scholarly journals Dynamic determinations: patterning the cell behaviours that close the amphibian blastopore

2008 ◽  
Vol 363 (1495) ◽  
pp. 1317-1332 ◽  
Author(s):  
Ray Keller ◽  
David Shook
Keyword(s):  
Marginal Zone ◽  
Epithelial Mesenchymal Transition ◽  
The Body ◽  
Dynamic Features ◽  
Cell Behaviour ◽  
Mesenchymal Transition ◽  
Tissue Organization ◽  
Hoop Stresses ◽  
Cell Intercalation ◽  
Anterior Posterior

We review the dynamic patterns of cell behaviours in the marginal zone of amphibians with a focus on how the progressive nature and the geometry of these behaviours drive blastopore closure. Mediolateral cell intercalation behaviour and epithelial–mesenchymal transition are used in different combinations in several species of amphibian to generate a conserved pattern of circumblastoporal hoop stresses. Although these cell behaviours are quite different and involve different germ layers and tissue organization, they are expressed in similar patterns. They are expressed progressively along presumptive lateral–medial and anterior–posterior axes of the body plan in highly ordered geometries of functional significance in the context of the biomechanics of blastopore closure, thereby accounting for the production of similar patterns of circumblastoporal forces. It is not the nature of the cell behaviour alone, but the context, the biomechanical connectivity and spatial and temporal pattern of its expression that determine specificity of morphogenic output during gastrulation and blastopore closure. Understanding the patterning of these dynamic features of cell behaviour is important and will require analysis of signalling at much greater spatial and temporal resolution than that has been typical in the analysis of patterning tissue differentiation.

scholarly journals Epithelial-Mesenchymal Transition and Metastasis under the Control of Transforming Growth Factor β

2018 ◽  
Vol 19 (11) ◽  
pp. 3672 ◽  
Author(s):  
Yutaro Tsubakihara ◽  
Aristidis Moustakas
Keyword(s):  
Growth Factor ◽  
Tumor Cells ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Transforming Growth Factor Β ◽  
Basement Membranes ◽  
The Body ◽  
Common Denominator ◽  
Adhesion Forces ◽  
Mesenchymal Transition

Metastasis of tumor cells from primary sites of malignancy to neighboring stromal tissue or distant localities entails in several instances, but not in every case, the epithelial-mesenchymal transition (EMT). EMT weakens the strong adhesion forces between differentiated epithelial cells so that carcinoma cells can achieve solitary or collective motility, which makes the EMT an intuitive mechanism for the initiation of tumor metastasis. EMT initiates after primary oncogenic events lead to secondary secretion of cytokines. The interaction between tumor-secreted cytokines and oncogenic stimuli facilitates EMT progression. A classic case of this mechanism is the cooperation between oncogenic Ras and the transforming growth factor β (TGFβ). The power of TGFβ to mediate EMT during metastasis depends on versatile signaling crosstalk and on the regulation of successive waves of expression of many other cytokines and the progressive remodeling of the extracellular matrix that facilitates motility through basement membranes. Since metastasis involves many organs in the body, whereas EMT affects carcinoma cell differentiation locally, it has frequently been debated whether EMT truly contributes to metastasis. Despite controversies, studies of circulating tumor cells, studies of acquired chemoresistance by metastatic cells, and several (but not all) metastatic animal models, support a link between EMT and metastasis, with TGFβ, often being a common denominator in this link. This article aims at discussing mechanistic cases where TGFβ signaling and EMT facilitate tumor cell dissemination.

scholarly journals A Role of Tumor-Released Exosomes in Paracrine Dissemination and Metastasis

2018 ◽  
Vol 19 (12) ◽  
pp. 3968 ◽  
Author(s):  
Enrico Spugnini ◽  
Mariantonia Logozzi ◽  
Rossella Di Raimo ◽  
Davide Mizzoni ◽  
Stefano Fais
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Malignant Tumors ◽  
The Body ◽  
Mesenchymal Transition ◽  
Metastatic Cascade ◽  
Target Organs

Metastatic diffusion is thought to be a multi-step phenomenon involving the release of cells from the primary tumor and their diffusion through the body. Currently, several hypotheses have been put forward in order to explain the origin of cancer metastasis, including epithelial–mesenchymal transition, mutagenesis of stem cells, and a facilitating role of macrophages, involving, for example, transformation or fusion hybridization with neoplastic cells. In this paradigm, tumor-secreted extracellular vesicles (EVs), such as exosomes, play a pivotal role in cell communications, delivering a plethora of biomolecules including proteins, lipids, and nucleic acids. For their natural role in shuttling molecules, EVs have been newly considered a part of the metastatic cascade. They have a prominent role in preparing the so-called “tumor niches” in target organs. However, recent evidence has pointed out an even more interesting role of tumor EVs, consisting in their ability to induce malignant transformation in resident mesenchymal stem cells. All in all, in this review, we discuss the multiple involvements of EVs in the metastatic cascade, and how we can exploit and manipulate EVs in order to reduce the metastatic spread of malignant tumors.

scholarly journals ALKBH5 Inhibits Pancreatic Cancer Motility by Decreasing Long Non-Coding RNA KCNK15-AS1 Methylation

2018 ◽  
Vol 48 (2) ◽  
pp. 838-846 ◽  
Author(s):  
Yuan He ◽  
Hao Hu ◽  
Yandong Wang ◽  
Hao Yuan ◽  
Zipeng Lu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Epithelial Mesenchymal Transition ◽  
The Body ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Cancer Pathogenesis ◽  
Non Coding Rna ◽  
Cancer Tissues ◽  
Long Non Coding Rna

Background/Aims: Mounting evidence suggests that epitranscriptional modifications regulate multiple cellular processes. N6-Methyladenosine (m6A), the most abundant reversible methylation of mRNA, has critical roles in cancer pathogenesis. However, the mechanisms and functions of long non-coding RNA (lncRNA) methylation remain unclear. Pancreatic cancer resulted in 411,600 deaths globally in 2015. By the time of pancreatic cancer diagnosis, metastasis has often occurred in other parts of the body. The present study sought to investigate lncRNA m6A modification and its roles in pancreatic cancer. Methods: Differential expression between cancer cells and matched normal cells was evaluated to identify candidate lncRNAs. The lncRNA KCNK15-AS1 was detected in cancer tissues and various pancreatic cells using RT-qPCR. KCNK15-AS1 was transfected into cells to explore its role in migration and invasion. Then, m6A RNA immunoprecipitation was performed to detect methylated KCNK15-AS1 in tissues and cells. Epithelial–mesenchymal transition (EMT) markers were used to evaluate KCNK15-AS1-mediated EMT processes. Results: KCNK15-AS1 was downregulated in pancreatic cancer tissues compared with paired adjacent normal tissues. KCNK15-AS1 inhibited migration and invasion in MIA PaCa-2 and BxPC-3 cells. Furthermore, total RNA methylation in cancer cells was significantly enriched relative to that in immortalized human pancreatic duct epithelial (HPDE6-C7) cells. In addition, the m6A eraser ALKBH5 was downregulated in cancer cells, which can demethylate KCNK15-AS1 and regulate KCNK15-AS1-mediated cell motility. Conclusion: Our results have revealed a novel mechanism by which ALKBH5 inhibits pancreatic cancer motility by demethylating lncRNA KCNK15-AS1, identifying a potential therapeutic target for pancreatic cancer.

Breast Cancer Metastasis: Role of Tumor Microenvironment and Resident Macropahges

2016 ◽  
Vol 1 (1) ◽  
pp. 48
Author(s):  
Khemraj Singh Baghel ◽  
Smrati Bhadauria
Keyword(s):  
Breast Cancer ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Metastatic Breast ◽  
Breast Cancer Metastasis ◽  
The Body ◽  
Tissue Remodelling ◽  
Mesenchymal Transition

Metastatic breast cancer is a stage of breast cancer wherever the disease has spread to distant parts of the body. Onset of metastasis is one of the biggest obstacles to the successful treatment of cancer. The potential of a tumor cell to metastasize profoundly depends on its microenvironment, or “niche” interactions with local components. Macrophages provide tropic support to tumors. Resident macrophages contribute a set of common functions, including their capability to defend against microbial infections, to maintain normal cell turnover and tissue remodelling, and to help repair sites of injury. Macrophages are recruited into the tumor microenvironment where they differentiate to become Tumor-associated-macrophages (TAMs). TAMs are the most abundant subpopulation of tumor-stroma and actively drive cancer cell invasion and metastasis. Cancer metastasis is not solely regulated by the deregulation of metastasis promoting or suppressing genes in cancer cells. Recently the interaction between the stromal cells and cancer cells has been demonstrated to promote cancer metastasis. TAMs can advocate epithelial-mesenchymal transition of cancer cells. Loss of e-cadherin, a major phenomenon of epithelial to mesenchymal transition (EMT), reduces adhesiveness and releases cancer cells to distant (secondary) sites. A positive correlation between tumor progression and the expression of matrix metallo proteinases (MMPs) in tumor tissues has been demonstrated in numerous human and animal studies. The dynamic interactions of cancer-cells with TAMs actively promote invasion-metastasis cascade through intercellular-signalling-networks that need better elucidation.

scholarly journals Epithelial–mesenchymal transition: role in cancer progression and the perspectives of antitumor treatment

Acta Naturae ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 4-23
Author(s):  
A. V. Gaponova ◽  
S. Rodin ◽  
A. A. Mazina ◽  
P. V. Volchkov
Keyword(s):  
Epithelial Cells ◽  
Tumor Progression ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Malignant Tumors ◽  
The Body ◽  
Epithelial Tissue ◽  
Mesenchymal Transition ◽  
Tumor Dissemination

About 90% of all malignant tumors are of epithelial nature. The epithelial tissue is characterized by a close interconnection between cells through cellcell interactions, as well as a tight connection with the basement membrane, which is responsible for cell polarity. These interactions strictly determine the location of epithelial cells within the body and are seemingly in conflict with the metastatic potential that many cancers possess (the main criteria for highly malignant tumors). Tumor dissemination into vital organs is one of the primary causes of death in patients with cancer. Tumor dissemination is based on the so-called epithelialmesenchymal transition (EMT), a process when epithelial cells are transformed into mesenchymal cells possessing high mobility and migration potential. More and more studies elucidating the role of the EMT in metastasis and other aspects of tumor progression are published each year, thus forming a promising field of cancer research. In this review, we examine the most recent data on the intracellular and extracellular molecular mechanisms that activate EMT and the role they play in various aspects of tumor progression, such as metastasis, apoptotic resistance, and immune evasion, aspects that have usually been attributed exclusively to cancer stem cells (CSCs). In conclusion, we provide a detailed review of the approved and promising drugs for cancer therapy that target the components of the EMT signaling pathways.

scholarly journals Wei Chang an Pill Alleviates TNBS-induced Ulcerative Colitis Through Inhibition of EMTProcess

2021 ◽  
Author(s):  
Yaxin Qi ◽  
Lijuan Chai ◽  
Min Zhang ◽  
Sitong Jia ◽  
Lin Wang ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Body Weight ◽  
Epithelial Mesenchymal Transition ◽  
Activity Index ◽  
Pharmaceutical Preparation ◽  
Damage Index ◽  
The Body ◽  
Active Ingredients ◽  
Mesenchymal Transition ◽  
Anti Inflammatory

Abstract Background: Wei Chang An pill (WCA) is a traditional Chinese pharmaceutical preparation which has been widely used to treat various gastrointestinal diseases including Ulcerative colitis (UC). The aim of our study was investigate the inhibitory effect and mechanism of WCA in the treatment of 2,4,6-trinitro-benzenesulfonic acid (TNBS)-induced UC in rats.Methods: We established the TNBS-induced UC model and then WCA was administrated orally for one week. Body weight, colon lengths, Disease Activity Index (DAI) score and Colon Mucosa Damage Index (CMDI) score were recorded. The expression of cytokines factors in LPS-stimulated THP-1 cells was recorded to evaluate the anti-inflammatory effects of WCA and its herb active ingredients. Immunohistochemistry and immunofluorescence were used to evaluate the Epithelial-Mesenchymal Transition (EMT) process in UC rats and Caco-2 cells which were induced by LPS-stimulated THP-1 cells uponWCA treatment.Results: WCA significantly decreased the body weight loss, higher DAI and CMDI score, colon length shortening and histological damage in UC rats. Furthermore, both of the activities of myeloperoxidase dismutase (MPO) and the mRNA expressions of cytokine in UC tissues were significantly inhibited. In THP-1 cells, the mRNA expressions of IP-10, TNF-α, IL-6 and IkBα were significantly suppressed by WCA or its active ingredients. In UC rats and Caco-2 cells, both of their EMT process were strongly suppressed by WCA.Conclusion: These results show that through improving inflammatory microenvironment to inhibit the EMT process, WCA retarded the development of UC in rats to play its anti-inflammatory effect.

scholarly journals Crotoxin Modulates Events Involved in Epithelial–Mesenchymal Transition in 3D Spheroid Model

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 830
Author(s):  
Ellen Emi Kato ◽  
Sandra Coccuzzo Sampaio
Keyword(s):  
Tumor Cells ◽  
Type I Collagen ◽  
Epithelial Mesenchymal Transition ◽  
Metastatic Cancer ◽  
A549 Cells ◽  
The Body ◽  
Antitumor Action ◽  
Type I ◽  
Collagen Gels ◽  
Mesenchymal Transition

Epithelial–mesenchymal transition (EMT) occurs in the early stages of embryonic development and plays a significant role in the migration and the differentiation of cells into various types of tissues of an organism. However, tumor cells, with altered form and function, use the EMT process to migrate and invade other tissues in the body. Several experimental (in vivo and in vitro) and clinical trial studies have shown the antitumor activity of crotoxin (CTX), a heterodimeric phospholipase A2 present in the Crotalus durissus terrificus venom. In this study, we show that CTX modulates the microenvironment of tumor cells. We have also evaluated the effect of CTX on the EMT process in the spheroid model. The invasion of type I collagen gels by heterospheroids (mix of MRC-5 and A549 cells constitutively prepared with 12.5 nM CTX), expression of EMT markers, and secretion of MMPs were analyzed. Western blotting analysis shows that CTX inhibits the expression of the mesenchymal markers, N-cadherin, α-SMA, and αv. This study provides evidence of CTX as a key modulator of the EMT process, and its antitumor action can be explored further for novel drug designing against metastatic cancer.

Microtubule disruption reveals that Spemann's organizer is subdivided into two domains by the vegetal alignment zone

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 895-906 ◽  
Author(s):  
M.C. Lane ◽  
R. Keller
Keyword(s):  
Marginal Zone ◽  
Axis Formation ◽  
Convergent Extension ◽  
Microtubule Depolymerization ◽  
Microtubule Disruption ◽  
Spemann's Organizer ◽  
And Function ◽  
Cell Intercalation ◽  
Somitic Mesoderm ◽  
Anterior Posterior

Mediolateral cell intercalation is proposed to drive morphogenesis of the primary embryonic axis in Xenopus. Mediolateral intercalation begins in a group of cells called the vegetal alignment zone, a subpopulation of cells in Spemann's organizer, and spreads through much of the marginal zone. To understand the functions of the vegetal alignment zone during gastrulation and axis formation, we have inhibited its formation by disrupting microtubules with nocodazole in early gastrula embryos. In such embryos, mediolateral intercalation, involution and convergent extension of the marginal zone do not occur. Although cell motility continues, and the anterior notochordal and somitic mesoderm differentiate in the pre-involution marginal zone, posterior notochordal and somitic mesoderm do not differentiate. In contrast, microtubule depolymerization in midgastrula embryos, after the vegetal alignment zone has formed, does not inhibit mediolateral cell intercalation, involution and convergent extension, or differentiation of posterior notochord and somites. We conclude that microtubules are required only for orienting and polarizing at stage 101/2 the first cells that undergo mediolateral intercalation and form the vegetal alignment zone, and not for subsequent morphogenesis. These results demonstrate that microtubules are required to form the vegetal alignment zone, and that both microtubules and the vegetal alignment zone play critical roles in the inductive and morphogenetic activities of Spemann's organizer. In addition, our results suggest that Spemann's organizer contains multiple organizers, which act in succession and change their location and function during gastrulation to generate the anterior/posterior axis in Xenopus.

scholarly journals Epithelial-Mesenchymal Transition (EMT) as a Therapeutic Target

2021 ◽  
pp. 1-26
Author(s):  
Sven Jonckheere ◽  
Jamie Adams ◽  
Dominic De Groote ◽  
Kyra Campbell ◽  
Geert Berx ◽  
...  
Keyword(s):  
Cancer Cells ◽  
High Throughput Screening ◽  
Drug Targets ◽  
Epithelial Mesenchymal Transition ◽  
Primary Tumour ◽  
Therapy Resistance ◽  
Therapeutic Strategies ◽  
The Body ◽  
Screening Tools ◽  
Mesenchymal Transition

Metastasis is the spread of cancer cells from the primary tumour to distant sites and organs throughout the body. It is the primary cause of cancer morbidity and mortality, and is estimated to account for 90% of cancer-related deaths. During the initial steps of the metastatic cascade, epithelial cancer cells undergo an epithelial-mesenchymal transition (EMT), and as a result become migratory and invasive mesenchymal-like cells while acquiring cancer stem cell properties and therapy resistance. As EMT is involved in such a broad range of processes associated with malignant transformation, it has become an increasingly interesting target for the development of novel therapeutic strategies. Anti-EMT therapeutic strategies could potentially not only prevent the invasion and dissemination of cancer cells, and as such prevent the formation of metastatic lesions, but also attenuate cancer stemness and increase the effectiveness of more classical chemotherapeutics. In this review, we give an overview about the pros and cons of therapies targeting EMT and discuss some already existing candidate drug targets and high-throughput screening tools to identify novel anti-EMT compounds.

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