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Cofre J, Abdelhay E. Cancer Is to Embryology as Mutation Is to Genetics: Hypothesis of the Cancer as Embryological Phenomenon. ScientificWorldJournal 2017; 2017:3578090. [PMID: 28553657 PMCID: PMC5434308 DOI: 10.1155/2017/3578090] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/20/2017] [Indexed: 01/20/2023] Open
Abstract
Despite numerous advances in cell biology, genetics, and developmental biology, cancer origin has been attributed to genetic mechanisms primarily involving mutations. Embryologists have expressed timidly cancer embryological origin with little success in leveraging the discussion that cancer could involve a set of conventional cellular processes used to build the embryo during morphogenesis. Thus, this "cancer process" allows the harmonious and coherent construction of the embryo structural base, and its implementation as the embryonic process involves joint regulation of differentiation, proliferation, cell invasion, and migration, enabling the human being recreation of every generation. On the other hand, "cancer disease" is the representation of an abnormal state of the cell that might happen in the stem cells of an adult person, in which the mechanism for joint gene regulating of differentiation, proliferation, cell invasion, and migration could be reactivated in an entirely inappropriate context.
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Affiliation(s)
- Jaime Cofre
- Laboratório de Embriologia Molecular e Câncer, Universidade Federal de Santa Catarina, Sala 313b, 88040-900 Florianópolis, SC, Brazil
| | - Eliana Abdelhay
- Divisão de Laboratórios do CEMO, Instituto Nacional do Câncer, Rio de Janeiro, RJ, Brazil
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3
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Houston DW. Vertebrate Axial Patterning: From Egg to Asymmetry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 953:209-306. [PMID: 27975274 PMCID: PMC6550305 DOI: 10.1007/978-3-319-46095-6_6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The emergence of the bilateral embryonic body axis from a symmetrical egg has been a long-standing question in developmental biology. Historical and modern experiments point to an initial symmetry-breaking event leading to localized Wnt and Nodal growth factor signaling and subsequent induction and formation of a self-regulating dorsal "organizer." This organizer forms at the site of notochord cell internalization and expresses primarily Bone Morphogenetic Protein (BMP) growth factor antagonists that establish a spatiotemporal gradient of BMP signaling across the embryo, directing initial cell differentiation and morphogenesis. Although the basics of this model have been known for some time, many of the molecular and cellular details have only recently been elucidated and the extent that these events remain conserved throughout vertebrate evolution remains unclear. This chapter summarizes historical perspectives as well as recent molecular and genetic advances regarding: (1) the mechanisms that regulate symmetry-breaking in the vertebrate egg and early embryo, (2) the pathways that are activated by these events, in particular the Wnt pathway, and the role of these pathways in the formation and function of the organizer, and (3) how these pathways also mediate anteroposterior patterning and axial morphogenesis. Emphasis is placed on comparative aspects of the egg-to-embryo transition across vertebrates and their evolution. The future prospects for work regarding self-organization and gene regulatory networks in the context of early axis formation are also discussed.
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Affiliation(s)
- Douglas W Houston
- Department of Biology, The University of Iowa, 257 BB, Iowa City, IA, 52242, USA.
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Shi J, Chen Q, Li X, Zheng X, Zhang Y, Qiao J, Tang F, Tao Y, Zhou Q, Duan E. Dynamic transcriptional symmetry-breaking in pre-implantation mammalian embryo development revealed by single-cell RNA-seq. Development 2015; 142:3468-77. [PMID: 26395495 DOI: 10.1242/dev.123950] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 08/17/2015] [Indexed: 12/19/2022]
Abstract
During mammalian pre-implantation embryo development, when the first asymmetry emerges and how it develops to direct distinct cell fates remain longstanding questions. Here, by analyzing single-blastomere transcriptome data from mouse and human pre-implantation embryos, we revealed that the initial blastomere-to-blastomere biases emerge as early as the first embryonic cleavage division, following a binomial distribution pattern. The subsequent zygotic transcriptional activation further elevated overall blastomere-to-blastomere biases during the two- to 16-cell embryo stages. The trends of transcriptional asymmetry fell into two distinct patterns: for some genes, the extent of asymmetry was minimized between blastomeres (monostable pattern), whereas other genes, including those known to be lineage specifiers, showed ever-increasing asymmetry between blastomeres (bistable pattern), supposedly controlled by negative or positive feedbacks. Moreover, our analysis supports a scenario in which opposing lineage specifiers within an early blastomere constantly compete with each other based on their relative ratio, forming an inclined 'lineage strength' that pushes the blastomere onto a predisposed, yet flexible, lineage track before morphological distinction.
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Affiliation(s)
- Junchao Shi
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Qi Chen
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Xin Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Xiudeng Zheng
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Ying Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Jie Qiao
- Biodynamic Optical Imaging Center and Center for Reproductive Medicine, College of Life Sciences, Third Hospital, Peking University, 100871 Beijing, China
| | - Fuchou Tang
- Biodynamic Optical Imaging Center and Center for Reproductive Medicine, College of Life Sciences, Third Hospital, Peking University, 100871 Beijing, China
| | - Yi Tao
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Enkui Duan
- State Key Laboratory of Stem Cell and Reproductive Biology, Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 100101 Beijing, China
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5
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Takaoka K, Hamada H. Origin of cellular asymmetries in the pre-implantation mouse embryo: a hypothesis. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0536. [PMID: 25349445 DOI: 10.1098/rstb.2013.0536] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The first cell fate decision during mouse development concerns whether a blastomere will contribute to the inner cell mass (ICM; which gives rise to the embryo proper) or to trophectoderm (TE; which gives rise to the placenta). The position of a cell within an 8- to 16-cell-stage embryo correlates with its future fate, with outer cells contributing to TE and inner cells to the ICM. It remains unknown, however, whether an earlier pre-pattern exists. Here, we propose a hypothesis that could account for generation of such a pre-pattern and which is based on epigenetic asymmetry (such as in histone or DNA methylation) between maternal and paternal genomes in the zygote.
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Affiliation(s)
- Katsuyoshi Takaoka
- Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-oka, Suita, Osaka 565-0871, Japan CREST, Japan Science and Technology Corporation (JST), Osaka University, 1-3 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Hiroshi Hamada
- Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-oka, Suita, Osaka 565-0871, Japan CREST, Japan Science and Technology Corporation (JST), Osaka University, 1-3 Yamada-oka, Suita, Osaka 565-0871, Japan
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Inhibition of RHO-ROCK signaling enhances ICM and suppresses TE characteristics through activation of Hippo signaling in the mouse blastocyst. Dev Biol 2014; 394:142-55. [PMID: 24997360 DOI: 10.1016/j.ydbio.2014.06.023] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 06/21/2014] [Accepted: 06/24/2014] [Indexed: 12/14/2022]
Abstract
Specification of the trophectoderm (TE) and inner cell mass (ICM) lineages in the mouse blastocyst correlates with cell position, as TE derives from outer cells whereas ICM from inner cells. Differences in position are reflected by cell polarization and Hippo signaling. Only in outer cells, the apical-basal cell polarity is established, and Hippo signaling is inhibited in such a manner that LATS1 and 2 (LATS1/2) kinases are prevented from phosphorylating YAP, a key transcriptional co-activator of the TE-specifying gene Cdx2. However, the molecular mechanisms that regulate these events are not fully understood. Here, we showed that inhibition of RHO-ROCK signaling enhances ICM and suppresses TE characteristics through activation of Hippo signaling and disruption of apical-basal polarity. Embryos treated with ROCK inhibitor Y-27632 exhibited elevated expression of ICM marker NANOG and reduced expression of CDX2 at the blastocyst stage. Y-27632-treated embryos failed to accumulate YAP in the nucleus, although it was rescued by concomitant inhibition of LATS1/2. Segregation between apical and basal polarity regulators, namely PARD6B, PRKCZ, SCRIB, and LLGL1, was dampened by Y-27632 treatment, whereas some of the polarization events at the late 8-cell stage such as compaction and apical localization of p-ERM and tyrosinated tubulin occurred normally. Similar abnormalities of Hippo signaling and apical-basal polarization were also observed in embryos that were treated with RHO GTPases inhibitor. These results suggest that RHO-ROCK signaling plays an essential role in regulating Hippo signaling and cell polarization to enable proper specification of the ICM and TE lineages.
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Hirate Y, Hirahara S, Inoue KI, Suzuki A, Alarcon VB, Akimoto K, Hirai T, Hara T, Adachi M, Chida K, Ohno S, Marikawa Y, Nakao K, Shimono A, Sasaki H. Polarity-dependent distribution of angiomotin localizes Hippo signaling in preimplantation embryos. Curr Biol 2013; 23:1181-94. [PMID: 23791731 DOI: 10.1016/j.cub.2013.05.014] [Citation(s) in RCA: 286] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/07/2013] [Accepted: 05/08/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND In preimplantation mouse embryos, the first cell fate specification to the trophectoderm or inner cell mass occurs by the early blastocyst stage. The cell fate is controlled by cell position-dependent Hippo signaling, although the mechanisms underlying position-dependent Hippo signaling are unknown. RESULTS We show that a combination of cell polarity and cell-cell adhesion establishes position-dependent Hippo signaling, where the outer and inner cells are polar and nonpolar, respectively. The junction-associated proteins angiomotin (Amot) and angiomotin-like 2 (Amotl2) are essential for Hippo pathway activation and appropriate cell fate specification. In the nonpolar inner cells, Amot localizes to adherens junctions (AJs), and cell-cell adhesion activates the Hippo pathway. In the outer cells, the cell polarity sequesters Amot from basolateral AJs to apical domains, thereby suppressing Hippo signaling. The N-terminal domain of Amot is required for actin binding, Nf2/Merlin-mediated association with the E-cadherin complex, and interaction with Lats protein kinase. In AJs, S176 in the N-terminal domain of Amot is phosphorylated by Lats, which inhibits the actin-binding activity, thereby stabilizing the Amot-Lats interaction to activate the Hippo pathway. CONCLUSIONS We propose that the phosphorylation of S176 in Amot is a critical step for activation of the Hippo pathway in AJs and that cell polarity disconnects the Hippo pathway from cell-cell adhesion by sequestering Amot from AJs. This mechanism converts positional information into differential Hippo signaling, thereby leading to differential cell fates.
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Affiliation(s)
- Yoshikazu Hirate
- Department of Cell Fate Control, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
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