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Sample records for transformed cells expressing

  1. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

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    Prabhakar Sripadi

    Full Text Available BACKGROUND: Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. METHODS AND PRINCIPAL FINDINGS: Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3 transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI mass spectrometry (MS. Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1 and PC(O-34:1 plasmalogens were displaced by PC(30:0 and PC(32:0 species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. CONCLUSIONS AND SIGNIFICANCE: We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3

  2. Direct detection of diverse metabolic changes in virally transformed and tax-expressing cells by mass spectrometry.

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    Sripadi, Prabhakar; Shrestha, Bindesh; Easley, Rebecca L; Carpio, Lawrence; Kehn-Hall, Kylene; Chevalier, Sebastien; Mahieux, Renaud; Kashanchi, Fatah; Vertes, Akos

    2010-09-07

    Viral transformation of a cell starts at the genetic level, followed by changes in the proteome and the metabolome of the host. There is limited information on the broad metabolic changes in HTLV transformed cells. Here, we report the detection of key changes in metabolites and lipids directly from human T-lymphotropic virus type 1 and type 3 (HTLV1 and HTLV3) transformed, as well as Tax1 and Tax3 expressing cell lines by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Comparing LAESI-MS spectra of non-HTLV1 transformed and HTLV1 transformed cells revealed that glycerophosphocholine (PC) lipid components were dominant in the non-HTLV1 transformed cells, and PC(O-32:1) and PC(O-34:1) plasmalogens were displaced by PC(30:0) and PC(32:0) species in the HTLV1 transformed cells. In HTLV1 transformed cells, choline, phosphocholine, spermine and glutathione, among others, were downregulated, whereas creatine, dopamine, arginine and AMP were present at higher levels. When comparing metabolite levels between HTLV3 and Tax3 transfected 293T cells, there were a number of common changes observed, including decreased choline, phosphocholine, spermine, homovanillic acid, and glycerophosphocholine and increased spermidine and N-acetyl aspartic acid. These results indicate that the lipid metabolism pathway as well as the creatine and polyamine biosynthesis pathways are commonly deregulated after expression of HTLV3 and Tax3, indicating that the noted changes are likely due to Tax3 expression. N-acetyl aspartic acid is a novel metabolite that is upregulated in all cell types and all conditions tested. We demonstrate the high throughput in situ metabolite profiling of HTLV transformed and Tax expressing cells, which facilitates the identification of virus-induced perturbations in the biochemical processes of the host cells. We found virus type-specific (HTLV1 vs. HTLV3), expression-specific (Tax1 vs. Tax3) and cell-type-specific (T lymphocytes vs. kidney

  3. Insect cell transformation vectors that support high level expression and promoter assessment in insect cell culture

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    A somatic transformation vector, pDP9, was constructed that provides a simplified means of producing permanently transformed cultured insect cells that support high levels of protein expression of foreign genes. The pDP9 plasmid vector incorporates DNA sequences from the Junonia coenia densovirus th...

  4. PRMT5 Is Upregulated in HTLV-1-Mediated T-Cell Transformation and Selective Inhibition Alters Viral Gene Expression and Infected Cell Survival

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    Amanda R. Panfil

    2015-12-01

    Full Text Available Human T-cell leukemia virus type-1 (HTLV-1 is a tumorigenic retrovirus responsible for development of adult T-cell leukemia/lymphoma (ATLL. This disease manifests after a long clinical latency period of up to 2–3 decades. Two viral gene products, Tax and HBZ, have transforming properties and play a role in the pathogenic process. Genetic and epigenetic cellular changes also occur in HTLV-1-infected cells, which contribute to transformation and disease development. However, the role of cellular factors in transformation is not completely understood. Herein, we examined the role of protein arginine methyltransferase 5 (PRMT5 on HTLV-1-mediated cellular transformation and viral gene expression. We found PRMT5 expression was upregulated during HTLV-1-mediated T-cell transformation, as well as in established lymphocytic leukemia/lymphoma cell lines and ATLL patient PBMCs. shRNA-mediated reduction in PRMT5 protein levels or its inhibition by a small molecule inhibitor (PRMT5i in HTLV-1-infected lymphocytes resulted in increased viral gene expression and decreased cellular proliferation. PRMT5i also had selective toxicity in HTLV-1-transformed T-cells. Finally, we demonstrated that PRMT5 and the HTLV-1 p30 protein had an additive inhibitory effect on HTLV-1 gene expression. Our study provides evidence for PRMT5 as a host cell factor important in HTLV-1-mediated T-cell transformation, and a potential target for ATLL treatment.

  5. Commensal bacteria drive endogenous transformation and tumour stem cell marker expression through a bystander effect.

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    Wang, Xingmin; Yang, Yonghong; Huycke, Mark M

    2015-03-01

    Commensal bacteria and innate immunity play a major role in the development of colorectal cancer (CRC). We propose that selected commensals polarise colon macrophages to produce endogenous mutagens that initiate chromosomal instability (CIN), lead to expression of progenitor and tumour stem cell markers, and drive CRC through a bystander effect. Primary murine colon epithelial cells were repetitively exposed to Enterococcus faecalis-infected macrophages, or purified trans-4-hydroxy-2-nonenal (4-HNE)-an endogenous mutagen and spindle poison produced by macrophages. CIN, gene expression, growth as allografts in immunodeficient mice were examined for clones and expression of markers confirmed using interleukin (IL) 10 knockout mice colonised by E. faecalis. Primary colon epithelial cells exposed to polarised macrophages or 4-hydroxy-2-nonenal developed CIN and were transformed after 10 weekly treatments. In immunodeficient mice, 8 of 25 transformed clones grew as poorly differentiated carcinomas with 3 tumours invading skin and/or muscle. All tumours stained for cytokeratins confirming their epithelial cell origin. Gene expression profiling of clones showed alterations in 3 to 7 cancer driver genes per clone. Clones also strongly expressed stem/progenitor cell markers Ly6A and Ly6E. Although not differentially expressed in clones, murine allografts positively stained for the tumour stem cell marker doublecortin-like kinase 1. Doublecortin-like kinase 1 and Ly6A/E were expressed by epithelial cells in colon biopsies for areas of inflamed and dysplastic tissue from E. faecalis-colonised IL-10 knockout mice. These results validate a novel mechanism for CRC that involves endogenous CIN and cellular transformation arising through a microbiome-driven bystander effect. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Methods for transforming and expression screening of filamentous fungal cells with a DNA library

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    Teter, Sarah; Lamsa, Michael; Cherry, Joel; Ward, Connie

    2015-06-02

    The present invention relates to methods for expression screening of filamentous fungal transformants, comprising: (a) isolating single colony transformants of a DNA library introduced into E. coli; (b) preparing DNA from each of the single colony E. coli transformants; (c) introducing a sample of each of the DNA preparations of step (b) into separate suspensions of protoplasts of a filamentous fungus to obtain transformants thereof, wherein each transformant contains one or more copies of an individual polynucleotide from the DNA library; (d) growing the individual filamentous fungal transformants of step (c) on selective growth medium, thereby permitting growth of the filamentous fungal transformants, while suppressing growth of untransformed filamentous fungi; and (e) measuring activity or a property of each polypeptide encoded by the individual polynucleotides. The present invention also relates to isolated polynucleotides encoding polypeptides of interest obtained by such methods, to nucleic acid constructs, expression vectors, and recombinant host cells comprising the isolated polynucleotides, and to methods of producing the polypeptides encoded by the isolated polynucleotides.

  7. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

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    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    In small-cell lung cancer cell lines resistance to growth inhibition by transforming growth factor (TGF)-beta 1, was previously shown to correlate with lack of TGF-beta receptor I (RI) and II (RII) proteins. To further investigate the role of these receptors, the expression of mRNA for RI, RII...... and beta-glycan (RIII) was examined. The results showed that loss of RII mRNA correlated with TGF-beta 1 resistance. In contrast, RI-and beta-glycan mRNA was expressed by all cell lines, including those lacking expression of these proteins. According to Southern blot analysis, the loss of type II m......RNA was not due to gross structural changes in the gene. The effect of TGF-beta 1 on expression of TGF-beta receptor mRNA (receptor autoregulation) was examined by quantitative Northern blotting in four cell lines with different expression of TGF-beta receptor proteins. In two cell lines expressing all three TGF...

  8. Mechanisms of radiation-induced neoplastic cell transformation

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    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

  9. Mechanisms of radiation-induced neoplastic cell transformation

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    Yang, T.C.H.; Tobias, C.A.

    1984-04-01

    Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table

  10. Dysregulation of gene expression in the artificial human trisomy cells of chromosome 8 associated with transformed cell phenotypes.

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    Hisakatsu Nawata

    Full Text Available A change in chromosome number, known as aneuploidy, is a common characteristic of cancer. Aneuploidy disrupts gene expression in human cancer cells and immortalized human epithelial cells, but not in normal human cells. However, the relationship between aneuploidy and cancer remains unclear. To study the effects of aneuploidy in normal human cells, we generated artificial cells of human primary fibroblast having three chromosome 8 (trisomy 8 cells by using microcell-mediated chromosome transfer technique. In addition to decreased proliferation, the trisomy 8 cells lost contact inhibition and reproliferated after exhibiting senescence-like characteristics that are typical of transformed cells. Furthermore, the trisomy 8 cells exhibited chromosome instability, and the overall gene expression profile based on microarray analyses was significantly different from that of diploid human primary fibroblasts. Our data suggest that aneuploidy, even a single chromosome gain, can be introduced into normal human cells and causes, in some cases, a partial cancer phenotype due to a disruption in overall gene expression.

  11. p53 functional impairment and high p21waf1/cip1 expression in human T-cell lymphotropic/leukemia virus type I-transformed T cells.

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    Cereseto, A; Diella, F; Mulloy, J C; Cara, A; Michieli, P; Grassmann, R; Franchini, G; Klotman, M E

    1996-09-01

    Human T-cell lymphotropic/leukemia virus type I (HTLV-I) is associated with T-cell transformation both in vivo and in vitro. Although some of the mechanisms responsible for transformation remain unknown, increasing evidence supports a direct role of viral as well as dysregulated cellular proteins in transformation. We investigated the potential role of the tumor suppressor gene p53 and of the p53-regulated gene, p21waf1/cip1 (wild-type p53 activated fragment 1/cycling dependent kinases [cdks] interacting protein 1), in HTLV-I-infected T cells. We have found that the majority of HTLV-I-infected T cells have the wild-type p53 gene. However, its function in HTLV-I-transformed cells appears to be impaired, as shown by the lack of appropriate p53-mediated responses to ionizing radiation (IR). Interestingly, the expression of the p53 inducible gene, p21waf1/cip1, is elevated at the messenger ribonucleic acid and protein levels in all HTLV-I-infected T-cell lines examined as well as in Taxl-1, a human T-cell line stably expressing Tax. Additionally, Tax induces upregulation of a p21waf1/cip1 promoter-driven luciferase gene in p53 null cells, and increases p21waf1/cip1 expression in Jurkat T cells. These findings suggest that the Tax protein is at least partially responsible for the p53-independent expression of p21waf1/cip1 in HTLV-I-infected cells. Dysregulation of p53 and p21waf1/cip1 proteins regulating cell-cycle progression, may represent an important step in HTLV-I-induced T-cell transformation.

  12. Regulation of IFN regulatory factor 4 expression in human T cell leukemia virus-I-transformed T cells.

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    Sharma, Sonia; Grandvaux, Nathalie; Mamane, Yael; Genin, Pierre; Azimi, Nazli; Waldmann, Thomas; Hiscott, John

    2002-09-15

    IFN regulatory factor (IRF)-4 is a lymphoid/myeloid-restricted member of the IRF transcription factor family that plays an essential role in the homeostasis and function of mature lymphocytes. IRF-4 expression is tightly regulated in resting primary T cells and is transiently induced at the mRNA and protein levels after activation by Ag-mimetic stimuli such as TCR cross-linking or treatment with phorbol ester and calcium ionophore (PMA/ionomycin). However, IRF-4 is constitutively upregulated in human T cell leukemia virus type I (HTLV-I) infected T cells as a direct gene target for the HTLV-I Tax oncoprotein. In this study we demonstrate that chronic IRF-4 expression in HTLV-I-infected T lymphocytes is associated with a leukemic phenotype, and we examine the mechanisms by which continuous production of IRF-4 is achieved in HTLV-I-transformed T cells. IRF-4 expression in HTLV-1-infected cells is driven through activation of the NF-kappaB and NF-AT pathways, resulting in the binding of p50, p65, and c-Rel to the kappaB1 element and p50, c-Rel, and NF-ATp to the CD28RE element within the -617 to -209 region of the IRF-4 promoter. Furthermore, mutation of either the kappaB1 or CD28RE sites blocks Tax-mediated transactivation of the human IRF-4 promoter in T cells. These experiments constitute the first detailed analysis of human IRF-4 transcriptional regulation within the context of HTLV-I infection and transformation of CD4(+) T lymphocytes.

  13. Differences in the epigenetic regulation of MT-3 gene expression between parental and Cd+2 or As+3 transformed human urothelial cells

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    Ajjimaporn Amornpan

    2011-02-01

    Full Text Available Abstract Background Studies have shown that metallothionein 3 (MT-3 is not expressed in normal urothelium or in the UROtsa cell line, but is expressed in urothelial cancer and in tumors generated from the UROtsa cells that have been transformed by cadmium (Cd+2 or arsenite (As+3.The present study had two major goals. One, to determine if epigenetic modifications control urothelial MT-3 gene expression and if regulation is altered by malignant transformation by Cd+2 or As+3. Two, to determine if MT-3 expression might translate clinically as a biomarker for malignant urothelial cells released into the urine. Results The histone deacetylase inhibitor MS-275 induced MT-3 mRNA expression in both parental UROtsa cells and their transformed counterparts. The demethylating agent, 5-Aza-2'-deoxycytidine (5-AZC had no effect on MT-3 mRNA expression. ChIP analysis showed that metal-responsive transformation factor-1 (MTF-1 binding to metal response elements (MRE elements of the MT-3 promoter was restricted in parental UROtsa cells, but MTF-1 binding to the MREs was unrestricted in the transformed cell lines. Histone modifications at acetyl H4, trimethyl H3K4, trimethyl H3K27, and trimethyl H3K9 were compared between the parental and transformed cell lines in the presence and absence of MS-275. The pattern of histone modifications suggested that the MT-3 promoter in the Cd+2 and As+3 transformed cells has gained bivalent chromatin structure, having elements of being "transcriptionally repressed" and "transcription ready", when compared to parental cells. An analysis of MT-3 staining in urinary cytologies showed that a subset of both active and non-active patients with urothelial cancer shed positive cells in their urine, but that control patients only rarely shed MT-3 positive cells. Conclusion The MT-3 gene is silenced in non-transformed urothelial cells by a mechanism involving histone modification of the MT-3 promoter. In contrast, transformation of the

  14. Molecular transformation, gene cloning, and gene expression systems for filamentous fungi

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    Gold, Scott E.; Duick, John W.; Redman, Regina S.; Rodriguez, Rusty J.

    2001-01-01

    This chapter discusses the molecular transformation, gene cloning, and gene expression systems for filamentous fungi. Molecular transformation involves the movement of discrete amounts of DNA into cells, the expression of genes on the transported DNA, and the sustainable replication of the transforming DNA. The ability to transform fungi is dependent on the stable replication and expression of genes located on the transforming DNA. Three phenomena observed in bacteria, that is, competence, plasmids, and restriction enzymes to facilitate cloning, were responsible for the development of molecular transformation in fungi. Initial transformation success with filamentous fungi, involving the complementation of auxotrophic mutants by exposure to sheared genomic DNA or RNA from wt isolates, occurred with low transformation efficiencies. In addition, it was difficult to retrieve complementing DNA fragments and isolate genes of interest. This prompted the development of transformation vectors and methods to increase efficiencies. The physiological studies performed with fungi indicated that the cell wall could be removed to generate protoplasts. It was evident that protoplasts could be transformed with significantly greater efficiencies than walled cells.

  15. Directly Transforming PCR-Amplified DNA Fragments into Plant Cells Is a Versatile System That Facilitates the Transient Expression Assay

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    Lu, Yuming; Chen, Xi; Wu, Yuxuan; Wang, Yanping; He, Yuqing; Wu, Yan

    2013-01-01

    A circular plasmid containing a gene coding sequence has been broadly used for studying gene regulation in cells. However, to accommodate a quick screen plasmid construction and preparation can be time consuming. Here we report a PCR amplified dsDNA fragments (PCR-fragments) based transient expression system (PCR-TES) for suiting in the study of gene regulation in plant cells. Instead of transforming plasmids into plant cells, transient expression of PCR-fragments can be applicable. The transformation efficiency and expression property of PCR-fragments are comparable to transformation using plasmids. We analyzed the transformation efficiency in PCR-TES at transcription and protein levels. Our results indicate that the PCR-TES is as versatile as the conventional transformation system using plasmid DNA. Through reconstituting PYR1-mediated ABA signaling pathway in Arabidopsis mesophyll protoplasts, we were not only validating the practicality of PCR-TES but also screening potential candidates of CDPK family members which might be involved in the ABA signaling. Moreover, we determined that phosphorylation of ABF2 by CPK4 could be mediated by ABA-induced PYR1 and ABI1, demonstrating a crucial role of CDPKs in the ABA signaling. In summary, PCR-TES can be applicable to facilitate analyzing gene regulation and for the screen of putative regulatory molecules at the high throughput level in plant cells. PMID:23468926

  16. Directly transforming PCR-amplified DNA fragments into plant cells is a versatile system that facilitates the transient expression assay.

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    Yuming Lu

    Full Text Available A circular plasmid containing a gene coding sequence has been broadly used for studying gene regulation in cells. However, to accommodate a quick screen plasmid construction and preparation can be time consuming. Here we report a PCR amplified dsDNA fragments (PCR-fragments based transient expression system (PCR-TES for suiting in the study of gene regulation in plant cells. Instead of transforming plasmids into plant cells, transient expression of PCR-fragments can be applicable. The transformation efficiency and expression property of PCR-fragments are comparable to transformation using plasmids. We analyzed the transformation efficiency in PCR-TES at transcription and protein levels. Our results indicate that the PCR-TES is as versatile as the conventional transformation system using plasmid DNA. Through reconstituting PYR1-mediated ABA signaling pathway in Arabidopsis mesophyll protoplasts, we were not only validating the practicality of PCR-TES but also screening potential candidates of CDPK family members which might be involved in the ABA signaling. Moreover, we determined that phosphorylation of ABF2 by CPK4 could be mediated by ABA-induced PYR1 and ABI1, demonstrating a crucial role of CDPKs in the ABA signaling. In summary, PCR-TES can be applicable to facilitate analyzing gene regulation and for the screen of putative regulatory molecules at the high throughput level in plant cells.

  17. An Epstein-Barr virus anti-apoptotic protein constitutively expressed in transformed cells and implicated in burkitt lymphomagenesis: the Wp/BHRF1 link.

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    Gemma L Kelly

    2009-03-01

    Full Text Available Two factors contribute to Burkitt lymphoma (BL pathogenesis, a chromosomal translocation leading to c-myc oncogene deregulation and infection with Epstein-Barr virus (EBV. Although the virus has B cell growth-transforming ability, this may not relate to its role in BL since many of the transforming proteins are not expressed in the tumor. Mounting evidence supports an alternative role, whereby EBV counteracts the high apoptotic sensitivity inherent to the c-myc-driven growth program. In that regard, a subset of BLs carry virus mutants in a novel form of latent infection that provides unusually strong resistance to apoptosis. Uniquely, these virus mutants use Wp (a viral promoter normally activated early in B cell transformation and express a broader-than-usual range of latent antigens. Here, using an inducible system to express the candidate antigens, we show that this marked apoptosis resistance is mediated not by one of the extended range of EBNAs seen in Wp-restricted latency but by Wp-driven expression of the viral bcl2 homologue, BHRF1, a protein usually associated with the virus lytic cycle. Interestingly, this Wp/BHRF1 connection is not confined to Wp-restricted BLs but appears integral to normal B cell transformation by EBV. We find that the BHRF1 gene expression recently reported in newly infected B cells is temporally linked to Wp activation and the presence of W/BHRF1-spliced transcripts. Furthermore, just as Wp activity is never completely eclipsed in in vitro-transformed lines, low-level BHRF1 transcripts remain detectable in these cells long-term. Most importantly, recognition by BHRF1-specific T cells confirms that such lines continue to express the protein independently of any lytic cycle entry. This work therefore provides the first evidence that BHRF1, the EBV bcl2 homologue, is constitutively expressed as a latent protein in growth-transformed cells in vitro and, in the context of Wp-restricted BL, may contribute to virus

  18. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...... lines express TGF beta-receptors and also produce TGF beta mRNAs....

  19. Absence of PDGF-induced, PKC-independent c-fos expression in a chemically transformed C3H/10T1/2 cell clone.

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    Vassbotn, F S; Skar, R; Holmsen, H; Lillehaug, J R

    1992-09-01

    The effect of platelet-derived growth factor (PDGF) on c-fos mRNA transcription was studied in the immortalized mouse embryo fibroblast C3H/10T1/2 Cl 8 (10T1/2) cells and the chemically transformed, tumorigenic subclone C3H/10T1/2 Cl 16 (Cl 16). In the 10T1/2 cells as well as the Cl 16 subclone, the dose-dependent PDGF stimulation of c-fos mRNA synthesis was similar in both logarithmically growing and confluent cultures. c-fos mRNA was induced severalfold by 12-O-tetradecanoylphorbol-13-acetate (TPA) in both 10T1/2 and Cl 16. Down-regulation of protein kinase C (PKC) activity by TPA pretreatment inhibited PDGF-stimulated c-fos mRNA expression in Cl 16 cells but did not affect this induction in the 10T1/2 cells. This inhibition was not a general phenomenon of 3-methylcholanthrene-mediated transformation of 10T1/2 cells since experiments with another transformed 10T1/2 cell clone, C3H/10T1/2 TPA 482, gave qualitatively the same results as the 10T1/2 cells. Receptor binding experiments showed that the nontransformed and transformed cells had a comparable number of PDGF receptors, 1.3 x 10(5) and 0.7 x 10(5) receptors per cell, respectively. Furthermore, cAMP-induced c-fos expression induced by forskolin is formerly shown to be independent of PKC down-regulation. In our experiments, forskolin induced c-fos expression in both clones. However, PKC down-regulation inhibited the forskolin-induced c-fos expression in Cl 16 cells. This apparently demonstrates cross talk between PKC and PKA in the c-fos induction pathway. The present results provide evidence for an impaired mechanism for activating c-fos expression through PKC-independent, PDGF-induced signal transduction in the chemically transformed Cl 16 fibroblasts compared to that in nontransformed 10T1/2 cells.

  20. Transient HEXA expression in a transformed human fetal Tay-Sachs disease neuroglial cell line

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    Fernandes, M.J.; Hechtman, P.; Kaplan, F. [McGill Univ., Quebec (Canada)] [and others

    1994-09-01

    Tay-Sachs disease (TSD) is a severe neurodegenerative disorder characterized by the accumulation of GM{sub 2} ganglioside in the neurons of the central cortex. The recessively inherited disorder results from deficiency of hexosaminidase A (Hex A), a heterodimer of an {alpha} and {beta} subunit encoded by the HEXA and HEXB genes. Expression of HEXA mutations in COS cells has several disadvantages including high endogenous hexosaminidase activity. We report a new transient expression system with very low endogenous Hex A activity. An SV40-transformed fetal TSD neuroglial cell line was assessed for transient expression of the HEXA gene. pCMV{alpha}, a vector incorporating the cytomegalovirus promoter with the human {alpha}-subunit cDNA insert, proved to be the most efficient expression vector. Transfection of 4x10{sup 6} cells with 5-20 {mu}g of plasmid resulted in 100 to 500-fold Hex A activity (4MUGS hydrolysis) relative to mock-transfected cells. Use of pCMV{beta}-Gal as a control for transfection efficiency indicated that 10-20% of cells were transfected. Hex A specific activity increased for at least 72 h post-transfection. This new transient expression system should greatly improve the characterization of mutations in which low levels of HEXA expression result in milder clinical phenotypes and permit studies on enzymatic properties of mutant forms of Hex A. Since the cells used are of CNS origin and synthesize gangliosides, it should also be possible to study, in culture, the metabolic phenotype associated with TSD.

  1. c-Jun/AP-1 pathway-mediated cyclin D1 expression participates in low dose arsenite-induced transformation in mouse epidermal JB6 Cl41 cells

    International Nuclear Information System (INIS)

    Zhang Dongyun; Li Jingxia; Gao Jimin; Huang Chuanshu

    2009-01-01

    Arsenic is a well-documented human carcinogen associated with skin carcinogenesis. Our previous work reveals that arsenite exposure is able to induce cell transformation in mouse epidermal cell JB6 Cl41 through the activation of ERK, rather than JNK pathway. Our current studies further evaluate downstream pathway in low dose arsenite-induced cell transformation in JB6 Cl41 cells. Our results showed that treatment of cells with low dose arsenite induced activation of c-Jun/AP-1 pathway, and ectopic expression of dominant negative mutant of c-Jun (TAM67) blocked arsenite-induced transformation. Furthermore, our data indicated that cyclin D1 was an important downstream molecule involved in c-Jun/AP-1-mediated cell transformation upon low dose arsenite exposure, because inhibition of cyclin D1 expression by its specific siRNA in the JB6 Cl41 cells resulted in impairment of anchorage-independent growth of cells induced by low dose arsenite. Collectively, our results demonstrate that c-Jun/AP-1-mediated cyclin D1 expression is at least one of the key events implicated in cell transformation upon low dose arsenite exposure

  2. The studies of DNA double-strand break (DSB) rejoining and mRNA expression of repair gene XRCCs in malignant transformed cell lines of human bronchial epithelial cells generated by α-particles

    International Nuclear Information System (INIS)

    Sun Jingfen; Sui Jianli; Geng Yu; Zhou Pingkun; Wu Dechang

    2002-01-01

    Objective: To investigate the efficiency of γ-ray-induced DNA DSB rejoining and the mRNA expression of DNA repair genes in malignantly transformed cell lines of human bronchial epithelial cells generated by exposure to a-particles. Methods: Pulsed field gel electrophoresis (PFGE) was used to detect DNA. DSBs mRNA expression was analyzed by RT-PCR. Results: The residual DNA DSB damage level after 4hrs repair following 0-150 Gy of γ-irradiation in the malignantly transformed cell lines BERP35T-1 and BERP35T-4 was significantly higher than that in their parental BEP2D cells. The analysis of mRNA level revealed a 2.5-to 6.5-fold down-regulated expression of the DNA repair genes XRCC-2, XRCC-3 and Ku80 (XRCC-5) in BERP35T-1 and BERP35T-4 cells as compared with the parental BEP2D cells. In contrast, the expression of DNA-PKcs(XRCC7) was 2.4-fold up-regulated in the transformed cell line BERP35T-4, in which there was a significantly higher proportion of polyploid cells. Conclusion: This study results show that the deficiency of DNA DSB rejoining and depressed mRNA expression of DNA repair genes could be involved in the malignant transformation process of BEP2D cells induced by exposure to α-particles

  3. Induction of chemokine receptor CXCR4 expression by transforming growth factor-β1 in human basal cell carcinoma cells.

    Science.gov (United States)

    Chu, Chia-Yu; Sheen, Yi-Shuan; Cha, Shih-Ting; Hu, Yeh-Fang; Tan, Ching-Ting; Chiu, Hsien-Ching; Chang, Cheng-Chi; Chen, Min-Wei; Kuo, Min-Liang; Jee, Shiou-Hwa

    2013-11-01

    Higher CXCR4 expression enhances basal cell carcinoma (BCC) invasion and angiogenesis. The underlying mechanism of increased CXCR4 expression in invasive BCC is still not well understood. To investigate the mechanisms involved in the regulation of CXCR4 expression in invasive BCC. We used qRT-PCR, RT-PCR, Western blot, and flow cytometric analyses to examine different CXCR4 levels among the clinical samples, co-cultured BCC cells and BCC cells treated with recombinant transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). Immunohistochemical studies were used to demonstrate the correlation between TGF-β1 and CXCR4 expressions. The signal transduction pathway and transcriptional regulation were confirmed by treatments with chemical inhibitors, neutralizing antibodies, or short interfering RNAs, as well as luciferase reporter activity. Invasive BCC has higher TGF-β1 and CTGF levels compared to non-invasive BCC. Non-contact dermal fibroblasts co-culture with human BCC cells also increases the expression of CXCR4 in BCC cells. Treatment with recombinant human TGF-β1, but not CTGF, enhanced the CXCR4 levels in time- and dose-dependent manners. The protein level and surface expression of CXCR4 in human BCC cells was increased by TGF-β1 treatment. TGF-β1 was intensely expressed in the surrounding fibroblasts of invasive BCC and was positively correlated with the CXCR4 expression of BCC cells. The transcriptional regulation of CXCR4 by TGF-β1 is mediated by its binding to the TGF-β receptor II and phosphorylation of the extracellular signal-related kinase 1/2 (ERK1/2)-ETS-1 pathway. TGF-β1 induces upregulation of CXCR4 in human BCC cells by phosphorylation of ERK1/2-ETS-1 pathway. Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  4. Radiogenic cell transformation and carcinogenesis

    Science.gov (United States)

    Yang, T. C.; Georgy, K. A.; Mei, M.; Durante, M.; Craise, L. M.

    1995-01-01

    Radiation carcinogenesis is one of the major biological effects considered important in the risk assessment for space travel. Various biological model systems, including both cultured cells and animals, have been found useful for studying the carcinogenic effects of space radiations, which consist of energetic electrons, protons and heavy ions. The development of techniques for studying neoplastic cell transformation in culture has made it possible to examine the cellular and molecular mechanisms of radiation carcinogenesis. Cultured cell systems are thus complementary to animal models. Many investigators have determined the oncogenic effects of ionizing and nonionizing radiation in cultured mammalian cells. One of the cell systems used most often for radiation transformation studies is mouse embryonic cells (C3H10T1/2), which are easy to culture and give good quantitative dose-response curves. Relative biological effectiveness (RBE) for heavy ions with various energies and linear energy transfer (LET) have been obtained with this cell system. Similar RBE and LET relationship was observed by investigators for other cell systems. In addition to RBE measurements, fundamental questions on repair of sub- and potential oncogenic lesions, direct and indirect effect, primary target and lesion, the importance of cell-cell interaction and the role of oncogenes and tumor suppressor genes in radiogenic carcinogenesis have been studied, and interesting results have been found. Recently several human epithelial cell systems have been developed, and ionizing radiation have been shown to transform these cells. Oncogenic transformation of these cells, however, requires a long expression time and/or multiple radiation exposures. Limited experimental data indicate high-LET heavy ions can be more effective than low-LET radiation in inducing cell transformation. Cytogenetic and molecular analyses can be performed with cloned transformants to provide insights into basic genetic

  5. Cell of origin of transformed follicular lymphoma

    Science.gov (United States)

    Kridel, Robert; Mottok, Anja; Farinha, Pedro; Ben-Neriah, Susana; Ennishi, Daisuke; Zheng, Yvonne; Chavez, Elizabeth A.; Shulha, Hennady P.; Tan, King; Chan, Fong Chun; Boyle, Merrill; Meissner, Barbara; Telenius, Adele; Sehn, Laurie H.; Marra, Marco A.; Shah, Sohrab P.; Steidl, Christian; Connors, Joseph M.; Scott, David W.

    2015-01-01

    Follicular lymphoma (FL) is an indolent disease but transforms in 2% to 3% of patients per year into aggressive, large cell lymphoma, a critical event in the course of the disease associated with increased lymphoma-related mortality. Early transformation cannot be accurately predicted at the time of FL diagnosis and the biology of transformed FL (TFL) is poorly understood. Here, we assembled a cohort of 126 diagnostic FL specimens including 40 patients experiencing transformation (transformation for at least 5 years. In addition, we assembled an overlapping cohort of 155 TFL patients, including 114 cases for which paired samples were available, and assessed temporal changes of routinely available biomarkers, outcome after transformation, as well as molecular subtypes of TFL. We report that the expression of IRF4 is an independent predictor of early transformation (Hazard ratio, 13.3; P transformation predicts favorable prognosis. Moreover, applying the Lymph2Cx digital gene expression assay for diffuse large B-cell lymphoma (DLBCL) cell-of-origin determination to 110 patients with DLBCL-like TFL, we demonstrate that TFL is of the germinal-center B-cell–like subtype in the majority of cases (80%) but that a significant proportion of cases is of the activated B-cell–like (ABC) subtype (16%). These latter cases are commonly negative for BCL2 translocation and arise preferentially from BCL2 translocation-negative and/or IRF4-expressing FLs. Our study demonstrates the existence of molecular heterogeneity in TFL as well as its relationship to the antecedent FL. PMID:26307535

  6. Amplification of the Ect2 proto-oncogene and over-expression of Ect2 mRNA and protein in nickel compound and methylcholanthrene-transformed 10T1/2 mouse fibroblast cell lines

    International Nuclear Information System (INIS)

    Clemens, Farrah; Verma, Rini; Ramnath, Jamuna; Landolph, Joseph R.

    2005-01-01

    Occupational exposure of humans to mixtures of insoluble and soluble nickel (Ni) compounds correlates with increased incidences of lung, sinus, and pharyngeal tumors. Specific insoluble Ni compounds are carcinogenic to animals by inhalation and induce morphological and neoplastic transformation of cultured rodent cells. Our objectives were to (1) understand mechanisms of nickel ion-induced cell transformation, hence carcinogenesis and (2) develop biomarkers of nickel ion exposure and nickel ion-induced cell transformation. We isolated mRNAs from green nickel oxide (NiO), crystalline nickel monosulfide (NiS), and 3-methylcholanthrene (MCA) transformed C3H/10T1/2 Cl 8 cell lines, and determined by mRNA differential display that nine mRNA fragments were differentially expressed between Ni transformed and non-transformed 10T1/2 cell lines. Fragment R2-5 was expressed at higher steady-state levels in the transformed cell lines. R2-5 had 100% sequence identity to part of the coding region of Ect2, a mouse proto-oncogene encoding a GDP-GTP exchange factor. The 3.9-kb Ect2 transcript was expressed at 1.6- to 3.6-fold higher steady-state levels in four Ni transformed, and in two MCA-transformed, cell lines. Ect2 protein was expressed at 3.0- to 4.5-fold higher steady-state levels in Ni-transformed and in MCA-transformed cell lines. The Ect2 gene was amplified by 3.5- to 10-fold in Ni transformed, and by 2.5- to 3-fold in MCA transformed cell lines. Binding of nickel ions to enzymes of DNA synthesis likely caused amplification of the Ect2 gene. Ect2 gene amplification and over-expression of Ect2 mRNA and protein can cause microtubule disassembly and cytokinesis, contributing to induction and maintenance of morphological, anchorage-independent, and neoplastic transformation of these cell lines. Over-expression of Ect2 protein is a useful biomarker to detect exposure to nickel compounds and nickel ion-induced morphological and neoplastic cell transformation

  7. Heterogeneity in Immune Marker Expression after Acquisition of Resistance to EGFR Kinase Inhibitors: Analysis of a Case with Small Cell Lung Cancer Transformation.

    Science.gov (United States)

    Suda, Kenichi; Murakami, Isao; Yu, Hui; Kim, Jihye; Ellison, Kim; Rivard, Christopher J; Mitsudomi, Tetsuya; Hirsch, Fred R

    2017-06-01

    Expression of immune markers is of scientific interest because of their potential roles as predictive biomarkers for immunotherapy. Although the microenvironment of metastatic tumors and/or therapy-inducible histological transformation may affect the expression of these immune markers, there are few data regarding this context. A 76-year-old never-smoking female with EGFR-mutated lung adenocarcinoma (AC) acquired resistance to gefitinib. After her death, an autopsy revealed SCLC transformation and EGFR T790M secondary mutation (T790M) as mutually exclusive resistance mechanisms occurring differently in different metastases; two liver metastases (SCLC versus AC with T790M) and two lymph node metastases (SCLC versus AC with T790M) were analyzed to compare the expression status of immune markers by immunohistochemistry and by an immune oncology gene expression panel. Programmed death ligand 1 (PD-L1) protein was partially expressed in tumor cells with AC lesions (T790M) but not in tumor cells with SCLC transformation. The liver metastasis with SCLC transformation showed no stromal PD-L1 expression and scant tumor-infiltrating lymphocytes, whereas the other lesions demonstrated stromal PD-L1 staining and infiltration of CD8-positive T cells. Data generated using an immuno-oncology gene expression panel indicated a higher level of T-cell costimulatory molecules and lower expression of type I interferon-regulated genes in lesions with SCLC transformation. These data highlight the heterogeneity of expression of immune markers depending on the metastatic sites and histological transformation and indicate that the biopsy specimen from one lesion may not be representative of immune marker status for all lesions. Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

  8. Src Induces Podoplanin Expression to Promote Cell Migration*

    Science.gov (United States)

    Shen, Yongquan; Chen, Chen-Shan; Ichikawa, Hitoshi; Goldberg, Gary S.

    2010-01-01

    Nontransformed cells can force tumor cells to assume a normal morphology and phenotype by the process of contact normalization. Transformed cells must escape this process to become invasive and malignant. However, mechanisms underlying contact normalization have not been elucidated. Here, we have identified genes that are affected by contact normalization of Src-transformed cells. Tumor cells must migrate to become invasive and malignant. Src must phosphorylate the adaptor protein Cas (Crk-associated substrate) to promote tumor cell motility. We report here that Src utilizes Cas to induce podoplanin (Pdpn) expression to promote tumor cell migration. Pdpn is a membrane-bound extracellular glycoprotein that associates with endogenous ligands to promote tumor cell migration leading to cancer invasion and metastasis. In fact, Pdpn expression accounted for a major part of the increased migration seen in Src-transformed cells. Moreover, nontransformed cells suppressed Pdpn expression in adjacent Src-transformed cells. Of >39,000 genes, Pdpn was one of only 23 genes found to be induced by transforming Src activity and suppressed by contact normalization of Src-transformed cells. In addition, we found 16 genes suppressed by Src and induced by contact normalization. These genes encode growth factor receptors, adaptor proteins, and products that have not yet been annotated and may play important roles in tumor cell growth and migration. PMID:20123990

  9. Transformation of human mesenchymal cells and skin fibroblasts into hematopoietic cells.

    Directory of Open Access Journals (Sweden)

    David M Harris

    Full Text Available Patients with prolonged myelosuppression require frequent platelet and occasional granulocyte transfusions. Multi-donor transfusions induce alloimmunization, thereby increasing morbidity and mortality. Therefore, an autologous or HLA-matched allogeneic source of platelets and granulocytes is needed. To determine whether nonhematopoietic cells can be reprogrammed into hematopoietic cells, human mesenchymal stromal cells (MSCs and skin fibroblasts were incubated with the demethylating agent 5-azacytidine (Aza and the growth factors (GF granulocyte-macrophage colony-stimulating factor and stem cell factor. This treatment transformed MSCs to round, non-adherent cells expressing T-, B-, myeloid-, or stem/progenitor-cell markers. The transformed cells engrafted as hematopoietic cells in bone marrow of immunodeficient mice. DNA methylation and mRNA array analysis suggested that Aza and GF treatment demethylated and activated HOXB genes. Indeed, transfection of MSCs or skin fibroblasts with HOXB4, HOXB5, and HOXB2 genes transformed them into hematopoietic cells. Further studies are needed to determine whether transformed MSCs or skin fibroblasts are suitable for therapy.

  10. Characterization of transformation related genes in oral cancer cells.

    Science.gov (United States)

    Chang, D D; Park, N H; Denny, C T; Nelson, S F; Pe, M

    1998-04-16

    A cDNA representational difference analysis (cDNA-RDA) and an arrayed filter technique were used to characterize transformation-related genes in oral cancer. From an initial comparison of normal oral epithelial cells and a human papilloma virus (HPV)-immortalized oral epithelial cell line, we obtained 384 differentially expressed gene fragments and arrayed them on a filter. Two hundred and twelve redundant clones were identified by three rounds of back hybridization. Sequence analysis of the remaining clones revealed 99 unique clones corresponding to 69 genes. The expression of these transformation related gene fragments in three nontumorigenic HPV-immortalized oral epithelial cell lines and three oral cancer cell lines were simultaneously monitored using a cDNA array hybridization. Although there was a considerable cell line-to-cell line variability in the expression of these clones, a reliable prediction of their expression could be made from the cDNA array hybridization. Our study demonstrates the utility of combining cDNA-RDA and arrayed filters in high-throughput gene expression difference analysis. The differentially expressed genes identified in this study should be informative in studying oral epithelial cell carcinogenesis.

  11. The quest for targets executing MYC-dependent cell transformation

    Directory of Open Access Journals (Sweden)

    Markus eHartl

    2016-06-01

    Full Text Available MYC represents a transcription factor with oncogenic potential converting multiple cellular signals into a broad transcriptional response, thereby controlling the expression of numerous protein-coding and non-coding RNAs important for cell proliferation, metabolism, differentiation, and apoptosis. Constitutive activation of MYC leads to neoplastic cell transformation, and deregulated MYC alleles are frequently observed in many human cancer cell types. Multiple approaches have been performed to isolate genes differentially expressed in cells containing aberrantly activated MYC proteins leading to the identification of thousands of putative targets. Functional analyses of genes differentially expressed in MYC-transformed cells had revealed that so far more than forty upregulated or downregulated MYC targets are actively involved in cell transformation or tumorigenesis. However, for determination which of the known, or yet unidentified targets are responsible for processing the oncogenic MYC program, further systematic and selective approaches are required. The search for critical targets in MYC-dependent tumor cells is exacerbated by the fact that during tumor development, cancer cells progressively evolve in a multistep process thereby acquiring their characteristic features in an additive manner. Functional expression cloning, combinatorial gene expression and appropriate in vivo tests could represent adequate tools for dissecting the complex scenario of MYC-specified cell transformation. In this context, the central goal is to identify a minimal set of targets that suffices to phenocopy oncogenic MYC. Recently developed genomic editing tools could be employed to confirm the requirement of crucial transformation-associated targets.Knowledge about essential MYC regulated genes is beneficial to expedite the development of specific inhibitors to interfere with growth and viability of human tumor cells in which MYC is aberrantly activated

  12. Expression of the small T antigen of Lymphotropic Papovavirus is sufficient to transform primary mouse embryo fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Tushar; Robles, Maria Teresa Sáenz [Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Schowalter, Rachel M.; Buck, Christopher B. [Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892-4263 (United States); Pipas, James M., E-mail: pipas@pitt.edu [Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260 (United States)

    2016-01-15

    Polyomaviruses induce cell proliferation and transformation through different oncoproteins encoded within the early region (ER): large T antigen (LT), small T antigen (sT) and, in some cases, additional components. Each virus utilizes different mechanisms to achieve transformation. For instance, the LTs of Simian virus 40 (SV40), BK and/or JC virus can induce transformation; but Merkel Cell Polyomavirus (MCPyV) requires expression of sT. Lymphotropic Papovavirus (LPV) is closely related to Human Polyomavirus 9 (HuPyV9) and, under similar conditions, mice expressing LPV.ER exhibit higher rates of tumor formation than mice expressing SV40.ER. We have investigated the contributions of individual LPV.ER components to cell transformation. In contrast to SV40, LPV.ER transforms mouse embryonic fibroblasts (MEFs), but expression of LPV LT is insufficient to transform MEFs. Furthermore, LPV sT induces immortalization and transformation of MEFs. Thus, in the case of LPV, sT is the main mediator of oncogenesis. - Highlights: • Characterization of early region products from the Lymphotropic Polyomavirus (LPV). • On its own, sT immortalizes and transforms mouse primary cells, and is able to block p53 activation. • Combined LT and sT expression induces a greater rate of proliferation than either LT or sT alone.

  13. Differential gene expression and clonal selection during cellular transformation induced by adhesion deprivation

    Directory of Open Access Journals (Sweden)

    Kumar Mahesh J

    2010-12-01

    Full Text Available Abstract Background Anchorage independent growth is an important hallmark of oncogenic transformation. Previous studies have shown that when adhesion dependent fibroblasts were prevented from adhering to a substrate they underwent anoikis. In the present study we have demonstrated how anoikis resistant cells gain the transformation related properties with sequential selection of genes. We have proposed this process as a model system for selection of transformed cells from normal cells. Results This report demonstrates that some fibroblasts can survive during late stages of anoikis, at which time they exhibit transformation-associated properties such as in vitro colony formation in soft agar and in vivo subcutaneous tumour formation in nude mice. Cytogenetic characterisation of these cells revealed that they contained a t (2; 2 derivative chromosome and they have a selective survival advantage in non adherent conditions. Gene expression profile indicated that these cells over expressed genes related to hypoxia, glycolysis and tumor suppression/metastasis which could be helpful in their retaining a transformed phenotype. Conclusion Our results reveal some new links between anoikis and cell transformation and they provide a reproducible model system which can potentially be useful to study multistage cancer and to identify new targets for drug development.

  14. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax

    International Nuclear Information System (INIS)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-01-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion–induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo

  15. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax.

    Science.gov (United States)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-12-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion-induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  16. Biochemical characterization of cells transformed via transfection by feline sarcoma virus proviral DNA.

    OpenAIRE

    Rosenberg, Z F; Sahagan, B G; Snyder, H W; Worley, M B; Essex, M; Haseltine, W A

    1981-01-01

    Murine fibroblasts transformed by transfection with DNA from mink cells infected with the Snyder-Theilen strain of feline sarcoma virus and subgroup B feline leukemia virus were analyzed for the presence of integrated proviral DNA and the expression of feline leukemia virus- and feline sarcoma virus-specific proteins. The transformed murine cells harbored at least one intact feline sarcoma virus provirus, but did not contain feline leukemia virus provirus. The transformed murine cells express...

  17. Two-dimensional electrophoretic analysis of transformation-sensitive polypeptides during chemically, spontaneously, and oncogene-induced transformation of rat liver epithelial cells

    DEFF Research Database (Denmark)

    Wirth, P J; Luo, L D; Fujimoto, Y

    1992-01-01

    ; AFB), spontaneously, and oncogene (v-Ha-ras, v-raf, and v-myc/v-raf)-induced transformation of RLE cells. Two-dimensional mapping of [35S]methionine-labeled whole cell lysate, cell-free in vitro translation products and [32P]orthophosphate-labeled polypeptides revealed subsets of polypeptides specific...... for each transformation modality. A search of the RLE protein database indicated the specific subcellular location for the majority of these transformation-sensitive proteins. Significant alterations in the expression of the extracellular matrix protein, fibronectin, as well as tropomyosin......- and intermediate filament-related polypeptides (vimentin, beta-tubulin, the cytokeratins, and actin) were observed among the various transformant cell lines. Immunoprecipitation and Western immunoblot analysis of tropomyosin expression in four individual AFB-, as well as four spontaneously induced, and each...

  18. Cell-to-cell transformation in Escherichia coli: a novel type of natural transformation involving cell-derived DNA and a putative promoting pheromone.

    Directory of Open Access Journals (Sweden)

    Rika Etchuuya

    Full Text Available Escherichia coli is not assumed to be naturally transformable. However, several recent reports have shown that E. coli can express modest genetic competence in certain conditions that may arise in its environment. We have shown previously that spontaneous lateral transfer of non-conjugative plasmids occurs in a colony biofilm of mixed E. coli strains (a set of a donor strain harbouring a plasmid and a plasmid-free recipient strain. In this study, with high-frequency combinations of strains and a plasmid, we constructed the same lateral plasmid transfer system in liquid culture. Using this system, we demonstrated that this lateral plasmid transfer was DNase-sensitive, indicating that it is a kind of transformation in which DNase-accessible extracellular naked DNA is essential. However, this transformation did not occur with purified plasmid DNA and required a direct supply of plasmid from co-existing donor cells. Based on this feature, we have termed this transformation type as 'cell-to-cell transformation'. Analyses using medium conditioned with the high-frequency strain revealed that this strain released a certain factor(s that promoted cell-to-cell transformation and arrested growth of the other strains. This factor is heat-labile and protease-sensitive, and its roughly estimated molecular mass was between ∼9 kDa and ∼30 kDa, indicating that it is a polypeptide factor. Interestingly, this factor was effective even when the conditioned medium was diluted 10(-5-10(-6, suggesting that it acts like a pheromone with high bioactivity. Based on these results, we propose that cell-to-cell transformation is a novel natural transformation mechanism in E. coli that requires cell-derived DNA and is promoted by a peptide pheromone. This is the first evidence that suggests the existence of a peptide pheromone-regulated transformation mechanism in E. coli and in Gram-negative bacteria.

  19. Defective repair of UV-damaged DNA in human tumor and SV40-transformed human cells but not in adenovirus-transformed human cells

    International Nuclear Information System (INIS)

    Rainbow, A.J.

    1989-01-01

    The DNA repair capacities of five human tumor cell lines, one SV40-transformed human cell line and one adenovirus-transformed human cell line were compared with that of normal human fibroblasts using a sensitive host cell reactivation (HCR) technique. Unirradiated and UV-irradiated suspensions of adenovirus type 2 (Ad 2) were assayed for their ability to form viral structural antigens (Vag) in the various cell types using immunofluorescent staining. The survival of Vag formation for UV-irradiated Ad 2 was significantly reduced in all the human tumor cell lines and the SV40-transformed human line compared to the normal human fibroblasts, but was apparently normal in the adenovirus-transformed human cells. D 0 values for the UV survival of Ad 2 Vag synthesis in the tumor and virally transformed lines expressed as a percentage of that obtained on normal fibroblast strains were used as a measure of DNA repair capacity. Percent HCR values ranged from 26 to 53% in the tumor cells. These results indicate a deficiency in the repair of UV-induced DNA damage associated with human tumorigenesis and the transformation of human cells by SV40 but not the transformation of human cells by adenovirus. (author)

  20. P01.29 Mutant (R132H) IDH1-driven cellular transformation makes cells dependent on continued wild type IDH1 expression in a model of in vitro gliomagenesis

    Science.gov (United States)

    Johannessen, T.; Mukherjee, J.; Wood, M.; Viswanath, P.; Ohba, S.; Ronen, S.; Berkvig, R.; Pieper, R.

    2017-01-01

    Abstract Introduction: Missense R132H mutations in the active site of isocitrate dehydrogenase 1 (IDH1) biologically and diagnostically distinguish low-grade gliomas and secondary glioblastomas from primary glioblastomas. IDH1 mutations lead to the formation of the oncometabolite 2-hydroxyglutarate (2-HG) from the reduction of α-ketoglutarate (α-KG), which in turn facilitates tumorigenesis by modifying DNA and histone methylation as well blocking differentiation processes. We recently showed (Mol Cancer Res 14: 976–983, 2016) that although mutant IDH1 expression in hTERT-immortalized, p53/pRb-deficient astrocytes can drive cellular transformation and gliomagenesis, selective pharmacologic inhibition and elimination of 2-HG by the mutant IDH1 inhibitor AGI-5198 has little effect on the growth or clonagenicity of these transformed cells. To address the possible role of WT IDH1 in the growth of mutant IDH-driven tumor cells, we used a slightly different gliomagenesis model in which the transformation of TERT-deficient, p53/pRb-deficient astrocytes (pre-crisis cells) occurs only after prolonged expression of mutant IDH and passage through cellular crisis (post-crisis cells, Cancer Res 76:6680–6689, 2016). METHODS AND MATERIALS: Using this system we introduced AGI-5198, or siRNA targeting both WT and mutant forms of IDH1 into p53/pRb-deficient, mutant IDH1-expressing human astrocytes prior to or following their transformation, and compared the effects on cell growth and clonagenicity. Results: AGI-5198 exposure decreased levels of 2HG by greater than 90%, and as previously reported had no effect on the growth of either the pre-or post-crisis cell populations. A one-day exposure to a pan IDH1 siRNA resulted in a similar, prolonged (greater than 6 day), 80% inhibition of both WT and mutant IDH1 protein levels and 2HG in both cell groups. While the growth of the mutant IDH-expressing, non-transformed cells was similar to that of scramble siRNA controls, the growth

  1. B cell-derived transforming growth factor-β1 expression limits the induction phase of autoimmune neuroinflammation.

    Science.gov (United States)

    Bjarnadóttir, Kristbjörg; Benkhoucha, Mahdia; Merkler, Doron; Weber, Martin S; Payne, Natalie L; Bernard, Claude C A; Molnarfi, Nicolas; Lalive, Patrice H

    2016-10-06

    Studies in experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), have shown that regulatory B cells modulate the course of the disease via the production of suppressive cytokines. While data indicate a role for transforming growth factor (TGF)-β1 expression in regulatory B cell functions, this mechanism has not yet been tested in autoimmune neuroinflammation. Transgenic mice deficient for TGF-β1 expression in B cells (B-TGF-β1 -/- ) were tested in EAE induced by recombinant mouse myelin oligodendrocyte glycoprotein (rmMOG). In this model, B-TGF-β1 -/- mice showed an earlier onset of neurologic impairment compared to their littermate controls. Exacerbated EAE susceptibility in B-TGF-β1 -/- mice was associated with augmented CNS T helper (Th)1/17 responses. Moreover, selective B cell TGF-β1-deficiency increased the frequencies and activation of myeloid dendritic cells, potent professional antigen-presenting cells (APCs), suggesting that B cell-derived TGF-β1 can constrain Th1/17 responses through inhibition of APC activity. Collectively our data suggest that B cells can down-regulate the function of APCs, and in turn encephalitogenic Th1/17 responses, via TGF-β1, findings that may be relevant to B cell-targeted therapies.

  2. Estrogen Drives Cellular Transformation and Mutagenesis in Cells Expressing the Breast Cancer-Associated R438W DNA Polymerase Lambda Protein.

    Science.gov (United States)

    Nemec, Antonia A; Bush, Korie B; Towle-Weicksel, Jamie B; Taylor, B Frazier; Schulz, Vincent; Weidhaas, Joanne B; Tuck, David P; Sweasy, Joann B

    2016-11-01

    Repair of DNA damage is critical for maintaining the genomic integrity of cells. DNA polymerase lambda (POLL/Pol λ) is suggested to function in base excision repair (BER) and nonhomologous end-joining (NHEJ), and is likely to play a role in damage tolerance at the replication fork. Here, using next-generation sequencing, it was discovered that the POLL rs3730477 single-nucleotide polymorphism (SNP) encoding R438W Pol λ was significantly enriched in the germlines of breast cancer patients. Expression of R438W Pol λ in human breast epithelial cells induces cellular transformation and chromosomal aberrations. The role of estrogen was assessed as it is commonly used in hormone replacement therapies and is a known breast cancer risk factor. Interestingly, the combination of estrogen treatment and the expression of the R438W Pol λ SNP drastically accelerated the rate of transformation. Estrogen exposure produces 8-oxoguanine lesions that persist in cells expressing R438W Pol λ compared with wild-type (WT) Pol λ-expressing cells. Unlike WT Pol λ, which performs error-free bypass of 8-oxoguanine lesions, expression of R438W Pol λ leads to an increase in mutagenesis and replicative stress in cells treated with estrogen. Together, these data suggest that individuals who carry the rs3730477 POLL germline variant have an increased risk of estrogen-associated breast cancer. The Pol λ R438W mutation can serve as a biomarker to predict cancer risk and implicates that treatment with estrogen in individuals with this mutation may further increase their risk of breast cancer. Mol Cancer Res; 14(11); 1068-77. ©2016 AACR. ©2016 American Association for Cancer Research.

  3. MicroRNA-26a-mediated regulation of interleukin-2 expression in transformed avian lymphocyte lines

    Directory of Open Access Journals (Sweden)

    Smith Lorraine P

    2010-05-01

    Full Text Available Abstract Background Micro(miRNAs are a class of small non-coding RNAs that play critical roles in the induction of various cancers, including lymphomas induced by oncogenic viruses. While some of the miRNAs are oncogenic, miRNAs such as miR-26a are consistently downregulated in a number of cancers, demonstrating their potential tumor suppressor functions. Global miRNA expression profiles of a number of virus-transformed avian lymphoma cell lines have shown downregulation of gga-miR-26a expression, irrespective of molecular mechanisms of transformation or the viral aetiology. The neoplastic transformation of lymphocytes by many viruses accompanies high levels of proliferative responses, mostly mediated through cytokines such as IL-2. Chicken IL-2 can modulate T-cell proliferation and cytotoxicity in vitro and in vivo and dysregulation of IL-2 expression is observed in diseases such as leukaemia. Results The expression levels of gga-miR-26a in chicken lymphoma cells transformed by 3 distinct avian oncogenic viruses, viz Marek's disease virus (MDV, avian leukosis virus (ALV and Reticuloendotheliosis virus (REV were consistently downregulated compared to the levels in the normal lymphocytes. This downregulation of miR-26a regardless of the viral etiology and molecular mechanisms of transformation was consistent with the tumor suppressor role of this miRNA. Notwithstanding this well-established role in cancer, we demonstrate the additional role of this miRNA in directly targeting chicken IL-2 through reporter and biochemical assays. The downregulation of miR-26a can relieve the suppressive effect of this miRNA on IL-2 expression. Conclusions We show that miR-26a is globally downregulated in a number of avian lymphoma cells irrespective of the mechanisms of transformation, reiterating the highly conserved tumor suppressor function of this miRNA. However, with the potential for directly targeting chicken IL-2, the downregulation of miR-26a in these

  4. Rat embryo cells immortalized with transfected oncogenes are transformed by gamma irradiation.

    Science.gov (United States)

    Endlich, B; Salavati, R; Sullivan, T; Ling, C C

    1992-12-01

    Cesium-137 gamma rays were used to transform rat embryo cells (REC) which were first transfected with activated c-myc or c-Ha-ras oncogenes to produce immortal cell lines (REC:myc and REC:ras). When exposed to 6 Gy of 137Cs gamma rays, some cells became morphologically transformed with focus formation frequencies of approximately 3 x 10(-4) for REC:myc and approximately 1 x 10(-4) for REC:ras, respectively. Cells isolated from foci of gamma-ray-transformed REC:myc (REC:myc:gamma) formed anchorage-independent colonies and were tumorigenic in nude mice, but foci from gamma-ray-transformed REC:ras (REC:ras:gamma) did not exhibit either of these criteria of transformation. Similar to the results with gamma irradiation, we observed a sequence-dependent phenomenon when myc and ras were transfected into REC, one at a time. REC immortalized by ras transfection were not converted to a tumorigenic phenotype by secondary transfection with myc, but REC transfected with myc were very susceptible to transformation by subsequent ras transfection. This suggests that myc-immortalized cells are more permissive to transformation via secondary treatments. In sequentially transfected REC, myc expression was high whether it was transfected first or second, whereas ras expression was highest when the ras gene was transfected secondarily into myc-containing REC. Molecular analysis of REC:ras:gamma transformants showed no alterations in structure of the transfected ras or of the endogenous ras, myc, p53, or fos genes. The expression of ras and p53 was increased in some isolates of REC:ras:gamma, but myc and fos expression were not affected. Similarly, REC:myc:gamma transformants did not demonstrate rearrangement or amplification of the transfected or the endogenous myc genes, or of the potentially cooperating Ha-, Ki-, or N-ras genes. Northern hybridization analysis revealed increased expression of N-ras in two isolates, REC:myc:gamma 33 and gamma 41, but no alterations in the expression

  5. Mechanisms of chemical modification of neoplastic cell transformation by ionizing radiation

    International Nuclear Information System (INIS)

    Yang, T.C.; Tobias, C.A.

    1985-01-01

    During space travel, astronauts will be continuously exposed to ionizing radiation; therefore, it is necessary to minimize the radiation damage by all possible means. The authors' studies show that DMSO (when present during irradiation) can protect cells from being killed and transformed by X rays and that low concentration of DMSO can reduce the transformation frequency significantly when it is applied to cells, even many days after irradiation. The process of neoplastic cell transformation is a complicated one and includes at least two different stages: induction and expression. DMSO apparently can modify the radiation damage during both stages. There are several possible mechanisms for the DMSO effect: (1) changing the cell membrane structure and properties; (2) inducing cell differentiation by acting on DNA; and (3) scavanging free radicals in the cell. Recent studies with various chemical agents, e.g., 5-azacytidine, dexamethane, rhodamin-123, etc., indicate that the induction of cell differentiation by acting on DNA may be an important mechanism for the suppression of expression of neoplastic cell transformation by DMSO

  6. Analysis of plasma membrane Ca(2+)-ATPase expression in control and SV40-transformed human fibroblasts.

    Science.gov (United States)

    Reisner, P D; Brandt, P C; Vanaman, T C

    1997-01-01

    It has been long known that neoplastic transformation is accompanied by a lowered requirement for extracellular Ca2+ for growth. The studies presented here demonstrate that human fibroblastic cell lines produce the two commonly found 'housekeeping' isoforms of the plasma membrane Ca(2+)-ATPase (PMCA), PMCA1b and 4b, and at the expression of both is demonstrably lower in cell lines neoplastically transformed by SV40 than in the corresponding parental cell lines. Western blot analyses of lysates from control (GM00037) and SV40-transformed (GM00637) skin fibroblasts revealed a 138 kDa PMCA whose level was significantly lower in the SV40-transformed cells relative to either total cellular protein or alpha-tubulin. Similar analyses of plasma membrane preparations from control WI-38) and SV40-transformed (WI-38VA13) lung fibroblasts revealed 3-4-fold lower levels of PMCA in the SV40-transformed cells. Competitive ELISAs performed on detergent solubilized plasma membrane preparations indicated at least 3-4-fold lower levels of PMCA in the SV40-transformed cell lines compared to controls. Reverse transcriptase coupled-PCR analyses showed that PMCA1b and PMCA4b were the only isoforms expressed in all four cell lines. The PMCA4b mRNA level detected by Northern analysis also was substantially lower in SV40 transformed skin fibroblasts than in non-transformed fibroblasts. Quantitative RT-PCR analyses showed levels of PMCA1b and 4b mRNAs to be 5 and 10-fold lower, respectively, in GM00637 than in GM00037 when the levels of PCR products were normalized to glyceraldehyde-3-phosphate dehydrogenase (G3PDH) mRNA. These results demonstrate that the expression of these distinct PMCA genes is substantially lower in SV40 transformed human skin and lung fibroblasts and may be coordinately regulated in these cells.

  7. Modulating factors in the expression of radiation-induced oncogenic transformation

    International Nuclear Information System (INIS)

    Hall, E.J.; Hei, T.K.

    1990-01-01

    Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, selenium, vitamin E, and 5-aminobenzamide that inhibit the expression of transformation. Densely ionizing α-particles, similar to those emitted by radon daughters, are highly effective in inducing transformations and appear to interact in a supra-additive fashion with asbestos fibers. The activation of a known dominant oncogene has not yet been demonstrated in radiation-induced oncogenic transformation. The most likely mechanism for radiation activation of an oncogene would be via the production of a chromosomal translocation. Radiation also efficiently induces deletions and may thus lead to the loss of a suppressor gene

  8. Down-regulation of Rab5 decreases characteristics associated with maintenance of cell transformation

    International Nuclear Information System (INIS)

    Silva, Patricio; Soto, Nicolás; Díaz, Jorge; Mendoza, Pablo; Díaz, Natalia; Quest, Andrew F.G.; Torres, Vicente A.

    2015-01-01

    The early endosomal protein Rab5 is highly expressed in tumor samples, although a causal relationship between Rab5 expression and cell transformation has not been established. Here, we report the functional effects of targeting endogenous Rab5 with specific shRNA sequences in different tumor cell lines. Rab5 down-regulation in B16-F10 cells decreased tumor formation by subcutaneous injection into C57/BL6 mice. Accordingly, Rab5 targeting in B16-F10 and A549, but not MDA-MB-231 cells was followed by decreased cell proliferation, increased apoptosis and decreased anchorage-independent growth. These findings suggest that Rab5 expression is required to maintain characteristics associated with cell transformation. - Highlights: • Rab5 is important to the maintenance of cell transformation characteristics. • Down-regulation of Rab5 decreases cell proliferation and increases apoptosis in different cancer cells. • Rab5 is required for anchorage-independent growth and tumorigenicity in-vivo

  9. Cell-surface associated with transformation of human hepatocytes to the malignant phenotype

    International Nuclear Information System (INIS)

    Wilson, B.; Ozturk, M.; Takahashi, H.; Motte, P.; Kew, M.; Isselbacher, K.J.; Wands, J.R.

    1988-01-01

    Hepatocellular carcinoma is one of the leading causes of cancer death in the world. To understand the cellular changes associated with transformation of hepatocytes to the malignant state, the authors have made several libraries of monoclonal antibodies against the hepatocellular carcinoma cell line FOCUS and have found six antibodies (AF-20, SF-25, SF-31, SF-90, XF-4, and XF-8) that recognize antigens expressed at consistently higher levels on hepatoma cells. They have studied malignant and nontransformed liver tissue from the same individual by using direct 125 I-labeled antibody binding and immunoperoxidase staining techniques. For each of these antibodies, they found striking increases in antigen expression on the transformed tissues. These antigens were found to be expressed throughout the tumor and on distant metastases, with little, if any, expression on the nontransformed adjacent liver. These antibodies demonstrate that hepatic transformation may be accompanied by stereotyped and predictable antigenic changes. The uniformity of such antigenic changes suggests an association between these cell-surface alterations and the malignant transformation process

  10. SATB2 expression increased anchorage-independent growth and cell migration in human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Feng; Jordan, Ashley; Kluz, Thomas [Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987 (United States); Shen, Steven [Center for Health Informatics and Bioinformatics, New York University Langone Medical Center, New York, NY 10016 (United States); Sun, Hong; Cartularo, Laura A. [Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987 (United States); Costa, Max, E-mail: Max.Costa@nyumc.org [Department of Environmental Medicine, New York University School of Medicine, 57 Old Forge Road, Tuxedo, NY 10987 (United States)

    2016-02-15

    The special AT-rich sequence-binding protein 2 (SATB2) is a protein that binds to the nuclear matrix attachment region of the cell and regulates gene expression by altering chromatin structure. In our previous study, we reported that SATB2 gene expression was induced in human bronchial epithelial BEAS-2B cells transformed by arsenic, chromium, nickel and vanadium. In this study, we show that ectopic expression of SATB2 in the normal human bronchial epithelial cell-line BEAS-2B increased anchorage-independent growth and cell migration, meanwhile, shRNA-mediated knockdown of SATB2 significantly decreased anchorage-independent growth in Ni transformed BEAS-2B cells. RNA sequencing analyses of SATB2 regulated genes revealed the enrichment of those involved in cytoskeleton, cell adhesion and cell-movement pathways. Our evidence supports the hypothesis that SATB2 plays an important role in BEAS-2B cell transformation. - Highlights: • We performed SATB2 overexpression in the BEAS-2B cell line. • We performed SATB2 knockdown in a Ni transformed BEAS-2B cell line. • SATB2 induced anchorage-independent growth and increased cell migration. • SATB2 knockdown significantly decreased anchorage-independent growth. • We identified alterations in gene involved in cytoskeleton, cell adhesion.

  11. SATB2 expression increased anchorage-independent growth and cell migration in human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Wu, Feng; Jordan, Ashley; Kluz, Thomas; Shen, Steven; Sun, Hong; Cartularo, Laura A.; Costa, Max

    2016-01-01

    The special AT-rich sequence-binding protein 2 (SATB2) is a protein that binds to the nuclear matrix attachment region of the cell and regulates gene expression by altering chromatin structure. In our previous study, we reported that SATB2 gene expression was induced in human bronchial epithelial BEAS-2B cells transformed by arsenic, chromium, nickel and vanadium. In this study, we show that ectopic expression of SATB2 in the normal human bronchial epithelial cell-line BEAS-2B increased anchorage-independent growth and cell migration, meanwhile, shRNA-mediated knockdown of SATB2 significantly decreased anchorage-independent growth in Ni transformed BEAS-2B cells. RNA sequencing analyses of SATB2 regulated genes revealed the enrichment of those involved in cytoskeleton, cell adhesion and cell-movement pathways. Our evidence supports the hypothesis that SATB2 plays an important role in BEAS-2B cell transformation. - Highlights: • We performed SATB2 overexpression in the BEAS-2B cell line. • We performed SATB2 knockdown in a Ni transformed BEAS-2B cell line. • SATB2 induced anchorage-independent growth and increased cell migration. • SATB2 knockdown significantly decreased anchorage-independent growth. • We identified alterations in gene involved in cytoskeleton, cell adhesion.

  12. Expression of the RAE-1 Family of Stimulatory NK-Cell Ligands Requires Activation of the PI3K Pathway during Viral Infection and Transformation

    Science.gov (United States)

    Tokuyama, Maria; Lorin, Clarisse; Delebecque, Frederic; Jung, Heiyoun; Raulet, David H.; Coscoy, Laurent

    2011-01-01

    Natural killer (NK) cells are lymphocytes that play a major role in the elimination of virally-infected cells and tumor cells. NK cells recognize and target abnormal cells through activation of stimulatory receptors such as NKG2D. NKG2D ligands are self-proteins, which are absent or expressed at low levels on healthy cells but are induced upon cellular stress, transformation, or viral infection. The exact molecular mechanisms driving expression of these ligands remain poorly understood. Here we show that murine cytomegalovirus (MCMV) infection activates the phosphatidylinositol-3-kinase (PI3K) pathway and that this activation is required for the induction of the RAE-1 family of mouse NKG2D ligands. Among the multiple PI3K catalytic subunits, inhibition of the p110α catalytic subunit blocks this induction. Similarly, inhibition of p110α PI3K reduces cell surface expression of RAE-1 on transformed cells. Many viruses manipulate the PI3K pathway, and tumors frequently mutate the p110α oncogene. Thus, our findings suggest that dysregulation of the PI3K pathway is an important signal to induce expression of RAE-1, and this may represent a commonality among various types of cellular stresses that result in the induction of NKG2D ligands. PMID:21966273

  13. Transforming growth factor-β inhibits CCAAT/enhancer-binding protein expression and PPARγ activity in unloaded bone marrow stromal cells

    International Nuclear Information System (INIS)

    Ahdjoudj, S.; Kaabeche, K.; Holy, X.; Fromigue, O.; Modrowski, D.; Zerath, E.; Marie, P.J.

    2005-01-01

    The molecular mechanisms regulating the adipogenic differentiation of bone marrow stromal cells in vivo remain largely unknown. In this study, we investigated the regulatory effects of transforming growth factor beta-2 (TGF-β2) on transcription factors involved in adipogenic differentiation induced by hind limb suspension in rat bone marrow stromal cells in vivo. Time course real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis of gene expression showed that skeletal unloading progressively increases the expression of CCAAT/enhancer-binding protein (C/EBP)α and C/EBPβ α at 5 days in bone marrow stromal cells resulting in increased peroxisome proliferator-activated receptor γ (PPARγ2) transcripts at 7 days. TGF-β2 administration in unloaded rats corrected the rise in C/EBPα and C/EBPβ transcripts induced by unloading in bone marrow stromal cells. This resulted in inhibition of PPARγ2 expression that was associated with increased Runx2 expression. Additionally, the inhibition of C/EBPα and C/EBPβ expression by TGF-β2 was associated with increased PPARγ serine phosphorylation in bone marrow stromal cells, a mechanism that inhibits PPARγ transactivating activity. The sequential inhibitory effect of TGF-β2 on C/EBPα, C/EBPβ, and PPARγ2 resulted in reduced LPL expression and abolition of bone marrow stromal cell adipogenic differentiation, which contributed to prevent bone loss induced by skeletal unloading. We conclude that TGF-β2 inhibits the excessive adipogenic differentiation of bone marrow stromal cells induced by skeletal unloading by inhibiting C/EBPα, C/EBPβ, and PPARγ expression and activity, which provides a sequential mechanism by which TGF-β2 regulates adipogenic differentiation of bone marrow stromal cells in vivo

  14. Distinctive transforming genes in x-ray-transformed mammalian cells

    International Nuclear Information System (INIS)

    Borek, C.; Ong, A.; Mason, H.

    1987-01-01

    DNAs from hamster embryo cells and mouse C3H/10T1/2 cells transformed in vitro by x-irradiation into malignant cells transmit the radiation transformation phenotype by producing transformed colonies (transfectants) in two mouse recipient lines, the NIH 3T3 and C3H/101/2 cells, and in a rat cell line, the Rat-2 cells. DNAs from unirradiated cells or irradiated and visibly untransformed cells do not produce transformed colonies. The transfectant grow in agar and form tumors in nude mice. Treatment of the DNAs with restriction endonucleases prior to transfection indicates that the same transforming gene (oncogene) is present in each of the transformed mouse cells and is the same in each of the transformed hamster cells. Southern blot analysis of 3T3 or Rat-2 transfectants carrying oncogenes from radiation-transformed C3H/10T1/2 or hamster cells indicates that the oncogenes responsible for the transformation of 3T3 cells are not the Ki-ras, Ha-ras, N-ras genes, nor are they neu, trk, raf, abl, or fms. The work demonstrates that DNAs from mammalian cells transformed into malignancy by direct exposure in vitro to radiation contain genetic sequences with detectable transforming activity in three recipient cell lines. The results provide evidence that DNA is the target of radiation carcinogenesis induced at a cellular level in vitro. The experiments indicate that malignant radiogenic transformation in vitro of hamster embryo and mouse C3H/10T1/2 cells involves the activation of unique non-ras transforming genes, which heretofore have not been described

  15. The relevance of cell transformation to carcinogenesis in vivo

    International Nuclear Information System (INIS)

    Little, J.B.

    1989-01-01

    Despite the caveats concerning rodent as opposed to human cell transformation systems, the author concludes there are several areas in which cell transformation studies with rodent cells have shown clear relevance to carcinogenesis in vivo, especially studies of carcinogenic effects of high LET radiation, particularly dependence on dose rate. In vitro studies firmly established the generality of promotion by phorbol esters tumour promotors. Initial studies on suppression of transformation, notably by protease inhibitors, has led to the confirmation of this phenomenon in in vivo carcinogenesis; development of inhibitor preparations from natural sources suitable for long-term supplementation in human diet, is under investigation. The potential importance of these modifiers is further emphasized by mechanistic studies suggesting that radiation may initiate a large fraction of exposed cell population, and expression of transformation may be controlled to a large extent by environmental conditions including the presence of promoting or suppressing agents. Finally, cell transformation systems offer the opportunity for mechanistic studies of the initial stages of carcinogenesis. Provocative results have arisen in several areas consistent with findings in experimental animals. (author)

  16. MYC expression and translocation analyses in low-grade and transformed follicular lymphoma

    NARCIS (Netherlands)

    Aukema, Sietse M.; van Pel, Roel; Nagel, Inga; Bens, Susanne; Siebert, Reiner; Rosati, Stefano; van den Berg, Eva; Bosga-Bouwer, Anneke G.; Kibbelaar, Robby E.; Hoogendoorn, Mels; van Imhoff, Gustaaf W.; Kluin-Nelemans, Hanneke C.; Kluin, Philip M.; Nijland, Marcel

    2017-01-01

    AimsLow-grade follicular lymphoma (FL) (grade 1/2, FL1/2) has an annual risk of transformation of approximate to 3%, which is associated with aberrations in CDKN2A/B, TP53, and MYC. As in diffuse large B-cell lymphoma, high MYC expression in transformed FL (tFL) might predict a MYC breakpoint.

  17. Cancer Stem-Like Cells Accumulated in Nickel-Induced Malignant Transformation

    Science.gov (United States)

    Wang, Lei; Fan, Jia; Hitron, John Andrew; Son, Young-Ok; Wise, James T.F.; Roy, Ram Vinod; Kim, Donghern; Dai, Jin; Pratheeshkumar, Poyil; Zhang, Zhuo; Shi, Xianglin

    2016-01-01

    Nickel compounds are known as human carcinogens. Chronic environmental exposure to nickel is a worldwide health concern. Although the mechanisms of nickel-induced carcinogenesis are not well understood, recent studies suggest that stem cells/cancer stem cells are likely important targets. This study examines the role of cancer stem cells in nickel-induced cell transformation. The nontransformed human bronchial epithelial cell line (Beas-2B) was chronically exposed to nickel chloride for 12 months to induce cell transformation. Nickel induced Beas-2B cell transformation, and cancer stem-like cells were enriched in nickel-transformed cell (BNiT) population. The BNiT cancer stem-like cells demonstrated enhanced self-renewal and distinctive differentiation properties. In vivo tumorigenesis studies show that BNiT cancer stem-like cells possess a high tumor-initiating capability. It was also demonstrated that superoxide dismutase 1 was involved in the accumulation of cancer stem-like cells; the regulation of superoxide dismutase 1 expression was different in transformed stem-like cells and nontransformed. Overall, the accumulation of stem-like cells and their enhanced stemness functions contribute to nickel-induced tumorigenesis. Our study provides additional insight into the mechanisms by which metals or other chemicals can induce carcinogenesis. PMID:26962057

  18. Effects of transforming growth factor-beta1 on cell motility, collagen gel contraction, myofibroblastic differentiation, and extracellular matrix expression of human adipose-derived stem cell.

    Science.gov (United States)

    Kakudo, Natsuko; Kushida, Satoshi; Suzuki, Kenji; Ogura, Tsunetaka; Notodihardjo, Priscilla Valentin; Hara, Tomoya; Kusumoto, Kenji

    2012-12-01

    Human adipose-derived stem cells (ASCs) are adult pluripotent stem cells, and their usefulness in plastic surgery has garnered attention in recent years. Although, there have been expectations that ASCs might function in wound repair and regeneration, no studies to date have examined the role of ASCs in the mechanism that promotes wound-healing. Transforming growth factor-beta1 (TGF-β1) is a strong candidate cytokine for the triggering of mesenchymal stem cell migration, construction of extracellular matrices, and differentiation of ASCs into myofibroblasts. Cell proliferation, motility, and differentiation, as well as extracellular matrix production, play an important role in wound-healing. We have evaluated the capacity of ASCs to proliferate and their potential to differentiate into phenotypic myofibroblasts, as well as their cell motility and collagen gel contraction ability, when cultured with TGF-β1. Cell motility was analyzed using a wound-healing assay. ASCs that differentiated into myofibroblasts expressed the gene for alpha-smooth muscle actin, and its protein expression was detected immunohistochemically. The extracellular matrix expression in ASCs was evaluated using real-time RT-PCR. Based on the results, we conclude that human ASCs have the potential for cell motility, extracellular matrix gene expression, gel contraction, and differentiation into myofibroblasts and, therefore, may play an important role in the wound-healing process.

  19. Mos1 transposon-based transformation of fish cell lines using baculoviral vectors

    Energy Technology Data Exchange (ETDEWEB)

    Yokoo, Masako [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan); Fujita, Ryosuke [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan); Innate Immunity Laboratory, Graduate School of Life Science and Creative Research Institution, Hokkaido University, Sapporo 001-0021 (Japan); Nakajima, Yumiko [Functional Genomics Group, COMB, Tropical Biosphere Research Center, University of the Ryukyus, Okinawa 903-0213 (Japan); Yoshimizu, Mamoru; Kasai, Hisae [Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611 (Japan); Asano, Shin-ichiro [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan); Bando, Hisanori, E-mail: hban@abs.agr.hokudai.ac.jp [Laboratory of Applied Molecular Entomology, Division of Applied Bioscience, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589 (Japan)

    2013-09-13

    Highlights: •The baculovirus vector infiltrates the cells of economic important fishes. •Drosophila Mos1 transposase expressed in fish cells maintains its ability to localize to the nucleus. •The baculoviral vector carrying Mos1 is a useful tool to stably transform fish cells. -- Abstract: Drosophila Mos1 belongs to the mariner family of transposons, which are one of the most ubiquitous transposons among eukaryotes. We first determined nuclear transportation of the Drosophila Mos1-EGFP fusion protein in fish cell lines because it is required for a function of transposons. We next constructed recombinant baculoviral vectors harboring the Drosophila Mos1 transposon or marker genes located between Mos1 inverted repeats. The infectivity of the recombinant virus to fish cells was assessed by monitoring the expression of a fluorescent protein encoded in the viral genome. We detected transgene expression in CHSE-214, HINAE, and EPC cells, but not in GF or RTG-2 cells. In the co-infection assay of the Mos1-expressing virus and reporter gene-expressing virus, we successfully transformed CHSE-214 and HINAE cells. These results suggest that the combination of a baculovirus and Mos1 transposable element may be a tool for transgenesis in fish cells.

  20. Mos1 transposon-based transformation of fish cell lines using baculoviral vectors

    International Nuclear Information System (INIS)

    Yokoo, Masako; Fujita, Ryosuke; Nakajima, Yumiko; Yoshimizu, Mamoru; Kasai, Hisae; Asano, Shin-ichiro; Bando, Hisanori

    2013-01-01

    Highlights: •The baculovirus vector infiltrates the cells of economic important fishes. •Drosophila Mos1 transposase expressed in fish cells maintains its ability to localize to the nucleus. •The baculoviral vector carrying Mos1 is a useful tool to stably transform fish cells. -- Abstract: Drosophila Mos1 belongs to the mariner family of transposons, which are one of the most ubiquitous transposons among eukaryotes. We first determined nuclear transportation of the Drosophila Mos1-EGFP fusion protein in fish cell lines because it is required for a function of transposons. We next constructed recombinant baculoviral vectors harboring the Drosophila Mos1 transposon or marker genes located between Mos1 inverted repeats. The infectivity of the recombinant virus to fish cells was assessed by monitoring the expression of a fluorescent protein encoded in the viral genome. We detected transgene expression in CHSE-214, HINAE, and EPC cells, but not in GF or RTG-2 cells. In the co-infection assay of the Mos1-expressing virus and reporter gene-expressing virus, we successfully transformed CHSE-214 and HINAE cells. These results suggest that the combination of a baculovirus and Mos1 transposable element may be a tool for transgenesis in fish cells

  1. Cytological and oncogene alterations in radiation-transformed Syrian hamster embryo cells

    International Nuclear Information System (INIS)

    Trutschler, K.; Hieber, L.; Kellerer, A.M.

    1991-01-01

    Syrian hamster embryo (SHE) cells were neoplastically transformed by different types of ionizing radiation (γ-rays, α-particles or carbon ions). Transformed and tumor cell lines (derived from nude mice tumors) were analysed for alterations of the oncogenes c-Ha-ras and c-myc, i.e. RFLPs, gene amplifications, activation by point mutation, gene expression, and for cytological changes. In addition, the chromosome number and the numbers of micronuclei per cell have been determined in a series of cell lines. (author)

  2. Microarray analysis of altered gene expression in murine fibroblasts transformed by nickel(II) to nickel(II)-resistant malignant phenotype

    International Nuclear Information System (INIS)

    Kowara, Renata; Karaczyn, Aldona; Cheng, Robert Y.S.; Salnikow, Konstantin; Kasprzak, Kazimierz S.

    2005-01-01

    B200 cells are Ni(II)-transformed mouse BALB/c-3T3 fibroblasts displaying a malignant phenotype and increased resistance to Ni(II) toxicity. In an attempt to find genes whose expression has been altered by the transformation, the Atlas Mouse Stress/Toxicology cDNA Expression Array (Clontech Laboratories, Inc., Palo Alto, CA) was used to analyze the levels of gene expression in both parental and Ni(II)-transformed cells. Comparison of the results revealed a significant up- or downregulation of the expression of 62 of the 588 genes present in the array (approximately 10.5%) in B200 cells. These genes were assigned to different functional groups, including transcription factors and oncogenes (9/14; fractions in parentheses denote the number of up-regulated versus the total number of genes assigned to this group), stress and DNA damage response genes (11/12), growth factors and hormone receptors (6/9), metabolism (7/7), cell adhesion (2/7), cell cycle (3/6), apoptosis (3/4), and cell proliferation (2/3). Among those genes, overexpression of beta-catenin and its downstream targets c-myc and cyclin D1, together with upregulated cyclin G, points at the malignant character of B200 cells. While the increased expression of glutathione (GSH) synthetase, glutathione-S-transferase A4 (GSTA4), and glutathione-S-transferase theta (GSTT), together with high level of several genes responding to oxidative stress, suggests the enforcement of antioxidant defenses in Ni-transformed cells

  3. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium.

    Science.gov (United States)

    Pelch, Katherine E; Tokar, Erik J; Merrick, B Alex; Waalkes, Michael P

    2015-08-01

    Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10μM Cd for 11weeks (CTPE) or 5μM iAs for 29weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (>25-fold) and S100P (>40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (>15-fold) and NTM (>1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. Published by Elsevier Inc.

  4. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium

    International Nuclear Information System (INIS)

    Pelch, Katherine E.; Tokar, Erik J.; Merrick, B. Alex; Waalkes, Michael P.

    2015-01-01

    Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10 μM Cd for 11 weeks (CTPE) or 5 μM iAs for 29 weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (> 25-fold) and S100P (> 40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (> 15-fold) and NTM (> 1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. - Highlights: • Cd and iAs are known human carcinogens, yet neither appears directly mutagenic. • Prior data suggest epigenetic modification plays a role in Cd or iAs induced cancer. • Altered methylation of four misregulated genes was found in Cd or iAs transformants. • The resulting altered gene expression may be relevant to cellular

  5. Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Pelch, Katherine E.; Tokar, Erik J. [National Toxicology Program Laboratory, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States); Merrick, B. Alex [Molecular Toxicology and Informatics Group, Biomolecular Screening Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Morrisville, NC 27560 (United States); Waalkes, Michael P., E-mail: waalkes@niehs.nih.gov [National Toxicology Program Laboratory, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709 (United States)

    2015-08-01

    Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10 μM Cd for 11 weeks (CTPE) or 5 μM iAs for 29 weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (> 25-fold) and S100P (> 40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (> 15-fold) and NTM (> 1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. - Highlights: • Cd and iAs are known human carcinogens, yet neither appears directly mutagenic. • Prior data suggest epigenetic modification plays a role in Cd or iAs induced cancer. • Altered methylation of four misregulated genes was found in Cd or iAs transformants. • The resulting altered gene expression may be relevant to cellular

  6. Transforming growth factor beta 1 expression and inflammatory cells in tooth extraction socket after X-ray irradiation

    Directory of Open Access Journals (Sweden)

    Ramadhan Hardani Putra

    2016-06-01

    Full Text Available Background: Radiographic examination is often used in dentistry to evaluate tooth extraction complications. X-ray used in radiographic examination, however, has negative effects, including damage to DNA and inflammatory response during wound healing process. Purpose: This study aimed to analyze the effects of X-ray irradiation on transforming growth factor beta 1 (TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets. Method: Thirty rats were divided into three groups, which consist of control group (with a radiation of 0 mSv, treatment group 1 (with a radiation of 0.08 mSv, and treatment group 2 (with a radiation of 0.16 mSv. These rats in each group were sacrificed on days 3 and 5 after treatment. Inflammatory cells which were observed in this research were PMN, macrophages, and lymphocytes. Histopathological and immunohistochemical examinations were used to calculate the number of inflammatory cells and TGF-ß1 expression. Obtained data were analyzed using SPSS 16.0 software with one way ANOVA and Tukey’s HSD tests. Result: There was no significant decrease in the number of PMN. On the other hand, there were significant decreases in the number of macrophages and lymphocytes in the sacrificed group on day-5 with the radiation of 0.16 mSv. Similarly, the most significant decreased expression of TGF-ß1 was found in the group sacrificed on day 5 with the radiation of 0.16 mSv. Conclusion: X-ray irradiation with 0.08 mSv and 0.16 mSv doses can decrease TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets on day 3 and 5 post extraction.

  7. Transformations of C3H 10T1/2 cells by Benzo(a)pyrene and subsequent attempts at suppression of transformed foci by untransformed cells and Vitamin A

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.

    1978-01-01

    The mouse embryo cell line (C3H 10T1/2 CL8) has been shown here, in agreement with findings by others, to be transformed by benzo(a)pyrene (BP). Transformation studies were carried out at two different concentrations (0.25 μg BP/ml and 2.5 μg BP/ml) and two different cell densities (200 and 1000 cells/60 mm dish). Transformation frequencies per surviving cell were found to be greatest when the higher concentration of BP was used with the lower cell density. A comparison of these results with earlier alpha-irradiation experiments demonstrated the greater effectiveness of BP as a transforming agent in this cell system, although the foci produced by the two agents were morphologically similar. Attempts made to eliminate the expression of BP transformed foci by two different techniques were unsuccessful, although one of these had previously been shown to be effective with cells transformed by alpha particle irradiation. The two systems tested were treatment with retinyl acetate, a common nutritional form of Vitamin A and the previously successful technique - growth of transformed cells with large numbers of untransformed cells. The differences between the BP-induced transformations and those induced by alpha particle irradiation may result from intrinsic differences in the mechanism of action of the two carcinogenic agents, differences in the number of cell generations between the induction of the transformed foci and the subsequent treatment of the cells, or genetic differences between different foci

  8. Interleukin-8 (IL-8) over-production and autocrine cell activation are key factors in monomethylarsonous acid [MMA(III)]-induced malignant transformation of urothelial cells

    International Nuclear Information System (INIS)

    Escudero-Lourdes, C.; Wu, T.; Camarillo, J.M.; Gandolfi, A.J.

    2012-01-01

    The association between chronic human exposure to arsenicals and bladder cancer development is well recognized; however, the underlying molecular mechanisms have not been fully determined. We propose that inflammatory responses can play a pathogenic role in arsenic-related bladder carcinogenesis. In previous studies, it was demonstrated that chronic exposure to 50 nM monomethylarsenous acid [MMA(III)] leads to malignant transformation of an immortalized model of urothelial cells (UROtsa), with only 3 mo of exposure necessary to trigger the transformation-related changes. In the three-month window of exposure, the cells over-expressed pro-inflammatory cytokines (IL-1β, IL-6 and IL-8), consistent with the sustained activation of NFKβ and AP1/c-jun, ERK2, and STAT3. IL-8 was over-expressed within hours after exposure to MMA(III), and sustained over-expression was observed during chronic exposure. In this study, we profiled IL-8 expression in UROtsa cells exposed to 50 nM MMA(III) for 1 to 5 mo. IL-8 expression was increased mainly in cells after 3 mo MMA(III) exposure, and its production was also found increased in tumors derived from these cells after heterotransplantation in SCID mice. UROtsa cells do express both receptors, CXCR1 and CXCR2, suggesting that autocrine cell activation could be important in cell transformation. Supporting this observation and consistent with IL-8 over-expression, CXCR1 internalization was significantly increased after three months of exposure to MMA(III). The expression of MMP-9, cyclin D1, bcl-2, and VGEF was significantly increased in cells exposed to MMA(III) for 3 mo, but these mitogen-activated kinases were significantly decreased after IL-8 gene silencing, together with a decrease in cell proliferation rate and in anchorage-independent colony formation. These results suggest a relevant role of IL-8 in MMA(III)-induced UROtsa cell transformation. -- Highlights: ► IL-8 is over-expressed in human MMA(III)-exposed urothelial

  9. Population heterogeneity in the surface expression of Ulex europaeus I-lectin (UEA I)-binding sites in cultured malignant and transformed cells

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, I.; Lehtonen, E.; Naervaenen, O.; Leivo, I.; Lehto, V.P.

    1985-11-01

    We studied the binding of fluorochrome-coupled Ulex europaeus I-lectin (UEA-I) to cultured malignant cells: all human malignant and transformed cells and also mouse teratocarcinoma cells examined gave a homogeneous cell membrane-type of surface staining only in some of the cells. Such a population heterogeneity appeared to be independent of the cell cycle. Instead, other lectin conjugates used bound homogeneously to all cell. In permeabilized cells, a juxtanuclear reticular staining of the Golgi apparatus was seen in the UEA-I-positive cells. No staining of the pericellular matrix components, produced by malignant cells grown in serum-free culture medium, could be obtained with TRITC-UEA-I. UEA-I-lectin recognized most polypeptides from A8387 fibrosarcoma cells and HeLa cells, metabolically labelled with (/sup 3/H)fucose. Furthermore, surface labelling of these cells with the neuraminidase-galactose oxidase/sodium borohydride method disclosed that both UEA-I and Ricinus communis agglutinin I revealed the same major surface glycoproteins. Results with metabolically labelled cells showed, in addition, that UEA-I-lectin did not bind to secreted glycoproteins produced by A8387 cells and recognized by other lectins. The results indicate that transformed and malignant cells show a distinct population heterogeneity in their expression of some cell surface-associated fucosyl glycoconjugates. The results also suggest that malignant cells can glycosylate their membrane and secreted glycoproteins in a different manner.

  10. Genome-wide DNA methylation reprogramming in response to inorganic arsenic links inhibition of CTCF binding, DNMT expression and cellular transformation

    Science.gov (United States)

    Rea, Matthew; Eckstein, Meredith; Eleazer, Rebekah; Smith, Caroline; Fondufe-Mittendorf, Yvonne N.

    2017-02-01

    Chronic low dose inorganic arsenic (iAs) exposure leads to changes in gene expression and epithelial-to-mesenchymal transformation. During this transformation, cells adopt a fibroblast-like phenotype accompanied by profound gene expression changes. While many mechanisms have been implicated in this transformation, studies that focus on the role of epigenetic alterations in this process are just emerging. DNA methylation controls gene expression in physiologic and pathologic states. Several studies show alterations in DNA methylation patterns in iAs-mediated pathogenesis, but these studies focused on single genes. We present a comprehensive genome-wide DNA methylation analysis using methyl-sequencing to measure changes between normal and iAs-transformed cells. Additionally, these differential methylation changes correlated positively with changes in gene expression and alternative splicing. Interestingly, most of these differentially methylated genes function in cell adhesion and communication pathways. To gain insight into how genomic DNA methylation patterns are regulated during iAs-mediated carcinogenesis, we show that iAs probably targets CTCF binding at the promoter of DNA methyltransferases, regulating their expression. These findings reveal how CTCF binding regulates DNA methyltransferase to reprogram the methylome in response to an environmental toxin.

  11. Biochemical transformation of deoxythymidine kinase-deficient mouse cells with uv-irradiated equine herpesvirus type 1

    International Nuclear Information System (INIS)

    Allen, G.P.; McGowan, J.J.; Gentry, G.A.; Randall, C.C.

    1978-01-01

    A line of 3T3 mouse cells lacking deoxythymidine kinase (dTK - ) was stably transformed to the dTK + phenotype after exposure to uv-irradiated equine herpesvirus type 1 (EHV-1). Biochemical transformants were isolated in a system selective for the dTK + phenotype (Eagle minimal essential medium containing 10 -4 M hypoxanthine, 6 x 10 -7 M aminopterin, and 2 x 10 -5 M deoxythymidine). Transformation was accompanied by the acquisition of a dTK activity with immunological, electrophoretic, and biochemical characteristics identical to those of the dTK induced by EHV-1 during productive infection. The transformed cells have been maintained in selective culture medium for more than 50 passages and have retained the capacity to express EHV-1-specific antigens. Spontaneous release of infectious virus has not been detected in the transformed lines, and the cells were not oncogenic for athymic nude mice. In contrast to normal dTK + 3T3 cells, EHV-1 transformants were unable to grow in the presence of arabinosylthymine, a drug selectively phosphorylated by herpesvirus-coded dTK's. These results indicate that a portion of the EHV-1 genome is able to persist in the transformed cells for many generations and be expressed as an enzymatically active viral gene product

  12. Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanism in lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Song-Ze, E-mail: dingsongze@hotmail.com [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Yang, Yu-Xiu; Li, Xiu-Ling [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Michelli-Rivera, Audrey [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Han, Shuang-Yin [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Wang, Lei; Pratheeshkumar, Poyil; Wang, Xin; Lu, Jian; Yin, Yuan-Qin; Budhraja, Amit; Hitron, Andrew J. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

    2013-05-15

    Hexavalent chromium [Cr(VI)] is an important human carcinogen associated with pulmonary diseases and lung cancer. Exposure to Cr(VI) induces DNA damage, cell morphological change and malignant transformation in human lung epithelial cells. Despite extensive studies, the molecular mechanisms remain elusive, it is also not known if Cr(VI)-induced transformation might accompany with invasive properties to facilitate metastasis. We aimed to study Cr(VI)-induced epithelial–mesenchymal transition (EMT) and invasion during oncogenic transformation in lung epithelial cells. The results showed that Cr(VI) at low doses represses E-cadherin mRNA and protein expression, enhances mesenchymal marker vimentin expression and transforms the epithelial cell into fibroblastoid morphology. Cr(VI) also increases cell invasion and promotes colony formation. Further studies indicated that Cr(VI) uses multiple mechanisms to repress E-cadherin expression, including activation of E-cadherin repressors such as Slug, ZEB1, KLF8 and enhancement the binding of HDAC1 in E-cadherin gene promoter, but DNA methylation is not responsible for the loss of E-cadherin. Catalase reduces Cr(VI)-induced E-cadherin and vimentin protein expression, attenuates cell invasion in matrigel and colony formation on soft agar. These results demonstrate that exposure to a common human carcinogen, Cr(VI), induces EMT and invasion during oncogenic transformation in lung epithelial cells and implicate in cancer metastasis and prevention. - Graphical abstract: Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanisms in lung epithelial cells. - Highlights: • We study if Cr(VI) might induce EMT and invasion in epithelial cells. • Cr(VI) induces EMT by altering E-cadherin and vimentin expression. • It also increases cell invasion and promotes oncogenic transformation. • Catalase reduces Cr(VI)-induced EMT, invasion and

  13. Distinct regulation of c-myb gene expression by HoxA9, Meis1 and Pbx proteins in normal hematopoietic progenitors and transformed myeloid cells

    International Nuclear Information System (INIS)

    Dassé, E; Volpe, G; Walton, D S; Wilson, N; Del Pozzo, W; O'Neill, L P; Slany, R K; Frampton, J; Dumon, S

    2012-01-01

    The proto-oncogenic protein c-Myb is an essential regulator of hematopoiesis and is frequently deregulated in hematological diseases such as lymphoma and leukemia. To gain insight into the mechanisms underlying the aberrant expression of c-Myb in myeloid leukemia, we analyzed and compared c-myb gene transcriptional regulation using two cell lines modeling normal hematopoietic progenitor cells (HPCs) and transformed myelomonocytic blasts. We report that the transcription factors HoxA9, Meis1, Pbx1 and Pbx2 bind in vivo to the c-myb locus and maintain its expression through different mechanisms in HPCs and leukemic cells. Our analysis also points to a critical role for Pbx2 in deregulating c-myb expression in murine myeloid cells cotransformed by the cooperative activity of HoxA9 and Meis1. This effect is associated with an intronic positioning of epigenetic marks and RNA polymerase II binding in the orthologous region of a previously described alternative promoter for c-myb. Taken together, our results could provide a first hint to explain the abnormal expression of c-myb in leukemic cells

  14. Stable Plastid Transformation for High-Level Recombinant Protein Expression: Promises and Challenges

    Directory of Open Access Journals (Sweden)

    Meili Gao

    2012-01-01

    Full Text Available Plants are a promising expression system for the production of recombinant proteins. However, low protein productivity remains a major obstacle that limits extensive commercialization of whole plant and plant cell bioproduction platform. Plastid genetic engineering offers several advantages, including high levels of transgenic expression, transgenic containment via maternal inheritance, and multigene expression in a single transformation event. In recent years, the development of optimized expression strategies has given a huge boost to the exploitation of plastids in molecular farming. The driving forces behind the high expression level of plastid bioreactors include codon optimization, promoters and UTRs, genotypic modifications, endogenous enhancer and regulatory elements, posttranslational modification, and proteolysis. Exciting progress of the high expression level has been made with the plastid-based production of two particularly important classes of pharmaceuticals: vaccine antigens, therapeutic proteins, and antibiotics and enzymes. Approaches to overcome and solve the associated challenges of this culture system that include low transformation frequencies, the formation of inclusion bodies, and purification of recombinant proteins will also be discussed.

  15. Podoplanin expression in oral potentially malignant disorders and oral squamous cell carcinoma.

    Science.gov (United States)

    A G, Deepa; Janardanan-Nair, Bindu; B R, Varun

    2017-12-01

    Podoplanin is a type I transmembrane sialomucin-like glycoprotein that is specifically expressed in lymphatic endothelial cells. Studies have shown that assessment of podoplanin expression in the epithelial cells can be used to predict the malignant transformation of potentially malignant disorders and the metastatic tendency of primary head and neck squamous cell carcinoma. The aim of our study was to compare the expression of podoplanin in oral leukoplakia, oral submucous fibrosis and oral squamous cell carcinoma with that in normal buccal mucosa by immunohistochemical methods. Immunohistochemical expression of podoplanin was analyzed in 20 cases each of oral leukoplakia, oral submucous fibrosis, oral squamous cell carcinoma and normal buccal mucosa, with monoclonal antibody D2-40. The expression of podoplanin was graded from grade 0-4. There was a statistically significant upregulation of the grades of podoplanin expression in oral squamous cell carcinoma(100%), oral submucous fibrosis (90%) and oral leukoplakia (65%) when compared to that in normal mucosa(35%). Podoplanin expression increased with decrease in grades of differentiation in oral squamous cell carcinoma . Podoplanin expression in the samples of oral submucous fibrosis was higher than that in oral leukoplakia. Evaluation of podoplanin expression in the epithelial cells of oral dysplastic lesions may provide valuable information to predict their risk of malignant transformation. Key words: Immunohistochemistry, Oral leukoplakia, Oral submucous fibrosis, Podoplanin, Squamous cell carcinoma.

  16. Behavioral analysis of Drosophila transformants expressing human taste receptor genes in the gustatory receptor neurons.

    Science.gov (United States)

    Adachi, Ryota; Sasaki, Yuko; Morita, Hiromi; Komai, Michio; Shirakawa, Hitoshi; Goto, Tomoko; Furuyama, Akira; Isono, Kunio

    2012-06-01

    Transgenic Drosophila expressing human T2R4 and T2R38 bitter-taste receptors or PKD2L1 sour-taste receptor in the fly gustatory receptor neurons and other tissues were prepared using conventional Gal4/UAS binary system. Molecular analysis showed that the transgene mRNAs are expressed according to the tissue specificity of the Gal4 drivers. Transformants expressing the transgene taste receptors in the fly taste neurons were then studied by a behavioral assay to analyze whether transgene chemoreceptors are functional and coupled to the cell response. Since wild-type flies show strong aversion against the T2R ligands as in mammals, the authors analyzed the transformants where the transgenes are expressed in the fly sugar receptor neurons so that they promote feeding ligand-dependently if they are functional and activate the neurons. Although the feeding preference varied considerably among different strains and individuals, statistical analysis using large numbers of transformants indicated that transformants expressing T2R4 showed a small but significant increase in the preference for denatonium and quinine, the T2R4 ligands, as compared to the control flies, whereas transformants expressing T2R38 did not. Similarly, transformants expressing T2R38 and PKD2L1 also showed a similar preference increase for T2R38-specific ligand phenylthiocarbamide (PTC) and a sour-taste ligand, citric acid, respectively. Taken together, the transformants expressing mammalian taste receptors showed a small but significant increase in the feeding preference that is taste receptor and also ligand dependent. Although future improvements are required to attain performance comparable to the endogenous robust response, Drosophila taste neurons may serve as a potential in vivo heterologous expression system for analyzing chemoreceptor function.

  17. Transformation by Oncogenic Ras Expands the Early Genomic Response to Transforming Growth Factor β in Intestinal Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Carl E. Allen

    2008-10-01

    Full Text Available A substantial body of evidence implicates TGFβ as a tumor promoter in epithelial cells that have become resistant to its tumor suppressor activity. To better understand early, genome-wide TGFβ responses in cells resistant to growth inhibition by TGFβ, we used microarray analysis in a well-defined cell culture system of sensitive and resistant intestinal epithelial cells. TGFβ-regulated gene expression in TGFβ-growth-sensitive, nontransformed rat intestinal epithelial cells (RIE-1 was compared to expression in TGFβ-growth-resistant RIE cells stably transformed by oncogenic Ras(12V. Treatment of RIE-1 cells with 2 ng/ml TGFβ1 for 1 hour increased the expression of eight gene sequences by 2.6-fold or more, whereas eight were down regulated 2.6-fold. In RIE-Ras(12V cells, 42 gene sequences were upregulated and only 3 were down-regulated. Comparison of RIE and RIE-Ras(12V identified 37 gene sequences as unique, Ras-dependent genomic targets of TGFβ1. TGFβ-regulation of connective tissue growth factor and vascular endothelial growth factor, two genes up-regulated in RIE-Ras cells and previously implicated in tumor promotion, was independently confirmed and further characterized by Northern analysis. Our data indicate that overexpression of oncogenic Ras in intestinal epithelial cells confers a significantly expanded repertoire of robust, early transcriptional responses to TGFβ via signaling pathways yet to be fully elucidated but including the canonical Raf-1/MAPK/Erk pathway. Loss of sensitivity to growth inhibition by TGFβ does not abrogate TGFβ signaling and actually expands the early transcriptional response to TGFβ1. Expression of some of these genes may confer to Ras-transformed cells characteristics favorable for tumor promotion.

  18. Evaluation of transforming growth factor-β1 suppress Pokemon/epithelial-mesenchymal transition expression in human bladder cancer cells.

    Science.gov (United States)

    Li, Wei; Kidiyoor, Amritha; Hu, Yangyang; Guo, Changcheng; Liu, Min; Yao, Xudong; Zhang, Yuanyuan; Peng, Bo; Zheng, Junhua

    2015-02-01

    Transforming growth factor-β1 (TGF-β1) plays a dual role in apoptosis and in proapoptotic responses in the support of survival in a variety of cells. The aim of this study was to determine the function of TGF-β1 in bladder cancer cells and the relationship with POK erythroid myeloid ontogenic factor (Pokemon). TGF-β1 and its receptors mediate several tumorigenic cascades that regulate cell proliferation, migration, and survival of bladder cancer cells. Bladder cancer cells T24 were treated with different levels of TGF-β1. Levels of Pokemon, E-cadherin, Snail, MMP2, MMP9, Twist, VEGF, and β-catenin messenger RNA (mRNA) and protein were examined by real-time quantitative fluorescent PCR and Western blot analysis, respectively. The effects of TGF-β1 on epithelial-mesenchymal transition of T24 cells were evaluated with wound-healing assay, proliferation of T24 was evaluated with reference to growth curves with MTT assay, and cell invasive ability was investigated by Transwell assay. Data show that Pokemon was inhibited by TGF-β1 treatment; the gene and protein of E-cadherin and β-catenin expression level showed decreased markedly after TGF-β1 treatment (P Pokemon, β-catenin, and E-cadherin. The high expression of TGF-β1 leads to an increase in the phenotype and apical-base polarity of epithelial cells. These changes of cells may result in the recurrence and progression of bladder cancer at last. Related mechanism is worthy of further investigation.

  19. Rat primary embryo fibroblast cells suppress transformation by the E6 and E7 genes of human papillomavirus type 16 in somatic hybrid cells.

    OpenAIRE

    Miyasaka, M; Takami, Y; Inoue, H; Hakura, A

    1991-01-01

    The E6 and E7 genes of human papillomavirus type 16 (HPV-16) transform established lines of rat cells but not rat cells in primary culture irrespective of the expression of the two genes. The reason for this difference between the susceptibilities of cell lines and primary cells was examined by using hybrid cells obtained by somatic cell fusion of rat cell lines transformed by the E6 and E7 genes of HPV-16 and freshly isolated rat embryo fibroblast cells. In these hybrid cells, transformed ph...

  20. Repair-dependent cell radiation survival and transformation: an integrated theory

    International Nuclear Information System (INIS)

    Sutherland, John C

    2014-01-01

    The repair-dependent model of cell radiation survival is extended to include radiation-induced transformations. The probability of transformation is presumed to scale with the number of potentially lethal damages that are repaired in a surviving cell or the interactions of such damages. The theory predicts that at doses corresponding to high survival, the transformation frequency is the sum of simple polynomial functions of dose; linear, quadratic, etc, essentially as described in widely used linear-quadratic expressions. At high doses, corresponding to low survival, the ratio of transformed to surviving cells asymptotically approaches an upper limit. The low dose fundamental- and high dose plateau domains are separated by a downwardly concave transition region. Published transformation data for mammalian cells show the high-dose plateaus predicted by the repair-dependent model for both ultraviolet and ionizing radiation. For the neoplastic transformation experiments that were analyzed, the data can be fit with only the repair-dependent quadratic function. At low doses, the transformation frequency is strictly quadratic, but becomes sigmodial over a wider range of doses. Inclusion of data from the transition region in a traditional linear-quadratic analysis of neoplastic transformation frequency data can exaggerate the magnitude of, or create the appearance of, a linear component. Quantitative analysis of survival and transformation data shows good agreement for ultraviolet radiation; the shapes of the transformation components can be predicted from survival data. For ionizing radiations, both neutrons and x-rays, survival data overestimate the transforming ability for low to moderate doses. The presumed cause of this difference is that, unlike UV photons, a single x-ray or neutron may generate more than one lethal damage in a cell, so the distribution of such damages in the population is not accurately described by Poisson statistics. However, the complete

  1. Inhibition of the Hedgehog Signaling Pathway Depresses the Cigarette Smoke-Induced Malignant Transformation of 16HBE Cells on a Microfluidic Chip.

    Science.gov (United States)

    Qin, Yong-Xin; Yang, Zhi-Hui; Du, Xiao-Hui; Zhao, Hui; Liu, Yuan-Bin; Guo, Zhe; Wang, Qi

    2018-05-20

    The hedgehog signaling system (HHS) plays an important role in the regulation of cell proliferation and differentiation during the embryonic phases. However, little is known about the involvement of HHS in the malignant transformation of cells. This study aimed to detect the role of HHS in the malignant transformation of human bronchial epithelial (16HBE) cells. In this study, two microfluidic chips were designed to investigate cigarette smoke extract (CSE)-induced malignant transformation of cells. Chip A contained a concentration gradient generator, while chip B had four cell chambers with a central channel. The 16HBE cells cultured in chip A were used to determine the optimal concentration of CSE for inducing malignant transformation. The 16HBE cells in chip B were cultured with 12.25% CSE (Group A), 12.25% CSE + 5 μmol/L cyclopamine (Group B), or normal complete medium as control for 8 months (Group C), to establish the in vitro lung inflammatory-cancer transformation model. The transformed cells were inoculated into 20 nude mice as cells alone (Group 1) or cells with cyclopamine (Group 2) for tumorigenesis testing. Expression of HHS proteins was detected by Western blot. Data were expressed as mean ± standard deviation. The t-test was used for paired samples, and the difference among groups was analyzed using a one-way analysis of variance. The optimal concentration of CSE was 12.25%. Expression of HHS proteins increased during the process of malignant transformation (Group B vs. Group A, F = 7.65, P < 0.05). After CSE exposure for 8 months, there were significant changes in cellular morphology, which allowed the transformed cells to grow into tumors in 40 days after being inoculated into nude mice. Cyclopamine could effectively depress the expression of HHS proteins (Group C vs. Group B, F = 6.47, P < 0.05) and prevent tumor growth in nude mice (Group 2 vs. Group 1, t = 31.59, P < 0.01). The activity of HHS is upregulated during the CSE-induced malignant

  2. Neoplastic transformation of hamster embryo cells irradiated in utero and assayed in vitro

    International Nuclear Information System (INIS)

    Borek, C.; Pain, C.; Mason, H.

    1977-01-01

    It is stated that induction of neoplastic transformation in vitro by x-rays and neutrons has been reported, and the authors had previously found that transformation by x-rays could be detected at doses as low as 1 R and the rate of transformation increased with dose, reaching a peak of 1% between 150 and 300 R. This frequency of neoplastic transformation in vitro is much higher than the frequency of radiation induced tumors observed after exposing animals to similar doses of radiation. Studies are here reported showing that malignant transformed cells can be obtained from embryos irradiated in utero and assayed in vitro, and that the frequency of transformation is at least tenfold lower than when the irradiations are performed in vitro, and thus closer to the incidence in animals. Hamster embryo cells were used for the studies. Questions that arise are as follows: does the host mediate in modulating transformation by radiation; is there a repair of transforming events before they can be expressed; and how significant is the state of cells during irradiation in determining the rate of transformation. It is known from in vitro studies that cell replication is required for fixation of the transformation. With the in vitro technique cells are seeded as single cells with ample opportunity to divide. In addition they are not in contact with one another, and constitute a mixture of cell types from many tissues. In utero the situation is quite different; the embryonic cells are irradiated as tissues where there is cell to cell contact in tissue-specific arrangements, and where the rate of cell replication varies with the tissue. It remains to be seen which of these factors, if any, is responsible for the lowered yield of transformed cells characteristic of in utero as opposed to in vitro irradiation. (U.K.)

  3. Radiation-induced transformation in oncogene primed C3H/10T1/2 cells; a new system for analysis of multi-step transformation in vitro

    International Nuclear Information System (INIS)

    Drozdoff, V.V.

    1988-01-01

    Several established rodent cell lines, such as C3H/10T1/2 fibroblasts, have been developed to study radiation and chemically-induced malignant transformation. Most experimental evidence has supported the idea that transformation in 10T1/2 cells involved at least two steps but that the apparent frequency of transformation depends on the density of plated cells. A new approach is presented here for studying radiation-induced transformation. An oncogene primed cell system (C3H-myc) was developed by introducing a constitutively active mouse c-myc gene into 10T1/2 cells. A primary goal was to determine if the introduction of an activated oncogene could substitute for one of the required steps in radiation-induced transformation. Results are presented that show that the expression of the exogenous myc gene significantly increased the frequency of radiation-induced transformation in these cells. Subculture experiments performed to analyze the kinetics of transformation in C3H-myc cells and reconstruction experiments allowing the effects of normal cells on radiation-induced transformants to be determined indicated that transformed cells arose very shortly after irradiation. These results support the conclusion that a radiation-induced event can complement the effect of myc in C3H-myc cells and directly result in transformation. This system thus provides an opportunity to isolate early steps in radiation-induced transformation and should facilitate the identification and analysis of these events

  4. Retroviral expression screening of oncogenes in natural killer cell leukemia.

    Science.gov (United States)

    Choi, Young Lim; Moriuchi, Ryozo; Osawa, Mitsujiro; Iwama, Atsushi; Makishima, Hideki; Wada, Tomoaki; Kisanuki, Hiroyuki; Kaneda, Ruri; Ota, Jun; Koinuma, Koji; Ishikawa, Madoka; Takada, Shuji; Yamashita, Yoshihiro; Oshimi, Kazuo; Mano, Hiroyuki

    2005-08-01

    Aggressive natural killer cell leukemia (ANKL) is an intractable malignancy that is characterized by the outgrowth of NK cells. To identify transforming genes in ANKL, we constructed a retroviral cDNA expression library from an ANKL cell line KHYG-1. Infection of 3T3 cells with recombinant retroviruses yielded 33 transformed foci. Nucleotide sequencing of the DNA inserts recovered from these foci revealed that 31 of them encoded KRAS2 with a glycine-to-alanine mutation at codon 12. Mutation-specific PCR analysis indicated that the KRAS mutation was present only in KHYG-1 cells, not in another ANKL cell line or in clinical specimens (n=8).

  5. Suppression of transformed foci, induced by alpha radiation of C3H 10T1/2 cells, by untransformed cells

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, M.A.; Henning, C.B.

    1978-01-01

    The C3H 10T1/2 CL8 cell line obtained from a mouse embryo has been widely used for screening chemical carcinogens. Transformed foci are easily distinguishable in this system as crisscrossed, piled-up cells which stain more deeply than the surrounding untransformed cells. When these foci are ringcloned and subcultured, they have been shown to give rise to malignant tumors in C3H immunodepressed mice. Previous work showed that such malignant transformations, which occurred with a dose dependent frequency, could be induced by alpha particle irradiation. The present study, in turn, demonstrates that the expression of these transformations can be completely suppressed by co-cultivating the transformed cells with a large number of untransformed cells. The precise ratio of the number of untransformed cells to transformed cells to give complete suppression was found to vary in different experiments. Maximum effects were seen when a small number of transformed cells in low passage were used. These experiments may provide at least a partial explanation for the greatly increased frequency of transformations per cell irradiated in vitro, compared with the number of tumors observed after irradiation of the same number of cells in vivo. In addition, if conditions could be optimized whereby transformed foci could reproducibly be eliminated by the use of a known number of untransformed cells, this might have important applications in the prevention and treatment of certain human cancers

  6. Merkel Cell Polyomavirus Small T Antigen Promotes Pro-Glycolytic Metabolic Perturbations Required for Transformation.

    Directory of Open Access Journals (Sweden)

    Christian Berrios

    2016-11-01

    Full Text Available Merkel cell polyomavirus (MCPyV is an etiological agent of Merkel cell carcinoma (MCC, a highly aggressive skin cancer. The MCPyV small tumor antigen (ST is required for maintenance of MCC and can transform normal cells. To gain insight into cellular perturbations induced by MCPyV ST, we performed transcriptome analysis of normal human fibroblasts with inducible expression of ST. MCPyV ST dynamically alters the cellular transcriptome with increased levels of glycolytic genes, including the monocarboxylate lactate transporter SLC16A1 (MCT1. Extracellular flux analysis revealed increased lactate export reflecting elevated aerobic glycolysis in ST expressing cells. Inhibition of MCT1 activity suppressed the growth of MCC cell lines and impaired MCPyV-dependent transformation of IMR90 cells. Both NF-κB and MYC have been shown to regulate MCT1 expression. While MYC was required for MCT1 induction, MCPyV-induced MCT1 levels decreased following knockdown of the NF-κB subunit RelA, supporting a synergistic activity between MCPyV and MYC in regulating MCT1 levels. Several MCC lines had high levels of MYCL and MYCN but not MYC. Increased levels of MYCL was more effective than MYC or MYCN in increasing extracellular acidification in MCC cells. Our results demonstrate the effects of MCPyV ST on the cellular transcriptome and reveal that transformation is dependent, at least in part, on elevated aerobic glycolysis.

  7. Genetic changes in Mammalian cells transformed by helium cells

    Energy Technology Data Exchange (ETDEWEB)

    Durante, M.; Grossi, G. (Naples Univ. (Italy). Dipt. di Scienze Fisiche); Yang, T.C.; Roots, R. (Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    Midterm Syrian Hamster embryo (SHE) cells were employed to study high LET-radiation induced tumorigenesis. Normal SHE cells (secondary passage) were irradiated with accelerated helium ions at an incident energy of 22 MeV/u (9--10 keV/{mu}m). Transformed clones were isolated after growth in soft agar of cells obtained from the foci of the initial monolayer plated postirradiation. To study the progression process of malignant transformation, the transformed clones were followed by monolayer subculturing for prolonged periods of time. Subsequently, neoplasia tests in nude mice were done. In this work, however, we have focused on karyotypic changes in the banding patterns of the chromosomes during the early part of the progressive process of cell transformation for helium ion-induced transformed cells. 26 refs., 5 figs., 2 tabs.

  8. Cytoskeletal dynamics in interphase, mitosis and cytokinesis analysed through Agrobacterium-mediated transient transformation of tobacco BY-2 cells.

    Science.gov (United States)

    Buschmann, H; Green, P; Sambade, A; Doonan, J H; Lloyd, C W

    2011-04-01

    Transient transformation with Agrobacterium is a widespread tool allowing rapid expression analyses in plants. However, the available methods generate expression in interphase and do not allow the routine analysis of dividing cells. Here, we present a transient transformation method (termed 'TAMBY2') to enable cell biological studies in interphase and cell division. Agrobacterium-mediated transient gene expression in tobacco BY-2 was analysed by Western blotting and quantitative fluorescence microscopy. Time-lapse microscopy of cytoskeletal markers was employed to monitor cell division. Double-labelling in interphase and mitosis enabled localization studies. We found that the transient transformation efficiency was highest when BY-2/Agrobacterium co-cultivation was performed on solid medium. Transformants produced in this way divided at high frequency. We demonstrated the utility of the method by defining the behaviour of a previously uncharacterized microtubule motor, KinG, throughout the cell cycle. Our analyses demonstrated that TAMBY2 provides a flexible tool for the transient transformation of BY-2 with Agrobacterium. Fluorescence double-labelling showed that KinG localizes to microtubules and to F-actin. In interphase, KinG accumulates on microtubule lagging ends, suggesting a minus-end-directed function in vivo. Time-lapse studies of cell division showed that GFP-KinG strongly labels preprophase band and phragmoplast, but not the metaphase spindle. © 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.

  9. Construction of a high-EGFR expression cell line and its biological ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... activator of transcription (STAT) pathways, which regulate cell transformation ... Construction of a EGFR eukaryotic expression vector. The plasmid .... was 4-5 times greater in the Aft-HEK293 cells following transfection. EGFR ...

  10. Atypical protein kinase C activity is required for extracellular matrix degradation and invasion by Src-transformed cells.

    Science.gov (United States)

    Rodriguez, Elena M; Dunham, Elizabeth E; Martin, G Steven

    2009-10-01

    Atypical protein kinase C (aPKC) isoforms have been shown to mediate Src-dependent signaling in response to growth factor stimulation. To determine if aPKC activity contributes to the transformed phenotype of cells expressing oncogenic Src, we have examined the activity and function of aPKCs in 3T3 cells expressing viral Src (v-Src). aPKC activity and tyrosine phosphorylation were found to be elevated in some but not all clones of mouse fibroblasts expressing v-Src. aPKC activity was inhibited either by addition of a membrane-permeable pseudosubstrate, by expression of a dominant-negative aPKC, or by RNAi-mediated knockdown of specific aPKC isoforms. aPKC activity contributes to morphological transformation and stress fiber disruption, and is required for migration of Src-transformed cells and for their ability to polarize at the edge of a monolayer. The lambda isoform of aPKC is specifically required for invasion through extracellular matrix in Boyden chamber assays and for degradation of the extracellular matrix in in situ zymography assays. Tyrosine phosphorylation of aPKClambda is required for its ability to promote cell invasion. The defect in invasion upon aPKC inhibition appears to result from a defect in the assembly and/or function of podosomes, invasive adhesions on the ventral surface of the cell that are sites of protease secretion. aPKC was also found to localize to podosomes of v-Src transformed cells, suggesting a direct role for aPKC in podosome assembly and/or function. We conclude that basal or elevated aPKC activity is required for the ability of Src-transformed cells to degrade and invade the extracellular matrix. Copyright 2009 Wiley-Liss, Inc.

  11. Expression of a fms-related oncogene in carcinogen-induced neoplastic epithelial cells

    International Nuclear Information System (INIS)

    Walker, C.; Nettesheim, P.; Barrett, J.C.; Gilmer, T.M.

    1987-01-01

    Following carcinogen exposure in vitro, normal rat tracheal epithelial cells are transformed in a multistage process in which the cultured cells become immortal and ultimately, neoplastic. Five cell lines derived from tumors produced by neoplastically transformed rat tracheal epithelial cells were examined for the expression of 11 cellular oncogenes previously implicated in pulmonary or epithelial carcinogenesis. RNA homologous to fms was expressed at a level 5-19 times higher than normal tracheal epithelial cells in three of five of the tumor-derived lines. All three lines expressing high levels of fms-related RNA gave rise to invasive tumors of epithelial origin when injected into nude mice. Increased expression of the fms-related mRNA was not due to gene amplification, and no gene rearrangement was detected by Southern analyses. RNA blot analysis using a 3' v-fms probe detected a 9.5-kilobase message in the three tumor-derived lines, whereas both normal rat aveolar macrophages and the human choriocarcinoma line BeWo expressed a fms transcript of ≅ 4 kilobases. The authors conclude from these data that the gene expressed as a 9.5-kilobase transcript in these neoplastic epithelial cells is a member of a fms-related gene family but may be distinct from the gene that encodes the macrophage colony-stimulating factor (CSF-1) receptor

  12. Dynamic modulation of thymidylate synthase gene expression and fluorouracil sensitivity in human colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Kentaro Wakasa

    Full Text Available Biomarkers have revolutionized cancer chemotherapy. However, many biomarker candidates are still in debate. In addition to clinical studies, a priori experimental approaches are needed. Thymidylate synthase (TS expression is a long-standing candidate as a biomarker for 5-fluorouracil (5-FU treatment of cancer patients. Using the Tet-OFF system and a human colorectal cancer cell line, DLD-1, we first constructed an in vitro system in which TS expression is dynamically controllable. Quantitative assays have elucidated that TS expression in the transformant was widely modulated, and that the dynamic range covered 15-fold of the basal level. 5-FU sensitivity of the transformant cells significantly increased in response to downregulated TS expression, although being not examined in the full dynamic range because of the doxycycline toxicity. Intriguingly, our in vitro data suggest that there is a linear relationship between TS expression and the 5-FU sensitivity in cells. Data obtained in a mouse model using transformant xenografts were highly parallel to those obtained in vitro. Thus, our in vitro and in vivo observations suggest that TS expression is a determinant of 5-FU sensitivity in cells, at least in this specific genetic background, and, therefore, support the possibility of TS expression as a biomarker for 5-FU-based cancer chemotherapy.

  13. Arsenite evokes IL-6 secretion, autocrine regulation of STAT3 signaling, and miR-21 expression, processes involved in the EMT and malignant transformation of human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Luo, Fei; Xu, Yuan; Ling, Min; Zhao, Yue; Xu, Wenchao; Liang, Xiao; Jiang, Rongrong; Wang, Bairu; Bian, Qian; Liu, Qizhan

    2013-01-01

    Arsenite is an established human carcinogen, and arsenite-induced inflammation contributes to malignant transformation of cells, but the molecular mechanisms by which cancers are produced remain to be established. The present results showed that, evoked by arsenite, secretion of interleukin-6 (IL-6), a pro-inflammatory cytokine, led to the activation of STAT3, a transcription activator, and to increased levels of a microRNA, miR-21. Blocking IL-6 with anti-IL-6 antibody and inhibiting STAT3 activation reduced miR-21 expression. For human bronchial epithelial cells, cultured in the presence of anti-IL-6 antibody for 3 days, the arsenite-induced EMT and malignant transformation were reversed. Thus, IL-6, acting on STAT3 signaling, which up-regulates miR-21in an autocrine manner, contributes to the EMT induced by arsenite. These data define a link from inflammation to EMT in the arsenite-induced malignant transformation of HBE cells. This link, mediated through miRNAs, establishes a mechanism for arsenite-induced lung carcinogenesis. - Highlights: • Arsenite evokes IL-6 secretion. • IL-6 autocrine mediates STAT3 signaling and up-regulates miR-21expression. • Inflammation is involved in arsenite-induced EMT

  14. Suberoylanilide hydroxamic acid (SAHA) inhibits EGF-induced cell transformation via reduction of cyclin D1 mRNA stability

    International Nuclear Information System (INIS)

    Zhang, Jingjie; Ouyang, Weiming; Li, Jingxia; Zhang, Dongyun; Yu, Yonghui; Wang, York; Li, Xuejun; Huang, Chuanshu

    2012-01-01

    Suberoylanilide hydroxamic acid (SAHA) inhibiting cancer cell growth has been associated with its downregulation of cyclin D1 protein expression at transcription level or translation level. Here, we have demonstrated that SAHA inhibited EGF-induced Cl41 cell transformation via the decrease of cyclin D1 mRNA stability and induction of G0/G1 growth arrest. We found that SAHA treatment resulted in the dramatic inhibition of EGF-induced cell transformation, cyclin D1 protein expression and induction of G0/G1 growth arrest. Further studies showed that SAHA downregulation of cyclin D1 was only observed with endogenous cyclin D1, but not with reconstitutionally expressed cyclin D1 in the same cells, excluding the possibility of SAHA regulating cyclin D1 at level of protein degradation. Moreover, SAHA inhibited EGF-induced cyclin d1 mRNA level, whereas it did not show any inhibitory effect on cyclin D1 promoter-driven luciferase reporter activity under the same experimental conditions, suggesting that SAHA may decrease cyclin D1 mRNA stability. This notion was supported by the results that treatment of cells with SAHA decreased the half-life of cyclin D1 mRNA from 6.95 h to 2.57 h. Consistent with downregulation of cyclin D1 mRNA stability, SAHA treatment also attenuated HuR expression, which has been well-characterized as a positive regulator of cyclin D1 mRNA stability. Thus, our study identifies a novel mechanism responsible for SAHA inhibiting cell transformation via decreasing cyclin D1 mRNA stability and induction of G0/G1 growth arrest in Cl41 cells. -- Highlights: ► SAHA inhibits cell transformation in Cl41 cells. ► SAHA suppresses Cyclin D1 protein expression. ► SAHA decreases cyclin D1 mRNA stability.

  15. In vitro modeling of human pancreatic duct epithelial cell transformation defines gene expression changes induced by K-ras oncogenic activation in pancreatic carcinogenesis.

    Science.gov (United States)

    Qian, Jiaying; Niu, Jiangong; Li, Ming; Chiao, Paul J; Tsao, Ming-Sound

    2005-06-15

    Genetic analysis of pancreatic ductal adenocarcinomas and their putative precursor lesions, pancreatic intraepithelial neoplasias (PanIN), has shown a multistep molecular paradigm for duct cell carcinogenesis. Mutational activation or inactivation of the K-ras, p16(INK4A), Smad4, and p53 genes occur at progressive and high frequencies in these lesions. Oncogenic activation of the K-ras gene occurs in >90% of pancreatic ductal carcinoma and is found early in the PanIN-carcinoma sequence, but its functional roles remain poorly understood. We show here that the expression of K-ras(G12V) oncogene in a near diploid HPV16-E6E7 gene immortalized human pancreatic duct epithelial cell line originally derived from normal pancreas induced the formation of carcinoma in 50% of severe combined immunodeficient mice implanted with these cells. A tumor cell line established from one of these tumors formed ductal cancer when implanted orthotopically. These cells also showed increased activation of the mitogen-activated protein kinase, AKT, and nuclear factor-kappaB pathways. Microarray expression profiling studies identified 584 genes whose expression seemed specifically up-regulated by the K-ras oncogene expression. Forty-two of these genes have been reported previously as differentially overexpressed in pancreatic cancer cell lines or primary tumors. Real-time PCR confirmed the overexpression of a large number of these genes. Immunohistochemistry done on tissue microarrays constructed from PanIN and pancreatic cancer samples showed laminin beta3 overexpression starting in high-grade PanINs and occurring in >90% of pancreatic ductal carcinoma. The in vitro modeling of human pancreatic duct epithelial cell transformation may provide mechanistic insights on gene expression changes that occur during multistage pancreatic duct cell carcinogenesis.

  16. Epstein-Barr virus nuclear antigen 2 specifically induces expression of the B-cell activation antigen CD23

    International Nuclear Information System (INIS)

    Wang, F.; Gregory, C.D.; Rowe, M.; Rickinson, A.B.; Wang, D.; Birkenbach, M.; Kikutani, H.; Kishimoto, T.; Kieff, E.

    1987-01-01

    Epstein-Barr virus (EBV) infection of EBV-negative Burkitt lymphoma (BL) cells includes some changes similar to those seen in normal B lymphocytes that have been growth transformed by EBV. The role of individual EBV genes in this process was evaluated by introducing each of the viral genes that are normally expressed in EBV growth-transformed and latently infected lymphoblasts into an EBV-negative BL cell line, using recombinant retrovirus-mediated transfer. Clones of cells were derived that stably express the EBV nuclear antigen 1 (EBNA-1), EBNA-2, EBNA-3, EBNA-leader protein, or EBV latent membrane protein (LMP). These were compared with control clones infected with the retrovirus vector. All 10 clones converted to EBNA-2 expression differed from control clones or clones expressing other EBV proteins by growth in tight clumps and by markedly increased expression of one particular surface marker of B-cell activation, CD23. Other activation antigens were unaffected by EBNA-2 expression, as were markers already expressed on the parent BL cell line. The results indicate that EBNA-2 is a specific direct or indirect trans-activator of CD23. This establishes a link between an EBV gene and cell gene expression. Since CD23 has been implicated in the transduction of B-cell growth signals, its specific induction by EBNA-2 could be important in EBV induction of B-lymphocyte transformation

  17. Increased radiation-induced transformation in C3H/10T1/2 cells after transfer of an exogenous c-myc gene

    International Nuclear Information System (INIS)

    Sorrentino, V.; Drozdoff, V.; Zeitz, L.; Fleissner, E.

    1987-01-01

    C3H/10T 1/2 cells were infected with a retroviral vector expressing a mouse c-myc oncogene and a drug-selection marker. The resulting cells, morphologically indistinguishable from C3H/10T l/1, displayed a greatly enhanced sensitivity to neoplastic transformation by ionizing radiation or by a chemical carcinogen. Constitutive expression of myc therefore appears to synergize with an initial carcinogenic event, providing a function analogous to a subsequent event that apparently is required for the neoplastic transformation of these cells. This cell system should prove useful in exploring early stages in radiation-induced transformation

  18. Investigations of the functional states of dendritic cells under different conditioned microenvironments by Fourier transformed infrared spectroscopy.

    Science.gov (United States)

    Dong, Rong; Long, Jinhua; Xu, Xiaoli; Zhang, Chunlin; Wen, Zongyao; Li, Long; Yao, Weijuan; Zeng, Zhu

    2014-01-10

    Dendritic cells are potent and specialized antigen presenting cells, which play a crucial role in initiating and amplifying both the innate and adaptive immune responses. The dendritic cell-based vaccination against cancer has been clinically achieved promising successes. But there are still many challenges in its clinical application, especially for how to identify the functional states. The CD14+ monocytes were isolated from human peripheral blood after plastic adherence and purified to approximately 98% with cocktail immunomagnetic beads. The immature dendritic cells and mature dendritic cells were induced by traditional protocols. The resulting dendritic cells were cocultured with normal cells and cancer cells. The functional state of dendritic cells including immature dendritic cells (imDCs) and mature dendritic cells (mDCs) under different conditioned microenvironments were investigated by Fourier transformed infrared spectroscopy (FTIR) and molecular biological methods. The results of Fourier transformed infrared spectroscopy showed that the gene transcription activity and energy states of dendritic cells were specifically suppressed by tumor cells (P Fourier transformed infrared spectroscopy at given wave numbers were closely correlated with the expression levels of NF-κB (R2:0.69 and R2:0.81, respectively). Our results confirmed that the ratios of absorption intensities of Fourier transformed infrared spectroscopy at given wave numbers were positively correlated with the expression levels of NF-κB, suggesting that Fourier transformed infrared spectroscopy technology could be clinically applied to identify the functional states of dendritic cell when performing dendritic cell-based vaccination. It's significant for the simplification and standardization of dendritic cell-based vaccination clinical preparation protocols.

  19. Dual expression of Epstein-Barr virus, latent membrane protein-1 and human papillomavirus-16 E6 transform primary mouse embryonic fibroblasts through NF-κB signaling.

    Science.gov (United States)

    Shimabuku, Tetsuya; Tamanaha, Ayumi; Kitamura, Bunta; Tanabe, Yasuka; Tawata, Natsumi; Ikehara, Fukino; Arakaki, Kazunari; Kinjo, Takao

    2014-01-01

    The prevalence of Epstein-Barr virus (EBV) and high-risk human papilloma virus (HPV) infections in patients with oral cancer in Okinawa, southwest islands of Japan, has led to the hypothesis that carcinogenesis is related to EBV and HPV co-infection. To explore the mechanisms of transformation induced by EBV and HPV co-infection, we analyzed the transformation of primary mouse embryonic fibroblasts (MEFs) expressing EBV and HPV-16 genes, alone or in combination. Expression of EBV latent membrane protein-1 (LMP-1) alone or in combination with HPV-16 E6 increased cell proliferation and decreased apoptosis, whereas single expression of EBV nuclear antigen-1 (EBNA-1), or HPV-16 E6 did not. Co-expression of LMP-1 and E6 induced anchorage-independent growth and tumor formation in nude mice, whereas expression of LMP-1 alone did not. Although the singular expression of these viral genes showed increased DNA damage and DNA damage response (DDR), co-expression of LMP-1 and E6 did not induce DDR, which is frequently seen in cancer cells. Furthermore, co-expression of LMP-1 with E6 increased NF-κB signaling, and the knockdown of LMP-1 or E6 in co-expressing cells decreased cell proliferation, anchorage independent growth, and NF-κB activation. These data suggested that expression of individual viral genes is insufficient for inducing transformation and that co-expression of LMP-1 and E6, which is associated with suppression of DDR and increased NF-κB activity, lead to transformation. Our findings demonstrate the synergistic effect by the interaction of oncogenes from different viruses on the transformation of primary MEFs.

  20. Isorhapontigenin (ISO) inhibited cell transformation by inducing G0/G1 phase arrest via increasing MKP-1 mRNA Stability.

    Science.gov (United States)

    Gao, Guangxun; Chen, Liang; Li, Jingxia; Zhang, Dongyun; Fang, Yong; Huang, Haishan; Chen, Xiequn; Huang, Chuanshu

    2014-05-15

    The cancer chemopreventive property of Chinese herb new isolate isorhapontigenin (ISO) and mechanisms underlying its activity have never been explored. Here we demonstrated that ISO treatment with various concentrations for 3 weeks could dramatically inhibit TPA/EGF-induced cell transformation of Cl41 cells in Soft Agar assay, whereas co-incubation of cells with ISO at the same concentrations could elicit G0/G1 cell-cycle arrest without redundant cytotoxic effects on non-transformed cells. Further studies showed that ISO treatment resulted in cyclin D1 downregulation in dose- and time-dependent manner. Our results indicated that ISO regulated cyclin D1 at transcription level via targeting JNK/C-Jun/AP-1 activation. Moreover, we found that ISO-inhibited JNK/C-Jun/AP-1 activation was mediated by both upregulation of MKP-1 expression through increasing its mRNA stability and deactivating MKK7. Most importantly, MKP-1 knockdown could attenuate ISO-mediated suppression of JNK/C-Jun activation and cyclin D1 expression, as well as G0/G1 cell cycle arrest and cell transformation inhibition, while ectopic expression of FLAG-cyclin D1 T286A mutant also reversed ISO-induced G0/G1 cell-cycle arrest and inhibition of cell transformation. Our results demonstrated that ISO is a promising chemopreventive agent via upregulating mkp-1 mRNA stability, which is distinct from its cancer therapeutic effect with downregulation of XIAP and cyclin D1 expression.

  1. Cell-cell adhesion mediated by binding of membrane-anchored transforming growth factor α to epidermal growth factor receptors promotes cell proliferation

    International Nuclear Information System (INIS)

    Anklesaria, P.; Greenberger, J.S.; Teixido, J.; Laiho, M.; Massague, J.; Pierce, J.H.

    1990-01-01

    The precursor for transforming growth factor α, pro-TGF-α, is a cell surface glycoprotein that can establish contact with epidermal growth factor (EGF) receptors on adjacent cells. To examine whether the pro-TGF-α/EGF receptor pair can simultaneously mediate cell adhesion and promote cell proliferation, the authors have expressed pro-TGF-α in a bone marrow stromal cell line labeled with [ 35 S] cysteine. Expression of pro-TGF-α allows these cells to support long-term attachment of an EGF/interleukin-3-dependent hematopoietic progenitor cell line that expresses EGF receptors but is unable to adhere to normal stroma. This interaction is inhibited by soluble EGF receptor ligands. Further, the hematopoietic progenitor cells replicate their DNA while they are attached to the stromal cell layer and become foci of sustained cell proliferation. Thus, pro-TGF-α and the EGF receptor can function as mediators of intercellular adhesion and this interaction may promote a mitogenic response. They propose the term juxtacrine to designate this form of stimulation between adjacent cells

  2. Lactose/whey utilization and ethanol production by transformed Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Porro, D; Martegani, E; Ranzi, B M; Alberghina, L

    1992-04-05

    Strains of Saccharomyces cerevisiae transformed with a multicopy expression vector bearing both the Escherichia coli beta-galactosidase gene under the control of the upstream activating sequence of the GAL1-10 genes and the GAL4 activator gene release part of beta-galactosidase in the growth medium. This release is due to cell lysis of the older mother cells; the enzyme maintains its activity in buffered growth media. Fermentation studies with transformed yeast strains showed that the release of beta-galactosidase allowed an efficient growth on buffered media containing lactose as carbon source as well as on whey-based media. The transformed strains utilized up to 95% of the lactose and a high growth yield was obtained in rich media. High productions of ethanol were also observed in stationary phase after growth in lactose minimal media.

  3. High-risk human papillomavirus E7 expression reduces cell-surface MHC class I molecules and increases susceptibility to natural killer cells

    DEFF Research Database (Denmark)

    Bottley, G; Watherston, O G; Hiew, Y-L

    2007-01-01

    a role for E7 in tumour immune evasion. We show that knockdown of E7 expression in HPV16- and HPV18-transformed cervical carcinoma cells by RNA interference increased expression of major histocompatibility complex (MHC) class I at the cell surface and reduced susceptibility of these cells to natural...... killer (NK) cells. Tetracycline-regulated induction of HPV16 E7 resulted in reduced expression of cell surface MHC class I molecules and increased NK cell killing. Our results suggest that, for HPV-associated malignancies, reduced MHC class I expression is the result of an active immune evasion strategy...

  4. β-carotene and canthaxanthin inhibit chemically- and physically-induced transformation in 10T1/2 cells

    International Nuclear Information System (INIS)

    Pung, A.; Rundhaug, J.E.; Yoshizawa, C.N.; Bertram, J.S.

    1988-01-01

    We have studied the effects of β-carotene (β-C), a vitamin A precursor of plant origin, and canthaxanthin (CTX), a non-provitamin A carotenoid, on the neoplastic transformation of C3H/10T1/2 murine fibroblast cells. We show that both β-C and CTX inhibit 3-methylcholanthrene (MCA)-induced transformation. Both carotenoids failed to inhibit X-ray-induced transformation when the cells were treated prior to and during irradiation. However, when the drugs were added 1 week after X-irradiation and maintained in the medium thereafter, both carotenoids inhibited subsequent development of transformed foci in a dose-dependent manner. Again, CTX was more effective than β-C. The inhibition of MCA-induced transformation was reversible; upon removal of the drug, transformed foci developed within 2 weeks, indicating that the carotenoids were not specifically toxic to initiated cells. Although both carotenoids caused a small dose-dependent decrease in the growth rate of both parental and initiated 10T1/2 cells, they did not markedly affect colony size or number when the cells were treated as in the transformation assays, nor did they influence the expression of neoplasia of two transformed cell lines. We suggest that the carotenoids' lipid anti-oxidant properties may be responsible for their inhibitory actions on transformation. (author)

  5. Mammalian cell transformation: Mechanisms of carcinogenesis and assays for carcinogens

    International Nuclear Information System (INIS)

    Barrett, J.C.; Tennant, R.W.

    1985-01-01

    This book contains nine sections, each consisting of several papers. The section titles are: Molecular Changes in Cell Transformation; Differentiation, Growth Control, and Cell Transformation; Mutagenesis and Cell Transformation; Tumor Promotion and Cell Transformation; Mechanisms of Transformation of Human Fibroblasts; Mechanisms of Transformation of Epithelial Cells; Mechanisms of C 3 H 10T12 Cell Transformation; Mechanisms of Radiation-Induced Cell Transformation; and Use of Cell Transformation Assays for Carcinogen Testing

  6. Cloning of transgenic tobacco BY-2 cells; an efficient method to analyse and reduce high natural heterogeneity of transgene expression.

    Science.gov (United States)

    Nocarova, Eva; Fischer, Lukas

    2009-04-22

    Phenotypic characterization of transgenic cell lines, frequently used in plant biology studies, is complicated because transgene expression in individual cells is often heterogeneous and unstable. To identify the sources and to reduce this heterogeneity, we transformed tobacco (Nicotiana tabacum L.) BY-2 cells with a gene encoding green fluorescent protein (GFP) using Agrobacterium tumefaciens, and then introduced a simple cloning procedure to generate cell lines derived from the individual transformed cells. Expression of the transgene was monitored by analysing GFP fluorescence in the cloned lines and also in lines obtained directly after transformation. The majority ( approximately 90%) of suspension culture lines derived from calli that were obtained directly from transformation consisted of cells with various levels of GFP fluorescence. In contrast, nearly 50% of lines generated by cloning cells from the primary heterogeneous suspensions consisted of cells with homogenous GFP fluorescence. The rest of the lines exhibited "permanent heterogeneity" that could not be resolved by cloning. The extent of fluorescence heterogeneity often varied, even among genetically identical clones derived from the primary transformed lines. In contrast, the offspring of subsequent cloning of the cloned lines was uniform, showing GFP fluorescence intensity and heterogeneity that corresponded to the original clone. The results demonstrate that, besides genetic heterogeneity detected in some lines, the primary lines often contained a mixture of epigenetically different cells that could be separated by cloning. This indicates that a single integration event frequently results in various heritable expression patterns, which are probably accidental and become stabilized in the offspring of the primary transformed cells early after the integration event. Because heterogeneity in transgene expression has proven to be a serious problem, it is highly advisable to use transgenes tagged with

  7. STAT3-mediated constitutive expression of SOCS-3 in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Brender, C; Nielsen, M; Kaltoft, K

    2001-01-01

    ) obtained from affected skin from a patient with mycosis fungoides (MF) and from peripheral blood from a patient with Sezary syndrome (SS). In contrast, constitutive SOCS-3 expression is not found in the leukemic Jurkat T-cell line, the MOLT-4 acute lymphoblastic leukemia cell line, and the monocytic......, it has been hypothesized that an aberrant SOCS expression plays a role in neoplastic transformation. This study reports on a constitutive SOCS-3 expression in cutaneous T-cell lymphoma (CTCL) cell lines. SOCS-3 protein is constitutively expressed in tumor cell lines (but not in nonmalignant T cells...... leukemic cell line U937. Expression of SOCS-3 coincides with a constitutive activation of STAT3 in CTCL tumor cells, and stable transfection of CTCL tumor cells with a dominant negative STAT3 strongly inhibits SOCS-3 expression, whereas transfection with wild-type STAT3 does not. Moreover, the reduced SOCS...

  8. Functional transforming growth factor-β receptor type II expression by CD4+ T cells in Peyer's patches is essential for oral tolerance induction.

    Directory of Open Access Journals (Sweden)

    Rebekah S Gilbert

    Full Text Available Our previous studies have shown that Peyer's patches (PPs play a key role in the induction of oral tolerance. Therefore, we hypothesized that PPs are an important site for Transforming Growth Factor (TGF-β signaling and sought to prove that this tissue is of importance in oral tolerance induction. We found that expression of TGF-β type II receptor (TGFβRII by CD4(+ T cells increases and persists in the PPs of normal C57BL/6 mice after either high- or low-dose feeding of OVA when compared to mesenteric lymph nodes (MLNs and spleen. Approximately one-third of these TGFβRII(+ CD4(+ T cells express the transcription factor Foxp3. Interestingly, the number of TGFβRII(+ CD4(+ T cells in PPs decreased when OVA-fed mice were orally challenged with OVA plus native cholera toxin (CT. In contrast, numbers of TGFβRII(+ CD4(+ T cells were increased in the intestinal lamina propria (iLP of these challenged mice. Further, these PP CD4(+ TGFβRII(+ T cells upregulated Foxp3 within 2 hours after OVA plus CT challenge. Mice fed PBS and challenged with OVA plus CT did not reveal any changes in TGFβRII expression by CD4(+ T cells. In order to test the functional property of TGFβRII in the induction of oral tolerance, CD4dnTGFβRII transgenic mice, in which TGFβRII signaling is abrogated from all CD4(+ T cells, were employed. Importantly, these mice could not develop oral tolerance to OVA. Our studies show a critical, dose-independent, role for TGFβRII expression and function by CD4(+ T cells in the gut-associated lymphoid tissues, further underlining the vital role of PPs in oral tolerance.

  9. Oncomirs Expression Profiling in Uterine Leiomyosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Bruna Cristine de Almeida

    2017-12-01

    Full Text Available MicroRNAs (miRNAs are small non-coding RNAs that act as regulators of gene expression at the post-transcriptional level. They play a key role in several biological processes. Their abnormal expression may lead to malignant cell transformation. This study aimed to evaluate the expression profile of 84 miRNAs involved in tumorigenesis in immortalized cells of myometrium (MM, uterine leiomyoma (ULM, and uterine leiomyosarcoma (ULMS. Specific cell lines were cultured and qRT-PCR was performed. Thirteen miRNAs presented different expression profiles in ULM and the same thirteen in ULMS compared to MM. Eight miRNAs were overexpressed, and five were underexpressed in ULM. In ULMS cells, five miRNAs exhibited an overexpression and eight were down-regulated. Six miRNAs (miR-1-3p, miR-130b-3p, miR-140-5p, miR-202-3p, miR-205-5p, and miR-7-5p presented a similar expression pattern in cell lines compared to patient samples. Of these, only three miRNAs showed significant expression in ULM (miR-1-3p, miR-140-5p, and miR-7-5p and ULMS (miR-1-3p, miR-202-3p, and miR-7-5p. Our preliminary approach identified 24 oncomirs with an altered expression profile in ULM and ULMS cells. We identified four differentially expressed miRNAs with the same profile when compared with patients’ samples, which strongly interacted with relevant genes, including apoptosis regulator (BCL2, epidermal growth factor receptor (EGFR, vascular endothelial growth factor A (VEGFA, insulin like growth factor 1 receptor (IGF1R,serine/threonine kinase (RAF1, receptor tyrosine kinase (MET, and bHLH transcription factor (MYCN. This led to alterations in their mRNA-target.

  10. Down-regulation of a calmodulin-related gene during transformation of human mammary epithelial cells

    International Nuclear Information System (INIS)

    Yaswen, P.; Smoll, A.; Stampfer, M.R.; Peehl, D.M.; Trask, D.K.; Sager, R.

    1990-01-01

    A human cDNA library obtained from cultured normal mammary epithelial cells (HMECs) was searched by subtractive hybridization for genes whose decrease in expression might be relevant to epithelial transformation. One clone identified by this procedure corresponded to a 1.4 kilobase mRNA, designated NB-1, whose expression was decreased >50-fold in HMECs tumorigenically transformed in vitro after exposure to benzo[α]pyrene and Kirsten sarcoma virus. Sequence analysis of NB-1 cDNA revealed an open reading frame with a high degree of homology to calmodulin. NB-1 expression could be demonstrated by polymerase chain reaction amplification in normal breast, prostate, cervix, and epidermal tissues. The presence of NB-1 transcripts was variable in primary breast carcinoma tissues and undetectable in tumor-derived cell lines of breast, prostate, or other origins. NB-1 mRNA expression could be down-regulated in cultured HMECs by exposure to reconstituted extracellular matrix material, while exposure to transforming growth factor type β increased its relative abundance. The protein encoded by NB-1 may have Ca 2 plus binding properties and perform functions similar to those of authentic calmodulin. Its possible roles in differentiation and/or suppression of tumorigenicity in epithelial tissues remain to be examined

  11. MicroRNA-200b Suppresses Arsenic-transformed Cell Migration by Targeting Protein Kinase Cα and Wnt5b-Protein Kinase Cα Positive Feedback Loop and Inhibiting Rac1 Activation*

    Science.gov (United States)

    Wang, Zhishan; Humphries, Brock; Xiao, Hua; Jiang, Yiguo; Yang, Chengfeng

    2014-01-01

    MicroRNA-200b (miR-200b) is a member of miR-200 family that has been found to inhibit cell migration and cancer metastasis; however, the underlying mechanism is not well understood. We previously reported that miR-200 expression is depleted in arsenic-transformed human bronchial epithelial cells with highly migratory and invasive characteristics, whereas stably re-expressing miR-200b strongly suppresses arsenic-transformed cell migration. This study was performed to investigate how miR-200b inhibits arsenic-transformed cell migration. We found that protein kinase Cα (PKCα) is significantly up-regulated in arsenic-transformed cells. Combining bioinformatics analysis with PKCα 3′-untranslated region vector luciferase reporter assays, we showed that PKCα is a direct target of miR-200b. Inhibiting PKCα activity or knocking down PKCα expression drastically reduced cell migration, phenocoping the inhibitory effect of overexpressing miR-200b. In contrast, forced expression of PKCα in miR-200b overexpressing cells impaired the inhibitory effect of miR-200b on cell migration. In addition, we also found a positive feedback loop between Wnt5b and PKCα in arsenic-transformed cells. Knocking down Wnt5b expression reduced phospho-PKC levels and cell migration; and knocking down PKCα expression decreased Wnt5b level and cell migration. Moreover, forced expression of PKCα increased Wnt5b and phospho-PKC levels and cell migration. Further mechanistic studies revealed that Rac1 is highly activated in arsenic-transformed cells and stably expressing miR-200b abolishes Rac1 activation changing actin cytoskeleton organization. Manipulating PKCα or Wnt5b expression levels significantly altered the level of active Rac1. Together, these findings indicate that miR-200b suppresses arsenic-transformed cell migration by targeting PKCα and Wnt5b-PKCα positive feedback loop and subsequently inhibiting Rac1 activation. PMID:24841200

  12. MicroRNA-200b suppresses arsenic-transformed cell migration by targeting protein kinase Cα and Wnt5b-protein kinase Cα positive feedback loop and inhibiting Rac1 activation.

    Science.gov (United States)

    Wang, Zhishan; Humphries, Brock; Xiao, Hua; Jiang, Yiguo; Yang, Chengfeng

    2014-06-27

    MicroRNA-200b (miR-200b) is a member of miR-200 family that has been found to inhibit cell migration and cancer metastasis; however, the underlying mechanism is not well understood. We previously reported that miR-200 expression is depleted in arsenic-transformed human bronchial epithelial cells with highly migratory and invasive characteristics, whereas stably re-expressing miR-200b strongly suppresses arsenic-transformed cell migration. This study was performed to investigate how miR-200b inhibits arsenic-transformed cell migration. We found that protein kinase Cα (PKCα) is significantly up-regulated in arsenic-transformed cells. Combining bioinformatics analysis with PKCα 3'-untranslated region vector luciferase reporter assays, we showed that PKCα is a direct target of miR-200b. Inhibiting PKCα activity or knocking down PKCα expression drastically reduced cell migration, phenocoping the inhibitory effect of overexpressing miR-200b. In contrast, forced expression of PKCα in miR-200b overexpressing cells impaired the inhibitory effect of miR-200b on cell migration. In addition, we also found a positive feedback loop between Wnt5b and PKCα in arsenic-transformed cells. Knocking down Wnt5b expression reduced phospho-PKC levels and cell migration; and knocking down PKCα expression decreased Wnt5b level and cell migration. Moreover, forced expression of PKCα increased Wnt5b and phospho-PKC levels and cell migration. Further mechanistic studies revealed that Rac1 is highly activated in arsenic-transformed cells and stably expressing miR-200b abolishes Rac1 activation changing actin cytoskeleton organization. Manipulating PKCα or Wnt5b expression levels significantly altered the level of active Rac1. Together, these findings indicate that miR-200b suppresses arsenic-transformed cell migration by targeting PKCα and Wnt5b-PKCα positive feedback loop and subsequently inhibiting Rac1 activation. © 2014 by The American Society for Biochemistry and Molecular

  13. MET signalling in primary colon epithelial cells leads to increased transformation irrespective of aberrant Wnt signalling

    Science.gov (United States)

    Boon, E M J; Kovarikova, M; Derksen, P W B; van der Neut, R

    2005-01-01

    It has been shown that in hereditary and most sporadic colon tumours, components of the Wnt pathway are mutated. The Wnt target MET has been implicated in the development of colon cancer. Here, we show that overexpression of wild-type or a constitutively activated form of MET in colon epithelial cells leads to increased transformation irrespective of Wnt signalling. Fetal human colon epithelial cells without aberrant Wnt signalling were transfected with wild-type or mutated MET constructs. Expression of these constructs leads to increased phosphorylation of MET and its downstream targets PKB and MAPK. Upon stimulation with HGF, the expression of E-cadherin is downregulated in wild-type MET-transfected cells, whereas cells expressing mutated MET show low E-cadherin levels independent of stimulation with ligand. This implies a higher migratory propensity of these cells. Furthermore, fetal human colon epithelial cells expressing the mutated form of MET have colony-forming capacity in soft agar, while cells expressing wild-type MET show an intermediate phenotype. Subcutaneous injection of mutated MET-transfected cells in nude mice leads to the formation of tumours within 12 days in all mice injected. At this time point, mock-transfected cells do not form tumours, while wild-type MET-transfected cells form subcutaneous tumours in one out of five mice. We thus show that MET signalling can lead to increased transformation of colon epithelial cells independent of Wnt signalling and in this way could play an essential role in the onset and progression of colorectal cancer. PMID:15785735

  14. Structural requirements for cub domain containing protein 1 (CDCP1 and Src dependent cell transformation.

    Directory of Open Access Journals (Sweden)

    Gwendlyn Kollmorgen

    Full Text Available Cub domain containing protein 1 (CDCP1 is strongly expressed in tumors derived from lung, colon, ovary, or kidney. It is a membrane protein that is phosphorylated and then bound by Src family kinases. Although expression and phosphorylation of CDCP1 have been investigated in many tumor cell lines, the CDCP1 features responsible for transformation have not been fully evaluated. This is in part due to the lack of an experimental system in which cellular transformation depends on expression of exogenous CDCP1 and Src. Here we use retrovirus mediated co-overexpression of c-Src and CDCP1 to induce focus formation of NIH3T3 cells. Employing different mutants of CDCP1 we show that for a full transformation capacity, the intact amino- and carboxy-termini of CDCP1 are essential. Mutation of any of the core intracellular tyrosine residues (Y734, Y743, or Y762 abolished transformation, and mutation of a palmitoylation motif (C689,690G strongly reduced it. Src kinase binding to CDCP1 was not required since Src with a defective SH2 domain generated even more CDCP1 dependent foci whereas Src myristoylation was necessary. Taken together, the focus formation assay allowed us to define structural requirements of CDCP1/Src dependent transformation and to characterize the interaction of CDCP1 and Src.

  15. A novel rat fibrosarcoma cell line from transformed bone marrow-derived mesenchymal stem cells with maintained in vitro and in vivo stemness properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Meng-Yu [Department of Cell Therapy, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway); Nestvold, Janne, E-mail: j.m.nestvold@medisin.uio.no [Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo (Norway); Rekdal, Øystein [Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø (Norway); Kvalheim, Gunnar [Department of Cell Therapy, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway); Fodstad, Øystein [Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital, Oslo (Norway)

    2017-03-15

    Increasing evidence suggests a possible relationship between mesenchymal stem cells (MSCs) and sarcoma. MSCs are hypothesized to be the cells initiating sarcomagenesis, and cancer stem cells (CSCs) sharing features of MSCs have been identified in sarcomas. Here, we report on the characteristics of a bone marrow-derived rat mesenchymal stem cell line that spontaneously transformed in long-term culture. The rat transformed mesenchymal stem cells (rTMSCs) produced soft-tissue fibrosarcomas in immunocompromised mice and immunocompetent rats. In vitro, the rTMSCs displayed increased proliferation capacity compared to the untransformed cell line. The transformed MSCs maintained the mesenchymal phenotype by expression of the stem cell marker CD 90 and the lack of hematopoietic and endothelial markers. Cytogenetic analysis detected trisomy 6 in the rTMSCs. Side population (SP) isolation and tumorsphere cultivation of the transformed cells confirmed the presence of CSCs among the rTMSCs. Importantly, the rTMSCs retained their differentiation capacity towards osteogenic and adipogenic lineages. This transformed MSC-based cell line may be valuable in examining the balance in a mixed cell population between cancer stem cell properties and the ability to differentiate to specific non-transformed cell populations. Moreover, it may also be a useful tool to evaluate the efficacy of novel targeted immunotherapies in vivo. - Highlights: • Spontaneously transformed rat MSCs (rTMSCs) share characteristics with normal MSCs. • rTMSCs possess a side population, enriched with tumorigenic cells. • rTMSCs model fibrosarcoma in vivo.

  16. A novel rat fibrosarcoma cell line from transformed bone marrow-derived mesenchymal stem cells with maintained in vitro and in vivo stemness properties

    International Nuclear Information System (INIS)

    Wang, Meng-Yu; Nestvold, Janne; Rekdal, Øystein; Kvalheim, Gunnar; Fodstad, Øystein

    2017-01-01

    Increasing evidence suggests a possible relationship between mesenchymal stem cells (MSCs) and sarcoma. MSCs are hypothesized to be the cells initiating sarcomagenesis, and cancer stem cells (CSCs) sharing features of MSCs have been identified in sarcomas. Here, we report on the characteristics of a bone marrow-derived rat mesenchymal stem cell line that spontaneously transformed in long-term culture. The rat transformed mesenchymal stem cells (rTMSCs) produced soft-tissue fibrosarcomas in immunocompromised mice and immunocompetent rats. In vitro, the rTMSCs displayed increased proliferation capacity compared to the untransformed cell line. The transformed MSCs maintained the mesenchymal phenotype by expression of the stem cell marker CD 90 and the lack of hematopoietic and endothelial markers. Cytogenetic analysis detected trisomy 6 in the rTMSCs. Side population (SP) isolation and tumorsphere cultivation of the transformed cells confirmed the presence of CSCs among the rTMSCs. Importantly, the rTMSCs retained their differentiation capacity towards osteogenic and adipogenic lineages. This transformed MSC-based cell line may be valuable in examining the balance in a mixed cell population between cancer stem cell properties and the ability to differentiate to specific non-transformed cell populations. Moreover, it may also be a useful tool to evaluate the efficacy of novel targeted immunotherapies in vivo. - Highlights: • Spontaneously transformed rat MSCs (rTMSCs) share characteristics with normal MSCs. • rTMSCs possess a side population, enriched with tumorigenic cells. • rTMSCs model fibrosarcoma in vivo.

  17. Inverse relationship between TCTP/RhoA and p53/ /cyclin A/actin expression in ovarian cancer cells Inverse relationship between TCTP/RhoA and p53/ /cyclin A/actin expression in ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Malgorzata Kloc

    2012-10-01

    Full Text Available The translationally controlled tumor protein (TCTP plays a role in cell growth, cell cycle and cancer
    progression. TCTP controls negatively the stability of the p53 tumor suppressor protein and interacts with the
    cellular cytoskeleton. The deregulation of the actin and cytokeratin cytoskeleton is responsible for the increased
    migratory activity of tumor cells and is linked with poor patient outcome. Recent studies indicate that cyclin A,
    a key regulator of cell cycle, controls actin organization and negatively regulates cell motility via regulation of RhoA
    expression. We studied the organization of actin and cytokeratin cytoskeleton and the expression of TCTP, p53,
    cyclin A, RhoA and actin in HIO180 non-transformed ovarian epithelial cells, and OVCAR3 and SKOV3 (expressing
    low level of inducible p53 ovarian epithelial cancer cells with different metastatic potential. Immunostaining
    and ultrastructural analyses illustrated a dramatic difference in the organization of the cytokeratin and actin
    filaments in non-transformed versus cancer cell lines. We also determined that there is an inverse relationship between
    the level of TCTP/RhoA and actin/p53/cyclin A expression in ovarian cancer cell lines. This previously unidentified
    negative relationship between TCTP/RhoA and actin/p53/cyclin A may suggest that this interaction is linked
    with the high aggressiveness of ovarian cancers.The translationally controlled tumor protein (TCTP plays a role in cell growth, cell cycle and cancer
    progression. TCTP controls negatively the stability of the p53 tumor suppressor protein and interacts with the
    cellular cytoskeleton. The deregulation of the actin and cytokeratin cytoskeleton is responsible for the increased
    migratory activity of tumor cells and is linked with poor patient outcome. Recent studies indicate that cyclin A,
    a key regulator of cell cycle, controls actin organization

  18. Properties of HTLV-I transformed CD8+ T-cells in response to HIV-1 infection.

    Science.gov (United States)

    Gulzar, N; Shroff, A; Buberoglu, B; Klonowska, D; Kim, J E; Copeland, K F T

    2010-10-25

    HIV-1 infection studies of primary CD8(+) T-cells are hampered by difficulty in obtaining a significant number of targets for infection and low levels of productive infection. Further, there exists a paucity of CD8-expressing T-cell lines to address questions pertaining to the study of CD8(+) T-cells in the context of HIV-1 infection. In this study, a set of CD8(+) T-cell clones were originated through HTLV-I transformation in vitro, and the properties of these cells were examined. The clones were susceptible to T-cell tropic strains of the virus and exhibited HIV-1 production 20-fold greater than primary CD4(+) T-cells. Productive infection resulted in a decrease in expression of CD8 and CXCR4 molecules on the surface of the CD8(+) T-cell clones and antibodies to these molecules abrogated viral binding and replication. These transformed cells provide an important tool in the study of CD8(+) T-cells and may provide important insights into the mechanism(s) behind HIV-1 induced CD8(+) T-cell dysfunction. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Transient GFP expression in Nicotiana plumbaginifolia suspension cells: the role of gene silencing, cell death and T-DNA loss.

    Science.gov (United States)

    Weld, R; Heinemann, J; Eady, C

    2001-03-01

    The transient nature of T-DNA expression was studied with a gfp reporter gene transferred to Nicotiana plumbaginifolia suspension cells from Agrobacterium tumefaciens. Individual GFP-expressing protoplasts were isolated after 4 days' co-cultivation. The protoplasts were cultured without selection and 4 weeks later the surviving proto-calluses were again screened for GFP expression. Of the proto-calluses initially expressing GFP, 50% had lost detectable GFP activity during the first 4 weeks of culture. Multiple T-DNA copies of the gfp gene were detected in 10 of 17 proto-calluses lacking visible GFP activity. The remaining 7 cell lines contained no gfp sequences. Our results confirm that transiently expressed T-DNAs can be lost during growth of somatic cells and demonstrate that transiently expressing cells frequently integrate multiple T-DNAs that become silenced. In cells competent for DNA uptake, cell death and gene silencing were more important barriers to the recovery of stably expressing transformants than lack of T-DNA integration.

  20. Transforming growth factor-β1 promotes breast cancer metastasis by downregulating miR-196a-3p expression.

    Science.gov (United States)

    Chen, Yan; Huang, Shai; Wu, Bo; Fang, Jiankai; Zhu, Minsheng; Sun, Li; Zhang, Lifeng; Zhang, Yongsheng; Sun, Maomin; Guo, Lingling; Wang, Shouli

    2017-07-25

    Transforming growth factor-β1 is considered a key contributor to the progression of breast cancer. MicroRNAs are important factors in the development and progression of many malignancies. In the present study, upon studies of breast cancer cell lines and tissues, we showed that microRNA -196a-3p is decreased by transforming growth factor-β1 in breast cancer cells and associated with breast cancer progression. We identified neuropilin-2 as a target gene of microRNA -196a-3p and showed that it is regulated by transforming growth factor-β1. Moreover, transforming growth factor-β1-mediated inhibition of microRNA -196a-3p and activation of neuropilin-2were required for transforming growth factor-β1-induced migration and invasion of breast cancer cells. In addition, neuropilin-2 expression was suppressed in breast tumors, particularly in triple-negative breast cancers. Collectively, our findings strongly indicate that microRNA -196a-3p is a predictive biomarker of breast cancer metastasis and patient survival and a potential therapeutic target in metastatic breast cancer.

  1. Extracellular localization of catalase is associated with the transformed state of malignant cells.

    Science.gov (United States)

    Böhm, Britta; Heinzelmann, Sonja; Motz, Manfred; Bauer, Georg

    2015-12-01

    Oncogenic transformation is dependent on activated membrane-associated NADPH oxidase (NOX). However, the resultant extracellular superoxide anions are also driving the NO/peroxynitrite and the HOCl pathway, which eliminates NOX-expressing transformed cells through selective apoptosis induction. Tumor progression is dependent on dominant interference with intercellular apoptosis-inducing ROS signaling through membrane-associated catalase, which decomposes H2O2 and peroxynitrite and oxidizes NO. Particularly, the decomposition of extracellular peroxynitrite strictly requires membrane-associated catalase. We utilized small interfering RNA (siRNA)-mediated knockdown of catalase and neutralizing antibodies directed against the enzyme in combination with challenging H2O2 or peroxynitrite to determine activity and localization of catalase in cells from three distinct steps of multistage oncogenesis. Nontransformed cells did not generate extracellular superoxide anions and only showed intracellular catalase activity. Transformed cells showed superoxide anion-dependent intercellular apoptosis-inducing ROS signaling in the presence of suboptimal catalase activity in their membrane. Tumor cells exhibited tight control of intercellular apoptosis-inducing ROS signaling through a high local concentration of membrane-associated catalase. These data demonstrate that translocation of catalase to the outside of the cell membrane is already associated with the transformation step. A strong local increase in the concentration of membrane-associated catalase is achieved during tumor progression and is controlled by tumor cell-derived H2O2 and by transglutaminase.

  2. Challenge towards plant recombinant protein expression: instability in nuclear and chloroplast transformation

    Energy Technology Data Exchange (ETDEWEB)

    Amiri, M.; Jalali-Javaran, M.; Ehsani, P.; Haddad, R.

    2016-07-01

    It is crucial to maintain the stability of transgene and its expression level. It seems the transformation method and the target organ can influence this instability. To this aim, two transformation systems, Agrobacterium-mediated and particle bombardment systems which have been applied to introduce tissue plasminogen activator (tPA) into nuclear and chloroplast respectively, have been compared to determine transformation efficiency and tPA expression and stability. The presence of tPA gene in transformants has been confirmed by PCR analysis. The gene expression in nuclear transformants and homoplasmy in transplastomic plants have been assayed by ELISA and southern blot, respectively. Some of the Agrobacterium-derived transformants have shown the heritability and stability of the integrated T-DNA harboring the transgene which encodes the tissue plasminogen activator and instability of its expression in T1 generation. Using Southern blot analysis of bombardment-mediated transformants has surprisingly led to detecting the inheritability of tPA. There are several factors lead to silencing of transgene in transgenic plants which should be considered. Possible reasons for these silencing are like vector designing, methylation, copy number, and genome rearrangement.

  3. Challenge towards plant recombinant protein expression: instability in nuclear and chloroplast transformation

    International Nuclear Information System (INIS)

    Amiri, M.; Jalali-Javaran, M.; Ehsani, P.; Haddad, R.

    2016-01-01

    It is crucial to maintain the stability of transgene and its expression level. It seems the transformation method and the target organ can influence this instability. To this aim, two transformation systems, Agrobacterium-mediated and particle bombardment systems which have been applied to introduce tissue plasminogen activator (tPA) into nuclear and chloroplast respectively, have been compared to determine transformation efficiency and tPA expression and stability. The presence of tPA gene in transformants has been confirmed by PCR analysis. The gene expression in nuclear transformants and homoplasmy in transplastomic plants have been assayed by ELISA and southern blot, respectively. Some of the Agrobacterium-derived transformants have shown the heritability and stability of the integrated T-DNA harboring the transgene which encodes the tissue plasminogen activator and instability of its expression in T1 generation. Using Southern blot analysis of bombardment-mediated transformants has surprisingly led to detecting the inheritability of tPA. There are several factors lead to silencing of transgene in transgenic plants which should be considered. Possible reasons for these silencing are like vector designing, methylation, copy number, and genome rearrangement.

  4. Genetic transformation of tobacco NT1 cells with Agrobacterium tumefaciens.

    Science.gov (United States)

    Mayo, Kristin J; Gonzales, Barbara J; Mason, Hugh S

    2006-01-01

    This protocol is used to produce stably transformed tobacco (Nicotiana tabacum) NT1 cell lines, using Agrobacterium tumefaciens-mediated DNA delivery of a binary vector containing a gene encoding hepatitis B surface antigen and a gene encoding the kanamycin selection marker. The NT1 cultures, at the appropriate stage of growth, are inoculated with A. tumefaciens containing the binary vector. A 3-day cocultivation period follows, after which the cultures are rinsed and placed on solid selective medium. Transformed colonies ('calli') appear in approximately 4 weeks; they are subcultured until adequate material is obtained for analysis of antigen production. 'Elite' lines are selected based on antigen expression and growth characteristics. The time required for the procedure from preparation of the plant cell materials to callus development is approximately 5 weeks. Growth of selected calli to sufficient quantities for antigen screening may require 4-6 weeks beyond the initial selection. Creation of the plasmid constructs, transformation of the A. tumefaciens line, and ELISA and Bradford assays to assess protein production require additional time.

  5. Differential display technique of RNA from tumorigenic and non-tumorigenic variants of hamster cells transformed with avian sarcoma virus

    International Nuclear Information System (INIS)

    Leksa, V.; Altaner, C.

    1997-01-01

    Differential display technique was applied to study expression of RNA in tumorigenic and non-tumorigenic cell variants of avian sarcoma virus transformed hamster cells. Methodical conditions were worked out, which allowed identifying a cDNA fragment of an unknown gene expressed in non-tumorigenic cell variant only. Its role in tumor suppression remains to be determined. (author)

  6. Role of reactive oxygen species in arsenic-induced transformation of human lung bronchial epithelial (BEAS-2B) cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhuo, E-mail: zhuo.zhang@uky.edu [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok [Center for Research on Environmental Diseases, University of Kentucky, Lexington, KY 40536 (United States); Kim, Donghern [Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536 (United States); Shi, Xianglin [Center for Research on Environmental Diseases, University of Kentucky, Lexington, KY 40536 (United States)

    2015-01-09

    Highlights: • Short term exposure of cells to arsenic causes ROS generation. • Chronical exposure of cells to arsenic causes malignant cell transformation. • Inhibition of ROS generation reduces cell transformation by arsenic. • Arsenic-transformed cells exhibit reduced capacity of generating ROS. • Arsenic-transformed cells exhibit increased levels of antioxidants. - Abstract: Arsenic is an environmental carcinogen, its mechanisms of carcinogenesis remain to be investigated. Reactive oxygen species (ROS) are considered to be important. A previous study (Carpenter et al., 2011) has measured ROS level in human lung bronchial epithelial (BEAS-2B) cells and arsenic-transformed BEAS-2B cells and found that ROS levels were higher in transformed cells than that in parent normal cells. Based on these observations, the authors concluded that cell transformation induced by arsenic is mediated by increased cellular levels of ROS. This conclusion is problematic because this study only measured the basal ROS levels in transformed and parent cells and did not investigate the role of ROS in the process of arsenic-induced cell transformation. The levels of ROS in arsenic-transformed cells represent the result and not the cause of cell transformation. Thus question concerning whether ROS are important in arsenic-induced cell transformation remains to be answered. In the present study, we used expressions of catalase (antioxidant against H{sub 2}O{sub 2}) and superoxide dismutase 2 (SOD2, antioxidant against O{sub 2}{sup ·−}) to decrease ROS level and investigated their role in the process of arsenic-induced cell transformation. Our results show that inhibition of ROS by antioxidant enzymes decreased arsenic-induced cell transformation, demonstrating that ROS are important in this process. We have also shown that in arsenic-transformed cells, ROS generation was lower and levels of antioxidants are higher than those in parent cells, in a disagreement with the previous

  7. Role of reactive oxygen species in arsenic-induced transformation of human lung bronchial epithelial (BEAS-2B) cells

    International Nuclear Information System (INIS)

    Zhang, Zhuo; Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok; Kim, Donghern; Shi, Xianglin

    2015-01-01

    Highlights: • Short term exposure of cells to arsenic causes ROS generation. • Chronical exposure of cells to arsenic causes malignant cell transformation. • Inhibition of ROS generation reduces cell transformation by arsenic. • Arsenic-transformed cells exhibit reduced capacity of generating ROS. • Arsenic-transformed cells exhibit increased levels of antioxidants. - Abstract: Arsenic is an environmental carcinogen, its mechanisms of carcinogenesis remain to be investigated. Reactive oxygen species (ROS) are considered to be important. A previous study (Carpenter et al., 2011) has measured ROS level in human lung bronchial epithelial (BEAS-2B) cells and arsenic-transformed BEAS-2B cells and found that ROS levels were higher in transformed cells than that in parent normal cells. Based on these observations, the authors concluded that cell transformation induced by arsenic is mediated by increased cellular levels of ROS. This conclusion is problematic because this study only measured the basal ROS levels in transformed and parent cells and did not investigate the role of ROS in the process of arsenic-induced cell transformation. The levels of ROS in arsenic-transformed cells represent the result and not the cause of cell transformation. Thus question concerning whether ROS are important in arsenic-induced cell transformation remains to be answered. In the present study, we used expressions of catalase (antioxidant against H 2 O 2 ) and superoxide dismutase 2 (SOD2, antioxidant against O 2 ·− ) to decrease ROS level and investigated their role in the process of arsenic-induced cell transformation. Our results show that inhibition of ROS by antioxidant enzymes decreased arsenic-induced cell transformation, demonstrating that ROS are important in this process. We have also shown that in arsenic-transformed cells, ROS generation was lower and levels of antioxidants are higher than those in parent cells, in a disagreement with the previous report. The

  8. Biolistic transformation of tobacco and maize suspension cells using bacterial cells as microprojectiles.

    Science.gov (United States)

    Rasmussen, J L; Kikkert, J R; Roy, M K; Sanford, J C

    1994-01-01

    We have used both Escherichia coli cells and Agrobacterium tumefaciens cells as microprojectiles to deliver DNA into suspension-cultured tobacco (Nicotiana tabacum L. line NT1) cells using a helium powered biolistic device. In addition, E. coli cells were used as microprojectiles for the transformation of suspension-cultured maize (Zea mays cv. Black Mexican Sweet) cells. Pretreating the bacterial cells with phenol at a concentration of 1.0%, and combining the bacterial cells with tungsten particles increased the rates of transformation. In N. tabacum, we obtained hundreds of transient transformants per bombardment, but were unable to recover any stable transformants. In Z. mays we obtained thousands of transient transformants and an average of six stable transformants per bombardment. This difference is discussed.

  9. Transforming growth factor beta-1 expression in macrophages of human chronic periapical diseases.

    Science.gov (United States)

    Liang, Z-Z; Li, J; Huang, S-G

    2017-03-30

    The objective of this study was to observe the distribution of macrophages (MPs) expressing transforming growth factor beta-1 (TGF-β1) in tissue samples from patients with different human chronic periapical diseases. In this study, samples were collected from 75 volunteers, who were divided into three groups according to classified standards, namely, healthy control (N = 25), periapical granuloma (N = 25), and periapical cyst (N = 25). The samples were fixed in 10% buffered formalin for more than 48 h, dehydrated, embedded, and stained with hematoxylin and eosin for histopathology. Double immunofluorescence was conducted to analyze the expression of TGF-β-CD14 double-positive MPs in periapical tissues. The number of double-positive cells (cells/mm 2 ) were significantly higher in the chronic periapical disease tissues (P periapical cyst group than in the periapical granuloma group (P periapical diseases. The TGF-β1-CD14 double-positive cells might play an important role in the pathology of human chronic periapical diseases.

  10. Suppression of X-ray induced transformation by vitamin E in mouse C3H/10T1/2 cells

    International Nuclear Information System (INIS)

    Radner, B.S.; Kennedy, A.R.

    1986-01-01

    Vitamin E (d-α-tocopherol) was shown to decrease X-ray induced transformation in mouse C3H/10 1/2 cells. The d-α-tocopherol was active in the form of succinate diluted in ethanol, but was inactive at the highest non-toxic concentration of the pure substance dissolved in oil and diluted in acetone. Vitamin E succinate was effective when present only for the early portion of the radiation transformation assay period, indicating that its effect may be reversible. Vitamin E did not supress the growth and expression of transformed C3H/10 1/2 cells as foci when transformed cells were surrounded by a monolayer of normal cells. (author)

  11. Pre-micro RNA signatures delineate stages of endothelial cell transformation in Kaposi sarcoma.

    Directory of Open Access Journals (Sweden)

    Andrea J O'Hara

    2009-04-01

    Full Text Available MicroRNAs (miRNA have emerged as key regulators of cell lineage differentiation and cancer. We used precursor miRNA profiling by a novel real-time QPCR method (i to define progressive stages of endothelial cell transformation cumulating in Kaposi sarcoma (KS and (ii to identify specific miRNAs that serve as biomarkers for tumor progression. We were able to compare primary patient biopsies to well-established culture and mouse tumor models. Loss of mir-221 and gain of mir-15 expression demarked the transition from merely immortalized to fully tumorigenic endothelial cells. Mir-140 and Kaposi sarcoma-associated herpesvirus viral miRNAs increased linearly with the degree of transformation. Mir-24 emerged as a biomarker specific for KS.

  12. Neuropilin-2 induced by transforming growth factor-β augments migration of hepatocellular carcinoma cells

    International Nuclear Information System (INIS)

    Wittmann, Philipp; Grubinger, Markus; Gröger, Christian; Huber, Heidemarie; Sieghart, Wolfgang; Peck-Radosavljevic, Markus; Mikulits, Wolfgang

    2015-01-01

    Hepatocellular carcinoma (HCC) is the most common form of liver cancer and the third most lethal cancer worldwide. The epithelial to mesenchymal transition (EMT) describes the transformation of well-differentiated epithelial cells to a de-differentiated phenotype and plays a central role in the invasion and intrahepatic metastasis of HCC cells. Modulation of the transforming growth factor-β (TGF-β) signaling is known to induce various tumor-promoting and EMT-inducing pathways in HCC. The meta-analysis of a panel of EMT gene expression studies revealed that neuropilin 2 (NRP2) is significantly upregulated in cells that have undergone EMT induced by TGF-β. In this study we assessed the functional role of NRP2 in epithelial and mesenchymal-like HCC cells and focused on the molecular interplay between NRP2 and TGF-β/Smad signaling. NRP2 expression was analyzed in human HCC cell lines and tissue arrays comprising 133 HCC samples. Cell migration was examined by wound healing and Transwell assays in the presence and absence of siRNA against NRP2. NRP2 and TGF-β signaling were analyzed by Western blotting and confocal immunofluorescence microscopy. We show that NRP2 is particularly expressed in HCC cell lines with a dedifferentiated, mesenchymal-like phenotype. NRP2 expression is upregulated by the canonical TGF-β/Smad signaling while NRP2 expression has no impact on TGF-β signaling in HCC cells. Reduced expression of NRP2 by knock-down or inhibition of TGF-β signaling resulted in diminished cell migration independently of each other, suggesting that NRP2 fails to collaborate with TGF-β signaling in cell movement. In accordance with these data, elevated levels of NRP2 correlated with a higher tumor grade and less differentiation in a large collection of human HCC specimens. These data suggest that NRP2 associates with a less differentiated, mesenchymal-like HCC phenotype and that NRP2 plays an important role in tumor cell migration upon TGF-β-dependent HCC

  13. Malignant transformation of colonic epithelial cells by a colon-derived long noncoding RNA

    International Nuclear Information System (INIS)

    Franklin, Jeffrey L.; Rankin, Carl R.; Levy, Shawn; Snoddy, Jay R.; Zhang, Bing; Washington, Mary Kay; Thomson, J. Michael; Whitehead, Robert H.; Coffey, Robert J.

    2013-01-01

    Highlights: •Non-coding RNAs are found in the colonic crypt progenitor compartment. •Colonocytes transformed by ncNRFR are highly invasive and metastatic. •ncNRFR has a region similar to the miRNA, let-7 family. •ncNRFR expression alters let-7 activity as measured by reporter construct. •ncNRFR expression upregulates let-7b targets. -- Abstract: Recent progress has been made in the identification of protein-coding genes and miRNAs that are expressed in and alter the behavior of colonic epithelia. However, the role of long non-coding RNAs (lncRNAs) in colonic homeostasis is just beginning to be explored. By gene expression profiling of post-mitotic, differentiated tops and proliferative, progenitor-compartment bottoms of microdissected adult mouse colonic crypts, we identified several lncRNAs more highly expressed in crypt bottoms. One identified lncRNA, designated non-coding Nras functional RNA (ncNRFR), resides within the Nras locus but appears to be independent of the Nras coding transcript. Stable overexpression of ncNRFR in non-transformed, conditionally immortalized mouse colonocytes results in malignant transformation, as determined by growth in soft agar and formation of highly invasive tumors in nude mice. Moreover, ncNRFR appears to inhibit the function of the tumor suppressor let-7. These results suggest precise regulation of ncNRFR is necessary for proper cell growth in the colonic crypt, and its misregulation results in neoplastic transformation

  14. Role of Pin1 in UVA-induced cell proliferation and malignant transformation in epidermal cells

    International Nuclear Information System (INIS)

    Han, Chang Yeob; Hien, Tran Thi; Lim, Sung Chul; Kang, Keon Wook

    2011-01-01

    Highlights: → Pin1 expression is enhanced by low energy UVA irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. → UVA irradiation increases activator protein-1 activity and cyclin D1 in a Pin1-dependent manner. → UVA potentiates EGF-inducible, anchorage-independent growth of epidermal cells, and this is suppressed by Pin1 inhibition or by anti-oxidant. -- Abstract: Ultraviolet A (UVA) radiation (λ = 320-400 nm) is considered a major cause of human skin cancer. Pin1, a peptidyl prolyl isomerase, is overexpressed in most types of cancer tissues and plays an important role in cell proliferation and transformation. Here, we demonstrated that Pin1 expression was enhanced by low energy UVA (300-900 mJ/cm 2 ) irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. Exposure of epidermal cells to UVA radiation increased cell proliferation and cyclin D1 expression, and these changes were blocked by Pin1 inhibition. UVA irradiation also increased activator protein-1 (AP-1) minimal reporter activity and nuclear levels of c-Jun, but not c-Fos, in a Pin1-dependent manner. The increases in Pin1 expression and in AP-1 reporter activity in response to UVA were abolished by N-acetylcysteine (NAC) treatment. Finally, we found that pre-exposure of JB6 C141 cells to UVA potentiated EGF-inducible, anchorage-independent growth, and this effect was significantly suppressed by Pin1inhibition or by NAC.

  15. Spontaneously immortalised bovine mammary epithelial cells exhibit a distinct gene expression pattern from the breast cancer cells

    Directory of Open Access Journals (Sweden)

    Li Qianqian

    2010-10-01

    Full Text Available Abstract Background Spontaneous immortalisation of cultured mammary epithelial cells (MECs is an extremely rare event, and the molecular mechanism behind spontaneous immortalisation of MECs is unclear. Here, we report the establishment of a spontaneously immortalised bovine mammary epithelial cell line (BME65Cs and the changes in gene expression associated with BME65Cs cells. Results BME65Cs cells maintain the general characteristics of normal mammary epithelial cells in morphology, karyotype and immunohistochemistry, and are accompanied by the activation of endogenous bTERT (bovine Telomerase Reverse Transcriptase and stabilisation of the telomere. Currently, BME65Cs cells have been passed for more than 220 generations, and these cells exhibit non-malignant transformation. The expression of multiple genes was investigated in BME65Cs cells, senescent BMECs (bovine MECs cells, early passage BMECs cells and MCF-7 cells (a human breast cancer cell line. In comparison with early passage BMECs cells, the expression of senescence-relevant apoptosis-related gene were significantly changed in BME65Cs cells. P16INK4a was downregulated, p53 was low expressed and Bax/Bcl-2 ratio was reversed. Moreover, a slight upregulation of the oncogene c-Myc, along with an undetectable level of breast tumor-related gene Bag-1 and TRPS-1, was observed in BME65Cs cells while these genes are all highly expressed in MCF-7. In addition, DNMT1 is upregulated in BME65Cs. These results suggest that the inhibition of both senescence and mitochondrial apoptosis signalling pathways contribute to the immortality of BME65Cs cells. The expression of p53 and p16INK4a in BME65Cs was altered in the pattern of down-regulation but not "loss", suggesting that this spontaneous immortalization is possibly initiated by other mechanism rather than gene mutation of p53 or p16INK4a. Conclusions Spontaneously immortalised BME65Cs cells maintain many characteristics of normal BMEC cells and

  16. Extensive gene-specific translational reprogramming in a model of B cell differentiation and Abl-dependent transformation.

    Directory of Open Access Journals (Sweden)

    Jamie G Bates

    Full Text Available To what extent might the regulation of translation contribute to differentiation programs, or to the molecular pathogenesis of cancer? Pre-B cells transformed with the viral oncogene v-Abl are suspended in an immortalized, cycling state that mimics leukemias with a BCR-ABL1 translocation, such as Chronic Myelogenous Leukemia (CML and Acute Lymphoblastic Leukemia (ALL. Inhibition of the oncogenic Abl kinase with imatinib reverses transformation, allowing progression to the next stage of B cell development. We employed a genome-wide polysome profiling assay called Gradient Encoding to investigate the extent and potential contribution of translational regulation to transformation and differentiation in v-Abl-transformed pre-B cells. Over half of the significantly translationally regulated genes did not change significantly at the level of mRNA abundance, revealing biology that might have been missed by measuring changes in transcript abundance alone. We found extensive, gene-specific changes in translation affecting genes with known roles in B cell signaling and differentiation, cancerous transformation, and cytoskeletal reorganization potentially affecting adhesion. These results highlight a major role for gene-specific translational regulation in remodeling the gene expression program in differentiation and malignant transformation.

  17. Human T cell leukemia virus type I prevents cell surface expression of the T cell receptor through down-regulation of the CD3-gamma, -delta, -epsilon, and -zeta genes

    NARCIS (Netherlands)

    de Waal Malefyt, R.; Yssel, H.; Spits, H.; de Vries, J. E.; Sancho, J.; Terhorst, C.; Alarcon, B.

    1990-01-01

    Infection and transformation by human T cell leukemia virus type I (HTLV-I) up-regulates expression of several inducible genes including those coding for cytokines involved in the proliferation of normal and leukemic T cells. We demonstrate that HTLV-I can also shut off expression of the CD3-gamma,

  18. Pre-crisis mouse cells show strain-specific covariation in the amount of 54-kilodalton phosphoprotein and in susceptibility to transformation by simian virus 40.

    Science.gov (United States)

    Chen, S; Blanck, G; Pollack, R E

    1983-09-01

    We have used several inbred mouse strains to examine the role of the 54-kilodalton (kDa) cellular phosphoprotein in transformation by the papovavirus simian virus 40. We have measured the endogenous 54-kDa phosphoprotein in cells obtained from these inbred mouse strains. To study the effect of passage, cell cultures were measured for amount of the 54-kDa phosphoprotein at the 2nd and 12th passages. In the absence of any transforming agent, the amount of endogenous 54-kDa phosphoprotein in early pre-crisis mouse cells varied in a strain-specific way. Transformation frequency varied coordinately with endogenous 54-kDa expression. Mouse strains whose cells produced a high level of endogenous 54-kDa phosphoprotein on passage did not further increase its expression after simian virus 40 transformation.

  19. Relationship between X-ray exposure and malignant transformation in C3H 10T1/2 cells

    International Nuclear Information System (INIS)

    Kennedy, A.R.; Fox, M.; Murphy, G.; Little, J.B.

    1980-01-01

    The appearance of transformed foci after x-irradiation of the C3H 10T1/2 line of murine cells requires extensive proliferation followed by prolonged incubation under conditions of confluence. When the progeny of irradiated cells are resuspended and plated to determine the number of potential transformed foci, the absolute yield is constant over a wide range of dilutions and is similar to that observed in cultures that have not been resuspended. In addition, for cells exposed to a given x-ray dose, the number of transformed foci per dish is independent of the number of irradiated cells. These observations suggest that few, if any, of the transformed clones occur as a direct consequence of the x-ray exposure and challenge the hypothesis that transformed foci are the clonal products of occasional cells that have experienced an x-ray-induced mutational change. Rather, it appears that at least two steps are involved. We suggest that exposure to x-rays results in a change, for example, the induction or expression of some cell function, in many or all of the cells and that this change is transmitted to the progeny of the surviving cells; a consequence of this change is an enhanced probability of the occurrence of a second step, transformation, when these cells are maintained under conditions of confluence

  20. Adenovirus E1A/E1B Transformed Amniotic Fluid Cells Support Human Cytomegalovirus Replication

    Directory of Open Access Journals (Sweden)

    Natascha Krömmelbein

    2016-02-01

    Full Text Available The human cytomegalovirus (HCMV replicates to high titers in primary human fibroblast cell cultures. A variety of primary human cells and some tumor-derived cell lines do also support permissive HCMV replication, yet at low levels. Cell lines established by transfection of the transforming functions of adenoviruses have been notoriously resistant to HCMV replication and progeny production. Here, we provide first-time evidence that a permanent cell line immortalized by adenovirus type 5 E1A and E1B (CAP is supporting the full HCMV replication cycle and is releasing infectious progeny. The CAP cell line had previously been established from amniotic fluid cells which were likely derived from membranes of the developing fetus. These cells can be grown under serum-free conditions. HCMV efficiently penetrated CAP cells, expressed its immediate-early proteins and dispersed restrictive PML-bodies. Viral DNA replication was initiated and viral progeny became detectable by electron microscopy in CAP cells. Furthermore, infectious virus was released from CAP cells, yet to lower levels compared to fibroblasts. Subviral dense bodies were also secreted from CAP cells. The results show that E1A/E1B expression in transformed cells is not generally repressive to HCMV replication and that CAP cells may be a good substrate for dense body based vaccine production.

  1. Generation and characterization of p53 null transformed hepatic progenitor cells: oval cells give rise to hepatocellular carcinoma.

    Science.gov (United States)

    Dumble, Melissa L; Croager, Emma J; Yeoh, George C T; Quail, Elizabeth A

    2002-03-01

    Oval cells are bipotential liver stem cells able to differentiate into hepatocytes and bile duct epithelia. In normal adult liver oval cells are quiescent, existing in low numbers around the periportal region, and proliferate following severe, prolonged liver trauma. There is evidence implicating oval cells in the development of hepatocellular carcinoma, and hence the availability of an immortalized oval cell line would be invaluable for the study of liver cell lineage differentiation and carcinogenesis. A novel approach in the generation of cell lines is the use of the p53 knockout mouse. Absence of p53 allows a cell to cycle past the normal Hayflick limit, rendering it immortalized, although subsequent genetic alterations are thought necessary for transformation. p53 knockout mice were fed a choline-deficient, ethionine-supplemented diet, previously shown to increase oval cell numbers in wild-type mice. The oval cells were isolated by centrifugal elutriation and maintained in culture. Colonies of hepatic cells were isolated and characterized with respect to phenotype, growth characteristics and tumorigenicity. Analysis of gene expression by Northern blotting and immunocytochemistry suggests they are oval-like cells by virtue of albumin and transferrin expression, as well as the oval cell markers alpha fetoprotein, M(2)-pyruvate kinase and A6. Injection into athymic nude mice shows the cell lines are capable of forming tumors which phenotypically resemble hepatocellular carcinoma. Thus, the use of p53 null hepatic cells successfully generated immortalized and tumorigenic hepatic stem cell lines. The results presented support the idea that deleting p53 allows immortalization and contributes to the transformation of the oval-like cell lines. Further, the tumorigenic status of the cell lines is direct evidence for the participation of oval cells in the formation of hepatocellular carcinoma.

  2. Knockdown of AMPKα decreases ATM expression and increases radiosensitivity under hypoxia and nutrient starvation in an SV40-transformed human fibroblast cell line, LM217.

    Science.gov (United States)

    Murata, Yasuhiko; Hashimoto, Takuma; Urushihara, Yusuke; Shiga, Soichiro; Takeda, Kazuya; Jingu, Keiichi; Hosoi, Yoshio

    2018-01-22

    Presence of unperfused regions containing cells under hypoxia and nutrient starvation contributes to radioresistance in solid human tumors. It is well known that hypoxia causes cellular radioresistance, but little is known about the effects of nutrient starvation on radiosensitivity. We have reported that nutrient starvation induced decrease of mTORC1 activity and decrease of radiosensitivity in an SV40-transformed human fibroblast cell line, LM217, and that nutrient starvation induced increase of mTORC1 activity and increase of radiosensitivity in human liver cancer cell lines, HepG2 and HuH6 (Murata et al., BBRC 2015). Knockdown of mTOR using small interfering RNA (siRNA) for mTOR suppressed radiosensitivity under nutrient starvation alone in HepG2 cells, which suggests that mTORC1 pathway regulates radiosensitivity under nutrient starvation alone. In the present study, effects of hypoxia and nutrient starvation on radiosensitivity were investigated using the same cell lines. LM217 and HepG2 cells were used to examine the effects of hypoxia and nutrient starvation on cellular radiosensitivity, mTORC1 pathway including AMPK, ATM, and HIF-1α, which are known as regulators of mTORC1 activity, and glycogen storage, which is induced by HIF-1 and HIF-2 under hypoxia and promotes cell survival. Under hypoxia and nutrient starvation, AMPK activity and ATM expression were increased in LM217 cells and decreased in HepG2 cells compared with AMPK activity under nutrient starvation alone or ATM expression under hypoxia alone. Under hypoxia and nutrient starvation, radiosensitivity was decreased in LM217 cells and increased in HepG2 cells compared with radiosensitivity under hypoxia alone. Under hypoxia and nutrient starvation, knockdown of AMPK decreased ATM activity and increased radiation sensitivity in LM217 cells. In both cell lines, mTORC1 activity was decreased under hypoxia and nutrient starvation. Under hypoxia alone, knockdown of mTOR slightly increased ATM

  3. [Bendamustine-rituximab therapy is effective for transformed follicular lymphoma with significant expression of p53].

    Science.gov (United States)

    Kuroda, Hiroyuki; Jomen, Wataru; Miura, Shogo; Arihara, Yohei; Yamada, Michiko; Hirako, Tasuku; Abe, Tomoyuki; Sakurai, Tamaki; Fujii, Shigeyuki; Maeda, Masahiro; Fujita, Miri; Nagashima, Kazuo; Okagawa, Yutaka; Hoki, Toshifumi; Kato, Junji

    2013-08-01

    We describe a patient with transformed follicular lymphoma(FL), expressing p53 but remaining in complete remission(CR) due to bendamustine-rituximab(BR)therapy. She was a 64-year-old female diagnosed with stage IV FL(grade 3A)in July 2007 when she was admitted with right lower abdominal pain and body weight loss. Colonoscopy revealed Bauhin' valve lymphoma of the terminal ileum, and computed tomography(CT)scan showed lymphadenopathy, involving the cervical, mediastinal para-aortic lymph nodes and right tonsil. She received chemotherapy with eight courses of CHOP therapy with rituximab and achieved CR. Two and a half years later, mediastinal lymph node swelling relapsed, and ibritumomab tiuxetan therapy induced the second CR. After ten months, however, a third relapse occurred as a submucosal tumor(SMT)of the stomach. Gastric SMT biopsy showed diffuse large B cell lymphoma(DLBCL)transformation with immunohistochemical expression of p53. Although gastric SMT disappeared after radiotherapy, which achieved the third CR, lymph node swelling was detected again in the para-aortic and-iliac artery lymph nodes in September 2011. Subsequently, she was treated with five courses of BR therapy, because bendamustine had been reported to be effective for p53 gene-deficient B cell neoplasms. The therapy was successful and achieved the fourth CR, demonstrating that BR therapy was effective for p53-expressing DLBCL.

  4. Some characteristics of neoplastic cell transformation in transgenic mice.

    Science.gov (United States)

    Shvemberger, I N; Ermilov, A N

    1996-01-01

    The role of the expression of different cellular genes and viral oncogenes in malignant cell transformation is discussed. We pay special attention to the role of the genes for growth factors and their receptors and homeobox genes in oncogenesis. Based on both the literature and our own data, specific features of tumors developed in transgenic mice are discussed. All of these data are used to analyze current theories of multistep oncogenesis and the stochastic component in this process. We suggest that all known evidence about the mechanisms of oncogenesis be used in studying the problem at various structural and functional levels in an organism. The chapter shows that transgenic mice are a most suitable model for studying various aspects of malignant transformation from the molecular to the organismal and populational levels.

  5. Activated platelet-derived growth factor autocrine pathway drives the transformed phenotype of a human glioblastoma cell line.

    Science.gov (United States)

    Vassbotn, F S; Ostman, A; Langeland, N; Holmsen, H; Westermark, B; Heldin, C H; Nistér, M

    1994-02-01

    Human glioblastoma cells (A172) were found to concomitantly express PDGF-BB and PDGF beta-receptors. The receptors were constitutively autophosphorylated in the absence of exogenous ligand, suggesting the presence of an autocrine PDGF pathway. Neutralizing PDGF antibodies as well as suramin inhibited the autonomous PDGF receptor tyrosine kinase activity and resulted in up-regulation of receptor protein. The interruption of the autocrine loop by the PDGF antibodies reversed the transformed phenotype of the glioblastoma cell, as determined by (1) diminished DNA synthesis, (2) inhibition of tumor colony growth, and (3) reversion of the transformed morphology of the tumor cells. The PDGF antibodies showed no effect on the DNA synthesis of another glioblastoma cells line (U-343MGa 31L) or on Ki-ras-transformed fibroblasts. The present study demonstrates an endogenously activated PDGF pathway in a spontaneous human glioblastoma cell line. Furthermore, we provide evidence that the autocrine PDGF pathway drives the transformed phenotype of the tumor cells, a process that can be blocked by extracellular antagonists.

  6. Effect of PTTG on endogenous gene expression in HEK 293 cells

    Directory of Open Access Journals (Sweden)

    Panguluri Siva K

    2009-12-01

    Full Text Available Abstract Background Pituitary tumor transforming gene (PTTG, also known as securin, is highly expressed in various tumors including pituitary, thyroid, colon, ovary, testis, lung, and breast. An overexpression of PTTG enhances cell proliferation, induces cellular transformation in vitro, and promotes tumor development in nude mice. PTTG also inhibits separation of sister chromatids leading to aneuploidy and genetic instability. A great amount of work has been undertaken to understand the biology of PTTG and its expression in various tumors. However, mechanisms by which PTTG mediates its tumorigenic function are not fully understood. To utilize this gene for cancer therapy, identification of the downstream signaling genes regulated by PTTG in mediation of its tumorigenic function is necessary. For this purpose, we expressed PTTG in human embryonic kidney (HEK293 cells that do not express PTTG and analyzed the downstream genes using microarray analysis. Results A total of 22,277 genes printed on an Affymetrix HG-U133A 2.0 GeneChip™ array were screened with labeled cRNA prepared from HEK293 cells infected with adenovirus vector expressing PTTG cDNA (AdPTTG cDNA and compared with labeled cRNA prepared from HEK293 cells infected with control adenovirus (control Ad or adenovirus vector expressing GFP (AdGFP. Out of 22,277 genes, 71 genes were down-regulated and 35 genes were up-regulated with an FDR corrected p-value of ≤ 0.05 and a fold change of ≥2. Most of the altered genes identified are involved in the cell cycle and cell apoptosis; a few are involved in mRNA processing and nitrogen metabolism. Most of the up-regulated genes belong to the histone protein family. Conclusion PTTG is a well-studied oncogene for its role in tumorigenesis. In addition to its importance in regulation of the cell cycle, this gene has also been recently shown to play a role in the induction of cell apoptosis. The microarray analysis in the present study

  7. RAS/ERK modulates TGFβ-regulated PTEN expression in human pancreatic adenocarcinoma cells

    OpenAIRE

    Chow, Jimmy Y.C.; Quach, Khai T.; Cabrera, Betty L.; Cabral, Jennifer A.; Beck, Stayce E.; Carethers, John M.

    2007-01-01

    Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is rarely mutated in pancreatic cancers, but its regulation by transforming growth factor (TGF)-β might mediate growth suppression and other oncogenic actions. Here, we examined the role of TGFβ and the effects of oncogenic K-RAS/ERK upon PTEN expression in the absence of SMAD4. We utilized two SMAD4-null pancreatic cell lines, CAPAN-1 (K-RAS mutant) and BxPc-3 (WT-K-RAS), both of which express TGFβ surface receptors. Cells were t...

  8. Comments on Georgeff's Transformation and Reduction Strategies for Typed Lambda Expressions

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis

    1986-01-01

    In his recent paper, Georgeff [1] considers the evaluation of lambda expres sions (with reducing reflexive types) on a variant of Landin's SECD machine. It is observed that for so-called simple expressions the SECD machine will construct stack-like environment structures, whereas, in general......, they are tree-like. Georgeff then explores the idea of transforming any (typed) lambda expression into simple form and then using the SECD machine for these expressions. However, such transformations might be undesirable if the language is going to be interpreted directly. This leads Georgeff to modify the SECD...

  9. Ultrasound Effect on Gene Expression of Sex Determining Region Y-box 9 (SOX9 and Transforming Growth Factor β Isoforms in Adipose Stem Cells

    Directory of Open Access Journals (Sweden)

    Hajar Shafaei

    2016-04-01

    Full Text Available Background Cartilage tissue engineering is a promising method for repair of cartilage defects. Induction of chondrogenesis in mesenchymal stem cells (MSC is currently used in cartilage tissue engineering. Among growth factors, transforming growth factor β (TGF-β is common chondrogenic inducer but toward hypertrophic chondrocyte. However, mechanical factors such as ultrasound could stimulate chondrogenesis. Objectives We aimed to investigate stimulation of endogenous TGF-β genes expression by low intensity pulsed ultrasound (LIPUS in MSC. Materials and Methods In this experimental study, adipose tissue stem cells (ASC cultures were treated with or without LIPUS (30 mW/cm2, 20 min/day and with or without TGF-β3 (10 ng/mL for 4 or 14 days. Chondrogenic gene expression of SOX9 and members of TGF-β family (β1, β2 and β3 was assessed in ASC cultures at day 4 and 14 by real time PCR. Results The gene expression of SOX9 significantly increased by LIPUS and TGF-β treatment versus control cultures. Exogenous TGF-β3 treatment stimulated endogenous TGF-β1 and β2 gene expressions more than LIPUS treated cultures at day 4. LIPUS, TGF-β and LIPUS plus TGF-β treated cultures expressed same TGF-β3 gene expression at day 4. The expression of TGF-β1 and β2 decreased by LIPUS in comparison to TGF-β treated cultures at day 14. Conclusions Our results suggest that LIPUS might initiate differentiation of ASC without enhancing endogenous TGF-β genes in in-vitro.

  10. Human Wharton’s jelly-derived mesenchymal stem cells express oocyte developmental genes during co-culture with placental cells

    Directory of Open Access Journals (Sweden)

    Hamid Reza Asgari

    2015-01-01

    Conclusion: Placental cell supplementsTransforming growth factor (TGF α, β and basic fibroblast growth factor (bFGF in a co-culture model can provide proper environment for induction of HUMSCs into PGCs and expression of oocyte-like markers.

  11. Cell Transformation by PTP1B Truncated Mutants Found in Human Colon and Thyroid Tumors.

    Science.gov (United States)

    Mei, Wenhan; Wang, Kemin; Huang, Jian; Zheng, Xinmin

    2016-01-01

    Expression of wild-type protein tyrosine phosphatase (PTP) 1B may act either as a tumor suppressor by dysregulation of protein tyrosine kinases or a tumor promoter through Src dephosphorylation at Y527 in human breast cancer cells. To explore whether mutated PTP1B is involved in human carcinogenesis, we have sequenced PTP1B cDNAs from human tumors and found splice mutations in ~20% of colon and thyroid tumors. The PTP1BΔE6 mutant expressed in these two tumor types and another PTP1BΔE5 mutant expressed in colon tumor were studied in more detail. Although PTP1BΔE6 revealed no phosphatase activity compared with wild-type PTP1B and the PTP1BΔE5 mutant, its expression induced oncogenic transformation of rat fibroblasts without Src activation, indicating that it involved signaling pathways independent of Src. The transformed cells were tumourigenic in nude mice, suggesting that the PTP1BΔE6 affected other molecule(s) in the human tumors. These observations may provide a novel therapeutic target for colon and thyroid cancer.

  12. Chronic exposure to arsenic, estrogen, and their combination causes increased growth and transformation in human prostate epithelial cells potentially by hypermethylation-mediated silencing of MLH1.

    Science.gov (United States)

    Treas, Justin; Tyagi, Tulika; Singh, Kamaleshwar P

    2013-11-01

    Chronic exposure to arsenic and estrogen is associated with risk of prostate cancer, but their mechanism is not fully understood. Additionally, the carcinogenic effects of their co-exposure are not known. Therefore, the objective of this study was to evaluate the effects of chronic exposure to arsenic, estrogen, and their combination, on cell growth and transformation, and identify the mechanism behind these effects. RWPE-1 human prostate epithelial cells were chronically exposed to arsenic and estrogen alone and in combination. Cell growth was measured by cell count and cell cycle, whereas cell transformation was evaluated by colony formation assay. Gene expression was measured by quantitative real-time PCR and confirmed at protein level by Western blot analysis. MLH1 promoter methylation was determined by pyrosequencing method. Exposure to arsenic, estrogen, and their combinations increases cell growth and transformation in RWPE-1 cells. Increased expression of Cyclin D1 and Bcl2, whereas decreased expression of mismatch repair genes MSH4, MSH6, and MLH1 was also observed. Hypermethylation of MLH1 promoter further suggested the epigenetic inactivation of MLH1 expression in arsenic and estrogen treated cells. Arsenic and estrogen combination caused greater changes than their individual treatments. Findings of this study for the first time suggest that arsenic and estrogen exposures cause increased cell growth and survival potentially through epigenetic inactivation of MLH1 resulting in decreased MLH1-mediated apoptotic response, and consequently increased cellular transformation. © 2013 Wiley Periodicals, Inc.

  13. 2D-DIGE and MALDI TOF/TOF MS analysis reveal that small GTPase signaling pathways may play an important role in cadmium-induced colon cell malignant transformation

    International Nuclear Information System (INIS)

    Lu, Jian; Zhou, Zhongping; Zheng, Jianzhou; Zhang, Zhuyi; Lu, Rongzhu; Liu, Hanqing; Shi, Haifeng; Tu, Zhigang

    2015-01-01

    Cadmium is a toxic heavy metal present in the environment and in industrial materials. Cadmium has demonstrated carcinogenic activity that induces cell transformation, but how this occurs is unclear. We used 2D-DIGE and MALDI TOF/TOF MS combined with bioinformatics and immunoblotting to investigate the molecular mechanism of cadmium transformation. We found that small GTPases were critical for transformation. Additionally, proteins involved in mitochondrial transcription, DNA repair, and translation also had altered expression patterns in cadmium treated cells. Collectively, our results suggest that activation of small GTPases contributes to cadmium-induced transformation of colon cells. - Highlights: • Colon epithelial cell line is firstly successfully transformed by cadmium. • 2D-DIGE is applied to visualize the differentially expressed proteins. • RhoA plays an important role in cadmium induced malignant transformation. • Bioinformatic and experimental methods are combined to explore new mechanisms.

  14. 2D-DIGE and MALDI TOF/TOF MS analysis reveal that small GTPase signaling pathways may play an important role in cadmium-induced colon cell malignant transformation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jian, E-mail: lujian@ujs.edu.cn [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Zhou, Zhongping [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Zheng, Jianzhou [Department of Respiration Medicine, Changzhou No.2 People' s Hospital, Changzhou 213003 (China); Zhang, Zhuyi [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Lu, Rongzhu [School of Medicine, Jiangsu University, Zhenjiang 212013 (China); Liu, Hanqing [School of Pharmacy, Jiangsu University, Zhenjiang 212013 (China); Shi, Haifeng [Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China); Tu, Zhigang, E-mail: tuzg_ujs@ujs.edu.cn [Institute of Life Sciences, Jiangsu University, Zhenjiang 212013 (China)

    2015-10-01

    Cadmium is a toxic heavy metal present in the environment and in industrial materials. Cadmium has demonstrated carcinogenic activity that induces cell transformation, but how this occurs is unclear. We used 2D-DIGE and MALDI TOF/TOF MS combined with bioinformatics and immunoblotting to investigate the molecular mechanism of cadmium transformation. We found that small GTPases were critical for transformation. Additionally, proteins involved in mitochondrial transcription, DNA repair, and translation also had altered expression patterns in cadmium treated cells. Collectively, our results suggest that activation of small GTPases contributes to cadmium-induced transformation of colon cells. - Highlights: • Colon epithelial cell line is firstly successfully transformed by cadmium. • 2D-DIGE is applied to visualize the differentially expressed proteins. • RhoA plays an important role in cadmium induced malignant transformation. • Bioinformatic and experimental methods are combined to explore new mechanisms.

  15. N-methyl-N-nitro-N-nitrosoguanidine-mediated ING4 downregulation contributed to the angiogenesis of transformed human gastric epithelial cells.

    Science.gov (United States)

    Chen, Yansu; Fu, Rui; Xu, Mengdie; Huang, Yefei; Sun, Guixiang; Xu, Lichun

    2018-04-15

    Angiogenesis is associated with the progression and mortality of gastric cancer. Epidemiological evidences indicate that long-term N-nitroso compounds (NOCs) exposure predominantly contributes to the mortality of gastric cancer. Therefore, further reduced mortality of gastric cancer demands to explore the exact mechanisms of NOCs induced angiogenesis. As a tumor suppressor gene, inhibitor of growth protein 4 (ING4) plays an important role in pathological angiogenesis. In this study, we will investigate ING4 expression level in human gastric epithelial cells after the long-term low dose exposure of N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and the pathological impact of MNNG-reduced ING4 on angiogenesis of transformed cells. The soft agar colony formation assay, Western blotting, immunofluorescence and wound healing assay were used to evaluate the characteristics of transformed cells. HUVEC growth and tube formation assays were performed to test the angiogenic abilities. EMSA, luciferase reporter gene assay, real-time PCR and Western blotting were used to explore the exact mechanism. By establishing transformed human gastric epithelial cells via chronic low dose treatment, a gradually ING4 downregulation was observed in the later-stage of MNNG-induced cell transformation. Moreover, we demonstrated that MNNG exposure-reduced ING4 expression significantly resulted into aggravating angiogenesis through increasing the phosphorylation level of NF-κB p65 and subsequently DAN binding activity and regulating the expressions of NF-κB p65 downstream pro-angiogenic genes, MMP-2 and MMP-9. Our findings provided a significant mechanistic insight into angiogenesis of MNNG-transformed human gastric epithelial cell and supported the concept that ING4 may be a relevant therapeutic target for gastric cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Different roles of ROS and Nrf2 in Cr(VI)-induced inflammatory responses in normal and Cr(VI)-transformed cells

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Ram Vinod; Pratheeshkumar, Poyil; Son, Yong-Ok; Wang, Lei [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Hitron, John Andrew [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Divya, Sasidharan Padmaja; Zhang, Zhuo [Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States); Shi, Xianglin, E-mail: xshi5@email.uky.edu [Center for Research on Environmental Disease, University of Kentucky, 1095 VA Drive, Lexington, KY 40536 (United States)

    2016-09-15

    Hexavalent chromium (Cr(VI)) is classified as a human carcinogen. Cr(VI) has been associated with adenocarcinomas and squamous cell carcinoma of the lung. The present study shows that acute Cr(VI) treatment in human bronchial epithelial cells (BEAS-2B) increased inflammatory responses (TNF-α, COX-2, and NF-кB/p65) and expression of Nrf2. Cr(VI)-induced generation of reactive oxygen species (ROS) are responsible for increased inflammation. Despite the fact that Nrf2 is a master regulator of response to oxidative stress, silencing of Nrf2 in the acute Cr(VI) treatment had no effect on Cr(VI)-induced inflammation. In contrast, in Cr(VI)-transformed (CrT) cells, Nrf2 is constitutively activated. Knock-down of this protein resulted in decreased inflammation, while silencing of SOD2 and CAT had no effect in the expression of these inflammatory proteins. Results obtained from the knock-down of Nrf2 in CrT cells are very different from the results obtained in the acute Cr(VI) treatment. In BEAS-2B cells, knock-down of Nrf2 had no effect in the inflammation levels, while in CrT cells a decrease in the expression of inflammation markers was observed. These results indicate that before transformation, ROS plays a critical role while Nrf2 not in Cr(VI)-induced inflammation, whereas after transformation (CrT cells), Nrf2 is constitutively activated and this protein maintains inflammation while ROS not. Constitutively high levels of Nrf2 in CrT binds to the promoter regions of COX-2 and TNF-α, leading to increased inflammation. Collectively, our results demonstrate that before cell transformation ROS are important in Cr(VI)-induced inflammation and after transformation a constitutively high level of Nrf2 is important. - Highlights: • Cr(VI)-induced ROS increased inflammation, while Nrf2 had no effect. • In the CrT cells knock-down of Nrf2 resulted in decreased inflammation. • Mechanistic differences in regulating Cr(VI)-induced inflammation.

  17. MSH3-deficiency initiates EMAST without oncogenic transformation of human colon epithelial cells.

    Directory of Open Access Journals (Sweden)

    Christoph Campregher

    Full Text Available BACKGROUND/AIM: Elevated microsatellite instability at selected tetranucleotide repeats (EMAST is a genetic signature in certain cases of sporadic colorectal cancer and has been linked to MSH3-deficiency. It is currently controversial whether EMAST is associated with oncogenic properties in humans, specifically as cancer development in Msh3-deficient mice is not enhanced. However, a mutator phenotype is different between species as the genetic positions of repetitive sequences are not conserved. Here we studied the molecular effects of human MSH3-deficiency. METHODS: HCT116 and HCT116+chr3 (both MSH3-deficient and primary human colon epithelial cells (HCEC, MSH3-wildtype were stably transfected with an EGFP-based reporter plasmid for the detection of frameshift mutations within an [AAAG]17 repeat. MSH3 was silenced by shRNA and changes in protein expression were analyzed by shotgun proteomics. Colony forming assay was used to determine oncogenic transformation and double strand breaks (DSBs were assessed by Comet assay. RESULTS: Despite differential MLH1 expression, both HCT116 and HCT116+chr3 cells displayed comparable high mutation rates (about 4×10(-4 at [AAAG]17 repeats. Silencing of MSH3 in HCECs leads to a remarkable increased frameshift mutations in [AAAG]17 repeats whereas [CA]13 repeats were less affected. Upon MSH3-silencing, significant changes in the expression of 202 proteins were detected. Pathway analysis revealed overexpression of proteins involved in double strand break repair (MRE11 and RAD50, apoptosis, L1 recycling, and repression of proteins involved in metabolism, tRNA aminoacylation, and gene expression. MSH3-silencing did not induce oncogenic transformation and DSBs increased 2-fold. CONCLUSIONS: MSH3-deficiency in human colon epithelial cells results in EMAST, formation of DSBs and significant changes of the proteome but lacks oncogenic transformation. Thus, MSH3-deficiency alone is unlikely to drive human colon

  18. Germ Cell Proteins in Melanoma: Prognosis, Diagnosis, Treatment, and Theories on Expression

    International Nuclear Information System (INIS)

    Rosa, A. M.; Dabas, N.; Byrnes, D. M.; Eller, M. S.; Grichnik, J. M.; Grichnik, J M.; Grichnik, J M.

    2012-01-01

    Germ cell protein expression in melanoma has been shown to correlate with malignancy, severity of disease and to serve as an immunologic target for therapy. However, very little is known about the role that germ cell proteins play in cancer development. Unique germ cell pathways include those involved in immortalization, genetic evolution, and energy metabolism. There is an ever increasing recognition that within tumors there is a subpopulation of cells with stem-cell-like characteristics that play a role in driving tumor genesis. Stem cell and germ cell biology is intertwined. Given the enormous potential and known expression of germ cell proteins in melanoma, it is possible that they represent a largely untapped resource that may play a fundamental role in tumor development and progression. The purpose of this paper is to provide an update on the current value of germ cell protein expression in melanoma diagnosis, prognosis, and therapy, as well as to review critical germ cell pathways and discuss the potential roles these pathways may play in malignant transformation

  19. Cell-mediated mutagenesis and cell transformation of mammalian cells by chemical carcinogens

    International Nuclear Information System (INIS)

    Huberman, E.; Langenbach, R.

    1977-01-01

    We have developed a cell-mediated mutagenesis assay in which cells with the appropriate markers for mutagenesis are co-cultivated with either lethally irradiated rodent embryonic cells that can metabolize carcinogenic hydrocarbons or with primary rat liver cells that can metabolize chemicals carcinogenic to the liver. During co-cultivation, the reactive metabolites of the procarcinogen appear to be transmitted to the mutable cells and induce mutations in them. Assays of this type make it possible to demonstrate a relationship between carcinogenic potency of the chemicals and their ability to induce mutations in mammalian cells. In addition, by simultaneously comparing the frequencies of transformation and mutation induced in normal diploid hamster cells by benzo(a)pyrene (BP) and one of its metabolites, it is possible to estimate the genetic target size for cell transformation in vitro

  20. Sequence of activation of template biosyntheses in normal and transformed human cells after synchronization with a double thimidine block

    International Nuclear Information System (INIS)

    Alekseev, S.B.; Boikov, P.Ya.; Ebralidze, L.K.; Stepanova, L.G.

    1986-01-01

    The sequences of synthesis of DNA, RNA, and various groups of proteins in normal and transformed human fibroblasts was studied in the first mitotic cycle synchronization of the cells by a double thymidine block. Two peculiarities of the synthesis of acid-soluble histone and acid-insoluble proteins in the normal and transformed cells, were detected: (1) in normal fibroblasts the synthesis of the two groups of proteins is a minimum before DNA replication, and the greatest activity is achieved in the G 2 phase; in transformed cells protein synthesis is a maximum after the removal of the thymine block, while in the G 2 phase it is decreased; (2) in normal fibroblasts the synthesis of acid-insoluble proteins is a maximum before the maximum synthesis of DNA, and that of acid-soluble proteins is a maximum after the maximum of DNA synthesis. The opposite picture is observed in transformed cells. RNA synthesis in normal and transformed cells is activated at the end of the G 2 phase. In normal cells the synthesis of proteins is coupled with the activation of RNA synthesis, while in transformed cells protein synthesis is evidently transferred to the following mitotic cycle. Especially pronounced differences were detected in the expression of certain LMG proteins. Thus, in transformed cells the regulation of the coupling of the template syntheses is modified

  1. WRN-targeted therapy using inhibitors NSC 19630 and NSC 617145 induce apoptosis in HTLV-1-transformed adult T-cell leukemia cells

    Directory of Open Access Journals (Sweden)

    R. Moles

    2016-11-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 infection is associated with adult T-cell leukemia/lymphoma (ATLL, a lymphoproliferative malignancy with a dismal prognosis and limited therapeutic options. Recent evidence shows that HTLV-1-transformed cells present defects in both DNA replication and DNA repair, suggesting that these cells might be particularly sensitive to treatment with a small helicase inhibitor. Because the “Werner syndrome ATP-dependent helicase” encoded by the WRN gene plays important roles in both cellular proliferation and DNA repair, we hypothesized that inhibition of WRN activity could be used as a new strategy to target ATLL cells. Methods Our analysis demonstrates an apoptotic effect induced by the WRN helicase inhibitor in HTLV-1-transformed cells in vitro and ATL-derived cell lines. Inhibition of cellular proliferation and induction of apoptosis were demonstrated with cell cycle analysis, XTT proliferation assay, clonogenic assay, annexin V staining, and measurement of mitochondrial transmembrane potential. Results Targeted inhibition of the WRN helicase induced cell cycle arrest and apoptosis in HTLV-1-transformed leukemia cells. Treatment with NSC 19630 (WRN inhibitor induces S-phase cell cycle arrest, disruption of the mitochondrial membrane potential, and decreased expression of anti-apoptotic factor Bcl-2. These events were associated with activation of caspase-3-dependent apoptosis in ATL cells. We identified some ATL cells, ATL-55T and LMY1, less sensitive to NSC 19630 but sensitive to another WRN inhibitor, NSC 617145. Conclusions WRN is essential for survival of ATL cells. Our studies suggest that targeting the WRN helicase with small inhibitors is a novel promising strategy to target HTLV-1-transformed ATL cells.

  2. Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Nakamura, Ryosuke; Kayamori, Kou; Oue, Erika; Sakamoto, Kei; Harada, Kiyoshi; Yamaguchi, Akira

    2015-01-01

    Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC

  3. Transforming growth factor-β synthesized by stromal cells and cancer cells participates in bone resorption induced by oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Ryosuke [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Kayamori, Kou [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Oue, Erika [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Sakamoto, Kei [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Harada, Kiyoshi [Department of Maxillofacial Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Yamaguchi, Akira, E-mail: akira.mpa@tmd.ac.jp [Department of Oral Pathology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan)

    2015-03-20

    Transforming growth factor beta (TGF-β) plays a significant role in the regulation of the tumor microenvironment. To explore the role of TGF-β in oral cancer-induced bone destruction, we investigated the immunohistochemical localization of TGF-β and phosphorylated Smad2 (p-Smad2) in 12 surgical specimens of oral squamous cell carcinoma (OSCC). These studies revealed TGF-β and p-Smad2 expression in cancer cells in all tested cases. Several fibroblasts located between cancer nests and resorbing bone expressed TGF-β in 10 out of 12 cases and p-Smad2 in 11 out of 12 cases. Some osteoclasts also exhibited p ∼ Smad2 expression. The OSCC cell line, HSC3, and the bone marrow-derived fibroblastic cell line, ST2, synthesized substantial levels of TGF-β. Culture media derived from HSC3 cells could stimulate Tgf-β1 mRNA expression in ST2 cells. Recombinant TGF-β1 could stimulate osteoclast formation induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in RAW264 cells. TGF-β1 could upregulate the expression of p-Smad2 in RAW264 cells, and this action was suppressed by the addition of a neutralizing antibody against TGF-β or by SB431542. Transplantation of HSC3 cells onto the calvarial region of athymic mice caused bone destruction, associated with the expression of TGF-β and p-Smad2 in both cancer cells and stromal cells. The bone destruction was substantially inhibited by the administration of SB431542. The present study demonstrated that TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC-induced bone destruction. - Highlights: • Cancer cell, fibroblastic cells, and osteoclasts at bone resorbing area by oral cancer exhibited TGF-β and p-Smad2. • TGF-β1 stimulated osteoclastogenesis induced by RAKL in RAW264 cell. • Xenograft model of oral cancer-induced bone resorption was substantially inhibited by SB431542. • TGF-β synthesized by both cancer cells and stromal cells participates in the OSCC

  4. Embryonic expression of the transforming growth factor beta ligand and receptor genes in chicken.

    Science.gov (United States)

    Cooley, James R; Yatskievych, Tatiana A; Antin, Parker B

    2014-03-01

    Transforming growth factor-beta (TGFβ) signaling regulates a myriad of biological processes during embryogenesis, in the adult, and during the manifestation of disease. TGFβ signaling is propagated through one of three TGFβ ligands interacting with Type I and Type II receptors, and Type III co-receptors. Although TGFβ signaling is regulated partly by the combinatorial expression patterns of TGFβ receptors and ligands, a comprehensive gene expression analysis has not been published. Here we report the embryonic mRNA expression patterns in chicken embryos of the canonical TGFβ ligands (TGFB1, TGFB2, and TGFB3) and receptors (TGFBR1, TGFBR2, TGFBR3), plus the Activin A receptor, type 1 (ACVR1) and co receptor Endoglin (ENG) that also transduce TGFβ signaling. TGFB ligands and receptors show dynamic and frequently overlapping expression patterns in numerous embryonic cell layers and structures. Integrating expression information identifies combinations of ligands and receptors that are involved in specific developmental processes including somitogenesis, cardiogenesis and vasculogenesis. Copyright © 2013 Wiley Periodicals, Inc.

  5. Increased ICAM-1 Expression in Transformed Human Oral Epithelial Cells: Molecular Mechanism and Functional Role in Peripheral Blood Mononuclear Cell Adhesion and Lymphokine-Activated-Killer Cell Cytotoxicity

    Science.gov (United States)

    Huang, George T.-J.; Zhang, Xinli; Park, No-Hee

    2012-01-01

    The intercellular adhesion molecule-1 (ICAM-1, CD54) serves as a counter-receptor for the β2-integrins, LFA-1 and Mac-1, which are expressed on leukocytes. Although expression of ICAM-1 on tumor cells has a role in tumor progression and development, information on ICAM-1 expression and its role in oral cancer has not been established. Normal human oral keratinocytes (NHOK), human papilloma virus (HPV)-immortalized human oral keratinocyte lines (HOK-16B, HOK-18A, and HOK-18C), and six human oral neoplastic cell lines (HOK-16B-BaP-T1, SCC-4, SCC-9, HEp-2, Tu-177 and 1483) were used to study ICAM-1 expression and its functional role in vitro. Our results demonstrated that NHOK express negligible levels of ICAM-1, whereas immortalized human oral keratinocytes and cancer cells express significantly higher levels of ICAM-1, except for HOK-16B-BaP-T1 and HEp-2. Altered mRNA half-lives did not fully account for the increased accumulation of ICAM-1 mRNA. Adhesion of peripheral blood mononuclear cells (PBMC) to epithelial cells correlated with cell surface ICAM-1 expression levels. This adhesion was inhibited by antibodies specific for either ICAM-1 or LFA-1/Mac-1, suggesting a role for these molecules in adhesion. In contrast, lymphokine-activated-killer (LAK) cell cytotoxic killing of epithelial cells did not correlate with ICAM-1 levels or with adhesion. Nonetheless, within each cell line, blocking of ICAM-1 or LFA-1/Mac-1 reduced LAK cells killing, suggesting that ICAM-1 is involved in mediating this killing. PMID:10938387

  6. Expression of transforming growth factor alpha and epidermal growth factor receptor in rat lung neoplasms induced by plutonium-239

    International Nuclear Information System (INIS)

    Stegelmeier, B.L.; Gillett, N.A.; Hahn, F.F.; Kelly, G.; Rebar, A.H.

    1994-01-01

    Ninety-two rat lung proliferative lesions and neoplasms induced by inhaled 239 PuO 2 were evaluated for aberrant expression of transforming growth factor alpha (TGF-α) and epidermal growth factor receptor (EGFR). Expression of TGF-α protein, measured by immunohistochemistry, was higher in 94% of the squamous cell carcinomas and 87% of the foci of alveolar epithelial squamous metaplasia than that exhibited by the normal-appearing, adjacent lung parenchyma. In contrast, only 20% of adenocarcinomas and foci of epithelial hyperplasia expressed elevated levels of TGF-α. Many neoplasms expressing TGF-α also expressed excessive levels of EGFR mRNA. Southern and DNA slot blot analyses showed that the elevated EGFR expression was not due to amplification of the EGFR gene. These data suggest that increased amounts of TGF-α were early alterations in the progression of plutonium-induced squamous cell carcinoma, and these increases may occur in parallel with overexpression of the receptor for this growth factor. Together, these alterations create a potential autocrine loop for sustaining clonal expansion of cells initiated by high-LET radiation. 44 refs., 4 figs., 1 tab

  7. Dissecting the hydrogenase expression and activity of transformed escherichia coli with the bidirectional NiFe-hydrogenase from synechocystis sp. PCC 6803

    International Nuclear Information System (INIS)

    Moon, Yu Ran; Lee, Min Hee; An, Byung Chull; Chung, Byung Yeoup; Kim, Jae Sung; Kim, Jin Hong; Park, Youn Il; Kim, Cha Soon

    2009-01-01

    Synechocystis bidirectional hydrogenase genes (hoxEFUYH) and their putative promoter regions and transformed into E. coli. The hox genes were transcribed in the E. coli cells carrying the vector construct of pCCIFOS::phox::hox or pCCIFOS::pT7::hox and translated into HoxEFUYH proteins, suggesting that the putative hox promoter can be constitutively activated in E. coli. Accordingly, the total hydrogenase activity was markedly increased up to 192% or 169% in the transformed cells, while the hydrogen uptake was decreased up to about 30% of the negative control. Although the gene expression of LexA, the only one transcription regulator proven for the hox genes, was substantially decreased in the pCCIFOS::phox::hox cells after γ-irradiation of 30 Gy, the expression levels of HoxEFUYH proteins were not altered significantly. Thus, it is also suggested that other transcription regulators as well as LexA might contribute to activation of the hox promoter in E. coli

  8. Global gene expression changes in human urothelial cells exposed to low-level monomethylarsonous acid

    International Nuclear Information System (INIS)

    Medeiros, Matthew; Zheng, Xinghui; Novak, Petr; Wnek, Shawn M.; Chyan, Vivian; Escudero-Lourdes, Claudia; Gandolfi, A. Jay

    2012-01-01

    Highlights: ► Chronic exposure to 50 nM monomethylarsonous acid in UROtsa was investigated. ► At 3 months of exposure substantial changes were observed in gene expression. ► Notable changes occurred in mitogenic signaling, stress, immune and inflammatory responses. ► Gene expression changes correlate with phenotypic changes from previous studies. -- Abstract: Bladder cancer has been associated with chronic arsenic exposure. Monomethylarsonous acid [MMA(III)] is a metabolite of inorganic arsenic and has been shown to transform an immortalized urothelial cell line (UROtsa) at concentrations 20-fold less than arsenite. MMA(III) was used as a model arsenical to examine the mechanisms of arsenical-induced transformation of urothelium. A microarray analysis was performed to assess the transcriptional changes in UROtsa during the critical window of chronic 50 nM MMA(III) exposure that leads to transformation at 3 months of exposure. The analysis revealed only minor changes in gene expression at 1 and 2 months of exposure, contrasting with substantial changes observed at 3 months of exposure. The gene expression changes at 3 months were analyzed showing distinct alterations in biological processes and pathways such as a response to oxidative stress, enhanced cell proliferation, anti-apoptosis, MAPK signaling, as well as inflammation. Twelve genes selected as markers of these particular biological processes were used to validate the microarray and these genes showed a time-dependent changes at 1 and 2 months of exposure, with the most substantial changes occurring at 3 months of exposure. These results indicate that there is a strong association between the acquired phenotypic changes that occur with chronic MMA(III) exposure and the observed gene expression patterns that are indicative of a malignant transformation. Although the substantial changes that occur at 3 months of exposure may be a consequence of transformation, there are common occurrences of altered

  9. Microtubule reorganization in tobacco BY-2 cells stably expressing GFP-MBD

    Science.gov (United States)

    Granger, C. L.; Cyr, R. J.

    2000-01-01

    Microtubule organization plays an important role in plant morphogenesis; however, little is known about how microtubule arrays transit from one organized state to another. The use of a genetically incorporated fluorescent marker would allow long-term observation of microtubule behavior in living cells. Here, we have characterized a Nicotiana tabacum L. cv. Bright Yellow 2 (BY-2) cell line that had been stably transformed with a gfp-mbd construct previously demonstrated to label microtubules (J. Marc et al., 1998, Plant Cell 10: 1927-1939). Fluorescence levels were low, but interphase and mitotic microtubule arrays, as well as the transitions between these arrays, could be observed in individual gfp-mbd-transformed cells. By comparing several attributes of transformed and untransformed cells it was concluded that the transgenic cells are not adversely affected by low-level expression of the transgene and that these cells will serve as a useful and accurate model system for observing microtubule reorganization in vivo. Indeed, some initial observations were made that are consistent with the involvement of motor proteins in the transition between the spindle and phragmoplast arrays. Our observations also support the role of the perinuclear region in nucleating microtubules at the end of cell division with a progressive shift of these microtubules and/or nucleating activity to the cortex to form the interphase cortical array.

  10. Involvement of p53 Mutation and Mismatch Repair Proteins Dysregulation in NNK-Induced Malignant Transformation of Human Bronchial Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Ying Shen

    2014-01-01

    Full Text Available Genome integrity is essential for normal cellular functions and cell survival. Its instability can cause genetic aberrations and is considered as a hallmark of most cancers. To investigate the carcinogenesis process induced by tobacco-specific carcinogen NNK, we studied the dynamic changes of two important protectors of genome integrity, p53 and MMR system, in malignant transformation of human bronchial epithelial cells after NNK exposure. Our results showed that the expression of MLH1, one of the important MMR proteins, was decreased early and maintained the downregulation during the transformation in a histone modification involved and DNA methylation-independent manner. Another MMR protein PMS2 also displayed a declined expression while being in a later stage of transformation. Moreover, we conducted p53 mutation analysis and revealed a mutation at codon 273 which led to the replacement of arginine by histidine. With the mutation, DNA damage-induced activation of p53 was significantly impaired. We further reintroduced the wild-type p53 into the transformed cells, and the malignant proliferation can be abrogated by inducing cell cycle arrest and apoptosis. These findings indicate that p53 and MMR system play an important role in the initiation and progression of NNK-induced transformation, and p53 could be a potential therapeutic target for tobacco-related cancers.

  11. Keratin 5/14‑mediated cell differentiation and transformation are regulated by TAp63 and Notch‑1 in oral squamous cell carcinoma‑derived cells.

    Science.gov (United States)

    Srivastava, Saumya S; Alam, Hunain; Patil, Sonam J; Shrinivasan, Rashmi; Raikundalia, Sweta; Chaudhari, Pratik Rajeev; Vaidya, Milind M

    2018-05-01

    Keratins 5/14 (K5/14) are intermediate filament proteins expressed in the basal layer of stratified epithelial cells and are known targets of p63. Previous research in our laboratory showed that upon K5/14 downregulation in oral squamous cell carcinoma (OSCC)‑derived cells, there was an increase in intracellular Notch‑1 levels and differentiation markers such as involucrin, keratin 1 and a decrease in tumorigenic potential in vivo. However, the molecules involved in the K14 regulated cell differentiation and transformation are not known to date. In order to understand the possible role of TAp63, we downregulated TAp63 in a K14‑knockdown background. We observed that there was a decrease in the expression of Notch‑1. Expression levels of differentiation markers such as involucrin, K1, loricrin and filaggrin were also decreased. Furthermore, TAp63 downregulation led to an increase in invasion, migration and in vivo tumorigenic potential of these cells. We observed a decrease in β‑catenin signaling in K14‑downregulated cells. Notably, when TAp63 was downregulated in K14‑knockdown cells, there was increase in non‑phospho β‑catenin levels. Hence, this study indicates that TAp63 plays an important role in K14‑downregulated cells possibly by regulating the Notch‑1 expression. K14 regulates the expression of TAp63 which in turn regulates expression of Notch‑1. The present study is a step forward in our quest to understand the functional significance of molecules that regulate the process of differentiation and tumorigenesis in stratified epithelial cells.

  12. Application of the inter-line PCR for the analyse of genomic rearrangements in radiation-transformed mammalian cell lines

    International Nuclear Information System (INIS)

    Leibhard, S.; Smida, J.

    1996-01-01

    Repetitive DNA sequences of the LINE-family (long interspersed elements) that are widely distributed among the mammalian genome can be activated or altered by the exposure to ionizing radiation [1]. By the integration at new sites in the genome alterations in the expression of genes that are involved in cell transformation and/or carcinogenesis may occur [2, 3]. A new technique -the inter-LINE PCR - has been developed in order to detect and analyse such genomic rearrangements in radiation-transformed cell lines. From the sites of transformation- or tumour-specific changes in the genome it might be possible to develop new tumour markers for diagnostic purpose. (orig.) [de

  13. Myb proteins: angels and demons in normal and transformed cells.

    Science.gov (United States)

    Zhou, Ye; Ness, Scott A

    2011-01-01

    A key regulator of proliferation, differentiation and cell fate, the c-Myb transcription factor regulates the expression of hundreds of genes and is in turn regulated by numerous pathways and protein interactions. However, the most unique feature of c-Myb is that it can be converted into an oncogenic transforming protein through a few mutations that completely change its activity and specificity. The c-Myb protein is a myriad of interactions and activities rolled up in a protein that controls proliferation and differentiation in many different cell types. Here we discuss the background and recent progress that have led to a better understanding of this complex protein, and outline the questions that have yet to be answered.

  14. Depletion of 4-hydroxynonenal in hGSTA4-transfected HLE B-3 cells results in profound changes in gene expression

    International Nuclear Information System (INIS)

    Patrick, Brad; Li Jie; Jeyabal, Prince V.S.; Reddy, Prasada M.R.V.; Yang Yusong; Sharma, Rajendra; Sinha, Mala; Luxon, Bruce; Zimniak, Piotr; Awasthi, Sanjay; Awasthi, Yogesh C.

    2005-01-01

    Previously, we have shown that overexpression of 4-hydroxy-2-nonenal (HNE)-detoxifying enzyme glutathione S-transferase A4-4 (hGSTA4-4) in human lens epithelial cells (HLE B-3) leads to pro-carcinogenic phenotypic transformation of these cells [R. Sharma, et al. Eur. J. Biochem. 271 (2004) 1960-1701]. We now demonstrate that hGSTA4-transfection also causes a profound change in the expression of genes involved in cell adhesion, cell cycle control, proliferation, cell growth, and apoptosis, which is consistent with phenotypic changes of the transformed cells. The expression of p53, p21, p16, fibronectin 1, laminin γ1, connexin 43, Fas, integrin α6, TGFα, and c-jun was down-regulated, while the expression of protein kinase C beta II (PKCβII), c-myc, cyclin-dependent kinase 2 (CDK2), and TGFβ was up-regulated in transfected cells. These results demonstrate that HNE serves as a crucial signaling molecule and, by modulating the expression of genes, can influence cellular functions

  15. Malignant transformation potentials of human umbilical cord mesenchymal stem cells both spontaneously and via 3-methycholanthrene induction.

    Directory of Open Access Journals (Sweden)

    Qiuling Tang

    Full Text Available Human umbilical cord mesenchymal stem cells (HUMSCs are highly proliferative and can be induced to differentiate into advanced derivatives of all three germ layers. Thus, HUMSCs are considered to be a promising source for cell-targeted therapies and tissue engineering. However there are reports on spontaneous transformation of mesenchymal stem cells (MSCs derived from human bone marrows. The capacity for HUMSCs to undergo malignant transform spontaneously or via induction by chemical carcinogens is presently unknown. Therefore, we isolated HUMSCs from 10 donors and assessed their transformation potential either spontaneously or by treating them with 3-methycholanthrene (3-MCA, a DNA-damaging carcinogen. The malignant transformation of HUMSCs in vitro was evaluated by morphological changes, proliferation rates, ability to enter cell senescence, the telomerase activity, chromosomal abnormality, and the ability to form tumors in vivo. Our studies showed that HUMSCs from all 10 donors ultimately entered senescence and did not undergo spontaneous malignant transformation. However, HUMSCs from two of the 10 donors treated with 3-MCA displayed an increased proliferation rate, failed to enter senescence, and exhibited an altered cell morphology. When these cells (tHUMSCs were injected into immunodeficient mice, they gave rise to sarcoma-like or poorly differentiated tumors. Moreover, in contrast to HUMSCs, tHUMSCs showed a positive expression of human telomerase reverse transcriptase (hTERT and did not exhibit a shortening of the relative telomere length during the long-term culture in vitro. Our studies demonstrate that HUMSCs are not susceptible to spontaneous malignant transformation. However, the malignant transformation could be induced by chemical carcinogen 3-MCA.

  16. Malignant Transformation Potentials of Human Umbilical Cord Mesenchymal Stem Cells Both Spontaneously and via 3-Methycholanthrene Induction

    Science.gov (United States)

    Lai, Xiulan; Liu, Sizheng; Chen, Yezeng; Zheng, Zexin; Xie, Qingdong; Maldonado, Martin; Cai, Zhiwei; Qin, Shan; Ho, Guyu; Ma, Lian

    2013-01-01

    Human umbilical cord mesenchymal stem cells (HUMSCs) are highly proliferative and can be induced to differentiate into advanced derivatives of all three germ layers. Thus, HUMSCs are considered to be a promising source for cell-targeted therapies and tissue engineering. However there are reports on spontaneous transformation of mesenchymal stem cells (MSCs) derived from human bone marrows. The capacity for HUMSCs to undergo malignant transform spontaneously or via induction by chemical carcinogens is presently unknown. Therefore, we isolated HUMSCs from 10 donors and assessed their transformation potential either spontaneously or by treating them with 3-methycholanthrene (3-MCA), a DNA-damaging carcinogen. The malignant transformation of HUMSCs in vitro was evaluated by morphological changes, proliferation rates, ability to enter cell senescence, the telomerase activity, chromosomal abnormality, and the ability to form tumors in vivo. Our studies showed that HUMSCs from all 10 donors ultimately entered senescence and did not undergo spontaneous malignant transformation. However, HUMSCs from two of the 10 donors treated with 3-MCA displayed an increased proliferation rate, failed to enter senescence, and exhibited an altered cell morphology. When these cells (tHUMSCs) were injected into immunodeficient mice, they gave rise to sarcoma-like or poorly differentiated tumors. Moreover, in contrast to HUMSCs, tHUMSCs showed a positive expression of human telomerase reverse transcriptase (hTERT) and did not exhibit a shortening of the relative telomere length during the long-term culture in vitro. Our studies demonstrate that HUMSCs are not susceptible to spontaneous malignant transformation. However, the malignant transformation could be induced by chemical carcinogen 3-MCA. PMID:24339974

  17. Is expressive timing relational invariant under tempo transformation?

    NARCIS (Netherlands)

    Honing, H.

    2007-01-01

    This empirical study is concerned with examining the relation between tempo and expressive timing in music performance. This was investigated by asking listeners (N = 307) to distinguish between an original recording and a tempo-transformed version in a musical genre of their preference (jazz or

  18. Single-Cell Mass Spectrometry Reveals Changes in Lipid and Metabolite Expression in RAW 264.7 Cells upon Lipopolysaccharide Stimulation

    Science.gov (United States)

    Yang, Bo; Patterson, Nathan Heath; Tsui, Tina; Caprioli, Richard M.; Norris, Jeremy L.

    2018-05-01

    It has been widely recognized that individual cells that exist within a large population of cells, even if they are genetically identical, can have divergent molecular makeups resulting from a variety of factors, including local environmental factors and stochastic processes within each cell. Presently, numerous approaches have been described that permit the resolution of these single-cell expression differences for RNA and protein; however, relatively few techniques exist for the study of lipids and metabolites in this manner. This study presents a methodology for the analysis of metabolite and lipid expression at the level of a single cell through the use of imaging mass spectrometry on a high-performance Fourier transform ion cyclotron resonance mass spectrometer. This report provides a detailed description of the overall experimental approach, including sample preparation as well as the data acquisition and analysis strategy for single cells. Applying this approach to the study of cultured RAW264.7 cells, we demonstrate that this method can be used to study the variation in molecular expression with cell populations and is sensitive to alterations in that expression that occurs upon lipopolysaccharide stimulation. [Figure not available: see fulltext.

  19. Single-Cell Mass Spectrometry Reveals Changes in Lipid and Metabolite Expression in RAW 264.7 Cells upon Lipopolysaccharide Stimulation

    Science.gov (United States)

    Yang, Bo; Patterson, Nathan Heath; Tsui, Tina; Caprioli, Richard M.; Norris, Jeremy L.

    2018-03-01

    It has been widely recognized that individual cells that exist within a large population of cells, even if they are genetically identical, can have divergent molecular makeups resulting from a variety of factors, including local environmental factors and stochastic processes within each cell. Presently, numerous approaches have been described that permit the resolution of these single-cell expression differences for RNA and protein; however, relatively few techniques exist for the study of lipids and metabolites in this manner. This study presents a methodology for the analysis of metabolite and lipid expression at the level of a single cell through the use of imaging mass spectrometry on a high-performance Fourier transform ion cyclotron resonance mass spectrometer. This report provides a detailed description of the overall experimental approach, including sample preparation as well as the data acquisition and analysis strategy for single cells. Applying this approach to the study of cultured RAW264.7 cells, we demonstrate that this method can be used to study the variation in molecular expression with cell populations and is sensitive to alterations in that expression that occurs upon lipopolysaccharide stimulation. [Figure not available: see fulltext.

  20. p53 regulates the proliferation, differentiation and spontaneous transformation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Armesilla-Diaz, Alejandro, E-mail: aarmesilla@cib.csic.es [Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biologicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid (Spain); Elvira, Gema; Silva, Augusto [Department of Cellular and Molecular Physiopathology, Centro de Investigaciones Biologicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid (Spain)

    2009-12-10

    Mesenchymal stem cells (MSC) have been extensively studied and gained wide popularity due to their therapeutic potential. Spontaneous transformation of MSC, from both human and murine origin, has been reported in many studies. MSC transformation depends on the culture conditions, the origin of the cells and the time on culture; however, the precise biological characteristics involved in this process have not been fully defined yet. In this study, we investigated the role of p53 in the biology and transformation of murine bone marrow (BM)-derived MSC. We demonstrate that the MSC derived from p53KO mice showed an augmented proliferation rate, a shorter doubling time and also morphologic and phenotypic changes, as compared to MSC derived from wild-type animals. Furthermore, the MSC devoid of p53 had an increased number of cells able to generate colonies. In addition, not only proliferation but also MSC differentiation is controlled by p53 since its absence modifies the speed of the process. Moreover, genomic instability, changes in the expression of c-myc and anchorage independent growth were also observed in p53KO MSC. In addition, the absence of p53 implicates the spontaneous transformation of MSC in long-term cultures. Our results reveal that p53 plays a central role in the biology of MSC.

  1. The contribution of heavy metals in cigarette smoke condensate to malignant transformation of breast epithelial cells and in vivo initiation of neoplasia through induction of a PI3K–AKT–NFκB cascade

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, Purusottam; Preet, Ranjan; Das, Dipon; Satapathy, Shakti Ranjan [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Siddharth, Sumit [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Department of Infection Biology, Institute of Life Science, Nalco Square, Bhubaneswar, Orissa 751021 (India); Choudhuri, Tathagata [Department of Infection Biology, Institute of Life Science, Nalco Square, Bhubaneswar, Orissa 751021 (India); Wyatt, Michael D. [Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC (United States); Kundu, Chanakya Nath, E-mail: cnkundu@gmail.com [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India)

    2014-01-01

    Cigarette smoking is a crucial factor in the development and progression of multiple cancers including breast. Here, we report that repeated exposure to a fixed, low dose of cigarette smoke condensate (CSC) prepared from Indian cigarettes is capable of transforming normal breast epithelial cells, MCF-10A, and delineate the biochemical basis for cellular transformation. CSC transformed cells (MCF-10A-Tr) were capable of anchorage-independent growth, and their anchorage dependent growth and colony forming ability were higher compared to the non-transformed MCF-10A cells. Increased expression of biomarkers representative of oncogenic transformation (NRP-1, Nectin-4), and anti-apoptotic markers (PI3K, AKT, NFκB) were also noted in the MCF-10A-Tr cells. Short tandem repeat (STR) profiling of MCF-10A and MCF-10A-Tr cells revealed that transformed cells acquired allelic variation during transformation, and had become genetically distinct. MCF-10A-Tr cells formed solid tumors when implanted into the mammary fat pads of Balb/c mice. Data revealed that CSC contained approximately 1.011 μg Cd per cigarette equivalent, and Cd (0.0003 μg Cd/1 × 10{sup 7} cells) was also detected in the lysates from MCF-10A cells treated with 25 μg/mL CSC. In similar manner to CSC, CdCl{sub 2} treatment in MCF-10A cells caused anchorage independent colony growth, higher expression of oncogenic proteins and increased PI3K–AKT–NFκB protein expression. An increase in the expression of PI3K–AKT–NFκB was also noted in the mice xenografts. Interestingly, it was noted that CSC and CdCl{sub 2} treatment in MCF-10A cells increased ROS. Collectively, results suggest that heavy metals present in cigarettes of Indian origin may substantially contribute to tumorigenesis by inducing intercellular ROS accumulation and increased expression of PI3K, AKT and NFκB proteins. - Highlights: • Repeated exposure of CSC causes malignant transformation in MCF-10A. • MCF-10A-Tr cells showed a distinct

  2. The contribution of heavy metals in cigarette smoke condensate to malignant transformation of breast epithelial cells and in vivo initiation of neoplasia through induction of a PI3K–AKT–NFκB cascade

    International Nuclear Information System (INIS)

    Mohapatra, Purusottam; Preet, Ranjan; Das, Dipon; Satapathy, Shakti Ranjan; Siddharth, Sumit; Choudhuri, Tathagata; Wyatt, Michael D.; Kundu, Chanakya Nath

    2014-01-01

    Cigarette smoking is a crucial factor in the development and progression of multiple cancers including breast. Here, we report that repeated exposure to a fixed, low dose of cigarette smoke condensate (CSC) prepared from Indian cigarettes is capable of transforming normal breast epithelial cells, MCF-10A, and delineate the biochemical basis for cellular transformation. CSC transformed cells (MCF-10A-Tr) were capable of anchorage-independent growth, and their anchorage dependent growth and colony forming ability were higher compared to the non-transformed MCF-10A cells. Increased expression of biomarkers representative of oncogenic transformation (NRP-1, Nectin-4), and anti-apoptotic markers (PI3K, AKT, NFκB) were also noted in the MCF-10A-Tr cells. Short tandem repeat (STR) profiling of MCF-10A and MCF-10A-Tr cells revealed that transformed cells acquired allelic variation during transformation, and had become genetically distinct. MCF-10A-Tr cells formed solid tumors when implanted into the mammary fat pads of Balb/c mice. Data revealed that CSC contained approximately 1.011 μg Cd per cigarette equivalent, and Cd (0.0003 μg Cd/1 × 10 7 cells) was also detected in the lysates from MCF-10A cells treated with 25 μg/mL CSC. In similar manner to CSC, CdCl 2 treatment in MCF-10A cells caused anchorage independent colony growth, higher expression of oncogenic proteins and increased PI3K–AKT–NFκB protein expression. An increase in the expression of PI3K–AKT–NFκB was also noted in the mice xenografts. Interestingly, it was noted that CSC and CdCl 2 treatment in MCF-10A cells increased ROS. Collectively, results suggest that heavy metals present in cigarettes of Indian origin may substantially contribute to tumorigenesis by inducing intercellular ROS accumulation and increased expression of PI3K, AKT and NFκB proteins. - Highlights: • Repeated exposure of CSC causes malignant transformation in MCF-10A. • MCF-10A-Tr cells showed a distinct STR profile and

  3. Transforming growth factor-β1 regulates fibronectin isoform expression and splicing factor SRp40 expression during ATDC5 chondrogenic maturation

    International Nuclear Information System (INIS)

    Han Fei; Gilbert, James R.; Harrison, Gerald; Adams, Christopher S.; Freeman, Theresa; Tao Zhuliang; Zaka, Raihana; Liang Hongyan; Williams, Charlene; Tuan, Rocky S.; Norton, Pamela A.; Hickok, Noreen J.

    2007-01-01

    Fibronectin (FN) isoform expression is altered during chondrocyte commitment and maturation, with cartilage favoring expression of FN isoforms that includes the type II repeat extra domain B (EDB) but excludes extra domain A (EDA). We and others have hypothesized that the regulated splicing of FN mRNAs is necessary for the progression of chondrogenesis. To test this, we treated the pre-chondrogenic cell line ATDC5 with transforming growth factor-β1, which has been shown to modulate expression of the EDA and EDB exons, as well as the late markers of chondrocyte maturation; it also slightly accelerates the early acquisition of a sulfated proteoglycan matrix without affecting cell proliferation. When chondrocytes are treated with TGF-β1, the EDA exon is preferentially excluded at all times whereas the EDB exon is relatively depleted at early times. This regulated alternative splicing of FN correlates with the regulation of alternative splicing of SRp40, a splicing factor facilitating inclusion of the EDA exon. To determine if overexpression of the SRp40 isoforms altered FN and FN EDA organization, cDNAs encoding these isoforms were overexpressed in ATDC5 cells. Overexpression of the long-form of SRp40 yielded an FN organization similar to TGF-β1 treatment; whereas overexpression of the short form of SRp40 (which facilitates EDA inclusion) increased formation of long-thick FN fibrils. Therefore, we conclude that the effects of TGF-β1 on FN splicing during chondrogenesis may be largely dependent on its effect on SRp40 isoform expression

  4. Gene Expression Music Algorithm-Based Characterization of the Ewing Sarcoma Stem Cell Signature

    Directory of Open Access Journals (Sweden)

    Martin Sebastian Staege

    2016-01-01

    Full Text Available Gene Expression Music Algorithm (GEMusicA is a method for the transformation of DNA microarray data into melodies that can be used for the characterization of differentially expressed genes. Using this method we compared gene expression profiles from endothelial cells (EC, hematopoietic stem cells, neuronal stem cells, embryonic stem cells (ESC, and mesenchymal stem cells (MSC and defined a set of genes that can discriminate between the different stem cell types. We analyzed the behavior of public microarray data sets from Ewing sarcoma (“Ewing family tumors,” EFT cell lines and biopsies in GEMusicA after prefiltering DNA microarray data for the probe sets from the stem cell signature. Our results demonstrate that individual Ewing sarcoma cell lines have a high similarity to ESC or EC. Ewing sarcoma cell lines with inhibited Ewing sarcoma breakpoint region 1-Friend leukemia virus integration 1 (EWSR1-FLI1 oncogene retained the similarity to ESC and EC. However, correlation coefficients between GEMusicA-processed expression data between EFT and ESC decreased whereas correlation coefficients between EFT and EC as well as between EFT and MSC increased after knockdown of EWSR1-FLI1. Our data support the concept of EFT being derived from cells with features of embryonic and endothelial cells.

  5. Modulation of GLO1 Expression Affects Malignant Properties of Cells

    Directory of Open Access Journals (Sweden)

    Antje Hutschenreuther

    2016-12-01

    Full Text Available The energy metabolism of most tumor cells relies on aerobic glycolysis (Warburg effect characterized by an increased glycolytic flux that is accompanied by the increased formation of the cytotoxic metabolite methylglyoxal (MGO. Consequently, the rate of detoxification of this reactive glycolytic byproduct needs to be increased in order to prevent deleterious effects to the cells. This is brought about by an increased expression of glyoxalase 1 (GLO1 that is the rate-limiting enzyme of the MGO-detoxifying glyoxalase system. Here, we overexpressed GLO1 in HEK 293 cells and silenced it in MCF-7 cells using shRNA. Tumor-related properties of wild type and transformed cells were compared and key glycolytic enzyme activities assessed. Furthermore, the cells were subjected to hypoxic conditions to analyze the impact on cell proliferation and enzyme activities. Our results demonstrate that knockdown of GLO1 in the cancer cells significantly reduced tumor-associated properties such as migration and proliferation, whereas no functional alterations where found by overexpression of GLO1 in HEK 293 cells. In contrast, hypoxia caused inhibition of cell growth of all cells except of those overexpressing GLO1. Altogether, we conclude that GLO1 on one hand is crucial to maintaining tumor characteristics of malignant cells, and, on the other hand, supports malignant transformation of cells in a hypoxic environment when overexpressed.

  6. Immunoreactive transforming growth factor alpha and epidermal growth factor in oral squamous cell carcinomas

    DEFF Research Database (Denmark)

    Therkildsen, M H; Poulsen, Steen Seier; Bretlau, P

    1993-01-01

    Forty oral squamous cell carcinomas have been investigated immunohistochemically for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF). The same cases were recently characterized for the expression of EGF-receptors. TGF-alpha was detected...... previous results confirms the existence of TGF-alpha, EGF, and EGF-receptors in the majority of oral squamous cell carcinomas and their metastases......., the cells above the basal cell layer were positive for both TGF-alpha and EGF. The same staining pattern was observed in oral mucosa obtained from healthy persons. In moderately to well differentiated carcinomas, the immunoreactivity was mainly confined to the cytologically more differentiated cells, thus...

  7. Neoplastic cell transformation by high-LET radiation - Molecular mechanisms

    Science.gov (United States)

    Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

    1989-01-01

    Quantitative data were collected on dose-response curves of cultured mouse-embryo cells (C3H10T1/2) irradiated with heavy ions of various charges and energies. Results suggests that two breaks formed on DNA within 80 A may cause cell transformation and that two DNA breaks formed within 20 A may be lethal. From results of experiments with restriction enzymes which produce DNA damages at specific sites, it was found that DNA double strand breaks are important primary lesions for radiogenic cell transformation and that blunt-ended double-strand breaks can form lethal as well as transformational damages due to misrepair or incomplete repair in the cell. The RBE-LET relationship for high-LET radiation is similar to that for HGPRT locus mutation, chromosomal deletion, and cell transformation, indicating that common lesions may be involved in these radiation effects.

  8. Malignant transformation of diploid human fibroblasts by transfection of oncogenes

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, J.J.

    1992-01-01

    This document consist of brief reports prepared by postdoctoral students supported by the project, each describing his accomplishments under the grant. Topics include (1) Malignant Transformation of MSU-1. 1 Cells by Gamma Radiation, (2) Correlation between Levels of ras Expression and Presence of Transformed Phenotypes Including Tumorigenicity, Using a Modulatable Promoter, (3) Relation between Specific rad Oncogene Expression, (4) Correlation of Genetic Changes in Fibroblastic Tumors with Malignancies, (5)Transformation of MSU-1.1 Cells by sis Oncogene, (6) Malignant Transformation of MSU-1.0 Cells, (7) Correlation of Urokinase Plasminogen Activation (mu-PA) with Malignant Phenotype, (8)Two Dimensional Gel Electrophoresis Studies of the Proteins of the Major Cell Strains of the MSU-1 Family of Cells, and (9) Correlation between Proteinase Activity Levels and Malignancy.

  9. Malignant transformation of diploid human fibroblasts by transfection of oncogenes

    International Nuclear Information System (INIS)

    McCormick, J.J.

    1992-01-01

    This document consist of brief reports prepared by postdoctoral students supported by the project, each describing his accomplishments under the grant. Topics include (1) Malignant Transformation of MSU-1. 1 Cells by Gamma Radiation, (2) Correlation between Levels of ras Expression and Presence of Transformed Phenotypes Including Tumorigenicity, Using a Modulatable Promoter, (3) Relation between Specific rad Oncogene Expression, (4) Correlation of Genetic Changes in Fibroblastic Tumors with Malignancies, (5)Transformation of MSU-1.1 Cells by sis Oncogene, (6) Malignant Transformation of MSU-1.0 Cells, (7) Correlation of Urokinase Plasminogen Activation (mu-PA) with Malignant Phenotype, (8)Two Dimensional Gel Electrophoresis Studies of the Proteins of the Major Cell Strains of the MSU-1 Family of Cells, and (9) Correlation between Proteinase Activity Levels and Malignancy

  10. Transforming growth factor β-activated kinase 1 negatively regulates interleukin-1α-induced stromal-derived factor-1 expression in vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Li, Wei [Department of Gerontology, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Zheng, Qichang [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Qin, Tao [Department of Hepatobiliary Pancreatic Surgery, People' s Hospital of Zhengzhou University, School of Medicine, Zhengzhou University, Zhengzhou 450003 (China); Wang, Kun; Li, Jinjin; Guo, Bing; Yu, Qihong; Wu, Yuzhe; Gao, Yang; Cheng, Xiang; Hu, Shaobo; Kumar, Stanley Naveen [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China); Liu, Sanguang, E-mail: sanguang1998@sina.com [Department of Hepatobiliary Surgery, The Second Hospital, Hebei Medical University, Shijiazhuang 050000 (China); Song, Zifang, E-mail: zsong@hust.edu.cn [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huangzhong University of Science and Technology, Wuhan 430022 (China)

    2015-07-17

    Stromal-derived Factor-1 (SDF-1) derived from vascular smooth muscle cells (VSMCs) contributes to vascular repair and remodeling in various vascular diseases. In this study, the mechanism underlying regulation of SDF-1 expression by interleukin-1α (IL-1α) was investigated in primary rat VSMCs. We found IL-1α promotes SDF-1 expression by up-regulating CCAAT-enhancer-binding protein β (C/EBPβ) in an IκB kinase β (IKKβ) signaling-dependent manner. Moreover, IL-1α-induced expression of C/EBPβ and SDF-1 was significantly potentiated by knockdown of transforming growth factor β-activated kinase 1 (TAK1), an upstream activator of IKKβ signaling. In addition, we also demonstrated that TAK1/p38 mitogen-activated protein kinase (p38 MAPK) signaling exerted negative effect on IL-1α-induced expression of C/EBPβ and SDF-1 through counteracting ROS-dependent up-regulation of nuclear factor erythroid 2-related factor 2 (NRF2). In conclusion, TAK1 acts as an important regulator of IL-1α-induced SDF-1 expression in VSMCs, and modulating activity of TAK1 may serve as a potential strategy for modulating vascular repair and remodeling. - Highlights: • IL-1α induces IKKβ signaling-dependent SDF-1 expression by up-regulating C/EBPβ. • Activation of TAK1 by IL-1α negatively regulates C/EBPβ-dependent SDF-1 expression. • IL-1α-induced TAK1/p38 MAPK signaling counteracts ROS-dependent SDF-1 expression. • TAK1 counteracts IL-1α-induced SDF-1 expression by attenuating NRF2 up-regulation.

  11. Transforming growth factor β-activated kinase 1 negatively regulates interleukin-1α-induced stromal-derived factor-1 expression in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Yang, Bin; Li, Wei; Zheng, Qichang; Qin, Tao; Wang, Kun; Li, Jinjin; Guo, Bing; Yu, Qihong; Wu, Yuzhe; Gao, Yang; Cheng, Xiang; Hu, Shaobo; Kumar, Stanley Naveen; Liu, Sanguang; Song, Zifang

    2015-01-01

    Stromal-derived Factor-1 (SDF-1) derived from vascular smooth muscle cells (VSMCs) contributes to vascular repair and remodeling in various vascular diseases. In this study, the mechanism underlying regulation of SDF-1 expression by interleukin-1α (IL-1α) was investigated in primary rat VSMCs. We found IL-1α promotes SDF-1 expression by up-regulating CCAAT-enhancer-binding protein β (C/EBPβ) in an IκB kinase β (IKKβ) signaling-dependent manner. Moreover, IL-1α-induced expression of C/EBPβ and SDF-1 was significantly potentiated by knockdown of transforming growth factor β-activated kinase 1 (TAK1), an upstream activator of IKKβ signaling. In addition, we also demonstrated that TAK1/p38 mitogen-activated protein kinase (p38 MAPK) signaling exerted negative effect on IL-1α-induced expression of C/EBPβ and SDF-1 through counteracting ROS-dependent up-regulation of nuclear factor erythroid 2-related factor 2 (NRF2). In conclusion, TAK1 acts as an important regulator of IL-1α-induced SDF-1 expression in VSMCs, and modulating activity of TAK1 may serve as a potential strategy for modulating vascular repair and remodeling. - Highlights: • IL-1α induces IKKβ signaling-dependent SDF-1 expression by up-regulating C/EBPβ. • Activation of TAK1 by IL-1α negatively regulates C/EBPβ-dependent SDF-1 expression. • IL-1α-induced TAK1/p38 MAPK signaling counteracts ROS-dependent SDF-1 expression. • TAK1 counteracts IL-1α-induced SDF-1 expression by attenuating NRF2 up-regulation

  12. Exit of pediatric pre-B acute lymphoblastic leukaemia cells from the bone marrow to the peripheral blood is not associated with cell maturation or alterations in gene expression

    Directory of Open Access Journals (Sweden)

    Wiebe Thomas

    2008-08-01

    Full Text Available Abstract Background Childhood pre-B acute lymphoblastic leukemia (ALL is a bone marrow (BM derived disease, which often disseminates out of the BM cavity, where malignant cells to a variable degree can be found circulating in the peripheral blood (PB. Normal pre-B cells are absolutely dependent on BM stroma for survival and differentiation. It is not known whether transformed pre-B ALL cells retain any of this dependence, which possibly could impact on drug sensitivity or MRD measurements. Results Pre-B ALL cells, highly purified by a novel method using surface expression of CD19 and immunoglobulin light chains, from BM and PB show a very high degree of similarity in gene expression patterns, with differential expression of vascular endothelial growth factor (VEGF as a notable exception. In addition, the cell sorting procedure revealed that in 2 out of five investigated patients, a significant fraction of the malignant cells had matured beyond the pre-B cell stage. Conclusion The transition of ALL cells from the BM into the circulation does not demand, or result in, major changes of gene expression pattern. This might indicate an independence of BM stroma on the part of transformed pre-B cells, which contrasts with that of their normal counterparts.

  13. Nestin expression in the cell lines derived from glioblastoma multiforme

    International Nuclear Information System (INIS)

    Veselska, Renata; Kuglik, Petr; Cejpek, Pavel; Svachova, Hana; Neradil, Jakub; Loja, Tomas; Relichova, Jirina

    2006-01-01

    Nestin is a protein belonging to class VI of intermediate filaments that is produced in stem/progenitor cells in the mammalian CNS during development and is consecutively replaced by other intermediate filament proteins (neurofilaments, GFAP). Down-regulated nestin may be re-expressed in the adult organism under certain pathological conditions (brain injury, ischemia, inflammation, neoplastic transformation). Our work focused on a detailed study of the nestin cytoskeleton in cell lines derived from glioblastoma multiforme, because re-expression of nestin together with down-regulation of GFAP has been previously reported in this type of brain tumor. Two cell lines were derived from the tumor tissue of patients treated for glioblastoma multiforme. Nestin and other cytoskeletal proteins were visualized using imunocytochemical methods: indirect immunofluorescence and immunogold-labelling. Using epifluorescence and confocal microscopy, we described the morphology of nestin-positive intermediate filaments in glioblastoma cells of both primary cultures and the derived cell lines, as well as the reorganization of nestin during mitosis. Our most important result came through transmission electron microscopy and provided clear evidence that nestin is present in the cell nucleus. Detailed information concerning the pattern of the nestin cytoskeleton in glioblastoma cell lines and especially the demonstration of nestin in the nucleus represent an important background for further studies of nestin re-expression in relationship to tumor malignancy and invasive potential

  14. Long-term in vitro, cell-type-specific genome-wide reprogramming of gene expression

    International Nuclear Information System (INIS)

    Hakelien, Anne-Mari; Gaustad, Kristine G.; Taranger, Christel K.; Skalhegg, Bjorn S.; Kuentziger, Thomas; Collas, Philippe

    2005-01-01

    We demonstrate a cell extract-based, genome-wide and heritable reprogramming of gene expression in vitro. Kidney epithelial 293T cells have previously been shown to take on T cell properties following a brief treatment with an extract of Jurkat T cells. We show here that 293T cells exposed for 1 h to a Jurkat cell extract undergo genome-wide, target cell-type-specific and long-lasting transcriptional changes. Microarray analyses indicate that on any given week after extract treatment, ∼2500 genes are upregulated >3-fold, of which ∼900 are also expressed in Jurkat cells. Concomitantly, ∼1500 genes are downregulated or repressed, of which ∼500 are also downregulated in Jurkat cells. Gene expression changes persist for over 30 passages (∼80 population doublings) in culture. Target cell-type specificity of these changes is shown by the lack of activation or repression of Jurkat-specific genes by extracts of 293T cells or carcinoma cells. Quantitative RT-PCR analysis confirms the long-term transcriptional activation of genes involved in key T cell functions. Additionally, growth of cells in suspended aggregates, expression of CD3 and CD28 T cell surface markers, and interleukin-2 secretion by 293T cells treated with extract of adult peripheral blood T cells illustrate a functional nuclear reprogramming. Therefore, target cell-type-specific and heritable changes in gene expression, and alterations in cell function, can be promoted by extracts derived from transformed cells as well as from adult primary cells

  15. Cytogenetic characterization and H-ras associated transformation of immortalized human mammary epithelial cells

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    Larivee Siobhan

    2006-05-01

    Full Text Available Abstract Introduction Immortalization is a key step in malignant transformation, but immortalization alone is insufficient for transformation. Human mammary epithelial cell (HMEC transformation is a complex process that requires additional genetic changes beyond immortalization and can be accomplished in vitro by accumulation of genetic changes and expression of H-ras. Methods HMEC were immortalized by serial passaging and transduction with the catalytic subunit of the human telomerase gene (hTERT. The immortalized cells were passaged in vitro and studied by a combination of G- banding and Spectral Karyotyping (SKY. H-ras transduced, hTERT immortalized cells were cloned in soft agar and injected into nude mice. Extensive analysis was performed on the tumors that developed in nude mice, including immunohistochemistry and western blotting. Results Immortal HMEC alone were not tumorigenic in γ-irradiated nude mice and could not grow in soft agar. Late passage hTERT immortalized HMEC from a donor transduced with a retroviral vector containing the mutant, autoactive, human H-ras61L gene acquired anchorage independent growth properties and the capacity for tumorigenic growth in vivo. The tumors that developed in the nude mice were poorly differentiated epithelial carcinomas that continued to overexpress ras. These cells were resistant to doxorubicin mediated G1/S phase arrest but were sensitive to treatment with a farnesyltransferase inhibitor. Conclusion Some of the cytogenetic changes are similar to what is observed in premalignant and malignant breast lesions. Despite these changes, late passage immortal HMEC are not tumorigenic and could only be transformed with overexpression of a mutant H-ras oncogene.

  16. Arsenite induces cell transformation by reactive oxygen species, AKT, ERK1/2, and p70S6K1

    International Nuclear Information System (INIS)

    Carpenter, Richard L.; Jiang, Yue; Jing, Yi; He, Jun; Rojanasakul, Yon; Liu, Ling-Zhi; Jiang, Bing-Hua

    2011-01-01

    Highlights: ► Chronic exposure to arsenite induces cell proliferation and transformation. ► Arsenite-induced transformation increases ROS production and downstream signalings. ► Inhibition of ROS levels via catalase reduces arsenite-induced cell transformation. ► Interruption of AKT, ERK, or p70S6K1 inhibits arsenite-induced cell transformation. -- Abstract: Arsenic is naturally occurring element that exists in both organic and inorganic formulations. The inorganic form arsenite has a positive association with development of multiple cancer types. There are significant populations throughout the world with high exposure to arsenite via drinking water. Thus, human exposure to arsenic has become a significant public health problem. Recent evidence suggests that reactive oxygen species (ROS) mediate multiple changes to cell behavior after acute arsenic exposure, including activation of proliferative signaling and angiogenesis. However, the role of ROS in mediating cell transformation by chronic arsenic exposure is unknown. We found that cells chronically exposed to sodium arsenite increased proliferation and gained anchorage-independent growth. This cell transformation phenotype required constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. We also observed these cells constitutively produce ROS, which was required for the constitutive activation of AKT, ERK1/2, mTOR, and p70S6K1. Suppression of ROS levels by forced expression of catalase also reduced cell proliferation and anchorage-independent growth. These results indicate cell transformation induced by chronic arsenic exposure is mediated by increased cellular levels of ROS, which mediates activation of AKT, ERK1/2, and p70S6K1.

  17. Plastid-expressed betaine aldehyde dehydrogenase gene in carrot cultured cells, roots, and leaves confers enhanced salt tolerance.

    Science.gov (United States)

    Kumar, Shashi; Dhingra, Amit; Daniell, Henry

    2004-09-01

    Salinity is one of the major factors that limits geographical distribution of plants and adversely affects crop productivity and quality. We report here high-level expression of betaine aldehyde dehydrogenase (BADH) in cultured cells, roots, and leaves of carrot (Daucus carota) via plastid genetic engineering. Homoplasmic transgenic plants exhibiting high levels of salt tolerance were regenerated from bombarded cell cultures via somatic embryogenesis. Transformation efficiency of carrot somatic embryos was very high, with one transgenic event per approximately seven bombarded plates under optimal conditions. In vitro transgenic carrot cells transformed with the badh transgene were visually green in color when compared to untransformed carrot cells, and this offered a visual selection for transgenic lines. BADH enzyme activity was enhanced 8-fold in transgenic carrot cell cultures, grew 7-fold more, and accumulated 50- to 54-fold more betaine (93-101 micromol g(-1) dry weight of beta-Ala betaine and Gly betaine) than untransformed cells grown in liquid medium containing 100 mm NaCl. Transgenic carrot plants expressing BADH grew in the presence of high concentrations of NaCl (up to 400 mm), the highest level of salt tolerance reported so far among genetically modified crop plants. BADH expression was 74.8% in non-green edible parts (carrots) containing chromoplasts, and 53% in proplastids of cultured cells when compared to chloroplasts (100%) in leaves. Demonstration of plastid transformation via somatic embryogenesis utilizing non-green tissues as recipients of foreign DNA for the first time overcomes two of the major obstacles in extending this technology to important crop plants.

  18. Subcutaneous administration of polymerized type I collagen downregulates interleukin (IL)-17A, IL-22 and transforming growth factor-β1 expression, and increases Foxp3-expressing cells in localized scleroderma.

    Science.gov (United States)

    Furuzawa-Carballeda, J; Ortíz-Ávalos, M; Lima, G; Jurado-Santa Cruz, F; Llorente, L

    2012-08-01

    Localized scleroderma (LS) is a disfiguring inflammatory autoimmune disease of the skin and underlying tissue. As in systemic sclerosis, a key feature is the presence of T cells in inflammatory lesions. To evaluate the effect of polymerized type I collagen vs. methylprednisolone (MP) in LS, and to determine the influence of this polymerized collagen (PC) on CD4+ peripheral T cells expressing interleukin (IL)-4, IL-17A, interferon-γ and Forkhead box protein (Foxp)3, and on cells expressing transforming growth factor (TGF)-β1, IL-17A, IL-22 and Foxp3 in the skin. In total, 16 patients with LS were treated for 3 months with monthly subcutaneous intralesional injections of 0.1 mL MP (giving a total dose of 20 mg/mL each month) and 15 patients were treated, with weekly subcutaneous intralesional injections of PC, ranging from 0.2 mL (equivalent to 1.66 mg collagen) for a lesion of 50 mm in size, up to a maximum of 1.0 mL (8.3 mg collagen) for a lesion > 100 mm in size, and followed up for a further 6 months. Skin biopsies were obtained from lesions at baseline (before treatment) and 9 months later (6 months after treatment end). Tissue sections were evaluated by histology and immunohistochemistry (IL-17A, IL-22, TGF-β1 and Foxp3). CD4+ T-cell subsets were determined in peripheral blood by flow cytometry. Abnormal tissue architecture was seen in the biopsies taken from patients treated with MP, whereas the PC treatment restored normal skin architecture. PC downregulated pro-inflammatory/profibrotic cytokine expression in peripheral cells, and upregulated the number of regulatory T cells (Tregs) in skin. PC was safe and well tolerated. PC is not only an antifibrotic/fibrolytic agent but also an immunomodulator biodrug that restores the balance between T helper (Th)1, Th2, Th17 and Tregs, downregulates production of pro-inflammatory or profibrogenic cytokines (IL-17A, IL-22 and TGF-β1), and renews skin architecture, without adverse effects. © The Author(s). CED

  19. Involvement of up-regulated Necl-5/Tage4/PVR/CD155 in the loss of contact inhibition in transformed NIH3T3 cells

    International Nuclear Information System (INIS)

    Minami, Yukiko; Ikeda, Wataru; Kajita, Mihoko; Fujito, Tsutomu; Monden, Morito; Takai, Yoshimi

    2007-01-01

    Normal cells show contact inhibition of cell movement and proliferation, but this is lost following transformation. We found that Necl-5, originally identified as a poliovirus receptor and up-regulated in many cancer cells, enhances growth factor-induced cell movement and proliferation. We showed that when cells contact other cells, Necl-5 interacts in trans with nectin-3 and is removed by endocytosis from the cell surface, resulting in a reduction of cell movement and proliferation. We show here that up-regulation of the gene encoding Necl-5 by the oncogene V12-Ki-Ras causes enhanced cell movement and proliferation. Upon cell-cell contact, de novo synthesis of Necl-5 exceeds the rate of Necl-5 endocytosis, eventually resulting in a net increase in the amount of Necl-5 at the cell surface. In addition, expression of the gene encoding nectin-3 is markedly reduced in transformed cells. Thus, up-regulation of Necl-5 following transformation contributes to the loss of contact inhibition in transformed cells

  20. Inhibition of Geranylgeranyl Transferase-I Decreases Cell Viability of HTLV-1-Transformed Cells

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    Cynthia A. Pise-Masison

    2011-10-01

    Full Text Available Human T-cell leukemia virus type-1 (HTLV-1 is the etiological agent of adult T-cell leukemia (ATL, an aggressive and highly chemoresistant malignancy. Rho family GTPases regulate multiple signaling pathways in tumorigenesis: cytoskeletal organization, transcription, cell cycle progression, and cell proliferation. Geranylgeranylation of Rho family GTPases is essential for cell membrane localization and activation of these proteins. It is currently unknown whether HTLV-1-transformed cells are preferentially sensitive to geranylgeranylation inhibitors, such as GGTI-298. In this report, we demonstrate that GGTI-298 decreased cell viability and induced G2/M phase accumulation of HTLV-1-transformed cells, independent of p53 reactivation. HTLV-1-LTR transcriptional activity was inhibited and Tax protein levels decreased following treatment with GGTI-298. Furthermore, GGTI-298 decreased activation of NF-κB, a downstream target of Rho family GTPases. These studies suggest that protein geranylgeranylation contributes to dysregulation of cell survival pathways in HTLV-1-transformed cells.

  1. Construction of rat beta defensin-2 eukaryotic expression vector and expression in the transfected rat corneal epithelial cell

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    Jing Dan

    2017-03-01

    Full Text Available AIM: To construct a recombinant eukaryotic expression vector of rat beta defensin-2(rBD-2, transfect it into the rat corneal epithelial cells with lipofection, determine the expression of target gene in the transfected cells, and discuss the potentiality of recombinant plasmid expressed in corneal epithelial cells, hoping to provide an experimental foundation for further study on the antimicrobial activity of rBD-2 in vitro and in vivo and to assess the probability of defensins as a new application for infectious corneal diseases in the future. METHODS: The synthetic rBD-2 DNA fragment was inserted between the XhoI and BamHI restriction enzyme cutting sites of eukaryotic expression vector pIRES2-ZsGreen1 to construct the recombinant plasmid pIRES2-ZsGreen1-rBD-2, then transformed it into E.coli DH5α, positive clones were screened by kanamycin and identified with restriction endonucleases and sequencing analysis. Transfection into the rat corneal epithelial cells was performed by lipofection. Then the experiment was divided into three groups: rat corneal epithelial cell was transfected with the recombinant plasmid pIRES2- ZsGreen1-rBD-2, rat corneal epithelial cell was transfected with the empty plasmid pIRES2-ZsGreen1 and the non-transfected group. The inverted fluorescence microscope was used to observe the transfection process. At last, the level of rBD-2 mRNA expressed in the transfected cells and the control groups are compared by the real-time fluoresence relative quantitative PCR. RESULTS: The recombinant eukaryotic expression vector of pIRES2-ZsGreen1-rBD-2 was successfully constructed. The level of rBD-2 mRNA in transfected cells was significantly higher than that in control groups through the real-time fluorescence relative quantitative PCR. CONCLUSION: The recombinant eukaryotic expression vector pIRES2-ZsGreen1-rBD-2 could be transfected into rat corneal epithelial cells, and exogenous rBD-2 gene could be transcripted into mRNA in

  2. NF-kappa B activity in T cells stably expressing the Tax protein of human T cell lymphotropic virus type I

    International Nuclear Information System (INIS)

    Lacoste, J.; Cohen, L.; Hiscott, J.

    1991-01-01

    The effect of constitutive Tax expression on the interaction of NF-κ B with its recognition sequence and on NF-κ B-dependent gene expression was examined in T lymphoid Jurkat cell lines (19D and 9J) stably transformed with a Tax expression vector. Tax expressing T cell lines contained a constitutive level of NF-κ B binding activity, detectable by mobility shift assay and uv cross-linking using a palindromic NF-κ B probe homologous to the interferon beta PRDII site. In Jurkat and NC2.10 induction with phorbol esters resulted in the appearance of new DNA binding proteins of 85, 75, and 54 kDa, whereas in Tax expressing cells the 85-kDa protein and a 92-kDa DNA binding protein were constitutively induced. Expression of Tax protein in 19D and 9J resulted in transcription of the endogenous NF-kappa B-dependent granulocyte-macrophage colony stimulating factor gene and increased basal level expression of transfected NF-kappa B-regulated promoters. Nonetheless transcription of both the endogenous and the transfected gene was inducible by PMA treatment. Tax expression in Jurkat T cells may alter the stoichiometry of NF-kappa B DNA binding proteins and thus change the expression of NF-kappa B-regulated promoters

  3. Growth factor expression pattern of homologous feeder layer for culturing buffalo embryonic stem cell-like cells.

    Science.gov (United States)

    Sharma, Ruchi; George, Aman; Kamble, Nitin M; Chauhan, Manmohan S; Singla, Suresh; Manik, Radhey S; Palta, Prabhat

    2012-01-01

    The present study examined the expression profile of buffalo fetal fibroblasts (BFF) used as a feeder layer for embryonic stem (ES) cell-like cells. The expression of important growth factors was detected in cells at different passages. Mitomycin-C inactivation increased relative expression levels of ACTIVIN-A, TGF-β1, BMP-4 and GREMLIN but not of fibroblast growth factor-2 (FGF-2). The expression level of ACTIVIN-A, transforming growth factor-β1 (TGF-β1), bone morphogenetic protein-4 (BMP-4) and FGF-2 was similar in buffalo fetal fibroblast (BFF) cultured in stem cell medium (SCM), SCM+1000IU mL(-1) leukemia inhibitory factor (LIF), SCM+5 ngmL(-1) FGF-2 or SCM+LIF+FGF-2 for 24 h whereas GREMLIN expression was higher in FGF-2-supplemented groups. In spent medium, the concentration of ACTIVIN-A was higher in FGF-2-supplemented groups whereas that of TGF-β1 was similar in SCM and LIF+FGF-2, which was higher than when either LIF or FGF-2 was used alone. Following culture of ES cell-like cells on a feeder layer for 24 h, the TGF-β1 concentration was higher with LIF+FGF-2 than with LIF or FGF-2 alone which, in turn, was higher than that in SCM. In the LIF+FGF-2 group, the concentration of TGF-β1 was lower and that of ACTIVIN-A was higher in spent medium at 24 h than at 48 h of culture. These results suggest that BFF produce signalling molecules that may help in self-renewal of buffalo ES cell-like cells.

  4. Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Weili; Xiao, Linlin; Dong, Chen; He, Mingyuan; Pan, Yan; Xie, Yuexia; Tu, Wenzhi; Fu, Jiamei; Shao, Chunlin, E-mail: clshao@shmu.edu.cn

    2014-05-09

    Highlights: • Multi-exposures of 25 mGy α-ray enhanced cell proliferation, adhesion, and invasion. • MAPK/Akt but not JNK/P66 was positively correlated with cell invasive phenotypes. • LDR of α-irradiation triggers cell malignant transformation through MAPK/Akt. - Abstract: Since the wide usage of ionizing radiation, the cancer risk of low dose radiation (LDR) (<0.1 Gy) has become attractive for a long time. However, most results are derived from epidemiologic studies on atomic-bomb survivors and nuclear accidents surrounding population, and the molecular mechanism of this risk is elusive. To explore the potential of a long-term LDR-induced malignant transformation, human bronchial epithelial cells Beas-2B were fractionally irradiated with 0.025 Gy α-particles for 8 times in total and then further cultured for 1–2 months. It was found that the cell proliferation, the abilities of adhesion and invasion, and the protein expressions of p-ERK, p-Akt, especially p-P38 were not only increased in the multiply-irradiated cells but also in their offspring 1–2 months after the final exposure, indicating high potentiality of cell malignant transformation. On opposite, the expressions of p-JNK and p-P66 were diminished in the subcultures of irradiated cells and thus may play a role of negative regulation in canceration. When the cells were transferred with p38 siRNA, the LDR-induced enhancements of cell adhesion and invasion were significantly reduced. These findings suggest that long-term LDR of α-particles could enhance the potential of malignant transformation incidence in human bronchial epithelial cells through MAPK/Akt pathway.

  5. Long-term low-dose α-particle enhanced the potential of malignant transformation in human bronchial epithelial cells through MAPK/Akt pathway

    International Nuclear Information System (INIS)

    Liu, Weili; Xiao, Linlin; Dong, Chen; He, Mingyuan; Pan, Yan; Xie, Yuexia; Tu, Wenzhi; Fu, Jiamei; Shao, Chunlin

    2014-01-01

    Highlights: • Multi-exposures of 25 mGy α-ray enhanced cell proliferation, adhesion, and invasion. • MAPK/Akt but not JNK/P66 was positively correlated with cell invasive phenotypes. • LDR of α-irradiation triggers cell malignant transformation through MAPK/Akt. - Abstract: Since the wide usage of ionizing radiation, the cancer risk of low dose radiation (LDR) (<0.1 Gy) has become attractive for a long time. However, most results are derived from epidemiologic studies on atomic-bomb survivors and nuclear accidents surrounding population, and the molecular mechanism of this risk is elusive. To explore the potential of a long-term LDR-induced malignant transformation, human bronchial epithelial cells Beas-2B were fractionally irradiated with 0.025 Gy α-particles for 8 times in total and then further cultured for 1–2 months. It was found that the cell proliferation, the abilities of adhesion and invasion, and the protein expressions of p-ERK, p-Akt, especially p-P38 were not only increased in the multiply-irradiated cells but also in their offspring 1–2 months after the final exposure, indicating high potentiality of cell malignant transformation. On opposite, the expressions of p-JNK and p-P66 were diminished in the subcultures of irradiated cells and thus may play a role of negative regulation in canceration. When the cells were transferred with p38 siRNA, the LDR-induced enhancements of cell adhesion and invasion were significantly reduced. These findings suggest that long-term LDR of α-particles could enhance the potential of malignant transformation incidence in human bronchial epithelial cells through MAPK/Akt pathway

  6. Expression of selected pathway-marker genes in human urothelial cells exposed chronically to a non-cytotoxic concentration of monomethylarsonous acid

    Directory of Open Access Journals (Sweden)

    Matthew Medeiros

    2014-01-01

    Full Text Available Bladder cancer has been associated with chronic arsenic exposure. Monomethylarsonous acid [MMA(III] is a metabolite of inorganic arsenic and has been shown to transform an immortalized urothelial cell line (UROtsa at concentrations 20-fold less than arsenite. MMA(III was used as a model arsenical to examine the mechanisms of arsenical-induced transformation of urothelium. A previous microarray analysis revealed only minor changes in gene expression at 1 and 2 months of chronic exposure to MMA(III, contrasting with substantial changes observed at 3 months of exposure. To address the lack of information between 2 and 3 months of exposure (the critical period of transformation, the expression of select pathway marker genes was measured by PCR array analysis on a weekly basis. Cell proliferation rate, anchorage-independent growth, and tumorigenicity in SCID mice were also assessed to determine the early, persistent phenotypic changes and their association with the changes in expression of these selected marker genes. A very similar pattern of alterations in these genes was observed when compared to the microarray results, and suggested that early perturbations in cell signaling cascades, immunological pathways, cytokine expression, and MAPK pathway are particularly important in driving malignant transformation. These results showed a strong association between the acquired phenotypic changes that occurred as early as 1–2 months of chronic MMA(III exposure, and the observed gene expression pattern that is indicative of the earliest stages in carcinogenesis.

  7. Spontaneous transformation of adult mesenchymal stem cells from cynomolgus macaques in vitro

    International Nuclear Information System (INIS)

    Ren, Zhenhua; Wang, Jiayin; Zhu, Wanwan; Guan, Yunqian; Zou, Chunlin; Chen, Zhiguo; Zhang, Y. Alex

    2011-01-01

    Mesenchymal stem cells (MSCs) have shown potential clinical utility in cell therapy and tissue engineering, due to their ability to proliferate as well as to differentiate into multiple lineages, including osteogenic, adipogenic, and chondrogenic specifications. Therefore, it is crucial to assess the safety of MSCs while extensive expansion ex vivo is a prerequisite to obtain the cell numbers for cell transplantation. Here we show that MSCs derived from adult cynomolgus monkey can undergo spontaneous transformation following in vitro culture. In comparison with MSCs, the spontaneously transformed mesenchymal cells (TMCs) display significantly different growth pattern and morphology, reminiscent of the characteristics of tumor cells. Importantly, TMCs are highly tumorigenic, causing subcutaneous tumors when injected into NOD/SCID mice. Moreover, no multiple differentiation potential of TMCs is observed in vitro or in vivo, suggesting that spontaneously transformed adult stem cells may not necessarily turn into cancer stem cells. These data indicate a direct transformation of cynomolgus monkey MSCs into tumor cells following long-term expansion in vitro. The spontaneous transformation of the cultured cynomolgus monkey MSCs may have important implications for ongoing clinical trials and for models of oncogenesis, thus warranting a more strict assessment of MSCs prior to cell therapy. -- Highlights: ► Spontaneous transformation of cynomolgus monkey MSCs in vitro. ► Transformed mesenchymal cells lack multipotency. ► Transformed mesenchymal cells are highly tumorigenic. ► Transformed mesenchymal cells do not have the characteristics of cancer stem cells.

  8. Podoplanin Expression Is Correlated With the Progression of Chronic Discoid Lupus Erythematosus to Lip Squamous Cell Carcinoma.

    Science.gov (United States)

    Gao, Xing; Ma, Liwei; Zhou, Zengtong; Jian, Xinchun; Liu, Wei

    2016-10-01

    Chronic lip discoid lupus erythematosus (DLE) is a potentially malignant disorder that can develop into lip squamous cell carcinoma (LSCC). Podoplanin is a specific marker for lymphatic endothelial cells and plays a role in cancer progression. The objective of this study was to determine the immunoexpression of podoplanin in samples of patients with DLE and its correlation with the risk of progression to LSCC. In a retrospective study, podoplanin expression was determined using immunohistochemistry in samples from 52 patients with DLE, including 44 patients with untransformed DLE and 8 patients with malignant transformed DLE. Ten samples of normal oral mucosa and 10 samples of LSCC were used as normal and cancer controls, respectively. The results showed that podoplanin expression was observed in 12 of 44 (27.3%) patients with untransformed DLE and in 7 of 8 (87.5%) patients with transformed DLE (P = .002). Podoplanin was not expressed in normal oral mucosa, but it was overexpressed in all of the 10 patients with LSCC. Regression analysis revealed that podoplanin expression was significantly associated with an 18.67-fold increase in the risk of malignant progression (95% confidence interval = 2.07-168.10; P = .009). In summary, podoplanin expression is significantly associated with malignant transformation of DLE into LSCC. Thus, podoplanin expression may identify a subgroup with a high risk of malignant progression of DLE. © The Author(s) 2016.

  9. Differential expression of the ufo/axl oncogene in human leukemia-lymphoma cell lines.

    Science.gov (United States)

    Challier, C; Uphoff, C C; Janssen, J W; Drexler, H G

    1996-05-01

    The ufo protein (also termed axl) is a member of a new family of receptor tyrosine kinases and is encoded by a transforming gene that was initially isolated from primary human myeloid leukemia cells by DNA-mediated transformation of NIH/3T3 cells. The ligand, Gas6, a protein S-related molecule lacking any known function yet, has recently been identified. We report the expression pattern of ufo mRNA in a panel of 76 human continuous leukemia-lymphoma cell lines. The gene was not expressed in cell lines derived from lymphoid malignancies (n=28), but transcription was seen in 3/11 myeloid, 0/6 monocytic, 9/13 erythroid and 11/18 megakaryocytic cell lines. Several cell lines were treated with phorbol ester leading to significant upregulation of the ufo message in constitutively positive cells. An apparent ufo mRNA overexpression was not found in any of the positive leukemia cell lines, but was identified in the drug-resistant subclones of the cervix carcinoma cell line HeLa. Southern blot analysis of restriction enzyme-digested genomic DNA did not provide evidence for gene amplification, but the HeLa subclones showed banding patterns suggestive of gene rearrangement. Two main ufo mRNA bands of 3.2 and 5.0 kb were identified; no differences in the half-lives (t1/2 = 2.5 h) of these two mRNA species could be identified. In summary, ufo, representing a novel type of receptor tyrosine kinase, is expressed solely in myeloid and erythro-megakaryocytic leukemias but not in lymphoid malignancies. These and previous data suggest an involvement of the ufo receptor tyrosine kinase in normal and malignant myelopoiesis; however, its exact role, if any, and mode of operation in leukemogenesis remains to be determined.

  10. Transgene Expression and Repression in Transgenic Rats Bearing the Phosphoenolpyruvate Carboxykinase-Simian Virus 40 T Antigen or the Phosphoenolpyruvate Carboxykinase-Transforming Growth Factor-α Constructs

    Science.gov (United States)

    Haas, Michael J.; Dragan, Yvonne P.; Hikita, Hiroshi; Shimel, Randee; Takimoto, Koichi; Heath, Susan; Vaughan, Jennifer; Pitot, Henry C.

    1999-01-01

    Transgenic Sprague-Dawley rats expressing either human transforming growth factor-α (TGFα) or simian virus 40 large and small T antigen (TAg), each under the control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter, were developed as an approach to the study of the promotion of hepatocarcinogenesis in the presence of a transgene regulatable by diet and/or hormones. Five lines of PEPCK-TGFα transgenic rats were established, each genetic line containing from one to several copies of the transgene per haploid genome. Two PEPCK-TAg transgenic founder rats were obtained, each with multiple copies of the transgene. Expression of the transgene was undetectable in the TGFα transgenic rats and could not be induced when the animals were placed on a high-protein, low-carbohydrate diet. The transgene was found to be highly methylated in all of these lines. No pathological alterations in the liver and intestine were observed at any time (up to 2 years) during the lives of these rats. One line of transgenic rats expressing the PEPCK-TAg transgene developed pancreatic islet cell hyperplasias and carcinomas, with few normal islets evident in the pancreas. This transgene is integrated as a hypomethylated tandem array of 10 to 12 copies on chromosome 8q11. Expression of large T antigen is highest in pancreatic neoplasms, but is also detectable in the normal brain, kidney, and liver. Mortality is most rapid in males, starting at 5 months of age and reaching 100% by 8 months. Morphologically, islet cell differentiation in the tumors ranges from poor to well differentiated, with regions of necrosis and fibrosis. Spontaneous metastasis of TAg-positive tumor cells to regional lymph nodes was observed. These studies indicate the importance of DNA methylation in the repression of specific transgenes in the rat. However, the expression of the PEPCK-TAg induces neoplastic transformation in islet cells, probably late in neuroendocrine cell differentiation. T antigen expression

  11. Study on oxidative lipid and DNA damages in the malignant transformed BEP2D cells induced by α-particle exposure

    International Nuclear Information System (INIS)

    Gou Qiao; Wang Chunyan; Zhang Cuilan; Tong Peng; Su Xu

    2012-01-01

    Objective: To investigate the mechanism of malignant transformation in human bronchial epithelial cell line BEP2D exposed to α-particles. Methods: The levels of intracellular ROS and malonaldehyde (MDA) in BEP2D, RH22 (passage 22 of α-particle-irradiated BEP2D cells) and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from the passage 35 of α-particle-irradiated BEP2D cells) were assayed with DCFH-DA and MDA kit, respectively. The expressions of 8-OH-dG and γ-H2AX in BEP2D, RH23 (passage 23 of α-particle-irradiated BEP2D cells) and BERP35T-1 cells were also measured with immunocytochemistry and immunofluorescence staining. Results: Compared to BEP2D cells, the levels of ROS (t=4.30 and 3.94, P<0.05) and MDA (t=4.89 and 15.10, P<0.05) increased in RH22 and BERP35T-1 cells. The expressions of 8-OH-dG (t=3.80 and 2.92, P<0.05) and γ-H2AX (t=7.61 and 12.67, P<0.05) in RH23 and BERP35T-1 cells were also higher than those in BEP2D cells. Conclusions: Oxidative stress induces lipid peroxidation and DNA damage leading to genomic instability, which could contribute to cellular malignant transforming process in the human bronchial epithelial cell line BEP2D with α-particle exposure. (authors)

  12. Platelet-derived stromal cell-derived factor-1 is required for the transformation of circulating monocytes into multipotential cells.

    Directory of Open Access Journals (Sweden)

    Noriyuki Seta

    Full Text Available BACKGROUND: We previously described a primitive cell population derived from human circulating CD14(+ monocytes, named monocyte-derived multipotential cells (MOMCs, which are capable of differentiating into mesenchymal and endothelial lineages. To generate MOMCs in vitro, monocytes are required to bind to fibronectin and be exposed to soluble factor(s derived from circulating CD14(- cells. The present study was conducted to identify factors that induce MOMC differentiation. METHODS: We cultured CD14(+ monocytes on fibronectin in the presence or absence of platelets, CD14(- peripheral blood mononuclear cells, platelet-conditioned medium, or candidate MOMC differentiation factors. The transformation of monocytes into MOMCs was assessed by the presence of spindle-shaped adherent cells, CD34 expression, and the potential to differentiate in vitro into mesenchymal and endothelial lineages. RESULTS: The presence of platelets or platelet-conditioned medium was required to generate MOMCs from monocytes. A screening of candidate platelet-derived soluble factors identified stromal cell-derived factor (SDF-1 as a requirement for generating MOMCs. Blocking an interaction between SDF-1 and its receptor CXCR4 inhibited MOMC generation, further confirming SDF-1's critical role in this process. Finally, circulating MOMC precursors were found to reside in the CD14(+CXCR4(high cell population. CONCLUSION: The interaction of SDF-1 with CXCR4 is essential for the transformation of circulating monocytes into MOMCs.

  13. Caveolin-1 down-regulation is required for Wnt5a-Frizzled 2 signalling in Ha-RasV12 -induced cell transformation.

    Science.gov (United States)

    Lin, Hsiu-Kuan; Lin, Hsi-Hui; Chiou, Yu-Wei; Wu, Ching-Lung; Chiu, Wen-Tai; Tang, Ming-Jer

    2018-05-01

    Caveolin-1 (Cav1) is down-regulated during MK4 (MDCK cells harbouring inducible Ha-Ras V12 gene) transformation by Ha-Ras V12 . Cav1 overexpression abrogates the Ha-Ras V12 -driven transformation of MK4 cells; however, the targeted down-regulation of Cav1 is not sufficient to mimic this transformation. Cav1-silenced cells, including MK4/shCav1 cells and MDCK/shCav1 cells, showed an increased cell area and discontinuous junction-related proteins staining. Cellular and mechanical transformations were completed when MDCK/shCav1 cells were treated with medium conditioned by MK4 cells treated with IPTG (MK4+I-CM) but not with medium conditioned by MK4 cells. Nanoparticle tracking analysis showed that Ha-Ras V12 -inducing MK4 cells increased exosome-like microvesicles release compared with their normal counterparts. The cellular and mechanical transformation activities of MK4+I-CM were abolished after heat treatment and exosome depletion and were copied by exosomes derived from MK4+I-CM (MK4+I-EXs). Wnt5a, a downstream product of Ha-Ras V12 , was markedly secreted by MK4+I-CM and MK4+I-EXs. Suppression of Wnt5a expression and secretion using the porcupine inhibitor C59 or Wnt5a siRNA inhibited the Ha-Ras V12 - and MK4+I-CM-induced transformation of MK4 cells and MDCK/shCav1 cells, respectively. Cav1 down-regulation, either by Ha-Ras V12 or targeted shRNA, increased frizzled-2 (Fzd2) protein levels without affecting its mRNA levels, suggesting a novel role of Cav1 in negatively regulating Fzd2 expression. Additionally, silencing Cav1 facilitated the internalization of MK4+I-EXs in MDCK cells. These data suggest that Cav1-dependent repression of Fzd2 and exosome uptake is potentially relevant to its antitransformation activity, which hinders the activation of Ha-Ras V12 -Wnt5a-Stat3 pathway. Altogether, these results suggest that both decreasing Cav1 and increasing exosomal Wnt5a must be implemented during Ha-Ras V12 -driven cell transformation. © 2018 The Authors

  14. Gene expression profiles in BCL11B-siRNA treated malignant T cells

    Directory of Open Access Journals (Sweden)

    Grabarczyk Piotr

    2011-05-01

    Full Text Available Abstract Background Downregulation of the B-cell chronic lymphocytic leukemia (CLL/lymphoma11B (BCL11B gene by small interfering RNA (siRNA leads to growth inhibition and apoptosis of the human T-cell acute lymphoblastic leukemia (T-ALL cell line Molt-4. To further characterize the molecular mechanism, a global gene expression profile of BCL11B-siRNA -treated Molt-4 cells was established. The expression profiles of several genes were further validated in the BCL11B-siRNA -treated Molt-4 cells and primary T-ALL cells. Results 142 genes were found to be upregulated and 109 genes downregulated in the BCL11B-siRNA -treated Molt-4 cells by microarray analysis. Among apoptosis-related genes, three pro-apoptotic genes, TNFSF10, BIK, BNIP3, were upregulated and one anti-apoptotic gene, BCL2L1 was downregulated. Moreover, the expression of SPP1 and CREBBP genes involved in the transforming growth factor (TGF-β pathway was down 16-fold. Expression levels of TNFSF10, BCL2L1, SPP1, and CREBBP were also examined by real-time PCR. A similar expression pattern of TNFSF10, BCL2L1, and SPP1 was identified. However, CREBBP was not downregulated in the BLC11B-siRNA -treated Molt-4 cells. Conclusion BCL11B-siRNA treatment altered expression profiles of TNFSF10, BCL2L1, and SPP1 in both Molt-4 T cell line and primary T-ALL cells.

  15. Altered expression of epithelial cell surface glycoconjugates and intermediate filaments at the margins of mucosal wounds

    DEFF Research Database (Denmark)

    Dabelsteen, Erik; Grøn, B.; Mandel, U.

    1998-01-01

    Alterations in cell to cell adhesion are necessary to enable the type of cell movements that are associated with epithelial wound healing and malignant invasion. Several studies of transformed cells have related epithelial cell movement to changes in the cell surface expression of the carbohydrate......-T antigen. The changes induced by wounding in the expression of collagen IV, laminin gamma2-chain (laminin-5), and laminin alpha5-chain were similar to those found in skin wounds and served to define the region of epithelial movement. This region was found to show a marked increase in staining for both...... epithelium, a pattern of expression similar to K16, which was also strongly upregulated in both the outgrowth and the adjacent nonwounded epithelium. These findings provide further support for an influence of such carbohydrate structures on the migratory behavior of epithelial cells....

  16. Ectopic expression of PTTG1/securin promotes tumorigenesis in human embryonic kidney cells

    Directory of Open Access Journals (Sweden)

    Malik Mohammed T

    2005-01-01

    Full Text Available Abstract Background Pituitary tumor transforming gene1 (PTTG1 is a novel oncogene that is expressed in most tumors. It encodes a protein that is primarily involved in the regulation of sister chromatid separation during cell division. The oncogenic potential of PTTG1 has been well characterized in the mouse, particularly mouse fibroblast (NIH3T3 cells, in which it induces cell proliferation, promotes tumor formation and angiogenesis. Human tumorigenesis is a complex and a multistep process often requiring concordant expression of a number of genes. Also due to differences between rodent and human cell biology it is difficult to extrapolate results from mouse models to humans. To determine if PTTG1 functions similarly as an oncogene in humans, we have characterized its effects on human embryonic kidney (HEK293 cells. Results We report that introduction of human PTTG1 into HEK293 cells through transfection with PTTG1 cDNA resulted in increased cell proliferation, anchorage-independent growth in soft agar, and formation of tumors after subcutaneous injection of nu/nu mice. Pathologic analysis revealed that these tumors were poorly differentiated. Both analysis of HEK293 cells transiently transfected with PTTG1 cDNA and analysis of tumors developed on injection of HEK293 cells that had been stably transfected with PTTG1 cDNA indicated significantly higher levels of secretion and expression of bFGF, VEGF and IL-8 compared to HEK293 cells transfected with pcDNA3.1 vector or uninvolved tissues collected from the mice. Mutation of the proline-rich motifs at the C-terminal of PTTG1 abolished its oncogenic properties. Mice injected with this mutated PTTG1 either did not form tumors or formed very small tumors. Taken together our results suggest that PTTG1 is a human oncogene that possesses the ability to promote tumorigenesis in human cells at least in part through the regulation of expression or secretion of bFGF, VEGF and IL-8. Conclusions Our results

  17. Autophagy induction by Bcr-Abl-expressing cells facilitates their recovery from a targeted or nontargeted treatment.

    LENUS (Irish Health Repository)

    Crowley, Lisa C

    2012-01-31

    Although Imatinib has transformed the treatment of chronic myeloid leukemia (CML), it is not curative due to the persistence of resistant cells that can regenerate the disease. We have examined how Bcr-Abl-expressing cells respond to two mechanistically different therapeutic agents, etoposide and Imatinib. We also examined Bcr-Abl expression at low and high levels as elevated expression has been associated with treatment failure. Cells expressing low levels of Bcr-Abl undergo apoptosis in response to the DNA-targeting agent (etoposide), whereas high-Bcr-Abl-expressing cells primarily induce autophagy. Autophagic populations engage a delayed nonapoptotic death; however, sufficient cells evade this and repopulate following the withdrawal of the drug. Non-Bcr-Abl-expressing 32D or Ba\\/F3 cells induce both apoptosis and autophagy in response to etoposide and can recover. Imatinib treatment induces both apoptosis and autophagy in all Bcr-Abl-expressing cells and populations rapidly recover. Inhibition of autophagy with ATG7 and Beclin1 siRNA significantly reduced the recovery of Imatinib-treated K562 cells, indicating the importance of autophagy for the recovery of treated cells. Combination regimes incorporating agents that disrupt Imatinib-induced autophagy would remain primarily targeted and may improve response to the treatment in CML.

  18. Transforming growth factor β (CiTGF-β) gene expression is induced in the inflammatory reaction of Ciona intestinalis.

    Science.gov (United States)

    Vizzini, Aiti; Di Falco, Felicia; Parrinello, Daniela; Sanfratello, Maria Antonietta; Cammarata, Matteo

    2016-02-01

    Transforming growth factor (TGF-β) is a well-known component of a regulatory cytokines superfamily that has pleiotropic functions in a broad range of cell types and is involved, in vertebrates, in numerous physiological and pathological processes. In the current study, we report on Ciona intestinalis molecular characterisation and expression of a transforming growth factor β homologue (CiTGF-β). The gene organisation, phylogenetic tree and modelling supported the close relationship with the mammalian TGF suggesting that the C. intestinalis TGF-β gene shares a common ancestor in the chordate lineages. Functionally, real-time PCR analysis showed that CiTGF-β was transcriptionally upregulated in the inflammatory process induced by LPS inoculation, suggesting that is involved in the first phase and significant in the secondary phase of the inflammatory response in which cell differentiation occurs. In situ hybridisation assays revealed that the genes transcription was upregulated in the pharynx, the main organ of the ascidian immune system, and expressed by cluster of hemocytes inside the pharynx vessels. These data supported the view that CiTGF-β is a potential molecule in immune defence systems against bacterial infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Identification of Proteins Related to Epigenetic Regulation in the Malignant Transformation of Aberrant Karyotypic Human Embryonic Stem Cells by Quantitative Proteomics

    Science.gov (United States)

    Sun, Yi; Yang, Yixuan; Zeng, Sicong; Tan, Yueqiu; Lu, Guangxiu; Lin, Ge

    2014-01-01

    Previous reports have demonstrated that human embryonic stem cells (hESCs) tend to develop genomic alterations and progress to a malignant state during long-term in vitro culture. This raises concerns of the clinical safety in using cultured hESCs. However, transformed hESCs might serve as an excellent model to determine the process of embryonic stem cell transition. In this study, ITRAQ-based tandem mass spectrometry was used to quantify normal and aberrant karyotypic hESCs proteins from simple to more complex karyotypic abnormalities. We identified and quantified 2583 proteins, and found that the expression levels of 316 proteins that represented at least 23 functional molecular groups were significantly different in both normal and abnormal hESCs. Dysregulated protein expression in epigenetic regulation was further verified in six pairs of hESC lines in early and late passage. In summary, this study is the first large-scale quantitative proteomic analysis of the malignant transformation of aberrant karyotypic hESCs. The data generated should serve as a useful reference of stem cell-derived tumor progression. Increased expression of both HDAC2 and CTNNB1 are detected as early as the pre-neoplastic stage, and might serve as prognostic markers in the malignant transformation of hESCs. PMID:24465727

  20. Transforming growth factor-beta 1 (TGF-beta1) promotes IL-2 mRNA expression through the up-regulation of NF-kappaB, AP-1 and NF-AT in EL4 cells.

    Science.gov (United States)

    Han, S H; Yea, S S; Jeon, Y J; Yang, K H; Kaminski, N E

    1998-12-01

    Transforming growth factor beta1 (TGF-beta1) has been previously shown to modulate interleukin 2 (IL-2) secretion by activated T-cells. In the present studies, we determined that TGF-beta1 induced IL-2 mRNA expression in the murine T-cell line EL4, in the absence of other stimuli. IL-2 mRNA expression was significantly induced by TGF-beta1 (0.1-1 ng/ml) over a relatively narrow concentration range, which led to the induction of IL-2 secretion. Under identical condition, we examined the effect of TGF-beta1 on the activity of nuclear factor AT (NF-AT), nuclear factor kappaB (NF-kappaB), activator protein-1 (AP-1) and octamer, all of which contribute to the regulation of IL-2 gene expression. Electrophoretic mobility shift assays showed that TGF-beta1 markedly increased NF-AT, NF-kappaB and AP-1 binding to their respective cognate DNA binding sites, whereas octamer binding remained constant, as compared with untreated cells. Employing a reporter gene expression system with p(NF-kappaB)3-CAT, p(NF-AT)3-CAT and p(AP-1)3-CAT, TGF-beta1 treatment of transfected EL4 cells induced a dose-related increase in chloramphenicol acetyltransferase activity that correlated well with the DNA binding profile found in the electrophoretic mobility shift assay studies. These results show that TGF-beta1, in the absence of any additional stimuli, up-regulates the activity of key transcription factors involved in IL-2 gene expression, including NF-AT, NF-kappaB and AP-1, to help promote IL-2 mRNA expression by EL4 cells.

  1. MMP1, MMP9, and COX2 Expressions in Promonocytes Are Induced by Breast Cancer Cells and Correlate with Collagen Degradation, Transformation-Like Morphological Changes in MCF-10A Acini, and Tumor Aggressiveness

    Directory of Open Access Journals (Sweden)

    G. K. Chimal-Ramírez

    2013-01-01

    Full Text Available Tumor-associated immune cells often lack immune effector activities, and instead they present protumoral functions. To understand how tumors promote this immunological switch, invasive and noninvasive breast cancer cell (BRC lines were cocultured with a promonocytic cell line in a Matrigel-based 3D system. We hypothesized that if communication exists between tumor and immune cells, coculturing would result in augmented expression of genes associated with tumor malignancy. Upregulation of proteases MMP1 and MMP9 and inflammatory COX2 genes was found likely in response to soluble factors. Interestingly, changes were more apparent in promonocytes and correlated with the aggressiveness of the BRC line. Increased gene expression was confirmed by collagen degradation assays and immunocytochemistry of prostaglandin 2, a product of COX2 activity. Untransformed MCF-10A cells were then used as a sensor of soluble factors with transformation-like capabilities, finding that acini formed in the presence of supernatants of the highly aggressive BRC/promonocyte cocultures often exhibited total loss of the normal architecture. These data support that tumor cells can modify immune cell gene expression and tumor aggressiveness may importantly reside in this capacity. Modeling interactions in the tumor stroma will allow the identification of genes useful as cancer prognostic markers and therapy targets.

  2. Improvement of soybean transformation via Agrobacterium tumefaciens methods involving α-aminooxyacetic acid and sonication treatments enlightened by gene expression profile analysis.

    Science.gov (United States)

    Zhang, Yan-Min; Liu, Zi-Hui; Yang, Rui-Juan; Li, Guo-Liang; Guo, Xiu-Lin; Zhang, Hua-Ning; Zhang, Hong-Mei; Di, Rui; Zhao, Qing-Song; Zhang, Meng-Chen

    2016-06-01

    Antagonists and sonication treatment relieved the structural barriers of Agrobacterium entering into cells; hindered signal perception and transmission; alleviated defense responses and increased cell susceptibility to Agrobacterium infection. Soybean gene expression analysis was performed to elucidate the general response of soybean plant to Agrobacterium at an early stage of infection. Agrobacterium infection stimulated the PAMPs-triggered immunity (BRI1, BAK1, BZR1, FLS2 and EFR) and effector-triggered immunity (RPM1, RPS2, RPS5, RIN4, and PBS1); up-regulated the transcript factors (WRKY25, WRKY29, MEKK1P, MKK4/5P and MYC2) in MAPK pathway; strengthened the biosynthesis of flavonoid and isoflavonoid in the second metabolism; finally led to a fierce defense response of soybean to Agrobacterium infection and thereby lower transformation efficiency. To overcome it, antagonist α-aminooxyacetic acid (AOA) and sonication treatment along with Agrobacterium infection were applied. This novel method dramatically decreased the expression of genes coding for F3'H, HCT, β-glucosidase and IF7GT, etc., which are important for isoflavone biosynthesis or the interconversion of aglycones and glycon; genes coding for peroxidase, FLS2, PBS1 and transcription factor MYC2, etc., which are important components in plant-pathogen interaction; and genes coding for GPAT and α-L-fucosidase, which are important in polyesters formation in cell membrane and the degradation of fucose-containing glycoproteins and glycolipids on the external surface of cell membrane, respectively. This analysis implied that AOA and sonication treatment not only relieved the structural membrane barriers of Agrobacterium entering into cells, but also hindered the perception of 'invasion' signal on cell membrane and intercellular signal transmission, thus effectively alleviated the defense responses and increased the cell susceptibility to Agrobacterium infection. All these factors benefit the transformation

  3. Inhibition and reversal of nickel-induced transformation by the histone deacetylase inhibitor trichostatin A

    International Nuclear Information System (INIS)

    Zhang Qunwei; Salnikow, Konstantin; Kluz, Thomas; Chen, L.C.; Su, W.C.; Costa, Max

    2003-01-01

    The carcinogenic process initiated by nongenotoxic carcinogens involves modulation of gene expression. Nickel compounds have low mutagenic activity, but are highly carcinogenic. In vitro both mouse and human cells can be efficiently transformed by soluble and insoluble nickel compounds to anchorage-independent growth. Because previous studies have shown that carcinogenic nickel compounds silence genes by inhibiting histone acetylation and enhancing DNA methylation, we investigated the effect of enhancing histone acetylation on cell transformation. The exposure of nickel-transformed cells to the histone deacetylase inhibitor trichostatin A (TSA) resulted in the appearance of significant number of revertants measured by their inability to grow in soft agar. Using the Affymetrix GeneChip we found that the level of expression of a significant number of genes was changed (suppressed or upregulated) in nickel-transformed clones but returned to a normal level in revertants obtained following TSA treatment. Moreover, we found that treatment of cells with TSA inhibited the ability of nickel to transform mouse PW cells to anchorage-independent growth. Treatment with TSA also inhibited the ability of nickel to transform human HOS cells, although to a lesser extent. In contrast, treatment with TSA was not able to revert established cancer cell lines as readily as the nickel-transformed cells. These data indicated that modulation of gene expression is important for nickel-induced transformation

  4. Lead facilitates foci formation in a Balb/c-3T3 two-step cell transformation model: role of Ape1 function.

    Science.gov (United States)

    Hernández-Franco, Pablo; Silva, Martín; Franco, Rodrigo; Valverde, Mahara; Rojas, Emilio

    2018-04-01

    Several possible mechanisms have been examined to gain an understanding on the carcinogenic properties of lead, which include among others, mitogenesis, alteration of gene expression, oxidative damage, and inhibition of DNA repair. The aim of the present study was to explore if low concentrations of lead, relevant for human exposure, interfere with Ape1 function, a base excision repair enzyme, and its role in cell transformation in Balb/c-3T3. Lead acetate 5 and 30 μM induced APE1 mRNA and upregulation of protein expression. This increase in mRNA expression is consistent throughout the chronic exposure. Additionally, we also found an impaired function of Ape1 through molecular beacon-based assay. To evaluate the impact of lead on foci formation, a Balb/c-3T3 two-step transformation model was used. Balb/c-3T3 cells were pretreated 1 week with low concentrations of lead before induction of transformation with n-methyl-n-nitrosoguanidine (MNNG) (0.5 μg/mL) and 12-O-tetradecanoylphorbol-13-acetate (TPA) (0.1 μg/mL) (a classical two-step protocol). Morphological cell transformation increased in response to lead pretreatment that was paralleled with an increase in Ape1 mRNA and protein overexpression and an impairment of Ape1 activity and correlating with foci number. In addition, we found that lead pretreatment and MNNG (transformation initiator) increased DNA damage, determined by comet assay. Our data suggest that low lead concentrations (5, 30 μM) could play a facilitating role in cellular transformation, probably through the impaired function of housekeeping genes such as Ape1, leading to DNA damage accumulation and chromosomal instability, one of the most important hallmarks of cancer induced by chronic exposures.

  5. Expression of a TGF-{beta} regulated cyclin-dependent kinase inhibitor in normal and immortalized airway epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, L.A.; Bloomfield, C.; Johnson, N.F. [and others

    1995-12-01

    Tumors arising from epithelial cells, including lung cancers are frequently resistant to factors that regulate growth and differentiation in normal in normal cells. Once such factor is transforming growth factor-{Beta} (TGF-{Beta}). Escape from the growth-inhibitory effects of TGF-{Beta} is thought to be a key step in the transformation of airway epithelial cells. most lung cancer cell lines require serum for growth. In contrast, normal human bronchial epithelial (NHBE) cells are exquisitely sensitive to growth-inhibitory and differentiating effects of TGF-{Beta}. The recent identification of a novel cyclin-dependent kinase inhibitor, p15{sup INK4B}, which is regulated by TGF-{Beta}, suggests a mechanism by which TGF-{Beta} mediates growth arrest in NHBE cells. The purpose of this study was two-fold: (1) to determine if p15{sup INK4B} is induced by TGF-{Beta} in NHBE cells or immortalized bronchial epithelial (R.1) cells and if that induction corresponds to a G1/S cell-cycle arrest; (2) to determine the temporal relationship between p15{sup INK4B} induction, cell-cycle arrest, and the phosphorylation state of the pRB because it is thought that p15{sup INK4B} acts indirectly by preventing phosphorylation of the RB gene product. In this study, expression of p15{sup INK4B} was examined in NHBE cells and R.1 cells at different time intervals following TGF-{Beta} treatment. The expression of this kinase inhibitor and its relationship to the cell and the pRb phosphorylation state were examined in cells that were both sensitive (NHBE) and resistant (R.1) to the effects of TGF-{Beta}. These results suggest that the cyclin-dependent kinase inhibitor, p15{sup INK4B}, is involved in airway epithelial cell differentiation and that loss or reduction of expression plays a role in the resistance of transformed or neoplastic cells to the growth-inhibitory effects of TGF-{Beta}.

  6. Growth suppression by transforming growth factor beta 1 of human small-cell lung cancer cell lines is associated with expression of the type II receptor

    DEFF Research Database (Denmark)

    Nørgaard, P; Damstrup, L; Rygaard, K

    1994-01-01

    was observed in two cell lines expressing only type III receptor and in TGF-beta-r negative cell lines. In two cell lines expressing all three receptor types, growth suppression was accompanied by morphological changes. To evaluate the possible involvement of the retinoblastoma protein (pRb) in mediating...

  7. Foxp3-dependent transformation of human primary CD4+ T lymphocytes by the retroviral protein tax.

    Science.gov (United States)

    Chen, Li; Liu, Dan; Zhang, Yang; Zhang, Huan; Cheng, Hua

    2015-10-23

    The retroviral Tax proteins of human T cell leukemia virus type 1 and 2 (HTLV-1 and -2) are highly homologous viral transactivators. Both viral proteins can immortalize human primary CD4+ memory T cells, but when expressed alone they rarely transform T cells. In the present study, we found that the Tax proteins displayed a differential ability to immortalize human CD4+Foxp3+ T cells with characteristic expression of CTLA-4 and GITR. Because epidermal growth factor receptor (EGFR) was reportedly expressed and activated in a subset of CD4+Foxp3+ T cells, we introduced an activated EGFR into Tax-immortalized CD4+Foxp3+ T cells. We observed that these modified cells were grown independently of exogenous IL-2, correlating with a T cell transformation phenotype. In Tax-immortalized CD4+Foxp3- T cells, ectopic expression of Foxp3 was a prerequisite for Tax transformation of T cells. Accordingly, treatment of the transformed T cells with erlotinib, a selective inhibitor of EGFR, induced degradation of EGFR in lysosome, consequently causing T cell growth inhibition. Further, we identified autophagy as a crucial cellular survival pathway for the transformed T cells. Silencing key autophagy molecules including Beclin1, Atg5 and PI3 kinase class III (PI3KC3) resulted in drastic impairment of T cell growth. Our data, therefore, unveiled a previously unidentified role of Foxp3 in T cell transformation, providing a molecular basis for HTLV-1 transformation of CD4+Foxp3+ T cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. The c-Jun N-terminal kinase pathway is critical for cell transformation by the latent membrane protein 1 of Epstein-Barr virus

    International Nuclear Information System (INIS)

    Kutz, Helmut; Reisbach, Gilbert; Schultheiss, Ute; Kieser, Arnd

    2008-01-01

    The latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) transforms cells activating signal transduction pathways such as NF-κB, PI3-kinase, or c-Jun N-terminal kinase (JNK). Here, we investigated the functional role of the LMP1-induced JNK pathway in cell transformation. Expression of a novel dominant-negative JNK1 allele caused a block of proliferation in LMP1-transformed Rat1 fibroblasts. The JNK-specific inhibitor SP600125 reproduced this effect in Rat1-LMP1 cells and efficiently interfered with proliferation of EBV-transformed lymphoblastoid cells (LCLs). Inhibition of the LMP1-induced JNK pathway in LCLs caused the downregulation of c-Jun and Cdc2, the essential G2/M cell cycle kinase, which was accompanied by a cell cycle arrest of LCLs at G2/M phase transition. Moreover, SP600125 retarded tumor growth of LCLs in a xenograft model in SCID mice. Our data support a critical role of the LMP1-induced JNK pathway for proliferation of LMP1-transformed cells and characterize JNK as a potential target for intervention against EBV-induced malignancies

  9. Leukaemia virus infection promotes fibroblast transformation by normal BALB/c mouse DNA

    NARCIS (Netherlands)

    Krump-Konvalinkova, V.; Berg, K.J. van den

    1980-01-01

    All normal cells are thought to carry genetic information for oncogenic transformation, which, on activation to continuous expression. might make the cell cancerous. The presently known transforming retroviruses contain transforming genes which were probably derived by recombination of a slow

  10. NKp46 identifies an NKT cell subset susceptible to leukemic transformation in mouse and human

    Science.gov (United States)

    Yu, Jianhua; Mitsui, Takeki; Wei, Min; Mao, Hsiaoyin; Butchar, Jonathan P.; Shah, Mithun Vinod; Zhang, Jianying; Mishra, Anjali; Alvarez-Breckenridge, Christopher; Liu, Xingluo; Liu, Shujun; Yokohama, Akihiko; Trotta, Rossana; Marcucci, Guido; Benson, Don M.; Loughran, Thomas P.; Tridandapani, Susheela; Caligiuri, Michael A.

    2011-01-01

    IL-15 may have a role in the development of T cell large granular lymphocyte (T-LGL) or NKT leukemias. However, the mechanisms of action and the identity of the cell subset that undergoes leukemic transformation remain elusive. Here we show that in both mice and humans, NKp46 expression marks a minute population of WT NKT cells with higher activity and potency to become leukemic. Virtually 100% of T-LGL leukemias in IL-15 transgenic mice expressed NKp46, as did a majority of human T-LGL leukemias. The minute NKp46+ NKT population, but not the NKp46– NKT population, was selectively expanded by overexpression of endogenous IL-15. Importantly, IL-15 transgenic NKp46– NKT cells did not become NKp46+ in vivo, suggesting that NKp46+ T-LGL leukemia cells were the malignant counterpart of the minute WT NKp46+ NKT population. Mechanistically, NKp46+ NKT cells possessed higher responsiveness to IL-15 in vitro and in vivo compared with that of their NKp46– NKT counterparts. Furthermore, interruption of IL-15 signaling using a neutralizing antibody could prevent LGL leukemia in IL-15 transgenic mice. Collectively, our data demonstrate that NKp46 identifies a functionally distinct NKT subset in mice and humans that appears to be directly susceptible to leukemic transformation when IL-15 is overexpressed. Thus, IL-15 signaling and NKp46 may be useful targets in the treatment of patients with T-LGL or NKT leukemia. PMID:21364281

  11. Establishment and characterization of equine fibroblast cell lines transformed in vivo and in vitro by BPV-1: Model systems for equine sarcoids

    International Nuclear Information System (INIS)

    Yuan, Z.Q.; Gault, E.A.; Gobeil, P.; Nixon, C.; Campo, M.S.; Nasir, L.

    2008-01-01

    It is now widely recognized that BPV-1 and less commonly BPV-2 are the causative agents of equine sarcoids. Here we present the generation of equine cell lines harboring BPV-1 genomes and expressing viral genes. These lines have been either explanted from sarcoid biopsies or generated in vitro by transfection of primary fibroblasts with BPV-1 DNA. Previously detected BPV-1 genome variations in equine sarcoids are also found in sarcoid cell lines, and only variant BPV-1 genomes can transform equine cells. These equine cell lines are morphologically transformed, proliferate faster than parental cells, have an extended life span and can grow independently of substrate. These characteristics are more marked the higher the level of viral E5, E6 and E7 gene expression. These findings confirm that the virus has an active role in the induction of sarcoids and the lines will be invaluable for further studies on the role of BPV-1 in sarcoid pathology

  12. Plant Cell Division Analyzed by Transient Agrobacterium-Mediated Transformation of Tobacco BY-2 Cells.

    Science.gov (United States)

    Buschmann, Henrik

    2016-01-01

    The continuing analysis of plant cell division will require additional protein localization studies. This is greatly aided by GFP-technology, but plant transformation and the maintenance of transgenic lines can present a significant technical bottleneck. In this chapter I describe a method for the Agrobacterium-mediated genetic transformation of tobacco BY-2 cells. The method allows for the microscopic analysis of fluorescence-tagged proteins in dividing cells in within 2 days after starting a coculture. This transient transformation procedure requires only standard laboratory equipment. It is hoped that this rapid method would aid researchers conducting live-cell localization studies in plant mitosis and cytokinesis.

  13. Clinical-grade production of human mesenchymal stromal cells: occurrence of aneuploidy without transformation.

    Science.gov (United States)

    Tarte, Karin; Gaillard, Julien; Lataillade, Jean-Jacques; Fouillard, Loic; Becker, Martine; Mossafa, Hossein; Tchirkov, Andrei; Rouard, Hélène; Henry, Catherine; Splingard, Marie; Dulong, Joelle; Monnier, Delphine; Gourmelon, Patrick; Gorin, Norbert-Claude; Sensebé, Luc

    2010-02-25

    Clinical-grade human mesenchymal stromal cells (MSCs) have been expanded in vitro for tissue engineering or immunoregulatory purposes without standardized culture conditions or release criteria. Although human MSCs show poor susceptibility for oncogenic transformation, 2 recent studies described their capacity to accumulate chromosomal instability and to give rise to carcinoma in immunocompromised mice after long-term culture. We thus investigated the immunologic and genetic features of MSCs expanded with fetal calf serum and fibroblast growth factor or with platelet lysate in 4 cell-therapy facilities during 2 multicenter clinical trials. Cultured MSCs showed a moderate expression of human leukocyte antigen-DR without alteration of their low immunogenicity or their immunomodulatory capacity. Moreover, some transient and donor-dependent recurring aneuploidy was detected in vitro, independently of the culture process. However, MSCs with or without chromosomal alterations showed progressive growth arrest and entered senescence without evidence of transformation either in vitro or in vivo.

  14. High-Throughput Agrobacterium-mediated Transformation of Medicago Truncatula in Comparison to Two Expression Vectors

    International Nuclear Information System (INIS)

    Sultana, T.; Deeba, F.; Naqvi, S. M. S.

    2016-01-01

    Legumes have been turbulent to efficient Agrobacterium-mediated transformation for a long time. The selection of Medicago truncatula as a model legume plant for molecular analysis resulted in the development of efficient Agrobacterium-mediated transformation protocols. In current study, M. truncatula transformed plants expressing OsRGLP1 were obtained through GATEWAY technology using pGOsRGLP1 (pH7WG2.0=OsRGLP1). The transformation efficiency of this vector was compared with expression vector from pCAMBIA series over-expressing same gene (pCOsRGLP1). A lower number of explants generated hygromycin resistant plantlet for instance, 18.3 with pGOsRGLP1 vector as compared to 35.5 percent with pCOsRGLP1 vector. Transformation efficiency of PCR positive plants generated was 9.4 percent for pGOsRGLP1 while 21.6 percent for pCOsRGLP1. Furthermore 24.4 percent of explants generated antibiotic resistant plantlet on 20 mgl/sup -1/ of hygromycin which was higher than on 15 mgl/sup -1/ of hygromycin such as 12.2 percent. T/sub 1/ progeny analysis indicated that the transgene was inherited in Mendelian manner. The functionally active status of transgene was monitored by high level of Superoxide dismutase (SOD) activity in transformed progeny. (author)

  15. Depleted uranium induces neoplastic transformation in human lung epithelial cells.

    Science.gov (United States)

    Xie, Hong; LaCerte, Carolyne; Thompson, W Douglas; Wise, John Pierce

    2010-02-15

    Depleted uranium (DU) is commonly used in military armor and munitions, and thus, exposure of soldiers and noncombatants is frequent and widespread. Previous studies have shown that DU has both chemical and radiological toxicity and that the primary route of exposure of DU to humans is through inhalation and ingestion. However, there is limited research information on the potential carcinogenicity of DU in human bronchial cells. Accordingly, we determined the neoplastic transforming ability of particulate DU to human bronchial epithelial cells (BEP2D). We observed the loss of contact inhibition and anchorage independent growth in cells exposed to DU after 24 h. We also characterized these DU-induced transformed cell lines and found that 40% of the cell lines exhibit alterations in plating efficiency and no significant changes in the cytotoxic response to DU. Cytogenetic analyses showed that 53% of the DU-transformed cell lines possess a hypodiploid phenotype. These data indicate that human bronchial cells are transformed by DU and exhibit significant chromosome instability consistent with a neoplastic phenotype.

  16. The cell cycle regulator ecdysoneless cooperates with H-Ras to promote oncogenic transformation of human mammary epithelial cells.

    Science.gov (United States)

    Bele, Aditya; Mirza, Sameer; Zhang, Ying; Ahmad Mir, Riyaz; Lin, Simon; Kim, Jun Hyun; Gurumurthy, Channabasavaiah Basavaraju; West, William; Qiu, Fang; Band, Hamid; Band, Vimla

    2015-01-01

    The mammalian ortholog of Drosophila ecdysoneless (Ecd) gene product regulates Rb-E2F interaction and is required for cell cycle progression. Ecd is overexpressed in breast cancer and its overexpression predicts shorter survival in patients with ErbB2-positive tumors. Here, we demonstrate Ecd knock down (KD) in human mammary epithelial cells (hMECs) induces growth arrest, similar to the impact of Ecd Knock out (KO) in mouse embryonic fibroblasts. Furthermore, whole-genome mRNA expression analysis of control vs. Ecd KD in hMECs demonstrated that several of the top 40 genes that were down-regulated were E2F target genes. To address the role of Ecd in mammary oncogenesis, we overexpressed Ecd and/or mutant H-Ras in hTERT-immortalized hMECs. Cell cycle analyses revealed hMECs overexpressing Ecd+Ras showed incomplete arrest in G1 phase upon growth factor deprivation, and more rapid cell cycle progression in growth factor-containing medium. Analyses of cell migration, invasion, acinar structures in 3-D Matrigel and anchorage-independent growth demonstrated that Ecd+Ras-overexpressing cells exhibit substantially more dramatic transformed phenotype as compared to cells expressing vector, Ras or Ecd. Under conditions of nutrient deprivation, Ecd+Ras-overexpressing hMECs exhibited better survival, with substantial upregulation of the autophagy marker LC3 both at the mRNA and protein levels. Significantly, while hMECs expressing Ecd or mutant Ras alone did not form tumors in NOD/SCID mice, Ecd+Ras-overexpressing hMECs formed tumors, clearly demonstrating oncogenic cooperation between Ecd and mutant Ras. Collectively, we demonstrate an important co-oncogenic role of Ecd in the progression of mammary oncogenesis through promoting cell survival.

  17. Obesity Suppresses Cell-Competition-Mediated Apical Elimination of RasV12-Transformed Cells from Epithelial Tissues.

    Science.gov (United States)

    Sasaki, Ayana; Nagatake, Takahiro; Egami, Riku; Gu, Guoqiang; Takigawa, Ichigaku; Ikeda, Wataru; Nakatani, Tomoya; Kunisawa, Jun; Fujita, Yasuyuki

    2018-04-24

    Recent studies have revealed that newly emerging transformed cells are often eliminated from epithelial tissues via cell competition with the surrounding normal epithelial cells. This cancer preventive phenomenon is termed epithelial defense against cancer (EDAC). However, it remains largely unknown whether and how EDAC is diminished during carcinogenesis. In this study, using a cell competition mouse model, we show that high-fat diet (HFD) feeding substantially attenuates the frequency of apical elimination of RasV12-transformed cells from intestinal and pancreatic epithelia. This process involves both lipid metabolism and chronic inflammation. Furthermore, aspirin treatment significantly facilitates eradication of transformed cells from the epithelial tissues in HFD-fed mice. Thus, our work demonstrates that obesity can profoundly influence competitive interaction between normal and transformed cells, providing insights into cell competition and cancer preventive medicine. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  18. Despite differential gene expression profiles pediatric MDS derived mesenchymal stromal cells display functionality in vitro.

    Science.gov (United States)

    Calkoen, F G J; Vervat, C; van Pel, M; de Haas, V; Vijfhuizen, L S; Eising, E; Kroes, W G M; 't Hoen, P A C; van den Heuvel-Eibrink, M M; Egeler, R M; van Tol, M J D; Ball, L M

    2015-03-01

    Pediatric myelodysplastic syndrome (MDS) is a heterogeneous disease covering a spectrum ranging from aplasia (RCC) to myeloproliferation (RAEB(t)). In adult-type MDS there is increasing evidence for abnormal function of the bone-marrow microenvironment. Here, we extensively studied the mesenchymal stromal cells (MSCs) derived from children with MDS. MSCs were expanded from the bone-marrow of 17 MDS patients (RCC: n=10 and advanced MDS: n=7) and pediatric controls (n=10). No differences were observed with respect to phenotype, differentiation capacity, immunomodulatory capacity or hematopoietic support. mRNA expression analysis by Deep-SAGE revealed increased IL-6 expression in RCC- and RAEB(t)-MDS. RCC-MDS MSC expressed increased levels of DKK3, a protein associated with decreased apoptosis. RAEB(t)-MDS revealed increased CRLF1 and decreased DAPK1 expressions. This pattern has been associated with transformation in hematopoietic malignancies. Genes reported to be differentially expressed in adult MDS-MSC did not differ between MSC of pediatric MDS and controls. An altered mRNA expression profile, associated with cell survival and malignant transformation, of MSC derived from children with MDS strengthens the hypothesis that the micro-environment is of importance in this disease. Our data support the understanding that pediatric and adult MDS are two different diseases. Further evaluation of the pathways involved might reveal additional therapy targets. Copyright © 2015. Published by Elsevier B.V.

  19. Membrane associated ion transport enzymes in normal and transformed fibroblasts and epithelial cells

    International Nuclear Information System (INIS)

    Borek, C.

    1982-01-01

    In an effort to evaluate membrane changes associated with neoplastic transformation of fibroblasts and epithelial cells by radiation and chemicals, alterations in membrane-associated (Na + + K + )-ATPase and 5'-nucleotidase activities were investigated. Cell cultures consisted of normal and radiation transformed hamster embryo fibroblasts (HE) and mouse C3H 10T 1/2 fibroblasts, normal and chemically transformed adult rat liver epithelial cells (ARL), as well as hepatocarcinoma cells induced by the liver transformants. Transformed fibroblasts demonstrated a 1-2 fold increase in (Na + + K + )-ATPase activity over the normal, while the transformed liver epithelial cells and carcinoma cells showed a 60% and 40% decrease in activity compared to the normal values, respectively. The 5'-nucleotidase activity was 2 to 3 times higher in the transformed fibroblasts

  20. Synergistic Induction of Cyclooxygenase-2 by Transforming Growth Factor-β1 and Epidermal Growth Factor Inhibits Apoptosis in Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Debabrata Saha

    1999-12-01

    Full Text Available Increased expression of cyclooxygenase-2 (COX-2 expression has been observed in several human tumor types and in selected animal and cell culture models of carcinogenesis, including lung cancer. Increased expression of COX-2 and production of prostaglandins appear to provide a survival advantage to transformed cells through the inhibition of apoptosis, increased attachment to extracellular matrix, increased invasiveness, the stimulation of angiogenesis. In the present studies, we found that transforming growth factor β1 (TGF-β1 and epidermal growth factor (EGF synergistically induced the expression of COX-2 and prostaglandin E2 (PGE2 production in mink lung epithelial (Mvi Lu cells. EGF, but not PDGF or IGF-1, was able to inhibit TGF-β1-induced apoptosis in Mvi Lu cells and this effect was blocked by NS-398, a selective inhibitor of COX-2 activity, suggesting a possible role for COX-2 in the anti-apoptosic effect of EGF receptor ligands. The combination of TGF-β1 and EGF also significantly induced COX-2 expression in rat intestinal epithelial (RIE-1 cells and completely prevented sodium butyrate (NaBu-induced apoptosis. The synergistic induction of COX-2 by TGF-β1 and EGF was not observed in R1B-L17 cells, a line derived from Mvi Lu cells that lacks the TGF-β type-I receptor. AG1478, a selective inhibitor of EGF receptor tyrosine kinase activity, completely suppressed the induction of COX-2 expression by either EGF or TGF-β1+EGF. Also, PD98059, a specific inhibitor of MEK/ERK pathway, SB203580, a specific inhibitor of p38 MAPK activity, significantly inhibited the induction of COX-2 in response to combined EGF and TGF-β1. These results suggest an important collaborative interaction of TGF-β1 and EGF signaling in the induction of COX-2 and prostaglandin production in Mv1Lu cells.

  1. Activated human mast cells induce LOX-1-specific scavenger receptor expression in human monocyte-derived macrophages.

    Directory of Open Access Journals (Sweden)

    Mervi Alanne-Kinnunen

    Full Text Available Activated mast cells in atherosclerotic lesions degranulate and release bioactive compounds capable of regulating atherogenesis. Here we examined the ability of activated human primary mast cells to regulate the expression of the major scavenger receptors in cultured human primary monocyte-derived macrophages (HMDMs.Components released by immunologically activated human primary mast cells induced a transient expression of lectin-like oxidized LDL receptor (LOX-1 mRNA in HMDMs, while the expression of two other scavenger receptors, MSR1 and CD36, remained unaffected. The LOX-1-inducing secretory components were identified as histamine, tumor necrosis factor alpha (TNF-α, and transforming growth factor beta (TGF-β1, which exhibited a synergistic effect on LOX-1 mRNA expression. Histamine induced a transient expression of LOX-1 protein. Mast cell -induced increase in LOX-1 expression was not associated with increased uptake of oxidized LDL by the macrophages.Mast cell-derived histamine, TNF-α, and TGF-β1 act in concert to induce a transient increase in LOX-1 expression in human primary monocyte-derived macrophages. The LOX-1-inducing activity potentially endows mast cells a hitherto unrecognized role in the regulation of innate immune reactions in atherogenesis.

  2. Molecular pathways of early CD105-positive erythroid cells as compared with CD34-positive common precursor cells by flow cytometric cell-sorting and gene expression profiling

    International Nuclear Information System (INIS)

    Machherndl-Spandl, S; Suessner, S; Danzer, M; Proell, J; Gabriel, C; Lauf, J; Sylie, R; Klein, H-U; Béné, M C; Weltermann, A; Bettelheim, P

    2013-01-01

    Special attention has recently been drawn to the molecular network of different genes that are responsible for the development of erythroid cells. The aim of the present study was to establish in detail the immunophenotype of early erythroid cells and to compare the gene expression profile of freshly isolated early erythroid precursors with that of the CD34-positive (CD34 + ) compartment. Multiparameter flow cytometric analyses of human bone marrow mononuclear cell fractions (n=20) defined three distinct early erythroid stages. The gene expression profile of sorted early erythroid cells was analyzed by Affymetrix array technology. For 4524 genes, a differential regulation was found in CD105-positive erythroid cells as compared with the CD34 + progenitor compartment (2362 upregulated genes). A highly significant difference was observed in the expression level of genes involved in transcription, heme synthesis, iron and mitochondrial metabolism and transforming growth factor-β signaling. A comparison with recently published data showed over 1000 genes that as yet have not been reported to be upregulated in the early erythroid lineage. The gene expression level within distinct pathways could be illustrated directly by applying the Ingenuity software program. The results of gene expression analyses can be seen at the Gene Expression Omnibus repository

  3. Developmental expression and differentiation-related neuron-specific splicing of metastasis suppressor 1 (Mtss1 in normal and transformed cerebellar cells

    Directory of Open Access Journals (Sweden)

    Baader Stephan L

    2007-10-01

    Full Text Available Abstract Background Mtss1 encodes an actin-binding protein, dysregulated in a variety of tumors, that interacts with sonic hedgehog/Gli signaling in epidermal cells. Given the prime importance of this pathway for cerebellar development and tumorigenesis, we assessed expression of Mtss1 in the developing murine cerebellum and human medulloblastoma specimens. Results During development, Mtss1 is transiently expressed in granule cells, from the time point they cease to proliferate to their synaptic integration. It is also expressed by granule cell precursor-derived medulloblastomas. In the adult CNS, Mtss1 is found exclusively in cerebellar Purkinje cells. Neuronal differentiation is accompanied by a switch in Mtss1 splicing. Whereas immature granule cells express a Mtss1 variant observed also in peripheral tissues and comprising exon 12, this exon is replaced by a CNS-specific exon, 12a, in more mature granule cells and in adult Purkinje cells. Bioinformatic analysis of Mtss1 suggests that differential exon usage may affect interaction with Fyn and Src, two tyrosine kinases previously recognized as critical for cerebellar cell migration and histogenesis. Further, this approach led to the identification of two evolutionary conserved nuclear localization sequences. These overlap with the actin filament binding site of Mtss1, and one also harbors a potential PKA and PKC phosphorylation site. Conclusion Both the pattern of expression and splicing of Mtss1 is developmentally regulated in the murine cerebellum. These findings are discussed with a view on the potential role of Mtss1 for cytoskeletal dynamics in developing and mature cerebellar neurons.

  4. The hemostatic agent ethamsylate enhances P-selectin membrane expression in human platelets and cultured endothelial cells.

    Science.gov (United States)

    Alvarez-Guerra, Miriam; Hernandez, Maria Rosa; Escolar, Ginés; Chiavaroli, Carlo; Garay, Ricardo P; Hannaert, Patrick

    2002-09-15

    Ethamsylate possesses antihemorrhagic properties, but whether or not it directly activates blood platelets is unclear. Here we investigated the platelet activation potential of ethamsylate, by measuring membrane P-selectin expression with flow cytometry in human whole blood and also by immunofluorescence imaging of isolated human platelets. Moreover, we measured membrane P-selectin expression in the SV40-transformed aortic rat endothelial cell line (SVAREC) and 14C-ethamsylate membrane binding and/or uptake in platelets and endothelial cells. Whole blood flow cytometry showed a modest, but statistically significant increase by ethamsylate in the percentage of platelets expressing P-selectin (from 2% to 4-5%, p ethamsylate tested (1 microM), with maximal enhancement of P-selectin expression (75-90%) at 10 microM ethamsylate. Similar results were obtained in SVAREC endothelial cells. 14C-ethamsylate specifically bound to platelets and endothelial cell membranes, without significant uptake into the cell interior. In conclusion, ethamsylate enhances membrane P-selectin expression in human platelets and in cultured endothelial cells. Ethamsylate specifically binds to some protein receptor in platelet and endothelial cell membranes, receptor which can signal for membrane P-selectin expression. These results support the view that ethamsylate acts on the first step of hemostasis, by improving platelet adhesiveness and restoring capillary resistance. Copyright 2002 Elsevier Science Ltd.

  5. Induction of malignant transformation in CHL-1 cells by exposure to tritiated water

    International Nuclear Information System (INIS)

    Zou Shu'ai; Wang Hui

    1992-01-01

    The induction of neoplastic transformation in CHL-1 cells by low-dose-rate exposure to tritiated water was reported. CHL-1 cells were exposed to tritiated water (9.25 x 10 5 - 3.7 x 10 6 Bq/mL) for 24-96 hours and the accumulated doses were estimated to be 0.055-0.88 Gy, respectively. Neoplastic transformation was found in all exposed cell groups. The morphological study and transplantation test was carried out for demonstration malignancy of the transformed cells and the results show that they are with the morphology and behaviour for malignant tumour cells. For CHL-1 cells exposed to various doses of tritiated water, transformation rates were found to be from 3.28% to 13.0% at dose of 0.055-0.88 Gy. In order to estimate RBE of tritium for malignant transformation in CHL-1 cells, the induction of malignant transformation in CHL-1 cells by exposure to 137 Cs gamma-rays was carried out at dose rates of 0.359 Gy/24 hr and transformation rates for irradiated CHL-1 cells were found to be from 2.59% to 13.4%. Based on these data, RBE of tritium for malignant transformation in CHL-1 cells was estimated to be 1.6

  6. Caffeine toxicity is inversely related to DNA repair in simian virus 40-transformed xeroderma pigmentosum cells irradiated with ultraviolet light

    International Nuclear Information System (INIS)

    Cleaver, J.E.

    1989-01-01

    Human cells transformed by simian virus 40 (SV40) are more sensitive to killing by ultraviolet light when grown in caffeine after irradiation. The degree of sensitization at 2 mM caffeine (expressed as the ratio of the 37% survival dose for control cells divided by the 37% survival dose for cells grown in caffeine, i.e., the dose modification factor) was approximately 1.9 in transformed normal cells and 3.8-5.8 in excision-defective xeroderma pigmentosum (XP) groups A, C, and D cells. A large dose modification factor of 12 was observed in a transformed XP variant cell line. Chinese hamster ovary cells were not significantly different from transformed normal human cells, with a maximum dose modification factor of 1.5. Two radioresistant XP revertants that do not excise cyclobutane dimers gave different responses; one resembled its group A parent in being sensitized by caffeine, and one did not. These results can be interpreted on the basis of a single hypothesis that cells are killed as a result of attempts to replicate damaged DNA. Increased replication rates caused by transformation, increased numbers of replication forks in DNA caused by caffeine, and increased numbers of damaged sites ahead of replication forks in excision-defective cells are all processes that will consequently increase killing according to this hypothesis. A corollary is that the XP variant may be highly sensitized to caffeine because of excision defects at the DNA replication forks, an idea that may be important in designing cloning strategies for the XP variant gene

  7. Caffeine toxicity is inversely related to DNA repair in simian virus 40-transformed xeroderma pigmentosum cells irradiated with ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Cleaver, J.E. (Univ. of California, San Francisco (USA))

    1989-01-01

    Human cells transformed by simian virus 40 (SV40) are more sensitive to killing by ultraviolet light when grown in caffeine after irradiation. The degree of sensitization at 2 mM caffeine (expressed as the ratio of the 37% survival dose for control cells divided by the 37% survival dose for cells grown in caffeine, i.e., the dose modification factor) was approximately 1.9 in transformed normal cells and 3.8-5.8 in excision-defective xeroderma pigmentosum (XP) groups A, C, and D cells. A large dose modification factor of 12 was observed in a transformed XP variant cell line. Chinese hamster ovary cells were not significantly different from transformed normal human cells, with a maximum dose modification factor of 1.5. Two radioresistant XP revertants that do not excise cyclobutane dimers gave different responses; one resembled its group A parent in being sensitized by caffeine, and one did not. These results can be interpreted on the basis of a single hypothesis that cells are killed as a result of attempts to replicate damaged DNA. Increased replication rates caused by transformation, increased numbers of replication forks in DNA caused by caffeine, and increased numbers of damaged sites ahead of replication forks in excision-defective cells are all processes that will consequently increase killing according to this hypothesis. A corollary is that the XP variant may be highly sensitized to caffeine because of excision defects at the DNA replication forks, an idea that may be important in designing cloning strategies for the XP variant gene.

  8. SWAP-70 contributes to spontaneous transformation of mouse embryo fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yu-Tzu; Shu, Chung-Li; Lai, Jing-Yang; Lin, Ching-Yu; Chuu, Chih-Pin [Institute of Cellular and System Medicine National Health Research Institute, Zhunan Town 35053, Miaoli County, Taiwan, ROC (China); Morishita, Kazuhiro; Ichikawa, Tomonaga [Division of Tumor and Cellular Biochemistry Department of Medical Sciences Faculty of Medicine University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki-shi, Miyazaki 889-1692 Japan (Japan); Jessberger, Rolf [Faculty of Medicine Carl Gustav Carus, Institute of Physiological Chemistry, Dresden University of Technology, Dresden (Germany); Fukui, Yasuhisa, E-mail: 990412@nhri.org.tw [Institute of Cellular and System Medicine National Health Research Institute, Zhunan Town 35053, Miaoli County, Taiwan, ROC (China)

    2016-07-15

    Mouse embryo fibroblasts (MEFs) grow slowly after cultivation from animals, however, after an extended period of cultivation, their growth accelerates. We found that SWAP-70 deficient MEFs failed to increase growth rates. They maintain normal growth rates and proliferation cycles for at least 5 years. Complementing SWAP-70 deficiency in one of these MEF clones, MEF1F2, by expressing human SWAP-70 resulted in fast growth of the cells after further cultivation for a long period. The resulting cells show a transformation phenotype, since they grow on top of each other and do not show contact inhibition. This phenotype was reverted when sanguinarine, a putative SWAP-70 inhibitor, was added. Two SWAP-70 expressing clones were examined in detail. Even after cell density became very high their cdc2 and NFκB were still activated suggesting that they do not stop growing. One of the clones formed colonies in soft agar and formed tumors in nude mice. Lately, one more clone became transformed being able to make colonies in soft agar. We maintain 4 human SWAP-70 expressing MEF1F2 cell lines. Three out of 4 clones exhibited transforming phenotypes. The mouse SWAP-70 gene also promoted transformation of MEFs. Taken together our data suggest that SWAP-70 is not a typical oncogene, but is required for spontaneous transformation of MEFs. - Highlights: • Mouse embryo fibroblasts (MEFs) lacking SWAP-70 do not cause spontaneous transform. • Adding back of SWAP-70 to SWAP-70-deficient MEFs induces spontaneous transformation. • SWAP-70 is required for spontaneous transformation of MEFs.

  9. Cell-surface glycoproteins of human sarcomas: differential expression in normal and malignant tissues and cultured cells

    International Nuclear Information System (INIS)

    Rettig, W.F.; Garin-Chesa, P.; Beresford, H.R.; Oettgen, H.F.; Melamed, M.R.; Old, L.J.

    1988-01-01

    Normal differentiation and malignant transformation of human cells are characterized by specific changes in surface antigen phenotype. In the present study, the authors have defined six cell-surface antigens of human sarcomas and normal mesenchymal cells, by using mixed hemadsorption assays and immunochemical methods for the analysis of cultured cells and immunohistochemical staining for the analysis of normal tissues and > 200 tumor specimens. Differential patterns of F19, F24, G171, G253, S5, and Thy-1 antigen expression were found to characterize (i) subsets of cultured sarcoma cell lines, (ii) cultured fibroblasts derived from various organs, (iii) normal resting and activated mesenchymal tissues, and (iv) sarcoma and nonmesenchymal tumor tissues. These results provide a basic surface antigenic map for cultured mesenchymal cells and mesenchymal tissues and permit the classification of human sarcomas according to their antigenic phenotypes

  10. Rac1 and Cdc42 are regulators of HRasV12-transformation and angiogenic factors in human fibroblasts

    International Nuclear Information System (INIS)

    Appledorn, Daniel M; Dao, Kim-Hien T; O'Reilly, Sandra; Maher, Veronica M; McCormick, J Justin

    2010-01-01

    The activities of Rac1 and Cdc42 are essential for HRas-induced transformation of rodent fibroblasts. What is more, expression of constitutively activated mutants of Rac1 and/or Cdc42 is sufficient for their malignant transformation. The role for these two Rho GTPases in HRas-mediated transformation of human fibroblasts has not been studied. Here we evaluated the contribution of Rac1 and Cdc42 to maintaining HRas-induced transformation of human fibroblasts, and determined the ability of constitutively activated mutants of Rac1 or Cdc42 to induce malignant transformation of a human fibroblast cell strain. Under the control of a tetracycline regulatable promoter, dominant negative mutants of Rac1 and Cdc42 were expressed in a human HRas-transformed, tumor derived fibroblast cell line. These cells were used to determine the roles of Rac1 and/or Cdc42 proteins in maintaining HRas-induced transformed phenotypes. Similarly, constitutively active mutants were expressed in a non-transformed human fibroblast cell strain to evaluate their potential to induce malignant transformation. Affymetrix GeneChip arrays were used for transcriptome analyses, and observed expression differences were subsequently validated using protein assays. Expression of dominant negative Rac1 and/or Cdc42 significantly altered transformed phenotypes of HRas malignantly transformed human fibroblasts. In contrast, expression of constitutively active mutants of Rac1 or Cdc42 was not sufficient to induce malignant transformation. Microarray analysis revealed that the expression of 29 genes was dependent on Rac1 and Cdc42, many of which are known to play a role in cancer. The dependence of two such genes, uPA and VEGF was further validated in both normoxic and hypoxic conditions. The results presented here indicate that expression of both Rac1 and Cdc42 is necessary for maintaining several transformed phenotypes in oncogenic HRas transformed human cells, including their ability to form tumors in athymic

  11. Rac1 and Cdc42 are regulators of HRasV12-transformation and angiogenic factors in human fibroblasts

    Directory of Open Access Journals (Sweden)

    Dao Kim-Hien T

    2010-01-01

    Full Text Available Abstract Background The activities of Rac1 and Cdc42 are essential for HRas-induced transformation of rodent fibroblasts. What is more, expression of constitutively activated mutants of Rac1 and/or Cdc42 is sufficient for their malignant transformation. The role for these two Rho GTPases in HRas-mediated transformation of human fibroblasts has not been studied. Here we evaluated the contribution of Rac1 and Cdc42 to maintaining HRas-induced transformation of human fibroblasts, and determined the ability of constitutively activated mutants of Rac1 or Cdc42 to induce malignant transformation of a human fibroblast cell strain. Methods Under the control of a tetracycline regulatable promoter, dominant negative mutants of Rac1 and Cdc42 were expressed in a human HRas-transformed, tumor derived fibroblast cell line. These cells were used to determine the roles of Rac1 and/or Cdc42 proteins in maintaining HRas-induced transformed phenotypes. Similarly, constitutively active mutants were expressed in a non-transformed human fibroblast cell strain to evaluate their potential to induce malignant transformation. Affymetrix GeneChip arrays were used for transcriptome analyses, and observed expression differences were subsequently validated using protein assays. Results Expression of dominant negative Rac1 and/or Cdc42 significantly altered transformed phenotypes of HRas malignantly transformed human fibroblasts. In contrast, expression of constitutively active mutants of Rac1 or Cdc42 was not sufficient to induce malignant transformation. Microarray analysis revealed that the expression of 29 genes was dependent on Rac1 and Cdc42, many of which are known to play a role in cancer. The dependence of two such genes, uPA and VEGF was further validated in both normoxic and hypoxic conditions. Conclusion(s The results presented here indicate that expression of both Rac1 and Cdc42 is necessary for maintaining several transformed phenotypes in oncogenic HRas

  12. 4-Hydroxyestradiol induces mammary epithelial cell transformation through Nrf2-mediated heme oxygenase-1 overexpression

    OpenAIRE

    Park, Sin-Aye; Lee, Mee-Hyun; Na, Hye-Kyung; Surh, Young-Joon

    2016-01-01

    Estrogen (17?-estradiol, E2) undergoes oxidative metabolism by CYP1B1 to form 4-hydroxyestradiol (4-OHE2), a putative carcinogenic metabolite of estrogen. Our previous study showed that 4-OHE2-induced production of reactive oxygen species contributed to neoplastic transformation of human breast epithelial (MCF-10A) cells. In this study, 4-OHE2, but not E2, increased the expression of heme oxygenase-1 (HO-1), a sensor and regulator of oxidative stress, in MCF-10A cells. Silencing the HO-1 gene...

  13. TGF-β induces the expression of the adaptor Ndfip1 to silence IL-4 production during iTreg cell differentiation.

    Science.gov (United States)

    Beal, Allison M; Ramos-Hernández, Natalia; Riling, Chris R; Nowelsky, Erin A; Oliver, Paula M

    2011-11-13

    Mice deficient in the adaptor Ndfip1 develop inflammation at sites of environmental antigen exposure. We show here that such mice had fewer inducible regulatory T cells (iT(reg) cells). In vitro, Ndfip1-deficient T cells expressed normal amounts of the transcription factor Foxp3 during the first 48 h of iT(reg) cell differentiation; however, this expression was not sustained. Abortive Foxp3 expression was caused by production of interleukin 4 (IL-4) by Ndfip1(-/-) cells. We found that Ndfip1 expression was transiently upregulated during iT(reg) cell differentiation in a manner dependent on transforming growth factor-β (TGF-β). Once expressed, Ndfip1 promoted degradation of the transcription factor JunB mediated by the E3 ubiquitin ligase Itch, thus preventing IL-4 production. On the basis of our data, we propose that TGF-β signaling induces Ndfip1 expression to silence IL-4 production, thus permitting iT(reg) cell differentiation.

  14. Whole-cell fungal transformation of precursors into dyes

    Directory of Open Access Journals (Sweden)

    Jarosz-Wilkołazka Anna

    2010-07-01

    Full Text Available Abstract Background Chemical methods of producing dyes involve extreme temperatures and unsafe toxic compounds. Application of oxidizing enzymes obtained from fungal species, for example laccase, is an alternative to chemical synthesis of dyes. Laccase can be replaced by fungal biomass acting as a whole-cell biocatalyst with properties comparable to the isolated form of the enzyme. The application of the whole-cell system simplifies the transformation process and reduces the time required for its completion. In the present work, four fungal strains with a well-known ability to produce laccase were tested for oxidation of 17 phenolic and non-phenolic precursors into stable and non-toxic dyes. Results An agar-plate screening test of the organic precursors was carried out using four fungal strains: Trametes versicolor, Fomes fomentarius, Abortiporus biennis, and Cerrena unicolor. Out of 17 precursors, nine were transformed into coloured substances in the presence of actively growing fungal mycelium. The immobilized fungal biomass catalyzed the transformation of 1 mM benzene and naphthalene derivatives in liquid cultures yielding stable and non-toxic products with good dyeing properties. The type of fungal strain had a large influence on the absorbance of the coloured products obtained after 48-hour transformation of the selected precursors, and the most effective was Fomes fomentarius (FF25. Whole-cell transformation of AHBS (3-amino-4-hydroxybenzenesulfonic acid into a phenoxazinone dye was carried out in four different systems: in aqueous media comprising low amounts of carbon and nitrogen source, in buffer, and in distilled water. Conclusions This study demonstrated the ability of four fungal strains belonging to the ecological type of white rot fungi to transform precursors into dyes. This paper highlights the potential of fungal biomass for replacing isolated enzymes as a cheaper industrial-grade biocatalyst for the synthesis of dyes and other

  15. Reactive oxygen species via redox signaling to PI3K/AKT pathway contribute to the malignant growth of 4-hydroxy estradiol-transformed mammary epithelial cells.

    Directory of Open Access Journals (Sweden)

    Victor O Okoh

    Full Text Available The purpose of this study was to investigate the effects of 17-β-estradiol (E2-induced reactive oxygen species (ROS on the induction of mammary tumorigenesis. We found that ROS-induced by repeated exposures to 4-hydroxy-estradiol (4-OH-E2, a predominant catechol metabolite of E2, caused transformation of normal human mammary epithelial MCF-10A cells with malignant growth in nude mice. This was evident from inhibition of estrogen-induced breast tumor formation in the xenograft model by both overexpression of catalase as well as by co-treatment with Ebselen. To understand how 4-OH-E2 induces this malignant phenotype through ROS, we investigated the effects of 4-OH-E2 on redox-sensitive signal transduction pathways. During the malignant transformation process we observed that 4-OH-E2 treatment increased AKT phosphorylation through PI3K activation. The PI3K-mediated phosphorylation of AKT in 4-OH-E2-treated cells was inhibited by ROS modifiers as well as by silencing of AKT expression. RNA interference of AKT markedly inhibited 4-OH-E2-induced in vitro tumor formation. The expression of cell cycle genes, cdc2, PRC1 and PCNA and one of transcription factors that control the expression of these genes - nuclear respiratory factor-1 (NRF-1 was significantly up-regulated during the 4-OH-E2-mediated malignant transformation process. The increased expression of these genes was inhibited by ROS modifiers as well as by silencing of AKT expression. These results indicate that 4-OH-E2-induced cell transformation may be mediated, in part, through redox-sensitive AKT signal transduction pathways by up-regulating the expression of cell cycle genes cdc2, PRC1 and PCNA, and the transcription factor - NRF-1. In summary, our study has demonstrated that: (i 4-OH-E2 is one of the main estrogen metabolites that induce mammary tumorigenesis and (ii ROS-mediated signaling leading to the activation of PI3K/AKT pathway plays an important role in the generation of 4-OH-E2

  16. MLL-ENL cooperates with SCF to transform primary avian multipotent cells.

    Science.gov (United States)

    Schulte, Cathleen E; von Lindern, Marieke; Steinlein, Peter; Beug, Hartmut; Wiedemann, Leanne M

    2002-08-15

    The MLL gene is targeted by chromosomal translocations, which give rise to heterologous MLL fusion proteins and are associated with distinct types of acute lymphoid and myeloid leukaemia. To determine how MLL fusion proteins alter the proliferation and/or differentiation of primary haematopoietic progenitors, we introduced the MLL-AF9 and MLL-ENL fusion proteins into primary chicken bone marrow cells. Both fusion proteins caused the sustained outgrowth of immature haematopoietic cells, which was strictly dependent on stem cell factor (SCF). The renewing cells have a long in vitro lifespan exceeding the Hayflick limit of avian cells. Analysis of clonal cultures identified the renewing cells as immature, multipotent progenitors, expressing erythroid, myeloid, lymphoid and stem cell surface markers. Employing a two-step commitment/differentiation protocol involving the controlled withdrawal of SCF, the MLL-ENL-transformed progenitors could be induced to terminal erythroid or myeloid differentiation. Finally, in cooperation with the weakly leukaemogenic receptor tyrosine kinase v-Sea, the MLL-ENL fusion protein gave rise to multilineage leukaemia in chicks, suggesting that other activated, receptor tyrosine kinases can substitute for ligand-activated c-Kit in vivo.

  17. Recovery of Epstein--Barr virus from nonproducer neonatal human lymphoid cell transformants

    International Nuclear Information System (INIS)

    Wilson, G.; Miller, G.

    1979-01-01

    Lymphoid cell lines (LCL) were established by infection of two batches of human umbilical cord lymphocytes with low multiplicities of the B95-8 strain of Epstein--Barr virus. Three of the 17 lines released minute mounts of transforming virus. The rest did not, nor did they make capsid antigen. However virus could be regularly recovered by lethal x-irradiation of transformed cells followed by cocultivation with primary human umbilical cord leukocytes. By this technique transforming activity could be identified in 15 of the 17 lines. These data indicate that these nonproducer human neonatal cell transformants established by EBV infection in vitro possess sufficient genetic information to code for production of biologically active mature virions. X rays alone failed to cause a detectable increase in the number of cells with capsid antigen or to enhance extracellular virus production. EBV-positive human serum blocked rescue if it was added during the first 2 to 4 hr after cocultivation, but not thereafter. Transforming virus could be recovered from x-rayed cells which were immediately thereafter lysed by freezing and thawing. These results suggest that recovery of virus following x-ray and cocultivation is not due to activation of the intracellular virus genome. Rather, it is likely that the method detects small numbers of virions which are cell associated. While transforming virus could regularly be rescued from lymphoblastoid cell lines resulting from in vitro transformation, attempts to rescue virus from Raji or EBV-converted BJAB cells were unsuccessful. This discrepancy suggests differences in genome complexity or in genome-cell interactions in different types of EBV-transformed cells

  18. Peroxisome Proliferator-Activated Receptor-γ Inhibits Transformed Growth of Non-Small Cell Lung Cancer Cells through Selective Suppression of Snail

    Directory of Open Access Journals (Sweden)

    Rashmi Choudhary

    2010-03-01

    Full Text Available Work from our laboratory and others has demonstrated that activation of the nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ inhibits transformed growth of non-small cell lung cancer (NSCLC cell lines in vitro and in vivo. We have demonstrated that activation of PPARγ promotes epithelial differentiation of NSCLC by increasing expression of E-cadherin, as well as inhibiting expression of COX-2 and nuclear factor-κB. The Snail family of transcription factors, which includes Snail (Snail1, Slug (Snail2, and ZEB1, is an important regulator of epithelial-mesenchymal transition, as well as cell survival. The goal of this study was to determine whether the biological responses to rosiglitazone, a member of the thiazolidinedione family of PPARγ activators, are mediated through the regulation of Snail family members. Our results indicate that, in two independent NSCLC cell lines, rosiglitazone specifically decreased expression of Snail, with no significant effect on either Slug or ZEB1. Suppression of Snail using short hairpin RNA silencing mimicked the effects of PPARγ activation, in inhibiting anchorage-independent growth, promoting acinar formation in three-dimensional culture, and inhibiting invasiveness. This was associated with the increased expression of E-cadherin and decreased expression of COX-2 and matrix metaloproteinases. Conversely, overexpression of Snail blocked the biological responses to rosiglitazone, increasing anchorage-independent growth, invasiveness, and promoting epithelial-mesenchymal transition. The suppression of Snail expression by rosiglitazone seemed to be independent of GSK-3 signaling but was rather mediated through suppression of extracellular signal-regulated kinase activity. These findings suggest that selective regulation of Snail may be critical in mediating the antitumorigenic effects of PPARγ activators.

  19. Islet amyloid polypeptide and insulin expression are controlled differently in primary and transformed islet cells

    DEFF Research Database (Denmark)

    Madsen, O D; Michelsen, Bo Thomas; Westermark, P

    1991-01-01

    in unstable heterogeneous clones such as NHI-6F. This clone is composed of primarily glucagon-producing cells in vitro, but insulin gene expression becomes dominant after passage in vivo. Interestingly, IAPP was hyperexpressed with glucagon under in vitro conditions in this clone. We conclude that the tissue...

  20. Distinct protease pathways control cell shape and apoptosis in v-src-transformed quail neuroretina cells

    International Nuclear Information System (INIS)

    Neel, Benjamin D.; Aouacheria, Abdel; Nouvion, Anne-Laure; Ronot, Xavier; Gillet, Germain

    2005-01-01

    Intracellular proteases play key roles in cell differentiation, proliferation and apoptosis. In nerve cells, little is known about their relative contribution to the pathways which control cell physiology, including cell death. Neoplastic transformation of avian neuroretina cells by p60 v-src tyrosine kinase results in dramatic morphological changes and deregulation of apoptosis. To identify the proteases involved in the cellular response to p60 v-src , we evaluated the effect of specific inhibitors of caspases, calpains and the proteasome on cell shape changes and apoptosis induced by p60 v-src inactivation in quail neuroretina cells transformed by tsNY68, a thermosensitive strain of Rous sarcoma virus. We found that the ubiquitin-proteasome pathway is recruited early after p60 v-src inactivation and is critical for morphological changes, whereas caspases are essential for cell death. This study provides evidence that distinct intracellular proteases are involved in the control of the morphology and fate of v-src-transformed cells

  1. Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tracy Chui-hsu; Craise, L.M; Prioleau, J.C.; Stampfer, M.R.; Rhim, J.S.

    1990-11-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude nice. Neoplastic transformation was achieved by irradiation cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level. 15 refs., 9 figs., 2 tabs.

  2. Chromosomal changes in cultured human epithelial cells transformed by low- and high-LET radiation

    International Nuclear Information System (INIS)

    Yang, Tracy Chui-hsu; Craise, L.M; Prioleau, J.C.; Stampfer, M.R.; Rhim, J.S.

    1990-11-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude nice. Neoplastic transformation was achieved by irradiation cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level. 15 refs., 9 figs., 2 tabs

  3. Epithelium Expressing the E7 Oncoprotein of HPV16 Attracts Immune-Modulatory Dendritic Cells to the Skin and Suppresses Their Antigen-Processing Capacity.

    Directory of Open Access Journals (Sweden)

    Janin Chandra

    Full Text Available Antigen presenting cells (APCs in skin can promote either antigen-specific effector functions or antigen tolerance, and thus determine clearance or persistence of cutaneous viral infections. Human papillomavirus (HPV infections can persist in squamous epithelium in immunocompetent individuals, and some persisting HPV infections, particularly with HPV16, promote malignant epithelial transformation. Here, we investigate whether local expression of the HPV16 protein most associated with malignant transformation, HPV16-E7, affects the phenotype and function of APC subsets in the skin. We demonstrate an expanded population of Langerhans cells in HPV16-E7 transgenic skin with distinct cell surface markers which express immune-modulatory enzymes and cytokines not expressed by cells from non transgenic skin. Furthermore, HPV16-E7 transgene expression in keratinocytes attracts new APC subsets to the epidermis. In vivo migration and transport of antigen to the draining lymph node by these APCs is markedly enhanced in HPV16-E7 expressing skin, whereas antigen-processing, as measured by proteolytic cleavage of DQ-OVA and activation of T cells in vivo by APCs, is significantly impaired. These data suggest that local expression of HPV16-E7 in keratinocytes can contribute to persisting infection with this oncogenic virus, by altering the phenotype and function of local APCs.

  4. TGF-beta3 is expressed in taste buds and inhibits proliferation of primary cultured taste epithelial cells.

    Science.gov (United States)

    Nakamura, Shin-ichi; Kawai, Takayuki; Kamakura, Takashi; Ookura, Tetsuya

    2010-01-01

    Transforming growth factor-betas (TGF-betas), expressed in various tissues, play important roles in embryonic development and adult tissue homeostasis through their effects on cell proliferation, cell differentiation, cell death, and cell motility. However, expression of TGF-beta signaling components and their biological effect on taste epithelia has not been elucidated. We performed expression analysis of TGF-beta signaling components in taste epithelia and found that the TGF-beta3 mRNA was specifically expressed in taste buds. Type II TGF-betas receptor (TbetaR-II) mRNA was specifically expressed in the tongue epithelia including the taste epithelia. To elucidate the biological function of TGF-beta3 in taste epithelia, we performed proliferation assay with primary cultured taste epithelial cells. In the presence of TGF-beta3, percentage of BrdU-labeled cells decreased significantly, suggesting that the TGF-beta3 inhibited the proliferation of cultured taste epithelial cells through inhibiting cell-cycle entry into S phase. By quantitative reverse transcription-polymerase chain reaction assay, we found that the TGF-beta3 resulted in an increased level of expression of p15Ink4b and p21Cip1, suggesting that the TGF-beta3 inhibited the taste epithelial cell proliferation through inhibiting G1cyclin-Cdk complexes. Taken together, these results suggested that the TGF-beta3 may regulate taste epithelial cell homeostasis through controlling cell proliferation.

  5. Transforming growth factor-beta, but not ciliary neurotrophic factor, inhibits DNA synthesis of adrenal medullary cells in vitro

    DEFF Research Database (Denmark)

    Wolf, N; Krohn, K; Bieger, S

    1999-01-01

    by the neuroendocrine chromaffin cells, which also express the transforming growth factor-beta receptor type II. In contrast to the developmentally related sympathetic neurons, chromaffin cells continue to proliferate throughout postnatal life. Using 5-bromo-2'-deoxyuridine pulse labeling and tyrosine hydroxylase...... immunocytochemistry as a marker for young postnatal rat chromaffin cells, we show that treatment with fibroblast growth factor-2 (1 nM) and insulin-like growth factor-II (10 nM) increased the fraction of 5-bromo-2'-deoxyuridine-labeled nuclei from 1% to about 40% of the cells in the absence of serum. In the presence...... of fibroblast growth factor-2 and insulin-like growth factor-II, transforming growth factor-beta1 (0.08 nM) reduced 5-bromo-2'-deoxyuridine labeling by about 50%, without interfering with chromaffin cell survival or death. Doses lower and higher than 0.08 nM were less effective. Similar effects were seen...

  6. Mitochondrial clearance by the STK38 kinase supports oncogenic Ras-induced cell transformation

    Science.gov (United States)

    Bettoun, Audrey; Surdez, Didier; Vallerand, David; Gundogdu, Ramazan; Sharif, Ahmad A.D.; Gomez, Marta; Cascone, Ilaria; Meunier, Brigitte; White, Michael A.; Codogno, Patrice; Parrini, Maria Carla; Camonis, Jacques H.; Hergovich, Alexander

    2016-01-01

    Oncogenic Ras signalling occurs frequently in many human cancers. However, no effective targeted therapies are currently available to treat patients suffering from Ras-driven tumours. Therefore, it is imperative to identify downstream effectors of Ras signalling that potentially represent promising new therapeutic options. Particularly, considering that autophagy inhibition can impair the survival of Ras-transformed cells in tissue culture and mouse models, an understanding of factors regulating the balance between autophagy and apoptosis in Ras-transformed human cells is needed. Here, we report critical roles of the STK38 protein kinase in oncogenic Ras transformation. STK38 knockdown impaired anoikis resistance, anchorage-independent soft agar growth, and in vivo xenograft growth of Ras-transformed human cells. Mechanistically, STK38 supports Ras-driven transformation through promoting detachment-induced autophagy. Even more importantly, upon cell detachment STK38 is required to sustain the removal of damaged mitochondria by mitophagy, a selective autophagic process, to prevent excessive mitochondrial reactive oxygen species production that can negatively affect cancer cell survival. Significantly, knockdown of PINK1 or Parkin, two positive regulators of mitophagy, also impaired anoikis resistance and anchorage-independent growth of Ras-transformed human cells, while knockdown of USP30, a negative regulator of PINK1/Parkin-mediated mitophagy, restored anchorage-independent growth of STK38-depleted Ras-transformed human cells. Therefore, our findings collectively reveal novel molecular players that determine whether Ras-transformed human cells die or survive upon cell detachment, which potentially could be exploited for the development of novel strategies to target Ras-transformed cells. PMID:27283898

  7. A new variance stabilizing transformation for gene expression data analysis.

    Science.gov (United States)

    Kelmansky, Diana M; Martínez, Elena J; Leiva, Víctor

    2013-12-01

    In this paper, we introduce a new family of power transformations, which has the generalized logarithm as one of its members, in the same manner as the usual logarithm belongs to the family of Box-Cox power transformations. Although the new family has been developed for analyzing gene expression data, it allows a wider scope of mean-variance related data to be reached. We study the analytical properties of the new family of transformations, as well as the mean-variance relationships that are stabilized by using its members. We propose a methodology based on this new family, which includes a simple strategy for selecting the family member adequate for a data set. We evaluate the finite sample behavior of different classical and robust estimators based on this strategy by Monte Carlo simulations. We analyze real genomic data by using the proposed transformation to empirically show how the new methodology allows the variance of these data to be stabilized.

  8. Over-expression of Oct4 and Sox2 transcription factors enhances differentiation of human umbilical cord blood cells in vivo

    International Nuclear Information System (INIS)

    Guseva, Daria; Rizvanov, Albert A.; Salafutdinov, Ilnur I.; Kudryashova, Nezhdana V.; Palotás, András; Islamov, Rustem R.

    2014-01-01

    Highlights: • Gene and cell-based therapies comprise innovative aspects of regenerative medicine. • Genetically modified hUCB-MCs enhanced differentiation of cells in a mouse model of ALS. • Stem cells successfully transformed into micro-glial and endothelial lines in spinal cords. • Over-expressing oct4 and sox2 also induced production of neural marker PGP9.5. • Formation of new nerve cells, secreting trophic factors and neo-vascularisation could improve symptoms in ALS. - Abstract: Gene and cell-based therapies comprise innovative aspects of regenerative medicine. Even though stem cells represent a highly potential therapeutic strategy, their wide-spread exploitation is marred by ethical concerns, potential for malignant transformation and a plethora of other technical issues, largely restricting their use to experimental studies. Utilizing genetically modified human umbilical cord blood mono-nuclear cells (hUCB-MCs), this communication reports enhanced differentiation of transplants in a mouse model of amyotrophic lateral sclerosis (ALS). Over-expressing Oct4 and Sox2 induced production of neural marker PGP9.5, as well as transformation of hUCB-MCs into micro-glial and endothelial lines in ALS spinal cords. In addition to producing new nerve cells, providing degenerated areas with trophic factors and neo-vascularisation might prevent and even reverse progressive loss of moto-neurons and skeletal muscle paralysis

  9. Over-expression of Oct4 and Sox2 transcription factors enhances differentiation of human umbilical cord blood cells in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Guseva, Daria [Kazan State Medical University, Kazan, Republic of Tatarstan (Russian Federation); Hannover Medical School, Hannover (Germany); Rizvanov, Albert A.; Salafutdinov, Ilnur I.; Kudryashova, Nezhdana V. [Kazan Federal University, Kazan, Republic of Tatarstan (Russian Federation); Palotás, András, E-mail: palotas@asklepios-med.eu [Kazan Federal University, Kazan, Republic of Tatarstan (Russian Federation); Asklepios-Med (Private Medical Practice and Research Center), Szeged (Hungary); Islamov, Rustem R., E-mail: islamru@yahoo.com [Kazan State Medical University, Kazan, Republic of Tatarstan (Russian Federation)

    2014-09-05

    Highlights: • Gene and cell-based therapies comprise innovative aspects of regenerative medicine. • Genetically modified hUCB-MCs enhanced differentiation of cells in a mouse model of ALS. • Stem cells successfully transformed into micro-glial and endothelial lines in spinal cords. • Over-expressing oct4 and sox2 also induced production of neural marker PGP9.5. • Formation of new nerve cells, secreting trophic factors and neo-vascularisation could improve symptoms in ALS. - Abstract: Gene and cell-based therapies comprise innovative aspects of regenerative medicine. Even though stem cells represent a highly potential therapeutic strategy, their wide-spread exploitation is marred by ethical concerns, potential for malignant transformation and a plethora of other technical issues, largely restricting their use to experimental studies. Utilizing genetically modified human umbilical cord blood mono-nuclear cells (hUCB-MCs), this communication reports enhanced differentiation of transplants in a mouse model of amyotrophic lateral sclerosis (ALS). Over-expressing Oct4 and Sox2 induced production of neural marker PGP9.5, as well as transformation of hUCB-MCs into micro-glial and endothelial lines in ALS spinal cords. In addition to producing new nerve cells, providing degenerated areas with trophic factors and neo-vascularisation might prevent and even reverse progressive loss of moto-neurons and skeletal muscle paralysis.

  10. Regulatory T cells protect mice against coxsackievirus-induced myocarditis through the transforming growth factor beta-coxsackie-adenovirus receptor pathway.

    Science.gov (United States)

    Shi, Yu; Fukuoka, Masahiro; Li, Guohua; Liu, Youan; Chen, Manyin; Konviser, Michael; Chen, Xin; Opavsky, Mary Anne; Liu, Peter P

    2010-06-22

    Coxsackievirus B3 infection is an excellent model of human myocarditis and dilated cardiomyopathy. Cardiac injury is caused either by a direct cytopathic effect of the virus or through immune-mediated mechanisms. Regulatory T cells (Tregs) play an important role in the negative modulation of host immune responses and set the threshold of autoimmune activation. This study was designed to test the protective effects of Tregs and to determine the underlying mechanisms. Carboxyfluorescein diacetate succinimidyl ester-labeled Tregs or naïve CD4(+) T cells were injected intravenously once every 2 weeks 3 times into mice. The mice were then challenged with intraperitoneal coxsackievirus B3 immediately after the last cell transfer. Transfer of Tregs showed higher survival rates than transfer of CD4(+) T cells (P=0.0136) but not compared with the PBS injection group (P=0.0589). Interestingly, Tregs also significantly decreased virus titers and inflammatory scores in the heart. Transforming growth factor-beta and phosphorylated AKT were upregulated in Tregs-transferred mice and coxsackie-adenovirus receptor expression was decreased in the heart compared with control groups. Transforming growth factor-beta decreased coxsackie-adenovirus receptor expression and inhibited coxsackievirus B3 infection in HL-1 cells and neonatal cardiac myocytes. Splenocytes collected from Treg-, CD4(+) T-cell-, and PBS-treated mice proliferated equally when stimulated with heat-inactivated virus, whereas in the Treg group, the proliferation rate was reduced significantly when stimulated with noninfected heart tissue homogenate. Adoptive transfer of Tregs protected mice from coxsackievirus B3-induced myocarditis through the transforming growth factor beta-coxsackie-adenovirus receptor pathway and thus suppresses the immune response to cardiac tissue, maintaining the antiviral immune response.

  11. Expression of Podoplanin in Laryngeal Squamous Cell Carcinoma and Dysplasia.

    Science.gov (United States)

    Ibrahim, Badawia Bayoumy; Salem, Mostafa Mohamed; Khairy, Rasha Ahmed; Al Gunaid, Reema Abdul Rahman

    2017-05-01

    In human cancers, podoplanin expression and its correlation with tumour invasive potential raise its possible role as a diagnostic and prognostic marker for cancer. To investigate the immunohistochemical expression of podoplanin in laryngeal Squamous Cell Carcinoma (SCC) and dysplasia. This study included a total of 60 archived, formalin fixed, paraffin embedded tissue blocks of 40 cases of laryngeal SCC and 20 cases of dysplastic lesions. The samples were immunohistochemically analysed for podoplanin expression. Podoplanin expression was significantly higher in laryngeal SCC (90%) than laryngeal dysplastic lesions (55%) (p-value=0.002). The expression of podoplanin was significantly increased with the higher grades of dysplasia (p-value=0.016). A significant positive correlation was detected between podoplanin expression in laryngeal SCC and depth of tumour invasion (p-value=0.035), and stage (p-value=0.026). The high expression of podoplanin in laryngeal SCC and its significant correlation with poor prognostic parameters recommends podoplanin as a prognostic marker in laryngeal SCC. In addition, increased podoplanin expression with higher grades of dysplasia, supports its role in malignant transformation and allows us to recommend its evaluation in premalignant lesions.

  12. Differential cellular responses by oncogenic levels of c-Myc expression in long-term confluent retinal pigment epithelial cells.

    Science.gov (United States)

    Wang, Yiping; Cheng, Xiangdong; Samma, Muhammad Kaleem; Kung, Sam K P; Lee, Clement M; Chiu, Sung Kay

    2018-06-01

    c-Myc is a highly pleiotropic transcription factor known to control cell cycle progression, apoptosis, and cellular transformation. Normally, ectopic expression of c-Myc is associated with promoting cell proliferation or triggering cell death via activating p53. However, it is not clear how the levels of c-Myc lead to different cellular responses. Here, we generated a series of stable RPE cell clones expressing c-Myc at different levels, and found that consistent low level of c-Myc induced cellular senescence by activating AP4 in post-confluent RPE cells, while the cells underwent cell death at high level of c-Myc. In addition, high level of c-Myc could override the effect of AP4 on cellular senescence. Further knockdown of AP4 abrogated senescence-like phenotype in cells expressing low level of c-Myc, and accelerated cell death in cells with medium level of c-Myc, indicating that AP4 was required for cellular senescence induced by low level of c-Myc.

  13. Gene regulation mediating fiber-type transformation in skeletal muscle cells is partly glucose- and ChREBP-dependent.

    Science.gov (United States)

    Hanke, Nina; Scheibe, Renate J; Manukjan, Georgi; Ewers, David; Umeda, Patrick K; Chang, Kin-Chow; Kubis, Hans-Peter; Gros, Gerolf; Meissner, Joachim D

    2011-03-01

    Adaptations in the oxidative capacity of skeletal muscle cells can occur under several physiological or pathological conditions. We investigated the effect of increasing extracellular glucose concentration on the expression of markers of energy metabolism in primary skeletal muscle cells and the C2C12 muscle cell line. Growth of myotubes in 25mM glucose (high glucose, HG) compared with 5.55mM led to increases in the expression and activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a marker of glycolytic energy metabolism, while oxidative markers peroxisome proliferator-activated receptor γ coactivator 1α and citrate synthase decreased. HG induced metabolic adaptations as are seen during a slow-to-fast fiber transformation. Furthermore, HG increased fast myosin heavy chain (MHC) IId/x but did not change slow MHCI/β expression. Protein phosphatase 2A (PP2A) was shown to mediate the effects of HG on GAPDH and MHCIId/x. Carbohydrate response element-binding protein (ChREBP), a glucose-dependent transcription factor downstream of PP2A, partially mediated the effects of glucose on metabolic markers. The glucose-induced increase in PP2A activity was associated with an increase in p38 mitogen-activated protein kinase activity, which presumably mediates the increase in MHCIId/x promoter activity. Liver X receptor, another possible mediator of glucose effects, induced only an incomplete metabolic shift, mainly increasing the expression of the glycolytic marker. Taken together, HG induces a partial slow-to-fast transformation comprising metabolic enzymes together with an increased expression of MHCIId/x. This work demonstrates a functional role for ChREBP in determining the metabolic type of muscle fibers and highlights the importance of glucose as a signaling molecule in muscle. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Endothelial Cell Migration and Vascular Endothelial Growth Factor Expression Are the Result of Loss of Breast Tissue Polarity

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Amy; Cuevas, Ileana; Kenny, Paraic A; Miyake, Hiroshi; Mace, Kimberley; Ghajar, Cyrus; Boudreau, Aaron; Bissell, Mina; Boudreau, Nancy

    2009-05-26

    Recruiting a new blood supply is a rate-limiting step in tumor progression. In a three-dimensional model of breast carcinogenesis, disorganized, proliferative transformed breast epithelial cells express significantly higher expression of angiogenic genes compared with their polarized, growth-arrested nonmalignant counterparts. Elevated vascular endothelial growth factor (VEGF) secretion by malignant cells enhanced recruitment of endothelial cells (EC) in heterotypic cocultures. Significantly, phenotypic reversion of malignant cells via reexpression of HoxD10, which is lost in malignant progression, significantly attenuated VEGF expression in a hypoxia-inducible factor 1{alpha}-independent fashion and reduced EC migration. This was due primarily to restoring polarity: forced proliferation of polarized, nonmalignant cells did not induce VEGF expression and EC recruitment, whereas disrupting the architecture of growth-arrested, reverted cells did. These data show that disrupting cytostructure activates the angiogenic switch even in the absence of proliferation and/or hypoxia and restoring organization of malignant clusters reduces VEGF expression and EC activation to levels found in quiescent nonmalignant epithelium. These data confirm the importance of tissue architecture and polarity in malignant progression.

  15. Transformation of Epithelial Ovarian Cancer Stemlike Cells into Mesenchymal Lineage via EMT Results in Cellular Heterogeneity and Supports Tumor Engraftment

    Science.gov (United States)

    Jiang, Hua; Lin, Xiaolong; Liu, Yingtao; Gong, Wenjia; Ma, Xiaoling; Yu, Yinhua; Xie, Yi; Sun, Xiaoxi; Feng, Youji; Janzen, Viktor; Chen, Tong

    2012-01-01

    Ovarian cancers are heterogeneous and contain stemlike cells that are able to self-renew and are responsible for sustained tumor growth. Metastasis in the peritoneal cavity occurs more frequently in ovarian cancer than in other malignancies, but the underlying mechanism remains largely unknown. We have identified that ovarian cancer stemlike cells (CSCs), which were defined as side population (SP) cells, were present in patients’ ascitic fluid and mesenchymally transformed cell lines, ES-2 and HO-8910PM. SP cells, which were sorted from both cell lines and implanted into immunocompromised mice, were localized to the xenografted tumor boundary. In addition, SP cells exhibited an epithelial phenotype and showed a distinct gene expression profile with reduced expression of cell adhesion molecules (CAMs), indicating that SP cells exert an important role in ovarian cancer progression on the basis of their delicate interaction with the surrounding microenvironment and anatomical localization in tumors. In contrast, non-SP cells exhibited a more mesenchymal phenotype and showed more increased invasive potential than SP cells. This heterogeneity was observed as an endogenous transformation via the epithelial–mesenchymal transition (EMT) process. Inhibition of the EMT process by Snail1 silencing reduced the SP cell frequency, and affected their invasive capacity and engraftment. These findings illustrate the interplay between epithelial ovarian CSCs and the EMT, and exert a link to explain tumor heterogeneity and its necessity for ovarian cancer maintenance, metastasis and progression. PMID:22801793

  16. X-radiation-induced transformation in a C3H mouse embryo-derived cell line

    International Nuclear Information System (INIS)

    Terzaghi, M.; Little, J.B.

    1976-01-01

    Reproducible x-ray-induced oncogenic transformation has been demonstrated in an established cell line of mouse embryo fibroblasts. Cells derived from transformed foci formed malignant tumors when injected into syngeneic hosts. An exponential increase in the number of transformants per viable cell occurred with doses of up to 400 rads of x-radiation. The transformation frequency in exponentially growing cultures remained constant at 2.3 x 10 -3 following doses of 400 to 1500 rads. There was little change in survival following x-ray doses up to 300 rads. Doses greater than 300 rads were associated with an exponential decline in survival; the D 0 for the survival curve was 175 rads. Transformation frequency varied with changes in the number of viable cells seeded per dish. There was about a 10-fold decline in the transformation frequency when the number of cells was increased from 400 to 1000 viable cells/100-mm Petri dish. Below this density range there was little change in transformation frequency. The presence of lethally preirradiated cells was not associated with an enhancement of transformation in irradiated cells or with the induction of transformation in unirradiated cell cultures. Amphotericin B (Fungizone) inhibited the appearance of transformants when added to the culture medium within 2 to 3 weeks after initiation of the experiment

  17. Effects of ultrasound on Transforming Growth Factor-beta genes in bone cells

    Directory of Open Access Journals (Sweden)

    J Harle

    2005-12-01

    Full Text Available Therapeutic ultrasound (US is a widely used form of biophysical stimulation that is increasingly applied to promote fracture healing. Transforming growth factor-beta (TGF-beta, which is encoded by three related but different genes, is known to play a major part in bone growth and repair. However, the effects of US on the expression of the TGF-beta genes and the physical acoustic mechanisms involved in initiating changes in gene expression in vitro, are not yet known. The present study demonstrates that US had a differential effect on these TGF-beta isoforms in a human osteoblast cell line, with the highest dose eliciting the most pronounced up-regulation of both TGF-beta1 and TGF-beta3 at 1 hour after treatment and thereafter declining. In contrast, US had no effect on TGF-beta2 expression. Fluid streaming rather than thermal effects or cavitation was found to be the most likely explanation for the gene responses observed in vitro.

  18. Human cell transformation in the study of sunlight-induced cancers in the skin of man

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Bennett, P.V.

    1988-01-01

    Human cell transformation provides a powerful approach to understanding - at the cellular and molecular levels - induction of cancers in the skin of man. A principal approach to this problem is the direct transformation of human skin cells by exposure to ultraviolet and/or near-UV radiation. The frequency of human cells transformed to anchorage independence increases with radiation exposure; the relative transforming efficiencies of different wavelengths implies that direct absorption by nucleic acids is a primary initial event. Partial reversal of potential transforming lesions by photoreactivation suggests that pyrimidine dimers, as well as other lesions, are important in UV transformation of human cells. Human cells can also be transformed by transfection with cloned oncogenes, or with DNAs from tumors or tumor cell lines. Cells treated by the transfection procedure (but without DNA) or cells transfected with DNAs from normal mammalian cells or tissues show only background levels of transformation. Human cells can be transformed to anchorage-independent growth by DNAs ineffective in transformation of NIH 3T3 cells (including most human skin cancers), permitting the analysis of oncogenic molecular changes even in tumor DNAs difficult or impossible to analyze in rodent cell systems. 29 refs.; 4 figs.; 1 table

  19. DNA alkylating agents alleviate silencing of class II transactivator gene expression in L1210 lymphoma cells.

    Science.gov (United States)

    Murphy, Shawn P; Holtz, Renae; Lewandowski, Nicole; Tomasi, Thomas B; Fuji, Hiroshi

    2002-09-15

    MHC class II (Ia) Ag expression is inversely correlated with tumorigenicity and directly correlated with immunogenicity in clones of the mouse L1210 lymphoma (1 ). Understanding the mechanisms by which class II Ag expression is regulated in L1210 lymphoma may facilitate the development of immunotherapeutic approaches for the treatment of some types of lymphoma and leukemia. This study demonstrates that the variation in MHC class II Ag expression among clones of L1210 lymphoma is due to differences in the expression of the class II transactivator (CIITA). Analysis of stable hybrids suggests that CIITA expression is repressed by a dominant mechanism in class II-negative L1210 clones. DNA-alkylating agents such as ethyl methanesulfonate and the chemotherapeutic drug melphalan activate CIITA and class II expression in class II negative L1210 cells, and this effect appears to be restricted to transformed cell lines derived from the early stages of B cell ontogeny. Transient transfection assays demonstrated that the CIITA type III promoter is active in class II(-) L1210 cells, despite the fact that the endogenous gene is not expressed, which suggests that these cells have all of the transacting factors necessary for CIITA transcription. An inverse correlation between methylation of the CIITA transcriptional regulatory region and CIITA expression was observed among L1210 clones. Furthermore, 5-azacytidine treatment activated CIITA expression in class II-negative L1210 cells. Collectively, our results suggest that 1) CIITA gene expression is repressed in class II(-) L1210 cells by methylation of the CIITA upstream regulatory region, and 2) treatment with DNA-alkylating agents overcomes methylation-based silencing of the CIITA gene in L1210 cells.

  20. Alpha-particles induce preneoplastic transformation of rat tracheal epithelial cells in culture

    International Nuclear Information System (INIS)

    Thomassen, D.G.; Seiler, F.A.; Shyr, L.-J.; Griffith, W.C.

    1990-01-01

    To characterize the potential role of high-l.e.t. radiation in respiratory carcinogenesis, the cytotoxic and transforming potency of 5.5 MeV α-particles from electroplated sources of 238 Pu were determined using primary cultures of rat tracheal epithelial cells. RBE for cell killing by α-particles versus X-rays varied with dose, and ranged between 4 and 1.5 for α doses in the range 0.2-4 Gy. At equally toxic doses (relative survival 0.18-0.2), all three agents induced similar frequencies of preneoplastic transformation. For preneoplastic transformation induced by doses of α- and X-radiations giving 80 per cent toxicity, an α RBE of 2.4 was derived. The similar RBEs for cell killing and for preneoplastic transformation suggest an association between the type or degree of radiation-induced damage responsible for both cell killing and cell transformation. (author)

  1. Malignant transformation of guinea pig cells after exposure to ultraviolet-irradiated guinea pig cytomegalovirus

    International Nuclear Information System (INIS)

    Isom, H.C.; Mummaw, J.; Kreider, J.W.

    1983-01-01

    Guinea pig cells were malignantly transformed in vitro by ultraviolet (uv)-irradiated guinea pig cytomegalovirus (GPCMV). When guinea pig hepatocyte monolayers were infected with uv-irradiated GPCMV, three continuous epithelioid cell lines which grew in soft agarose were established. Two independently derived GPCMV-transformed liver cells and a cell line derived from a soft agarose clone of one of these lines induced invasive tumors when inoculated subcutaneously or intraperitoneally into nude mice. The tumors were sarcomas possibly derived from hepatic stroma or sinusoid. Transformed cell lines were also established after infection of guinea pig hepatocyte monolayers with human cytomegalovirus (HCMV) or simian virus 40 (SV40). These cell lines also formed colonies in soft agarose and induced sarcomas in nude mice. It is concluded that (i) GPCMV can malignantly transform guinea pig cells; (ii) cloning of GPCMV-transformed cells in soft agarose produced cells that induced tumors with a shorter latency period but with no alteration in growth rate or final tumor size; and (iii) the tumors produced by GPCMV-and HCMV-transformed guinea pig cells were more similar to each other in growth rate than to those induced by SV40-transformed guinea pig cells

  2. Multiple abiotic stress tolerance of the transformants yeast cells and the transgenic Arabidopsis plants expressing a novel durum wheat catalase.

    Science.gov (United States)

    Feki, Kaouthar; Kamoun, Yosra; Ben Mahmoud, Rihem; Farhat-Khemakhem, Ameny; Gargouri, Ali; Brini, Faiçal

    2015-12-01

    Catalases are reactive oxygen species scavenging enzymes involved in response to abiotic and biotic stresses. In this study, we described the isolation and functional characterization of a novel catalase from durum wheat, designed TdCAT1. Molecular Phylogeny analyses showed that wheat TdCAT1 exhibited high amino acids sequence identity to other plant catalases. Sequence homology analysis showed that TdCAT1 protein contained the putative calmodulin binding domain and a putative conserved internal peroxisomal targeting signal PTS1 motif around its C-terminus. Predicted three-dimensional structural model revealed the presence of four putative distinct structural regions which are the N-terminal arm, the β-barrel, the wrapping and the α-helical domains. TdCAT1 protein had the heme pocket that was composed by five essential residues. TdCAT1 gene expression analysis showed that this gene was induced by various abiotic stresses in durum wheat. The expression of TdCAT1 in yeast cells and Arabidopsis plants conferred tolerance to several abiotic stresses. Compared with the non-transformed plants, the transgenic lines maintained their growth and accumulated more proline under stress treatments. Furthermore, the amount of H2O2 was lower in transgenic lines, which was due to the high CAT and POD activities. Taken together, these data provide the evidence for the involvement of durum wheat catalase TdCAT1 in tolerance to multiple abiotic stresses in crop plants. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  3. Intervention of oxygen-control ability to radiation sensitivity, cell aging and cell transformation

    International Nuclear Information System (INIS)

    Yoshii, Hanako; Watanabe, Masami

    2009-01-01

    Oxygen is essential for life, and cells have therefore developed numerous adaptive responses to oxygen change. Here, we examined the difference in oxygen-control functions of human (HE), mouse (ME), and Syrian hamster embryo (SHE) cells cultured under different oxygen conditions (0.5%, 2% and 20%), and also examined whether oxygen tensions contributed to cellular lifespan and transformation. HE cells had their replicative lifespan slightly extended under hypoxic (0.5% and 2% oxygen) conditions, but were not immortalized under any of the oxygen concentrations. On the other hand, although ME cells cultured under 20% oxygen tension decreased their proliferation potency temporarily at early stage, all rodent cells were immortalized and acquired anchorage-independency, regardless of oxygen tension. These results suggest that cellular oxygen control function is related to sensitivities cellular immortalization and transformation. To understand intervention of oxygen control ability on cellular immortalization and transformation, we examined the intracellular oxidative level, mitochondria functions and radiation sensitivity. Intracellular oxidative levels of hypoxically cultured rodent cells were significantly enhanced. Mitochondrial membrane potential was altered depend on oxygen tensions, but the change was not parallel to mitochondria number in rodent cells. ME cells were particularly sensitive to oxygen change, and showed a clear oxygen effect on the X-ray survival. However, there was no difference in frequency of radiation-induced micronuclei between HE and ME cells. These results suggest that the response to oxygen change differs markedly in HE and rodent cells. (author)

  4. Induction of gastric cancer cell adhesion through transforming growth factor-beta1-mediated peritoneal fibrosis

    Directory of Open Access Journals (Sweden)

    Ma Xiao-Yang

    2010-10-01

    Full Text Available Abstract Background Peritoneal dissemination is one of the main causes of death in gastric cancer patients. Transforming growth factor-beta1 (TGF-β1, one of the most potent fibrotic stimuli for mesothelial cells, may play a key role in this processing. The purpose of this study is to elucidate the effects of TGF-β1 on regulation of gastric cancer adhesion to mesothelial cells. Methods Peritoneal tissues and peritoneal wash fluid were obtained for hematoxylin and eosin staining or ELISA to measure fibrosis and TGF-β1 levels, respectively. The peritoneal mesothelial cell line, HMrSV5, was used to determine the role of TGF-β1 in regulation of gastric cancer cell adhesion to mesothelial cells and expression of collagen, fibronectin, and Smad 2/3 by using adhesion assay, western blot, and RT-PCR. Results The data showed that TGF-β1 treatment was able to induce collagen III and fibronectin expression in the mesothelial cells, which was associated with an increased adhesion ability of gastric cancer cells, but knockdown of minimal sites of cell binding domain of extracellular matrix can partially inhibit these effects. Conclusion Peritoneal fibrosis induced by TGF-β1 may provide a favorable environment for the dissemination of gastric cancer.

  5. Matrix Metallopeptidase 14 Plays an Important Role in Regulating Tumorigenic Gene Expression and Invasion Ability of HeLa Cells.

    Science.gov (United States)

    Zhang, Ying-Hui; Wang, Juan-Juan; Li, Min; Zheng, Han-Xi; Xu, Lan; Chen, You-Guo

    2016-03-01

    The objectives of this study were to investigate the functional effect of matrix metallopeptidase 14 (MMP14) on cell invasion in cervical cancer cells (HeLa line) and to study the underlying molecular mechanisms. Expression vector of short hairpin RNA targeting MMP14 was treated in HeLa cells, and then, transfection efficiency was verified by a florescence microscope. Transwell assay was used to investigate cell invasion ability in HeLa cells. Quantitative polymerase chain reaction and Western blotting analysis were used to detect the expression of MMP14 and relative factors in messenger RNA and protein levels, respectively. Matrix metallopeptidase 14 short hairpin RNA expression vector transfection obviously decreased MMP14 expression in messenger RNA and protein levels. Down-regulation of MMP14 suppressed invasion ability of HeLa cells and reduced transforming growth factor β1 and vascular endothelial growth factor B expressions. Furthermore, MMP14 knockdown decreased bone sialoprotein and enhanced forkhead box protein L2 expression in both RNA and protein levels. Matrix metallopeptidase 14 plays an important role in regulating invasion of HeLa cells. Matrix metallopeptidase 14 knockdown contributes to attenuating the malignant phenotype of cervical cancer cell.

  6. Loss of a putative tumor suppressor locus after gamma-ray-induced neoplastic transformation of HeLa x Skin fibroblast human cell hybrids

    International Nuclear Information System (INIS)

    Mendonca, M.S.; Redpath, J.L.; Fasching, C.L.

    1995-01-01

    The nontumorigenic HeLa x skin fibroblast hybrid cell line, CGL1, can be induced to re-express HeLa tumor-associated cell surface antigen, p75-IAP (intestinal alkaline phosphatase), with resulting neoplastic transformation, by exposure to γ radiation. This has allowed the human hybrid system to be developed into a quantitative in vitro model for radiation-induced neoplastic transformation of human cells. Recently, several γ-ray-induced IAP-expression mutants (GIMs) of the nontumorigenic HeLa x skin fibroblast hybrid CGL1 were isolated and all were tumorigenic when injected subcutaneously into nude mice. Control cell lines which were negative for p75-IAP (CONs) were also isolated from irradiated populations, and none were found to be tumorigenic. We have now begun to investigate the molecular basis of radiation-induced neoplastic transformation in this system by studying the potential genetic linkage between p75/IAP expression, tumorigenicity and damage to a putative tumor suppressor locus on fibroblast chromosome 11. Previous analysis of rare spontaneous segregants has indicated that this locus is involved in the regulation of tumorigenicity and in the expression of the HeLa tumor-associated cell surface marker intestinal alkaline phosphatase (p75-IAP) in this system. Therefore, analysis by restriction fragment length polymorphism and chromosome painting have been performed for chromosome 11, and for chromosome 13 as a control, for the p75/IAP-positive GIM and p75/IAP-negative CON cell lines. We report that in five of eight of the GIMs large-scale damage to the fibroblast chromosome 11's is evident (four GIMs have lost one complete copy of a fibroblast chromosome 11 heavily damaged). None of the CONs, however (0/5), have lost a complete copy of either fibroblast chromosome 11. No large-scale damage to the control chromosome 13's was detected in the GIMs or CONs. 49 refs., 3 figs., 2 tabs

  7. T-DNA transfer and T-DNA integration efficiencies upon Arabidopsis thaliana root explant cocultivation and floral dip transformation.

    Science.gov (United States)

    Ghedira, Rim; De Buck, Sylvie; Van Ex, Frédéric; Angenon, Geert; Depicker, Ann

    2013-12-01

    T-DNA transfer and integration frequencies during Agrobacterium-mediated root explant cocultivation and floral dip transformations of Arabidopsis thaliana were analyzed with and without selection for transformation-competent cells. Based on the presence or absence of CRE recombinase activity without or with the CRE T-DNA being integrated, transient expression versus stable transformation was differentiated. During root explant cocultivation, continuous light enhanced the number of plant cells competent for interaction with Agrobacterium and thus the number of transient gene expression events. However, in transformation competent plant cells, continuous light did not further enhance cotransfer or cointegration frequencies. Upon selection for root transformants expressing a first T-DNA, 43-69 % of these transformants showed cotransfer of another non-selected T-DNA in two different light regimes. However, integration of the non-selected cotransferred T-DNA occurred only in 19-46 % of these transformants, indicating that T-DNA integration in regenerating root cells limits the transformation frequencies. After floral dip transformation, transient T-DNA expression without integration could not be detected, while stable T-DNA transformation occurred in 0.5-1.3 % of the T1 seedlings. Upon selection for floral dip transformants with a first T-DNA, 8-34 % of the transformants showed cotransfer of the other non-selected T-DNA and in 93-100 % of them, the T-DNA was also integrated. Therefore, a productive interaction between the agrobacteria and the female gametophyte, rather than the T-DNA integration process, restricts the floral dip transformation frequencies.

  8. [Physiological and biochemical analysis of the transformants of aerobic methylobacteria expressing the dcm A gene of dichloromethane dehydrogenase].

    Science.gov (United States)

    Firsova, Iu E; Doronina, N V; Trotsenko, Iu A

    2004-01-01

    The transformants of Methylobacterium dichloromethanicum DM4 (DM4-2cr-/pME8220 and DM4-2cr-/pME8221) and of Methylobacterium extorquens AM1 (AM1/pME8220 and AM1/pME8221) that express the dcm A gene of dichloromethane dehalogenase undergo lysis when incubated in the presence of dichloromethane and are sensitive to acidic shock. The lysis of the transformants was found to be related neither to the accumulation of Cl- ions, CH2O, and HCOOH, nor to the impairment of glutathione synthesis or to the maintenance of intracellular pH. The (exo-) Klenow fragment-mediated incorporation of [alpha-32P]dATP into the DNA of the transformants DM4-2cr-/pME8220 and AM1/pME8220 was considerably greater when the transformed cells were incubated with CH2Cl2 than when they were incubated with CH3OH, indicating the occurrence of a significant increase in the total length of gaps. At the same time, the strain AM1 (which lacks dichloromethane dehalogenase) and the dichloromethane-degrading strain DM4 incubated with CH2Cl2 showed an insignificant increase in the total length of the gaps. The transformed cells are likely to lyse due to the relatively inefficient repair of DNA lesions that are induced in response to the alkylating action of S-chloromethylglutathione, an intermediate product of CH2Cl2 degradation. The data obtained suggest that the bacterial mineralization of dichloromethane requires an efficient DNA repair system.

  9. Transformation of UV-hypersensitive Chinese hamster ovary cell mutants with UV-irradiated plasmids

    International Nuclear Information System (INIS)

    Nairn, R.S.; Humphrey, R.M.; Adair, G.M.

    1988-01-01

    Transfection of UV-hypersensitive, DNA repair-deficient Chinese hamster ovary (CHO) cell lines and parental, repair-proficient CHO cells with UV-irradiated pHaprt-1 or pSV2gpt plasmids resulted in different responses by recipient cell lines to UV damage in transfected DNA. Unlike results reported for human cells, UV irradiation of transfecting DNA did not stimulate genetic transformation of CHO recipient cells. In repair-deficient CHO cells, proportionally fewer transformants were produced with increasing UV damage than in repair-proficient cells in transfections with UV-irradiated hamster adenine phosphoribosyltransferase (APRT) gene contained in plasmid pHaprt-1. Transfection of CHO cells with UV-irradiated pSV2gpt resulted in neither decline in transformation frequencies in repair-deficient cell lines relative to repair-proficient cells nor stimulation of genetic transformation by UV damage in the plasmid. Blot hybridization analysis of DNA samples isolated from transformed cells showed no dramatic changes in copy number or arrangement of transfected plasmid DNA with increasing UV dose. The authors conclude responses of recipient cells to UV-damaged transfecting plasmids depend on type of recipient cell and characteristics of the genetic sequence used for transfection. (author)

  10. Development of an optimized tetracycline-inducible expression system to increase the accumulation of interleukin-10 in tobacco BY-2 suspension cells.

    Science.gov (United States)

    Bortesi, Luisa; Rademacher, Thomas; Schiermeyer, Andreas; Schuster, Flora; Pezzotti, Mario; Schillberg, Stefan

    2012-07-11

    Plant cell suspension cultures can be used for the production of valuable pharmaceutical and industrial proteins. When the recombinant protein is secreted into the culture medium, restricting expression to a defined growth phase can improve both the quality and quantity of the recovered product by minimizing proteolytic activity. Temporal restriction is also useful for recombinant proteins whose constitutive expression affects cell growth and viability, such as viral interleukin-10 (vIL-10). We have developed a novel, tetracycline-inducible system suitable for tobacco BY-2 suspension cells which increases the yields of vIL-10. The new system is based on a binary vector that is easier to handle than conventional vectors, contains an enhanced inducible promoter and 5'-UTR to improve yields, and incorporates a constitutively-expressed visible marker gene to allow the rapid and straightforward selection of the most promising transformed clones. Stable transformation of BY-2 cells with this vector, without extensive optimization of the induction conditions, led to a 3.5 fold increase in vIL-10 levels compared to constitutive expression in the same host. We have developed an effective and straightforward molecular farming platform technology that improves both the quality and the quantity of recombinant proteins produced in plant cells, particularly those whose constitutive expression has a negative impact on plant growth and development. Although we tested the platform using vIL-10 produced in BY-2 cells, it can be applied to other host/product combinations and is also useful for basic research requiring strictly controlled transgene expression.

  11. Cadmium-109 uptake by tumors derived from Balb C/3T3 cell lines with varying degrees of the transformed phenotype

    International Nuclear Information System (INIS)

    Morton, K.; Alazraki, N.; Winge, D.; Lynch, R.E.

    1986-01-01

    To determine if tumors are rich in metallothionein, the authors measured the vivo uptake of subcutaneously-injected carrier-free cadmium-109 in tumors and in normal tissues of Balb/C mice. The tumors were grown in the mice from cultured Balb/3T3 cells transformed by the Moloney murine sarcoma virus. Uptake of cadmium-109 per gram of tissue was greatest for liver, kidney, and spleen. However, tumor uptake of cadmium-109 was markedly greater than that in blood, skeletal muscle, bones, intestine or adipose tissue. B Sephadex G-75 chromatography, the radioactivity in tumor and in liver lysates eluted with cytochrome-C, a molecule similar in molecular weight to metal-lothionein. To determine if metallothionein levels are related to the degree of malignancy of tumors, cadmium-109 uptake in the tumors from the virally-transformed cells was compared to that in tumors from non-transformed Balb/3T3 cells and two derivative chemically transformed cell lines. There was strong correlation between the substrate-independent growth in soft agarose of the four cell lines, the rate of growth of the corresponding tumors, and the amount of cadmium-109 uptake in the tumors. The authors conclude that metallothionein levels may be elevated in tumors as a function of the degree of expression of the transformed phenotype

  12. Human trabecular meshwork cells express BMP antagonist mRNAs and proteins.

    Science.gov (United States)

    Tovar-Vidales, Tara; Fitzgerald, Ashley M; Clark, Abbot F

    2016-06-01

    Glaucoma patients have elevated aqueous humor and trabecular meshwork (TM) levels of transforming growth factor-beta2 (TGF-β2). TGF-β2 has been associated with increased extracellular matrix (ECM) deposition (i.e. fibronectin), which is attributed to the increased resistance of aqueous humor outflow through the TM. We have previously demonstrated that bone morphogenetic protein (BMP) 4 selectively counteracts the profibrotic effect of TGF-β2 with respect to ECM synthesis in the TM, and this action is reversed by the BMP antagonist gremlin. Thus, the BMP and TGF-β signaling pathways antagonize each other's antifibrotic and profibrotic roles. The purpose of this study was to determine whether cultured human TM cells: (a) express other BMP antagonists including noggin, chordin, BMPER, BAMBI, Smurf1 and 2, and (b) whether expression of these proteins is regulated by exogenous TGF-β2 treatment. Primary human trabecular meshwork (TM) cells were grown to confluency and treated with TGF-β2 (5 ng/ml) for 24 or 48 h in serum-free medium. Untreated cell served as controls. qPCR and Western immunoblots (WB) determined that human TM cells expressed mRNAs and proteins for the BMP antagonist proteins: noggin, chordin, BMPER, BAMBI, and Smurf1/2. Exogenous TGF-β2 decreased chordin, BMPER, BAMBI, and Smurf1 mRNA and protein expression. In contrast, TGF-β2 increased secreted noggin and Smurf2 mRNA and protein levels. BMP antagonist members are expressed in the human TM. These molecules may be involved in the normal function of the TM as well as TM pathogenesis. Altered expression of BMP antagonist members may lead to functional changes in the human TM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Neutron-energy-dependent cell survival and oncogenic transformation.

    Science.gov (United States)

    Miller, R C; Marino, S A; Martin, S G; Komatsu, K; Geard, C R; Brenner, D J; Hall, E J

    1999-12-01

    Both cell lethality and neoplastic transformation were assessed for C3H10T1/2 cells exposed to neutrons with energies from 0.040 to 13.7 MeV. Monoenergetic neutrons with energies from 0.23 to 13.7 MeV and two neutron energy spectra with average energies of 0.040 and 0.070 MeV were produced with a Van de Graaff accelerator at the Radiological Research Accelerator Facility (RARAF) in the Center for Radiological Research of Columbia University. For determination of relative biological effectiveness (RBE), cells were exposed to 250 kVp X rays. With exposures to 250 kVp X rays, both cell survival and radiation-induced oncogenic transformation were curvilinear. Irradiation of cells with neutrons at all energies resulted in linear responses as a function of dose for both biological endpoints. Results indicate a complex relationship between RBEm and neutron energy. For both survival and transformation, RBEm was greatest for cells exposed to 0.35 MeV neutrons. RBEm was significantly less at energies above or below 0.35 MeV. These results are consistent with microdosimetric expectation. These results are also compatible with current assessments of neutron radiation weighting factors for radiation protection purposes. Based on calculations of dose-averaged LET, 0.35 MeV neutrons have the greatest LET and therefore would be expected to be more biologically effective than neutrons of greater or lesser energies.

  14. ALDH1 and podoplanin expression patterns predict the risk of malignant transformation in oral leukoplakia.

    Science.gov (United States)

    Habiba, Umma; Hida, Kyoko; Kitamura, Tetsuya; Matsuda, Aya Yanagawa; Higashino, Fumihiro; Ito, Yoichi M; Ohiro, Yoichi; Totsuka, Yasunori; Shindoh, Masanobu

    2017-01-01

    Oral leukoplakia (OL) is a clinically diagnosed preneoplastic lesion of the oral cavity with an increased oral cancer risk. However, the risk of malignant transformation is still difficult to assess. The objective of the present study was to examine the expression patterns of aldehyde dehydrogenase 1 (ALDH1) and podoplanin in OL, and to determine their roles in predicting oral cancer development. In the present study, the expression patterns of ALDH1 and podoplanin were determined in samples from 79 patients with OL. The association between protein expression and clinicopathological parameters, including oral cancer-free survival, was analyzed during a mean follow-up period of 3.4 years. Expression of ALDH1 and podoplanin was observed in 61 and 67% patients, respectively. Kaplan-Meier analysis demonstrated that the expression of the proteins was correlated with the risk of progression to oral cancer. Multivariate analysis revealed that expression of ALDH1 and podoplanin was associated with 3.02- and 2.62-fold increased risk of malignant transformation, respectively. The malignant transformation risk of OL was considerably higher in cases with expression of both proteins. Point-prevalence analysis revealed that 66% of patients with co-expression of ALDH1 and podoplanin developed oral cancer. Taken together, our data indicate that ALDH1 and podoplanin expression patterns in OL are associated with oral cancer development, suggesting that ALDH1 and podoplanin may be useful biomarkers to identify OL patients with a substantially high oral cancer risk.

  15. Misoprostol-induced radioprotection of Syrian hamster embryo cells in utero from cell death and oncogenic transformation

    International Nuclear Information System (INIS)

    Miller, R.C.; LaNasa, P.; Hanson, W.R.

    1994-01-01

    Misoprostol, a PGE analog, is an effective radioprotector of murine intestine and hematopoietic and hair cell renewal systems. The radioprotective nature of misoprostol was extended to examine its ability to influence clonogenic cell survival and induction of oncogenic transformation in Syrian hamster embryo cells exposed to X rays in utero and assayed in vitro. Hamsters in their 12th day of pregnancy were injected subcutaneously with misoprostal, and 2 h later the pregnant hamsters were exposed to graded doses of X rays. Immediately after irradiation, hamsters were euthanized and embryonic tissue was explanted into culture dishes containing complete growth medium. After a 2-week incubation period, clongenic cell survival and morphologically transformed foci were determined. Survival of misoprostol-treated SHE cells was increased and yielded a dose reduction factor of 1.5 compared to SHE cells treated with X rays alone. In contrast, radiation-induced oncogenic transformation of misoprostol-treated cells was reduced by a factor of 20 compared to cells treated with X rays alone. These studies suggest that misoprostol not only protects normal tissues in vivo from acute radiation injury, but also protects cells, to a large extent, from injury leading to transforming events. 26 refs., 6 figs., 2 tabs

  16. Loss of RUNX3 expression inhibits bone invasion of oral squamous cell carcinoma.

    Science.gov (United States)

    Park, Junhee; Kim, Hyun-Jeong; Kim, Ki Rim; Lee, Sun Kyoung; Kim, Hyungkeun; Park, Kwang-Kyun; Chung, Won-Yoon

    2017-02-07

    High recurrence and lower survival rates in patients with oral squamous cell carcinoma (OSCC) are associated with its bone invasion. We identified the oncogenic role of RUNX3 during bone invasion by OSCC. Tumor growth and the generation of osteolytic lesions were significantly inhibited in mice that were subcutaneously inoculated with RUNX3-knockdown human OSCC cells. RUNX3 knockdown enhanced TGF-β-induced growth arrest and inhibited OSCC cell migration and invasion in the absence or presence of transforming growth factor-β (TGF-β), a major growth factor abundant in the bone microenvironment. RUNX3 knockdown induced cell cycle arrest at the G1 and G2 phases and promoted G2 arrest by TGF-β in Ca9.22 OSCC cells. RUNX3 knockdown also inhibited both the basal and TGF-β-induced epithelial-to-mesenchymal transition by increasing E-cadherin expression and suppressing the nuclear translocation of β-catenin. In addition, the expression and TGF-β-mediated induction of parathyroid hormone-related protein (PTHrP), one of key osteolytic factors, was blocked in RUNX3-knockdown OSCC cells. Furthermore, treating human osteoblastic cells with conditioned medium derived from RUNX3-knockdown OSCC cells reduced the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin ratio compared with treatment with conditioned medium from RUNX3-expressing cells. These findings indicate that RUNX3 expression in OSCC cells contributes to their bone invasion and the resulting osteolysis by inducing their malignant behaviors and production of osteolytic factors. RUNX3 alone or in combination with TGF-β and PTHrP may be a useful predictive biomarker and therapeutic target for bone invasion by oral cancer.

  17. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    International Nuclear Information System (INIS)

    Stueckle, Todd A.; Lu, Yongju; Davis, Mary E.; Wang, Liying; Jiang, Bing-Hua; Holaskova, Ida; Schafer, Rosana; Barnett, John B.; Rojanasakul, Yon

    2012-01-01

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As 2 O 3

  18. Chronic occupational exposure to arsenic induces carcinogenic gene signaling networks and neoplastic transformation in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Stueckle, Todd A., E-mail: tstueckle@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Lu, Yongju, E-mail: yongju6@hotmail.com [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States); Davis, Mary E., E-mail: mdavis@wvu.edu [Department of Physiology, West Virginia University, Morgantown, WV 26506 (United States); Wang, Liying, E-mail: lmw6@cdc.gov [Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, WV 26505 (United States); Jiang, Bing-Hua, E-mail: bhjiang@jefferson.edu [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Holaskova, Ida, E-mail: iholaskova@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Schafer, Rosana, E-mail: rschafer@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Barnett, John B., E-mail: jbarnett@hsc.wvu.edu [Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV 26506 (United States); Rojanasakul, Yon, E-mail: yrojan@hsc.wvu.edu [Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26506 (United States)

    2012-06-01

    Chronic arsenic exposure remains a human health risk; however a clear mode of action to understand gene signaling-driven arsenic carcinogenesis is currently lacking. This study chronically exposed human lung epithelial BEAS-2B cells to low-dose arsenic trioxide to elucidate cancer promoting gene signaling networks associated with arsenic-transformed (B-As) cells. Following a 6 month exposure, exposed cells were assessed for enhanced cell proliferation, colony formation, invasion ability and in vivo tumor formation compared to control cell lines. Collected mRNA was subjected to whole genome expression microarray profiling followed by in silico Ingenuity Pathway Analysis (IPA) to identify lung carcinogenesis modes of action. B-As cells displayed significant increases in proliferation, colony formation and invasion ability compared to BEAS-2B cells. B-As injections into nude mice resulted in development of primary and secondary metastatic tumors. Arsenic exposure resulted in widespread up-regulation of genes associated with mitochondrial metabolism and increased reactive oxygen species protection suggesting mitochondrial dysfunction. Carcinogenic initiation via reactive oxygen species and epigenetic mechanisms was further supported by altered DNA repair, histone, and ROS-sensitive signaling. NF-κB, MAPK and NCOR1 signaling disrupted PPARα/δ-mediated lipid homeostasis. A ‘pro-cancer’ gene signaling network identified increased survival, proliferation, inflammation, metabolism, anti-apoptosis and mobility signaling. IPA-ranked signaling networks identified altered p21, EF1α, Akt, MAPK, and NF-κB signaling networks promoting genetic disorder, altered cell cycle, cancer and changes in nucleic acid and energy metabolism. In conclusion, transformed B-As cells with their whole genome expression profile provide an in vitro arsenic model for future lung cancer signaling research and data for chronic arsenic exposure risk assessment. Highlights: ► Chronic As{sub 2}O

  19. E6D25E, HPV16 Asian variant shows specific proteomic pattern correlating in cells transformation and suppressive innate immune response

    International Nuclear Information System (INIS)

    Chopjitt, Peechanika; Pientong, Chamsai; Sunthamala, Nuchsupha; Kongyingyoes, Bunkerd; Haonon, Ornuma; Boonmars, Thidarut; Kikawa, Satomi; Nakahara, Tomomi; Kiyono, Tohru; Ekalaksananan, Tipaya

    2016-01-01

    HPV16 Asian variant (HPV16As) containing E6D25E oncogene, is commonly associated with cervical cancers of Asian populations. To explore a mechanism of E6D25E oncoprotein in carcinogenesis, we compared protein profiles in human keratinocytes expressing E6D25E with E6 of HPV16 prototype (E6Pro). A human cervical keratinocyte cell line, HCK1T, was transduced with retroviruses containing E6D25E or E6Pro genes. Biological properties of E6D25E or E6Pro transduced HCK1T cells were characterized. Protein profiles of the transduced HCK1T cells were analyzed using 2D-PAGE and characterized by mass spectrometry and western blotting. Reactomes of modulated proteins were analyzed by using the Reactome Knowledgebase. The E6D25E and E6Pro oncoproteins were comparable for their abilities to degrade p53 and suppress the induction of p21, and induce cell proliferation. Interestingly, the protein profiles of the HCK1T cells transduced with E6D25E showed specific proteomic patterns different from those with E6Pro. Among altered proteins, more than 1.5-fold up- or down- regulation was observed in E6D25E-expressing cells for gp96 and keratin7 which involved in activation of TLR signaling and transformation of squamocolumnar junction cells, respectively. This report describes new cellular proteins specifically targeted by E6D25E oncoprotein that may contribute to impair immune response against viral infection and cell transformation associated with oncogenic property of HPV16As variant. - Highlights: • E6D25E HPV16 specifically modulates protein profile of human keratinocytes. • E6D25E HPV16 modulates protein profile which involves in TLR signalling and transformation of squamocolumnar junction cells. • E6D25E oncoprotein may correlate to impair of immune response against viral infection and cells transformation.

  20. E6D25E, HPV16 Asian variant shows specific proteomic pattern correlating in cells transformation and suppressive innate immune response

    Energy Technology Data Exchange (ETDEWEB)

    Chopjitt, Peechanika; Pientong, Chamsai; Sunthamala, Nuchsupha [Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002 (Thailand); HPV & EBV and Carcinogenesis Research Group, Khon Kaen University (Thailand); Kongyingyoes, Bunkerd [Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002 (Thailand); Haonon, Ornuma; Boonmars, Thidarut [Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002 (Thailand); Kikawa, Satomi; Nakahara, Tomomi [Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 (Japan); Kiyono, Tohru, E-mail: tkiyono@ncc.go.jp [Division of Carcinogenesis and Cancer Prevention, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045 (Japan); Ekalaksananan, Tipaya, E-mail: tipeka@kku.ac.th [Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002 (Thailand); HPV & EBV and Carcinogenesis Research Group, Khon Kaen University (Thailand)

    2016-09-09

    HPV16 Asian variant (HPV16As) containing E6D25E oncogene, is commonly associated with cervical cancers of Asian populations. To explore a mechanism of E6D25E oncoprotein in carcinogenesis, we compared protein profiles in human keratinocytes expressing E6D25E with E6 of HPV16 prototype (E6Pro). A human cervical keratinocyte cell line, HCK1T, was transduced with retroviruses containing E6D25E or E6Pro genes. Biological properties of E6D25E or E6Pro transduced HCK1T cells were characterized. Protein profiles of the transduced HCK1T cells were analyzed using 2D-PAGE and characterized by mass spectrometry and western blotting. Reactomes of modulated proteins were analyzed by using the Reactome Knowledgebase. The E6D25E and E6Pro oncoproteins were comparable for their abilities to degrade p53 and suppress the induction of p21, and induce cell proliferation. Interestingly, the protein profiles of the HCK1T cells transduced with E6D25E showed specific proteomic patterns different from those with E6Pro. Among altered proteins, more than 1.5-fold up- or down- regulation was observed in E6D25E-expressing cells for gp96 and keratin7 which involved in activation of TLR signaling and transformation of squamocolumnar junction cells, respectively. This report describes new cellular proteins specifically targeted by E6D25E oncoprotein that may contribute to impair immune response against viral infection and cell transformation associated with oncogenic property of HPV16As variant. - Highlights: • E6D25E HPV16 specifically modulates protein profile of human keratinocytes. • E6D25E HPV16 modulates protein profile which involves in TLR signalling and transformation of squamocolumnar junction cells. • E6D25E oncoprotein may correlate to impair of immune response against viral infection and cells transformation.

  1. miR-208-3p promotes hepatocellular carcinoma cell proliferation and invasion through regulating ARID2 expression

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Peng; Wu, Dingguo; You, Yu; Sun, Jing; Lu, Lele; Tan, Jiaxing; Bie, Ping, E-mail: bieping2010@163.com

    2015-08-15

    MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at post-transcriptional level. miRNA dysregulation plays a causal role in cancer progression. In this study, miR-208-3p was highly expressed and directly repressed ARID2 expression. As a result, ARID2 expression in hepatocellular carcinoma (HCC) was decreased. In vitro, miR-208-3p down-regulation and ARID2 over-expression elicited similar inhibitory effects on HCC cell proliferation and invasion. In vivo test results revealed that miR-208-3p down-regulation inhibited HCC tumorigenesis in Hep3B cells. Moreover, ARID2 was possibly a downstream element of transforming growth factor beta1 (TGFβ1)/miR-208-3p/ARID2 regulatory pathway. These findings suggested that miR-208-3p up-regulation is associated with HCC cell progression and may provide a new target for liver cancer treatment. - Highlights: • miR-208-3p was highly expressed and directly repressed the expression of ARID2 in HCC. • miR-208-3p contributed to HCC cell progression both in vitro and in vivo. • Over-expression of ARID2 inhibited the HCC cell proliferation and invasion. • Restoration of ARID2 partly reversed the the effect of miR-208-3p down-regulation on HCC cells. • Newly regulatory pathway: miR-208-3p mediated the repression of ARID2 by TGFβ1 in HCC cells.

  2. Possible involvement of MSX-2 homeoprotein in v-ras-induced transformation.

    Science.gov (United States)

    Takahashi, C; Akiyama, N; Kitayama, H; Takai, S; Noda, M

    1997-04-01

    A truncated MSX-2 homeoprotein was found to induce flat reversion when expressed in v-Ki-ras-transformed NIH3T3 cells. Although the expression of endogenous MSX-2 gene is low in most of the normal adult tissues examined, it is frequently activated in carcinoma-derived cell lines. Likewise, the gene is inactive in untransformed cells but is transcriptionally activated after transformation by v-Ki-ras oncogene, suggesting that the intact MSX-2 may play a positive, rather than suppressive, role in cell transformation. To test this possibility, we isolated a full-length human MSX-2 cDNA and tested its activities in two cell systems: fibroblast and myoblast. In NIH3T3 fibroblasts, although the gene by itself failed to confer a transformed phenotype, antisense MSX-2 cDNA as well as truncated MSX-2 cDNA interfered with the transforming activities of both v-Ki-ras and v-raf oncogene. In C2C12 myoblasts, MSX-2 was found to suppress MyoD gene expression, as do activated ras oncogenes, under certain culture conditions, and truncated MSX-2 cDNA was found to inhibit the activities of both MSX-2 and ras in this system as well. Our findings not only suggest that the truncated version MSX-2 may act as a dominant suppressor of intact MSX-2 but also raise the possibility that MSX-2 gene may be an important downstream target for the Ras signaling pathways.

  3. Isolation and characterization of NIH 3T3 cells expressing polyomavirus small T antigen

    International Nuclear Information System (INIS)

    Noda, T.; Satake, M.; Robins, T.; Ito, Y.

    1986-01-01

    The polyomavirus small T-antigen gene, together with the polyomavirus promoter, was inserted into retrovirus vector pGV16 which contains the Moloney sarcoma virus long terminal repeat and neomycin resistance gene driven by the simian virus 40 promoter. This expression vector, pGVST, was packaged into retrovirus particles by transfection of PSI2 cells which harbor packaging-defective murine retrovirus genome. NIH 3T3 cells were infected by this replication-defective retrovirus containing pGVST. Of the 15 G418-resistant cell clones, 8 express small T antigen at various levels as revealed by immunoprecipitation. A cellular protein with an apparent molecular weight of about 32,000 coprecipitates with small T antigen. Immunofluorescent staining shows that small T antigen is mainly present in the nuclei. Morphologically, cells expressing small T antigen are indistinguishable from parental NIH 3T3 cells and have a microfilament pattern similar to that in parental NIH 3T3 cells. Cells expressing small T antigen form a flat monolayer but continue to grow beyond the saturation density observed for parental NIH 3T3 cells and eventually come off the culture plate as a result of overconfluency. There is some correlation between the level of expression of small T antigen and the growth rate of the cells. Small T-antigen-expressing cells form small colonies in soft agar. However, the proportion of cells which form these small colonies is rather small. A clone of these cells tested did not form tumors in nude mice within 3 months after inoculation of 10 6 cells per animal. Thus, present studies establish that the small T antigen of polyomavirus is a second nucleus-localized transforming gene product of the virus (the first one being large T antigen) and by itself has a function which is to stimulate the growth of NIH 3T3 cells beyond their saturation density in monolayer culture

  4. Specification of fast neutron radiation quality from cell transformation data

    International Nuclear Information System (INIS)

    Coppola, M.

    1992-01-01

    Experimental data on the neoplastic transformation of C3H 10T1/2 cells measured at Casaccia after neutron and X-ray irradiation were used to determine neutron RBE values for the RSV-Tapiro fast reactor energy spectrum and for monoenergetic neutrons of 0.5, 1, and 6 MeV. In parallel, micro-dosimetric measurements provided the actual lineal energy distributions and related mean parameters for the reactor radiation. From these experiments, values of the neutron quality factor were derived for the reactor neutron energy spectrum and, in turn, for the other neutron energies tested. A mathematical expression giving a smooth dependence on neutron energy was also determined for the effective quality factor in the entire energy range examined. The results were compared with other proposals

  5. Involvement of aberrant DNA methylation on reduced expression of lysophosphatidic acid receptor-1 gene in rat tumor cell lines

    International Nuclear Information System (INIS)

    Tsujiuchi, Toshifumi; Shimizu, Kyoko; Onishi, Mariko; Sugata, Eriko; Fujii, Hiromasa; Mori, Toshio; Honoki, Kanya; Fukushima, Nobuyuki

    2006-01-01

    Lysophosphatidic acid (LPA) is a bioactive phospholipid that stimulates cell proliferation, migration, and protects cells from apoptosis. It interacts with specific G protein-coupled transmembrane receptors. Recently, it has been reported that alterations of LPA receptor expression might be important in the malignant transformation of tumor cells. Therefore, to assess an involvement of DNA methylation in reduced expression of the LPA receptor-1 (lpa1) gene, we investigated the expression of the lpa1 gene and its DNA methylation patterns in rat tumor cell lines. Both rat brain-derived neuroblastoma B103 and liver-derived hepatoma RH7777 cells used in this study indicated no expression of lpa1. For the analysis of methylation status, bisulfite sequencing was performed with B103 and RH7777 cells, comparing with other lpa1 expressed cells and normal tissues of brain and liver. The lpa1 expressed cells and tissues were all unmethylated in this region of lpa1. In contrast, both B103 and RH7777 cells were highly methylated, correlating with reduced expression of the lpa1. Treatment with 5-aza 2'-deoxycytidine induced expression of lpa1 gene in B103 and RH7777 cells after 24 h. In RH7777 cells treated with 5-aza 2'-deoxycytidine, stress fiber formation was also observed in response to LPA in RH7777 cells, but not in untreated RH7777 cells. These results suggest that aberrant DNA methylation of the lpa1 gene may be involved in its reduced expression in rat tumor cells

  6. Expression of heparanase in basal cell carcinoma and squamous cell carcinoma.

    Science.gov (United States)

    Pinhal, Maria Aparecida Silva; Almeida, Maria Carolina Leal; Costa, Alessandra Scorse; Theodoro, Thérèse Rachell; Serrano, Rodrigo Lorenzetti; Machado, Carlos D'Apparecida Santos

    2016-01-01

    Heparanase is an enzyme that cleaves heparan sulfate chains. Oligosaccharides generated by heparanase induce tumor progression. Basal cell carcinoma and squamous cell carcinoma comprise types of nonmelanoma skin cancer. Evaluate the glycosaminoglycans profile and expression of heparanase in two human cell lines established in culture, immortalized skin keratinocyte (HaCaT) and squamous cell carcinoma (A431) and also investigate the expression of heparanase in basal cell carcinoma, squamous cell carcinoma and eyelid skin of individuals not affected by the disease (control). Glycosaminoglycans were quantified by electrophoresis and indirect ELISA method. The heparanase expression was analyzed by quantitative RT-PCR (qRTPCR). The A431 strain showed significant increase in the sulfated glycosaminoglycans, increased heparanase expression and decreased hyaluronic acid, comparing to the HaCaT lineage. The mRNA expression of heparanase was significantly higher in Basal cell carcinoma and squamous cell carcinoma compared with control skin samples. It was also observed increased heparanase expression in squamous cell carcinoma compared to the Basal cell carcinoma. The glycosaminoglycans profile, as well as heparanase expression are different between HaCaT and A431 cell lines. The increased expression of heparanase in Basal cell carcinoma and squamous cell carcinoma suggests that this enzyme could be a marker for the diagnosis of such types of non-melanoma cancers, and may be useful as a target molecule for future alternative treatment.

  7. A novel approach for in vitro studies applying electrical fields to cell cultures by transformer-like coupling.

    Science.gov (United States)

    Hess, R; Neubert, H; Seifert, A; Bierbaum, S; Hart, D A; Scharnweber, D

    2012-12-01

    The purpose of this study was to develop a new apparatus for in vitro studies applying low frequency electrical fields to cells without interfering side effects like biochemical reactions or magnetic fields which occur in currently available systems. We developed a non-invasive method by means of the principle of transformer-like coupling where the magnetic field is concentrated in a toroid and, therefore, does not affect the cell culture. Next to an extensive characterization of the electrical field parameters, initial cell culture studies have focused on examining the response of bone marrow-derived human mesenchymal stem cells (MSCs) to pulsed electrical fields. While no significant differences in the proliferation of human MSCs could be detected, significant increases in ALP activity as well as in gene expression of other osteogenic markers were observed. The results indicate that transformer-like coupled electrical fields can be used to influence osteogenic differentiation of human MSCs in vitro and can pose a useful tool in understanding the influence of electrical fields on the cellular and molecular level.

  8. Cellular transformation by radiation: induction, promotion, and inhibition

    International Nuclear Information System (INIS)

    Borek, C.

    1981-01-01

    Radiation oncogenesis induced in utero in hamsters is expressed at a lower frequency than that induced in vitro. Quantitative studies carried out on hamster embryo cells indicate that neutrons are more effective in their carcinogenic potential than x-rays but also more toxic, that splitting the dose of x-rays at low doses leads to enhanced transformation, but that at high doses protracted radiation has a sparing effect. At all dose ranges survival was increased by protracting the radiation dose, thus suggesting that different repair processes must be involved for survival and transformation. In our qualitative studies, once cells are transformed by radiation, they exhibit a wide range of structural and functional phenotypic changes, some of which are membrane-associated and are expressed within days after induction. Our current studies on nutritional and hormonal influences on radiation transformation indicate the following: Pyrolysate products from broiled protein foods act in synergism with radiation to produce transformation, whereas vitamin A analogs are powerful, preventive agents. Retinoids inhibit both x-ray-induced transformation and its promotion by TPA; these modifications (enhancement by TPA, inhibition by retinoids) are not reflected in sister chromatid exchanges, but are reflected in the level of membrane associated enzymes Na/K ATPase. Whereas retinoids modify late events (expression, promotion), we find that thyroid hormone plays a crucial role in the early phases of radiation and chemically induced transformation. Our recent success in transforming human skin fibroblasts will enable quantitative and qualitative studies of radiation carcinogenesis in a system relevant to man

  9. UV stimulation of DNA-mediated transformation of human cells

    International Nuclear Information System (INIS)

    van Duin, M.; Westerveld, A.; Hoeijmakers, J.H.

    1985-01-01

    Irradiation of dominant marker DNA with UV light (150 to 1,000 J/m2) was found to stimulate the transformation of human cells by this marker from two- to more than fourfold. This phenomenon is also displayed by xeroderma pigmentosum cells, which are deficient in the excision repair of UV-induced pyrimidine dimers in the DNA. Also, exposure to UV of the transfected (xeroderma pigmentosum) cells enhanced the transfection efficiency. Removal of the pyrimidine dimers from the DNA by photoreactivating enzyme before transfection completely abolished the stimulatory effect, indicating that dimer lesions are mainly responsible for the observed enhancement. A similar stimulation of the transformation efficiency is exerted by 2-acetoxy-2-acetylaminofluorene modification of the DNA. These findings suggest that lesions which are targets for the excision repair pathway induce the increase in transformation frequency. The stimulation was found to be independent of sequence homology between the irradiated DNA and the host chromosomal DNA. Therefore, the increase of the transformation frequency is not caused by a mechanism inducing homologous recombination between these two DNAs. UV treatment of DNA before transfection did not have a significant effect on the amount of DNA integrated into the xeroderma pigmentosum genome

  10. The Role of Titanium Surface Microtopography on Adhesion, Proliferation, Transformation, and Matrix Deposition of Corneal Cells.

    Science.gov (United States)

    Zhou, Chengxin; Lei, Fengyang; Chodosh, James; Paschalis, Eleftherios I

    2016-04-01

    Titanium (Ti) is an excellent implantable biomaterial that can be further enhanced by surface topography optimization. Despite numerous data from orthopedics and dentistry, the effect of Ti surface topography on ocular cells is still poorly understood. In light of the recent adaptation of Ti in the Boston Keratoprosthesis artificial cornea, we attempted to perform an extended evaluation of the effect of Ti surface topography on corneal cell adhesion, proliferation, cytotoxicity, transformation, and matrix deposition. Different surface topographies were generated on medical grade Ti-6Al-4V-ELI (extra-low interstitial), with linearly increased roughness (polished to grit blasted). Biological response was evaluated in vitro using human corneal limbal epithelial (HCLE) cells, stromal fibroblasts (HCF), and endothelial cells (HCEnC). None of the Ti surface topographies caused cytotoxicity to any of the three corneal cell types. However, rough Ti surface inhibited HCLE and HCF cell adhesion and proliferation, while HCEnC proliferation was unaffected. Long-term experiments with HCF revealed that rough Ti surface with R(a) (the arithmetic average of the profile height from the mean line) ≥ 1.15 μm suppressed HCF focal adhesion kinase phosphorylation, changed fibroblast morphology, and caused less aligned and reduced deposition of collagen matrix as compared to smooth Ti (R(a) ≤ 0.08 μm). In the presence of transforming growth factor β1 (TGFβ1) stimulation, rough Ti inhibited alpha-smooth muscle actin (α-SMA) expression and collagen deposition, leading to decreased myofibroblast transformation and disorganization of the collagen fibrils as compared to smooth Ti. This study suggests that Ti surface topography regulates corneal cell behavior in a tissue-dependent manner that varies across the corneal strata. Contrary to the accepted paradigm, smooth surface topography can enhance cell adhesion and proliferation and increase matrix deposition by corneal cells.

  11. In vitro cell transformation induced by synthetic amorphous silica nanoparticles.

    Science.gov (United States)

    Fontana, Caroline; Kirsch, Anaïs; Seidel, Carole; Marpeaux, Léa; Darne, Christian; Gaté, Laurent; Remy, Aurélie; Guichard, Yves

    2017-11-01

    Synthetic amorphous silica nanoparticles (SAS) are among the most widely produced and used nanomaterials, but little is known about their carcinogenic potential. This study aims to evaluate the ability of four different SAS, two precipitated, NM-200 and NM-201, and two pyrogenic, NM-202 and NM-203, to induce the transformation process. For this, we used the recently developed in vitro Bhas 42 cell transformation assay (CTA). The genome of the transgenic Bhas 42 cells contains several copies of the v-Ha-ras gene, making them particularly sensitive to tumor-promoter agents. The Bhas 42 CTA, which includes an initiation assay and a promotion assay, was validated in our laboratory using known soluble carcinogenic substances. Its suitability for particle-type substances was verified by using quartz Min-U-Sil 5 (Min-U-Sil) and diatomaceous earth (DE) microparticles. As expected given their known transforming properties, Min-U-Sil responded positively in the Bhas 42 CTA and DE responded negatively. Transformation assays were performed with SAS at concentrations ranging from 2μg/cm 2 to 80μg/cm 2 . Results showed that all SAS have the capacity to induce transformed foci, interestingly only in the promotion assay, suggesting a mode of action similar to tumor-promoter substances. NM-203 exhibited transforming activity at a lower concentration than the other SAS. In conclusion, this study showed for the first time the transforming potential of different SAS, which act as tumor-promoter substances in the Bhas 42 model of cell transformation. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Transformation of mouse embryo (C3H 10T1/2) cells by alpha particles

    International Nuclear Information System (INIS)

    Lloyd, E.L.; Gemmell, A.; Henning, C.B.; Gemmell, D.S.; Zabransky, B.J.

    1977-01-01

    Mammalian cells in culture (C3H mouse 10T1/2 cells) have been shown here for the first time to be transformed by alpha irradiation when cells were irradiated with 5.6 MeV alpha particles from a Tandem Van de Graaff machine. Malignant tumors were induced following inoculation of the transformed cells into syngeneic hosts. Unirradiated control cells injected at the same concentration have, so far, failed to produce tumors. The morphology of the transformed foci was remarkably similar to that obtained by x rays and chemicals but different from virally transformed cells. When the cells were seeded at low density in the exponential growth phase, the transformation frequency per surviving cell increased approximately as the cube of the dose and peaked at an alpha particle fluence between 1.5 and 2.5 x 10 7 alpha particles per cm 2 (205 to 342 rads). The frequency of the transformation was found to be greatly dependent on the number of cells per dish irradiated. Irradiation of larger numbers resulted in much lower frequencies of transformation. The maximum transformation frequency observed in nine separate experiments was 4 percent of the surviving cells. At doses greater than 200 rads the transformation frequency per surviving cell remained constant. The present results permit us to conclude that alpha irradiation may, indeed, be able to exert a direct effect on the genome of the cell to produce malignancy without any external immunological or hormonal influences

  13. Aurora-A overexpression enhances cell-aggregation of Ha-ras transformants through the MEK/ERK signaling pathway

    International Nuclear Information System (INIS)

    Tseng, Ya-Shih; Lee, Jenq-Chang; Huang, Chi-Ying F; Liu, Hsiao-Sheng

    2009-01-01

    Overexpression of Aurora-A and mutant Ras (Ras V12 ) together has been detected in human bladder cancer tissue. However, it is not clear whether this phenomenon is a general event or not. Although crosstalk between Aurora-A and Ras signaling pathways has been reported, the role of these two genes acting together in tumorigenesis remains unclear. Real-time PCR and sequence analysis were utilized to identify Ha- and Ki-ras mutation (Gly -> Val). Immunohistochemistry staining was used to measure the level of Aurora-A expression in bladder and colon cancer specimens. To reveal the effect of overexpression of the above two genes on cellular responses, mouse NIH3T3 fibroblast derived cell lines over-expressing either Ras V12 and wild-type Aurora-A (designated WT) or Ras V12 and kinase-inactivated Aurora-A (KD) were established. MTT and focus formation assays were conducted to measure proliferation rate and focus formation capability of the cells. Small interfering RNA, pharmacological inhibitors and dominant negative genes were used to dissect the signaling pathways involved. Overexpression of wild-type Aurora-A and mutation of Ras V12 were detected in human bladder and colon cancer tissues. Wild-type Aurora-A induces focus formation and aggregation of the Ras V12 transformants. Aurora-A activates Ral A and the phosphorylation of AKT as well as enhances the phosphorylation of MEK, ERK of WT cells. Finally, the Ras/MEK/ERK signaling pathway is responsible for Aurora-A induced aggregation of the Ras V12 transformants. Wild-type-Aurora-A enhances focus formation and aggregation of the Ras V12 transformants and the latter occurs through modulating the Ras/MEK/ERK signaling pathway

  14. Genetic transformation of an obligate anaerobe, P. gingivalis for FMN-green fluorescent protein expression in studying host-microbe interaction.

    Directory of Open Access Journals (Sweden)

    Chul Hee Choi

    Full Text Available The recent introduction of "oxygen-independent" flavin mononucleotide (FMN-based fluorescent proteins (FbFPs is of major interest to both eukaryotic and prokaryotic microbial biologists. Accordingly, we demonstrate for the first time that an obligate anaerobe, the successful opportunistic pathogen of the oral cavity, Porphyromonas gingivalis, can be genetically engineered for expression of the non-toxic green FbFP. The resulting transformants are functional for studying dynamic bacterial processes in living host cells. The visualization of the transformed P. gingivalis (PgFbFP revealed strong fluorescence that reached a maximum emission at 495 nm as determined by fluorescence microscopy and spectrofluorometry. Human primary gingival epithelial cells (GECs were infected with PgFbFP and the bacterial invasion of host cells was analyzed by a quantitative fluorescence microscopy and antibiotic protection assays. The results showed similar levels of intracellular bacteria for both wild type and PgFbFP strains. In conjunction with organelle specific fluorescent dyes, utilization of the transformed strain provided direct and accurate determination of the live/metabolically active P. gingivalis' trafficking in the GECs over time. Furthermore, the GECs were co-infected with PgFbFP and the ATP-dependent Clp serine protease-deficient mutant (ClpP- to study the differential fates of the two strains within the same host cells. Quantitative co-localization analyses displayed the intracellular PgFbFP significantly associated with the endoplasmic reticulum network, whereas the majority of ClpP- organisms trafficked into the lysosomes. Hence, we have developed a novel and reliable method to characterize live host cell-microbe interactions and demonstrated the adaptability of FMN-green fluorescent protein for studying persistent host infections induced by obligate anaerobic organisms.

  15. Genetic transformation of an obligate anaerobe, P. gingivalis for FMN-green fluorescent protein expression in studying host-microbe interaction.

    Science.gov (United States)

    Choi, Chul Hee; DeGuzman, Jefferson V; Lamont, Richard J; Yilmaz, Özlem

    2011-04-15

    The recent introduction of "oxygen-independent" flavin mononucleotide (FMN)-based fluorescent proteins (FbFPs) is of major interest to both eukaryotic and prokaryotic microbial biologists. Accordingly, we demonstrate for the first time that an obligate anaerobe, the successful opportunistic pathogen of the oral cavity, Porphyromonas gingivalis, can be genetically engineered for expression of the non-toxic green FbFP. The resulting transformants are functional for studying dynamic bacterial processes in living host cells. The visualization of the transformed P. gingivalis (PgFbFP) revealed strong fluorescence that reached a maximum emission at 495 nm as determined by fluorescence microscopy and spectrofluorometry. Human primary gingival epithelial cells (GECs) were infected with PgFbFP and the bacterial invasion of host cells was analyzed by a quantitative fluorescence microscopy and antibiotic protection assays. The results showed similar levels of intracellular bacteria for both wild type and PgFbFP strains. In conjunction with organelle specific fluorescent dyes, utilization of the transformed strain provided direct and accurate determination of the live/metabolically active P. gingivalis' trafficking in the GECs over time. Furthermore, the GECs were co-infected with PgFbFP and the ATP-dependent Clp serine protease-deficient mutant (ClpP-) to study the differential fates of the two strains within the same host cells. Quantitative co-localization analyses displayed the intracellular PgFbFP significantly associated with the endoplasmic reticulum network, whereas the majority of ClpP- organisms trafficked into the lysosomes. Hence, we have developed a novel and reliable method to characterize live host cell-microbe interactions and demonstrated the adaptability of FMN-green fluorescent protein for studying persistent host infections induced by obligate anaerobic organisms.

  16. Despite differential gene expression profiles pediatric MDS derived mesenchymal stromal cells display functionality in vitro

    Directory of Open Access Journals (Sweden)

    F.G.J. Calkoen

    2015-03-01

    An altered mRNA expression profile, associated with cell survival and malignant transformation, of MSC derived from children with MDS strengthens the hypothesis that the micro-environment is of importance in this disease. Our data support the understanding that pediatric and adult MDS are two different diseases. Further evaluation of the pathways involved might reveal additional therapy targets.

  17. BAG3 promotes the phenotypic transformation of primary rat vascular smooth muscle cells via TRAIL.

    Science.gov (United States)

    Fu, Yao; Chang, Ye; Chen, Shuang; Li, Yuan; Chen, Yintao; Sun, Guozhe; Yu, Shasha; Ye, Ning; Li, Chao; Sun, Yingxian

    2018-05-01

    Under normal physiological condition, the mature vascular smooth muscle cells (VSMCs) show differentiated phenotype. In response to various environmental stimuluses, VSMCs convert from the differentiated phenotype to dedifferentiated phenotype characterized by the increased ability of proliferation/migration and the reduction of contractile ability. The phenotypic transformation of VSMCs played an important role in atherosclerosis. Both Bcl-2-associated athanogene 3 (BAG3) and tumor necrosis factor-related apopt-osis inducing ligand (TRAIL) involved in apoptosis. The relationship between BAG3 and TRAIL and their effects the proliferation and migration in VSMCs are rarely reported. This study investigated the effects of BAG3 on the phenotypic modulation and the potential underlying mechanisms in primary rat VSMCs. Primary rat VSMCs were extracted and cultured in vitro. Cell proliferation was detected by cell counting, real-time cell analyzer (RTCA) and EdU incorporation. Cell migration was detected by wound healing, Transwell and RTCA. BAG3 and TRAIL were detected using real-time PCR and western blotting and the secreted proteins in the cultured media by dot blot. The expression of BAG3 increased with continued passages in cultured primary VSMCs. BAG3 promoted the proliferation and migration of primary rat VSMC in a time-dependent manner. BAG3 significantly increased the expression of TRAIL while had no effects on its receptors. TRAIL knockdown or blocking by neutralizing antibody inhibited the proliferation of VSMCs induced by BAG3. TRAIL knockdown exerted no obvious influence on the migration of VSMCs. Based on this study, we report for the first time that BAG3 was expressed in cultured primary rat VSMCs and the expression of BAG3 increased with continued passages. Furthermore, BAG3 promoted the proliferation of VSMCs via increasing the expression of TRAIL. In addition, we also demonstrated that BAG3 promoted the migration of VSMCs independent of TRAIL

  18. Activation of MEK1 or MEK2 isoform is sufficient to fully transform intestinal epithelial cells and induce the formation of metastatic tumors

    International Nuclear Information System (INIS)

    Voisin, Laure; Basik, Mark; Meloche, Sylvain; Julien, Catherine; Duhamel, Stéphanie; Gopalbhai, Kailesh; Claveau, Isabelle; Saba-El-Leil, Marc K; Rodrigue-Gervais, Ian Gaël; Gaboury, Louis; Lamarre, Daniel

    2008-01-01

    The Ras-dependent ERK1/2 MAP kinase signaling pathway plays a central role in cell proliferation control and is frequently activated in human colorectal cancer. Small-molecule inhibitors of MEK1/MEK2 are therefore viewed as attractive drug candidates for the targeted therapy of this malignancy. However, the exact contribution of MEK1 and MEK2 to the pathogenesis of colorectal cancer remains to be established. Wild type and constitutively active forms of MEK1 and MEK2 were ectopically expressed by retroviral gene transfer in the normal intestinal epithelial cell line IEC-6. We studied the impact of MEK1 and MEK2 activation on cellular morphology, cell proliferation, survival, migration, invasiveness, and tumorigenesis in mice. RNA interference was used to test the requirement for MEK1 and MEK2 function in maintaining the proliferation of human colorectal cancer cells. We found that expression of activated MEK1 or MEK2 is sufficient to morphologically transform intestinal epithelial cells, dysregulate cell proliferation and induce the formation of high-grade adenocarcinomas after orthotopic transplantation in mice. A large proportion of these intestinal tumors metastasize to the liver and lung. Mechanistically, activation of MEK1 or MEK2 up-regulates the expression of matrix metalloproteinases, promotes invasiveness and protects cells from undergoing anoikis. Importantly, we show that silencing of MEK2 expression completely suppresses the proliferation of human colon carcinoma cell lines, whereas inactivation of MEK1 has a much weaker effect. MEK1 and MEK2 isoforms have similar transforming properties and are able to induce the formation of metastatic intestinal tumors in mice. Our results suggest that MEK2 plays a more important role than MEK1 in sustaining the proliferation of human colorectal cancer cells

  19. Human Adipose Mesenchymal Cells Inhibit Melanocyte Differentiation and the Pigmentation of Human Skin via Increased Expression of TGF-β1.

    Science.gov (United States)

    Klar, Agnes S; Biedermann, Thomas; Michalak, Katarzyna; Michalczyk, Teresa; Meuli-Simmen, Claudia; Scherberich, Arnaud; Meuli, Martin; Reichmann, Ernst

    2017-12-01

    There is accumulating evidence that interactions between epidermal melanocytes and stromal cells play an important role in the regulation of skin pigmentation. In this study we established a pigmented dermo-epidermal skin model, melDESS, of human origin to investigate the effects of distinct stromal cells on melanogenesis. melDESS is a complex, clinically relevant skin equivalent composed of an epidermis containing both melanocytes and keratinocytes. Its dermal compartment consists either of adipose tissue-derived stromal cells, dermal fibroblasts (Fbs), or a mixture of both cell types. These skin substitutes were transplanted for 5 weeks on the backs of immuno-incompetent rats and analyzed. Gene expression and Western blot analyses showed a significantly higher expression of transforming growth factor-β1 by adipose tissue-derived stromal cells compared with dermal Fbs. In addition, we showed that melanocytes responded to the increased levels of transforming growth factor-β1 by down-regulating the expression of key melanogenic enzymes such as tyrosinase. This caused decreased melanin synthesis and, consequently, greatly reduced pigmentation of melDESS. The conclusions are of utmost clinical relevance, namely that adipose tissue-derived stromal cells derived from the hypodermis fail to appropriately interact with epidermal melanocytes, thus preventing the sustainable restoration of the patient's native skin color in bioengineered skin grafts. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Effects of oxygen and misonidazole on cell transformation and cell killing in C3H 10T1/2 cells by X rays in vitro

    International Nuclear Information System (INIS)

    Borsa, J.; Sargent, M.D.; Einspenner, M.; Azzam, E.I.; Raaphorst, G.P.

    1984-01-01

    The effects of oxygen (air) and misonidazole on the transformation and killing of 10T1/2 cells by X rays were examined. The oxygen effect for the cell transformation end point was very similar to that for cell killing. Misonidazole enhanced both cell killing and cell transformation to a similar extent. The enhancement of both end points by misonidazole occurred only in the absence of oxygen during irradiation and was of lesser magnitude than that observed for oxygen. These results demonstrate that the radiation chemical processes leading to cell killing and cell transformation, respectively, are affected similarly by these two enhancers of radiation action. 22 references, 3 figures, 2 tables

  1. MSX-1 gene expression and regulation in embryonic palatal tissue.

    Science.gov (United States)

    Nugent, P; Greene, R M

    1998-01-01

    The palatal cleft seen in Msx-1 knock-out mice suggests a role for this gene in normal palate development. The cleft is presumed secondary to tooth and jaw malformations, since in situ hybridization suggests that Msx-1 mRNA is not highly expressed in developing palatal tissue. In this study we demonstrate, by Northern blot analysis, the expression of Msx-1, but not Msx-2, in the developing palate and in primary cultures of murine embryonic palate mesenchymal cells. Furthermore, we propose a role for Msx-1 in retinoic acid-induced cleft palate, since retinoic acid inhibits Msx-1 mRNA expression in palate mesenchymal cells. We also demonstrate that transforming growth factor beta inhibits Msx-1 mRNA expression in palate mesenchymal cells, with retinoic acid and transforming growth factor beta acting synergistically when added simultaneously to these cells. These data suggest a mechanistic interaction between retinoic acid, transforming growth factor beta, and Msx-1 in the etiology of retinoic acid-induced cleft palate.

  2. BMP-7 enhances cell migration and αvβ3 integrin expression via a c-Src-dependent pathway in human chondrosarcoma cells.

    Directory of Open Access Journals (Sweden)

    Jui-Chieh Chen

    Full Text Available Bone morphogenic protein (BMP-7 is a member of the transforming growth factor (TGF-beta superfamily, which is originally identified based on its ability to induce cartilage and bone formation. In recent years, BMP-7 is also defined as a potent promoter of cell motility, invasion, and metastasis. However, there is little knowledge of the role of BMP-7 and its cellular function in chondrosarcoma cells. In the present study, we investigated the biological impact of BMP-7 on cell motility using transwell assay. In addition, the intracellular signaling pathways were also investigated by pharmacological and genetic approaches. Our results demonstrated that treatment with exogenous BMP-7 markedly increased cell migration by activating c-Src/PI3K/Akt/IKK/NF-κB signaling pathway, resulting in the transactivation of αvβ3 integrin expression. Indeed, abrogation of signaling activation, by chemical inhibition or expression of a kinase dead form of the protein attenuated BMP-7-induced expression of integrin αvβ3 and cell migration. These findings may provide a useful tool for diagnostic/prognostic purposes and even therapeutically in late-stage chondrosarcoma as an anti-metastatic agent.

  3. Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xu [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Wang, Dapeng [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Department of Toxicology, School of Public Health, Guizhou Medical University, Guiyang, Guizhou (China); Ma, Yuan; Xu, Xiguo; Zhu, Zhen; Wang, Xiaojuan; Deng, Hanyi; Li, Chunchun; Chen, Min; Tong, Jian [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China); Yamanaka, Kenzo [Laboratory of Environmental Toxicology and Carcinogenesis, School of Pharmacy, Nihon University, Chiba (Japan); An, Yan, E-mail: dranyan@126.com [Department of Toxicology, School of Public Health, Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Diseases, Medical College of Soochow University, Suzhou, Jiangsu (China)

    2015-12-01

    Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation. - Highlights: • Low level, long term arsenite exposure induces malignant transformation in vitro. • Long term arsenite exposure reduces ROS and MDA levels. • Long term arsenite

  4. Continuous activation of Nrf2 and its target antioxidant enzymes leads to arsenite-induced malignant transformation of human bronchial epithelial cells

    International Nuclear Information System (INIS)

    Yang, Xu; Wang, Dapeng; Ma, Yuan; Xu, Xiguo; Zhu, Zhen; Wang, Xiaojuan; Deng, Hanyi; Li, Chunchun; Chen, Min; Tong, Jian; Yamanaka, Kenzo; An, Yan

    2015-01-01

    Long-term exposure to arsenite leads to human lung cancer, but the underlying mechanisms of carcinogenesis remain obscure. The transcription factor of nuclear factor-erythroid-2 p45-related factor (Nrf2)-mediated antioxidant response represents a critical cellular defense mechanism and protection against various diseases. Paradoxically, emerging data suggest that the constitutive activation of Nrf2 is associated with cancer development, progression and chemotherapy resistance. However, the role of Nrf2 in the occurrence of cancer induced by long-term arsenite exposure remains to be fully understood. By establishing transformed human bronchial epithelial (HBE) cells via chronic low-dose arsenite treatment, we showed that, in acquiring this malignant phenotype, continuous low level of ROS and sustained enhancement of Nrf2 and its target antioxidant enzyme levels were observed in the later-stage of arsenite-induced cell transformation. The downregulation of Keap1 level may be responsible for the over-activation of Nrf2 and its target enzymes. To validate these observations, Nrf2 was knocked down in arsenite-transformed HBE cells by SiRNA transfection, and the levels of Nrf2 and its target antioxidant enzymes, ROS, cell proliferation, migration, and colony formation were determined following these treatments. Results showed that blocked Nrf2 expression significantly reduced Nrf2 and its target antioxidant enzyme levels, restored ROS levels, and eventually suppressed cell proliferation, migration, and colony formation of the transformed cells. In summary, the results of the study strongly suggested that the continuous activation of Nrf2 and its target antioxidant enzymes led to the over-depletion of intracellular ROS levels, which contributed to arsenite-induced HBE cell transformation. - Highlights: • Low level, long term arsenite exposure induces malignant transformation in vitro. • Long term arsenite exposure reduces ROS and MDA levels. • Long term arsenite

  5. Deregulation of histone lysine methyltransferases contributes to oncogenic transformation of human bronchoepithelial cells

    Directory of Open Access Journals (Sweden)

    Yoda Satoshi

    2008-11-01

    Full Text Available Abstract Background Alterations in the processing of the genetic information in carcinogenesis result from stable genetic mutations or epigenetic modifications. It is becoming clear that nucleosomal histones are central to proper gene expression and that aberrant DNA methylation of genes and histone methylation plays important roles in tumor progression. To date, several histone lysine methyltransferases (HKMTs have been identified and histone lysine methylation is now considered to be a critical regulator of transcription. However, still relatively little is known about the role of HKMTs in tumorigenesis. Results We observed differential HKMT expression in a lung cancer model in which normal human bronchial epithelial (NHBE cells expressing telomerase, SV40 large T antigen, and Ras were immortal, formed colonies in soft agar, and expressed specific HKMTs for H3 lysine 9 and 27 residues but not for H3 lysine 4 residue. Modifications in the H3 tails affect the binding of proteins to the histone tails and regulate protein function and the position of lysine methylation marks a gene to be either activated or repressed. In the present study, suppression by siRNA of HKMTs (EZH2, G9A, SETDB1 and SUV39H1 that are over-expressed in immortalized and transformed cells lead to reduced cell proliferation and much less anchorage-independent colony growth. We also found that the suppression of H3-K9, G9A and SUV39H1 induced apoptosis and the suppression of H3-K27, EZH2 caused G1 arrest. Conclusion Our results indicate the potential of these HKMTs in addition to the other targets for epigenetics such as DNMTs and HDACs to be interesting therapeutic targets.

  6. Profiles of Gene Expression Induced by Ionizing Radiation in Different Human Cell Types. Doctoral thesis prepared at SCK-CEN and defended in 2005

    International Nuclear Information System (INIS)

    Mori, M.

    2006-01-01

    Ionizing radiation disrupts chemical bonds in biomolecules, such as proteins and DNA, which result in important cellular damage. Exposure to relatively high doses of ionizing radiation such as those delivered to the tumor in a radiotherapy protocol is generally lethal for the cell. However, non-lethal dose of ionizing radiation can be delivered during radiotherapy to the healthy tissue surrounding the tumor. Although the effects of ionizing radiation at the cellular level are quite well established (cell cycle arrest, senescence, apoptosis, mitotic catastrophe), questions remain concerning the molecular pathways regulating these cellular responses, including those differentiating the responses between tumor and normal cells. In normal cells, the p53 protein plays a central role. However, the efficacy of radiation treatments on tumor cells is often reduced because of the frequent inactivation of the p53 protein in those cells. Our study used the microarray technology to investigate the molecular pathways induced by irradiation in transformed and nontransformed human cells. Profiles of gene expression obtained with cDNA microarrays were regarded as steps to characterize the general response to ionizing radiation and, possibly also, differentiating the response between transformed and nontransformed cells. Possible implications of such research include the development of radiosensitizing (to maximize the effect of radiotherapeutic irradiation) and of radioprotecting strategies. Transcriptional profiles were investigated in transformed (Jurkat, HL60) and non-transformed (freshly isolated lymphocyte subpopulations) cells of hematopoietic origin. Also, because HeLa carcinoma-derived cells expressing human papilloma virus (HPV) 18 derived E2 protein represent a reliable model to study the p53 pathway, which is normally activated in response to radiation, molecular profiles were obtained to characterize this pathway in these cells

  7. GBM secretome induces transient transformation of human neural precursor cells.

    Science.gov (United States)

    Venugopal, Chitra; Wang, X Simon; Manoranjan, Branavan; McFarlane, Nicole; Nolte, Sara; Li, Meredith; Murty, Naresh; Siu, K W Michael; Singh, Sheila K

    2012-09-01

    Glioblastoma (GBM) is the most aggressive primary brain tumor in humans, with a uniformly poor prognosis. The tumor microenvironment is composed of both supportive cellular substrates and exogenous factors. We hypothesize that exogenous factors secreted by brain tumor initiating cells (BTICs) could predispose normal neural precursor cells (NPCs) to transformation. When NPCs are grown in GBM-conditioned media, and designated as "tumor-conditioned NPCs" (tcNPCs), they become highly proliferative and exhibit increased stem cell self-renewal, or the unique ability of stem cells to asymmetrically generate another stem cell and a daughter cell. tcNPCs also show an increased transcript level of stem cell markers such as CD133 and ALDH and growth factor receptors such as VEGFR1, VEGFR2, EGFR and PDGFRα. Media analysis by ELISA of GBM-conditioned media reveals an elevated secretion of growth factors such as EGF, VEGF and PDGF-AA when compared to normal neural stem cell-conditioned media. We also demonstrate that tcNPCs require prolonged or continuous exposure to the GBM secretome in vitro to retain GBM BTIC characteristics. Our in vivo studies reveal that tcNPCs are unable to form tumors, confirming that irreversible transformation events may require sustained or prolonged presence of the GBM secretome. Analysis of GBM-conditioned media by mass spectrometry reveals the presence of secreted proteins Chitinase-3-like 1 (CHI3L1) and H2A histone family member H2AX. Collectively, our data suggest that GBM-secreted factors are capable of transiently altering normal NPCs, although for retention of the transformed phenotype, sustained or prolonged secretome exposure or additional transformation events are likely necessary.

  8. Expression of C4.4A in precursor lesions of pulmonary adenocarcinoma and squamous cell carcinoma

    DEFF Research Database (Denmark)

    Jacobsen, Benedikte; Santoni-Rugiu, Eric; Illemann, Martin

    2012-01-01

    in precursor lesions of lung squamous cell carcinoma and adenocarcinoma was investigated by stainings with a specific anti-C4.4A antibody. In the transformation from normal bronchial epithelium to squamous cell carcinoma, C4.4A was weakly expressed in basal cell hyperplasia but dramatically increased...... in squamous metaplasia. This was confined to the cell membrane and sustained in dysplasia, carcinoma in situ, and the invasive carcinoma. The induction of C4.4A already at the stage of hyperplasia could indicate that it is a marker of very early squamous differentiation, which aligns well with our earlier...... finding that C4.4A expression levels do not provide prognostic information on the survival of squamous cell carcinoma patients. In the progression from normal alveolar epithelium to peripheral adenocarcinoma, we observed an unexpected, distinct cytoplasmic staining for C4.4A in a fraction of atypical...

  9. Vanillin production using Escherichia coli cells over-expressing isoeugenol monooxygenase of Pseudomonas putida.

    Science.gov (United States)

    Yamada, Mamoru; Okada, Yukiyoshi; Yoshida, Toyokazu; Nagasawa, Toru

    2008-04-01

    The isoeugenol monooxygenase gene of Pseudomonas putida IE27 was inserted into an expression vector, pET21a, under the control of the T7 promoter. The recombinant plasmid was introduced into Escherichia coli BL21(DE3) cells, containing no vanillin-degrading activity. The transformed E. coli BL21(DE3) cells produced 28.3 g vanillin/l from 230 mM isoeugenol, with a molar conversion yield of 81% at 20 degrees C after 6 h. In the reaction system, no accumulation of undesired by-products, such as vanillic acid or acetaldehyde, was observed.

  10. Room temperature electrocompetent bacterial cells improve DNA transformation and recombineering efficiency.

    Science.gov (United States)

    Tu, Qiang; Yin, Jia; Fu, Jun; Herrmann, Jennifer; Li, Yuezhong; Yin, Yulong; Stewart, A Francis; Müller, Rolf; Zhang, Youming

    2016-04-20

    Bacterial competent cells are essential for cloning, construction of DNA libraries, and mutagenesis in every molecular biology laboratory. Among various transformation methods, electroporation is found to own the best transformation efficiency. Previous electroporation methods are based on washing and electroporating the bacterial cells in ice-cold condition that make them fragile and prone to death. Here we present simple temperature shift based methods that improve DNA transformation and recombineering efficiency in E. coli and several other gram-negative bacteria thereby economizing time and cost. Increased transformation efficiency of large DNA molecules is a significant advantage that might facilitate the cloning of large fragments from genomic DNA preparations and metagenomics samples.

  11. Role of DNA lesions and repair in the transformation of human cells

    International Nuclear Information System (INIS)

    Maher, V.M.; McCormick, J.J.

    1987-01-01

    Results of studies on the transformation of diploid human fibroblasts in culture into tumor-forming cells by exposure to chemical carcinogens or radiation indicate that such transformation is multi-stepped process that at least one step, acquisition of anchorage independence, occurs as a mutagenic event. Studies comparing normal-repairing human cells with DNA repair-deficient cells, such as those derived from cancer-prone xeroderma pigmentosum patients, indicate that excision repair in human fibroblasts is essentially an error-free process that the ability to excise potentially cytotoxic, mutagenic, or transforming lesions induced DNA by carcinogens determines their ultimate biological consequences. Cells deficient in excision repair are abnormally sensitive to these agents. Studies with cells treated at various times in the cell cycle show that there is a certain limited amount of time available for DNA repair between the initial exposure and the onset of the cellular event responsible for mutation induction and transformation to anchorage independence. The data suggest that DNA replication on a template containing unexcised lesions (photoproducts, adducts) is the critical event

  12. cDNA sequence of human transforming gene hst and identification of the coding sequence required for transforming activity

    International Nuclear Information System (INIS)

    Taira, M.; Yoshida, T.; Miyagawa, K.; Sakamoto, H.; Terada, M.; Sugimura, T.

    1987-01-01

    The hst gene was originally identified as a transforming gene in DNAs from human stomach cancers and from a noncancerous portion of stomach mucosa by DNA-mediated transfection assay using NIH3T3 cells. cDNA clones of hst were isolated from the cDNA library constructed from poly(A) + RNA of a secondary transformant induced by the DNA from a stomach cancer. The sequence analysis of the hst cDNA revealed the presence of two open reading frames. When this cDNA was inserted into an expression vector containing the simian virus 40 promoter, it efficiently induced the transformation of NIH3T3 cells upon transfection. It was found that one of the reading frames, which coded for 206 amino acids, was responsible for the transforming activity

  13. Transformation and scattering activities of the receptor tyrosine kinase RON/Stk in rodent fibroblasts and lack of regulation by the jaagsiekte sheep retrovirus receptor, Hyal2

    International Nuclear Information System (INIS)

    Miller, A Dusty; Van Hoeven, Neal S; Liu, Shan-Lu

    2004-01-01

    The envelope (Env) protein of jaagsiekte sheep retrovirus (JSRV) can transform cells in culture and is likely to be the main factor responsible for lung cancer induction by JSRV in animals. A recent report indicates that the epithelial-cell transforming activity of JSRV Env depends on activation of the cell-surface receptor tyrosine kinase Mst1r (called RON for the human and Stk for the rodent orthologs). In the immortalized line of human epithelial cells used (BEAS-2B cells), the virus receptor Hyal2 was found to bind to and suppress the activity of RON. When Env was expressed it bound to Hyal2 causing its degradation, release of RON activity from Hyal2 suppression, and activation of pathways resulting in cell transformation. Due to difficulty with reproducibility of the transformation assay in BEAS-2B cells, we have used more tractable rodent fibroblast models to further study Hyal2 modulation of RON/Stk transforming activity and potential effects of Hyal2 on RON/Stk activation by its natural ligand, macrophage stimulating protein (MSP). We did not detect transformation of NIH 3T3 cells by plasmids expressing RON or Stk, but did detect transformation of 208F rat fibroblasts by these plasmids at a very low rate. We were able to isolate 208F cell clones that expressed RON or Stk and that showed changes in morphology indicative of transformation. The parental 208F cells did not respond to MSP but 208F cells expressing RON or Stk showed obvious increases in scattering/transformation in response to MSP. Human Hyal2 had no effect on the basal or MSP-induced phenotypes of RON-expressing 208F cells, and human, mouse or rat Hyal2 had no effect on the basal or MSP-induced phenotypes of Stk-expressing 208F cells. We have shown that RON or Stk expression in 208F rat fibroblasts results in a transformed phenotype that is enhanced by addition of the natural ligand for these proteins, MSP. Hyal2 does not directly modulate the basal or MSP-induced RON/Stk activity, although it

  14. Fractalkine expression induces endothelial progenitor cell lysis by natural killer cells.

    Directory of Open Access Journals (Sweden)

    Dilyana Todorova

    Full Text Available BACKGROUND: Circulating CD34(+ cells, a population that includes endothelial progenitors, participate in the maintenance of endothelial integrity. Better understanding of the mechanisms that regulate their survival is crucial to improve their regenerative activity in cardiovascular and renal diseases. Chemokine-receptor cross talk is critical in regulating cell homeostasis. We hypothesized that cell surface expression of the chemokine fractalkine (FKN could target progenitor cell injury by Natural Killer (NK cells, thereby limiting their availability for vascular repair. METHODOLOGY/PRINCIPAL FINDINGS: We show that CD34(+-derived Endothelial Colony Forming Cells (ECFC can express FKN in response to TNF-α and IFN-γ inflammatory cytokines and that FKN expression by ECFC stimulates NK cell adhesion, NK cell-mediated ECFC lysis and microparticles release in vitro. The specific involvement of membrane FKN in these processes was demonstrated using FKN-transfected ECFC and anti-FKN blocking antibody. FKN expression was also evidenced on circulating CD34(+ progenitor cells and was detected at higher frequency in kidney transplant recipients, when compared to healthy controls. The proportion of CD34(+ cells expressing FKN was identified as an independent variable inversely correlated to CD34(+ progenitor cell count. We further showed that treatment of CD34(+ circulating cells isolated from adult blood donors with transplant serum or TNF-α/IFN-γ can induce FKN expression. CONCLUSIONS: Our data highlights a novel mechanism by which FKN expression on CD34(+ progenitor cells may target their NK cell mediated killing and participate to their immune depletion in transplant recipients. Considering the numerous diseased contexts shown to promote FKN expression, our data identify FKN as a hallmark of altered progenitor cell homeostasis with potential implications in better evaluation of vascular repair in patients.

  15. X-ray-induced in vitro neoplastic transformation of human diploid cells

    International Nuclear Information System (INIS)

    Borek, C.

    1980-01-01

    Techniques have recently been developed to identify and score quantitatively neoplastic transformation caused by x-rays in cultured cells derived from rodents. The present report describes for the first time the neoplastic transformation in vitro of human diploid cells by x-ray irradiation into cells which can progress in vitro into advanced stages of neoplastic development, namely, to form colonies in agar and give rise to tumors when injected into nude mice

  16. Identification of differentially expressed proteins between human esophageal immortalized and carcinomatous cell lines by two-dimensional electrophoresis and MALDI-TOF-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    Xing-Dong Xiong; Li-Yan Xu; Zhong-Ying Shen; Wei-Jia Cai; Jian-Min Luo; Ya-Li Han; En-Min Li

    2002-01-01

    AIM: To identify the differentially expressed proteins between the human immortalized esophageal epithelial cell line (SHEE) and the malignant transformed esophageal carcinoma cell line (SHEEC), and to explore new ways for studying esophageal carcinoma associated genes. METHODS: SHEE and SHEEC cell lines were used to separate differentially expressed proteins by two-dimensional electrophoresis/The silver-stained 2-D gels was scanned with EDAS290 digital camera system and analyzed with the PDQuest 6.2 Software. Six spots in which the differentially expressed protein was more obvious were selected and analyzed with matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS).RESULTS: There were 107±4.58 and 115±9.91 protein spots observed in SHEE and SHEEC respectively, and the majority of these spots between the two cell lines matched each other (r=-0.772), only a few were expressed differentially. After analyzed by MALDI-TOF-MS and database search for the six differentially expressed proteins, One new protein as well as other five sequence-known proteins including RNPEP-like protein, human rRNA gene upstream sequence binding transcription factor, uracil DNA glycosylase,Annexin A2 and p300/CBP-associated factor were preliminarily identified.CONCLUSION: These differentially expressed proteins might play an importance role during malignant transformation of SHEEC from SHEE. The identification of these proteins may serve as a new way for studying esophageal carcinoma associated genes.

  17. Alteration in gene expression profile and oncogenicity of esophageal squamous cell carcinoma by RIZ1 upregulation.

    Science.gov (United States)

    Dong, Shang-Wen; Li, Dong; Xu, Cong; Sun, Pei; Wang, Yuan-Guo; Zhang, Peng

    2013-10-07

    To investigate the effect of retinoblastoma protein-interacting zinc finger gene 1 (RIZ1) upregulation in gene expression profile and oncogenicity of human esophageal squamous cell carcinoma (ESCC) cell line TE13. TE13 cells were transfected with pcDNA3.1(+)/RIZ1 and pcDNA3.1(+). Changes in gene expression profile were screened and the microarray results were confirmed by reverse transcription-polymerase chain reaction (RT-PCR). Nude mice were inoculated with TE13 cells to establish ESCC xenografts. After two weeks, the inoculated mice were randomly divided into three groups. Tumors were injected with normal saline, transfection reagent pcDNA3.1(+) and transfection reagent pcDNA3.1(+)/RIZ1, respectively. Tumor development was quantified, and changes in gene expression of RIZ1 transfected tumors were detected by RT-PCR and Western blotting. DNA microarray data showed that RIZ1 transfection induced widespread changes in gene expression profile of cell line TE13, with 960 genes upregulated and 1163 downregulated. Treatment of tumor xenografts with RIZ1 recombinant plasmid significantly inhibited tumor growth, decreased tumor size, and increased expression of RIZ1 mRNA compared to control groups. The changes in gene expression profile were also observed in vivo after RIZ1 transfection. Most of the differentially expressed genes were associated with cell development, supervision of viral replication, lymphocyte costimulatory and immune system development in esophageal cells. RIZ1 gene may be involved in multiple cancer pathways, such as cytokine receptor interaction and transforming growth factor beta signaling. The development and progression of esophageal cancer are related to the inactivation of RIZ1. Virus infection may also be an important factor.

  18. Mitochondrial ribosomal protein S18-2 evokes chromosomal instability and transforms primary rat skin fibroblasts

    KAUST Repository

    Kashuba, Elena

    2015-05-12

    We have shown earlier that overexpression of the human mitochondrial ribosomal protein MRPS18-2 (S18-2) led to immortalization of primary rat embryonic fibroblasts. The derived cells expressed the embryonic stem cell markers, and cellular pathways that control cell proliferation, oxidative phosphorylation, cellular respiration, and other redox reactions were activated in the immortalized cells. Here we report that, upon overexpression of S18-2 protein, primary rat skin fibroblasts underwent cell transformation. Cells passed more than 300 population doublings, and two out of three tested clones gave rise to tumors in experimental animals. Transformed cells showed anchorage-independent growth and loss of contact inhibition; they expressed epithelial markers, such as E-cadherin and β-catenin. Transformed cells showed increased telomerase activity, disturbance of the cell cycle, and chromosomal instability. Taken together, our data suggest that S18-2 is a newly identified oncoprotein that may be involved in cancerogenesis.

  19. Battery Cell Voltage Sensing and Balancing Using Addressable Transformers

    Science.gov (United States)

    Davies, Francis

    2009-01-01

    A document discusses the use of saturating transformers in a matrix arrangement to address individual cells in a high voltage battery. This arrangement is able to monitor and charge individual cells while limiting the complexity of circuitry in the battery. The arrangement has inherent galvanic isolation, low cell leakage currents, and allows a single bad cell in a battery of several hundred cells to be easily spotted.

  20. High value of the radiobiological parameter Dq correlates to expression of the transforming growth factor beta type II receptor in a panel of small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Krarup, M; Nørgaard, P

    1998-01-01

    Our panel of SCLC cell lines have previously been examined for their radiobiological characteristics and sensitivity to treatment with TGF beta 1. In this study we examined the possible correlations between radiobiological parameters and the expression of the TGF beta type II receptor (TGF beta......-rII). We have, in other studies, shown that the presence of TGF beta-rII was mandatory for transmitting the growth inhibitory effect of TGF beta. The results showed a statistically significant difference in Dq, i.e. the shoulder width of the survival curve, between cell lines expressing TGF beta......-rII and cell lines which did not express the receptor (P = 0.01). Cell lines expressing TGF beta-rII had a high Dq-value. TGF beta-rII expression did not correlate with any other radiobiological parameters. We suggest that an intact growth inhibitory pathway mediated by the TGF beta-rII may have a significant...

  1. Characterization of a human cell line stably over-expressing the candidate oncogene, dual specificity phosphatase 12.

    Directory of Open Access Journals (Sweden)

    Erica L Cain

    2011-04-01

    Full Text Available Analysis of chromosomal rearrangements within primary tumors has been influential in the identification of novel oncogenes. Identification of the "driver" gene(s within cancer-derived amplicons is, however, hampered by the fact that most amplicons contain many gene products. Amplification of 1q21-1q23 is strongly associated with liposarcomas and microarray-based comparative genomic hybridization narrowed down the likely candidate oncogenes to two: the activating transcription factor 6 (atf6 and the dual specificity phosphatase 12 (dusp12. While atf6 is an established transcriptional regulator of the unfolded protein response, the potential role of dusp12 in cancer remains uncharacterized.To evaluate the oncogenic potential of dusp12, we established stable cell lines that ectopically over-express dusp12 in isolation and determined whether this cell line acquired properties frequently associated with transformed cells. Here, we demonstrate that cells over-expressing dusp12 display increased cell motility and resistance to apoptosis. Additionally, over-expression of dusp12 promoted increased expression of the c-met proto-oncogene and the collagen and laminin receptor intergrin alpha 1 (itga1 which is implicated in metastasis.Collectively, these results suggest that dusp12 is oncologically relevant and exposes a potential association between dusp12 and established oncogenes that could be therapeutically targeted.

  2. Combined introduction of Bmi-1 and hTERT immortalizes human adipose tissue-derived stromal cells with low risk of transformation

    International Nuclear Information System (INIS)

    Tátrai, Péter; Szepesi, Áron; Matula, Zsolt; Szigeti, Anna; Buchan, Gyöngyi; Mádi, András; Uher, Ferenc

    2012-01-01

    Highlights: ► We immortalized human adipose stromal cells (ASCs) with hTERT, Bmi-1, and SV40T. ► hTERT-only ASCs are prone to transformation, while Bmi-only ASCs become senescent. ► SV40T introduced along with hTERT abrogates proliferation control and multipotency. ► hTERT combined with Bmi-1 yields stable phenotype up to 140 population doublings. -- Abstract: Adipose tissue-derived stromal cells (ASCs) are increasingly being studied for their usefulness in regenerative medicine. However, limited life span and donor-dependent variation of primary cells such as ASCs present major hurdles to controlled and reproducible experiments. We therefore aimed to establish immortalized ASC cell lines that provide steady supply of homogeneous cells for in vitro work while retain essential features of primary cells. To this end, combinations of human telomerase reverse transcriptase (hTERT), murine Bmi-1, and SV40 large T antigen (SV40T) were introduced by lentiviral transduction into ASCs. The resulting cell lines ASC hTERT , ASC Bmi-1 , ASC Bmi-1+hTERT and ASC SV40T+hTERT were tested for transgene expression, telomerase activity, surface immunomarkers, proliferation, osteogenic and adipogenic differentiation, karyotype, tumorigenicity, and cellular senescence. All cell lines have maintained expression of characteristic surface immunomarkers, and none was tumorigenic. However, ASC Bmi-1 had limited replicative potential, while the rapidly proliferating ASC SV40T+hTERT acquired chromosomal aberrations, departed from MSC phenotype, and lost differentiation capacity. ASC hTERT and ASC hTERT+Bmi-1 , on the other hand, preserved all essential MSC features and did not senesce after 100 population doublings. Notably, a subpopulation of ASC hTERT also acquired aberrant karyotype and showed signs of transformation after long-term culture. In conclusion, hTERT alone was sufficient to extend the life span of human ASC, but ASC hTERT are prone to transformation during extensive

  3. Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

    Science.gov (United States)

    Huckleberry, Kylie A.; Kane, Gary A.; Mathis, Rita J.; Cook, Sarah G.; Clutton, Jonathan E.; Drew, Michael R.

    2015-01-01

    Thousands of neurons are born each day in the dentate gyrus (DG), but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in the DG. The immediate-early gene (IEG) zif268 appears to be an important mediator of these effects, as its expression can be induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Richardson et al., 1992; Veyrac et al., 2013). Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs). We first quantified zif268 expression in doublecortin-positive (DCX+) immature neurons and in the general granule cell population after brief exposure to a novel environment (NE). In the general granule cell population, zif268 expression peaked 1 h after NE exposure and returned to baseline by 8 h post-exposure. However, in the DCX+ cells, zif268 expression was suppressed relative to home cage for at least 8 h post-exposure. We next asked whether suppression of zif268 in DCX+ immature cells occurs in other behavioral paradigms that recruit the hippocampus. Exposure to Morris water maze (MWM) training, an enriched environment, or a NE caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 expression among the general granule cell population. The same behavioral procedures activated zif268 expression in 6-week-old BrdU-labeled adult-born neurons, indicating that zif268 suppression is specific to immature neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. NE exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly

  4. HIF2A and IGF2 Expression Correlates in Human Neuroblastoma Cells and Normal Immature Sympathetic Neuroblasts

    Directory of Open Access Journals (Sweden)

    Sofie Mohlin

    2013-03-01

    Full Text Available During normal sympathetic nervous system (SNS development, cells of the ganglionic lineage can malignantly transform and develop into the childhood tumor neuroblastoma. Hypoxia-inducible transcription factors (HIFs mediate cellular responses during normal development and are central in the adaptation to oxygen shortage. HIFs are also implicated in the progression of several cancer forms, and high HIF-2α expression correlates with disseminated disease and poor outcome in neuroblastoma. During normal SNS development, HIF2A is transiently expressed in neuroblasts and chromaffin cells. SNS cells can, during development, be distinguished by distinct gene expression patterns, and insulin-like growth factor 2 (IGF2 is a marker of sympathetic chromaffin cells, whereas sympathetic neuroblasts lack IGF2 expression. Despite the neuronal derivation of neuroblastomas, we show that neuroblastoma cell lines and specimens express IGF2 and that expression of HIF2A and IGF2 correlates, with the strongest correlation in high-stage tumors. In neuroblastoma, both IGF2 and HIF2A are hypoxia-driven and knocking down IGF2 at hypoxia resulted in downregulated HIF2A levels. HIF-2α and IGF2 were strongly expressed in subsets of immature neuroblastoma cells, suggesting that these two genes could be co-expressed also at early stages of SNS development. We show that IGF2 is indeed expressed in sympathetic chain ganglia at embryonic week 6.5, a developmental stage when HIF-2α is present. These findings provide a rationale for the unexpected IGF2 expression in neuroblastomas and might suggest that IGF2 and HIF2A positive neuroblastoma cells are arrested at an embryonic differentiation stage corresponding to the stage when sympathetic chain ganglia begins to coalesce.

  5. Immunogenicity of guinea pig cells transformed in culture by chemical carcinogens.

    Science.gov (United States)

    Ohanian, S H; McCabe, R P; Evans, C H

    1981-12-01

    The immunogenicity of inbred strain 2/N guinea pig fibroblasts transformed to the malignant state in vitro by chemical carcinogens was evaluated with the use of a variety of in vivo and in vitro methods including delayed-type hypersensitivity skin and tumor transplantation tests and analysis of antibody production by immunofluorescence, complement fixation, and staphylococcal protein A binding tests. Neoplastic transformation was induced by direct treatment of cells in culture with benzo[a]pyrene, 3-methylcholanthrene, or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or by the host-mediated method by which fetuses were exposed to diethylnitrosamine or MNNG in vivo prior to cell culture. Rabbits and syngeneic guinea pigs were inoculated with unirradiated and X-irradiated clonally derived cells. Delayed hypersensitivity skin reactions to immunizing or other cells were equivalent in immunized or control guinea pigs, and no protection to tumor outgrowth from a challenge inoculum of immunizing cells was observed. Antibody activity induced in the sera of immunized guinea pigs was cross-reactive and removed by absorption with nontumorigenic cells. Rabbit antisera after absorption with fetal guinea pig cells were nonreactive with the specific immunizing or other culture cells. Chemical carcinogen-induced neoplastic transformation of guinea pig cells can, therefore, occur without formation of detectable, individually distinct cell surface tumor-specific neoantigens.

  6. Immunogenicity of guinea pig cells transformed in culture by chemical carcinogens

    International Nuclear Information System (INIS)

    Ohanian, S.H.; McCabe, R.P.; Evans, C.H.

    1981-01-01

    The immunogenicity of inbred strain 2/N guinea pig fibroblasts transformed to the malignant state in vitro by chemical carcinogens was evaluated with the use of a variety of in vivo and in vitro methods including delayed-type hypersensitivity skin and tumor transplantation tests and analysis of antibody production by immunofluorescence, complement fixation, and staphylococcal protein A binding tests. Neoplastic transformation was induced by direct treatment of cells in culture with benzo[a]pyrene, 3-methylcholanthrene, or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or by the host-mediated method by which fetuses were exposed to diethylnitrosamine or MNNG in vivo prior to cell culture. Rabbits and syngeneic guinea pigs were inoculated with unirradiated and X-irradiated clonally derived cells. Delayed hypersensitivity skin reactions to immunizing or other cells were equivalent in immunized or control guinea pigs, and no protection to tumor outgrowth from a challenge inoculum of immunizing cells was observed. Antibody activity induced in the sera of immunized guinea pigs was cross-reactive and removed by absorption with nontumorigenic cells. Rabbit anitsera after absorption with fetal guinea pig cells were nonreactive with the specific immunizing or other cultured cells. Chemical carcinogen-induced neoplastic transformation of guinea pig cells can, therefore, occur without formation of detectable, individually distinct cell surface tumor-specific neoantigens

  7. Ultraviolet-x-ray interaction: mutation and transformation

    International Nuclear Information System (INIS)

    Han, A.; Elkind, M.M.; Suzuki, F.; Dainko, J.L.; Buess, E.

    1981-01-01

    The overall long-range objectives of the proposed research are to: (1) determine whether ionizing and nonionizing radiations interact in the induction of mutation and neoplastic transformation; (2) identify the nature of the interaction; (3) establish the possible relationship between the repair processes and the expression of interactive damage related to mutation and neoplastic transformation. Principal methods were used to assess survival, mutation, and neoplastic transformation of mammalian cells in culture. Cells were exposed to the following radiations: 50-kV x-rays; light from a germicidal lamp, uv-C (254 nm); light from unfiltered sun lamps, uv-B (290 to 345 nm); and light from sun lamps filtered by polystyrene dish covers

  8. Malignant human cell transformation of Marcellus Shale gas drilling flow back water

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yixin [Department of Epidemiology, Shanghai Jiaotong University School of Public Health (China); Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States); Chen, Tingting [School of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Shen, Steven S. [Biochemistry and Molecular Pharmaceutical, New York University School of Medicine (United States); Niu, Yingmei; DesMarais, Thomas L.; Linn, Reka; Saunders, Eric; Fan, Zhihua [Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States); Lioy, Paul [Robert Wood Johnson Medical School Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Kluz, Thomas; Chen, Lung-Chi [Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States); Wu, Zhuangchun, E-mail: wuzhuangchun@mail.njust.edu.cn [College of Science, Donghua University, Shanghai 201620 (China); Costa, Max, E-mail: max.costa@nyumc.org [Department of Environmental Medicine, New York University School of Medicine, Tuxedo, NY 10987 (United States)

    2015-10-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation are known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these wastewaters, flow back waters from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy/energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC{sub 50} values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found to be elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6 weeks with flow back waters produced colony formation in soft agar that was concentration dependent. In addition, flow back water-transformed BEAS-2B cells show better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. - Highlights: • This is the first report of potential cytotoxicity and transforming activity of Marcellus shale gas mining flow back to mammalian cells. • Barium and Strontium were elevated in flow back water exposed cells. • Flow back water malignantly transformed cells and formed tumor in athymic nude mice. • Flow back transformed cells exhibited altered transcriptome with dysregulated cell migration pathway and adherent junction pathway.

  9. Malignant human cell transformation of Marcellus Shale gas drilling flow back water

    International Nuclear Information System (INIS)

    Yao, Yixin; Chen, Tingting; Shen, Steven S.; Niu, Yingmei; DesMarais, Thomas L.; Linn, Reka; Saunders, Eric; Fan, Zhihua; Lioy, Paul; Kluz, Thomas; Chen, Lung-Chi; Wu, Zhuangchun; Costa, Max

    2015-01-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation are known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these wastewaters, flow back waters from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy/energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC 50 values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found to be elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6 weeks with flow back waters produced colony formation in soft agar that was concentration dependent. In addition, flow back water-transformed BEAS-2B cells show better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. - Highlights: • This is the first report of potential cytotoxicity and transforming activity of Marcellus shale gas mining flow back to mammalian cells. • Barium and Strontium were elevated in flow back water exposed cells. • Flow back water malignantly transformed cells and formed tumor in athymic nude mice. • Flow back transformed cells exhibited altered transcriptome with dysregulated cell migration pathway and adherent junction pathway.

  10. Malignant transformation of diploid human fibroblasts by transfection of oncogenes. Part 2, Progress report, July 1989--June 1992

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, J.J.

    1992-12-31

    This document consist of brief reports prepared by postdoctoral students supported by the project, each describing his accomplishments under the grant. Topics include (1) Malignant Transformation of MSU-1. 1 Cells by Gamma Radiation, (2) Correlation between Levels of ras Expression and Presence of Transformed Phenotypes Including Tumorigenicity, Using a Modulatable Promoter, (3) Relation between Specific rad Oncogene Expression, (4) Correlation of Genetic Changes in Fibroblastic Tumors with Malignancies, (5)Transformation of MSU-1.1 Cells by sis Oncogene, (6) Malignant Transformation of MSU-1.0 Cells, (7) Correlation of Urokinase Plasminogen Activation (mu-PA) with Malignant Phenotype, (8)Two Dimensional Gel Electrophoresis Studies of the Proteins of the Major Cell Strains of the MSU-1 Family of Cells, and (9) Correlation between Proteinase Activity Levels and Malignancy.

  11. Proteome-wide analysis of protein abundance and turnover remodelling during oncogenic transformation of human breast epithelial cells [version 1; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Tony Ly

    2018-05-01

    Full Text Available Background: Viral oncogenes and mutated proto-oncogenes are potent drivers of cancer malignancy. Downstream of the oncogenic trigger are alterations in protein properties that give rise to cellular transformation and the acquisition of malignant cellular phenotypes. Developments in mass spectrometry enable large-scale, multidimensional characterisation of proteomes. Such techniques could provide an unprecedented, unbiased view of how oncogene activation remodels a human cell proteome. Methods: Using quantitative MS-based proteomics and cellular assays, we analysed how transformation induced by activating v-Src kinase remodels the proteome and cellular phenotypes of breast epithelial (MCF10A cells. SILAC MS was used to comprehensively characterise the MCF10A proteome and to measure v-Src-induced changes in protein abundance across seven time-points (1-72 hrs. We used pulse-SILAC MS (Boisvert et al., 2012, to compare protein synthesis and turnover in control and transformed cells. Follow-on experiments employed a combination of cellular and functional assays to characterise the roles of selected Src-responsive proteins. Results: Src-induced transformation changed the expression and/or turnover levels of ~3% of proteins, affecting ~1.5% of the total protein molecules in the cell. Transformation increased the average rate of proteome turnover and disrupted protein homeostasis. We identify distinct classes of protein kinetics in response to Src activation. We demonstrate that members of the polycomb repressive complex 1 (PRC1 are important regulators of invasion and migration in MCF10A cells. Many Src-regulated proteins are present in low abundance and some are regulated post-transcriptionally. The signature of Src-responsive proteins is highly predictive of poor patient survival across multiple cancer types. Open access to search and interactively explore all these proteomic data is provided via the EPD database (www.peptracker.com/epd. Conclusions

  12. Static harmonization of dynamically harmonized Fourier transform ion cyclotron resonance cell.

    Science.gov (United States)

    Zhdanova, Ekaterina; Kostyukevich, Yury; Nikolaev, Eugene

    2017-08-01

    Static harmonization in the Fourier transform ion cyclotron resonance cell improves the resolving power of the cell and prevents dephasing of the ion cloud in the case of any trajectory of the charged particle, not necessarily axisymmetric cyclotron (as opposed to dynamic harmonization). We reveal that the Fourier transform ion cyclotron resonance cell with dynamic harmonization (paracell) is proved to be statically harmonized. The volume of the statically harmonized potential distribution increases with an increase in the number of trap segments.

  13. C-Jun expression in lichen planus, psoriasis, and cutaneous squamous cell carcinoma, an immunohistochemical study.

    Science.gov (United States)

    Abdou, Asmaa Gaber; Marae, Alaa Hassan; Shoeib, Mohammed; Dawood, Ghada; Abouelfath, Enas

    2018-01-01

    The AP-1 transcription factor complex is a key player in regulating inflammatory processes, cell proliferation, differentiation, and cell transformation. The aim of the present study is to investigate C-Jun (one of AP-1complex) expression and its proliferative role in skin samples of lichen planus, psoriasis as common inflammatory skin diseases and squamous cell carcinoma using immunohistochemical method. The present study was carried out on skin biopsies of 15 psoriatic patients, 15 lichen planus patients, 15 SCC, and 15 normal skin biopsies. Nuclear expression of C-Jun was detected in basal and few suprabasal layers of epidermis of normal skin. C-Jun was expressed in the whole epidermal layers of both psoriasis (14/15) and lichen planus (15/15) in addition to its expression in lymphocytic infiltrate in the latter in about half of cases (8/15). C-Jun was also expressed in 93.3% (14/15) of SCC in a percentage lower than that of psoriasis, lichen planus, and normal skin. The percentage of C-Jun expression in SCC was significantly associated with an early stage (p = 0.000), free surgical margins (p = 0.022), and small tumour size (p = 0.003). The marked reduction of C-Jun in SCC in comparison to normal skin and inflammatory skin dermatoses may refer to its tumour suppressor activity. C-Jun expression in SCC carries favourable prognosis. Absence of significant association between C-Jun and Ki-67 either in SCC or inflammatory skin diseases indicates that it does not affect proliferative capacity of cells.

  14. Tropomyosin Receptor Kinase A Expression on Merkel Cell Carcinoma Cells.

    Science.gov (United States)

    Wehkamp, Ulrike; Stern, Sophie; Krüger, Sandra; Hauschild, Axel; Röcken, Christoph; Egberts, Friederike

    2017-11-01

    Merkel cell carcinoma (MCC) is a malignant neuroendocrine skin tumor frequently associated with the Merkel cell polyomavirus. Immune checkpoint therapy showed remarkable results, although not all patients are responsive to this therapy. Anti-tropomyosin receptor kinase A (TrkA)-targeted treatment has shown promising results in several tumor entities. To determine TrkA expression in MCC as a rationale for potential targeted therapy. This case series study investigated the MCC specimens of 55 patients treated at the Department of Dermatology, University Hospital of Schleswig-Holstein, Kiel, Germany, from January 1, 2005, through December 31, 2015. Thirty-nine of the 55 samples were suitable for further histopathologic examination. Expression of TrkA was explored by immunohistochemical analysis. Diagnosis of MCC was confirmed by staining positive for cytokeratin 20 (CK20) and synaptophysin. Expression of TrkA on the tumor cells. Specimens of 39 patients (21 women and 18 men; mean [SD] age, 75.0 [7.8] years) underwent immunohistochemical investigation. Thirty-eight of 38 specimens expressed CK20 and synaptophysin on the MCC tumor cells (100% expression). Merkel cell polyomavirus was detected in 32 of 38 specimens (84%). Tropomyosin receptor kinase A was found in all 36 evaluable specimens on the tumor cells; 34 (94%) showed a weak and 2 (6%) showed a strong cytoplasmic expression. In addition, strongly positive perinuclear dots were observed in 30 of 36 specimens (83%). Tropomyosin receptor kinase A was expressed on MCC tumor cells in 100% of evaluable specimens. This result may lead to the exploration of new targeted treatment options in MCC, especially for patients who do not respond to anti-programmed cell death protein 1 treatment.

  15. Determining Physical Mechanisms of Gene Expression Regulation from Single Cell Gene Expression Data

    OpenAIRE

    Ezer, Daphne; Moignard, Victoria; G?ttgens, Berthold; Adryan, Boris

    2016-01-01

    Many genes are expressed in bursts, which can contribute to cell-to-cell heterogeneity. It is now possible to measure this heterogeneity with high throughput single cell gene expression assays (single cell qPCR and RNA-seq). These experimental approaches generate gene expression distributions which can be used to estimate the kinetic parameters of gene expression bursting, namely the rate that genes turn on, the rate that genes turn off, and the rate of transcription. We construct a complete ...

  16. Feline glycoprotein A repetitions predominant anchors transforming growth factor beta on the surface of activated CD4(+)CD25(+) regulatory T cells and mediates AIDS lentivirus-induced T cell immunodeficiency.

    Science.gov (United States)

    Miller, Michelle M; Fogle, Jonathan E; Ross, Peter; Tompkins, Mary B

    2013-04-01

    Using the feline immunodeficiency virus (FIV) model for AIDS-lentivirus infection, our laboratory has previously demonstrated that T regulatory (Treg) cell-mediated immune T and B cell dysfunction contributes to lentivirus persistence and chronic disease through membrane bound transforming growth factor beta (mTGFb). Studying Treg cells in the context of infection has been problematic as no inducible marker for activated Treg cells had been identified. However, recent reports in human Treg studies have described a novel protein, glycoprotein A repetitions predominant (GARP), as a unique marker of activated human Treg cells that anchors mTGFb. Herein we extend these studies to the feline Treg system, identifying feline GARP and demonstrating that human and feline GARP proteins are homologous in structure, expression pattern, and ability to form a complex with TGFb. We further demonstrate that GARP and TGFb form a complex on the surface of activated Treg cells and that these GARP(+)TGFb(+) Treg cells are highly efficient suppressor cells. Analysis of expression of this Treg activation marker in the FIV-AIDS model reveals an up-regulation of GARP expressing Treg cells during chronic FIV infection. We demonstrate that the GARP(+) Treg cells from FIV-infected cats suppress T helper cells in vivo and that blocking GARP or TGFb eliminates this suppression. These data suggest that GARP is expressed in complex with TGFb on the surface of activated Treg cells and plays an important role in TGFb(+) Treg-mediated T cell immune suppression during lentivirus infection.

  17. Gene expression profiling and candidate gene resequencing identifies pathways and mutations important for malignant transformation caused by leukemogenic fusion genes.

    Science.gov (United States)

    Novak, Rachel L; Harper, David P; Caudell, David; Slape, Christopher; Beachy, Sarah H; Aplan, Peter D

    2012-12-01

    NUP98-HOXD13 (NHD13) and CALM-AF10 (CA10) are oncogenic fusion proteins produced by recurrent chromosomal translocations in patients with acute myeloid leukemia (AML). Transgenic mice that express these fusions develop AML with a long latency and incomplete penetrance, suggesting that collaborating genetic events are required for leukemic transformation. We employed genetic techniques to identify both preleukemic abnormalities in healthy transgenic mice as well as collaborating events leading to leukemic transformation. Candidate gene resequencing revealed that 6 of 27 (22%) CA10 AMLs spontaneously acquired a Ras pathway mutation and 8 of 27 (30%) acquired an Flt3 mutation. Two CA10 AMLs acquired an Flt3 internal-tandem duplication, demonstrating that these mutations can be acquired in murine as well as human AML. Gene expression profiles revealed a marked upregulation of Hox genes, particularly Hoxa5, Hoxa9, and Hoxa10 in both NHD13 and CA10 mice. Furthermore, mir196b, which is embedded within the Hoxa locus, was overexpressed in both CA10 and NHD13 samples. In contrast, the Hox cofactors Meis1 and Pbx3 were differentially expressed; Meis1 was increased in CA10 AMLs but not NHD13 AMLs, whereas Pbx3 was consistently increased in NHD13 but not CA10 AMLs. Silencing of Pbx3 in NHD13 cells led to decreased proliferation, increased apoptosis, and decreased colony formation in vitro, suggesting a previously unexpected role for Pbx3 in leukemic transformation. Published by Elsevier Inc.

  18. Expression of stanniocalcin 1 in thyroid side population cells and thyroid cancer cells.

    Science.gov (United States)

    Hayase, Suguru; Sasaki, Yoshihito; Matsubara, Tsutomu; Seo, Daekwan; Miyakoshi, Masaaki; Murata, Tsubasa; Ozaki, Takashi; Kakudo, Kennichi; Kumamoto, Kensuke; Ylaya, Kris; Cheng, Sheue-yann; Thorgeirsson, Snorri S; Hewitt, Stephen M; Ward, Jerrold M; Kimura, Shioko

    2015-04-01

    Mouse thyroid side population (SP) cells consist of a minor population of mouse thyroid cells that may have multipotent thyroid stem cell characteristics. However the nature of thyroid SP cells remains elusive, particularly in relation to thyroid cancer. Stanniocalcin (STC) 1 and 2 are secreted glycoproteins known to regulate serum calcium and phosphate homeostasis. In recent years, the relationship of STC1/2 expression to cancer has been described in various tissues. Microarray analysis was carried out to determine genes up- and down-regulated in thyroid SP cells as compared with non-SP cells. Among genes up-regulated, stanniocalcin 1 (STC1) was chosen for study because of its expression in various thyroid cells by Western blotting and immunohistochemistry. Gene expression analysis revealed that genes known to be highly expressed in cancer cells and/or involved in cancer invasion/metastasis were markedly up-regulated in SP cells from both intact as well as partial thyroidectomized thyroids. Among these genes, expression of STC1 was found in five human thyroid carcinoma-derived cell lines as revealed by analysis of mRNA and protein, and its expression was inversely correlated with the differentiation status of the cells. Immunohistochemical analysis demonstrated higher expression of STC1 in the thyroid tumor cell line and thyroid tumor tissues from humans and mice. These results suggest that SP cells contain a population of cells that express genes also highly expressed in cancer cells including Stc1, which warrants further study on the role of SP cells and/or STC1 expression in thyroid cancer.

  19. Neural Crest Cells Isolated from the Bone Marrow of Transgenic Mice Express JCV T-Antigen.

    Directory of Open Access Journals (Sweden)

    Jennifer Gordon

    Full Text Available JC virus (JCV, a common human polyomavirus, is the etiological agent of the demyelinating disease, progressive multifocal leukoencephalopathy (PML. In addition to its role in PML, studies have demonstrated the transforming ability of the JCV early protein, T-antigen, and its association with some human cancers. JCV infection occurs in childhood and latent virus is thought to be maintained within the bone marrow, which harbors cells of hematopoietic and non-hematopoietic lineages. Here we show that non-hematopoietic mesenchymal stem cells (MSCs isolated from the bone marrow of JCV T-antigen transgenic mice give rise to JCV T-antigen positive cells when cultured under neural conditions. JCV T-antigen positive cells exhibited neural crest characteristics and demonstrated p75, SOX-10 and nestin positivity. When cultured in conditions typical for mesenchymal cells, a population of T-antigen negative cells, which did not express neural crest markers arose from the MSCs. JCV T-antigen positive cells could be cultured long-term while maintaining their neural crest characteristics. When these cells were induced to differentiate into neural crest derivatives, JCV T-antigen was downregulated in cells differentiating into bone and maintained in glial cells expressing GFAP and S100. We conclude that JCV T-antigen can be stably expressed within a fraction of bone marrow cells differentiating along the neural crest/glial lineage when cultured in vitro. These findings identify a cell population within the bone marrow permissible for JCV early gene expression suggesting the possibility that these cells could support persistent viral infection and thus provide clues toward understanding the role of the bone marrow in JCV latency and reactivation. Further, our data provides an excellent experimental model system for studying the cell-type specificity of JCV T-antigen expression, the role of bone marrow-derived stem cells in the pathogenesis of JCV-related diseases

  20. Rho GTPase expression in human myeloid cells.

    Directory of Open Access Journals (Sweden)

    Suzanne F G van Helden

    Full Text Available Myeloid cells are critical for innate immunity and the initiation of adaptive immunity. Strict regulation of the adhesive and migratory behavior is essential for proper functioning of these cells. Rho GTPases are important regulators of adhesion and migration; however, it is unknown which Rho GTPases are expressed in different myeloid cells. Here, we use a qPCR-based approach to investigate Rho GTPase expression in myeloid cells.We found that the mRNAs encoding Cdc42, RhoQ, Rac1, Rac2, RhoA and RhoC are the most abundant. In addition, RhoG, RhoB, RhoF and RhoV are expressed at low levels or only in specific cell types. More differentiated cells along the monocyte-lineage display lower levels of Cdc42 and RhoV, while RhoC mRNA is more abundant. In addition, the Rho GTPase expression profile changes during dendritic cell maturation with Rac1 being upregulated and Rac2 downregulated. Finally, GM-CSF stimulation, during macrophage and osteoclast differentiation, leads to high expression of Rac2, while M-CSF induces high levels of RhoA, showing that these cytokines induce a distinct pattern. Our data uncover cell type specific modulation of the Rho GTPase expression profile in hematopoietic stem cells and in more differentiated cells of the myeloid lineage.

  1. Caveolin-1 expression in oral lichen planus, dysplastic lesions and squamous cell carcinoma.

    Science.gov (United States)

    Jaafari-Ashkavandi, Zohreh; Aslani, Ehsan

    2017-07-01

    Caveolin-1(Cav-1), the main part of caveolae structure, is supposed to play a role in pathogenesis of many human tumors. Since oral lichen planus (OLP) is considered as a potential premalignant disease, this study evaluated Cav-1 expression in OLP in comparison with benign hyperkeratosis, dysplastic epithelium and oral squamous cell carcinoma (OSCC), to investigate its possible role in pathogenesis and malignant transformation of OLP. In this cross-sectional retrospective study, immunohistochemical expression of Cav-1 in the epithelial component and stroma was evaluated in 81 samples, including 12 cases of hyperkeratosis, 24 OLP, 22 epithelial dysplasia, and 23 OSCC samples. Correlations between Cav-1 expression and clinicopathological variables were evaluated statistically. Positive Cav-1 staining was found in 58% of OLP, 91% of hyperkeratosis, 100% of epithelial dysplasia, and 95% of OSCC samples. OSCC showed the highest Cav-1 expression and OLP had the lowest (P=0.001). The intensity of staining was significantly increased in stepwise manner from OLP to OSCC (P=0.001). Expression of Cav-1 was related to the grade of samples in OSCC and dysplastic samples (P=0.04). Based on the findings, it was concluded that Cav-1 may play a role in the pathogenesis of OLP and carcinogenesis of SCC, but its role in malignant transformation of OLP is not confirmed. Further studies are needed to evaluate its potential therapeutic function in OLP and SCC. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Redistribution of cell cycle by arsenic trioxide is associated with demethylation and expression changes of cell cycle related genes in acute promyelocytic leukemia cell line (NB4).

    Science.gov (United States)

    Hassani, Saeed; Khaleghian, Ali; Ahmadian, Shahin; Alizadeh, Shaban; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Ghaffari, Seyed H

    2018-01-01

    PML-RARα perturbs the normal epigenetic setting, which is essential to oncogenic transformation in acute promyelocytic leukemia (APL). Transcription induction and recruitment of DNA methyltransferases (DNMTs) by PML-RARα and subsequent hypermethylation are components of this perturbation. Arsenic trioxide (ATO), an important drug in APL therapy, concurrent with degradation of PML-RARα induces cell cycle change and apoptosis. How ATO causes cell cycle alteration has remained largely unexplained. Here, we investigated DNA methylation patterns of cell cycle regulatory genes promoters, the effects of ATO on the methylated genes and cell cycle distribution in an APL cell line, NB4. Analysis of promoter methylation status of 22 cell cycle related genes in NB4 revealed that CCND1, CCNE1, CCNF, CDKN1A, GADD45α, and RBL1 genes were methylated 60.7, 84.6, 58.6, 8.7, 33.4, and 73.7%, respectively, that after treatment with 2 μM ATO for 48 h, turn into 0.6, 13.8, 0.1, 6.6, 10.7, and 54.5% methylated. ATO significantly reduced the expression of DNMT1, 3A, and 3B. ATO induced the expression of CCND1, CCNE1, and GADD45α genes, suppressed the expression of CCNF and CDKN1A genes, which were consistent with decreased number of cells in G1 and S phases and increased number of cells in G2/M phase. In conclusion, demethylation and alteration in the expression level of the cell cycle related genes may be possible mechanisms in ATO-induced cell cycle arrest in APL cells. It may suggest that ATO by demethylation of CCND1 and CCNE1 and their transcriptional activation accelerates G1 and S transition into the G2/M cell cycle arrest.

  3. Protoplast isolation, transient transformation of leaf mesophyll protoplasts and improved Agrobacterium-mediated leaf disc infiltration of Phaseolus vulgaris: tools for rapid gene expression analysis.

    Science.gov (United States)

    Nanjareddy, Kalpana; Arthikala, Manoj-Kumar; Blanco, Lourdes; Arellano, Elizabeth S; Lara, Miguel

    2016-06-24

    Phaseolus vulgaris is one of the most extensively studied model legumes in the world. The P. vulgaris genome sequence is available; therefore, the need for an efficient and rapid transformation system is more imperative than ever. The functional characterization of P. vulgaris genes is impeded chiefly due to the non-amenable nature of Phaseolus sp. to stable genetic transformation. Transient transformation systems are convenient and versatile alternatives for rapid gene functional characterization studies. Hence, the present work focuses on standardizing methodologies for protoplast isolation from multiple tissues and transient transformation protocols for rapid gene expression analysis in the recalcitrant grain legume P. vulgaris. Herein, we provide methodologies for the high-throughput isolation of leaf mesophyll-, flower petal-, hypocotyl-, root- and nodule-derived protoplasts from P. vulgaris. The highly efficient polyethylene glycol-mannitol magnesium (PEG-MMG)-mediated transformation of leaf mesophyll protoplasts was optimized using a GUS reporter gene. We used the P. vulgaris SNF1-related protein kinase 1 (PvSnRK1) gene as proof of concept to demonstrate rapid gene functional analysis. An RT-qPCR analysis of protoplasts that had been transformed with PvSnRK1-RNAi and PvSnRK1-OE vectors showed the significant downregulation and ectopic constitutive expression (overexpression), respectively, of the PvSnRK1 transcript. We also demonstrated an improved transient transformation approach, sonication-assisted Agrobacterium-mediated transformation (SAAT), for the leaf disc infiltration of P. vulgaris. Interestingly, this method resulted in a 90 % transformation efficiency and transformed 60-85 % of the cells in a given area of the leaf surface. The constitutive expression of YFP further confirmed the amenability of the system to gene functional characterization studies. We present simple and efficient methodologies for protoplast isolation from multiple P

  4. Expression of blood group I and i active carbohydrate sequences on cultured human and animal cell lines assessed by radioimmunoassays with monoclonal cold agglutinins

    International Nuclear Information System (INIS)

    Childs, R.A.; Kapadia, A.; Feizi, T.

    1980-01-01

    Human monoclonal anti-I and anti-i, reactive with known carbohydrate sequences, have been used as reagents to quantitate (by radioimmunoassay) and visualize (by immunofluorescence) the expression of the various blood group I and i antigenic determinants in a variety of cultured cell lines commonly used in laboratory investigations. It has been shown that the antigens they recognize are widely distributed on the surface of human and animal cell lines, expressed in varying amounts in different cell lines and on individual cells within a given cell line. In two cell lines, a transformation-associated increase in the expression of I antigen was observed. Because of their precise specificity for defined carbohydrate chain domains, these autoantibodies have become valuable reagents in biological chemistry. (orig.) [de

  5. Forced Expression of ZNF143 Restrains Cancer Cell Growth

    International Nuclear Information System (INIS)

    Izumi, Hiroto; Yasuniwa, Yoshihiro; Akiyama, Masaki; Yamaguchi, Takahiro; Kuma, Akihiro; Kitamura, Noriaki; Kohno, Kimitoshi

    2011-01-01

    We previously reported that the transcription factor Zinc Finger Protein 143 (ZNF143) regulates the expression of genes associated with cell cycle and cell division, and that downregulation of ZNF143 induces cell cycle arrest at G2/M. To assess the function of ZNF143 expression in the cell cycle, we established two cells with forced expression of ZNF143 derived from PC3 prostate cancer cell lines. These cell lines overexpress genes associated with cell cycle and cell division, such as polo-like kinase 1 (PLK1), aurora kinase B (AURKB) and some minichromosome maintenance complex components (MCM). However, the doubling time of cells with forced expression of ZNF143 was approximately twice as long as its control counterpart cell line. Analysis following serum starvation and re-seeding showed that PC3 cells were synchronized at G1 in the cell cycle. Also, ZNF143 expression fluctuated, and was at its lowest level in G2/M. However, PC3 cells with forced expression of ZNF143 synchronized at G2/M, and showed lack of cell cycle-dependent fluctuation of nuclear expression of MCM proteins. Furthermore, G2/M population of both cisplatin-resistant PCDP6 cells over-expressing ZNF143 (derived from PC3 cells) and cells with forced expression of ZNF143 was significantly higher than that of each counterpart, and the doubling time of PCDP6 cells is about 2.5 times longer than that of PC3 cells. These data suggested that fluctuations in ZNF143 expression are required both for gene expression associated with cell cycle and for cell division

  6. Forced Expression of ZNF143 Restrains Cancer Cell Growth

    Energy Technology Data Exchange (ETDEWEB)

    Izumi, Hiroto, E-mail: h-izumi@med.uoeh-u.ac.jp; Yasuniwa, Yoshihiro; Akiyama, Masaki; Yamaguchi, Takahiro; Kuma, Akihiro; Kitamura, Noriaki; Kohno, Kimitoshi [Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555 (Japan)

    2011-10-19

    We previously reported that the transcription factor Zinc Finger Protein 143 (ZNF143) regulates the expression of genes associated with cell cycle and cell division, and that downregulation of ZNF143 induces cell cycle arrest at G2/M. To assess the function of ZNF143 expression in the cell cycle, we established two cells with forced expression of ZNF143 derived from PC3 prostate cancer cell lines. These cell lines overexpress genes associated with cell cycle and cell division, such as polo-like kinase 1 (PLK1), aurora kinase B (AURKB) and some minichromosome maintenance complex components (MCM). However, the doubling time of cells with forced expression of ZNF143 was approximately twice as long as its control counterpart cell line. Analysis following serum starvation and re-seeding showed that PC3 cells were synchronized at G1 in the cell cycle. Also, ZNF143 expression fluctuated, and was at its lowest level in G2/M. However, PC3 cells with forced expression of ZNF143 synchronized at G2/M, and showed lack of cell cycle-dependent fluctuation of nuclear expression of MCM proteins. Furthermore, G2/M population of both cisplatin-resistant PCDP6 cells over-expressing ZNF143 (derived from PC3 cells) and cells with forced expression of ZNF143 was significantly higher than that of each counterpart, and the doubling time of PCDP6 cells is about 2.5 times longer than that of PC3 cells. These data suggested that fluctuations in ZNF143 expression are required both for gene expression associated with cell cycle and for cell division.

  7. Forced Expression of ZNF143 Restrains Cancer Cell Growth

    Directory of Open Access Journals (Sweden)

    Kimitoshi Kohno

    2011-10-01

    Full Text Available We previously reported that the transcription factor Zinc Finger Protein 143 (ZNF143 regulates the expression of genes associated with cell cycle and cell division, and that downregulation of ZNF143 induces cell cycle arrest at G2/M. To assess the function of ZNF143 expression in the cell cycle, we established two cells with forced expression of ZNF143 derived from PC3 prostate cancer cell lines. These cell lines overexpress genes associated with cell cycle and cell division, such as polo-like kinase 1 (PLK1, aurora kinase B (AURKB and some minichromosome maintenance complex components (MCM. However, the doubling time of cells with forced expression of ZNF143 was approximately twice as long as its control counterpart cell line. Analysis following serum starvation and re-seeding showed that PC3 cells were synchronized at G1 in the cell cycle. Also, ZNF143 expression fluctuated, and was at its lowest level in G2/M. However, PC3 cells with forced expression of ZNF143 synchronized at G2/M, and showed lack of cell cycle-dependent fluctuation of nuclear expression of MCM proteins. Furthermore, G2/M population of both cisplatin-resistant PCDP6 cells over-expressing ZNF143 (derived from PC3 cells and cells with forced expression of ZNF143 was significantly higher than that of each counterpart, and the doubling time of PCDP6 cells is about 2.5 times longer than that of PC3 cells. These data suggested that fluctuations in ZNF143 expression are required both for gene expression associated with cell cycle and for cell division.

  8. CD25+ B-1a Cells Express Aicda

    Directory of Open Access Journals (Sweden)

    Hiroaki Kaku

    2017-06-01

    Full Text Available B-1a cells are innate-like B-lymphocytes producing natural antibodies. Activation-induced cytidine deaminase (AID, a product of the Aicda gene, plays a central role in class-switch recombination and somatic hypermutation in B cells. Although a role for Aicda in B-1a cells has been suggested on the basis of experiments with knock out (KO mice, whether B-1a cells express Aicda, and if so, which B-1a cell subpopulation expresses Aicda, remains unknown. Here, we demonstrate that B-1 cells express Aicda, but at a level below that expressed by germinal center (GC B cells. We previously reported that B-1a cells can be subdivided based on CD25 expression. We show here that B-1a cell Aicda expression is concentrated in the CD25+ B-1a cell subpopulation. These results suggest the possibility that previous studies of memory B cells identified on the basis of Aicda expression may have inadvertently included an unknown number of CD25+ B-1a cells. Although B-1a cells develop normally in the absence of Aicda, a competitive reconstitution assay reveals enhanced vigor for AID KO B-1a cell bone marrow (BM progenitors, as compared with wild-type BM B-1 cell progenitors. These results suggest that AID inhibits the development of B-1a cells from BM B-1 cell progenitors in a competitive environment.

  9. An efficient protocol for the Agrobacterium-mediated genetic transformation of microalga Chlamydomonas reinhardtii.

    Science.gov (United States)

    Pratheesh, P T; Vineetha, M; Kurup, G Muraleedhara

    2014-06-01

    Algal-based recombinant protein production has gained immense interest in recent years. The development of algal expression system was earlier hindered due to the lack of efficient and cost-effective transformation techniques capable of heterologous gene integration and expression. The recent development of Agrobacterium-mediated genetic transformation method is expected to be the ideal solution for these problems. We have developed an efficient protocol for the Agrobacterium-mediated genetic transformation of microalga Chlamydomonas reinhardtii. Pre-treatment of Agrobacterium in TAP induction medium (pH 5.2) containing 100 μM acetosyringone and 1 mM glycine betaine and infection of Chlamydomonas with the induced Agrobacterium greatly improved transformation frequency. This protocol was found to double the number of transgenic events on selection media compared to that of previous reports. PCR was used successfully to amplify fragments of the hpt and GUS genes from transformed cells, while Southern blot confirmed the integration of GUS gene into the genome of C. reinhardtii. RT-PCR, Northern blot and GUS histochemical analyses confirm GUS gene expression in the transgenic cell lines of Chlamydomonas. This protocol provides a quick, efficient, economical and high-frequency transformation method for microalgae.

  10. Effect of 8-methoxypsoralen-plus ultraviolet light on cell-virus interaction: the transforming infection; effect of PUVA on the transformation of baby hamster kidney cells by polyma virus

    International Nuclear Information System (INIS)

    Morhenn, V.B.; Kaye, J.A.

    1979-01-01

    Pre-treatment of baby hamster kidney (BHK) cells with 8-methoxypsoralen (8-MOP) plus ultraviolet (UV) light enhances the frequency of their transformation by polyoma (Py) virus. Of the doses tested, 0.5 microgram/m1 8-MOP plus 0 . 3 J/cm2 UV-light results in maximal (30-fold) stimulation of viral transformation. 8-MOP alone does not affect viral transformation and UV-light alone causes only a slight increase in the transformation frequency. Thus the drug and light act synergistically in promoting the effect. Treatment of BHK cells with drug plus light without Py infection does not lead to a transformed morphology. A drug-light combination (0 . 01 microgram/m1 8-MOP plus 1 . 2 J/cm2 UV) that inhibits cellular DNA synthesis is 75% of control at 28 hr after treatment results in a 6-fold stimulation of the transformation frequency

  11. TGF-β1 resulting in differential microRNA expression in bovine granulosa cells.

    Science.gov (United States)

    Xu, Yefen; Niu, Jiaqiang; Xi, Guangying; Niu, Xuezhi; Wang, Yuheng; Guo, Ming; Yangzong, Qiangba; Yao, Yilong; Sizhu, Suo Lang; Tian, Jianhui

    2018-07-15

    To explore the expression profile of the cellular miRNAs in bovine ovarian granulosa cells responding to transforming growth factor-β1 (TGF-β1), the effect of TGF-β1 on cell proliferation was firstly investigated by CCK-8 method and the results showed that there was a significant inhibitory effect on bovine granulosa cell proliferation treated with 5/10 ng/mL human recombinant TGF-β1 for 24 h compared to the control (P cells stimulated with or without 10 ng/mL human recombinant TGF-β1. A total of 13,257,248 and 138,726,391 clean reads per library were obtained from TGF-β1 and control groups, respectively. There were 498 and 499 bovine-specific exist miRNAs (exist miRNAs), 627 and 570 conserved known miRNAs (known miRNAs), and 593 and 585 predicted novel miRNAs in TGF-β1 and control groups, respectively. A total of 78 miRNAs with significant differential expression, including 39 up-regulated miRNAs and 39 down-regulated miRNAs were identified in the TGF-β1 group compared with the control. Real-time quantitative PCR analyses of bta-miR-106a and bta-miR-1434-5p showed that their up-expressions were interrupted by SB431542, an inhibitor that blocks TGFβ1/Smad signaling, which supported the sequencing data. GO analysis showed involvement of the predicted genes of the differentially expressed miRNAs in a broad spectrum of cell biological processes, cell components, and molecular functions. KEGG pathway analysis of the predicted miRNA targets further indicated that these differentially expressed miRNAs are involved in various signaling pathways, such as Wnt, MAPK, and TGF-β signaling, which might be involved in follicular development. These results provide valuable information on the composition, expression, and function of miRNAs in bovine granulosa cells responding to TGF-β1, and will aid in understanding the molecular mechanisms of TGF-β1 in granulosa cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Cancer cell detection and classification using transformation invariant template learning methods

    International Nuclear Information System (INIS)

    Talware, Rajendra; Abhyankar, Aditya

    2011-01-01

    In traditional cancer cell detection, pathologists examine biopsies to make diagnostic assessments, largely based on cell morphology and tissue distribution. The process of image acquisition is very much subjective and the pattern undergoes unknown or random transformations during data acquisition (e.g. variation in illumination, orientation, translation and perspective) results in high degree of variability. Transformed Component Analysis (TCA) incorporates a discrete, hidden variable that accounts for transformations and uses the Expectation Maximization (EM) algorithm to jointly extract components and normalize for transformations. Further the TEMPLAR framework developed takes advantage of hierarchical pattern models and adds probabilistic modeling for local transformations. Pattern classification is based on Expectation Maximization algorithm and General Likelihood Ratio Tests (GLRT). Performance of TEMPLAR is certainly improved by defining area of interest on slide a priori. Performance can be further enhanced by making the kernel function adaptive during learning. (author)

  13. Metformin suppresses CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating aryl hydrocarbon receptor expression

    Energy Technology Data Exchange (ETDEWEB)

    Do, Minh Truong; Kim, Hyung Gyun; Tran, Thi Thu Phuong; Khanal, Tilak; Choi, Jae Ho [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of); Chung, Young Chul [Department of Food Science and Culinary, International University of Korea, Jinju (Korea, Republic of); Jeong, Tae Cheon, E-mail: taecheon@ynu.ac.kr [College of Pharmacy, Yeungnam University, Gyeongsan (Korea, Republic of); Jeong, Hye Gwang, E-mail: hgjeong@cnu.ac.kr [Department of Toxicology, College of Pharmacy, Chungnam National University, Daejeon (Korea, Republic of)

    2014-10-01

    Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 and CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer. - Graphical abstract: Schematic of the CYP1A1 and CYP1B1 gene regulation by metformin. - Highlights: • Metformin inhibits CYP1A1 and CYP1B1 expression. • Metformin down-regulates the AhR signaling. • Metformin reduces Sp1 protein expression. • Metformin suppresses TDO expression.

  14. Metformin suppresses CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating aryl hydrocarbon receptor expression

    International Nuclear Information System (INIS)

    Do, Minh Truong; Kim, Hyung Gyun; Tran, Thi Thu Phuong; Khanal, Tilak; Choi, Jae Ho; Chung, Young Chul; Jeong, Tae Cheon; Jeong, Hye Gwang

    2014-01-01

    Induction of cytochrome P450 (CYP) 1A1 and CYP1B1 by environmental xenobiotic chemicals or endogenous ligands through the activation of the aryl hydrocarbon receptor (AhR) has been implicated in a variety of cellular processes related to cancer, such as transformation and tumorigenesis. Here, we investigated the effects of the anti-diabetes drug metformin on expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and inducible conditions. Our results indicated that metformin down-regulated the expression of CYP1A1 and CYP1B1 in breast cancer cells under constitutive and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced conditions. Down-regulation of AhR expression was required for metformin-mediated decreases in CYP1A1 and CYP1B1 expression, and the metformin-mediated CYP1A1 and CYP1B1 reduction is irrelevant to estrogen receptor α (ERα) signaling. Furthermore, we found that metformin markedly down-regulated Sp1 protein levels in breast cancer cells. The use of genetic and pharmacological tools revealed that metformin-mediated down-regulation of AhR expression was mediated through the reduction of Sp1 protein. Metformin inhibited endogenous AhR ligand-induced CYP1A1 and CYP1B1 expression by suppressing tryptophan-2,3-dioxygenase (TDO) expression in MCF-7 cells. Finally, metformin inhibits TDO expression through a down-regulation of Sp1 and glucocorticoid receptor (GR) protein levels. Our findings demonstrate that metformin reduces CYP1A1 and CYP1B1 expression in breast cancer cells by down-regulating AhR signaling. Metformin would be able to act as a potential chemopreventive agent against CYP1A1 and CYP1B1-mediated carcinogenesis and development of cancer. - Graphical abstract: Schematic of the CYP1A1 and CYP1B1 gene regulation by metformin. - Highlights: • Metformin inhibits CYP1A1 and CYP1B1 expression. • Metformin down-regulates the AhR signaling. • Metformin reduces Sp1 protein expression. • Metformin suppresses TDO expression

  15. Consumer transformation: Cosmetic surgery as the expression of consumer freedom or as a marketing imperative?

    OpenAIRE

    Hill, B.

    2016-01-01

    McCracken’s analysis of identity construction in contemporary culture sees the drive to transform oneself as the expression of consumer agency and individual freedom. Transformation is accessible through cosmetic surgery, enabling consumers with funds to purchase a ‘whole new me’. This consumer is an active participant in the transformation process, not content with observing beauty but actively engaged in the creative construction of new improved selves. In doing so, they have “mastered the ...

  16. In vivo expression of a Cicer arietinum B-galactosidase in potato tubers leads to a reduction of the Galactan side-chains in cell wall pectin

    NARCIS (Netherlands)

    Martin, I.; Dopico, B.; Munoz, F.J.; Esteban, R.; Oomen, R.J.F.J.; Driouich, A.; Vincken, J.P.; Visser, R.G.F.; Labrador, E.

    2005-01-01

    We report the generation of Solanum tuberosum transformants expressing Cicer arietinum ßIII-Gal. ßIII-Gal is a ß-galactosidase able to degrade cell wall pectins during cell wall loosening that occurs prior to cell elongation. cDNA corresponding to the gene encoding this protein was identified among

  17. A novel role of EMMPRIN/CD147 in transformation of quiescent fibroblasts to cancer-associated fibroblasts by breast cancer cells

    Science.gov (United States)

    Xu, Jing; Lu, Yang; Qiu, Songbo; Chen, Zhi-Nan; Fan, Zhen

    2013-01-01

    We tested the novel hypothesis that EMMPRIN/CD147, a transmembrane glycoprotein overexpressed in breast cancer cells, has a previously unknown role in transforming fibroblasts to cancer-associated fibroblasts, and that cancer-associated fibroblasts in turn induce epithelial-to-mesenchymal transition of breast cancer cells. Co-culture of fibroblasts with breast cancer cells or treatment of fibroblasts with breast cancer cell conditioned culture medium or recombinant EMMPRIN/CD147 induced expression of α-SMA in the fibroblasts in an EMMPRIN/CD147-dependent manner and promoted epithelial-to-mesenchymal transition of breast cancer cells and enhanced cell migration potential. These findings support a novel role of EMMPRIN/CD147 in regulating the interaction between cancer and stroma. PMID:23474495

  18. Mesenchymal stromal cells reverse hypoxia-mediated suppression of α-smooth muscle actin expression in human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Faulknor, Renea A.; Olekson, Melissa A.; Nativ, Nir I.; Ghodbane, Mehdi; Gray, Andrea J.; Berthiaume, François, E-mail: fberthia@rci.rutgers.edu

    2015-02-27

    During wound healing, fibroblasts deposit extracellular matrix that guides angiogenesis and supports the migration and proliferation of cells that eventually form the scar. They also promote wound closure via differentiation into α-smooth muscle actin (SMA)-expressing myofibroblasts, which cause wound contraction. Low oxygen tension typical of chronic nonhealing wounds inhibits fibroblast collagen production and differentiation. It has been suggested that hypoxic mesenchymal stromal cells (MSCs) secrete factors that promote wound healing in animal models; however, it is unclear whether these factors are equally effective on the target cells in a hypoxic wound environment. Here we investigated the impact of MSC-derived soluble factors on the function of fibroblasts cultured in hypoxic fibroblast-populated collagen lattices (FPCLs). Hypoxia alone significantly decreased FPCL contraction and α-SMA expression. MSC-conditioned medium restored hypoxic FPCL contraction and α-SMA expression to levels similar to normoxic FPCLs. (SB431542), an inhibitor of transforming growth factor-β{sub 1} (TGF-β{sub 1})-mediated signaling, blocked most of the MSC effect on FPCL contraction, while exogenous TGF-β{sub 1} at levels similar to that secreted by MSCs reproduced the MSC effect. These results suggest that TGF-β{sub 1} is a major paracrine signal secreted by MSCs that can restore fibroblast functions relevant to the wound healing process and that are impaired in hypoxia. - Highlights: • Fibroblasts were cultured in collagen lattices (FPCLs) as model contracting wounds. • Hypoxia decreased FPCL contraction and fibroblast α-smooth muscle actin expression. • Mesenchymal stromal cells (MSCs) restored function of hypoxic fibroblasts. • MSCs regulate fibroblast function mainly via secreted transforming growth factor-β{sub 1}.

  19. Mesenchymal stromal cells reverse hypoxia-mediated suppression of α-smooth muscle actin expression in human dermal fibroblasts

    International Nuclear Information System (INIS)

    Faulknor, Renea A.; Olekson, Melissa A.; Nativ, Nir I.; Ghodbane, Mehdi; Gray, Andrea J.; Berthiaume, François

    2015-01-01

    During wound healing, fibroblasts deposit extracellular matrix that guides angiogenesis and supports the migration and proliferation of cells that eventually form the scar. They also promote wound closure via differentiation into α-smooth muscle actin (SMA)-expressing myofibroblasts, which cause wound contraction. Low oxygen tension typical of chronic nonhealing wounds inhibits fibroblast collagen production and differentiation. It has been suggested that hypoxic mesenchymal stromal cells (MSCs) secrete factors that promote wound healing in animal models; however, it is unclear whether these factors are equally effective on the target cells in a hypoxic wound environment. Here we investigated the impact of MSC-derived soluble factors on the function of fibroblasts cultured in hypoxic fibroblast-populated collagen lattices (FPCLs). Hypoxia alone significantly decreased FPCL contraction and α-SMA expression. MSC-conditioned medium restored hypoxic FPCL contraction and α-SMA expression to levels similar to normoxic FPCLs. (SB431542), an inhibitor of transforming growth factor-β 1 (TGF-β 1 )-mediated signaling, blocked most of the MSC effect on FPCL contraction, while exogenous TGF-β 1 at levels similar to that secreted by MSCs reproduced the MSC effect. These results suggest that TGF-β 1 is a major paracrine signal secreted by MSCs that can restore fibroblast functions relevant to the wound healing process and that are impaired in hypoxia. - Highlights: • Fibroblasts were cultured in collagen lattices (FPCLs) as model contracting wounds. • Hypoxia decreased FPCL contraction and fibroblast α-smooth muscle actin expression. • Mesenchymal stromal cells (MSCs) restored function of hypoxic fibroblasts. • MSCs regulate fibroblast function mainly via secreted transforming growth factor-β 1

  20. Dissecting the expression of EEF1A1/2 genes in human prostate cancer cells: the potential of EEF1A2 as a hallmark for prostate transformation and progression.

    Science.gov (United States)

    Scaggiante, B; Dapas, B; Bonin, S; Grassi, M; Zennaro, C; Farra, R; Cristiano, L; Siracusano, S; Zanconati, F; Giansante, C; Grassi, G

    2012-01-03

    In prostate adenocarcinoma, the dissection of the expression behaviour of the eukaryotic elongation factors (eEF1A1/2) has not yet fully elucidated. The EEF1A1/A2 expressions were investigated by real-time PCR, western blotting (cytoplasmic and cytoskeletal/nuclear-enriched fractions) and immunofluorescence in the androgen-responsive LNCaP and the non-responsive DU-145 and PC-3 cells, displaying a low, moderate and high aggressive phenotype, respectively. Targeted experiments were also conducted in the androgen-responsive 22Rv1, a cell line marking the progression towards androgen-refractory tumour. The non-tumourigenic prostate PZHPV-7 cell line was the control. Compared with PZHPV-7, cancer cells showed no major variations in EEF1A1 mRNA; eEF1A1 protein increased only in cytoskeletal/nuclear fraction. On the contrary, a significant rise of EEF1A2 mRNA and protein were found, with the highest levels detected in LNCaP. Eukaryotic elongation factor 1A2 immunostaining confirmed the western blotting results. Pilot evaluation in archive prostate tissues showed the presence of EEF1A2 mRNA in near all neoplastic and perineoplastic but not in normal samples or in benign adenoma; in contrast, EEF1A1 mRNA was everywhere detectable. Eukaryotic elongation factor 1A2 switch-on, observed in cultured tumour prostate cells and in human prostate tumour samples, may represent a feature of prostate cancer; in contrast, a minor involvement is assigned to EEF1A1. These observations suggest to consider EEF1A2 as a marker for prostate cell transformation and/or possibly as a hallmark of cancer progression.

  1. Repair mechanisms in radiation-induced cell transformation

    International Nuclear Information System (INIS)

    Elkind, M.M.; Han, A.; Hill, C.K.; Buonaguro, F.

    1983-01-01

    Our data with both low- and high-LET radiations are qualitatively similar to results obtained in vivo. This is evident, for example, in the reductions in cell transformation for protracted exposures of γ-rays. The consistencies between our results with cells and the data of others with animals lend support to Gray's hypothesis that tumorigenesis is the net effect of a low probability inductive process, and a high probability killing process. An important prediction can be made when spontaneous frequency is appreciable (e.g., 43% in the case of reticulum cell sarcoma in RFM mice). For small doses, tumorigenesis would drop provided that: (a) the cells responsible for the spontaneous incidence are present at the time of exposure; and (b) the progenitor cells of the tumor are not resistant to cell killing

  2. During development intense Sox2 expression marks not only Prox1-expressing taste bud cell but also perigemmal cell lineages.

    Science.gov (United States)

    Nakayama, Ayumi; Miura, Hirohito; Ooki, Makoto; Harada, Shuitsu

    2015-03-01

    Sox2 is proposed to regulate the differentiation of bipotential progenitor cells into taste bud cells. However, detailed expression of Sox2 remains unclear. In this report, Sox2 expression during taste bud development in the fungiform (FF), circumvallate (CV) and soft palate (SP) areas is examined together with Prox1. First, we immunohistochemically checked Prox1 expression in adults and found that almost all taste bud cells are Prox1-positive. During FF development, intense Sox2 expression was restricted to taste bud primordia expressing Prox1 at E12.5. However, at E14.5, Sox2 was intensely expressed outside the developing taste buds resolving to perigemmal Sox2 expression in adults. In the SP, at E14.5, taste bud primordia emerged as Prox1-expressing cell clusters. However, intense Sox2 expression was not restricted to taste bud primordia but was detected widely in the epithelium. During development, Sox2 expression outside developing taste buds was generally down-regulated but was retained in the perigemmal region similarly to that in the FF. In the CV, the initial stage of taste bud development remained unclear because of the lack of taste bud primordia comparable to that in the FF and SP. Here, we show that Prox1-expressing cells appear in the apical epithelium at E12.5, in the inner trench wall at E17.5 and in the outer trench wall at E18.5. Sox2 was again not restricted to developing taste bud cells expressing Prox1 during CV development. The expression patterns support that Sox2 does not serve as a cell fate selector between taste bud cells and surrounding keratinocytes but rather may contribute to them both.

  3. Decorin expression in quiescent myogenic cells

    International Nuclear Information System (INIS)

    Nishimura, Takanori; Nozu, Kenjiro; Kishioka, Yasuhiro; Wakamatsu, Jun-ichi; Hattori, Akihito

    2008-01-01

    Satellite cells are quiescent muscle stem cells that promote postnatal muscle growth and repair. When satellite cells are activated by myotrauma, they proliferate, migrate, differentiate, and ultimately fuse to existing myofibers. The remainder of these cells do not differentiate, but instead return to quiescence and remain in a quiescent state until activation begins the process again. This ability to maintain their own population is important for skeletal muscle to maintain the capability to repair during postnatal life. However, the mechanisms by which satellite cells return to quiescence and maintain the quiescent state are still unclear. Here, we demonstrated that decorin mRNA expression was high in cell cultures containing a higher ratio of quiescent satellite cells when satellite cells were stimulated with various concentrations of hepatocyte growth factor. This result suggests that quiescent satellite cells express decorin at a high level compared to activated satellite cells. Furthermore, we examined the expression of decorin in reserve cells, which were undifferentiated myoblasts remaining after induction of differentiation by serum-deprivation. Decorin mRNA levels in reserve cells were higher than those in differentiated myotubes and growing myoblasts. These results suggest that decorin participates in the quiescence of myogenic cells

  4. Modulation of cellular phosphoprotein profiles in transformation and redifferentiation of murine and embryonic fibroblastic cells

    International Nuclear Information System (INIS)

    Chakrabarty, Subhas; Brattain, M.G.

    1985-01-01

    Cellular phosphoprotein profiles from normal mouse embryonic fibroblast AKR-2B cells were compared to those of their permanently, chemically transformed malignant counterparts AKR-MCA cells, and AKR-2B cells reversibly transformed by transforming growth factor (AKR-TGF). Similar 32 P-phosphorylation profiles were observed for both the AKR-TGF and AKR-MCA cells which were distinct from that of the normal AKR-2B cells. Dimethylformamide (DMF)-induced differentiation of the AKR-MCA cells resulted in restoration of the normal AKR-2B phosphorylation profile to the malignant AKR-MCA cells. (author)

  5. PHTS, a novel putative tumor suppressor, is involved in the transformation reversion of HeLaHF cells independently of the p53 pathway

    International Nuclear Information System (INIS)

    Yu Dehua; Fan, Wufang; Liu, Guohong; Nguy, Vivian; Chatterton, Jon E.; Long Shilong; Ke, Ning; Meyhack, Bernd; Bruengger, Adrian; Brachat, Arndt; Wong-Staal, Flossie; Li, Qi-Xiang

    2006-01-01

    HeLaHF is a non-transformed revertant of HeLa cells, likely resulting from the activation of a putative tumor suppressor(s). p53 protein was stabilized in this revertant and reactivated for certain transactivation functions. Although p53 stabilization has not conclusively been linked to the reversion, it is clear that the genes in p53 pathway are involved. The present study confirms the direct role of p53 in HeLaHF reversion by demonstrating that RNAi-mediated p53 silencing partially restores anchorage-independent growth potential of the revertant through the suppression of anoikis. In addition, we identified a novel gene, named PHTS, with putative tumor suppressor properties, and showed that this gene is also involved in HeLaHF reversion independently of the p53 pathway. Expression profiling revealed that PHTS is one of the genes that is up-regulated in HeLaHF but not in HeLa. It encodes a putative protein with CD59-like domains. RNAi-mediated PHTS silencing resulted in the partial restoration of transformation (anchorage-independent growth) in HeLaHF cells, similar to that of p53 gene silencing, implying its tumor suppressor effect. However, the observed increased transformation potential by PHTS silencing appears to be due to an increased anchorage-independent proliferation rate rather than suppression of anoikis, unlike the effect of p53 silencing. p53 silencing did not affect PHTS gene expression, and vice versa, suggesting PHTS may function in a new and p53-independent tumor suppressor pathway. Furthermore, over-expression of PHTS in different cancer cell lines, in addition to HeLa, reduces cell growth likely via induced apoptosis, confirming the broad PHTS tumor suppressor properties

  6. One pyrimidine dimer inactivates expression of a transfected gene in xeroderma pigmentosum cells

    International Nuclear Information System (INIS)

    Protic-Sabljic, M.; Kraemer, K.H.

    1985-01-01

    The authors have developed a host cell reactivation assay of DNA repair utilizing UV-treated plasmid vectors. The assay primarily reflects cellular repair of transcriptional activity of damaged DNA measured indirectly as enzyme activity of the transfected genes. They studied three plasmids (pSV2cat, 5020 base pairs; pSV2catSVgpt, 7268 base pairs; and pRSVcat, 5027 base pairs) with different sizes and promoters carrying the bacterial cat gene (CAT, chloramphenicol acetyltransferase) in a construction that permits cat expression in human cells. All human simian virus 40-transformed cells studied expressed high levels of the transfected cat gene. UV treatment of the plasmids prior to transfection resulted in differential decrease in CAT activity in different cell lines. With pSV2catSVgpt, UV inactivation of CAT expression was greater in the xeroderma pigmentosum group A and D lines than in the other human cell lines tested. The D 0 of the CAT inactivation curve was 50 J X m-2 for pSV2cat and for pRSVcat in the xeroderma pigmentosum group A cells. The similarity of the D0 data in the xeroderma pigmentosum group A cells for three plasmids of different size and promoters implies they all have similar UV-inactivation target size. UV-induced pyrimidine dimer formation in the plasmids was quantified by assay of the number of UV-induced T4 endonuclease V-sensitive sites. In the most sensitive xeroderma pigmentosum cells, with all three plasmids, one UV-induced pyrimidine dimer inactivates a target of about 2 kilobases, close to the size of the putative CAT mRNA

  7. Highly efficient biodiesel production by a whole-cell biocatalyst employing a system with high lipase expression in Aspergillus oryzae

    Energy Technology Data Exchange (ETDEWEB)

    Takaya, Tomohiro; Koda, Risa; Adachi, Daisuke; Ogino, Chiaki; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering; Nakashima, Kazunori [Kobe Univ. (Japan). Organization of Advanced Science and Technology; Wada, Junpei; Bogaki, Takayuki [Ozeki Co., Nishinomiya-shi, Hyogo (Japan)

    2011-05-15

    In the present study, a system with high lipase expression in Aspergillus oryzae was developed using an improved enolase promoter (P-enoA124) and the 5{sup '} untranslated region of a heat-shock protein (Hsp-UTR). P-enoA142 enhanced the transcriptional level of a heterologous lipase gene and Hsp-UTR improved its translational efficiency. Fusarium heterosporum lipase (FHL) was inserted into a pSENSU-FHL expression vector harboring P-enoA142 and Hsp-UTR and was transformed into an A. oryzae NS4 strain. Transformants possessing pSENSU-FHL in single (pSENSU-FHL1) and double copies (pSENSU-FHL2) were selected to evaluate the lipase activity of the whole-cell biocatalyst. The two strains, pSENSU-FHL1 and 2, showed excellent lipase activity in hydrolysis compared with the strain transformed with conventional expression vector pNAN8142-FHL. Furthermore, by using pSENSU-FHL2, methanolysis could proceed much more effectively without deactivation, which allowed a swift addition of methanol to the reaction mixture, thereby reducing reaction time. (orig.)

  8. Helios expression in regulatory T cells promotes immunosuppression, angiogenesis and the growth of leukemia cells in pediatric acute lymphoblastic leukemia.

    Science.gov (United States)

    Li, Xue; Li, Dong; Huang, Xiaoyang; Zhou, Panpan; Shi, Qing; Zhang, Bing; Ju, Xiuli

    2018-04-01

    Regulatory T cells (Tregs) characterized by the transcription factor forkhead box P3 (FoxP3) are crucial for maintaining immune tolerance and preventing autoimmunity. However, FoxP3 does not function alone and Helios is considered a potential candidate for defining Treg subsets. In this study, we investigated the expression and function of Helios for identifying Tregs in childhood precursor B-cell acute lymphoblastic leukemia (pre-B ALL). Our results demonstrated that patients with pre-B ALL had a higher percentage of Helios + FoxP3 + CD4 + Tregs. And there was a positive correlation between the expression of Helios and the suppressive function of Tregs, the risk gradation of ALL. Helios in combination with CD4 and FoxP3 may be an effective way to detect functional Tregs in pre-B ALL by promoting the secretion of transforming growth factor (TGF)-β1. Furthermore, Helios + Tregs could regulate angiogenesis in the BM niche of pre-B ALL via the VEGFA/VEGFR2 pathway. We also found Helios + Tregs decreased apoptosis rate of nalm-6 cells by up-regulating the expression of anti-apoptosis protein Bcl-2. In summary, these data strongly imply the physiological importance of Helios expression in Tregs, and suggest that the manipulation of Helios may serve as a novel strategy for cancer immunotherapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Resveratrol mediated cell death in cigarette smoke transformed breast epithelial cells is through induction of p21Waf1/Cip1 and inhibition of long patch base excision repair pathway

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, Purusottam; Satapathy, Shakti Ranjan; Das, Dipon; Siddharth, Sumit [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar, Orissa 751024 (India); Choudhuri, Tathagata [Institute of Life Sciences, Nalco Square, Bhubaneswar, Orissa 751023 (India); Department of Biotechnology, Visva Bharati University, Santiniketan, West Bengal (India); Kundu, Chanakya Nath, E-mail: cnkundu@gmail.com [Cancer Biology Division, KIIT School of Biotechnology, KIIT University, Campus-11, Patia, Bhubaneswar