Metastasis accounts for most of cancer-related deaths. Paracrine signaling between tumor cells and the stroma induces changes in the tumor microenvironment required for metastasis. Transcription factor c-Myb was associated with breast cancer (BC) progression but its role in metastasis remains unclear. Here we show that increased c-Myb expression in BC cells inhibits spontaneous lung metastasis through impaired tumor cell extravasation. On contrary, BC cells with increased lung metastatic capacity exhibited low c-Myb levels. We identified a specific inflammatory signature, including Ccl2 chemokine, that was expressed in lung metastatic cells but was suppressed in tumor cells with higher c-Myb levels. Tumor cell-derived Ccl2 expression facilitated lung metastasis and rescued trans-endothelial migration of c-Myb overexpressing cells. Clinical data show that the identified inflammatory signature, together with a MYB expression, predicts lung metastasis relapse in BC patients. These results demonstrate that the c-Myb-regulated transcriptional program in BCs results in a blunted inflammatory response and consequently suppresses lung metastasis.
- MeSH
- apoptóza MeSH
- chemokin CCL2 genetika metabolismus MeSH
- lidé MeSH
- lokální recidiva nádoru genetika metabolismus patologie MeSH
- myši inbrední BALB C MeSH
- myši inbrední C57BL MeSH
- myši inbrední NOD MeSH
- myši SCID MeSH
- myši MeSH
- nádorové biomarkery genetika metabolismus MeSH
- nádorové buňky kultivované MeSH
- nádorové mikroprostředí MeSH
- nádory plic genetika metabolismus sekundární MeSH
- nádory prsu genetika metabolismus patologie MeSH
- prognóza MeSH
- proliferace buněk MeSH
- protoonkogenní proteiny c-myb genetika metabolismus MeSH
- regulace genové exprese u nádorů * MeSH
- xenogenní modely - testy antitumorózní aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- CCL2 protein, human MeSH Prohlížeč
- chemokin CCL2 MeSH
- nádorové biomarkery MeSH
- protoonkogenní proteiny c-myb MeSH
The transcription factor c-MYB is a well-known marker of undifferentiated cells such as haematopoietic cell precursors, but recently it has also been observed in differentiated cells that produce hard tissues. Our previous findings showed the presence of c-MYB in intramembranous bones and its involvement in the chondrogenic steps of endochondral ossification, where the up-regulation of early chondrogenic markers after c-myb overexpression was observed. Since we previously detected c-MYB in osteoblasts, we aimed to analyse the localisation of c-MYB during later stages of endochondral bone formation and address its function during bone matrix production. c-MYB-positive cells were found in the chondro-osseous junction zone in osteoblasts of trabecular bone as well as deeper in the zone of ossification in cells of spongy bone. To experimentally evaluate the osteogenic potential of c-MYB during endochondral bone formation, micromasses derived from embryonic mouse limb buds were established. Nuclear c-MYB protein expression was observed in long-term micromasses, especially in the areas around nodules. c-myb overexpression induced the expression of osteogenic-related genes such as Bmp2, Comp, Csf2 and Itgb1. Moreover, alizarin red staining and osteocalcin labelling promoted mineralised matrix production in c-myb-overexpressing cultures, whereas downregulation of c-myb by siRNA reduced mineralised matrix production. In conclusion, c-Myb plays a role in the osteogenesis of long bones by inducing osteogenic genes and causing the enhancement of mineral matrix production. This action of the transcription factor c-Myb might be of interest in the future for the establishment of novel approaches to tissue regeneration.
- Klíčová slova
- Micromass cultures, Mineralised matrix, Mouse limbs, Osteogenesis, PCR Array,
- MeSH
- buněčná diferenciace fyziologie MeSH
- chondrogeneze fyziologie MeSH
- kosti a kostní tkáň metabolismus MeSH
- myši MeSH
- osteoblasty cytologie metabolismus MeSH
- osteogeneze fyziologie MeSH
- osteokalcin metabolismus MeSH
- protoonkogenní proteiny c-myb genetika metabolismus MeSH
- upregulace MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- osteokalcin MeSH
- protoonkogenní proteiny c-myb MeSH
Cyanobacteria are physiologically and morphologically diverse photosynthetic microbes that play major roles in the carbon and nitrogen cycles of the biosphere. Recently, they have gained attention as potential platforms for the production of biofuels and other renewable chemicals. Many cyanobacteria were characterized morphologically prior to the advent of genome sequencing. Here, we catalog cyanobacterial ultrastructure within the context of genomic sequence information, including high-magnification transmission electron micrographs that represent the diversity in cyanobacterial morphology. We place the image data in the context of tabulated protein domains-which are the structural, functional, and evolutionary units of proteins-from the 126 cyanobacterial genomes comprising the CyanoGEBA dataset. In particular, we identify the correspondence between ultrastructure and the occurrence of genes encoding protein domains related to the formation of cyanobacterial inclusions. This compilation of images and genome-level domain occurrence will prove useful for a variety of analyses of cyanobacterial sequence data and provides a guidebook to morphological features.
- Klíčová slova
- Bioinformatics *, Carboxysome *, Cyanobacteria *, Cyanophycin *, Gas vesicles *, Glycogen *, Lipid droplets *, Morphology *, PHB *, Polyphosphate *, Protein domain *, Transmission electron microscopy *, Ultrastructure *,
- MeSH
- bakteriální proteiny klasifikace genetika metabolismus MeSH
- fylogeneze MeSH
- genom bakteriální genetika MeSH
- genomika * MeSH
- proteinové domény MeSH
- sekvenční analýza DNA MeSH
- sinice * genetika ultrastruktura MeSH
- transmisní elektronová mikroskopie MeSH
- výpočetní biologie MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- srovnávací studie MeSH
- Názvy látek
- bakteriální proteiny MeSH
Dental hard tissues are formed particularly by odontoblasts (dentin) and ameloblasts (enamel). Whereas the reparation of dentin is often observed, enamel does not regenerate in most species. However, in mouse incisor, a population of somatic stem cells in the cervical loop is responsible for the incisor regeneration. Understanding of the specificities of these cells is therefore of an interest in basic research as well as regenerative therapies. The Myb transcription factors are involved in essential cellular processes. B-Myb is often linked to the stem cell phenotype, and c-Myb expression marks undifferentiated and proliferating cells such as the stem cells. In the presented study, temporo-spatial expression of B-Myb and c-Myb proteins was correlated with localisation of putative somatic stem cells in the mouse incisor cervical loop by immunohistochemistry. B-Myb expression was localised mostly in the zone of transit-amplifying cells, and c-Myb was found in the inner enamel epithelium, the surrounding mesenchyme and in differentiated cells. Taken together, neither B-Myb nor c-Myb was exclusively present or abundant in the area of the incisor stem cell niche. Their distribution, however, supports recently reported novel functions of c-Myb in differentiation of hard tissue cells.
- MeSH
- buněčná diferenciace MeSH
- kmenové buňky cytologie MeSH
- mezoderm cytologie MeSH
- myši MeSH
- nika kmenových buněk fyziologie MeSH
- proliferace buněk MeSH
- proteiny buněčného cyklu metabolismus MeSH
- protoonkogenní proteiny c-myb metabolismus MeSH
- řezáky anatomie a histologie embryologie MeSH
- trans-aktivátory metabolismus MeSH
- vývojová regulace genové exprese MeSH
- zubní sklovina cytologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- Mybl2 protein, mouse MeSH Prohlížeč
- proteiny buněčného cyklu MeSH
- protoonkogenní proteiny c-myb MeSH
- trans-aktivátory MeSH
The Myb locus encodes the c-Myb transcription factor involved in controlling a broad variety of cellular processes. Recently, it has been shown that c-Myb may play a specific role in hard tissue formation; however, all of these results were gathered from an analysis of intramembranous ossification. To investigate a possible role of c-Myb in endochondral ossification, we carried out our study on the long bones of mouse limbs during embryonic development. Firstly, the c-myb expression pattern was analyzed by in situ hybridization during endochondral ossification of long bones. c-myb positive areas were found in proliferating as well as hypertrophic zones of the growth plate. At early embryonic stages, localized expression was also observed in the perichondrium and interdigital areas. The c-Myb protein was found in proliferating chondrocytes and in the perichondrium of the forelimb bones (E14.5-E17.5). Furthermore, protein was detected in pre-hypertrophic as well as hypertrophic chondrocytes. Gain-of-function and loss-of-function approaches were used to test the effect of altered c-myb expression on chondrogenesis in micromass cultures established from forelimb buds of mouse embryos. A loss-of-function approach using c-myb specific siRNA decreased nodule formation, as well as downregulated the level of Sox9 expression, a major marker of chondrogenesis. Transient c-myb overexpression markedly increased the formation of cartilage nodules and the production of extracellular matrix as detected by intense staining with Alcian blue. Moreover, the expression of early chondrogenic genes such as Sox9, Col2a1 and activity of a Col2-LUC reporter were increased in the cells overexpressing c-myb while late chondrogenic markers such as Col10a1 and Mmp13 were not significantly changed or were downregulated. Taken together, the results of this study demonstrate that the c-Myb transcription factor is involved in the regulation and promotion of endochondral bone formation.
- Klíčová slova
- Chondrogenesis, Endochondral bone, Micromass cultures, Mouse limbs, Up- and down-regulation, siRNA,
- MeSH
- biologické markery metabolismus MeSH
- buněčná diferenciace MeSH
- chondrogeneze fyziologie MeSH
- hybridizace in situ MeSH
- končetiny embryologie MeSH
- myši MeSH
- protoonkogenní proteiny c-myb genetika fyziologie MeSH
- umlčování genů MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
- protoonkogenní proteiny c-myb MeSH
The most dangerous aspect of cancer is the metastatic spread to other parts of the body. Cancer cells frequently use circulation to spread to secondary locations. By entering the blood-stream (in a process called intravasation) and by crossing the vessel walls at the metastatic sites (extravasation) tumor cells disseminate to distal organs and eventually form life threatening metastases. Crossing the vessel walls (transendothelial migration) is a vital step of metastatic cascade and the elucidation of mechanisms involved in transendothelial migration might inspire new strategies of targeted antimetastatic therapy. There are several methods to study transendothelial migration in living models (in vivo). Although they offer complex physiological microenvironment, they are expensive and technically demanding, therefore not widely used. As an alternative, sophisticated techniques to investigate transendothelial migration in vitro have been developed. They are generally more available and feasible, but there is still considerable variability in the difficulty of performance, the requirements for specialized devices, accuracy of in vivo simulation and relevance for oncological applications. The classification, various modifications, pros and cons of in vitro techniques for studying transendothelial migration are summarized in this review.
Apoptosis is type I programmed cell death, a process that is essential for development and tissue homeostasis. It is a prevalent form of cell death and it proceeds via two signaling pathways - external (receptor pathway) triggered by death receptors and intrinsic (mitochondrial) apoptotic pathway with major involvement of mitochondria. Mitochondria are important cellular organelles producing energy stored in molecules of adenosine triphosphate that are essential for cell survival. The mitochondrial cell death is characterized by permeabilization of the mitochondrial outer membrane and dissipation of the transmembrane potential. Mitochondria are electronegative organelles and depolarization of the mitochondrial membrane is important for the release of proapoptotic signals. Aberrant control of the mitochondrial cell death might contribute to several diseases including cancer. Mitochondria are also a source of reactive oxygen species, Ca2+ ions and other proteins that affect processes important for the initiation and progression of tumors independently of apoptosis. Current studies focus on research of mitochondrial membrane potential and reactive oxygen species modulating various signaling pathways within the cell, their importance in carcinogenesis, and in treatment of oncological patients. Monitoring of the apoptotic markers, such as the mitochondrial membrane potential (MMP), and the level of reactive oxygen species in samples of oncological patients has a predictive value for the output of treatment protocols.
- MeSH
- apoptóza * MeSH
- buněčná membrána fyziologie MeSH
- lidé MeSH
- mitochondrie fyziologie MeSH
- nádory patofyziologie MeSH
- průtoková cytometrie * MeSH
- reaktivní formy kyslíku metabolismus MeSH
- signální transdukce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- reaktivní formy kyslíku MeSH
The Myb transcription factors are involved in essential cellular processes, such as cell proliferation, differentiation and cell death. Biological functions carried out by specific Myb proteins are distinct. Hair follicles are ectodermal-derived organs with cycling character of the growth resulting from the presence of somatic stem cells. In this study, we followed the expression of the Myb proteins in developing hair follicles and in the hair follicle stem cell niche by immunofluorescence staining. During hair follicle development, B-Myb was present in a few cells located in the area of cell division; c-Myb was abundant postanally in dividing cells but also in keratinizing zone. In addition, c-Myb was also detected in cells under the hair follicle bulge. These findings indicate possible involvement of c-Myb in regulation of activated stem cells leaving the niche.
- Klíčová slova
- B-Myb, Development, Hair follicle, Stem cells, c-Myb,
- MeSH
- fluorescenční protilátková technika MeSH
- myši MeSH
- onkogenní proteiny v-myb metabolismus MeSH
- vlasový folikul embryologie růst a vývoj metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- onkogenní proteiny v-myb MeSH
Roscovitine, an inhibitor of cyclin-dependent kinases, is promising anticancer agent. Its antiproliferative and cytotoxic effects can be mediated by the p53 signaling pathway. To define the role of p53 in roscovitine-induced cell response, we prepared H1299/p53 cell lines inducibly expressing specific variants of p53 (p53wt and hotspot R175H, temperature-dependent P98A, A159V, S215G, Y220C, Y234C mutants). In the presence of roscovitine, each cell line variant behaved in specific way reflecting activity of the p53 protein. Roscovitine decreased production of the cell cycle inhibitor p21 and induced apoptosis. This effect was the most efficient in cells expressing p53wt protein with full activity. The cell expressing partially and conditionally active p53 mutants responded to roscovitine less efficiently. The cells expressing p53 mutants A159V and Y234C were very sensitive to roscovitine but their response was clearly temperature-dependent. The cells expressing P98A, S215G and Y220C p53 mutants exhibited only weak sensitivity to roscovitine and underwent apoptosis in low frequency. In principle, each td p53 mutant responded to roscovitine in distinct way. We showed clearly that the impact of roscovitine on H1299 cells depends on functional status of p53 they produce. This suggests that patients with tumors exhibiting specific p53 variants can benefit from the roscovitine therapy.
- MeSH
- antitumorózní látky farmakologie MeSH
- apoptóza účinky léků MeSH
- inhibitor p21 cyklin-dependentní kinasy analýza MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorový supresorový protein p53 fyziologie MeSH
- nádory plic farmakoterapie patologie MeSH
- nemalobuněčný karcinom plic farmakoterapie patologie MeSH
- puriny farmakologie MeSH
- roskovitin MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antitumorózní látky MeSH
- CDKN1A protein, human MeSH Prohlížeč
- inhibitor p21 cyklin-dependentní kinasy MeSH
- nádorový supresorový protein p53 MeSH
- puriny MeSH
- roskovitin MeSH
- TP53 protein, human MeSH Prohlížeč
The c-myb protooncogene as well as its transforming derivate, the v-myb oncogene code for transcription factors. They regulate transcription of specific target genes thus controlling proliferation, differentiation and apoptosis of hematopoietic cells. Up-regulation of the c-myb expression or rearrangement/amplification of the myb locus are often involved in leukemogenesis. Enforced myb expression blocks differentiation of various leukemic cell lines. Human promonocytes U937 can be induced to differentiate to monocyte/macrophage-like cells using phorbol esters or to granulocytes using retinoic acid. In order to investigate transforming capability of v-myb, we expressed the v-myb oncogene of avian myeloblastosis virus in U937 cells. We found that v-Myb efficiently suppressed formation of macrophages upon treatment with phorbol ester. Some features of granulocytic differentiation of retinoic acid-treated U937 cells were affected by the v-Myb protein as well. These results document that v-Myb is significantly involved in control of myeloid differentiation.
- MeSH
- buněčná diferenciace účinky léků MeSH
- exprese genu MeSH
- forbolové estery farmakologie MeSH
- geny myb * MeSH
- granulocyty účinky léků MeSH
- lidé MeSH
- makrofágy účinky léků MeSH
- monocyty účinky léků MeSH
- transfekce MeSH
- tretinoin farmakologie MeSH
- U937 buňky MeSH
- virová transformace buněk MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- forbolové estery MeSH
- tretinoin MeSH
