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1.
Oncogene ; 37(4): 439-449, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-28967901

RESUMO

Toll-like receptor 5 (TLR5) is considered an attractive target for anticancer immunotherapy. TLR5 agonists, bacterial flagellin and engineered flagellin derivatives, have been shown to have potent antitumor and metastasis-suppressive effects in multiple animal models and to be safe in both animals and humans. Anticancer efficacy of TLR5 agonists stems from TLR5-dependent activation of nuclear factor-κB (NF-κB) that mediates innate and adaptive antitumor immune responses. To extend application of TLR5-targeted anticancer immunotherapy to tumors that do not naturally express TLR5, we created an adenovirus-based vector for intratumor delivery, named Mobilan that drives expression of self-activating TLR5 signaling cassette comprising of human TLR5 and a secreted derivative of Salmonella flagellin structurally analogous to a clinical stage TLR5 agonist, entolimod. Co-expression of TLR5 receptor and agonist in Mobilan-infected cells established an autocrine/paracrine TLR5 signaling loop resulting in constitutive activation of NF-κB both in vitro and in vivo. Injection of Mobilan into primary tumors of the prostate cancer-prone transgenic adenocarcinoma of the mouse prostate (TRAMP) mice resulted in a strong induction of multiple genes involved in inflammatory responses and mobilization of innate immune cells into the tumors including neutrophils and NK cells and suppressed tumor progression. Intratumoral injection of Mobilan into subcutaneously growing syngeneic prostate tumors in immunocompetent hosts improved animal survival after surgical resection of the tumors, by suppression of tumor metastasis. In addition, vaccination of mice with irradiated Mobilan-transduced prostate tumor cells protected mice against subsequent tumor challenge. These results provide proof-of-concept for Mobilan as a tool for antitumor vaccination that directs TLR5-mediated immune response toward cancer cells and does not require identification of tumor antigens.


Assuntos
Adenoviridae/genética , Vacinas Anticâncer/uso terapêutico , Vetores Genéticos/uso terapêutico , NF-kappa B/imunologia , Neoplasias da Próstata/terapia , Receptor 5 Toll-Like/metabolismo , Adjuvantes Imunológicos/genética , Adjuvantes Imunológicos/metabolismo , Adjuvantes Imunológicos/uso terapêutico , Animais , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Vetores Genéticos/genética , Vetores Genéticos/imunologia , Humanos , Imunoterapia/métodos , Injeções Intralesionais , Células Matadoras Naturais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Peptídeos/genética , Peptídeos/imunologia , Peptídeos/metabolismo , Cultura Primária de Células , Próstata/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/mortalidade , Transdução de Sinais/imunologia , Receptor 5 Toll-Like/agonistas , Receptor 5 Toll-Like/genética , Receptor 5 Toll-Like/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Cell Death Dis ; 7: e2145, 2016 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-26986512

RESUMO

shRNA-mediated gene-silencing technology paired with cell-based functional readouts reveals potential targets directly, providing an opportunity to identify drugs against the target without knowing the precise role of the target in the pathophysiological processes of interest. By screening a lentiviral shRNA library targeting for major components of human signaling pathways and known drug targets, we identified and validated both canonical as well as 52 novel mediators of FAS and TNF ligand-induced apoptosis. Presence of potential therapeutic targets among these mediators was confirmed by demonstration of in vivo activity of siRNAs against four identified target candidates that protected mice from acute liver failure (ALF), a life-threatening disease with known involvement of death receptor (DR)-mediated apoptosis. Network-based modeling was used to predict small-molecule inhibitors for several candidate apoptosis mediators, including somatostatin receptor 5 (SSTR5) and a regulatory subunit of PP2A phosphatase, PPP2R5A. Remarkably, pharmacological inhibition of either SSTR5 or PPP2R5A reduced apoptosis induced by either FASL or TNF in cultured cells and dramatically improved survival in several mouse models of ALF. These results demonstrate the utility of loss-of-function genetic screens and network-based drug-repositioning methods for expedited identification of targeted drug candidates and revealed pharmacological agents potentially suitable for treatment of DR-mediated pathologies.


Assuntos
Apoptose/efeitos dos fármacos , Falência Hepática Aguda/tratamento farmacológico , Modelos Biológicos , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Receptor fas/antagonistas & inibidores , Animais , Apoptose/genética , Descoberta de Drogas , Feminino , Células HeLa , Humanos , Falência Hepática Aguda/genética , Falência Hepática Aguda/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Receptor fas/genética , Receptor fas/metabolismo
3.
Tsitologiia ; 57(1): 62-9, 2015.
Artigo em Russo | MEDLINE | ID: mdl-25872377

RESUMO

Morphology of a pelobiont Pelomyxa secunda (Gruber, 1884) comb. nov. was investigated at light- and electron-microscopical levels. Locomotive forms are elongated or cigar-shaped. The size of active forms varies from 200 to 300 µm. Larger individuals (up to 400 µm) are not able to directed movement. Organism can produce short, usually finger-shaped hyaline pseudopodia at the frontal side or laterally. The cell coat is represented by amorphous glycocalix, up to 300 nm in thickness. A thin periphery cytoplasmic zone is deprived of any organelles, vacuoles, endocytobionts and other inclusions and separated from main cytoplasm by a layer of arranged microfilaments. P. secunda is multinucleate organism; nuclei are of granular type. The nucleolar material is represented by two forms of discrete structures differing in size and electron density. Two or three layers of short microtubules organized in the parallel arrangement are associated with outer side of the nuclear envelop. P. secunda possess two types of obligate prokaryotic endocytobionts lying in individual symbiontophoric vacuoles. Undulipodia, kinetosomes and root microtubular derivatives are not observed in P. secunda cells as well as any developed cytoplasmic microtubular cytoskeleton.


Assuntos
Archamoebae/ultraestrutura , Citoesqueleto de Actina/ultraestrutura , Núcleo Celular/ultraestrutura , Citoplasma/ultraestrutura , Grânulos Citoplasmáticos/ultraestrutura , Glicocálix/ultraestrutura , Microscopia Eletrônica , Microtúbulos/ultraestrutura , Movimento , Pseudópodes/ultraestrutura , Simbiose/fisiologia , Vacúolos/ultraestrutura
4.
Tsitologiia ; 56(7): 536-9, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25696998

RESUMO

Heat shock proteins have been revealed for the first time by the methods of Western blotting using alkaline phosphatase and ECL in the cells of Porphyra purpurea from Kattegat area of the Baltic Sea in normal and experimental stress conditions. It was demonstrated with application of monoclonal anti-Hsp70 antibodies that a slight band about 70 kDa is present constitutively at the film; additionally the polypeptide of about 40 kDa ("Hsp40") has been detected. After heat shock at 28 degrees C during 1 hr significant "expenditure" of Hsp70 was observed, as well as the pronounced induction of "Hsp40"; the induction was expressed especially strongly in 24 hr after the stress application.


Assuntos
Adaptação Fisiológica/genética , Proteínas de Algas/genética , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP70/genética , Porphyra/genética , Proteínas de Algas/biossíntese , Proteínas de Algas/isolamento & purificação , Fosfatase Alcalina/química , Western Blotting , Expressão Gênica , Proteínas de Choque Térmico HSP40/biossíntese , Proteínas de Choque Térmico HSP40/isolamento & purificação , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/isolamento & purificação , Temperatura Alta , Medições Luminescentes , Porphyra/metabolismo , Estresse Fisiológico
5.
Tsitologiia ; 56(10): 770-8, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25711087

RESUMO

Morphology of a pelobiont Pelomyxa paradoxa Penard, 1902 was investigated at light- and electron-microscopical levels. Locomoting cells are cigar-shaped. The cells produce many hyaline pseudopodia of digital and conical form at lateral sides of the body. The organism has a pronounced hyaline bulbous uroid with broad peripheral zone of hyaloplasm and many conical hyaline villi. There is a thin layer of amorphous glycocalix at the cell surface. "Structure" and food vacuoles of different size are very abundant in the endoplasm. Two different species of prokaryote endocytobionts are peculiar for P. paradoxa. Uninucleate stage dominates in the life cycle of P. paradoxa. Usually there are no more than 10-12 nuclei in multinucleate forms of P. paradoxa. Pelomyxae nuclei are closely surrounded by thick multilaminar layer and additionally by one more layer, which is formed by small vesicles with electron-dense content. Several irregular-shaped nucleoli are situated at the nucleus periphery. Inside the nucleoli, and sometimes directly in nucleoplasm the small round bodies are revealed, these bodies being formed by tightly packed electron-dense fibrils. Many non-motile flagellae are located mainly in the uroidal zone of the cell. Pronounced lateral root and 50-60 radial microtubules originate from the electrone-dense muft around the kinetosome. All elements of the rootlet system of flagella are limited by peripheral layers of cytoplasm. P. paradoxa occupy an intermediate position between two groups of species of Pelomyxa genus--P. gruberi + P. prima and P. palustris + P. stagnalis + P. belewski, which differ greatly by the organization of their flagella basal apparatus.


Assuntos
Archamoebae/ultraestrutura , Estágios do Ciclo de Vida/fisiologia , Archamoebae/crescimento & desenvolvimento , Membrana Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Citoplasma/ultraestrutura , Flagelos/ultraestrutura , Glicocálix/ultraestrutura , Microtúbulos/ultraestrutura , Pseudópodes/ultraestrutura , Vacúolos/ultraestrutura
6.
Urologiia ; (2): 70-5, 2012.
Artigo em Russo | MEDLINE | ID: mdl-22876639

RESUMO

The aim of the study was investigation of morphological changes in the urinary bladder and ureteral wall of dogs in response to contact electroimpulse impact (CEII); to develop recommendations for utilization of contact electroimpulse lithotripsy in humans. Effects of single-impulse CEII on the bladder and ureteral mucosa produced by an electroimpulse lithotripter were studied in 23 mature mongrel dogs. The morphological material was studied immediately after the impact, 1, 6, 14 days and 1, 3, 6 and 12 months after it. The 0.1-0.7 J electroimpulse impact resulted in fragmentary epithelial necrosis and aceptic inflammation within a muscular layer. An enhanced to 0.8 J impact caused local damage to all layers of the wall including adventitium while a 0.9-1 J impact caused ureteral perforation in 3 cases. Duration of morphological rehabilitation depended on the impact power and was optimal for 0.1-0.5 J impulses with complete mucosal repair to day 14 and complete morphological rehabilitation to month 6 after the procedure. In power 0.6-1 J mucosal recovery increased to 1 month while complete formation of the connective tissue finished after 1 year. None cases of development of ureteral strictures after CEII was observed in follow-up for 1 year.


Assuntos
Terapia por Estimulação Elétrica , Uretra/patologia , Uretra/fisiopatologia , Bexiga Urinária/patologia , Bexiga Urinária/fisiopatologia , Animais , Cães , Feminino , Masculino
7.
Acta Naturae ; 3(1): 77-84, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22649675

RESUMO

Pattern-recognition receptors (PRR) play a crucial role in the induction of the defense reactions of the immune system against pathogenic bacterial and viral infections. The activation of PRR by specific, highly conserved pathogen-associated molecular patterns (PAMPs) induces numerous immune reactions related both to innate and adaptive immunity. In addition to the well-studied Toll-like receptors, pathogens can be recognized by the receptors belonging to the other PRR families; including NOD-like receptors (NLR). Stimulation of members of NOD-like receptors (NOD1, 2) and Toll-like receptors results in the activation of the transcriptional factor NF-kB regulating gene expression in numerous molecules implicated in the development of proinflammatory reactions. As opposed to Toll-like receptors, the NF-kB-activating ability of NLRs has not been fully studied. In this work, we examine the ability of one member of the NLR family - NOD1 - to activate the main proinflammatory transcriptional factor NF-kB. We also compare the NF-kB-activating ability of NOD1 ligands of a different structure with TLR4,5 ligandsin vitroandin vivo.

8.
Biochemistry (Mosc) ; 75(9): 1098-114, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21077829

RESUMO

Toll-like receptors (TLR) are among key receptors of the innate mammalian immune system. Receptors of this family are able to recognize specific highly conserved molecular regions (patterns) in pathogen structures, thus initiating reactions of both innate and acquired immune response finally resulting in the elimination of the pathogen. In this case every individual TLR type is able to bind a broad spectrum of molecules of microbial origin characterized by different chemical properties and structures. Recent data demonstrate the existence of a multistep mechanism of the TLR recognition of the pathogen in which, in addition to receptors proper, the involvement of different adapter molecules is necessary. However, functions of separate adapter molecules as well as the principles of formation of a multicomponent system of ligand-specific recognition are still not quite understandable. We describe all identified as well as possible (candidate) adapter TLR molecules by giving their brief characteristics, and we also propose generalized possible variants of the TLR ligand-specific recognition with involvement of adapter molecules.


Assuntos
Ligantes , Receptores Toll-Like/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Antígenos CD36/metabolismo , Drosophila , Humanos , Receptores de Lipopolissacarídeos/metabolismo , Antígeno 96 de Linfócito/metabolismo , Domínios e Motivos de Interação entre Proteínas , Transdução de Sinais , Receptores Toll-Like/análise , Receptores Toll-Like/química
9.
Artigo em Russo | MEDLINE | ID: mdl-20799402

RESUMO

AIM: Tests for Mycoplasma hominis, M. genitalium, Ureaplasma urealyticum in males with suspected prostate cancer. MATERIALS AND METHODS: Identification of mycoplasms was performed in prostate tissue samples using universal PCR as well as in serum samples of patients with suspected prostate cancer using ELISA for detection of IgG to M. hominis. Two hundred and fifty samples from each lobe of prostate were obtained from 125 patients with suspected prostate cancer by transrectal polyfocal biopsy. Blood samples were drawn from the same patients for ELISA. RESULTS: Out of 125 patients with suspected prostate cancer, 20.5% were positive for Mycoplasma by PCR. Between studied species, only M. hominis was found in big proportion of analyzed samples. Out of 118 serum samples, 30.5% were positive for IgG to M. hominis in ELISA. CONCLUSION: Fact of presence of Mycoplasma species in tissue of prostate was established in 20.5% pf patients with suspected prostate cancer. Obtained results show that M. hominis is frequently infects prostate tissue and that this infection was more common in patients with high grade prostatic interstitial neoplasia and prostate cancer than in patients with benign changes of prostate tissue or in persons without prostate disease. This allows to suggest that infection with M. hominis could play an important role in development of cancer.


Assuntos
Infecções por Mycoplasma/diagnóstico , Mycoplasma hominis/isolamento & purificação , Hiperplasia Prostática/microbiologia , Neoplasia Prostática Intraepitelial/microbiologia , Neoplasias da Próstata/microbiologia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , DNA Bacteriano/genética , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Mycoplasma/complicações , Mycoplasma genitalium/isolamento & purificação , Mycoplasma hominis/genética , Reação em Cadeia da Polimerase , Ureaplasma/isolamento & purificação , Infecções por Ureaplasma/complicações , Infecções por Ureaplasma/diagnóstico
10.
Tsitologiia ; 52(12): 1041-4, 2010.
Artigo em Russo | MEDLINE | ID: mdl-21427984

RESUMO

Our own studies of alterations in the level of constitutive heat shock protein of 70 kDa family (Hsp70) in freshwater (Paramecium jenningsi), meta-freshwater (Tetrahymena pyriformis) and curyhaline (P. nephridiatum) ciliates acclimated to salt-water and fresh-water medium were reviewed. It has been shown that the level of constitutive Hsp70 content correlates with the salinity-resistance of ciliate species: in P. jenning i it was lower in freshwater, than in marine water, in euryhaline P. nephridiatum it was higher in freshwater, than in marine water, and was more or less stable in T. pyriformis, the ciliate that occupies intermediate position between two mentioned above species according its salinity-resistance. The ecological importance of constitutive heat shock protein level is discussed in the context of salinity adaptations studies.


Assuntos
Adaptação Fisiológica/fisiologia , Cilióforos/metabolismo , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Protozoários/biossíntese , Salinidade , Cilióforos/citologia , Especificidade da Espécie
11.
Bull Exp Biol Med ; 148(2): 308-11, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20027355

RESUMO

The use of ultralow doses of antibodies to prostate-specific antigen (afala) for long-term treatment of benign prostatic hyperplasia in patients with moderate symptoms rapidly and effectively reduces irritative and obstructive symptoms, significantly decreases residual urine volume, and increases the rate of urination. Afala therapy is indicated for patients with stage I-II benign prostatic hyperplasia of moderately pronounced symptoms.


Assuntos
Anticorpos/uso terapêutico , Fatores Imunológicos/uso terapêutico , Hiperplasia Prostática/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Anticorpos/farmacologia , Humanos , Fatores Imunológicos/farmacologia , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/patologia , Resultado do Tratamento , Urodinâmica/efeitos dos fármacos
12.
Mol Gen Mikrobiol Virusol ; (2): 25-8, 2009.
Artigo em Russo | MEDLINE | ID: mdl-19517807

RESUMO

Various strains of mycoplasmas cause activation of transcriptional factor NF-kB as a result of interaction with different combinations of Toll-like receptors (TLR). It is well known that the MALP-2 protein of M. fermentans activates the NF-kB through interaction with the TLR2/6, lipid-associated membrane lipopeptides (LAMPs) of M. penetrans through the TLR1/2, LAMPs of M. pneumoniae through combinations of Toll-like receptors (TLR2/6 and TLR1/2), and superantigene of M. arthritidis through the TLR2 and TLR4-dependent pathways. In this study, we defined specific Toll-like receptors for LAMPs of M. arginini. For carrying out the research we used cell lines 293-null, 293-hTLR2, 293-hTLR1/2, 293-hTLR2/CD14, 293-hTLR2/6, 293-hTLR4/ CD14-MD2 expressing certain combinations of TLR and their coreceptors. It was shown that LAMPs of M. arginini cause activation of NF-kB interacting with TLR2/1, TLR2/6 and TLR2/ CD14, but not with TLR2 alone or TLR4.


Assuntos
Proteínas de Bactérias/metabolismo , Lipopeptídeos/metabolismo , Proteínas de Membrana/metabolismo , Mycoplasma/metabolismo , NF-kappa B/metabolismo , Peptídeos/metabolismo , Receptores Toll-Like/metabolismo , Linhagem Celular Transformada , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Mycoplasma/patogenicidade , Peptídeos/farmacologia , Regulação para Cima
13.
Urologiia ; (2): 32-7, 2009.
Artigo em Russo | MEDLINE | ID: mdl-19530326

RESUMO

Efficacy and safety of endoscopic contact electroimpulse lithotripsy (EILT) were studied in 146 patients with urolithiasis (mean age 48+/-16 years). Of them, 10 (7%) had ureteropelvic (UP) concrements, 124 (85%) had ureteroliths and 12 (8%) had bladder stones. The impulses were generated by the electroimpulse lithotripter Urolit-105M (Lithotech Medical, Israel; MedLine, Russia). EILT produced a complete destruction of UP concrements, ureteroliths and bladder stones in 96% cases. Complications occurred in 8.2% cases. The risk of intraoperative EILT complications was higher in destruction of stones more than 8 mm in the largest parameter of size, long-standing ureteral concrements complicated by ureteritis. EILT of UP concrements must be conducted by means of single impulses (impulse energy 0.45 J), of ureteroliths--by single or paired impulses (impulse energy 0.45-0.6 J), of bladder stones--by paired or serial impulses (impulse energy 0.6-0.7 J).


Assuntos
Litotripsia/instrumentação , Litotripsia/métodos , Urolitíase/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
14.
Oncogene ; 28(8): 1151-61, 2009 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-19137016

RESUMO

Acquisition of a transformed phenotype involves deregulation of several signal transduction pathways contributing to unconstrained cell growth. Understanding the interplay of different cancer-related signaling pathways is important for development of efficacious multitargeted anticancer drugs. The small molecule 9-aminoacridine (9AA) and its derivative, the antimalaria drug quinacrine, have selective toxicity for tumor cells and can simultaneously suppress nuclear factor-kappaB (NF-kappaB) and activate p53 signaling. To investigate the mechanism underlying these drug activities, we used a combination of two-dimensional protein separation by gel electrophoresis and mass spectrometry to identify proteins whose expression is altered in tumor cells by 9AA treatment. We found that 9AA treatment results in selective downregulation of a specific catalytic subunit of the phosphoinositide 3-kinase (PI3K) family, p110 gamma. Further exploration of this observation demonstrated that the mechanism of action of 9AA involves inhibition of the prosurvival AKT/mammalian target of rapamycin (mTOR) pathway that lies downstream of PI3K. p110 gamma translation appears to be regulated by mTOR and feeds back to further modulate mTOR and AKT, thereby impacting the p53 and NF-kappaB pathways as well. These results reveal functional interplay among the PI3K/AKT/mTOR, p53 and NF-kappaB pathways that are frequently deregulated in cancer and suggest that their simultaneous targeting by a single small molecule such as 9AA could result in efficacious and selective killing of transformed cells.


Assuntos
Aminacrina/farmacologia , Antineoplásicos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Aminacrina/química , Antineoplásicos/química , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Eletroforese em Gel Bidimensional , Perfilação da Expressão Gênica , Humanos , Imunoprecipitação , NF-kappa B/genética , NF-kappa B/metabolismo , Neoplasias/metabolismo , Neoplasias/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Quinases/metabolismo , Proteômica , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Serina-Treonina Quinases TOR , Transfecção , Proteína Supressora de Tumor p53/metabolismo
15.
Tsitologiia ; 51(12): 1019-24, 2009.
Artigo em Russo | MEDLINE | ID: mdl-20141038

RESUMO

The content of constitutive from of 70 kDa family heat shock pritein (Hsp70) was determined by the method of immunoblotting. 9 strains of representatives of the genus Acanthamoeba including 8 amphizoic (facultative parasitic) strains and one free-living (isolated from upper horizons of Arctic soils) were studied. We also examined 15 strains of free-living freshwater amoebae of various geographic origin, age and species. 14 of them belonging to the genus Amoeba and one to the genus Trichamoeba. The presence of Hsp70 was demonstrated in the cells of all 25 freshwater amoeba strains, whereas it was shown only for 2 of amphizoic acanthamoebae strains. In all these cases, the position of zone at the blot, revealed by monoclonal anti-HSP70 antibodies, corresponded to polypeptide with molecular mass about 70 kDa. We also found rather high level of constitutive Hsp70 in the cells of contemporary free-living tundra soil representative. However, in this case, the stained zone occupied the position corresponding to MW about 60 kDa which was just the same as earlier obtained for the ancient tundra acanthamoebae strain from permafrost.


Assuntos
Amoeba/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Protozoários/metabolismo
16.
Tsitologiia ; 50(7): 619-22, 2008.
Artigo em Russo | MEDLINE | ID: mdl-18771177

RESUMO

Alterations of Hsp70 level were studied in the cells of freshwater ciliate Tetrahymena pyriformis after medium salinity changes. It is shown that ciliates, acclimated to fresh water (0 per thousand) and to salt water of 2 and 10 per thousand have similar constitutive levels of Hsp70 in their cells. Neither pronounced induction of Hsp70, was not decrease of its level, revealed in ciliates after salinity stresses. These data differ from the results obtained while studying euryhaline ciliate Paramecium nephridiatum and strongly freshwater one Paramecium jenningsi. We presume that the differences in the mode of chaperone system reaction of these ciliates species might be connected with different extents of salinity persistence - the least in P. jenningsi, intermediate in T. pyriformis and the most pronounced in P. nephridiatum.


Assuntos
Adaptação Fisiológica , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Protozoários/metabolismo , Salinidade , Tetrahymena pyriformis/fisiologia , Animais , Água Doce/parasitologia , Tetrahymena pyriformis/metabolismo
17.
Oncogene ; 27(33): 4521-31, 2008 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-18408766

RESUMO

Prokaryotes of the genus Mycoplasma are the smallest cellular organisms that persist as obligate extracellular parasites. Although mycoplasma infection is known to be associated with chromosomal instability and can promote malignant transformation, the mechanisms underlying these phenomena remain unknown. Since persistence of many cellular parasites requires suppression of apoptosis in host cells, we tested the effect of mycoplasma infection on the activity of the p53 and nuclear factor (NF)-kappaB pathways, major mechanisms controlling programmed cell death. To monitor the activity of p53 and NF-kappaB in mycoplasma-infected cells, we used a panel of reporter cell lines expressing the bacterial beta-galactosidase gene under the control of p53- or NF-kappaB-responsive promoters. Cells incubated with media conditioned with different species of mycoplasma showed constitutive activation of NF-kappaB and reduced activation of p53, common characteristics of the majority of human tumor cells, with M. arginini having the strongest effect among the species tested. Moreover, mycoplasma infection reduced the expression level and inducibility of an endogenous p53-responsive gene, p21(waf1), and inhibited apoptosis induced by genotoxic stress. Infection with M. arginini made rat and mouse embryo fibroblasts susceptible to transformation with oncogenic H-Ras, whereas mycoplasma-free cells underwent irreversible p53-dependent growth arrest. Mycoplasma infection was as effective as shRNA-mediated knockdown of p53 expression in making rodent fibroblasts permissive to Ras-induced transformation. These observations indicate that mycoplasma infection plays the role of a p53-suppressing oncogene that cooperates with Ras in cell transformation and suggest that the carcinogenic and mutagenic effects of mycoplasma might be due to inhibition of p53 tumor suppressor function by this common human parasite.


Assuntos
Transformação Celular Neoplásica/metabolismo , Embrião de Mamíferos/metabolismo , Fibroblastos/metabolismo , Infecções por Mycoplasma/metabolismo , Mycoplasma/metabolismo , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/genética , Linhagem Celular , Transformação Celular Neoplásica/genética , Instabilidade Cromossômica/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Dano ao DNA/genética , Embrião de Mamíferos/microbiologia , Fibroblastos/microbiologia , Humanos , Camundongos , Infecções por Mycoplasma/genética , NF-kappa B/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Ratos , Elementos de Resposta/genética , Proteína Supressora de Tumor p53/genética
18.
Proc Natl Acad Sci U S A ; 105(17): 6302-7, 2008 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-18424558

RESUMO

Identification of unique features of cancer cells is important for defining specific and efficient therapeutic targets. Mutant p53 is present in nearly half of all cancer cases, forming a promising target for pharmacological reactivation. In addition to being defective for the tumor-suppressor function, mutant p53 contributes to malignancy by blocking a p53 family member p73. Here, we describe a small-molecule RETRA that activates a set of p53-regulated genes and specifically suppresses mutant p53-bearing tumor cells in vitro and in mouse xenografts. Although the effect is strictly limited to the cells expressing mutant p53, it is abrogated by inhibition with RNAi to p73. Treatment of mutant p53-expressing cancer cells with RETRA results in a substantial increase in the expression level of p73, and a release of p73 from the blocking complex with mutant p53, which produces tumor-suppressor effects similar to the functional reactivation of p53. RETRA is active against tumor cells expressing a variety of p53 mutants and does not affect normal cells. The results validate the mutant p53-p73 complex as a promising and highly specific potential target for cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Catecóis/farmacologia , Proteínas de Ligação a DNA/metabolismo , Proteínas Mutantes/metabolismo , Neoplasias/patologia , Proteínas Nucleares/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Tiazóis/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Antineoplásicos/química , Catecóis/química , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/genética , Ensaios de Seleção de Medicamentos Antitumorais , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Humanos , Camundongos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Bibliotecas de Moléculas Pequenas/química , Tiazóis/química , Transcrição Gênica/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/genética
19.
Oncogene ; 27(13): 1905-15, 2008 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-17906696

RESUMO

A major role for c-Myc in the proliferation of normal cells is attributed to its ability to promote progression through G(1) and into S phase of the cell cycle. The absolute requirement of c-Myc for cell cycle progression in human tumor cells has not been comprehensively addressed. In the present work, we used a lentiviral-based short hairpin RNA (shRNA) expression vector to stably reduce c-Myc expression in a large number of human tumor cell lines and in three different types of normal human cells. In all cases, cell proliferation was severely inhibited, with normal cells ultimately undergoing G(0)/G(1) growth arrest. In contrast, tumor cells demonstrated a much more variable cell cycle response with cells from several lines accumulating in S or G(2)/M phases. Moreover, in some tumor lines, the phase of cell cycle arrest caused by inhibition of c-Myc could be altered by depleting tumor suppressor protein p53 or its transcriptional target p21(CIP/WAF). Our data suggest that, as in the case of normal cells, c-Myc is essential for sustaining proliferation of human tumor cells. However its rate-limiting role in cell cycle control is variable and is reliant upon the status of other cell cycle regulators.


Assuntos
Ciclo Celular/fisiologia , Proliferação de Células , Neoplasias/metabolismo , Neoplasias/patologia , Proteínas Proto-Oncogênicas c-myc/deficiência , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Citometria de Fluxo , Proteínas de Fluorescência Verde/metabolismo , Humanos , Immunoblotting , Queratinócitos/citologia , Queratinócitos/metabolismo , Melanócitos/citologia , Melanócitos/metabolismo , Neoplasias/genética , Proteínas Proto-Oncogênicas c-myc/genética , RNA Interferente Pequeno/farmacologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
20.
Mol Gen Mikrobiol Virusol ; (4): 6-10, 2008.
Artigo em Russo | MEDLINE | ID: mdl-19172872

RESUMO

NF-kappaB is one of the main transcriptional factors that is responsible for cell survival under stresses. It was shown that various species of mycoplasma and their structural components were able to stimulate NF-kappaB activation as a result of their interaction with specific toll-like receptors on eukaryotic cell surface. Based on these studies, we suggested that activation of NF-kappaB in response to mycoplasmal infection could enhance the resistance of infected cells in response to proapoptotic stimuli. In this study we showed that infection of cells expressing toll-like receptors TLR2/6 with mycoplasma M. arginini leaded to suppression of apoptosis induced by chemotherapeutic agents (cisplatin, 5-fluorouracil, taxol).


Assuntos
Apoptose/fisiologia , Mycoplasma/fisiologia , NF-kappa B/metabolismo , Receptor 2 Toll-Like/biossíntese , Receptor 6 Toll-Like/biossíntese , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular , Cisplatino/farmacologia , Fluoruracila/farmacologia , Humanos , Paclitaxel/farmacologia
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