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Tobacco can induce reactive oxygen species (ROS) production extensively in cells, which is a major risk factor for oral leukoplakia (OLK) development. Peroxiredoxin 1 (Prx1) is a key antioxidant protein, upregulated in a variety of malignant tumors. We previously found that nicotine, the main ingredient of tobacco, promotes oral carcinogenesis via regulating Prx1. The aim of the present study was to screen and identify the Prx1 interacting proteins and investigate the mechanisms of nicotine on the development of OLK. Through liquid chromatography-tandem mass spectrometry combined with bioinformatics analysis, the candidate Prx1 interacting proteins of cofilin-1 (CFL1), tropomyosin alpha-3 chain (TPM3), and serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (PPP2R1A) were screened in human dysplastic oral keratinocyte cells treated with nicotine. CFL1, TPM3, and PPP2R1A were highly expressed in human OLK tissues. The expression of CFL1 increased and the expression of PPP2R1A decreased in OLK of smokers compared to that in OLK of non-smokers. Nicotine upregulated CFL1 and downregulated PPP2R1A in 4-nitro-quinoline-1-oxide (4NQO)-induced OLK tissues in mice in part dependent on Prx1. Furthermore, the in-situ interaction of CFL1, TPM3, and PPP2R1A with Prx1 were validated in human OLK tissues. Our results suggested that tobacco might promote the development of OLK via regulating Prx1 and its interacting proteins CFL1 and PPP2R1A.
Assuntos
Animais , Camundongos , Leucoplasia Oral/induzido quimicamente , Peroxirredoxinas/metabolismo , Nicotina , Proteínas de Transporte , Proteínas de Homeodomínio , CarcinogêneseRESUMO
In this study,the current status for breast diseases in a region with high-incidence of cervical cancer were epidemiologically investigated.From March to August,2009,17618 women,from Wufeng area of Hubei province,China,were recruited to screen breast diseases by using breast infrared diagnostic apparatus.Other diagnostic methods,such as B-mode ultrasound,X-ray mammography,needle biopsy and pathological examination were,if necessary,used to further confirm the diagnosis.The screening showed that 5990 of 17618 cases (34.00％) had breast diseases,5843 (33.16％) had mammary gland hyperplasia,48 (0.27％) had breast fibroadenoma,ll (0.06％) had breast carcinoma,and 88 (0.50％) had other breast diseases.The peak morbidity of breast cancer was found in the women aged 50-0 ages.The morbidity of breast cancer was significantly increased in women elder than or equal to 50 years old (n=8,0.157％) in comparison with that in the subjects younger than 50 years old (n=3,0.024％) (u=2.327,P＜0.05).It was shown that the occurrence of breast diseases was concentrated in women aged 20-40 years,while the total morbidity reached its peak at the age of 30 years and then decreased sharply after age of 40.Compared with the patients elder than or equal to 40 years old (n=3289,27.46％),the morbidity rate of breast diseases was significantly increased in women less than 40 years old (2648 cases,47.18％; P＜0.001).However,there was no significant difference in the morbidity of breast diseases between the age group of 20-29 years and that of 30-39 years (P=0.453),and both of them were high.There was no significant association between the morbidity of breast diseases and cervical cancer.Since the morbidity of breast diseases was higher among young women,more attention should be paid to the screening of breast diseases among young women for early diagnosis.
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Chemotherapy is the preferred therapeutic approach for advanced ovarian cancer,but a suceessful long-term treatment is prevented by the development of drug resistance.Recent works have underlined the involvement of non-coding RNAs,microRNAs (miRNAs) in cancer development,with several conjectures regarding their possible involvement in the evolution of drug resistance.This study is to investigate the promoting effects and mechanism of miR-125b involved in the development of chemoresistance in ovarian cancer.The different expression of miR-125b in cisplatin-sensitive ovarian cancer cell line (OV2008) and its resistant variant (C13*) was identified by real-time PCR.An in vitro cytotoxicity assay and apoptosis assay using CCK-8 assay and flow cytometry,were carried out to detect the effect of miR-125b and Bak1 on cisplatin resistance of cells.Real-time PCR,Western blotting and luciferase reporter assay were used to detect whether Bak1 is a target of miR-125b.As compared with OV2008 cells,the expression levels of miR-125b in C13* cells were increased.It was found that the up-regulation of microRNA-125b caused a marked inhibition of cisplatin-induced cytotoxicity and apoptosis and a subsequent increase in the resistance to cisplatin in OV2008 and C13* cells.Moreover,Bakl was a direct target of miR-125b,and down-regulation of Bak1 suppressed cisplatin-induced apoptosis and led to an increased resistance to cisplatin.Our study indicates that miR-125b has a significantly promoting effect on chemoresistance of C13* cells and up-regulation of miR-125b expression contributes to cisplatin resistance through suppression of Bakl expression.This finding has important implications in the development of targeted therapeutics for overcoming cisplatin resistance in ovarian cancer.
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Recent evidence has suggested that Akt2 plays an important role in the protection of cells from paclitaxel(PTX)-induced apoptosis and control of the cell cycle.In addition,some scholars suggested that the PTX sensitivity depends on a functional spindle assembly checkpoint.In the present study,we investigated the role of the Akt2/Bub1 cross-talking in apoptosis and cell cycle after exposure of the A2780 ovarian cancer cells to paclitaxel(PTX).Recombinant expression plasmid WT-Akt2 was transfected into A2780 cells by lipofectamine2000,and then the expression level of Akt2 gene was detected by using RT-PCR and Western blotting.Cell apoptosis and cell cycle were detected by flow cytometry and Hoechst 33342 staining after treatment with PTX.Moreover,we compared the expression level of Bubl in different groups by Western blotting.Our study showed that up-regulation of Akt2 contributed to A2780 ovarian cancer cells overriding PTX-induced G2/M arrest,and inhibited Bub1 expression.Our findings might shed light on the molecular mechanism of PTX-induced resistance in ovarian cancer and help develop novel anti-neoplastic strategies.
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By using a yeast two-hybrid system,a yeast two-hybrid bait vector was constructed and identified for screening of the HPV18 E6-interacting proteins,and its effects on the growth of yeast cells and the activation of reporter genes were investigated.Total mRNA extracted from Hela cells was reversely transcribed into cDNA.Fragment of HPV18 E6 cDNA was amplified using RT-PCR and directly ligated to the pGBKT7 vector.The recombinant plasmid was confirmed by restriction endonuclease analysis and DNA sequencing.The recombinant pGBKT7-HPV18 E6 plasmid and empty pGBKT7 vector were transformed into the yeast cell AH109,respectively.After they were cultured respectively in YPDA liquid medium and nutrition-deficient culture medium,their toxicity and transcriptional activation were tested by both the phenotype assay and the color assay.The bait plasmid HPV18 E6 was successfully obtained.After being cultured in YPDA liquid medium for 16h,the A600 nm values of two yeast fluids were 0.98±0.03 and 0.99±0.02,respectively.The recombinant pGBKT7-HPV18 E6 plasmid and empty pGBKT7 vector could grow to white colonies on SD/-Trp/X-α-gal plates,while no colony could survive on SD/-His/-Trp/X-α-gal,SD/-Ade/-Trp/X-α-gal plates,indicating that the bait plasmid pGBKT7-HPV18 E6 was constructed successfully and expressed correctly,and could not activate the transcription of reporter gene alone.The yeast two-hybrid GAL4 system 3 can be utilized to find HPV18 E6 interacting proteins.
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In this article, the status of spindle assembly checkpoint and the alteration of its major component, Mad2 protein level were examined in A2780 and SKOV3 ovarian cancer cell lines. Recombinant eukaryotic expression plasmid pEGFP-Mad2 was transfected into paclitaxel-resistant SKOV3 cells and Mad2 protein was knocked down by Mad2-specific siRNA in paclitaxel-sensitive A2780 cells. Then the expression level of Mad2 gene was detected by Western blotting. Flow cytometry revealed that SKOV3 cells were not fully arrested in G2/M phase in contrast to A2780 cells in the presence of paclitaxel. However, paclitaxel sensitivity assay showed that sensitivity to paclitaxel was reversed after the transfection in both cell lines in terms of number of cells arrested at G2/M phase and the expression of Bcl-2 was significantly changed. These results suggest that weakened spindle checkpoint with reduced expression of Mad2 is associated with resistance to paclitaxel in ovarian cells and Bcl-2 may be involved in this process.
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The purpose of this study was to pool information in epithelial ovarian cancer by combining studies using Affymetrix expression microarray datasets made at different laboratories to identify novel biomarkers.Epithelial microarray expression information across laboratories was screened and combinedafter preprocessing raw microarray data,then ANOVA and unpaired T test statistical analysis was performed for identifying differentially expressed genes(DEGs),followed by clustering and pathway analysis for these DEGs.In this work,we performed a combination analysis on microarrays from three different laboratories using gene expression data on ovarian cancer and obtained a list of differential expression profiles identified as potential candidate in aggressiveness of ovarian cancer.The clustering and pathway analysis explored the different molecular basis of different ovarian cancer stages and potential important regulatory pathways in ovarian cancer development.Our results showed that combination of microarray data from different laboratories in the same platforms may overcome biases derived from probe design and technical features,thereby accelerating the identification of trustworthy DEGs,and demonstrating the advantage of integrative analysis in gene expression studies on epithelial ovarian cancer research.
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In order to investigate the role of the PTEN expression in carcinogenesis and develop-ment of endometrial carcinoma and clarify whether and how PTEN and PI3K/Akt pathway relate to endometrial carcinoma,the expression of PTEN and phospho-Akt was detected by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) methods and Western-blot from 24 cases of endomctrial carcinoma,10 cases of endometrial atypical hyperplasia,10 cases of endometrial hy-perplasia,and 10 cases of normal endometrium.SP immunohistochemical methods were used to measure levels of PTEN protein expression in following 5 study groups:31 cases of endometrium in proliferative phase,30 cases of endometrium in secretory phase,71 cases of endometrial hyperplasia,25 cases of atypical hyperplasia and 73 cases of endometrial carcinoma.Immunostaining score of PTEN was 3.39±0.15 in proliferative phase,1.90±0.21 in secretory phase,3.34～0.29 in endometrial hyperplasia,0.624±0.11 in atypical hyperplasia,and 0.74±0.19 in endometrial carcinoma,respectively.PTEN mRNA relative value in normal endometrium,endometrial hyperplasia,endometrial atypical hyperplasia,and endometrial carcinoma was 2.45±0.51,2.32±0.32,0.46±0.11,and 0.35±0.13 respec-tively.The expression levels of PTEN mRNA and protein in patients with endometrial carcinoma and atypical hyperplasia were significantly lower than in those of proliferative phase and with endo-metrial hyperplasia.The level of PTEN expression in patients with endometrial carcinoma was sig-nificantly related to tissue type (P<0.005),differentiation (P<0.05) and clinical stage (P<0.05),but not to depth of myometrium invasion (P>0.05).Western blot analysis revealed that Phospho-Akt level in PTEN negative cases was significantly higher,and there was a negative correlation between PTEN and phospho-Akt (r=- 0.8973,P<0.0001).It was suggested that loss of PTEN expression was an early event in endometrial tumorigenesis.The phosphorylation of Akt induced by the loss of PTEN took part in the tumorigenesis and development of endometrial carcinoma.
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The correlation between aquaporin 1 (AQP1) and hypoxia-inducible factor 1 (HIF 1) in breast cancer tissues was preliminarily studied. In 155 cases of breast cancer, the expression levels of AQP1 were detected by immunohistochemisty in HIF1-positive group or HIF1-negative group, and the correlation between AQP1 and HIF1 was analyzed. The overexpression of AQP1 and HIF1 were observed in 155 cases of breast cancer tissues. The expression level of AQP1 in HIF1-positive group was significantly higher than that in HIF1-negative group. The positive expression rate of AQP1 was 296.55±24.67 and 168.37±37.53 in HIF1-positive group and HIF1-negative group respectively with the difference being very significant between them (P<0.001). It was concluded that AQP1 was overexpressed in the HIF1-positive group and there were some correlations between AQP1 and HIF1, suggesting they interact each other and regulate the oncogenesis of breast cancer.
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To study the apoptosis induced by cisplatin in cervical cancer cell line HeLa and its mechanism, cell growth inhibition of cisplatin on HeLa cells was analyzed by MTT assay. Cell apoptosis was examined by cytometry and Hoechst33258 staining after treatment with cisplatin. The ef- fects of cisplatin on transcription of E6 were analyzed by RT-PCR. The protein expressions of E6, p53, p21, Bax and Bcl-2 were studied by Western blotting. Cisplatin inhibited proliferation in a time- and dose-dependant manner. Cytometically, sub-G1 peak showed higher apoptosis rates in the ex- perimental group than those in the control. Hoechst33258staining exhibited apoptosis induced by cis- platin. RT-PCR revealed that cisplatin decreased transcription of E6. Western blotting showed that cisplatin decreased protein expression of E6 and increased protein expression of p53, p21and Bax. It had no effect on protein expression of Bcl-2. It is concluded that cisplatin can induce apoptosis in HeLa cells by suppressing HPV E6 and thereby restoring the function of p53.
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The aim of the present study was to explore the differentially expressed genes in the blood vessel endothelial cells (BVECs) between diffuse large B-cell lymphoma (DLBCL) and reac- tive lymph node hyperplasia (RLNH), and to perform an initial bioinformatics analysis on a novel gene, C20orf14, which is highly expressed in lymph node of lymphoma. The mRNA of the tissue from the BVECs of DLBCL and RLNH tissues was labeled with biotin respectively and hybridized with expression profile microarray, and the differentially expressed genes were obtained. Initial bio- informatics analysis was performed on a novel gene named C20orf14. Its gene structure, genomic lo- calization, the physical and chemical characteristics of the putative protein, subcellular localization, functional domain etc. were predicted, and the systematic evolution analysis was performed on the similar proteins among several species. By using expression profile microarray, many differentially expressed genes were uncovered. The efficient bioinformatics analysis have fundamentally identified that C20orfl4 was a nuclear protein, and may be involved in the post-transcription modification of mRNA. Therefore, microarray is an efficient and high throughout strategy for the detection of differ- entially expressed genes, and C20orf14 is thought to be a potential target for tumor metastasis re- searches by bioinformatics analysis.
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To screen for novel binding proteins interacting with high-risk HPV 18 E6 oncogene, the strain AH109 was transformed with pGBKT7-HPV18 E6 plasmid, and subsequent transference was utilized to screen for interacting proteins with HPV 18 E6 in human Hela cDNA library. HPVl8 E6 mRNA was expressed in yeast and there was no self-activation and toxicity in AH109. Seven proteins that interacted with HPV18 E6, including transmembrane protein 87B, phosphonoformate im- muno-associated protein 5, vimentin, KM-HN-1 protein, dedicator of cytokinesis 7, vaccinia related kinase 2 and a hypothetical protein, were identified. It was suggested that yeast two-hybrid system is an efficient for screening interacting proteins. The high-risk HPV 18 E6 oncogene may interact with the proteins, which may be associated with signal transduction and transeriptional control, epithelial cell invasion and migration, as well as humoral and cellular immune etc. This investigation provides functional clues for further exploration of potential oncogenesis targets for cancer biotherapy.