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Abstract
Colorectal cancer (CRC) arises as a consequence of the accumulation of genetic and epigenetic alterations in colonic epithelial cells during neoplastic transformation. Epigenetic modifications, particularly DNA methylation in selected gene promoters, are recognized as common molecular alterations in human tumors. Substantial efforts have been made to determine the cause and role of aberrant DNA methylation ("epigenomic instability") in colon carcinogenesis. In the colon, aberrant DNA methylation arises in tumor-adjacent, normal-appearing mucosa. Aberrant methylation also contributes to later stages of colon carcinogenesis through simultaneous methylation in key specific genes that alter specific oncogenic pathways. Hypermethylation of several gene clusters has been termed CpG island methylator phenotype and appears to define a subgroup of colon cancer distinctly characterized by pathological, clinical, and molecular features. DNA methylation of multiple promoters may serve as a biomarker for early detection in stool and blood DNA and as a tool for monitoring patients with CRC. DNA methylation patterns may also be predictors of metastatic or aggressive CRC. Therefore, the aim of this review is to understand DNA methylation as a driving force in colorectal neoplasia and its emerging value as a molecular marker in the clinic.
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Affiliation(s)
- Myoung Sook Kim
- Department of Otolaryngology, Head and Neck Surgery, The Johns Hopkins University School of Medicine, 1550 Orleans Street, CRB II-5M, Baltimore, MD, 21231, USA
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102
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Dyachenko OV, Shevchuk TV, Buryanov YI. Structural and functional features of the 5-methylcytosine distribution in the eukaryotic genome. Mol Biol 2010. [DOI: 10.1134/s0026893310020019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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103
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Looijenga LHJ, Hersmus R, de Leeuw BHCGM, Stoop H, Cools M, Oosterhuis JW, Drop SLS, Wolffenbuttel KP. Gonadal tumours and DSD. Best Pract Res Clin Endocrinol Metab 2010; 24:291-310. [PMID: 20541153 DOI: 10.1016/j.beem.2009.10.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Disorders of sex development (DSD), previously referred to as intersex, has been recognised as one of the main risk factors for development of type II germ cell tumours (GCTs), that is, seminomas/dysgerminomas and non-seminomas (e.g., embryonal carcinoma, yolk sac tumour, choriocarcinoma and teratoma). Within the testis, this type of cancer is the most frequent malignancy in adolescent and young adult Caucasian males. Although these males are not known to have dysgenetic gonads, the similarities in the resulting tumours suggest a common aetiological mechanism(s),--genetically, environmentally or a combination of both. Within the group of DSD patients, being in fact congenital conditions, the risk of malignant transformation of germ cells is highly heterogeneous, depending on a number of parameters, some of which have only recently been identified. Understanding of these recent insights will stimulate further research, with the final aim to develop an informative clinical decision tree for DSD patients, which includes optimal (early) diagnosis without overtreatment, such as prophylactic gonadectomy in the case of a low tumour risk.
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Affiliation(s)
- Leendert H J Looijenga
- Department of Pathology, Erasmus MC-University Medical Center Rotterdam, Josephine Nefkens Institute, Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
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104
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Skinner MK, Manikkam M, Guerrero-Bosagna C. Epigenetic transgenerational actions of environmental factors in disease etiology. Trends Endocrinol Metab 2010; 21:214-22. [PMID: 20074974 PMCID: PMC2848884 DOI: 10.1016/j.tem.2009.12.007] [Citation(s) in RCA: 464] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 12/09/2009] [Accepted: 12/14/2009] [Indexed: 12/26/2022]
Abstract
The ability of environmental factors to promote a phenotype or disease state not only in the individual exposed but also in subsequent progeny for successive generations is termed transgenerational inheritance. The majority of environmental factors such as nutrition or toxicants such as endocrine disruptors do not promote genetic mutations or alterations in DNA sequence. However, these factors do have the capacity to alter the epigenome. Epimutations in the germline that become permanently programmed can allow transmission of epigenetic transgenerational phenotypes. This review provides an overview of the epigenetics and biology of how environmental factors can promote transgenerational phenotypes and disease.
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Affiliation(s)
- Michael K Skinner
- Center for Reproductive Biology, School of Molecular Biosciences, Washington State University, Pullman, WA 99164-4236, USA.
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105
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Talbot NC, Powell AM, Caperna TJ, Garrett WM. Proteomic analysis of the major cellular proteins of bovine trophectoderm cell lines derived from IVP, parthenogenetic and nuclear transfer embryos: Reduced expression of annexins I and II in nuclear transfer-derived cell lines. Anim Reprod Sci 2010; 120:187-202. [PMID: 20400246 DOI: 10.1016/j.anireprosci.2010.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 03/11/2010] [Accepted: 03/23/2010] [Indexed: 10/19/2022]
Abstract
Trophectoderm cell lines were established from 8-day in vitro-cultured embryos of cattle derived from fertilization (IVF), somatic cell nuclear transfer (NT), or parthenogenetic activation (P) of in vitro-matured oocytes and from five 8-day-old in vivo (V) embryos. The most abundant cellular proteins of 5 V-, 16 NT-, 12 P-, and 16 IVF-derived cell lines were compared by 2D-gel electrophoresis and mass spectrometry; that is, the unaltered thiourea/urea extract of each cell culture was analyzed. Common protein spots (n=118) were examined, and 95% were identified with significant scores from protein and gene database searches. Of the proteins detected and identified, actin and cytokeratin-8 were found to be the most abundant. Other prominent cellular proteins were metabolic enzymes such as aldose reductase, phosphoglycerate mutase, enolase, triosephosphate isomerase, cytoskeletal interacting proteins transgelin and stratifin, anti-oxidant proteins peroxiredoxin 1 and anti-oxidant protein 2, and the calcium-dependent lipid-binding proteins annexins I and II. In comparative analysis of the 2D-gels, the NT-derived trophectoderm had less annexins I and II in comparison to the IVF- and P-derived trophectoderm. Because annexins I and II are abundant in the placenta and have functions important to the maintenance of placentation, the down-regulation of the annexin genes in the cultured NT trophectoderm may be related to the frequent failures of NT pregnancies.
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Affiliation(s)
- Neil C Talbot
- U.S. Department of Agriculture, Agricultural Research Service USDA, ARS, Animal and Natural Resources Institute, Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Beltsville, MD 20705-2350, United States.
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106
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Tat PA, Sumer H, Jones KL, Upton K, Verma PJ. The efficient generation of induced pluripotent stem (iPS) cells from adult mouse adipose tissue-derived and neural stem cells. Cell Transplant 2010; 19:525-36. [PMID: 20144262 DOI: 10.3727/096368910x491374] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Ectopic expression of key reprogramming transgenes in somatic cells enables them to adopt the characteristics of pluripotency. Such cells have been termed induced pluripotent stem (iPS) cells and have revolutionized the field of somatic cell reprogramming, as the need for embryonic material is obviated. One of the issues facing both the clinical translation of iPS cell technology and the efficient derivation of iPS cell lines in the research laboratory is choosing the most appropriate somatic cell type for induction. In this study, we demonstrate the direct reprogramming of a defined population of neural stem cells (NSCs) derived from the subventricular zone (SVZ) and adipose tissue-derived cells (ADCs) from adult mice using retroviral transduction of the Yamanaka factors Oct4, Sox2, Klf4, and c-Myc, and compared the results obtained with a mouse embryonic fibroblast (mEF) control. We isolated mEFs, NSCs, and ADCs from transgenic mice, which possess a GFP transgene under control of the Oct4 promoter, and validated GFP expression as an indicator of reprogramming. While transduction efficiencies were not significantly different among the different cell types (mEFs 68.70 +/- 2.62%, ADCs 70.61 +/- 15.4%, NSCs, 68.72 +/- 3%, p = 0.97), the number of GFP-positive colonies and hence the number of reprogramming events was significantly higher for both NSCs (13.50 +/- 4.10 colonies, 0.13 +/- 0.06%) and ADCs (118.20 +/- 38.28 colonies, 1.14 +/- 0.77%) when compared with the mEF control (3.17 +/- 0.29 colonies, 0.03 +/- 0.005%). ADCs were most amenable to reprogramming with an 8- and 38-fold greater reprogramming efficiency than NSCs and mEFs, respectively. Both NSC iPS and ADC iPS cells were demonstrated to express markers of pluripotency and could differentiate to the three germ layers, both in vitro and in vivo, to cells representative of the three germ lineages. Our findings confirm that ADCs are an ideal candidate as a readily accessible somatic cell type for high efficiency establishment of iPS cell lines.
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Affiliation(s)
- Pollyanna A Tat
- Centre for Reproduction and Development, Monash Institute of Medical Research, Melbourne, Victoria, Australia
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107
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Imsoonthornruksa S, Lorthongpanich C, Sangmalee A, Srirattana K, Laowtammathron C, Tunwattana W, Somsa W, Ketudat-Cairns M, Parnpai R. Abnormalities in the transcription of reprogramming genes related to global epigenetic events of cloned endangered felid embryos. Reprod Fertil Dev 2010; 22:613-24. [DOI: 10.1071/rd09108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Accepted: 10/03/2009] [Indexed: 11/23/2022] Open
Abstract
The present study examined transcription levels of the Oct4, DNMT1, DNMT3a, DNMT3b, HAT1 and HDAC1 genes in cloned felid embryos developing from single one-cell to blastocyst stages. IVF, cloned domestic and leopard cat embryos had low Oct4 and HAT1 levels during the early stages, but transcript expression increased at the eight-cell and blastocyst stages. In contrast, expression in the cloned marble cat embryos was low at all stages. Transcription patterns of HDAC1 were altered in cloned embryos compared with IVF embryos. Transcription levels of DNMT1 decreased markedly throughout development of both IVF and cloned embryos. In IVF embryos, DNMT3a transcripts rarely appeared in the four- to eight-cell stages, but levels increased in the morula to blastocyst stages. In contrast, in cloned embryos, DNMT3a transcript levels were high at the one- to two-cell stages, decreased during subsequent cell division and then increased again at the blastocyst stage. The IVF and cloned embryos showed similar DNMT3b transcription patterns, starting with low levels at the two-cell to morula stages and reaching a maximum at the blastocyst stage. These results suggest that the low level of Oct4 transcripts may be responsible, in part, for the failure of blastocyst production in the cloned marbled cat. However, higher transcription of the DNA methylation genes and lower transcription of the histone acetylation genes were observed in cloned compared with IVF embryos, suggesting that the felids’ donor nucleus could not completely reprogramme the nuclear genome and so the re-establishment of embryonic totipotency was not achieved.
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108
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Brevini TAL, Pennarossa G, Antonini S, Paffoni A, Tettamanti G, Montemurro T, Radaelli E, Lazzari L, Rebulla P, Scanziani E, de Eguileor M, Benvenisty N, Ragni G, Gandolfi F. Cell lines derived from human parthenogenetic embryos can display aberrant centriole distribution and altered expression levels of mitotic spindle check-point transcripts. Stem Cell Rev Rep 2009; 5:340-52. [PMID: 20058199 DOI: 10.1007/s12015-009-9086-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Accepted: 08/04/2009] [Indexed: 10/20/2022]
Abstract
Human parthenogenetic embryos have recently been proposed as an alternative, less controversial source of embryonic stem cell (ESC) lines; however many aspects related to the biology of parthenogenetic embryos and parthenogenetic derived cell lines still need to be elucidated. We present here results on human cell lines (HP1 and HP3) derived from blastocysts obtained by oocyte parthenogenetic activation. Cell lines showed typical ESC morphology, expressed Oct-4, Nanog, Sox-2, Rex-1, alkaline phosphatase, SSEA-4, TRA 1-81 and had high telomerase activity. Expression of genes specific for different embryonic germ layers was detected from HP cells differentiated upon embryoid body (EBs) formation. Furthermore, when cultured in appropriate conditions, HP cell lines were able to differentiate into mature cell types of the neural and hematopoietic lineages. However, the injection of undifferentiated HP cells in immunodeficient mice resulted either in poor differentiation or in tumour formation with the morphological characteristics of myofibrosarcomas. Further analysis of HP cells indicated aberrant levels of molecules related to spindle formation as well as the presence of an abnormal number of centrioles and autophagic activity. Our results confirm and extend the notion that human parthenogenetic stem cells can be derived and can differentiate in mature cell types, but also highlight the possibility that, alteration of the proliferation mechanisms may occur in these cells, suggesting great caution if a therapeutic use of this kind of stem cells is considered.
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Affiliation(s)
- Tiziana A L Brevini
- Laboratory of Biomedical Embryology, Centre for Stem Cell Research, University of Milan, 20133 Milan, Italy.
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109
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Vargas AO. Did Paul Kammerer discover epigenetic inheritance? A modern look at the controversial midwife toad experiments. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2009; 312:667-78. [DOI: 10.1002/jez.b.21319] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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110
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Ahluwalia JK, Hariharan M, Bargaje R, Pillai B, Brahmachari V. Incomplete penetrance and variable expressivity: is there a microRNA connection? Bioessays 2009; 31:981-92. [PMID: 19642110 DOI: 10.1002/bies.200900066] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Incomplete penetrance and variable expressivity are non-Mendelian phenomena resulting in the lack of correlation between genotype and phenotype. Not withstanding the diversity in mechanisms, differential expression of homologous alleles within cells manifests as variations in penetrance and expressivity of mutations between individuals of the same genotype. These phenomena are seen most often in dominantly inherited diseases, implying that they are sensitive to concentration of the gene product. In this framework and the advances in understanding the role of microRNA (miRNA) in fine-tuning gene expression at translational level, we propose miRNA-mediated regulation as a mechanism for incomplete penetrance and variable expressivity. The presence of miRNA binding sites at 3' UTR, co-expression of target gene-miRNA pairs for genes showing incomplete penetrance and variable expressivity derived from available data lend support to our hypothesis. Single nucleotide polymorphisms in the miRNA target site facilitate the implied differential targeting of the transcripts from homologous alleles.
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Affiliation(s)
- Jasmine K Ahluwalia
- Dr. B. R. Ambedkar Centre for Biomedical Research, Delhi University, Delhi, India
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111
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Jahnke S, Scholten S. Epigenetic Resetting of a Gene Imprinted in Plant Embryos. Curr Biol 2009; 19:1677-81. [DOI: 10.1016/j.cub.2009.08.053] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 08/11/2009] [Accepted: 08/12/2009] [Indexed: 11/26/2022]
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112
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Skinner MK, Guerrero-Bosagna C. Environmental signals and transgenerational epigenetics. Epigenomics 2009; 1:111-117. [PMID: 20563319 DOI: 10.2217/epi.09.11] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The ability of an environmental factor or toxicant to promote a phenotype or disease state not only in the individual exposed, but also in subsequent progeny for multiple generations, is termed transgenerational inheritance. The majority of environmental agents do not promote genetic mutations or alterations in DNA sequence, but do have the capacity to alter the epigenome. Although most environmental exposures will influence somatic cells and not allow the transgenerational transmission of a phenotype, the ability of an environmental factor to reprogram the germline epigenome can promote a transgenerational inheritance of phenotypes and disease states. A limited number of critical developmental periods exist when environmental signals can produce a significant epigenetic reprogramming of the germline. In this review, the ability of environmental factors or toxicants to promote epigenetic transgenerational phenotypes is reviewed.
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113
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Erilova A, Brownfield L, Exner V, Rosa M, Twell D, Scheid OM, Hennig L, Köhler C. Imprinting of the polycomb group gene MEDEA serves as a ploidy sensor in Arabidopsis. PLoS Genet 2009; 5:e1000663. [PMID: 19779546 PMCID: PMC2738949 DOI: 10.1371/journal.pgen.1000663] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Accepted: 08/26/2009] [Indexed: 11/18/2022] Open
Abstract
Balanced maternal and paternal genome contributions are a requirement for successful seed development. Unbalanced contributions often cause seed abortion, a phenomenon that has been termed "triploid block." Misregulation of imprinted regulatory genes has been proposed to be the underlying cause for abnormalities in growth and structure of the endosperm in seeds with deviating parental contributions. We identified a mutant forming unreduced pollen that enabled us to investigate direct effects of unbalanced parental genome contributions on seed development and to reveal the underlying molecular mechanism of dosage sensitivity. We provide evidence that parent-of-origin-specific expression of the Polycomb group (PcG) gene MEDEA is causally responsible for seed developmental aberrations in Arabidopsis seeds with increased paternal genome contributions. We propose that imprinted expression of PcG genes is an evolutionary conserved mechanism to balance parental genome contributions in embryo nourishing tissues.
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Affiliation(s)
- Aleksandra Erilova
- Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Lynette Brownfield
- Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, Zurich, Switzerland
- Department of Biology, University of Leicester, Leicester, United Kingdom
| | - Vivien Exner
- Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Marisa Rosa
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria
| | - David Twell
- Department of Biology, University of Leicester, Leicester, United Kingdom
| | - Ortrun Mittelsten Scheid
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria
| | - Lars Hennig
- Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Claudia Köhler
- Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, Zurich, Switzerland
- * E-mail:
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114
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Guerrero-Bosagna CM, Skinner MK. Epigenetic transgenerational effects of endocrine disruptors on male reproduction. Semin Reprod Med 2009; 27:403-8. [PMID: 19711250 DOI: 10.1055/s-0029-1237428] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Endocrine-disrupting chemicals generally function as steroid receptor signaling antagonists or agonists that influence development to promote adult-onset disease. Exposure to the endocrine disruptors during the initiation of male reproductive tract development interferes with the normal hormonal signaling and formation of male reproductive organs. In particular, exposure to the endocrine disruptor vinclozolin promotes transgenerational transmission of adult-onset disease states such as male infertility, increased frequencies of tumors, prostate disease, kidney diseases, and immune abnormalities that develop as males age. An epigenetic change in the germ line would be involved in the transgenerational transmission of these induced phenotypes. Nevertheless, other studies have also reported transgenerational transmission of induced epigenetic changes, without altering the germ line. Here we propose a nomenclature to help clarify both cases of transgenerational epigenetic transmission. An intrinsic epigenetic transgenerational process would require a germ-line involvement, a permanent alteration in the germ cell epigenome, and only one exposure to the environmental factor. An extrinsic epigenetic transgenerational process would involve an epigenetic alteration in a somatic tissue and require exposure at each generation to maintain the transgenerational phenotype.
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Affiliation(s)
- Carlos M Guerrero-Bosagna
- Center for Reproductive Biology, School of Molecular Biosciences, Washington State University, Pullman, Washington 99164-4231, USA
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115
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Saitou M. Germ cell specification in mice. Curr Opin Genet Dev 2009; 19:386-95. [DOI: 10.1016/j.gde.2009.06.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2009] [Revised: 05/29/2009] [Accepted: 06/05/2009] [Indexed: 01/16/2023]
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116
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Lauc G, Zoldos V. Epigenetic regulation of glycosylation could be a mechanism used by complex organisms to compete with microbes on an evolutionary scale. Med Hypotheses 2009; 73:510-2. [PMID: 19560282 DOI: 10.1016/j.mehy.2009.03.059] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2009] [Revised: 05/29/2009] [Accepted: 03/31/2009] [Indexed: 11/19/2022]
Abstract
Glycosylation is the most diverse post-translational protein modification. It is essential for multicellular life and its complete absence is embryonically lethal. Hundreds of specific enzymes are involved in the synthesis of complex oligosaccharide structures that are covalently bound to protein backbones. This process is not template driven and thus results in a huge complexity of glycoproteome, estimated to be several orders of magnitude larger than proteome. Large structural variability provided by glycans represents a significant evolutionary advantage and nearly all proteins invented after the appearance of the multicellular life are glycosylated. Glycosylation represents a way how complex organisms could develop novel structural features without introducing probably deleterious changes in their genome. Intricate mechanisms by which the interplay of gene expression and intracellular localization of their products give rise to specific glycan structures is only starting to be understood, but some evidence suggests that epigenetic regulation of glycosylation might be used to create novel biological structures. Here we suggest a hypothesis that epigenetic regulation of genes involved in glycan synthesis might represent a way how newly developed structural advantages could be transmitted through generations, thus providing a tool for complex organisms to compete with high speed of evolution of unicellular organisms.
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Affiliation(s)
- Gordan Lauc
- University of Osijek School of Medicine, J. Huttlera 4, HR-31000 Osijek, Croatia.
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117
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Looijenga LHJ. Human testicular (non)seminomatous germ cell tumours: the clinical implications of recent pathobiological insights. J Pathol 2009; 218:146-62. [PMID: 19253916 DOI: 10.1002/path.2522] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Human germ cell tumours (GCTs) comprise several types of neoplasias with different pathogeneses and clinical behaviours. A classification into five subtypes has been proposed. Here, the so-called type II testicular GCTs (TGCTs), ie the seminomas and non-seminomas, will be reviewed with emphasis on pathogenesis and clinical implications. Various risk factors have been identified that define subpopulations of men who are amenable to early diagnosis. TGCTs are omnipotent, able to generate all differentiation lineages, both embryonic and extra-embryonic, as well as the germ cell lineage itself. The precursor lesion, composed of primordial germ cells/gonocytes, is referred to as carcinoma in situ of the testis (CIS) and gonadoblastoma of the dysgenetic gonad. These pre-malignant cells retain embryonic characteristics, which probably explains the unique responsiveness of the derived tumours to DNA-damaging agents. Development of CIS and gonadoblastoma is crucially dependent on the micro-environment created by Sertoli cells in the testis, and granulosa cells in the dysgenetic gonad. OCT3/4 has high sensitivity and specificity for CIS/gonadoblastoma, seminoma, and embryonal carcinoma, and is useful for the detection of CIS cells in semen, thus a promising tool for non-invasive screening. Overdiagnosis of CIS due to germ cell maturation delay can be avoided using immunohistochemical detection of stem cell factor (SCF). Immunohistochemistry is helpful in making the distinction between seminoma and embryonal carcinoma, especially SOX17 and SOX2. The different non-seminomatous histological elements can be recognized using various markers, such as AFP and hCG, while others need confirmation. The value of micro-satellite instability as well as BRAF mutations in predicting treatment resistance needs validation in prospective trials. The availability of representative cell lines, both for seminoma and for embryonal carcinoma, allows mechanistic studies into the initiation and progression of this disease.
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Affiliation(s)
- Leendert H J Looijenga
- Department of Pathology, Erasmus MC-Erasmus University Medical Center, Daniel den Hoed Cancer Center, Josephine Nefkens Institute, Rotterdam, The Netherlands.
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118
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Furukawa S, Haruta M, Arai Y, Honda S, Ohshima J, Sugawara W, Kageyama Y, Higashi Y, Nishida K, Tsunematsu Y, Nakadate H, Ishii M, Kaneko Y. Yolk sac tumor but not seminoma or teratoma is associated with abnormal epigenetic reprogramming pathway and shows frequent hypermethylation of various tumor suppressor genes. Cancer Sci 2009; 100:698-708. [PMID: 19245437 PMCID: PMC11159010 DOI: 10.1111/j.1349-7006.2009.01102.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 12/25/2008] [Accepted: 12/28/2008] [Indexed: 01/13/2023] Open
Abstract
Germ cell tumors (GCTs) are thought to arise from primordial germ cells (PGCs) that undergo epigenetic reprogramming: erasure of the somatic imprint in the genital ridge, and re-establishment of the sex-specific imprint at gametogenesis in the developing gonad. Previous studies suggested that GCTs show epigenetic patterns reflecting the reprogramming process of PGCs; however, epigenetic alterations of imprinted genes and their relationship with the methylation status of tumor suppressor genes (TSGs) have not been comprehensively studied. We analyzed the methylation status of the H19 and SNRPN differential methylated regions (DMRs) and the promoter region of 17 TSGs, and the expression status of H19, IGF2 and SNRPN in 45 GCTs, and found that 25 and 20 were in the normal and abnormal reprogramming pathways, respectively, defined on the basis of the methylation status of the two DMRs and the anatomical tumor site. The methylation pattern of the H19 and SNRPN DMRs was total erasure in seminomas, mostly physiological in teratomas, and various in yolk sac tumors. There were no correlations between the methylation status of the H19 DMR and mono- or biallelic expression of H19 or IGF2. Furthermore, we found that yolk sac tumors had a higher number of methylated TSGs than seminomas (P < 0.001) teratomas (P = 0.004) or other childhood tumors. While TSG methylation was known to have prognostic implications in various cancers, it did not affect the outcomes of patients with yolk sac tumor, suggesting that mechanisms of TSG methylation may be different between yolk sac tumor and other cancers.
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Affiliation(s)
- Shinsuke Furukawa
- Department of Cancer Diagnosis, Research Institute for Clinical Oncology, Saitama Cancer Center, 818 Komuro, Ina, Saitama 362-0806, Japan
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119
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Lin H, Yin H. A novel epigenetic mechanism in Drosophila somatic cells mediated by Piwi and piRNAs. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2009; 73:273-81. [PMID: 19270080 DOI: 10.1101/sqb.2008.73.056] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Small noncoding RNAs have emerged as key players in epigenetic regulation. Recently, a novel class of small RNAs that interact with Piwi proteins has been discovered in the mammalian and Drosophila germ line. These Piwi-interacting RNAs (piRNAs) represent a distinct small RNA pathway that is widely thought to function only in the germ line. In this chapter, we review our recent work with our collaborators on the epigenetic function of the Drosophila Piwi protein and its associated piRNAs in somatic cells. This work has revealed a novel epigenetic mechanism mediated by Piwi and its associated piRNAs in somatic cells that might also be applicable to the germ line. On the basis of these results, we propose a "Piwi-piRNA guidance hypothesis" for Piwi/piRNA-mediated epigenetic programming, in which the Piwi-piRNA complex serves as sequence-recognition machinery that recruits epigenetic effectors such as heterochromatin protein 1a (HP1a) to specific sites in the genome to execute epigenetic regulation.
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Affiliation(s)
- H Lin
- Yale Stem Cell Center and Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06509, USA
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120
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Edwards TM, Myers JP. Environmental exposures and gene regulation in disease etiology. CIENCIA & SAUDE COLETIVA 2009; 13:269-81. [PMID: 18813540 DOI: 10.1590/s1413-81232008000100030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Accepted: 05/21/2007] [Indexed: 12/21/2022] Open
Abstract
Health or disease is shaped for all individuals by interactions between their genes and environment. Exactly how the environment changes gene expression and how this can lead to disease are being explored in a fruitful new approach to environmental health research, representative studies of which are reviewed here. We searched Web of Science and references of relevant publications to understand the diversity of gene regulatory mechanisms affected by environmental exposures with disease implications. Pharmaceuticals, pesticides, air pollutants, industrial chemicals, heavy metals, hormones, nutrition, and behavior can change gene expression through a broad array of gene regulatory mechanisms. Furthermore, chemically induced changes in gene regulation are associated with serious and complex human diseases, including cancer, diabetes and obesity, infertility, respiratory diseases, allergies, and neurodegenerative disorders such as Parkinson and Alzheimer diseases. The reviewed studies indicate that genetic predisposition for disease is best predicted in the context of environmental exposures. And the genetic mechanisms investigated in these studies offer new avenues for risk assessment research. Finally, we are likely to witness dramatic improvements in human health, and reductions in medical costs, if environmental pollution is decreased.
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Affiliation(s)
- Thea M Edwards
- Department of Zoology, University of Florida, Gainesville, FL 32611, USA.
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121
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Final checkup of neoplastic DNA replication: Evidence for failure in decision-making at the mitotic cell cycle checkpoint G1/S. Exp Hematol 2008; 36:1403-16. [DOI: 10.1016/j.exphem.2008.07.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 07/29/2008] [Accepted: 07/29/2008] [Indexed: 11/24/2022]
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122
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Paffoni A, Brevini T, Gandolfi F, Ragni G. Parthenogenetic Activation: Biology and Applications in the ART Laboratory. Placenta 2008; 29 Suppl B:121-5. [DOI: 10.1016/j.placenta.2008.08.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Revised: 08/07/2008] [Accepted: 08/07/2008] [Indexed: 10/21/2022]
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123
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Tachibana M, Matsumura Y, Fukuda M, Kimura H, Shinkai Y. G9a/GLP complexes independently mediate H3K9 and DNA methylation to silence transcription. EMBO J 2008; 27:2681-90. [PMID: 18818694 DOI: 10.1038/emboj.2008.192] [Citation(s) in RCA: 286] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2008] [Accepted: 08/27/2008] [Indexed: 01/15/2023] Open
Abstract
Methylation of DNA and lysine 9 of histone H3 (H3K9) are well-conserved epigenetic marks for transcriptional silencing. Although H3K9 methylation directs DNA methylation in filamentous fungi and plants, this pathway has not been corroborated in mammals. G9a and GLP/Eu-HMTase1 are two-related mammalian lysine methyltransferases and a G9a/GLP heteromeric complex regulates H3K9 methylation of euchromatin. To elucidate the function of G9a/GLP-mediated H3K9 methylation in the regulation of DNA methylation and transcriptional silencing, we characterized ES cells expressing catalytically inactive mutants of G9a and/or GLP. Interestingly, in ES cells expressing a G9a-mutant/GLP complex that does not rescue global H3K9 methylation, G9a/GLP-target genes remain silent. The CpG sites of the promoter regions of these genes were hypermethylated in such mutant ES cells, but hypomethylated in G9a- or GLP-KO ES cells. Treatment with a DNA methyltransferase inhibitor reactivates these G9a/GLP-target genes in ES cells expressing catalytically inactive G9a/GLP proteins, but not the wild-type proteins. This is the first clear evidence that G9a/GLP suppresses transcription by independently inducing both H3K9 and DNA methylation.
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Affiliation(s)
- Makoto Tachibana
- Experimental Research Center for Infectious Diseases, Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto, Japan.
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124
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125
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Hersmus R, de Leeuw BHCGM, Wolffenbuttel KP, Drop SLS, Oosterhuis JW, Cools M, Looijenga LHJ. New insights into type II germ cell tumor pathogenesis based on studies of patients with various forms of disorders of sex development (DSD). Mol Cell Endocrinol 2008; 291:1-10. [PMID: 18403106 DOI: 10.1016/j.mce.2008.02.028] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 02/26/2008] [Indexed: 11/18/2022]
Abstract
Disorders of sex development (DSD), previously known as intersex, refer to congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Patients with specific variants of this disorder have an elevated risk for the development of so-called type II germ cell cancers, i.e., the seminomatous and nonseminatous tumors, referred to as germ cell tumors (GCTs). Specifically DSD patients with gonadal dysgenesis or hypovirilization are at risk. A prerequisite for type II GCT formation is the presence of a specific part of the Y chromosome (referred to as the GBY region), with the TSPY gene being the most likely candidate. Also the octamer binding transcription factor OCT3/4 is consistently expressed in all type II GCTs with pluripotent potential, as well as in the precursor lesions carcinoma in situ (CIS) in case of a testis and gonadoblastoma (GB) in the DSD gonad. The actual risk for malignant transformation in individual DSD patients is hard to predict, because of confusing terminology referring to the different forms of DSD, and unclear criteria for identification of the presence of malignant germ cells, especially in young patients. This is specifically due to the phenomenon of delay of germ cell maturation, which might result in over diagnosis. This review will give novel insight into the pathogenesis of the type II GCTs through the study of patients with various forms of DSD for which the underlying molecular defect is known. To allow optimal understanding of the pathogenesis of this type of cancers, first normal gonadal development, especially regarding the germ cell lineage, will be discussed, after which type II GCTs will be introduced. Subsequently, the relationship between type II GCTs and DSD will be described, resulting in a number of new insights into the development of the precursor lesions of these tumors.
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Affiliation(s)
- Remko Hersmus
- Department of Pathology, Erasmus MC-University Medical Center Rotterdam, Daniel den Hoed Cancer Center, Josephine Nefkens Institute, Rotterdam, The Netherlands
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126
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Pereira CF, Terranova R, Ryan NK, Santos J, Morris KJ, Cui W, Merkenschlager M, Fisher AG. Heterokaryon-based reprogramming of human B lymphocytes for pluripotency requires Oct4 but not Sox2. PLoS Genet 2008; 4:e1000170. [PMID: 18773085 PMCID: PMC2527997 DOI: 10.1371/journal.pgen.1000170] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 07/15/2008] [Indexed: 12/14/2022] Open
Abstract
Differentiated cells can be reprogrammed through the formation of heterokaryons and hybrid cells when fused with embryonic stem (ES) cells. Here, we provide evidence that conversion of human B-lymphocytes towards a multipotent state is initiated much more rapidly than previously thought, occurring in transient heterokaryons before nuclear fusion and cell division. Interestingly, reprogramming of human lymphocytes by mouse ES cells elicits the expression of a human ES-specific gene profile, in which markers of human ES cells are expressed (hSSEA4, hFGF receptors and ligands), but markers that are specific to mouse ES cells are not (e.g., Bmp4 and LIF receptor). Using genetically engineered mouse ES cells, we demonstrate that successful reprogramming of human lymphocytes is independent of Sox2, a factor thought to be required for induced pluripotent stem (iPS) cells. In contrast, there is a distinct requirement for Oct4 in the establishment but not the maintenance of the reprogrammed state. Experimental heterokaryons, therefore, offer a powerful approach to trace the contribution of individual factors to the reprogramming of human somatic cells towards a multipotent state. One of the most pressing objectives of medical research today is the development of approaches to restore the function of tissues damaged by accident or disease. An important goal for this work is the isolation of stem cell populations to replace missing or nonfunctioning cells. Because problems of immune rejection are likely to occur unless the recipient and donor stem cells are very closely matched, a desirable strategy is to convert differentiated cells (such as white blood cells) from patients into immature tailored stem cell populations. Here, we have experimentally fused human white blood cells and mouse embryonic stem cells and shown that this reprograms them to become stem-like. This kind of “differentiation reversal” is shown to be rapid and stable. It requires the stem cell–specific factor Oct4, but does not require Sox2. This approach allows the identification of factors that are required to reprogram human blood cells with the long-term perspective to eventually generate patient-specific stem cells.
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Affiliation(s)
- Carlos F. Pereira
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
| | - Rémi Terranova
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
| | - Natalie K. Ryan
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
| | - Joana Santos
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
| | - Kelly J. Morris
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
| | - Wei Cui
- Stem Cell Initiative, Institute of Reproductive and Developmental Biology, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Matthias Merkenschlager
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
| | - Amanda G. Fisher
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom
- * E-mail:
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127
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Cantz T, Bleidissel M, Stehling M, Schöler HR. In vitro differentiation of reprogrammed murine somatic cells into hepatic precursor cells. Biol Chem 2008; 389:889-96. [PMID: 18627307 DOI: 10.1515/bc.2008.107] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recently, a new approach to reprogram somatic cells into pluripotent stem cells was shown by fusion of somatic cells with embryonic stem (ES) cells, which results in a tetraploid karyotype. Normal hepatocytes are often polyploid, so we decided to investigate the differentiation potential of fusion hybrids into hepatic cells. We chose toxic milk mice (a model of Wilson's disease) and performed initial transplantation experiments using this potential cell therapy approach. Mononuclear bone marrow cells from Rosa26 mice were fused with OG2 (Oct4-GFP transgenic) ES cells. Unfused ES cells were eliminated by selection with G418 for OG2-Rosa26 hybrids and fusion-derived colonies could be subcloned. Using an endodermal differentiation protocol, hepatic precursor cells could be generated. After FACS depletion of contaminating Oct4-GFP-positive cells, the hepatic precursor cells were transplanted into immunosuppressed toxic milk mice by intrasplenic injection. However, five out of eight mice showed teratoma formation within 3-6 weeks after transplantation in the spleen and liver. In conclusion, a hepatic precursor cell type was achieved from mononuclear bone marrow cell-ES cell hybrids and preliminary transplantation experiments confirmed engraftment, but also showed teratoma formation, which needs to be excluded by using more stringent purification strategies.
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Affiliation(s)
- Tobias Cantz
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstr. 20, Münster, Germany.
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128
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Hua J, Sidhu K. Recent advances in the derivation of germ cells from the embryonic stem cells. Stem Cells Dev 2008; 17:399-411. [PMID: 18576912 DOI: 10.1089/scd.2007.0225] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In recent years, considerable progress has been made in the establishment and differentiation of human embryonic stem (ES) cell lines. The primordial germ cells (PGCs) and embryonic germ (EG) cells derived from them share many of their properties with ES cells. ES cell lines have now been derived from different stages of germ cell development and they have differentiated into gametes and shown embryonic development in mice, including the production of live pups. Conversely, germ cells can also be derived from ES cells. It has been demonstrated that murine (m) ES cells can differentiate into PGCs and subsequently into early gametes (oocytes and sperms) and blastocysts. Recently, immature sperm cells derived from mES cells in culture have produced live offspring. Preliminary research has indicated that human (h) ES cells probably have the potential to differentiate into germ cells. Adult stem cells have been reported to differentiate into mature germ cells in vitro. Therefore, stem cells may offer a valuable in vitro model for the investigation of germ cell development and the early stages of human gametogenesis, including epigenetic modifications of the germ line. This review discusses recent developments in the derivation and specification of mammalian germ cells from ES cells and describes some of the mechanisms of germ cell development.
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Affiliation(s)
- Jinlian Hua
- Diabetes Transplant Unit, Prince of Wales Hospital and The University of New South Wales, Randwick, NSW, Australia
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129
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Penkov LI, Kondrachina MS, Mironova OV, Platonov ES. Expression of imprinted Igf2 and Peg1/Mest genes in postimplantation parthenogenetic mouse embryos treated with transforming growth factor α in vitro. RUSS J GENET+ 2008. [DOI: 10.1134/s1022795408080188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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130
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Parthenogenesis as an approach to pluripotency: advantages and limitations involved. ACTA ACUST UNITED AC 2008; 4:127-35. [PMID: 18548354 DOI: 10.1007/s12015-008-9027-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/05/2008] [Indexed: 10/22/2022]
Abstract
Embryonic stem cells (ESCs) are invaluable cells derived from the inner cell mass of the mammalian blastocyst. They have nearly indefinite self-renewal, retain their developmental potential after prolonged periods in culture and display great plasticity that allow them to differentiate into all cell types of the body. They provide exciting opportunities to develop unique models for developmental research and hold great potential for cell and tissue replacement therapy. However, these unique cells cannot be obtained without destroying an embryo and, despite the potential therapeutic usefulness, their derivation in the human raises substantial ethical as well as legal and political concerns because it unavoidably involves the destruction of viable embryos. In the recent years a number of scientific proposals that do not require the generation and subsequent destruction of human embryos have been put forward in an attempt to fill the gap between ethical questions and potential scientific and medical benefits. In this review we briefly summarize data obtained from the literature related to these different alternative approaches and focus in more details on our experience in the derivation of parthenothes, as a possible alternative source for pluripotent cells, discussing the advantages as well as the limits of these cell lines.
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131
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Keverne EB, Curley JP. Epigenetics, brain evolution and behaviour. Front Neuroendocrinol 2008; 29:398-412. [PMID: 18439660 DOI: 10.1016/j.yfrne.2008.03.001] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 11/30/2007] [Accepted: 03/01/2008] [Indexed: 12/14/2022]
Abstract
Molecular modifications to the structure of histone proteins and DNA (chromatin) play a significant role in regulating the transcription of genes without altering their nucleotide sequence. Certain epigenetic modifications to DNA are heritable in the form of genomic imprinting, whereby subsets of genes are silenced according to parent-of-origin. This form of gene regulation is primarily under matrilineal control and has evolved partly to co-ordinate in-utero development with maternal resource availability. Changes to epigenetic mechanisms in post-mitotic neurons may also be activated during development in response to environmental stimuli such as maternal care and social interactions. This results in long-lasting stable, or short-term dynamic, changes to the neuronal phenotype producing long-term behavioural consequences. Use of evolutionary conserved mechanisms have thus been adapted to modify the control of gene expression and embryonic growth of the brain as well as allowing for plastic changes in the post-natal brain in response to external environmental and social cues.
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Affiliation(s)
- Eric B Keverne
- Sub-Department of Animal Behaviour, University of Cambridge, Madingley, Cambridge, CB23 8AA, UK.
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132
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Yoon J, Lee KS, Park JS, Yu K, Paik SG, Kang YK. dSETDB1 and SU(VAR)3-9 sequentially function during germline-stem cell differentiation in Drosophila melanogaster. PLoS One 2008; 3:e2234. [PMID: 18493619 PMCID: PMC2377335 DOI: 10.1371/journal.pone.0002234] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 04/11/2008] [Indexed: 11/18/2022] Open
Abstract
Germline-stem cells (GSCs) produce gametes and are thus true “immortal stem cells”. In Drosophila ovaries, GSCs divide asymmetrically to produce daughter GSCs and cystoblasts, and the latter differentiate into germline cysts. Here we show that the histone-lysine methyltransferase dSETDB1, located in pericentric heterochromatin, catalyzes H3-K9 trimethylation in GSCs and their immediate descendants. As germline cysts differentiate into egg chambers, the dSETDB1 function is gradually taken over by another H3-K9-specific methyltransferase, SU(VAR)3–9. Loss-of-function mutations in dsetdb1 or Su(var)3–9 abolish both H3K9me3 and heterochromatin protein-1 (HP1) signals from the anterior germarium and the developing egg chambers, respectively, and cause localization of H3K9me3 away from DNA-dense regions in most posterior germarium cells. These results indicate that dSETDB1 and SU(VAR)3–9 act together with distinct roles during oogenesis, with dsetdb1 being of particular importance due to its GSC-specific function and more severe mutant phenotype.
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Affiliation(s)
- Jeongheon Yoon
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
- Department of Biology, Chungnam National University, Daejon, Korea
| | - Kyu-Sun Lee
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Jung Sun Park
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Kweon Yu
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Sang-Gi Paik
- Department of Biology, Chungnam National University, Daejon, Korea
| | - Yong-Kook Kang
- Center for Regenerative Medicine, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
- * E-mail:
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133
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Talbot NC, Powell AM, Ocón OM, Caperna TJ, Camp M, Garrett WM, Ealy AD. Comparison of the interferon-tau expression from primary trophectoderm outgrowths derived from IVP, NT, and parthenogenote bovine blastocysts. Mol Reprod Dev 2008; 75:299-308. [PMID: 17721989 DOI: 10.1002/mrd.20741] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The expression of interferon-tau (IFN-tau) is essential for bovine embryo survival in the uterus. An evaluation of IFN-tau production from somatic cell nuclear transfer (NT)-embryo-derived primary trophectoderm cultures in comparison to trophectoderm cultured from parthenogenote (P) and in vitro matured, fertilized, and cultured (IVP) bovine embryos was performed. In Experiment 1, the success/failure ratio for primary trophectoderm colony formation was similar for IVP and NT blastocysts [IVP = 155/29 (84%); NT 104/25 (81%)], but was decreased (P = .05) for P blastocysts [54/43 (56%)]. Most trophectoderm colonies reached diameters of at least 1 cm within 3-4 weeks, and at this time, 72 hr conditioned cell culture medium was measured for IFN-tau concentration by antiviral activity assay. The amount of IFN-tau produced by IVP-outgrowths [4311 IU/mL (n = 155)] was greater (P < .05) than that from NT- [626 IU/mL (n = 104)] and P - [1595 IU/mL (n = 54)] derived trophectoderm. Differential expression of IFN-tau was confirmed by immunoblotting. In Experiment 2, colony formation was again similar for IVP and NT blastocysts [IVP = 70/5 (93%); NT 67/1 (99%)] and less (P < .05) for P blastocysts [65/27 (70%)]. Analysis of trophectoderm colony size after 23 days in culture showed a similar relationship with P-derived colonies being significantly smaller in comparison to IVP and NT colonies. A differential expression of IFN-tau was also observed again, but this time as measured over time in culture. Maximal IFN-tau production was found at day-14 of primary culture and diminished to a minimum by the 23rd day.
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Affiliation(s)
- Neil C Talbot
- USDA, ARS, ANRI, Biotechnology and Germplasm Laboratory, Beltsville, Maryland 20705-2350, USA.
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134
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Wong CC, Gaspar-Maia A, Ramalho-Santos M, Reijo Pera RA. High-efficiency stem cell fusion-mediated assay reveals Sall4 as an enhancer of reprogramming. PLoS One 2008; 3:e1955. [PMID: 18414659 PMCID: PMC2278370 DOI: 10.1371/journal.pone.0001955] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 03/02/2008] [Indexed: 01/23/2023] Open
Abstract
Several methods allow reprogramming of differentiated somatic cells to embryonic stem cell-like cells. However, the process of reprogramming remains inefficient and the underlying molecular mechanisms are poorly understood. Here, we report the optimization of somatic cell fusion with embryonic stem cells in order to provide an efficient, quantitative assay to screen for factors that facilitate reprogramming. Following optimization, we achieved a reprogramming efficiency 15–590 fold higher than previous protocols. This allowed observation of cellular events during the reprogramming process. Moreover, we demonstrate that overexpression of the Spalt transcription factor, Sall4, which was previously identified as a regulator of embryonic stem cell pluripotency and early mouse development, can enhance reprogramming. The reprogramming activity of Sall4 is independent of an N-terminal domain implicated in recruiting the nucleosome remodeling and deacetylase corepressor complex, a global transcriptional repressor. These results indicate that improvements in reprogramming assays, including fusion assays, may allow the systematic identification and molecular characterization of enhancers of somatic cell reprogramming.
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Affiliation(s)
- Connie C. Wong
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, San Francisco, California, United States of America
- Institute for Regeneration Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Alexandre Gaspar-Maia
- Institute for Regeneration Medicine, University of California San Francisco, San Francisco, California, United States of America
- Diabetes Center, University of California San Francisco, San Francisco, California, United States of America
- Doctoral Program in Biomedicine and Experimental Biology, Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Miguel Ramalho-Santos
- Institute for Regeneration Medicine, University of California San Francisco, San Francisco, California, United States of America
- Diabetes Center, University of California San Francisco, San Francisco, California, United States of America
- * To whom correspondence should be addressed. E-mail: (MR); (RR)
| | - Renee A. Reijo Pera
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California San Francisco, San Francisco, California, United States of America
- Institute for Regeneration Medicine, University of California San Francisco, San Francisco, California, United States of America
- * To whom correspondence should be addressed. E-mail: (MR); (RR)
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135
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The role of cell differentiation in controlling cell multiplication and cancer. J Cancer Res Clin Oncol 2008; 134:725-41. [DOI: 10.1007/s00432-008-0381-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2007] [Accepted: 03/17/2008] [Indexed: 10/22/2022]
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136
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Abstract
The derivation and study of human embryonic stem cell lines, despite their potential therapeutic usefulness, raise considerable ethical, religious, legal and political concerns because it inevitably leads to the destruction of viable embryos. In an attempt to bridge the division between ethical questions and potential scientific and medical benefits, considerable efforts have been devoted to the search for alternative sources of pluripotent cell lines. In this review we discuss the use of artificial parthenogenesis as a way to create entities, called parthenotes, that may represent an alternative ethical source for pluripotent cell lines. We describe the biological differences between parthenotes and embryos, in order to provide a rationale for the discussion on whether their use can be acceptable as a source of stem cells. We present data derived from animal models on the extent parthenogenetic stem cells are similar to biparental cell lines and discuss these aspects in the context of their extension to the human species. Finally, we present experiments recently carried out in our laboratory that allowed us to generate human parthenotes through artificial activation of human oocytes and to use them as a source for the derivation of parthenogenetic pluripotent cell lines.
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Affiliation(s)
- T A L Brevini
- Laboratory of Biomedical Embryology, Centre for Stem Cell Research, University of Milan, Milan, Italy.
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137
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Kuratomi G, Iwamoto K, Bundo M, Kusumi I, Kato N, Iwata N, Ozaki N, Kato T. Aberrant DNA methylation associated with bipolar disorder identified from discordant monozygotic twins. Mol Psychiatry 2008; 13:429-41. [PMID: 17471289 DOI: 10.1038/sj.mp.4002001] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To search DNA methylation difference between monozygotic twins discordant for bipolar disorder, we applied a comprehensive genome scan method, methylation-sensitive representational difference analysis (MS-RDA) to lymphoblastoid cells derived from the twins. MS-RDA isolated 10 DNA fragments derived from 5' region of known genes/ESTs. Among these 10 regions, four regions showed DNA methylation differences between bipolar twin and control co-twin confirmed by bisulfite sequencing. We performed a case-control study of DNA methylation status of these four regions by pyrosequencing. Two regions, upstream regions of spermine synthase (SMS) and peptidylprolyl isomerase E-like (PPIEL) (CN265253), showed aberrant DNA methylation status in bipolar disorder. SMS, a gene on X chromosome, showed significantly higher DNA methylation level in female patients with bipolar disorder compared with control females. However, there was no difference of mRNA expression. In PPIEL, DNA methylation level was significantly lower in patients with bipolar II disorder than in controls. The expression level of PPIEL was significantly higher in bipolar II disorder than in controls. We found strong inverse correlation between gene expression and DNA methylation levels of PPIEL. These results suggest that altered DNA methylation statuses of PPIEL might have some significance in pathophysiology of bipolar disorder..
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Affiliation(s)
- G Kuratomi
- Laboratory for Molecular Dynamics of Mental Disorders, Brain Science Institute, RIKEN, Hirosawa, Wako, Saitama, Japan
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138
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Goel S, Fujihara M, Minami N, Yamada M, Imai H. Expression of NANOG, but not POU5F1, points to the stem cell potential of primitive germ cells in neonatal pig testis. Reproduction 2008; 135:785-95. [PMID: 18367503 DOI: 10.1530/rep-07-0476] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Gonocytes are primitive germ cells that are present in the neonatal testis and are committed to male germline development. Gonocytes differentiate to spermatogonia, which establish and maintain spermatogenesis in the postnatal testis. However, it is unknown whether large animal species have pluripotency-specific proteins in the testis. Nanog and Pou5f1 (Oct3/4) have been identified as transcription factors essential for maintaining pluripotency of embryonic stem cells in mice. Here, we show that NANOG protein was expressed in the germ cells of neonatal pig testes, but was progressively lost with age. NANOG was expressed in most of the lectin Dolichos biflorus agglutinin- and ZBTB16-positive gonocytes, which are known gonocyte-specific markers in pigs. NANOG was also expressed in Sertoli and interstitial cells of neonatal testes. Interestingly, POU5F1 expression was not detected at either the transcript or the protein level in neonatal pig testis. In the prepubertal testis, NANOG and POU5F1 proteins were primarily detected in differentiated germ cells, such as spermatocytes and spermatids, and rarely in undifferentiated spermatogonia. By using a testis transplantation assay, we found that germ cells from 2- to 4-day-old pigs could colonize and proliferate in the testes of the recipient mice, suggesting that primitive germ cells from neonatal pig testes have stem cell potential.
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Affiliation(s)
- Sandeep Goel
- Laboratory of Reproductive Biology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
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139
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Patra SK, Patra A, Rizzi F, Ghosh TC, Bettuzzi S. Demethylation of (Cytosine-5-C-methyl) DNA and regulation of transcription in the epigenetic pathways of cancer development. Cancer Metastasis Rev 2008; 27:315-34. [DOI: 10.1007/s10555-008-9118-y] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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140
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Patra SK. Ras regulation of DNA-methylation and cancer. Exp Cell Res 2008; 314:1193-201. [PMID: 18282569 DOI: 10.1016/j.yexcr.2008.01.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2007] [Revised: 01/13/2008] [Accepted: 01/16/2008] [Indexed: 01/14/2023]
Abstract
Genome wide hypomethylation and regional hypermethylation of cancer cells and tissues remain a paradox, though it has received a convincing confirmation that epigenetic switching systems, including DNA-methylation represent a fundamental regulatory mechanism that has an impact on genome maintenance and gene transcription. Methylated cytosine residues of vertebrate DNA are transmitted by clonal inheritance through the strong preference of DNA methyltransferase, DNMT1, for hemimethylated-DNA. Maintenance of methylation patterns is necessary for normal development of mice, and aberrant methylation patterns are associated with many human tumours. DNMT1 interacts with many proteins during cell cycle progression, including PCNA, p53, EZH2 and HP1. Ras family of GTPases promotes cell proliferation by its oncogenic nature, which transmits signals by multiple pathways in both lipid raft dependent and independent fashion. DNA-methylation-mediated repression of DNA-repair protein O6-methylguanine DNA methyltransferase (MGMT) gene and increased rate of K-Ras mutation at codon for amino acids 12 and 13 have been correlated with a secondary role for Ras-effector homologues (RASSFs) in tumourigenesis. Lines of evidence suggest that DNA-methylation associated repression of tumour suppressors and apoptotic genes and ceaseless proliferation of tumour cells are regulated in part by Ras-signaling. Control of Ras GTPase signaling might reduce the aberrant methylation and accordingly may reduce the risk of cancer development.
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Affiliation(s)
- Samir Kumar Patra
- Cancer Epigenetics Research, Kalyani (B-7/183), Nadia, West Bengal, India.
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141
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Park JS, Jeong YS, Shin ST, Lee KK, Kang YK. Dynamic DNA methylation reprogramming: active demethylation and immediate remethylation in the male pronucleus of bovine zygotes. Dev Dyn 2007; 236:2523-33. [PMID: 17676637 DOI: 10.1002/dvdy.21278] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
DNA methylation reprogramming (DMR) is believed to be a key process by which mammalian zygotes gain nuclear totipotency through erasing epigenetic modifications acquired during gametogenesis. Nonetheless, DMR patterns do not seem to be conserved among mammals. To identify uniform rules underlying mammalian DMRs, we explored DMRs of diverse mammalian zygotes. Of the zygotes studied, of particular interest was the bovine zygote; the paternal DNA methylation first decreased and was then rapidly restored almost to the maternal methylation level even before the two-cell stage. The 5-azadeoxycytidine treatment led to complete demethylation of the male pronucleus. The unusually dramatic changes in DNA methylation levels indicate that the bovine male pronucleus undergoes active demethylation, which is followed by de novo methylation. Our results show that, in bovine, the compound processes of active DNA demethylation and de novo DNA methylation, along with de novo H3-K9 trimethylation also, take place altogether within this very narrow window of pronucleus development.
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Affiliation(s)
- Jung Sun Park
- Center for Development and Differentiation, KRIBB, Daejon, South Korea
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142
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Shen W, Li L, Bai Z, Pan Q, Ding M, Deng H. In vitro development of mouse fetal germ cells into mature oocytes. Reproduction 2007; 134:223-31. [PMID: 17660232 DOI: 10.1530/rep-06-0378] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Little is known about the mechanisms underlying primordial follicular formation and the acquisition of competence to resume meiosis by growing oocytes. It is therefore important to establish an in vitro experimental model that allows one to study such mechanisms. Mouse follicular development has been studied in vitro over the past several years; however, no evidence has been presented showing that mature oocytes can be obtained from mouse fetal germ cells prior to the formation of primordial follicles. In this study, a method has been established to obtain mature oocytes from the mouse fetal germ cells at 16.5 days postcoitum (dpc). From the initiation of primordial follicular formation to the growth of early secondary follicles, ovarian tissues from 16.5 dpc fetal mice were cultured in vitro for 14 days. Subsequently, 678 intact secondary follicles were isolated from 182 mouse fetal ovaries and cultured for 12 days. A total of 141 oocytes inside antral follicles were matured in vitro, and 102 oocytes underwent germinal vesicle breakdown. We found that 97 oocytes were fertilized and 15 embryos were able to form morula-blastocysts. We also analyzed various genomic imprinting markers and showed that the erasure of genomic imprinting markers in the parental generation was also imposed on the oocytes that developed from fetal germ cells. Our results demonstrate that mouse fetal germ cells are able to form primordial follicles with ovarian cells, and that oocytes within the growing follicles are able to mature normally in vitro.
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Affiliation(s)
- Wei Shen
- College of Animal Science and Technology, Institute of Animal Reproduction Development and Genetic Engineering, Qingdao Agricultural University, Qingdao 266109, China.
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143
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Czarny MJ, Babcock K, Baus RM, Manoharan H, Pitot HC. Hepatocellular carcinomas of the albumin SV40 T-antigen transgenic rat display fetal-like re-expression of lgf2 and deregulation of H19. Mol Carcinog 2007; 46:747-57. [PMID: 17393425 DOI: 10.1002/mc.20286] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Previous studies in our laboratory have shown that one of the earliest events during hepatocarcinogenesis in the albumin SV40 T antigen (Alb SV40 T Ag) transgenic rat is the duplication of chromosome 1q3.7-4.3, a region which contains the imprinted and coordinately regulated genes Igf2 and H19. We have also shown that this duplication is associated with the biallelic expression of the normally monoallelically-expressed H19. These results, however, are seemingly at odds with studies in the mouse that have shown a conservation of fetal regulatory patterns of these two genes in hepatic neoplasms. We therefore aimed in this study to determine the allelic origin of Igf2 expression in hepatocellular carcinomas of the Alb SV40 T Ag transgenic rat. Sprague-Dawley Alb SV40 T Ag transgenic rats and Brown Norway rats were reciprocally mated and the expression of Igf2 in hepatocellular carcinomas of the resulting F(1) transgene-positive female rats was analyzed by Northern blotting and RT-PCR. We determined that Igf2 was expressed exclusively from the paternal allele, which prompted the study (by the same methods) of the allelic origin of H19 in the same hepatocellular carcinomas in order to determine if the two genes remained coordinately regulated. Our results demonstrate fetal-like re-expression of Igf2 and deregulation of H19 in singular hepatocellular carcinomas of the rat. These results imply that another regulatory mechanism other than the generally accepted ICR/CTCF mechanism may play a role in the control of Igf2 and H19 expression.
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MESH Headings
- Albumins/genetics
- Alleles
- Animals
- Animals, Genetically Modified
- Antigens, Polyomavirus Transforming/genetics
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/pathology
- Cell Transformation, Neoplastic/genetics
- Crosses, Genetic
- Female
- Fetus
- Gene Expression Regulation, Neoplastic/genetics
- Insulin-Like Growth Factor Binding Protein 2/metabolism
- Liver Neoplasms, Experimental/genetics
- Liver Neoplasms, Experimental/pathology
- Polymorphism, Single Nucleotide
- RNA, Long Noncoding
- RNA, Untranslated/genetics
- RNA, Untranslated/metabolism
- Rats
- Rats, Inbred BN
- Rats, Sprague-Dawley
- Sequence Analysis, DNA
- Transgenes
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Affiliation(s)
- Matthew J Czarny
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53706, USA
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144
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Nafee TM, Farrell WE, Carroll WD, Fryer AA, Ismail KMK. Review article: Epigenetic control of fetal gene expression. BJOG 2007; 115:158-68. [DOI: 10.1111/j.1471-0528.2007.01528.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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145
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Abstract
Postnatal skeletal stem cells are a subpopulation of the bone marrow stromal cell network. To date, the most straightforward way of assessing the activity of skeletal stem cells within the bone marrow stromal cell (BMSC) population is via analysis of the rapidly adherent, colony-forming unit-fibroblast (CFU-F), and their progeny, BMSCs. Several in vitro methods are employed to determine the differentiation capacity of BMSCs, using osteogenic and adipogenic "cocktails" and staining protocols, and pellet cell culture for chondrogenic differentiation. However, true differentiation potential is best determined by in vivo transplantation in either closed or open systems. By in vivo transplantation, approximately 10% of the clonal strains are able to form bone, stroma, and marrow adipocytes, and are true skeletal stem cells. Furthermore, when derived from patients or animal models with abnormalities in gene expression, they recapitulate the disease phenotype on in vivo transplantation. Although ex vivo expansion of BMSCs inevitably dilutes the skeletal stem cells, when used en masse, they are attractive candidates for reconstruction of segmental bone defects, and as targets for gene therapy.
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Affiliation(s)
- Paolo Bianco
- Department of Experimental Medicine and Pathology, La Sapienza University, Rome, Italy
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146
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Kucia M, Zuba-Surma EK, Wysoczynski M, Wu W, Ratajczak J, Machalinski B, Ratajczak MZ. Adult marrow-derived very small embryonic-like stem cells and tissue engineering. Expert Opin Biol Ther 2007; 7:1499-514. [PMID: 17916043 DOI: 10.1517/14712598.7.10.1499] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A population of CXCR4(+) lin(-) CD45(-) cells that express SSEA, Oct-4 and Nanog has been identified in adult bone marrow. These cells are very small and display several features typical for primary embryonic stem cells such as: i) a large nuclei surrounded by a narrow rim of cytoplasm; ii) open-type chromatin (euchromatin); and iii) high telomerase activity. These cells were named very small embryonic-like stem cells (VSEL-SC). The authors hypothesized that they are direct descendants of the germ lineage. Germ lineage, in order to pass genes on to the next generation, has to create soma and thus becomes a 'mother lineage' for all somatic cell lineages present in the adult body. Germ potential is established after conception in a totipotent zygote and retained subsequently during development in blastomers of morula, cells form the inner cell mass of blastocyst, epiblast and population of primordial germ cells. The authors envision that VSEL-SC are epiblast-derived pluripotent stem cells and could potentially become a less-controversial source of stem cells for regeneration.
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Affiliation(s)
- Magda Kucia
- University of Louisville, Stem Cell Institute at James Graham Brown Cancer Center, 500 South Floyd Street, Louisville, KY 40202, USA
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147
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Georgiou I, Pardalidis N, Giannakis D, Saito M, Watanabe T, Tsounapi P, Loutradis D, Kanakas N, Karagiannis A, Baltogiannis D, Giotitsas N, Miyagawa I, Sofikitis N. In vitro spermatogenesis as a method to bypass pre-meiotic or post-meiotic barriers blocking the spermatogenetic process: genetic and epigenetic implications in assisted reproductive technology. Andrologia 2007; 39:159-76. [PMID: 17714214 DOI: 10.1111/j.1439-0272.2007.00778.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Pregnancies achieved by assisted reproduction technologies and particularly by ooplasmic injections of either in vivo or in vitro generated immature male germ cells are susceptible to genetic risks inherent to the male population treated with assisted reproduction and additional risks inherent to these innovative procedures. The documented, as well as the theoretical risks, are discussed in this review. These risks represent mainly the consequences of genetic abnormalities underlying male infertility and may become stimulators for the development of novel approaches and applications in the treatment of infertility. Recent data suggest that techniques employed for in vitro spermatogenesis, male somatic cell haploidization, stem cell differentiation in vitro and assisted reproductive technology may also affect the epigenetic characteristics of the male gamete, the female gamete, or may have an impact on early embryogenesis. They may be also associated with an increased risk for genomic imprinting abnormalities. Production of haploid male gametes in vitro may not allow the male gamete to undergo all the genetic and epigenetic alterations that the male gamete normally undergoes during in vivo spermatogenesis.
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Affiliation(s)
- I Georgiou
- Laboratory of Molecular Urology and Genetics of Human Reproduction, Department of Urology, Ioannina University School of Medicine, Ioannina, Greece
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148
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Edwards TM, Myers JP. Environmental exposures and gene regulation in disease etiology. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:1264-70. [PMID: 17805414 PMCID: PMC1964917 DOI: 10.1289/ehp.9951] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Accepted: 05/21/2007] [Indexed: 05/17/2023]
Abstract
OBJECTIVE Health or disease is shaped for all individuals by interactions between their genes and environment. Exactly how the environment changes gene expression and how this can lead to disease are being explored in a fruitful new approach to environmental health research, representative studies of which are reviewed here. DATA SOURCES We searched Web of Science and references of relevant publications to understand the diversity of gene regulatory mechanisms affected by environmental exposures with disease implications. DATA SYNTHESIS Pharmaceuticals, pesticides, air pollutants, industrial chemicals, heavy metals, hormones, nutrition, and behavior can change gene expression through a broad array of gene regulatory mechanisms. Mechanisms include regulation of gene translocation, histone modifications, DNA methylation, DNA repair, transcription, RNA stability, alternative RNA splicing, protein degradation, gene copy number, and transposon activation. Furthermore, chemically induced changes in gene regulation are associated with serious and complex human diseases, including cancer, diabetes and obesity, infertility, respiratory diseases, allergies, and neurodegenerative disorders such as Parkinson and Alzheimer diseases. One of the best-studied areas of gene regulation is epigenetics, especially DNA methylation. Our examples of environmentally induced changes in DNA methylation are presented in the context of early development, when methylation patterns are initially laid down. This approach highlights the potential role for altered DNA methylation in fetal origins of adult disease and inheritance of acquired genetic change. CONCLUSIONS The reviewed studies indicate that genetic predisposition for disease is best predicted in the context of environmental exposures. Second, the genetic mechanisms investigated in these studies offer new avenues for risk assessment research. Finally, we are likely to witness dramatic improvements in human health, and reductions in medical costs, if environmental pollution is decreased.
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Affiliation(s)
- Thea M Edwards
- Department of Zoology, University of Florida, Gainesville, Florida 32611, USA.
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149
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Raju Bagadi SA, Kaur J, Ralhan R. Establishment and characterisation of two novel breast cancer cell lines. Cell Biol Int 2007; 32:55-65. [PMID: 17959394 DOI: 10.1016/j.cellbi.2007.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 08/13/2007] [Accepted: 08/22/2007] [Indexed: 11/26/2022]
Abstract
Two novel oestrogen receptor (ER) negative breast cancer cell lines, BCa-11 (familial) and BCa-15 (sporadic) were successfully established from primary tumours. Characterisation of these cell lines showed expression of epithelial specific antigen and cytokeratins confirming their epithelial lineage. Analysis of ultrastructure and anchorage independent growth confirmed the epithelial nature and transformed phenotype of these cells. Both cell lines showed loss of pRb, Dab2 and ERalpha and elevated levels of proliferation marker Ki67. In addition, BCa-11 cells showed loss of HOXA5, tumour suppressor genes p16(INK4A) and RARbeta as well as overexpression of CyclinD1. Elevation of DNMT1 and DNMT3B transcript levels, promoter hypermethylation of RASSF1A, RARbeta2, and HOXA5 further support their neoplastic origin. In conclusion, the two ERalpha negative breast cancer cell lines established herein have certain useful characteristics that may make them valuable for understanding the mechanism of oestrogen receptor negative breast tumours and testing new drugs.
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150
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Abstract
It has been postulated that mammalian nuclear transfer (NT) cloning efficiency is inversely correlated with donor cell differentiation status. To test this hypothesis, we compared genetically identical and increasingly differentiated donors within the myogenic lineage. Bovine male fetal muscle cells were cultured for 1-6 days in vitro. The proportion of cells displaying the following antigens was quantified by immunofluorescence microscopy: MYOD1, MYF5, PAX7, MYOG, DES, MYH, and 5-Bromo-2-deoxyuridine. Based on the antigen profile of both bulk populations and individually size-selected cells prepared for NT, donors serum-starved for 1, 4, and 5 days were classified as myogenic precursors (MPCs), myotubes (MTs), and muscle-derived fibroblasts (MFs) with purities of 92%, 85%, and 99%, respectively. Expression of the following transcripts was measured by RT-PCR in 1) cells selected for NT, 2) metaphase II oocytes, 3) NT couplets, 4) NT reconstructs, 5) NT two-cell embryos, and 6) NT blastocysts: MYOD1, MYF5, PAX7, MYOG, MYF6, ACTB, and 18S rRNA. Muscle-specific genes were silenced and remained undetectable up to the blastocyst stage, whereas housekeeping genes 18S and ACTB continued to be expressed. Differentiation status affected development to transferable embryos (118 [23%] of 520 vs. 93 [11%] of 873 vs. 66 [38%] of 174 for MPC vs. MT vs. MF, respectively, P < 0.001). However, there were no significant differences in pregnancy rate and development to weaning between the cell types (pregnancy rate: 14 [64%] of 22 vs. 8 [35%] of 23 vs. 10 [45%] of 22, and development: 4 [18%] of 22 vs. 2 [9%] of 23 vs. 3 [14%] of 22 for MPC vs. MT vs. MF, respectively).
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Affiliation(s)
- A L Green
- Ruakura Research Centre, Reproductive Technologies, AgResearch Ltd., Hamilton, New Zealand
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