scholarly journals MicroRNAs and Stem-like Properties: The Complex Regulation Underlying Stemness Maintenance and Cancer Development

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1074
Author(s):  
Giuseppina Divisato ◽  
Silvia Piscitelli ◽  
Mariantonietta Elia ◽  
Emanuela Cascone ◽  
Silvia Parisi
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Embryonic Stem ◽  
Cell Types ◽  
Cancer Development ◽  
Special Focus ◽  
Self Renewal ◽  
Mesenchymal Transition ◽  
Different Cell Types

Embryonic stem cells (ESCs) have the extraordinary properties to indefinitely proliferate and self-renew in culture to produce different cell progeny through differentiation. This latter process recapitulates embryonic development and requires rounds of the epithelial–mesenchymal transition (EMT). EMT is characterized by the loss of the epithelial features and the acquisition of the typical phenotype of the mesenchymal cells. In pathological conditions, EMT can confer stemness or stem-like phenotypes, playing a role in the tumorigenic process. Cancer stem cells (CSCs) represent a subpopulation, found in the tumor tissues, with stem-like properties such as uncontrolled proliferation, self-renewal, and ability to differentiate into different cell types. ESCs and CSCs share numerous features (pluripotency, self-renewal, expression of stemness genes, and acquisition of epithelial–mesenchymal features), and most of them are under the control of microRNAs (miRNAs). These small molecules have relevant roles during both embryogenesis and cancer development. The aim of this review was to recapitulate molecular mechanisms shared by ESCs and CSCs, with a special focus on the recently identified classes of microRNAs (noncanonical miRNAs, mirtrons, isomiRs, and competitive endogenous miRNAs) and their complex functions during embryogenesis and cancer development.

scholarly journals HERV-K HML-2 transcription in diverse cancers is related with cancer stem cell and epithelial-mesenchymal transition markers

2018 ◽  
Author(s):  
Audrey T. Lin ◽  
Cindy G. Santander ◽  
Fabricia F. Nascimento ◽  
Emanuele Marchi ◽  
Timokratis Karamitros ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cancer Stem Cell ◽  
Human Genome ◽  
Cancer Metastasis ◽  
Epithelial Mesenchymal Transition ◽  
Embryonic Stem ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Mesenchymal Transition

AbstractEndogenous retroviruses (ERVs) are remnants of ancient retroviral infections that make up 8% of the human genome. Although these elements are mostly fragmented and inactive, many proviruses belonging to the HERV-K (HML-2) family, the youngest lineage in the human genome, have intact open reading frames, some encoding for accessory genes called np9 and rec that interact with oncogenic pathways. Many studies have established that ERVs are transiently expressed in both stem cells and cancer, resulting in aberrant self-renewal and uncontrolled proliferation. np9 and rec expression are significantly correlated with a range of cancer stem cell (CSC) and epithelial to mesenchymal transition (EMT) biomarkers, including cellular receptors, transcription factors, and histone modifiers. Surprisingly, these ERV genes are negatively correlated with genes known to promote pluripotency in embryonic stem cell lines, such as Oct4. These results indicate that HERV-K (HML-2) is part of the transcriptional landscape responsible for cancer cells undergoing the phenotypic switch that characterises EMT. The discovery of np9 and rec’s correlation with CSC and EMT biomarkers suggest a yet undescribed role affecting the transitional CSC-like state in EMT and the shift towards cancer malignancy.ImportanceIn this study, we find that human endogenous retrovirus HERV-K (HML-2)-encoded genes np9 and rec are correlated with the expression of many biomarkers associated with cancer stem cells (CSC) and epithelial-mesenchymal transition (EMT). There has been a significant effort to develop novel treatments targeting CSC and EMT-specific signalling pathways and cell surface markers. This research describes HERV-K (HML-2) as interacting or being part of the regulatory network that make up reversible cell state switching in EMT. Our findings suggest these specific HERVs may be good candidate biomarkers in identifying the transitional CSC-like states that are present during the progression of EMT and cancer metastasis.

Investigation of the Stem Cells Used in Modeling Human Placental Trophoblast

2021 ◽  
Author(s):  
Lulu Ji ◽  
Lin Wang
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Embryonic Stem ◽  
Cell Lineage ◽  
Cell Types ◽  
Model Systems ◽  
Alternative Methods ◽  
Laboratory Animals ◽  
Placental Development ◽  
Induced Pluripotent

Human placenta is vital for fetal development, and act as an interface between the fetus and the expecting mother. Abnormal placentati on underpins various pregnancy complications such as miscarriage, pre-eclampsia and intrauterine growth restriction. Despite the important role of placenta, the molecular mechanisms governing placental formation and trophoblast cell lineage specification is poorly understand. It is mostly due to the lack of appropriate model system. The great various in placental types across mammals make it limit for the use of laboratory animals in studying human placental development. However, over the past few years, alternative methods have been employed, including human embryonic stem cells, induced pluripotent stem cells, human trophoblast stem cell, and 3-dimensional organoids. Herein, we summarize the present knowledge about human development, differentiated cell types in the trophoblast epithelium and current human placental trophoblast model systems.

scholarly journals Counteracting Chemoresistance with Metformin in Breast Cancers: Targeting Cancer Stem Cells

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2482
Author(s):  
Samson Mathews Samuel ◽  
Elizabeth Varghese ◽  
Lenka Koklesová ◽  
Alena Líšková ◽  
Peter Kubatka ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Cancer Stem Cells ◽  
Molecular Mechanisms ◽  
Epithelial Mesenchymal Transition ◽  
Acquired Resistance ◽  
Breast Cancers ◽  
Intrinsic Resistance ◽  
Mesenchymal Transition ◽  
Cancer Breast

Despite the leaps and bounds in achieving success in the management and treatment of breast cancers through surgery, chemotherapy, and radiotherapy, breast cancer remains the most frequently occurring cancer in women and the most common cause of cancer-related deaths among women. Systemic therapeutic approaches, such as chemotherapy, although beneficial in treating and curing breast cancer subjects with localized breast tumors, tend to fail in metastatic cases of the disease due to (a) an acquired resistance to the chemotherapeutic drug and (b) the development of intrinsic resistance to therapy. The existence of cancer stem cells (CSCs) plays a crucial role in both acquired and intrinsic chemoresistance. CSCs are less abundant than terminally differentiated cancer cells and confer chemoresistance through a unique altered metabolism and capability to evade the immune response system. Furthermore, CSCs possess active DNA repair systems, transporters that support multidrug resistance (MDR), advanced detoxification processes, and the ability to self-renew and differentiate into tumor progenitor cells, thereby supporting cancer invasion, metastasis, and recurrence/relapse. Hence, current research is focusing on targeting CSCs to overcome resistance and improve the efficacy of the treatment and management of breast cancer. Studies revealed that metformin (1, 1-dimethylbiguanide), a widely used anti-hyperglycemic agent, sensitizes tumor response to various chemotherapeutic drugs. Metformin selectively targets CSCs and improves the hypoxic microenvironment, suppresses the tumor metastasis and inflammation, as well as regulates the metabolic programming, induces apoptosis, and reverses epithelial–mesenchymal transition and MDR. Here, we discuss cancer (breast cancer) and chemoresistance, the molecular mechanisms of chemoresistance in breast cancers, and metformin as a chemo-sensitizing/re-sensitizing agent, with a particular focus on breast CSCs as a critical contributing factor to acquired and intrinsic chemoresistance. The review outlines the prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer/chemo-sensitizing drug in the treatment of breast cancer. It intends to provide a rationale for the use of metformin as a combinatory therapy in a clinical setting.

scholarly journals Role of the epithelial–mesenchymal transition and its effects on embryonic stem cells

2014 ◽  
Vol 46 (8) ◽  
pp. e108-e108 ◽  
Author(s):  
Ye-Seul Kim ◽  
Bo-Rim Yi ◽  
Nam-Hyung Kim ◽  
Kyung-Chul Choi
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Epithelial Mesenchymal Transition ◽  
Embryonic Stem ◽  
Mesenchymal Transition

Tyrosine kinase signalling in embryonic stem cells

2008 ◽  
Vol 115 (2) ◽  
pp. 43-55 ◽  
Author(s):  
Cecilia Annerén
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
Self Renewal ◽  
Mouse Es Cells ◽  
Wide Range

Pluripotent ES (embryonic stem) cells can be expanded in culture and induced to differentiate into a wide range of cell types. Self-renewal of ES cells involves proliferation with concomitant suppression of differentiation. Some critical and conserved pathways regulating self-renewal in both human and mouse ES cells have been identified, but there is also evidence suggesting significant species differences. Cytoplasmic and receptor tyrosine kinases play important roles in proliferation, survival, self-renewal and differentiation in stem, progenitor and adult cells. The present review focuses on the role of tyrosine kinase signalling for maintenance of the undifferentiated state, proliferation, survival and early differentiation of ES cells.

scholarly journals Loss of Function of E-Cadherin in Embryonic Stem Cells and the Relevance to Models of Tumorigenesis

2011 ◽  
Vol 2011 ◽  
pp. 1-19 ◽  
Author(s):  
Lisa Mohamet ◽  
Kate Hawkins ◽  
Christopher M. Ward
Keyword(s):  
Stem Cells ◽  
Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Es Cells ◽  
Embryonic Stem ◽  
Loss Of Function ◽  
Mesenchymal Transition ◽  
Cell Metastasis ◽  
Patient Prognosis ◽  
E Cadherin

E-cadherin is the primary cell adhesion molecule within the epithelium, and loss of this protein is associated with a more aggressive tumour phenotype and poorer patient prognosis in many cancers. Loss of E-cadherin is a defining characteristic of epithelial-mesenchymal transition (EMT), a process associated with tumour cell metastasis. We have previously demonstrated an EMT event during embryonic stem (ES) cell differentiation, and that loss of E-cadherin in these cells results in altered growth factor response and changes in cell surface localisation of promigratory molecules. We discuss the implication of loss of E-cadherin in ES cells within the context of cancer stem cells and current models of tumorigenesis. We propose that aberrant E-cadherin expression is a critical contributing factor to neoplasia and the early stages of tumorigenesis in the absence of EMT by altering growth factor response of the cells, resulting in increased proliferation, decreased apoptosis, and acquisition of a stem cell-like phenotype.

scholarly journals Repression of Nanog Gene Transcription by Tcf3 Limits Embryonic Stem Cell Self-Renewal

2006 ◽  
Vol 26 (20) ◽  
pp. 7479-7491 ◽  
Author(s):  
Laura Pereira ◽  
Fei Yi ◽  
Bradley J. Merrill
Keyword(s):  
Stem Cells ◽  
Transcription Factors ◽  
Molecular Mechanisms ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Regulatory Region ◽  
Embryonic Stem ◽  
Dual Function ◽  
Self Renewal ◽  
Nanog Gene

ABSTRACT The dual function of stem cells requires them not only to form new stem cells through self-renewal but also to form lineage-committed cells through differentiation. Embryonic stem cells (ESC), which are derived from the blastocyst inner cell mass, retain properties of self-renewal and the potential for lineage commitment. To balance self-renewal and differentiation, ESC must carefully control the levels of several transcription factors, including Nanog, Sox2, and Oct4. While molecular mechanisms promoting transcription of these genes have been described, mechanisms preventing excessive levels in self-renewing ESC remain unknown. By examining the function of the TCF family of transcription factors in ESC, we have found that Tcf3 is necessary to limit the steady-state levels of Nanog mRNA, protein, and promoter activity in self-renewing ESC. Chromatin immunoprecipitation and promoter reporter assays showed that Tcf3 bound to a promoter regulatory region of the Nanog gene and repressed its transcriptional activity in ESC through a Groucho interaction domain-dependent process. The absence of Tcf3 caused delayed differentiation of ESC in vitro as elevated Nanog levels persisted through 5 days of embryoid body formation. These new data support a model wherein Tcf3-mediated control of Nanog levels allows stem cells to balance the creation of lineage-committed and undifferentiated cells.

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