Embryonic stem cells and induced pluripotent stem cells provided us with fascinating new knowledge in recent years. Mechanistic insight into intricate regulatory circuitry governing pluripotency stemness and disclosing parallels between pluripotency stemness and cancer instigated numerous studies focusing on roles of pluripotency transcription factors, including Oct4, Sox2, Klf4, Nanog, Sall4 and Tfcp2L1, in cancer. Although generally well substantiated as tumour-promoting factors, oncogenic roles of pluripotency transcription factors and their clinical impacts are revealing themselves as increasingly complex. In certain tumours, both Oct4 and Sox2 behave as genuine oncogenes, and reporter genes driven by composite regulatory elements jointly recognized by both the factors can identify stem-like cells in a proportion of tumours. On the other hand, cancer stem cells seem to be biologically very heterogeneous both among different tumour types and among and even within individual tumours. Pluripotency transcription factors are certainly implicated in cancer stemness, but do not seem to encompass its entire spectrum. Certain cancer stem cells maintain their stemness by biological mechanisms completely different from pluripotency stemness, sometimes even by engaging signalling pathways that promote differentiation of pluripotent stem cells. Moreover, while these signalling pathways may well be antithetical to stemness in pluripotent stem cells, they may cooperate with pluripotency factors in cancer stem cells - a paradigmatic example is provided by the MAPK-AP-1 pathway. Unexpectedly, forced expression of pluripotency transcription factors in cancer cells frequently results in loss of their tumour-initiating ability, their phenotypic reversion and partial epigenetic normalization. Besides the very different signalling contexts operating in pluripotent and cancer stem cells, respectively, the pronounced dose dependency of reprogramming pluripotency factors may also contribute to the frequent loss of tumorigenicity observed in induced pluripotent cancer cells. Finally, contradictory cell-autonomous and non-cell-autonomous effects of various signalling molecules operate during pluripotency (cancer) reprogramming. The effects of pluripotency transcription factors in cancer are thus best explained within the concept of cancer stem cell heterogeneity.

• MeSH
• buněčná diferenciace genetika   MeSH
• embryonální kmenové buňky MeSH
• indukované pluripotentní kmenové buňky * metabolismus   MeSH
• lidé MeSH
• nádory * genetika   metabolismus   MeSH
• oktamerní transkripční faktor 3 genetika   metabolismus   MeSH
• pluripotentní kmenové buňky * MeSH
• přeprogramování buněk genetika   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Objev indukované pluripotence v roce 2006 umožnil revoluční způsob získávaní autologních terapeuticky aplikovatelných buněk, a mož‐ nost modelovat jakékoliv onemocnění v in vitro podmínkách. Možnost vrátit libovolnou, finálně diferencovanou buňku „v čase“ zpátky do stádia pluripotence je zajímavé i pro oblast onkologického výzkumu. Tato technologie umožnila studium procesů spojených s roz‐ vojem nádorového fenotypu buňky a taky s přechodem nádorové buňky do stádia s nižší mírou diferenciace. Reprogramování buněk do indukovaných pluripotentních kmenových buněk také pomáhá mnohem lépe studovat raritní populaci buněk, přítomných v nádo‐ rech – tzv. nádorové kmenové buňky. Indukovaná pluripotence některých typů nádorových buněk, spojená s jejich následnou řízenou diferenciací by se zároveň mohla stát jednou z možných terapeutických aplikací v onkologii.

Discovery of technology of induced pluripotency that allows the generation of autologous therapeutically applicable cells and generati‐ on of in vitro cell models for diseases with limited (or highly invasive) access to tested cells has also opened new horizons in the field of oncology research. The unique ability to reprogram the cancer cell into pluripotency with subsequent directed differentiation into cell with no malignant phenotype should be considered as a challenge in the field of new oncotherapy development. Although still conside‐ red to be realistic only on the level of experimental approach, the recent progress in the field of induced pluripotency gives the hope that dedifferentiation‐based therapies connected with the erase of malignant phenotype of original cancer cell will be more realistic in near future. By then, the most important role of induced pluripotency in oncology remains in the field of regenerative therapy as a source of autologous cells for regeneration of tissues or organs damaged by tumor growth or aggressive therapy

• MeSH
• lidé MeSH
• nádorové kmenové buňky MeSH
• nádory terapie   MeSH
• přeprogramování buněk MeSH
• techniky buněčného přeprogramování * metody   MeSH
• Check Tag
• lidé MeSH

The foundations of cell reprogramming were laid by Yamanaka and co-workers, who showed that somatic cells can be reprogrammed into pluripotent cells (induced pluripotency). Since this discovery, the field of regenerative medicine has seen advancements. For example, because they can differentiate into multiple cell types, pluripotent stem cells are considered vital components in regenerative medicine aimed at the functional restoration of damaged tissue. Despite years of research, both replacement and restoration of failed organs/ tissues have remained elusive scientific feats. However, with the inception of cell engineering and nuclear reprogramming, useful solutions have been identified to counter the need for compatible and sustainable organs. By combining the science underlying genetic engineering and nuclear reprogramming with regenerative medicine, scientists have engineered cells to make gene and stem cell therapies applicable and effective. These approaches have enabled the targeting of various pathways to reprogramme cells, i.e., make them behave in beneficial ways in a patient-specific manner. Technological advancements have clearly supported the concept and realization of regenerative medicine. Genetic engineering is used for tissue engineering and nuclear reprogramming and has led to advances in regenerative medicine. Targeted therapies and replacement of traumatized , damaged, or aged organs can be realized through genetic engineering. Furthermore, the success of these therapies has been validated through thousands of clinical trials. Scientists are currently evaluating induced tissue-specific stem cells (iTSCs), which may lead to tumour-free applications of pluripotency induction. In this review, we present state-of-the-art genetic engineering that has been used in regenerative medicine. We also focus on ways that genetic engineering and nuclear reprogramming have transformed regenerative medicine and have become unique therapeutic niches.

• MeSH
• genetické inženýrství MeSH
• indukované pluripotentní kmenové buňky metabolismus   cytologie   MeSH
• lidé MeSH
• přeprogramování buněk * MeSH
• regenerativní lékařství * MeSH
• tkáňové inženýrství MeSH
• vývojová biologie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

MicroRNA (miRNAs) are short noncoding RNA molecules involved in many cellular processes and shown to play a key role in somatic cell induced reprogramming. We performed an array based screening to identify candidates that are differentially expressed between dermal skin fibroblasts (DFs) and induced pluripotent stem cells (iPSCs). We focused our investigations on miR-145 and showed that this candidate is highly expressed in DFs relative to iPSCs and significantly downregulated during reprogramming process. Inhibition of miR-145 in DFs led to the induction of "cellular plasticity" demonstrated by: (a) alteration of cell morphology associated with downregulation of mesenchymal and upregulation of epithelial markers; (b) upregulation of pluripotency-associated genes including SOX2, KLF4, C-MYC; (c) downregulation of miRNA let-7b known to inhibit reprogramming; and (iv) increased efficiency of reprogramming to iPSCs in the presence of reprogramming factors. Together, our results indicate a direct functional link between miR-145 and molecular pathways underlying reprogramming of somatic cells to iPSCs.

• MeSH
• fibroblasty cytologie   metabolismus   MeSH
• indukované pluripotentní kmenové buňky cytologie   MeSH
• lidé MeSH
• mikro RNA genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• přeprogramování buněk * genetika   MeSH
• regulace genové exprese MeSH
• reprodukovatelnost výsledků MeSH
• sekvence nukleotidů MeSH
• škára cytologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Aim: Human induced pluripotent stem cells (iPSCs) are inefficiently derived from somatic cells by overexpression of defined transcription factors. Overexpression of H2A histone variant macroH2A1.1, but not macroH2A1.2, leads to increased iPSC reprogramming by unclear mechanisms. Materials & methods: Cleavage under targets and tagmentation (CUT&Tag) allows robust epigenomic profiling of a low cell number. We performed an integrative CUT&Tag-RNA-Seq analysis of macroH2A1-dependent orchestration of iPSCs reprogramming using human endothelial cells. Results: We demonstrate wider genome occupancy, predicted transcription factors binding, and gene expression regulated by macroH2A1.1 during reprogramming, compared to macroH2A1.2. MacroH2A1.1, previously associated with neurodegenerative pathologies, specifically activated ectoderm/neural processes. Conclusion: CUT&Tag and RNA-Seq data integration is a powerful tool to investigate the epigenetic mechanisms occurring during cell reprogramming.

• MeSH
• endoteliální buňky metabolismus   MeSH
• histony * metabolismus   MeSH
• indukované pluripotentní kmenové buňky * metabolismus   MeSH
• lidé MeSH
• přeprogramování buněk genetika   MeSH
• sekvenování transkriptomu MeSH
• transkripční faktory genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

RNA silencing is a complex of mechanisms that regulate gene expression through small RNA molecules. The microRNA (miRNA) pathway is the most common of these in mammals. Genome-encoded miRNAs suppress translation in a sequence-specific manner and facilitate shifts in gene expression during developmental transitions. Here, we discuss the role of miRNAs in oocyte-to-zygote transition and in the control of pluripotency. Existing data suggest a common principle involving miRNAs in defining pluripotent and differentiated cells. RNA silencing pathways also rapidly evolve, resulting in many unique features of RNA silencing in different taxonomic groups. This is exemplified in the mouse model of oocyte-to-zygote transition, in which the endogenous RNA interference pathway has acquired a novel role in regulating protein-coding genes, while the miRNA pathway has become transiently suppressed.

• MeSH
• fylogeneze MeSH
• lidé MeSH
• malá interferující RNA genetika   metabolismus   MeSH
• mikro RNA klasifikace   genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• oocyty cytologie   fyziologie   MeSH
• pluripotentní kmenové buňky cytologie   fyziologie   MeSH
• RNA interference MeSH
• sekvence nukleotidů MeSH
• sekvenční seřazení MeSH
• zvířata MeSH
• zygota cytologie   fyziologie   MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

The possibility of replacing the originally discovered and widely used DNA reprogramming transcription factors is stimulating enormous effort to identify more effective compounds that would not alter the genetic information. Here, we describe the generation of induced pluripotent stem cells (iPSc) from head-derived primary culture of mouse embryonic cells using small chemical inhibitors of the MEK and TGF-beta pathways without delivery of exogenous transcription factors. These iPSc express standard pluripotency markers and retain their potential to differentiate into cells of all germ layers. Our data indicate that head-derived embryonic neural cells might have the reprogramming potential while neither the same primary cells cultivated over five passages in vitro nor a cell population derived from adult brain possesses this capacity. Our results reveal the potential for small molecules to functionally replace routinely used transcription factors and lift the veil on molecular regulation controlling pluripotency. The conditions described here could provide a platform upon which other genome non integrative and safer reprogramming processes could be developed. This work also shows novel potential for developing embryonic neural cells.

• MeSH
• diferenciační antigeny biosyntéza   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• MAP kinasový signální systém * MeSH
• myši MeSH
• přeprogramování buněk * MeSH
• transformující růstový faktor beta metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this study was to extensively characterise natal dental pulp stem cells (nDPSC) and assess their efficiency to generate human induced pluripotent stem cells (hiPSC). A number of distinguishing features prompted us to choose nDPSC over normal adult DPSC, in that they differed in cell surface marker expression and initial doubling time. In addition, nDPSC expressed 17 out of 52 pluripotency genes we analysed, and the level of expression was comparable to human embryonic stem cells (hESC). Ours is the first group to report comprehensive characterization of nDPSC followed by directed reprogramming to a pluripotent stem cell state. nDPSC yielded hiPSC colonies upon transduction with Sendai virus expressing the pluripotency transcription factors POU5F1, SOX2, c-MYC and KLF4. nDPSC had higher reprogramming efficiency compared to human fibroblasts. nDPSC derived hiPSCs closely resembled hESC in terms of their morphology, expression of pluripotency markers and gene expression profiles. Furthermore, nDPSC derived hiPSCs differentiated into the three germ layers when cultured as embryoid bodies (EB) and by directed differentiation. Based on our findings, nDPSC present a unique marker expression profile compared with adult DPSC and possess higher reprogramming efficiency as compared with dermal fibroblasts thus proving to be more amenable for reprogramming.

• MeSH
• biologické markery MeSH
• buněčná diferenciace genetika   MeSH
• embryoidní tělíska cytologie   MeSH
• fibroblasty cytologie   metabolismus   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• karyotyp MeSH
• kmenové buňky cytologie   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• předmléčné zuby cytologie   MeSH
• přeprogramování buněk * MeSH
• transkriptom MeSH
• vývojová regulace genové exprese MeSH
• zubní dřeň cytologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The potential clinical applications of human induced pluripotent stem cells (hiPSCs) are limited by genetic and epigenetic variations among hiPSC lines and the question of their equivalency with human embryonic stem cells (hESCs). We used MethylScreen technology to determine the DNA methylation profile of pluripotency and differentiation markers in hiPSC lines from different source cell types compared to hESCs and hiPSC source cells. After derivation, hiPSC lines compromised a heterogeneous population characterized by variable levels of aberrant DNA methylation. These aberrations were induced during somatic cell reprogramming and their levels were associated with the type of hiPSC source cells. hiPSC population heterogeneity was reduced during prolonged culture and hiPSCs acquired an hESC-like methylation profile. In contrast, the expression of differentiation marker genes in hiPSC lines remained distinguishable from that in hESCs. Taken together, in vitro culture facilitates hiPSC acquisition of hESC epigenetic characteristics. However, differences remain between both pluripotent stem cell types, which must be considered before their use in downstream applications.

• MeSH
• buněčná diferenciace genetika   MeSH
• buněčné linie MeSH
• fibroblasty cytologie   metabolismus   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• lidské embryonální kmenové buňky cytologie   metabolismus   MeSH
• metylace DNA * MeSH
• přeprogramování buněk genetika   MeSH
• shluková analýza MeSH
• stanovení celkové genové exprese MeSH
• vývojová regulace genové exprese MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Human induced pluripotent stem cells (hiPSCs) play roles in both disease modelling and regenerative medicine. It is critical that the genomic integrity of the cells remains intact and that the DNA repair systems are fully functional. In this article, we focused on the detection of DNA double-strand breaks (DSBs) by phosphorylated histone H2AX (known as γH2AX) and p53-binding protein 1 (53BP1) in three distinct lines of hiPSCs, their source cells, and one line of human embryonic stem cells (hESCs). METHODS: We measured spontaneously occurring DSBs throughout the process of fibroblast reprogramming and during long-term in vitro culturing. To assess the variations in the functionality of the DNA repair system among the samples, the number of DSBs induced by γ-irradiation and the decrease over time was analysed. The foci number was detected by fluorescence microscopy separately for the G1 and S/G2 cell cycle phases. RESULTS: We demonstrated that fibroblasts contained a low number of non-replication-related DSBs, while this number increased after reprogramming into hiPSCs and then decreased again after long-term in vitro passaging. The artificial induction of DSBs revealed that the repair mechanisms function well in the source cells and hiPSCs at low passages, but fail to recognize a substantial proportion of DSBs at high passages. CONCLUSIONS: Our observations suggest that cellular reprogramming increases the DSB number but that the repair mechanism functions well. However, after prolonged in vitro culturing of hiPSCs, the repair capacity decreases.

• MeSH
• 53BP1 genetika   metabolismus   MeSH
• buněčné linie MeSH
• DNA genetika   metabolismus   MeSH
• dvouřetězcové zlomy DNA * účinky záření   MeSH
• exprese genu MeSH
• fibroblasty cytologie   metabolismus   účinky záření   MeSH
• fosforylace účinky záření   MeSH
• histony genetika   metabolismus   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   účinky záření   MeSH
• kontrolní body fáze G1 buněčného cyklu genetika   MeSH
• kontrolní body fáze G2 buněčného cyklu genetika   MeSH
• lidé MeSH
• lidské embryonální kmenové buňky cytologie   metabolismus   účinky záření   MeSH
• oprava DNA genetika   MeSH
• přeprogramování buněk MeSH
• stárnutí buněk genetika   účinky záření   MeSH
• záření gama MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH