosphorylation and protein stability. shRNA strategy was employed to silence the expression of 4E-BP1 in HeLa and HepG2 cells, and determine its effect on the irradiation-induced CHK2 phosphorylation. The protein degradation/stability was investigated by western blotting on the condition of blocking novel protein synthesis by cycloheximide (CHX). Results: The phosphorylation of 4E-BP1 at Thr37/46 was significantly increased in both HepG2 and HeLa cells by ionizing radiation. Depression of 4E-BP1 by shRNA strategy resulted in an incomplete G2 arrest at the early stage of 2 hours post-irradiation, as well as a higher accumulation of mitotic cells at 10 and 12 hours post-irradiation as compared to the control cells. Consistently, the CHK2 phosphorylation at Thr68 induced by IR was also attenuated by silencing 4E-BP1 expression. Both PI3K and DNA-PKcs kinase inhibitors significantly decreased the protein level of 4E-BP1, which was associated with the accelerated degradation mediated by ubiquitination-proteasome pathway. Conclusion: PI3K kinase activity is necessary for maintaining 4E-BP1 stability. Our results also suggest 4E-BP1 a novel biological role of regulating cell cycle G2 checkpoint in responding to IR stress in association with controlling CHK2 phosphorylation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Quinase do Ponto de Checagem 2/genética , Fosfatidilinositol 3-Quinases/genética , Fosfoproteínas/genética , Biossíntese de Proteínas/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Células HeLa , Células Hep G2 , Humanos , Fosforilação/efeitos da radiação , Biossíntese de Proteínas/efeitos da radiação , Proteínas Proto-Oncogênicas c-akt/genética , RNA Interferente Pequeno/genética , Radiação Ionizante , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação
11.
J Exp Clin Cancer Res ; 36(1): 39, 2017 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-28259183

RESUMO

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most commonly diagnosed type of lung cancer that is associated with poor prognosis. In this study we explored the potential role of p53-induced gene 3 (PIG3) in the progression of NSCLC. METHODS: Immunohistochemistry was used to determine the expression levels of PIG3 in 201 NSCLC patients. We performed in vitro studies and silenced endogenous PIG3 by using specific siRNAs that specific target PIG3. Immunofluorescent staining was performed to determine the effect of PIG3 on mitotic progression in NSCLC cells. The growth rates of microtubules were determined by microtubule nucleation analysis. Cell proliferation and chemosensitivity were analyzed by CCK8 assays. Annexin V staining and ß-galactosidase activity analysis were used to evaluate PIG3 deficiency-related apoptosis and senescence, respectively. RESULTS: PIG3 expression levels negatively correlated with overall survival and disease-free survival of NSCLC patients. Knock down of PIG3 resulted in repressed proliferation of NSCLC cells and increased aberrant mitosis, which included misaligning and lagging chromosomes, and bi- or multi-nucleated giant cells. In addition, PIG3 contributed to mitotic spindle assembly by promoting microtubule growth. Furthermore, loss of PIG3 sensitized NSCLC cells to docetaxel by enhancing docetaxel-induced apoptosis and senescence. CONCLUSIONS: Our results indicate that PIG3 promotes NSCLC progression and therefore suggest that PIG3 may be a potential prognostic biomarker and novel therapeutic target for the treatment of NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Pulmonares/genética , Mitose , Proteínas Proto-Oncogênicas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Progressão da Doença , Intervalo Livre de Doença , Docetaxel , Feminino , Inativação Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas/genética , Análise de Sobrevida , Taxoides/farmacologia , Adulto Jovem
12.
Oncotarget ; 7(38): 62340-62351, 2016 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-27694690

RESUMO

Radiotherapy is promising and effective for treating prostate cancer but the addition of a tumor cell radiosensitizer would improve therapeutic outcomes. PC-1/PrLZ, a TPD52 protein family member is frequently upregulated in advanced prostate cancer cells and may be a biomarker of aggressive prostate cancer. Therefore, we investigated the potential role of PC-1/PrLZ for increasing radioresistance in human prostate cancer cell lines. Growth curves and survival assays after g-ray irradiation confirmed that depletion of endogenous PC-1/PrLZ significantly increased prostate cancer cell radiosensitivity. Irradiation (IR) increased PC-1/PrLZ expression in a dose- and time-dependent manner and increased radiosensitivity in PC-1/PrLZ-suppressed cells was partially due to decreased DNA double strand break (DBS) repair which was measured with comet and gH2AX foci assays. Furthermore, depletion of PC-1/PrLZ impaired the IR-induced G2/M checkpoint, which has been reported to be correlate with radioresistance in cancer cells. PC-1/PrLZ-deficient cells exhibited higher level of autophagy when compared with control cells. Thus, specific inhibition of PC-1/PrLZ might provide a novel therapeutic strategy for radiosensitizing prostate cancer cells.


Assuntos
Autofagia/efeitos da radiação , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Reparo do DNA/efeitos da radiação , Proteínas de Neoplasias/efeitos da radiação , Neoplasias da Próstata/radioterapia , Tolerância a Radiação , Linhagem Celular Tumoral , Relação Dose-Resposta à Radiação , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Raios gama , Histonas/metabolismo , Histonas/efeitos da radiação , Humanos , Masculino , Microscopia de Fluorescência , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Fosforilação , Próstata/citologia , Próstata/efeitos da radiação , Neoplasias da Próstata/patologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Regulação para Cima
13.
Genes (Basel) ; 7(10)2016 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-27706111

RESUMO

Increasing evidence indicates that elevated expression of enhancer of zeste homolog 2 gene (EZH2) in many human malignant tumors acts a significant role in the oncogenic process. However, the underlying molecular mechanism is still unclarified. It is evident that apoptosis and autophagy of tumor cells is crucial for the tumorigenesis and progression of cancer, however, the exact role of EZH2 plays in apoptosis and autophagy has not been fully elucidated in colorectal cancer (CRC). Our previous study found that the expression level of EZH2 was higher in CRC tumor tissues than in the paired normal tissues using immunohistochemical analysis. We also recently found that the autophagy-related gene-related protein Ambra1 plays an important role in the autophagy pathway in CRC cells. In this study, mRNA and protein expression of EZH2 in four CRC cell lines were tested at first and RKO and HCT116 cells showed the highest levels among them. Here we transfected with EZH2-shRNA, or added DZNep (an EZH2 inhibitor) to RKO and HCT116 cells in order to detect the effect of EZH2 on autophagy via determining the change of the protein expression of LC3 and Ambra1. The outcome indicated an obvious decrease of autophagy level in cells transfected with EZH2-shRNA or DZNep. We also found the apoptotic rate of cells was elevated significantly after downregulation of EZH2. In addition, compared to control group, CRC cells transfected with EZH2-shRNA or added DZNep revealed a significantly increased G1 cell cycle rate and an obvious decrease in the G2 cell cycle rate. Further analysis showed that knockdown of EZH2 induced cell-cycle arrest in CRC cells. Meanwhile, downregulation of EZH2 in CRC cells induces autophagy and apoptosis. Taken together, our results suggest that EZH2 plays a critical role in autophagy and apoptosis in the progression of CRC, which potentially facilitates the development of an ideal strategy for combating colorectal cancer.

14.
Nucleic Acids Res ; 44(18): 8842-8854, 2016 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-27568005

RESUMO

Defects in kinetochore-microtubule (KT-MT) attachment and the spindle assembly checkpoint (SAC) during cell division are strongly associated with chromosomal instability (CIN). CIN has been linked to carcinogenesis, metastasis, poor prognosis and resistance to cancer therapy. We previously reported that the DAB2IP is a tumor suppressor, and that loss of DAB2IP is often detected in advanced prostate cancer (PCa) and is indicative of poor prognosis. Here, we report that the loss of DAB2IP results in impaired KT-MT attachment, compromised SAC and aberrant chromosomal segregation. We discovered that DAB2IP directly interacts with Plk1 and its loss inhibits Plk1 kinase activity, thereby impairing Plk1-mediated BubR1 phosphorylation. Loss of DAB2IP decreases the localization of BubR1 at the kinetochore during mitosis progression. In addition, the reconstitution of DAB2IP enhances the sensitivity of PCa cells to microtubule stabilizing drugs (paclitaxel, docetaxel) and Plk1 inhibitor (BI2536). Our findings demonstrate a novel function of DAB2IP in the maintenance of KT-MT structure and SAC regulation during mitosis which is essential for chromosomal stability.


Assuntos
Pontos de Checagem do Ciclo Celular , Instabilidade Cromossômica , Cinetocoros/metabolismo , Microtúbulos/metabolismo , Fuso Acromático/metabolismo , Proteínas Ativadoras de ras GTPase/metabolismo , Animais , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Aberrações Cromossômicas , Segregação de Cromossomos , Técnicas de Inativação de Genes , Humanos , Camundongos , Mitose/efeitos dos fármacos , Mitose/genética , Fosforilação , Ligação Proteica , Transporte Proteico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/metabolismo , Interferência de RNA , Moduladores de Tubulina/farmacologia , Proteínas Ativadoras de ras GTPase/genética
15.
Sci Rep ; 6: 30165, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27417393

RESUMO

Radiation-induced bystander effect (RIBE) describes a set of biological effects in non-targeted cells that receive bystander signals from the irradiated cells. RIBE brings potential hazards to adjacent normal tissues in radiotherapy, and imparts a higher risk than previously thought. Excessive release of some substances from irradiated cells into extracellular microenvironment has a deleterious effect. For example, cytokines and reactive oxygen species have been confirmed to be involved in RIBE process via extracellular medium or gap junctions. However, RIBE-mediating signals and intercellular communication pathways are incompletely characterized. Here, we first identified a set of differentially expressed miRNAs in the exosomes collected from 2 Gy irradiated human bronchial epithelial BEP2D cells, from which miR-7-5p was found to induce autophagy in recipient cells. This exosome-mediated autophagy was significantly attenuated by miR-7-5p inhibitor. Moreover, our data demonstrated that autophagy induced by exosomal miR-7-5p was associated with EGFR/Akt/mTOR signaling pathway. Together, our results support the involvement of secretive exosomes in propagation of RIBE signals to bystander cells. The exosomes-containing miR-7-5p is a crucial mediator of bystander autophagy.


Assuntos
Autofagia/fisiologia , Brônquios/metabolismo , Efeito Espectador/fisiologia , Células Epiteliais/metabolismo , Exossomos/metabolismo , MicroRNAs/metabolismo , Linhagem Celular , Humanos , Radiação Ionizante , Transdução de Sinais/fisiologia
16.
Oncotarget ; 7(22): 32274-85, 2016 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-27057634

RESUMO

DNA polymerase iota (Pol ι) is an error-prone DNA polymerase involved in translesion DNA synthesis (TLS) that contributes to the accumulation of DNA mutations. We recently showed that Pol ι is overexpressed in human esophageal squamous cell cancer (ESCC) tissues which promotes ESCC' progression. The present study was aimed at investigating the molecular mechanisms by which Pol ι enhances the invasiveness and metastasis of ESCC cells. We found that the expression of Pol ι is significantly higher in ESCCs with lymph node metastasis compared to those without lymph node metastasis. Kaplan-Meier analysis revealed an inverse correlation between Pol ι expression and patient prognosis. The expression levels of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), two essential regulators of cells' invasiveness, were positively associated with Pol ι expression in ESCC tissues. Ectopic expression of Pol ι enhanced the motility and invasiveness of ESCC cells as evaluated by wound-healing and transwell assays, respectively. A xenograft nude mouse model showed that Pol ι promotes the colonization of ESCC cells in the liver, lung and kidney. Signaling pathway analysis identified the JNK-AP-1 cascade as a mediator of the Pol ι-induced increase in the expression of MMP-2/9 and enhancement of ESCC progression. These data demonstrate the underlying mechanism by which Pol ι promotes ESCC progression, suggesting that Pol ι is a potential novel prognostic biomarker and therapeutic target for ESCC.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/enzimologia , Movimento Celular , DNA Polimerase Dirigida por DNA/metabolismo , Neoplasias Esofágicas/enzimologia , Animais , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/secundário , Linhagem Celular Tumoral , DNA Polimerase Dirigida por DNA/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Estimativa de Kaplan-Meier , Metástase Linfática , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Prognóstico , Transdução de Sinais , Fatores de Tempo , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo
17.
Oncol Rep ; 35(3): 1664-70, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26752104

RESUMO

Protein reversionless 3-like (REV3L), the catalytic subunit of DNA polymerase (pol) ζ, is well known to participate in error-prone translesion synthesis (TLS) with less stringent and lower processivity. Recent evidence has demonstrated that REV3L is involved in carcinogenesis and tumor progression. However, the function of REV3L remains unclear in esophageal squamous cell carcinoma (ESCC). In the present study, we examined REV3L expression in ESCC tissues and its association with clinicopathological parameters. REV3L was found to be significantly upregulated and correlated with lymph node metastasis and clinical stage in the ESCC tissues. To further investigate the potential role of REV3L in esophageal cancer, stable ESCC cell lines with suppression of REV3L expression were established. Downregulation of REV3L expression led to a decrease in cell proliferation and invasive capacity partly through suppression of cyclin D1 and survivin expression, and an increase in cellular sensitivity to 5-fluorouracil (5-FU) by induction of G1 phase arrest and apoptosis. Therefore, REV3L plays an important role in ESCC progression and chemoresistance, and is a potential diagnostic marker and therapeutic target for ESCC.


Assuntos
Carcinoma de Células Escamosas/genética , Proteínas de Ligação a DNA/biossíntese , DNA Polimerase Dirigida por DNA/biossíntese , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Esofágicas/genética , Apoptose/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , DNA Polimerase Dirigida por DNA/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Masculino , Estadiamento de Neoplasias
18.
Toxicol Res (Camb) ; 5(6): 1639-1648, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30090463

RESUMO

The numerous particular chemical/physical properties make graphene quantum dots (GQDs) attractive for various biomedical applications such as drug delivery, bioimaging and tumor photodynamic therapy (PDT). In the present study, the critical roles of hydroxyl-modified GQDs (OH-GQDs) on lung carcinoma A549 (wild type p53) and H1299 (p53-null) cells were investigated. Our data showed that a medium concentration (50 µg mL-1) of OH-GQDs significantly decreased the viability of A549 and H1299 cells. OH-GQDs treatment enhanced intracellular reactive oxygen species (ROS) generation. Furthermore, we found that treatment with ROS scavenger N-acetylcysteine (NAC) at least partially abolished the cytotoxic effect of OH-GQDs on A549 and H1299 cells. Hydroxylated GQDs lead to G0-G1 arrest and cells senescence. Signal pathway analysis revealed that OH-GQDs activated the expression of p21 in both a p53-dependent and -independent manner. Consistent with this, OH-GQDs could also inhibit the phosphorylation of Rb in both A549 and H1299 cells. These findings provide valuable information for the consideration of biomedical application of GQDs in the future.

19.
Int J Biol Sci ; 11(12): 1458-68, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26681925

RESUMO

BACKGROUND & AIMS: High doses of radiation induce severe DNA damage in intestinal epithelial cells, especially crypt cells, and cause intestinal injury, but the underlying molecular mechanisms remain unclear. Krüppel-like factor 5 (KLF5), a zinc finger-containing transcription factor, is induced by various stress stimuli and is involved in cell proliferation and survival. The role of KLF5 in radiation-induced intestinal injury was investigated here. METHODS: Wild type mice were treated with 8 or 15 Gy total body irradiation (TBI). KLF5 content and cellular localization in the small intestines of irradiated mice were detected by Western blot and immunohistochemical analysis. Mice with intestinal-specific knockdown of KLF5 (Vil-Cre; Klf5(fl/+) mice) were generated and their response to radiation was compared with controls. Morphological changes were determined by hematoxylin and eosin staining. Proliferation was examined by Ki67 immunostaining. The molecular response of the small intestine after KLF5 knockdown was investigated using microarrays. RESULTS: KLF5 expression correlated with the progression of intestinal damage. Decreased levels of KLF5 in the gut were associated with increased damage to the intestinal mucosa and reduced epithelial proliferation after TBI. Our microarray data disclosed that KLF5 knockdown down-regulated genes related to DNA damage repair pathways such as nucleotide excision repair, mismatch repair, non-homologous end joining and the Fanconi anemia pathway, which may suggest a novel function of KLF5. CONCLUSIONS: Our study illustrates that KLF5 may modulate DNA repair pathways to prevent intestinal injury induced by TBI. KLF5 signaling provides a novel field for identification of potential therapeutic targets for the treatment of radiation-induced intestinal damage.


Assuntos
Proliferação de Células/fisiologia , Dano ao DNA , Reparo do DNA , Mucosa Intestinal/citologia , Intestino Delgado/efeitos da radiação , Fatores de Transcrição Kruppel-Like/fisiologia , Animais , Regulação para Baixo , Intestino Delgado/citologia , Fatores de Transcrição Kruppel-Like/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL
20.
Int J Biol Sci ; 11(9): 1026-35, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26221070

RESUMO

The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) is a critical component of the non-homologous end-joining pathway of DNA double-stranded break repair. DNA-PKcs has also been shown recently functioning in mitotic regulation. Here, we report that DNA-PKcs negatively regulates the stability of Cyclin B1 protein through facilitating its ubiquitination mediated by Cdh1 / E 3 ubiquitin ligase APC/C pathway. Loss of DNA-PKcs causes abnormal accumulation of Cyclin B1 protein. Cyclin B1 degradation is delayed in DNA-PKcs-deficient cells as result of attenuated ubiquitination. The impact of DNA-PKcs on Cyclin B1 stability relies on its kinase activity. Our study further reveals that DNA-PKcs interacts with APC/C core component APC2 and its co-activator Cdh1. The destruction of Cdh1 is accelerated in the absence of DNA-PKcs. Moreover, overexpression of exogenous Cdh1 can reverse the increase of Cyclin B1 protein in DNA-PKcs-deficient cells. Thus, DNA-PKcs, in addition to its direct role in DNA damage repair, functions in mitotic progression at least partially through regulating the stability of Cyclin B1 protein.


Assuntos
Proteínas Cdh1/metabolismo , Ciclina B1/metabolismo , Proteína Quinase Ativada por DNA/metabolismo , Proteínas Cdh1/genética , Ciclo Celular/genética , Ciclo Celular/fisiologia , Ciclina B1/genética , Proteína Quinase Ativada por DNA/genética , Citometria de Fluxo , Células HeLa , Humanos , Imunoprecipitação , Estabilidade Proteica , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Ubiquitinação/genética , Ubiquitinação/fisiologia
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