Myeloblastosis-associated virus 2 (MAV-2) is a highly tumorigenic simple avian retrovirus. Chickens infected in ovo with MAV-2 develop tumors in the kidneys, lungs, and liver with a short latency, less than 8 weeks. Here we report the results of molecular analyses of MAV-2-induced liver tumors that fall into three classes: hepatic hemangiosarcomas (HHSs), intrahepatic cholangiocarcinomas (ICCs), and hepatocellular carcinomas (HCCs). Comprehensive inverse PCR-based screening of 92 chicken liver tumors revealed that in ca. 86% of these tumors, MAV-2 provirus had integrated into one of four gene loci: HRAS, EGFR, MET, and RON Insertionally mutated genes correlated with tumor type: HRAS was hit in HHSs, MET in ICCs, RON mostly in ICCs, and EGFR mostly in HCCs. The provirus insertions led to the overexpression of the affected genes and, in the case of EGFR and RON, also to the truncation of exons encoding the extracellular ligand-binding domains of these transmembrane receptors. The structures of truncated EGFR and RON closely mimic the structures of oncogenic variants of these genes frequently found in human tumors (EGFRvIII and sfRON).IMPORTANCE These data describe the mechanisms of oncogenesis induced in chickens by the MAV-2 retrovirus. They also show that molecular processes converting cellular regulatory genes to cancer genes may be remarkably similar in chickens and humans. We suggest that the MAV-2 retrovirus-based model can complement experiments performed using mouse models and provide data that could translate to human medicine.

• Klíčová slova
• avian retroviruses, insertional mutagenesis, retroviral oncogenesis,
• MeSH
• cholangiokarcinom genetika   virologie   MeSH
• geny erbB-1 * MeSH
• hemangiosarkom genetika   virologie   MeSH
• hepatocelulární karcinom genetika   virologie   MeSH
• integrace viru MeSH
• inzerční mutageneze * MeSH
• karcinogeneze * MeSH
• kur domácí genetika   MeSH
• lidé MeSH
• nádory jater genetika   virologie   MeSH
• onkogeny MeSH
• protoonkogenní proteiny c-met genetika   MeSH
• proviry genetika   fyziologie   MeSH
• ptačí proteiny genetika   MeSH
• tyrosinkinasové receptory genetika   MeSH
• virus ptačí myeloblastózy genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protoonkogenní proteiny c-met MeSH
• ptačí proteiny MeSH
• RON protein MeSH Prohlížeč
• tyrosinkinasové receptory MeSH

The neural crest (NC) is a transient dynamic structure of ectodermal origin, found in early vertebrate embryos. The multipotential NC cells migrate along well defined routes, differentiate to various cell types including melanocytes and participate in the formation of various permanent tissues. As there is only limited information about the molecular mechanisms controlling early events in melanocyte specification and development, we exploited the AMV v-Myb transcriptional regulator, which directs differentiation of in vitro chicken NC cells to the melanocyte lineage. This activity is strictly dependent on v-Myb specifically binding to the Myb recognition DNA element (MRE). The two tamoxifen-inducible v-Myb alleles were constructed one which recognizes the MRE and one which does not. These were activated in ex ovo NC cells, and the expression profiles of resulting cells were analyzed using Affymetrix microarrays and RT-PCR. These approaches revealed up-regulation of the BMP antagonist Gremlin 2 mRNA, and down-regulation of mRNAs encoding several epithelial genes including KRT19 as very early events following the activation of melanocyte differentiation by v-Myb. The enforced v-Myb expression in neural tubes of chicken embryos resulted in detectable presence of Gremlin 2 mRNA. However, expression of Gremlin 2 in NC cells did not promote formation of melanocytes suggesting that Gremlin 2 is not the master regulator of melanocytic differentiation.

• Klíčová slova
• KRT19, Melanocyte development, PRDC, Tamoxifen-inducible v-Myb, v-Myb-dependent genes,
• MeSH
• aktivace transkripce * MeSH
• alely MeSH
• buněčná diferenciace * MeSH
• crista neuralis cytologie   MeSH
• keratin-19 genetika   metabolismus   MeSH
• kostní morfogenetický protein 5 genetika   metabolismus   MeSH
• kultivované buňky MeSH
• kuřecí embryo MeSH
• melanocyty fyziologie   MeSH
• mezibuněčné signální peptidy a proteiny genetika   metabolismus   MeSH
• onkogenní proteiny v-myb fyziologie   MeSH
• ptačí proteiny genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• transkriptom MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• keratin-19 MeSH
• kostní morfogenetický protein 5 MeSH
• mezibuněčné signální peptidy a proteiny MeSH
• onkogenní proteiny v-myb MeSH
• ptačí proteiny MeSH

Fibrotic diseases are a group of pathologies with high incidence and mortality. Despite extensive research efforts, effective therapies are still not available. Understanding the molecular mechanisms driving the onset, progression and possible resolution of fibrosis is a prerequisite to the development of successful therapies. The central role of the TGF-β pathway and myofibroblasts in the pathogenesis of fibrosis is now generally accepted. The possible mechanisms of myofibroblast elimination or dedifferentiation, on the other hand, are still almost uncharted territory. Here we show that sustained expression of some components of MAPK signaling pathway (PDGFB, Ha-Ras(G12V) or the transcription factor EGR4) in primary chicken embryo dermal myofibroblasts results in a loss of autocrine TGF-β signaling and suppression of the myofibroblastic phenotype, characterized by the loss of alpha smooth muscle actin fibers and a substantial reduction in the production of extracellular matrix. Detailed analysis of the possible molecular mechanisms employed by EGR4 revealed FOXG1, BAMBI, NAB1, NAB2 and DUSP5 genes forming an EGR4 regulated network counteracting autocrine TGF-β signaling. We have also found that a combination of chemical inhibition of TGF-β signaling and perturbation of MAPK signaling with phorbol ester mimics the anti-fibrotic effects of PDGFB, Ha-Ras(G12V) and EGR4.

• Klíčová slova
• EGR4, FOXG1, Ha-Ras(G12V), Microarrays, Myofibroblast, PDGFB, TGF-β,
• MeSH
• aktiny genetika   metabolismus   MeSH
• dediferenciace buněk * MeSH
• forbolové estery farmakologie   MeSH
• kuřecí embryo MeSH
• mitogenem aktivované proteinkinasy metabolismus   MeSH
• myofibroblasty cytologie   metabolismus   MeSH
• signální transdukce MeSH
• transformující růstový faktor beta metabolismus   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aktiny MeSH
• forbolové estery MeSH
• mitogenem aktivované proteinkinasy MeSH
• transformující růstový faktor beta MeSH

BACKGROUND: Although there is extensive evidence for the amoeboid invasiveness of cancer cells in vitro, much less is known about the role of amoeboid invasiveness in metastasis and the importance of Rho/ROCK/MLC signaling in this process. RESULTS: We analyzed the dependence of amoeboid invasiveness of rat and chicken sarcoma cells and the metastatic activity of chicken cells on individual elements of the Rho/ROCK/MLC pathway. In both animal models, inhibition of Rho, ROCK or MLC resulted in greatly decreased cell invasiveness in vitro, while inhibition of extracellular proteases using a broad spectrum inhibitor did not have a significant effect. The inhibition of both Rho activity and MLC phosphorylation by dominant negative mutants led to a decreased capability of chicken sarcoma cells to metastasize. Moreover, the overexpression of RhoA in non-metastatic chicken cells resulted in the rescue of both invasiveness and metastatic capability. Rho and ROCK, unlike MLC, appeared to be directly involved in the maintenance of the amoeboid phenotype, as their inhibition resulted in the amoeboid-mesenchymal transition in analyzed cell lines. CONCLUSION: Taken together, these results suggest that protease-independent invasion controlled by elements of the Rho/ROCK/MLC pathway can be frequently exploited by metastatic sarcoma cells.

• MeSH
• invazivní růst nádoru MeSH
• kinázy asociované s rho metabolismus   MeSH
• krysa rodu Rattus MeSH
• kur domácí MeSH
• lehké řetězce myosinu metabolismus   MeSH
• nádorové buněčné linie MeSH
• pohyb buněk MeSH
• rho proteiny vázající GTP metabolismus   MeSH
• sarkom metabolismus   patologie   MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kinázy asociované s rho MeSH
• lehké řetězce myosinu MeSH
• rho proteiny vázající GTP MeSH

The myofibroblast is a mesenchymal cell characterized by synthesis of the extracellular matrix, plus contractile and secretory activities. Myofibroblasts participate in physiological tissue repair, but can also cause devastating fibrosis. They are present in the tumor stroma of carcinomas and contribute to tumor growth and spreading. As myofibroblasts derive from various cell types and appear in a variety of tissues, there is marked variability in their phenotype. As regulatory mechanisms of wound healing are likely conserved among vertebrates, detailed knowledge of these mechanisms in more distant species will help to distinguish general from specific phenomena. To provide this as yet missing comparison, we analyzed the impact of the chemical inhibition of TGF-beta signaling on gene expression in chicken embryo dermal myofibroblasts. We revealed genes previously reported in mammalian systems (e.g. SPON2, ASPN, COMP, LUM, HAS2, IL6, CXCL12, VEGFA) as well as novel TGF-beta dependent genes, among them PGF, VEGFC, PTN, FAM180A, FIBIN, ZIC1, ADCY2, RET, HHIP and DNER. Inhibition of TGF-beta signaling also induced multiple genes, including NPR3, AGTR2, MTUS1, SOD3 and NOV. We also analyzed the effects of long term inhibition, and found that it is not able to induce myofibroblast dedifferentiation.

• MeSH
• kultivované buňky MeSH
• kur domácí genetika   MeSH
• kuřecí embryo MeSH
• myofibroblasty účinky léků   fyziologie   MeSH
• protein-serin-threoninkinasy antagonisté a inhibitory   MeSH
• receptory transformujícího růstového faktoru beta antagonisté a inhibitory   MeSH
• signální transdukce účinky léků   MeSH
• škára účinky léků   embryologie   MeSH
• TGF-beta receptor II. typu MeSH
• transformující růstový faktor beta antagonisté a inhibitory   metabolismus   MeSH
• vývojová regulace genové exprese * MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protein-serin-threoninkinasy MeSH
• receptory transformujícího růstového faktoru beta MeSH
• TGF-beta receptor II. typu MeSH
• transformující růstový faktor beta MeSH

Metastatic spreading of cancer cells is a highly complex process directed primarily by the interplay between tumor microenvironment, cell surface receptors, and actin cytoskeleton dynamics. To advance our understanding of metastatic cancer dissemination, we have developed a model system that is based on two v-src transformed chicken sarcoma cell lines-the highly metastatic parental PR9692 and a non-metastasizing but fully tumorigenic clonal derivative PR9692-E9. Oligonucleotide microarray analysis of both cell lines revealed that the gene encoding the transcription factor EGR1 was downregulated in the non-metastatic PR9692-E9 cells. Further investigation demonstrated that the introduction of exogenous EGR1 into PR9692-E9 cells restored their metastatic potential to a level indistinguishable from parental PR9692 cells. Microarray analysis of EGR1 reconstituted cells revealed the activation of genes that are crucial for actin cytoskeleton contractility (MYL9), filopodia formation (MYO10), the production of specific extracellular matrix components (HAS2, COL6A1-3) and other essential pro-metastatic abilities.

• MeSH
• buněčná adheze MeSH
• buněčné linie MeSH
• cytoskelet metabolismus   MeSH
• fenotyp MeSH
• kinetika MeSH
• kur domácí MeSH
• metastázy nádorů genetika   MeSH
• nádorová transformace buněk genetika   patologie   MeSH
• onkogenní protein pp60(v-src) genetika   metabolismus   MeSH
• pohyb buněk MeSH
• proliferace buněk MeSH
• protein 1 časné růstové odpovědi genetika   metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• sarkom genetika   patologie   MeSH
• stanovení celkové genové exprese MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• onkogenní protein pp60(v-src) MeSH
• protein 1 časné růstové odpovědi MeSH

FLT3 is the most frequently mutated gene in acute myeloid leukemia (AML), with internal tandem duplications (ITDs) accounting for up to 30% of its mutations. To analyze the impact of individual ITDs on the expression profile of immature myeloid cells, we have established 32D cell lines expressing nine different FLT3/ITDs isolated from AML patients and subjected them to whole genome expression profiling and 2DE/LC/MS proteomics. Our data indicate that in comparison to the controls, FLT3/ITD-positive 32D cells exhibit less mature expression profiles resembling early hematopoietic progenitors. Moreover, our results suggest that there exist biological differences among individual ITD variants.

• MeSH
• akutní myeloidní leukemie genetika   patologie   MeSH
• blastická krize genetika   patologie   MeSH
• buněčná diferenciace MeSH
• buněčné dělení MeSH
• exony MeSH
• genetická variace * MeSH
• klonování DNA MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• myši genetika   MeSH
• nádorové buněčné linie MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• Retroviridae genetika   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
• stanovení celkové genové exprese MeSH
• tandemové repetitivní sekvence genetika   MeSH
• tyrosinkinasa 3 podobná fms genetika   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši genetika   MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• FLT3 protein, human MeSH Prohlížeč
• tyrosinkinasa 3 podobná fms MeSH

A tumor cell is formed when a critical amount of endogenous and/or exogenous tumorigenic stimuli is exceeded. We have shown that the transient presence of nontumorigenic stray cells in tissues of experimental animals that contain cells with a subcritical set of genetic mutations can act as a tumor-promoting stimulus. To induce somatic mutations in all chicken tissues, we have used the MAV-2 retroviral insertion system that almost exclusively generates nephroblastomas. MAV-2 mutagenized animals i.v. inoculated with nonmalignant cells developed early clonal lung tumors before nephroblastomas. Importantly, the injected cells did not become a component of resultant tumors. Lung tumors displayed specific mutational signature characterized by an insertion of MAV-2 provirus into the fyn-related kinase (frk) promoter that results in the overexpression of the frk gene. In contrast, plag1, foxP, and twist genes were most often mutagenized in nephroblastomas. Based on such observations, we propose the mechanism termed industasis, a promotion of fully malignant phenotype of incipient tumor cell by stray cells, and hypothesize that it might be the underlying cause of human multiple primary tumors.

• MeSH
• biologické modely MeSH
• buňky patologie   virologie   MeSH
• fyziologie virů MeSH
• invazivní růst nádoru MeSH
• inzerční mutageneze fyziologie   MeSH
• kultivované buňky MeSH
• kur domácí MeSH
• kuřecí embryo MeSH
• mnohočetné primární nádory etiologie   MeSH
• nádorová transformace buněk patologie   MeSH
• nádory ledvin patologie   virologie   MeSH
• nádory plic patologie   virologie   MeSH
• pohyb buněk fyziologie   MeSH
• proviry růst a vývoj   fyziologie   MeSH
• Wilmsův nádor patologie   virologie   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The design and synthesis of glycol-functionalized porphyrins that contain one to four low molecular weight glycol chains that are linked via ether bonds to the meta-phenyl positions of meso-tetraphenylporphyrin and the comparison of fluorinated and nonfluorinated para derivatives are reported. The cellular uptake and photodynamic activity significantly depend on terminal groups of the glycol substituent. Hydroxy glycol porphyrins, in contrast with methoxy glycol porphyrins, show efficient intracellular transport and a high induction of apoptosis in tumor cell lines in vitro . Furthermore, the ethylene glycol chain at the meta position exhibits a superior efficacy that leads to the permanent ablation of human breast carcinoma (MDA-MB-231) in nude mice. In addition, fluorination enhanced the photosensitizing potential of para-phenyl derivatives. The analysis of the cell-death mechanism revealed that glycol-functionalized porphyrins represent novel nonmitochondrially localized photosensitizers that have a profound ability to induce apoptosis in tumor cells that act upstream of caspase activation. The strong interaction with a tumor marker (sialic acid) indicates the preferential association of these compounds with tumor cells.

• MeSH
• antitumorózní látky aplikace a dávkování   chemie   farmakologie   MeSH
• apoptóza účinky léků   MeSH
• časové faktory MeSH
• experimentální nádory farmakoterapie   MeSH
• fotochemoterapie metody   MeSH
• glykoly aplikace a dávkování   chemie   farmakologie   MeSH
• injekce intravenózní MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• molekulární struktura MeSH
• molekulová hmotnost MeSH
• myši nahé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• porfyriny aplikace a dávkování   chemie   farmakologie   MeSH
• průtoková cytometrie MeSH
• racionální návrh léčiv MeSH
• stereoizomerie MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antitumorózní látky MeSH
• glykoly MeSH
• porfyriny MeSH

OBJECTIVE: The primary objective of this study was to identify and clone the first nonmammalian thrombopoietin (TPO), chicken TPO, and its receptor c-Mpl for the purpose of characterizing their activities both in vitro and in vivo. MATERIALS AND METHODS: Chicken TPO was cloned using the methods of reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends. Northern blotting and RNAse protection assays were employed to analyze the levels of RNA expression in a panel of tissues and cell lines. To study cell surface expression of c-Mpl, polyclonal antibodies were prepared against bacterially derived c-Mpl. Both baculovirus-derived recombinant TPO and retrovirally expressed TPO and c-Mpl were used for the in vivo experiments. RESULTS: Both chicken TPO and its receptor c-Mpl were identified and cloned. Expression of chicken TPO was restricted to only the liver and spleen, while c-mpl was expressed in the bone marrow, lung, and spleen. In vitro experiments with sorted multipotent chicken bone marrow-derived progenitors demonstrated that TPO plays a role in the commitment of these cells to the thrombocytic lineage. Furthermore, TPO in cooperation with stem cell factor also supports proliferation of multipotent progenitors. In experimental animals, the intravenous application of recombinant chicken TPO or overexpression of TPO and c-mpl via retroviral infection lead to erythroblastosis and thromboblastosis. CONCLUSION: The characterized chicken thrombopoietin and its receptor c-Mpl will be valuable tools to further study thrombocytic differentiation and hematopoietic stem cell development. Moreover, the introduced experimental model of the chicken bipotent thrombo-/erythropoietic-progenitor can be used to identify key regulators of cell fate determination.

• MeSH
• buněčný rodokmen MeSH
• Escherichia coli genetika   MeSH
• fibroblasty cytologie   MeSH
• hematopoéza fyziologie   MeSH
• klonování DNA MeSH
• kur domácí MeSH
• kuřecí embryo MeSH
• lidé MeSH
• messenger RNA biosyntéza   MeSH
• molekulární sekvence - údaje MeSH
• myši MeSH
• receptory thrombopoetinu biosyntéza   genetika   fyziologie   MeSH
• rekombinantní proteiny genetika   MeSH
• sekvence aminokyselin MeSH
• sekvenční seřazení MeSH
• thrombopoetin biosyntéza   genetika   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• receptory thrombopoetinu MeSH
• rekombinantní proteiny MeSH
• thrombopoetin MeSH