RESUMO
INVESTIGATION OBJECTIVE: IVF protocol efficacy estimation in women with expected suboptimal response depending on ovary stimulation mode. MATERIALS AND TECHNIQUE: A randomized controlled study embracing results of 51 IVF cycle in women with ovary suboptimal response. The suboptimal response prognostic analysis was performed basing on ≤9 oocyte cumulus complexes obtained in previous IVF programs, the presence of no less than 5-9 antral follicles in both oocytes and amount of anti-Mullerian Hormone ≥0,8 ng/mL. In Group I (n = 25), the stimulation was performed by recombinant corifollitropin alfa combined with highly purified urinary gonadotropin, while in Group II (n = 26) it was made by means of recombinant follitropin/lutropin alfa within the protocol of applying gonadotropin-releasing hormone antagonists. RESULTS: The total gonadotropin dose in Group II patients was authentically lower compared to Group I (pË,01). No statistical difference between the two studied groups was detected concerning the number of obtained oocytes, 2pn zygote, good-quality transferred embryos and clinical pregnancy rate (p>.05). Embryo cryopreservation was performed only for group-II patients. CONCLUSION: Corifollitropin alfa administration combined with highly purified menotropin in IVF cycles for suboptimal responders is quite effective, however, this strategy has no preference over other stimulation modes. The strategy of using recombinant follitropin/lutropin alfa can be promotive to IVF outcomes for suboptimal responders by means of embryo banking. ClinicalTrials.gov Identifier: NCT03177538.
Assuntos
Fertilização in vitro/métodos , Hormônio Foliculoestimulante Humano/administração & dosagem , Menotropinas/administração & dosagem , Indução da Ovulação/métodos , Adulto , Feminino , Humanos , Recuperação de Oócitos , Gravidez , Taxa de Gravidez , Proteínas Recombinantes/administração & dosagem , Resultado do TratamentoRESUMO
Purulent iliopsoitis is a quite rare and difficult disease regarding diagnosis and treatment. However, treatment outcomes are not so favorable, incidence of sepsis and mortality are still extremely high. Original up-to-date studies devoted to this issue were analyzed. The authors discuss the actual problems of etiology, pathogenesis, classification, clinical features, diagnosis and surgical treatment of iliopsoitis. Considering these data, they conclude that timely diagnosis and adequate surgical treatment are essential for favorable outcomes. Prevention of relapse is based on detection of possible cause of disease and its possible correction.
Assuntos
Abscesso do Psoas , Sepse , Humanos , Resultado do TratamentoRESUMO
AIM: To improve treatment of patients with non-lactating mastitis through the study of the course, diagnosis and surgical treatment. MATERIAL AND METHODS: The study included 336 women aged 18-72 years with non-lactating mastitis who were hospitalized into the clinic for the period 1999-2016. RESULTS: Main clinical variants of the disease, spectrum of pathogens and its relationship with clinical forms of mastitis were determined. Also early and long-term outcomes were evaluated followed by formulation of therapeutic and diagnostic concept of surgical care for non-lactating mastitis. Thus, good results were obtained in most cases (95.8% in early period and 92.6% in long-term period). CONCLUSION: Only differentiated approach to diagnostic and curative tactics will allow to achieve good cosmetic and functional results in these patients.
Assuntos
Mastite/diagnóstico , Mastite/cirurgia , Adolescente , Adulto , Idoso , Progressão da Doença , Feminino , Humanos , Pessoa de Meia-Idade , Adulto JovemRESUMO
INTRODUCTION: Despite the advances of modern medicine purulent-inflammatory diseases of soft tissues continue to occupy a leading position in surgical practice. Streptococcal surgical infection does not refer to specific category, but it has a number of significant features and its definition as separate type is necessary. MATERIAL AND METHODS: Based on the results of treatment of 312 patients with streptococcal infection of soft tissues we studied the prevalence of this disease in overall structure of surgical infection of soft tissue, main clinical courses are defined. We performed molecular genetic typing of pathogens that allows to predict the course of pathological process taking into account microorganism's characteristics. RESULTS AND DISCUSSION: On the basis of obtained data basic medical and diagnostic concept of surgical care for these patients depending on clinical course of disease was formulated. It allowed to improve significantly the results of treatment of such patients.
Assuntos
Desbridamento/métodos , Drenagem/métodos , Infecções dos Tecidos Moles/cirurgia , Infecções Estreptocócicas/cirurgia , Streptococcus/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Federação Russa/epidemiologia , Infecções dos Tecidos Moles/epidemiologia , Infecções Estreptocócicas/epidemiologia , Resultado do Tratamento , Adulto JovemRESUMO
AIM: To study the features of occurrence, diagnosis, clinical course of infectious arthritis of sternoclavicular joint, as well as to develop differentiated therapeutic tactics depending on the clinical form and stage of disease. MATERIAL AND METHODS: It was analyzed treatment of 18 patients with infectious arthritis of sternoclavicular joint aged 27 to 88 years who were hospitalized for the period 2008-2014. Acute or chronic forms were determined depending on clinical course and serous arthritis, para-articular phlegmon and osteoarthritis--according to nature of tissue damage. Hypothermia and blunt trauma were often preceded to onset of disease. Diabetes and drug addiction were present as comorbidities. Also disease as the variant of purulent metastasis in case of sepsis was noted. Bone scintigraphy, CT and magnetic resonance imaging are the most informative. RESULTS: Infectious arthritis of sternoclavicular joint often had hematogenous origin, and Staphylococcus aureus was the most common cause. At the stage of serous arthritis antibacterial therapy was effective. Incision and drainage were performed urgently in case of para-articular phlegmon. Sternoclavicular joint resection was performed usually in 2-3 months after subsidence of inflammation.
Assuntos
Artrite Infecciosa/cirurgia , Drenagem/métodos , Articulação Esternoclavicular , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Infecciosa/diagnóstico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios XAssuntos
Antibacterianos/uso terapêutico , Fraturas do Fêmur , Fêmur , Fixação de Fratura , Fraturas Espontâneas , Osteomielite , Adolescente , Fraturas do Fêmur/diagnóstico , Fraturas do Fêmur/etiologia , Fraturas do Fêmur/fisiopatologia , Fraturas do Fêmur/cirurgia , Fêmur/diagnóstico por imagem , Fêmur/patologia , Fixação de Fratura/efeitos adversos , Fixação de Fratura/instrumentação , Fixação de Fratura/métodos , Fraturas Espontâneas/diagnóstico , Fraturas Espontâneas/etiologia , Fraturas Espontâneas/fisiopatologia , Fraturas Espontâneas/cirurgia , Humanos , Assistência de Longa Duração/métodos , Masculino , Dispositivos de Fixação Ortopédica , Osteomielite/diagnóstico , Osteomielite/tratamento farmacológico , Osteomielite/fisiopatologia , Osteomielite/cirurgia , Reoperação/métodos , Resultado do TratamentoRESUMO
The conformation properties of clinically relevant hybrid macromolecular antioxidants (dextran hydrophobically modified by sterically hindered phenols) in aqueous solution were characterized by a combination of dynamic light scattering (DLS), size exclusion chromatography (SEC), and small-angle neutron scattering (SANS). We were able to split and analyze separately two different types of polydispersity -polydispersity over molecular weights and the one over substitution degree. The properties of the hybrid macromolecules are determined by the number of hydrophobic antioxidants in a single molecule. An insertion of hydrophobic groups into a hydrophilic chain changes the conformation of a single conjugate macromolecule. We have established that with the increasing of a number of hydrophobic antioxidant groups, a conformational transition occurs where a single conjugate undergoes a transition from a Gaussian coil conformation to a more compact structure.
Assuntos
Antioxidantes/química , Dextranos/química , Interações Hidrofóbicas e Hidrofílicas , Fenóis/química , Configuração de Carboidratos , Cromatografia em Gel , Hidrodinâmica , Luz , Difração de Nêutrons , Espalhamento de Radiação , Espalhamento a Baixo Ângulo , ViscosidadeRESUMO
Results of treatment of 223 patients with ostheomyelitis of various etiology and localization were analyzed. Such aspects as diagnostic difficulties, polifocal type of the disease, sepsis development on the background of pelvic ostheomyelitis were discussed. Ostheoscintygraphy, magnetic resonance imaging and computed tomography proved to be of highest diagnostic value by pelvic ostheomyelitis. The original method of surgical treatment of purulent sacroileitis with the use of combined (pelvic and extrapelvic) access was represented.
Assuntos
Antibacterianos/uso terapêutico , Fístula Cutânea/cirurgia , Osteomielite , Ossos Pélvicos/patologia , Ossos Pélvicos/cirurgia , Supuração/cirurgia , Adolescente , Adulto , Idoso , Doença Crônica , Terapia Combinada , Fístula Cutânea/etiologia , Fístula Cutânea/patologia , Fístula Cutânea/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Osteomielite/etiologia , Osteomielite/patologia , Osteomielite/fisiopatologia , Osteomielite/cirurgia , Ossos Pélvicos/lesões , Pelve/patologia , Úlcera por Pressão/complicações , Úlcera por Pressão/patologia , Supuração/etiologia , Supuração/patologia , Supuração/fisiopatologia , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
Chemotherapy and radiation therapy for cancer often have severe side effects that limit their efficacy. Because these effects are in part determined by p53-mediated apoptosis, temporary suppression of p53 has been suggested as a therapeutic strategy to prevent damage of normal tissues during treatment of p53-deficient tumors. To test this possibility, a small molecule was isolated for its ability to reversibly block p53-dependent transcriptional activation and apoptosis. This compound, pifithrin-alpha, protected mice from the lethal genotoxic stress associated with anticancer treatment without promoting the formation of tumors. Thus, inhibitors of p53 may be useful drugs for reducing the side effects of cancer therapy and other types of stress associated with p53 induction.
Assuntos
Antineoplásicos/efeitos adversos , Apoptose/efeitos dos fármacos , Raios gama/efeitos adversos , Neoplasias/terapia , Tolerância a Radiação/efeitos dos fármacos , Tiazóis/farmacologia , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Antineoplásicos/farmacologia , Benzotiazóis , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , DNA/biossíntese , Dano ao DNA , Fase G2/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Fatores de Tempo , Tolueno/farmacologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/fisiologia , Raios Ultravioleta/efeitos adversosRESUMO
Results of various skin plastic operations performed in 312 patients with soft-tissue infection were analyzed. The choice of the method depended on size and site of the wound, predisposing pathological process, age and general patient's condition. Differential approach to the choice of reconstruction method allowed satisfactory short-term results in 91,4% of patients. 80% of patients demonstrated good long-term results.
Assuntos
Procedimentos de Cirurgia Plástica/métodos , Infecção da Ferida Cirúrgica/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Retalhos Cirúrgicos , Infecção da Ferida Cirúrgica/patologia , Resultado do Tratamento , Cicatrização , Adulto JovemRESUMO
A detailed examination of 40 children with recurrent exudative otitis media (EOM) using enzyme immunoassay and polymerase chain reaction suggested that ENT pathology in the above children (EOM, adenoiditis, tonsillopharyngitis, sinusitis) may be a complication of acute or chronic Epstein-Barr virus infection (EBVI) because primary EBVI infection or its long-term persistence followed secondary immunodeficiency resulting in lymphoid system impairment and damage of upper airway epithelium. This causes a recurrent and persistent course of EOM. Etiotropic and pathogenetically sound treatment of children with recurrent EOM includes antiviral therapy, immunocorrection, rehabilitation with participation of pediatrician, immunologist, infection therapist.
Assuntos
Infecções por Vírus Epstein-Barr/complicações , Otite Média com Derrame/virologia , Testes de Impedância Acústica/métodos , Doença Aguda , Aciclovir/uso terapêutico , Antígenos CD/imunologia , Antivirais/uso terapêutico , Criança , Pré-Escolar , Doença Crônica , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/imunologia , Feminino , Humanos , Imunoglobulinas/imunologia , Lactente , Masculino , Otite Média com Derrame/imunologiaRESUMO
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 XenoenxertoAssuntos
Abscesso , Antibacterianos/administração & dosagem , Técnicas de Diagnóstico por Cirurgia , Drenagem/métodos , Testa/patologia , Osso Frontal , Osteomielite , Abscesso/complicações , Abscesso/fisiopatologia , Abscesso/cirurgia , Osso Frontal/diagnóstico por imagem , Humanos , Cuidados Intraoperatórios/métodos , Masculino , Testes de Sensibilidade Microbiana , Osteomielite/diagnóstico , Osteomielite/etiologia , Osteomielite/fisiopatologia , Osteomielite/terapia , Cintilografia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto JovemRESUMO
Anticancer drugs stimulate apoptosis in the hair follicles (HF) and cause hair loss, the most common side effect of chemotherapy. In a mouse model for chemotherapy-induced hair loss, we demonstrate that p53 is essential for this process: in contrast to wild-type mice, p53-deficient mice show neither hair loss nor apoptosis in the HF keratinocytes that maintained active proliferation after cyclophosphamide treatment. HF in p53 mutants are characterized by down-regulation of Fas and insulin-like growth factor-binding protein 3 and by increased expression of Bcl-2. These observations indicate that local pharmacological inhibition of p53 may be useful to prevent chemotherapy-associated hair loss.
Assuntos
Alopecia/induzido quimicamente , Antineoplásicos Alquilantes/toxicidade , Ciclofosfamida/toxicidade , Proteína Supressora de Tumor p53/fisiologia , Alopecia/etiologia , Alopecia/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Regulação para Baixo/efeitos dos fármacos , Feminino , Folículo Piloso/citologia , Folículo Piloso/efeitos dos fármacos , Folículo Piloso/metabolismo , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/biossíntese , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética , Regulação para Cima/efeitos dos fármacos , Receptor fas/biossíntese , Receptor fas/genéticaRESUMO
DNA damage leads to the stabilization of p53 protein and its translocation to the nucleus, resulting in activation or suppression of p53-responsive genes. However, a significant proportion of cell nuclei remain negative for p53 and p53-inducible cyclin-dependent kinase inhibitor p21waf1 after a single dose of gamma-irradiation. Quantitation of DNA content in p53-positive and -negative nuclei 4-6 h after 10 Gy of gamma-irradiation of human breast carcinoma MCF7 cells, fibrosarcoma HT1080 cells, and diploid skin fibroblasts showed that p53 and p21waf1 nuclear accumulation occurs predominantly in the G1 phase and at the beginning of the S phase of the cell cycle. The majority of the nuclei in late S phase and in G2-M phase remained p53- and p21waf1-negative. This suggests that there is a cell cycle window during which p53 can accumulate in the nucleus and activate expression of p21waf1. To determine whether cell cycle-dependent distribution of p53 is caused by cytoplasmic modifications of p53 protein or by properties of the nucleus, p53 localization was analyzed in multinucleated cells obtained by polyethylene glycol-mediated cell fusion. Dramatic differences in p53 accumulation were found among the nuclei in individual multinucleated cells. Distribution of p53-positive and -negative nuclei among the phases of the cell cycle was similar to that observed in a regular cell population. These results suggest that the observed differences in p53 accumulation in the nuclei of irradiated cells are determined by cell cycle-dependent nuclear functions. In contrast to p53, p21waf1 was equally distributed among the nuclei of multinucleated cells regardless of the stage of the cell cycle, indicating that the observed phenomenon is specific for p53.
Assuntos
Ciclo Celular/efeitos da radiação , Núcleo Celular/efeitos da radiação , Proteína Supressora de Tumor p53/metabolismo , Neoplasias da Mama , Ciclo Celular/fisiologia , Fusão Celular , Núcleo Celular/metabolismo , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/análise , Ciclinas/biossíntese , Inibidores Enzimáticos , Feminino , Fibroblastos , Fibrossarcoma , Raios gama , Humanos , Polietilenoglicóis , Pele , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/análise , Proteína Supressora de Tumor p53/efeitos da radiaçãoAssuntos
Fístula Cutânea , Fêmur , Necrose/cirurgia , Osteomielite , Infecções por Salmonella , Salmonella enteritidis/isolamento & purificação , Supuração/cirurgia , Adulto , Antibacterianos/uso terapêutico , Técnicas de Tipagem Bacteriana , Terapia Combinada , Fístula Cutânea/microbiologia , Fístula Cutânea/patologia , Fístula Cutânea/cirurgia , Desbridamento , Feminino , Fêmur/microbiologia , Fêmur/patologia , Fêmur/cirurgia , Humanos , Masculino , Necrose/etiologia , Necrose/patologia , Osteomielite/microbiologia , Osteomielite/patologia , Osteomielite/fisiopatologia , Osteomielite/terapia , Infecções por Salmonella/sangue , Infecções por Salmonella/complicações , Infecções por Salmonella/fisiopatologia , Infecções por Salmonella/terapia , Salmonella enteritidis/efeitos dos fármacos , Salmonella enteritidis/patogenicidade , Supuração/etiologia , Supuração/patologia , Resultado do TratamentoRESUMO
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/metabolismoRESUMO
Mammalian tissues differ dramatically in their sensitivity to genotoxic stress, although the mechanisms determining these differences remain largely unknown. To analyse the role of p53 and p21 in determination of tissue specificity to DNA damage in vivo, we compared the effects of gamma radiation on DNA synthesis on whole-body sections of wild type, p53-deficient and p21-deficient mice. A dramatic reduction in 14C-thymidine incorporation after gamma irradiation was observed in the majority of rapidly proliferating tissues of wild type and p21-/- but not in p53-/- mice, confirming the key role of p53 in determination of tissue response to genotoxic stress in vivo and suggesting that p53-mediated inhibition of DNA synthesis does not depend on p21. Rapid radiation induced p53-dependent apoptosis was mapped to the areas of high levels of p53 mRNA in radiation sensitive tissues analysed (white pulp in the spleen and bases of crypts in small intestine), indicating that p53 regulation at the mRNA level is a determinant of cellular sensitivity to genotoxic stress. High p53 mRNA expression is inherited as a recessive trait in cell-cell hybrids suggesting the involvement of a negative control mechanism in the regulation of p53 gene expression.
Assuntos
Ciclinas/fisiologia , Proteína Supressora de Tumor p53/fisiologia , Células 3T3 , Animais , Apoptose/efeitos da radiação , Divisão Celular/efeitos da radiação , Inibidor de Quinase Dependente de Ciclina p21 , Raios gama , Expressão Gênica/efeitos da radiação , Genes Dominantes , Genes Recessivos , Intestino Delgado/citologia , Intestino Delgado/patologia , Intestino Delgado/efeitos da radiação , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , RNA Mensageiro , Baço/citologia , Baço/patologia , Baço/efeitos da radiação , Proteína Supressora de Tumor p53/genética , Irradiação Corporal TotalRESUMO
p53 tumor suppressor gene controls cell response to a variety of stresses inducing growth arrest or apoptosis in damaged cells. It largely determines the sensitivity of tumor and normal cells to radiation and chemotherapy, and, therefore, defines both the efficacy and limitations of anti-cancer treatment. To determine molecular mechanisms of p53-dependent stress response in normal tissues we identified and compared the spectra of radiation-responsive genes in cells of different origin and p53 status using a cDNA array hybridization technique. The majority of genes identified were p53-dependent and cell type specific. Several of the new p53 responders encode known secreted growth inhibitory factors. This suggests that p53, in addition to its intrinsic antiproliferation activity, can cause 'bystander effect' by inducing export of growth suppressive stimuli from damaged cells to neighboring cells. Consistently, a p53-dependent accumulation of factors, which causes growth inhibitory effects in a variety of cell lines, was found after gamma irradiation in the media from established and primary cell cultures and in the urine of irradiated mice. Moreover, p53-dependent factors released by normal human fibroblasts potentiated the cytotoxic effect of a chemotherapeutic drug on co-cultivated tumor cells. This suggests a previously unknown role for normal cells in chemo- and radiation therapy of cancer.
Assuntos
Inibidores do Crescimento/metabolismo , Estresse Fisiológico/fisiopatologia , Células 3T3/citologia , Células 3T3/metabolismo , Células 3T3/efeitos da radiação , Animais , Antineoplásicos/farmacologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/genética , Divisão Celular/efeitos da radiação , Linhagem Celular , Raios gama , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Expressão Gênica/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Genes/genética , Genes/efeitos da radiação , Genes Supressores de Tumor/genética , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Tumorais Cultivadas/citologia , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/efeitos da radiação , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologiaRESUMO
The p53 tumor suppressor pathway is a key mediator of stress response that protects the organism from accumulating genetically altered and potentially cancerous cells by inducing growth arrest or apoptosis in damaged cells. However, under certain stressful conditions, p53 activity can result in massive apoptosis in sensitive tissues, leading to severe pathological consequences for the organism. One such situation is anticancer therapy that is often associated with general genotoxic stress, leading to p53-dependent apoptosis in the epithelia of the digestive tract and in the hematopoietic system. A chemical inhibitor of p53, capable of suppressing p53-mediated apoptosis, was shown to protect mice from lethal doses of gamma-radiation, making pharmacological suppression of p53 a perspective therapeutic approach to reduce the side-effects of cancer treatment. There are other situations, besides anti-cancer therapy, when humans are exposed to stressful conditions known to involve p53 activation, which, in extreme cases, could result in the development of life-threatening diseases. Here we review the experimental evidence on the role of p53 in tissue injuries associated with hypoxia (heart and brain ischemias) and hyperthermia (fever and burns), comparing these pathologies with the consequences of genotoxic stress of cancer treatment. The accumulated information points to the involvement of p53 in the generation of the pathological outcome of the above stresses, making them potential targets for the therapeutic application of p53 inhibitors.