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Danny R Welch - One of the best experts on this subject based on the ideXlab platform.

  • melanoma metastasis suppression by Chromosome 6 evidence for a pathway regulated by crsp3 and txnip
    Cancer Research, 2003
    Co-Authors: Steven F Goldberg, Mary Beth Miele, Naohito Hatta, Minoru Takata, Carrie Paquettestraub, Leonard P Freedman, Danny R Welch
    Abstract:

    Loss of genetic material on Chromosome 6 has been associated with progression of human melanomas. We showed previously that introducing Chromosome 6 into metastatic human melanoma cell lines suppresses metastasis without affecting the ability of the hybrids to form progressively growing tumors. By subtractive hybridization comparing nonmetastatic Chromosome 6-containing (neo6/C8161) versus parental (C8161) metastatic cells, the KISS1 metastasis suppressor gene was isolated. However, KISS1 mapped to Chromosome 1q32. To identify upstream regulator(s) of (and downstream effectors of) KISS1, microarray hybridization comparing C8161 and neo6/C8161 variants was performed. TXNIP/VDUP1, a thioredoxin-binding protein, was expressed more highly in neo6/C8161 and in nonmetastatic melanomas. Increased TXNIP expression inhibited metastasis and up-regulated KISS1. Surprisingly, TXNIP also mapped to Chromosome 1q. PCR karyotyping that refined the region on Chromosome 6 identified CRSP3/DRIP130, a transcriptional coactivator, as a metastasis suppressor. CRSP3 transfectant cells had up-regulated KISS1 and TXNIP expression and were suppressed for metastasis. Quantitative real-time reverse-transcription PCR of clinical melanoma samples showed that loss of CRSP3 expression correlated with decreased KISS1 expression and increased metastasis. Thus, we implicated a specific gene on Chromosome 6 in the etiology of melanoma metastasis and identified potential up-stream regulators of KISS1 and TXNIP.

  • suppression of human melanoma metastasis following introduction of Chromosome 6 is independent of nme1 nm23
    Clinical & Experimental Metastasis, 1997
    Co-Authors: Mary Beth Miele, Abel De La Rosa, Jeong Hyung Lee, Deana J Hicks, John U Dennis, Patricia S Steeg, Danny R Welch
    Abstract:

    Metastasis is suppressed more than 95% following microcell-mediated transfer of a single copy of neomycin-tagged human Chromosome 6 (neo6) into the human melanoma cell lines C8161 and MelJuSo. Concomitant with metastasis suppression is upregulation of NME1 (Nm23-H1) mRNA and protein expression. The purposes of this study were to determine whether NME1 expression was responsible for metastasis suppression in neo6/melanoma hybrids, and whether genes on Chromosome 6 regulate NME1. Using neo6/C8161 cells, transfection of CAT reporter constructs linked to the NME1 promoter failed to consistently induce CAT. Therefore, it does not appear that genes on Chromosome 6 directly control transcription of NME1. Transfection and overexpression of NME1 in MelJuSo, under the control of the CMV promoter, resulted in 40-80% inhibition of lung metastasis following i.v. inoculation of 2´10 cells. Only one transfectant of C8161 subclone 9 (C8161cl.9) cells was suppressed for metastasis. Control transfections with pCMVneo or pSV2neo did not suppress metastasis in either cell line. Taken together, these data suggest that NME1 can reduce metastatic potential of some human melanoma cells; but, this inhibitory activity appears to be independent of the metastasis suppression following introduction of Chromosome 6 into C8161 and MelJuSo human melanoma cell lines.

  • suppression of human melanoma metastasis by introduction of Chromosome 6 may be partially due to inhibition of motility but not to inhibition of invasion
    Biochemical and Biophysical Research Communications, 1995
    Co-Authors: Jun You, Mary E Miele, Cheng Dong, Danny R Welch
    Abstract:

    Active cellular motility and invasion play essential roles in metastasis. Introduction of normal, neo-tagged human Chromosome 6 (neo6) into highly metastatic human melanoma cell line C8161 results in complete suppression of metastasis in vivo. To understand the mechanism by which metastasis was inhibited in neo6/C8161 hybrids, two in vitro assays, pseudopod protrusion and Membrane Invasion Culture System, were used to measure motility and invasion, respectively. neo6/C8161 hybrids are much less motile although they remained invasive, indicating that a metastasis-suppressor gene(s) on human Chromosome 6 may regulate cellular motility, thereby inhibiting metastasis.

  • microcell mediated transfer of Chromosome 6 into metastatic human c8161 melanoma cells suppresses metastasis but does not inhibit tumorigenicity
    Oncogene, 1994
    Co-Authors: Danny R Welch, Eric J Stanbridge, Pengchin Chen, Mary E Miele, Carl T Mcgary, Jill M Bower, Bernard E Weissman
    Abstract:

    Structural alterations of Chromosome 6, including del(6q), are often associated with metastatic melanoma; therefore, we hypothesized that a metastasis-suppressor gene could be coded on human Chromosome 6. Highly metastatic C8161 human malignant melanoma cells exhibit chromosomal changes typical of late-stage melanomas. Using microcell-mediated Chromosome transfer, a copy of a normal human Chromosome 6 was introduced into C8161. Three randomly selected hybrid clones (neo6/C8161.1, neo6/C8161.2 and neo6/C8161.3) were assayed for metastasis in athymic nude mice. All controls - parental C8161 cells, randomly-selected single cell clones, neo-transfected cell clones, neo11/C8161.2 and neo11/C8161.3 - were tumorigenic (270/272 mice) and metastatic (208/272 mice). neo6/C8161 hybrid cells were still tumorigenic (91/93 mice) but were not metastatic (0/195 mice). The presence of the added Chromosomes was verified in cultured and tumor cells by amplification of polymorphic (CA)n markers using PCR-RFLP. The neo6/C8161 hybrids display growth and morphological patterns of more differentiated cells than C8161. In Northern blot analysis an inverse relationship between metastatic ability and metastasis-suppressor gene, nm23-H1, expression is observed - with clone neo6/C8161.1 expressing the highest level of nm23 transcripts, neo6/C8161.2 and neo6/C8161.3 expressing intermediate levels, and barely detectable levels are seen in C8161. Collectively, these results suggest that a malignant melanoma metastasis-regulatory gene may be located on human Chromosome 6. These results further demonstrate that tumorigenicity and metastatic ability are distinct phenotypes.

Jeffrey M Trent - One of the best experts on this subject based on the ideXlab platform.

  • isolation and characterization of genes associated with Chromosome 6 mediated tumor suppression in human malignant melanoma
    Oncogene, 1996
    Co-Authors: Yan A Su, Paul S Meltzer, Jeffrey M Trent
    Abstract:

    : Melanocytic transformation is thought to occur by the sequential accumulation of genetic alterations. Evidence implicating human Chromosomes as a site for a gene(s) involved in melanoma suppression comes from studies of LOH [loss of heterozygosity], cytogenetics and biologic reversion of tumorigenicity following the introduction of a normal Chromosome 6 by microcell-mediated Chromosome transfer (Trent et al., 1990). Using a tumorigenic melanoma cell line (UACC 903) and a Chromosome-6 suppressed melanoma subline [UACC 903 (+6)], we have isolated a series of genes uniquely expressed in the suppressed subline. A modified PCR-based cDNA subtraction technique was used to generate subtracted cDNA sublibraries for both the parental and (+6) suppressed cells. A total of 32 randomly selected clones from the suppressed sublibrary were isolated and examined, with 24 detecting a transcript by Northern analysis. Of these 24 clones, 21 (88%) demonstrated elevated expressed by Northern analysis in the suppressed subline relative to the tumorigenic parental cell line. In 6/21 differentially expressed clones (29%), expression was exclusive to the suppressed subline. Partial sequence analysis and database searching of these clones indicated that 5/6 were novel with one representing a previously characterized gene. Chromosomal localization of the five novel clones was performed following PCR amplification of a human/rodent somatic cell hybrid mapping panel or fluorescent in situ hybridization. One cDNA (termed AIM1) was localized to a band-region of Chromosome 6 frequently deleted in melanomas (6q21). This novel approach should facilitate the identification of genes whose expression is causally related to the suppressed phenotype.

  • coverage of Chromosome 6 by Chromosome microdissection generation of 14 subregion specific probes
    Human Genetics, 1995
    Co-Authors: Xin Yuan Guan, Paul S Meltzer, Ann C Burgess, Jeffrey M Trent
    Abstract:

    Human Chromosome 6 has been subdivided by Chromosome microdissection into 14 unique regions. Following microdissection, polymerase chain reaction (PCR) amplification of dissected DNA was performed using a universal primer to generate subregion-specific probes that provided complete coverage of Chromosome 6. All 16 microdissections have been regionally assigned along Chromosome 6 by fluorescence in situ hybridization (FISH) using biotin-labeled dissected DNA hybridized to G-banded normal metaphase Chromosomes. These probes can be used as region-specific paints to generate unique “bar codes” and for analysis of Chromosome alterations involving Chromosome 6 that are unidentifiable by conventional banding analysis.

  • regional assignment by hybrid mapping of 36 expressed sequence tags ests on human Chromosome 6
    Genomics, 1995
    Co-Authors: Mihael H Polymeropoulos, George J Pappas, John M Boyle, Jeffrey M Trent
    Abstract:

    We have determined the regional Chromosome assignment of 36 cDNAs from infant brain libraries by assessing the concordant segregation of PCR products using a human-rodent hybrid mapping panel that subdivides Chromosome 6 into 15 regions. These mapped sequences serve as markers for the physical and expression maps of Chromosome 6, as well as candidate genes for various disease loci. Sequence analysis has identified putative functions and motifs for some of these genes.

  • generation and molecular cytogenetic characterization of a radiation reduction hybrid panel for human Chromosome 6
    Cytogenetic and Genome Research, 1995
    Co-Authors: G J Pappas, Ann C Burgess, E Thompson, A Greenwood, Jeffrey M Trent
    Abstract:

    A neoR marked Chromosome-6 containing hybrid (D113 JA) was used to generate a panel of 15 radiation-reduced hybrid cell lines. The panel was constructed by irradiating microcells isolated f

  • generation and characterization of a human Chromosome 6 specific hncdna library from a somatic cell hybrid
    Cytogenetic and Genome Research, 1995
    Co-Authors: Klaus Piontek, Jeffrey M Trent, Paul S Meltzer, Hanswerner Muller, Ulrike Fischer, E Gotten, Mark A Batzer, Eckart Meese
    Abstract:

    Chromosome specific cDNA libraries are a useful source of candidate genes for disorders which have been linked to particular Chromosomes. Here, we report the generation of a cDNA library made from a somatic cell hybrid retaining Chromosome 6 as its only human component. In order to ascertain the chromosomal location of cDNAs the library was amplified by inter-Alu-PCR and used as probe for competitive in situ suppression (CISS). To identify human specific cDNA clones the library was screened with PD39, a highly human specific Alu consensus probe. Out of 350,000 clones 360 were found to hybridize with PD39. Nucleotide sequences were determined for 40 clones with inserts larger than 500 basepairs (bp) and a sequence comparison was performed at the National Center for Biotechnology Information using BLASTN. One clone was shown to be identical to Manganese Superoxide Dismutase (MnSOD/SOD2) which has previously been assigned to Chromosome 6q25. Localization of 11 clones was determined using PCR and clone-specific primer pairs on a hybrid mapping panel DNA set. Two PCR-localized clones and five additional clones were localized by fluorescence in situ hybridization. Transcripts for five clones were identified by RT-PCR. The generation of Chromosome 6-specific hncDNAs from a somatic cell hybrid should aid in the identification of disease-associated genes localized on this Chromosome.

Isabella Borg - One of the best experts on this subject based on the ideXlab platform.

  • molecular cytogenetic characterisation of a novel de novo ring Chromosome 6 involving a terminal 6p deletion and terminal 6q duplication in the different arms of the same Chromosome
    Molecular Cytogenetics, 2017
    Co-Authors: Nikolai P Pace, Frideriki Maggouta, Melissa Twigden, Isabella Borg
    Abstract:

    Ring Chromosome 6 is a rare sporadic chromosomal abnormality, associated with extreme variability in clinical phenotypes. Most ring Chromosomes are known to have deletions on one or both chromosomal arms. Here, we report an atypical and unique ring Chromosome 6 involving both a distal deletion and a distal duplication on the different arms of the same Chromosome. In a patient with intellectual disability, short stature, microcephaly, facial dysmorphology, congenital heart defects and renovascular disease, a ring Chromosome 6 was characterised using array-CGH and dual-colour FISH. The de-novo ring Chromosome 6 involved a 1.8 Mb terminal deletion in the distal short arm and a 2.5 Mb duplication in the distal long arm of the same Chromosome 6. This results in monosomy for the region 6pter to 6p25.3 and trisomy for the region 6q27 to 6qter. Analysis of genes in these chromosomal regions suggests that haploinsufficiency for FOXC1 and GMDS genes accounts for the cardiac and neurodevelopmental phenotypes in the proband. The ring Chromosome 6 reported here is atypical as it involves a unique duplication of the distal long arm. Furthermore, the presence of renovascular disease is also a unique feature identified in this patient. To the best of our knowledge, a comparable ring Chromosome 6 involving both a distal deletion and duplication on different arms has not been previously reported. The renovascular disease identified in this patient may be a direct consequence of the described Chromosome rearrangement or a late clinical presentation in r(6) cases. This clinical finding may further support the implicated role of FOXC1 gene in renal pathology.

Harvey L Ozer - One of the best experts on this subject based on the ideXlab platform.

  • senescence of immortal human fibroblasts by the introduction of normal human Chromosome 6
    Proceedings of the National Academy of Sciences of the United States of America, 1994
    Co-Authors: Arbansjit K Sandhu, Karen Hubbard, Gursurinder P Kaur, Krishna K Jha, Harvey L Ozer, Raghbir S Athwal
    Abstract:

    Abstract In these studies we show that introduction of a normal human Chromosome 6 or 6q can suppress the immortal phenotype of simian virus 40-transformed human fibroblasts (SV/HF). Normal human fibroblasts have a limited life span in culture. Immortal clones of SV/HF displayed nonrandom rearrangements in Chromosome 6. Single human Chromosomes present in mouse/human monochromosomal hybrids were introduced into SV/HF via microcell fusion and maintained by selection for a dominant selectable marker gpt, previously integrated into the human Chromosome. Clones of SV/HF cells bearing Chromosome 6 displayed limited potential for cell division and morphological characteristics of senescent cells. The loss of Chromosome 6 from the suppressed clones correlated with the reappearance of immortal clones. Introduced Chromosome 6 in the senescing cells was distinguished from those of parental cells by the analysis for DNA sequences specific for the donor Chromosome. Our results further show that suppression of immortal phenotype in SV/HF is specific to Chromosome 6. Introduction of individual human Chromosomes 2, 8, or 19 did not impart cellular senescence in SV/HF. In addition, introduction of Chromosome 6 into human glioblastoma cells did not lead to senescence. Based upon these results we propose that at least one of the genes (SEN6) for cellular senescence in human fibroblasts is present on the long arm of Chromosome 6.

  • altered Chromosome 6 in immortal human fibroblasts
    Molecular and Cellular Biology, 1992
    Co-Authors: K Hubbardsmith, Krishna K Jha, P Patsalis, Jose R Pardinas, A S Henderson, Harvey L Ozer
    Abstract:

    Human diploid fibroblasts have a limited life span in vitro, and spontaneous immortalization is an extremely rare event. We have used transformation of human diploid fibroblasts by an origin-defective simian virus 40 genome to develop series of genetically matched immortal cell lines to analyze immortalization. Comparison of a preimmortal transformant (SVtsA/HF-A) with its uncloned and cloned immortalized derivatives (AR5 and HAL) has failed to reveal any major alteration involving the simian virus 40 genome. Karyotypic analysis, however, demonstrated that all of the immortal cell lines in this series have alterations of Chromosome 6 involving loss of the portion distal to 6q21. The karyotypic analysis was corroborated by DNA analyses. Southern analysis demonstrated that only one copy of three proto-oncogene loci (ros1, c-myb, and mas1) on 6q was retained in immortal cells. Polymerase chain reaction analysis of the microsatellite polymorphism at 6q22 (D6S87) showed loss of heterozygosity. In addition, elevated expression of c-myb (6q22-23) was observed. We hypothesize that the region at and/or distal to 6q21 plays a role in immortalization, consistent with the presence of a growth suppressor gene. 66 refs., 6 figs., 2 tabs.

G Soltesz - One of the best experts on this subject based on the ideXlab platform.

  • transient but not permanent neonatal diabetes mellitus is associated with paternal uniparental isodisomy of Chromosome 6
    Pediatrics, 2000
    Co-Authors: Robert Hermann, Anttipekka Laine, Calle Johansson, Tamas Niederland, Lidia Tokarska, Hanna Dziatkowiak, Jorma Ilonen, G Soltesz
    Abstract:

    Objectives. The factors determining the pathogenesis of transient and permanent neonatal diabetes mellitus are poorly characterized. The purpose of this study was to examine the role of Chromosome 6 in the pathogenesis of neonatal diabetes mellitus and to detect differences between these 2 phenotypes. Methods. Microsatellite markers (D6S334, D6S286, D6S310, D6S308, D6S292, D6S311, and D6S403) and human leukocyte antigen DQ alleles were examined using polymerase chain reaction and DNA fragment electrophoresis in 3 patients with transient and 3 patients with permanent neonatal diabetes mellitus. Humoral markers of islet cell autoimmunity and clinical characteristics were analyzed in the 2 groups. Results. A patient with transient neonatal diabetes mellitus (TND) and macroglossia carrying paternal uniparental isodisomy (UPD) of Chromosome 6 has been identified. The isodisomy affected the whole Chromosome; no maternal Chromosome 6 sequences were detected. The permanent neonatal diabetes mellitus cases and the other 2 cases with TND did not have UPD. None of the patients had high-risk type 1 diabetes human leukocyte antigen DQ alleles and most infants were negative for islet cell-specific autoantibodies indicating that none of the 2 forms of neonatal diabetes mellitus is likely to be of autoimmune origin. An association of TND and persistent granulocytopenia is described for the first time. Conclusions. We propose that transient and permanent forms of neonatal diabetes mellitus have different genetic background and represent different disease entities. TND is associated with UPD of Chromosome 6 suggesting that an imprinted gene on Chromosome 6 is responsible for this phenotype. It seems that 2 copies of the paternal allele are necessary for the development of TND; therefore, it is likely that overexpression of a putative gene located on Chromosome 6 alters pancreatic β-cell maturation and insulin secretion.