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Now showing items 1 - 16 of 79

  • Prognostic value of DKK2 from the Dickkopf family in human breast cancer

    Shao, You-Cheng   Nie, Xiao-Cui   Song, Guo-Qing   Wei, Yan   Xia, Pu   Xu, Xiao-Yan  

    Breast cancer is one of the most frequently diagnosed types of cancer with a high mortality and malignancy rate in women worldwide. The Dickkopf (DKK) protein family, as a canonical Wnt/beta-catenin pathway antagonist, has been implicated in both physiological and pathological processes. This study aimed to comprehensively characterize the prognostic value and elucidate the mechanisms of DKKs in breast cancer and its subtypes. Firstly, DKK mRNA expression and corresponding outcome were analyzed by means of the Gene Expression-Based Outcome for Breast Cancer Online (GOBO) platform based on PAM50 intrinsic breast cancer subtypes. Subsequently, we extracted breast cancer datasets from the Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) to validate the expression profile and prognostic values from the GOBO platform. Moreover, a protein-protein network was created and functional enrichment was conducted to explore the underlying mechanisms of action of the DKKs. In addition, we uncovered the genetic and epigenetic alterations of DKK2 in breast cancer. The main finding of this study was the differential roles of DKKs in the PAM50 subtypes of breast cancer analyzed. The overall trend was that a high level of DKK2 was associated with a good survival in breast cancer, although it played an opposite role in the Normal-like subtype. We also found that DKK2 carried out its functions through multiple signaling pathways, not limited to the Wnt/beta-catenin cascade in breast cancer. Finally, we used our own data to validate the bioinformatics analysis data for DKK2 by RT-qPCR. Taken together, our findings suggest that DKK2 may be a potential prognostic biomarker for the Normal-like subtype of breast cancer. However, the prognostic role of DKKs in the subtypes of breast cancer still requires validation by larger sample studies in the future.
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  • Epithelial-mesenchymal transition and gastric cancer stem cell

    Xia, Pu   Xu, Xiao-Yan  

    Gastric cancer remains a big health problem in China. Gastric cancer cells contain a small subpopulation of cells that exhibit capabilities of differentiation and tumorigenicity. A putative explanation for ineffective therapy is the presence of cancer stem-like cells. Side population cells, which have cancer stem-like cells' property, are characterized by the high efflux ability of Hoechst 33342 dye. Side population cells have been isolated from gastric cancer cell lines in previous studies. The epithelial-mesenchymal transition is very important in the invasion and metastasis of epithelial-derived cancers. More and more studies showed that gastric cancer stem-like cells possess high invasive ability and epithelial-mesenchymal transition property. A brief overview of the recent advancements in gastric cancer stem-like cells and epithelial-mesenchymal transition will be helpful for providing novel insight into gastric cancer treatment.
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  • Genome-Wide Screening of Aberrant Methylation Loci for Nonsyndromic Cleft Lip

    Xu, Xiao-Yan   Wei, Xiao-Wei   Ma, Wei   Gu, Hui   Liu, Dan   Yuan, Zheng-Wei  

    Background: The pathogenicity of cleft lip (CL) is pretty complicated since it is influenced by the interaction of environment and genetic factors. The purpose of this study was to conduct a genome-wide screening of aberrant methylation loci in partial lesion tissues of patients with nonsyndromic CL (NSCL) and preliminarily validate candidate dysmethylated genes associated with NSCL. Methods: Fifteen healthy and sixteen NSCL fetal lip tissue samples were collected. The Infinium HumanMethylation450 BeadChip was used to screen aberrant methylation loci in three NSCL and three healthy lip tissues. The differential methylation sites and functions of the annotated genes between NSCL and healthy lip tissues were analyzed using minfi package of R software, cluster analysis, Gene Ontology (GO) annotation, and metabolic pathway annotation. Gene expression was assessed in nine differentially methylated genes by real-time polymerase chain reaction (PCR). The transcriptions mRNA levels of three out of nine candidate genes were downregulated remarkably in NSCL lip tissues, and these three genes' abnormal methylation loci were validated by pyrosequencing in 16 NSCL cases and 15 healthy cases. Results: In total, 4879 sites in the genes of NSCL odinopoeia fetuses showed aberrant methylation when compared with normal lip tissue genome. Among these, 3661 sites were hypermethylated and 1218 sites were hypomethylated as compared to methylation levels in healthy specimens. These aberrant methylation sites involved 2849 genes and were widely distributed among the chromosomes. Most differentially methylated sites were located in cytosine-phosphoric acid-guanine islands. Based on GO analysis, aberrantly methylated genes were involved in 11 cellular components, 13 molecular functions, and a variety of biological processes. Notably, the transcription of DAB], REELIN, and FYN was significantly downregulated in lesion tissues of NSCL fetus (P < 0.05). Pyrosequencing results validated that there were two loci in DAB] with high methylation status in patient tissues (P < 0.05). Conclusions: We detected numerous aberrantly methylated loci in lesion tissues of NSCL fetus. Aberrant gene expression in the REELIN signaling pathway might be related with NSCL. Decreased transcription of DAB], a member of REELIN signal pathway, resulted from its abnormal high methylation, which might be one of the factors underlying the occurrence of NSCL.
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  • Genome-Wide Screening of Aberrant Methylation Loci for Nonsyndromic Cleft Lip

    Xu, Xiao-Yan   Wei, Xiao-Wei   Ma, Wei   Gu, Hui   Liu, Dan   Yuan, Zheng-Wei  

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  • Tim-4 Inhibits NO Generation by Murine Macrophages.

    Xu, Li-yun   Qi, Jian-ni   Liu, Xiao   Ma, Hong-xin   Yuan, Wei   Zhao, Pei-qing   Liang, Xiao-hong   Xu, Yong   Wang, Hong-xing   Xu, Xiao-yan   Wang, Wei   Ma, Chun-hong   Gao, Li-fen  

    OBJECTIVE: T cell immunoglobulin- and mucin-domain-containing molecule-4 (Tim-4) receives much attention as a potentially negative regulator of immune responses. However, its modulation on macrophages has not been fully elucidated so far. This study aimed to identify the role of Tim-4 in nitric oxide (NO) modulation.; METHODS: Macrophages were stimulated with 100 ng/ml LPS or 100 U/ml IFN-gamma. RT-PCR was performed to detect TIM-4 mRNA expression. Tim-4 blocking antibody and NF-kappaB inhibitory ligand were involved in the study. NO levels were assayed by Griess reaction. Phosphorylation of NF-kappaB, Jak2 or Stat1 was verified by western blot.; RESULTS: Tim-4 was up-regulated in murine macrophages after interferon-gamma (IFN-gamma) stimulation. Tim-4 over-expression decreased NO production and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS) or IFN-gamma-stimulated macrophages. Consistently, Tim-4 blockade promoted LPS or IFN-gamma-induced NO secretion and iNOS expression. Tim-4 over-expression decreased LPS-induced nuclear factor kappa B (NF-kappaB) p65 phosphorylation in macrophages, which was abrogated by NF-kappaB inhibitory ligand. On the contrary, Tim-4 blocking increased LPS-induced NF-kappaB signaling, which was also abrogated by NF-kappaB inhibition. In addition, Tim-4 blockade promoted Jak2 and Stat1 phosphorylation in IFN-gamma stimulated macrophages.; CONCLUSION: These results indicate that Tim-4 is involved in negative regulation of NO production in macrophages, suggesting the critical role of Tim-4 in immune related diseases.=20
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  • Prognostic value of circulating CD133(+) cells in patients with gastric cancer

    Xia, Pu   Song, Chang-Liang   Liu, Jin-Fang   Wang, Dan   Xu, Xiao-Yan  

    ObjectivesGastric cancer is an important cause of cancer-related mortality worldwide (1). There is increasing evidence that the existence of cancer stem cells (CSC) is responsible for tumour formation and maintenance. Materials and methodsThe present study was designed to recognise circulating CSCs from blood samples of patients with gastric cancer, using CD133 and ABCG2 as potential markers. CD133(-), CD133(+)ABCG2(-) and CD133(+)ABCG2(+) cells lines were analysed by flow cytometry, immunofluorescence staining, western blotting and real-time PCR. Furthermore, functional assays (clonogenic assay invitro and tumourigenic assay invivo) were also performed using these cell lines. ResultsHigher percentages of CD133(+) cells were identified in blood samples from gastric cancer patients compared to normal controls. In addition, we found by using Kaplan-Meier analysis, that numbers of CD133(+) cells correlated with poor prognosis gastric cancer patients. Finally, tumourigenic properties of CD133(+)ABCG2(+) cells were determined invitro and invivo. ConclusionsOur invitro and invivo experiments demonstrated that CD133(+)ABCG2(+) cells exhibited well-known CSC characteristics; thus when circulating they could be used as a prognostic marker for gastric cancer.
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  • The roles of REIC gene and its encoding product in gastric carcinoma.

    Xu, Xiao-yan   Xia, Pu   Yu, Miao   Nie, Xiao-cui   Yang, Xue   Xing, Ya-nan   Liu, Yun-peng   Takano, Yasuo   Zheng, Hua-chuan  

    REIC is downregulated in immortalized cell lines compared with the parental normal counterparts. It may inhibit colony formation, tumor growth and induce apoptosis. Here, gastric carcinoma or epithelial cells transfected with REIC-expressing plasmid, its siRNA or treated with recombinant REIC were subjected to the phenotypes' measurement or related molecules' detection. REIC expression was examined in gastric carcinomas by RT-PCR, western blot and immunohistochemistry. REIC overexpression or treatment resulted in a low karyoplasmic ratio and proliferation, G=E2=82=81 arrest, high apoptosis, low migration, invasion or lamellipodia formation in AGS cells. REIC knockdown caused the opposite in GES-1 cells. Anti-REIC antibody blocked the effects of REIC overexpression on proliferation, G=E2=82=81/S progression and apoptosis. Ectopic REIC expression downregulated the expression of beta-catenin, phosphorylated S6K (Thr389), phosphorylated Akt1/2/3 (Ser473), cyclin D2 and E, WAVE2 and upregulated phosphorylated mTOR (Ser2448) expression and the mRNA level of Akt1, Akt2, mTOR, Raptor and Rictor in AGS cells. REIC expression was negatively associated with tumor size, lymph node metastasis, dedifferentiation or poor prognosis of carcinoma. The serum REIC level was significantly higher in healthy individuals than the carcinoma patients and inversely linked to tumor size by ELISA. The possible mechanisms underlying the forced REIC overexpression or recombinant REIC mediated the reversal of the aggressive phenotypes of gastric carcinoma cells are to downregulate beta-catenin and WAVE2 expression and to alter other related target proteins. Downregulated REIC expression was closely linked to aggressive behaviors and poor prognosis of gastric carcinoma.=20
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  • Effect of Rapid Thermal Annealing Ambient on Photoluminescence of ZnO Films

    Xu, Xiao-Yan   Ma, Xiang-Yang   Jin, Lu   Yang, De-Ren  

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  • Cloning and characterization of TIMP-2b gene in grass carp

    Xu, Xiao-Yan   Shen, Yu-Bang   Yang, Xiao-Meng  

    Tissue inhibitors of metalloproteinases (TIMPs) are the primary inhibitors of matrix metalloproteinases (MMPs) in tissues. In this study, a TIMP-2 gene was isolated from grass carp Ctenopharyngodon idella (CiTIMP-2b) and characterized. This cDNA sequence encoded a signal peptide, N- and C-terminal domains. CiTIMP-2b is highly homologous to the orthologous in zebrafish and other teleosts, suggesting TIMP-2b is highly conserved during teleost evolution. CiTIMP-2b gene is expressed in a wide range of tissues including blood, brain, muscle, trunk kidney, liver, head kidney, skin, spleen, heart, gill, intestine and fin, with the highest level of transcripts in spleen. Upon challenge with Aeromonas hydrophila, its expression was significantly up-regulated in all tissues. The CiTIMP-2b transcript is present at unfertilized eggs, which suggests that CiTIMP-2b transcript is maternally inherited. These results suggest that the CiTIMP-2b would play an important role in the A. hydrophila-related diseases and early embryonic development stages in grass carp. Crown Copyright (C) 2011 Published by Elsevier Inc. All rights reserved.
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  • Numerical simulations of magnetic reconnection in the lower solar atmosphere

    Xu, Xiao-Yan   Fang, Cheng   Ding, Ming-De   Gao, Dan-Hui  

    Observations indicate that Ellerman bombs (EBs) and chromospheric microflares both occur in the lower solar atmosphere, and share many common features, such as temperature enhancements, accompanying jet-like mass motions, short lifetime, and so on. These strongly suggest that EBs and chromospheric microflares could both probably be induced by magnetic reconnection in the lower solar atmosphere. With gravity, ionization and radiation considered, we perform two-dimensional numerical simulations of magnetic reconnection in the lower solar atmosphere. The influence of different parameters, such as intensity of the magnetic field and anomalous resistivity, on the results are investigated. Our result demonstrates that the temperature increases are mainly due to the joule dissipation caused by magnetic reconnection. The spectral profiles of EBs and chromospheric microflares are calculated with the non-LTE radiative transfer theory and compared with observations. It is found that the typical features of the two phenomena can be qualitatively reproduced.
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  • MicroRNA-induced negative regulation of TLR-5 in grass carp, Ctenopharyngodon idella

    Xu, Xiao-Yan   Shen, Yu-Bang   Fu, Jian-Jun   Yu, Hong-Yan   Huang, Wen-Ji   Lu, Li-Qun   Li, Jia-Le  

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  • The association of genetic polymorphisms with cerebral palsy: a meta-analysis

    Wu, De   Zou, Yan-Feng   Xu, Xiao-Yan   Feng, Xiao-Liang   Yang, Li   Zhang, Gong-Chun   Bu, Xi-Song  

    AIM The aim of ourmeta-analysis was to summarize quantitatively the association of genetic polymorphisms with cerebral palsy (CP).METHOD We identified 16 studies on the association of genetic polymorphisms with CP in Pubmed, Elsevier Science Direct, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, and Wanfang. Eleven of these studies (involving a total of 2533 cases and 4432 controls) were used in the current meta-analysis. A study was included if (1) it was published up to September 2010 and (2) it was a case-control study. We excluded one study of family members because the analysis was based on linkage considerations. Meta odds ratios and 95% confidence intervals based on fixed-effectsmodels or random-effects models were dependent on Cochran's Q statistic. We examined the relationship between alleles, as well as genotypes and susceptibility to CP.RESULTS Meta-analysis was performed for 17 genetic polymorphisms: apolipoprotein E (epsilon 2, epsilon 3, epsilon 4), methylenetetrahydrofolate reductase (MTHFR) (rs1801133), coagulation factor II (rs1799963]), coagulation factor V (rs6025), coagulation factor VII (rs5742910/rs6046), interleukin-6 (IL-6) (rs1800795), endothelial nitric oxide (rs1800779/rs1799983/rs3918226), fibrinogen beta-polypeptide (rs1800790), plasminogen activator inhibitor 1 (rs1799768/rs7242), TNF-beta lymphotoxin alpha precursor (rs1041981), adducin 1 (alpha) (rs4961), ADRB2 (rs1042714), and tumour necrosis factor alpha (rs1800629). We found a significant association between CP and IL-6 (rs1800795) [C vs G: odds ratio (OR) 1.79, 95% confidence interval (CI) 1.44-2.22, p < 0.001; CC+GC vs GG: OR 1.72, 95% CI 1.29-2.29, p=0.002; CC vs GG+GC: OR 2.17, 95% CI 1.52-3.09, p < 0.001], but no other genetic polymorphisms.INTERPRETATION This meta-analysis demonstrated that CP is associated with the genetic polymorphism IL-6 (rs1800795).
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  • The role of Reg IV gene and its encoding product in gastric carcinogenesis

    Zheng, Hua-chuan   Xu, Xiao-yan   Yu, Miao   Takahashi, Hiroyuki   Masuda, Shinji   Takano, Yasuo  

    Although the biologic function of Reg IV is poorly understood, it has been reported that Reg IV is a potent activator of the epidermal growth factor receptor/Akt/AP-1 signaling pathway in colon cancer cells and closely linked with the inhibition of apoptosis. To clarify the role of Reg IV in gastric carcinogenesis and subsequent progression, we examined its expression by immunohistochemistry and in situ hybridization on tissue microarray containing gastric carcinoma, adjacent nonneoplastic mucosa, adenoma, intestinal metaplasia, or gastritis. Gastric carcinoma cell lines (MKN28, AGS, MKN45, KATO-III, and HGC-27) were studied for Reg IV expression by Western blot and reverse transcriptase polymerase chain reaction followed by sequencing. Frozen samples of gastric carcinoma and adjacent nonneoplastic mucosa were subjected to Western blot, and patient serum, to enzyme-linked immunosorbent assay for Reg IV. Gastric carcinoma cell lines showed different levels of Reg IV mRNA and its encoding protein. The Reg IV protein expression was gradually decreased from intestinal metaplasia, adenoma, and carcinoma to gastritis (P < .05). The positive rate of its mRNA was higher in intestinal metaplasia than carcinoma or nonneoplastic mucosa (P < .05). Elevated serum Reg IV level in gastric carcinoma patients was detected in comparison with that in health individuals (P < .05). Reg IV expression was significantly correlated with the MUC-2 and MUC-5AC expression (P < .05). Among histologic subtypes of the World Health Organization, signet ring cell carcinoma more frequently expressed Reg IV than the others (P < .05), whereas it is the converse for the poorly differentiated group (P < .05). Our study indicated that Reg IV expression experienced up-regulation in gastric intestinal metaplasia and adenoma and then down-regulation with malignant transformation of gastric epithelial cells. It was suggested that Reg IV expression should be considered as a good biomarker for gastric precancerous lesions and was especially related to the histogenic pathway of signet ring cell carcinoma. (c) 2010 Elsevier Inc. All rights reserved.
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  • Study of Harmonic Detection Methods under Non-Ideal Conditions in Ship Power Network

    Xu, Xiao-Yan   Mindykowski, Janusz   Tarasiuk, Tomasz   Cheng, Chen  

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  • Characterization of p70 S6 Kinase 1 in Early Development of Mouse Embryos

    Xu, Xiao-Yan   Zhang, Zhe   Su, Wen-Hui   Zhang, Yang   Yu, Yan-Qiu   Li, Yan-Xiao   Zong, Zhi-Hong   Yu, Bing-Zhi  

    The mTOR kinase controls cell growth, proliferation, and survival through two distinct multiprotein complexes mTORC1 and mTORC2. p70 S6 Kinase 1 (S6K1) is characterized as downstream effector of mTOR. Until recently, the connection between S6K1 and mTORC1 /mTORC2 during the early development of mouse embryos has not been well elucidated. Here, the expression level of total S6K1 and its phosphorylation at Thr389 was determined in four phases of one-cell embryos. S6K1 was active throughout the cell cycle especially with higher activity in G2 and M phases. Rapamycin decreased the activity of M-phase promoting factor (MPF) and delayed the first mitotic cleavage. Down-regulating mTOR and raptor reduced S6K1. phosphorylation at Thr389 in one-cell embryos. Furthermore, rapamycin and microinjection of raptor shRNA decreased the immunofluorescent staining of Thr389 phospho-S6K1. It is proposed that mTORC1 may be involved in the control of MPF by regulating S6K1 during the early development of mouse embryos. Developmental Dynamics 238:302.5-3034, 2009. (C) 2009 Wiley-Liss, Inc.
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  • Overexpression of oncostatin M receptor regulates local immune response in glioblastoma

    Guo, Qing   Guan, Ge-fei   Cao, Jing-yuan   Zou, Cun-yi   Zhu, Chen   Cheng, Wen   Xu, Xiao-yan   Lin, Zhi-guo   Cheng, Peng   Wu, An-hua  

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