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1.
Zhonghua Bing Li Xue Za Zhi ; 53(3): 230-236, 2024 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-38433049

RESUMO

Objective: To investigate the clinicopathological features, classification, and genetic characteristics of common lymphatic malformation (CLM) in superficial soft tissue. Methods: A retrospective study of 110 patients with the diagnosis of CLM at the Henan Province People's Hospital, China from August 2019 to August 2022 was performed. The clinicopathological features, relevant immunohistochemical (IHC) staining results, and fluorescence quantitative PCR of PIK3CA mutation were analyzed, and patients were followed up. Results: Among the 110 CLM patients, there were 53 males and 57 females; 65 cases (65/110, 59.1%) were first detected when the patients were≤2 years old. The most common location was the head and neck in 41 cases (41/110, 37.3%). Clinically, 102 cases (102/110, 92.7%) were solitary, 83 cases (83/110, 75.5%) were skin-colored, 69 cases (69/110, 62.7%) had indistinct borders, and 10 cases (10/110, 9.1%) had diffuse and severe macroscopic manifestations. There were 52 macrocystic type (52/110, 47.3%), 23 microcystic type (23/110, 20.9%), and 35 combined type (35/110, 31.8%). The macrocystic CLM presented as soft, translucent masses with large cystic cavities on the cut surface, and histologically they were composed of large, irregularly dilated channels that were thicker with irregular smooth muscle and lymphocytic infiltration. Microcystic CLM showed wartlike projections or translucent blisters on the skin, with small honeycomb structures on the cut surface, and histologically consisted of round or angular dilated small lymphatic vessels with little or no smooth muscle. The combined CLM had both macrocystic and microcystic morphologies. IHC staining showed that the lymphatic endothelial cells were positive for LYVE-1, D2-40, PROX1, CD31, and VEGFR3 but negative for CD34; in the macrocystic and combined CLM vessel walls were positive for SMA. Eight of 13 CLM had PIK3CA mutation. All patients were followed up, and 24 (24/110, 21.8%) had relapses, which more frequently occurred in combined type, followed by microcystic type. Conclusions: CLM is a congenital vascular malformation composed of dilated, abnormal lymphatic channels, with PIK3CA mutation. There are significant differences in clinicopathological characteristics among the different types. Since microcystic and combined CLM are prone to recurrence, accurate pathological subtyping is necessary to guide treatment and to predict prognosis.


Assuntos
Cistos , Células Endoteliais , Feminino , Masculino , Humanos , Pré-Escolar , Estudos Retrospectivos , Antígenos CD34 , China , Classe I de Fosfatidilinositol 3-Quinases/genética
2.
Zhonghua Bing Li Xue Za Zhi ; 52(10): 1001-1005, 2023 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-37805390

RESUMO

Objective: To investigate the clinicopathological features of glomuvenous malformation (GVM). Methods: Thirty-one cases of GVM diagnosed at the Henan Provincial People's Hospital from January 2011 to December 2021 were collected. Their clinical and pathological features were analyzed. The expression of relevant markers was examined using immunohistochemistry. The patients were also followed up. Results: There were 16 males and 15 females in this study, with an average age of 11 years (range, 1-52 years). The locations of the disease included 13 cases in the limbs (8 cases in the upper limbs, 5 cases in the lower limbs), 9 cases in the trunks, and 9 cases in the foot (toes or subungual area). Twenty-seven of the cases were solitary and 4 were multifocal. The lesions were characterized by blue-purple papules or plaques on the skin surface, which grew slowly. The lumps became larger and appeared to be conspicuous. Microscopically, GVM mainly involved the dermis and subcutaneous tissue, with an overall ill-defined border. There were scattered or clustered irregular dilated vein-like lumens, with thin walls and various sizes. A single or multiple layers of relatively uniform cubic/glomus cells were present at the abnormal wall, with scattered small nests of the glomus cells. The endothelial cells in the wall of abnormal lumen were flat or absent. Immunohistochemistry showed that glomus cells strongly expressed SMA, h-caldesmon, and collagen IV. Malformed vascular endothelial cells expressed CD31, CD34 and ERG. No postoperative recurrence was found in the 12 cases. Conclusions: GVM is an uncommon type of simple venous malformation in the superficial soft tissue and different from the classical glomus tumor. Morphologically, one or more layers of glomus cells grow around the dilated venous malformation-like lumen, which can be combined with common venous malformations.


Assuntos
Tumor Glômico , Paraganglioma Extrassuprarrenal , Masculino , Feminino , Humanos , Criança , Tumor Glômico/cirurgia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Paraganglioma Extrassuprarrenal/metabolismo , Paraganglioma Extrassuprarrenal/patologia , Imuno-Histoquímica
4.
Eur Rev Med Pharmacol Sci ; 25(11): 3981-3989, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34156675

RESUMO

OBJECTIVE: Oral squamous cell carcinoma (OSCC) accounts for 90% of head and neck cancers, and its 5-year overall survival is very poor. MiR-150 is usually downregulated and acts as tumor suppressor in multiple cancers. The aim of our study is to explore the functions of miR-150 in OSCC. PATIENTS AND METHODS: Expressions of miR-150 and HMGA2 mRNA in OSCC tissues and cells were analyzed by qRT-PCR. Methyl Thiazolyl Tetrazolium (MTT) and transwell assays were conducted to assess the cell viability and invasive abilities. Western blot was conducted to assess the protein levels of epithelial-mesenchymal transition (EMT) markers. Luciferase reporter assay was carried out to verify miR-150 directly binding to HMGA2 in SCC25 cells. RESULTS: MiR-150 was low expressed and HMGA2 was highly expressed in OSCC tissues and cells. Downregulation of miR-150 or upregulation of HMGA2 predicted poor prognosis of OSCC patients. MiR-150 overexpression inhibited the abilities of viability, invasive and the EMT by targeting HMGA2 in OSCC cells. HMGA2 was a target gene of miR-150 and its expression was regulated by altering the expression of miR-150 in OSCC cells. HMGA2 reversed partial roles of miR-150 on cell viability and invasion in OSCC. CONCLUSIONS: MiR-150 impaired cell viability, invasion and EMT via binding to HMGA2 of OSCC. Our research demonstrates that miR-150 plays a critical role in the progression of OSCC. miR-150 might be a candidate molecular marker and a novel therapy target for OSCC patients.


Assuntos
Proteína HMGA2/genética , Neoplasias de Cabeça e Pescoço/genética , MicroRNAs , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Sobrevivência Celular/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Proteína HMGA2/metabolismo , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Estimativa de Kaplan-Meier , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade
5.
Eur Rev Med Pharmacol Sci ; 25(8): 3226-3234, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33928608

RESUMO

OBJECTIVE: The important regulatory mechanism of lncRNA PRNCR1 has been emphasized in malignant tumors. However, the role of lncRNA PRNCR1 remains unclear in oral squamous cell carcinoma (OSCC). The purpose of this study is to reveal the role of lncRNA PRNCR1 in OSCC. PATIENTS AND METHODS: RT-qPCR was used to detect mRNA expression. The functional mechanism of lncRNA PRNCR1 in OSCC was investigated by CCK-8, transwell and Luciferase reporter assays. RESULTS: LncRNA PRNCR1 was upregulated in OSCC and promoted cell proliferation, migration and invasion. LncRNA PRNCR1 directly binds to miR-326. The mutual inhibition between the expressions of lncRNA PRNCR1 and miR-326 was identified in OSCC. In addition, miR-326 restrained cell proliferation, migration and invasion in OSCC. Further, miR-326 directly targets FSCN1. FSCN1 expression was positively regulated by lncRNA PRNCR1 in OSCC. And FSCN1 promoted the progression of OSCC and aggravated the carcinogenic effect of lncRNA PRNCR1 in OSCC. CONCLUSIONS: LncRNA PRNCR1 promotes the progression of OSCC by functioning as a miR-326 'sponge' to upregulate FSCN1 expression.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Proteínas de Transporte/metabolismo , MicroRNAs/metabolismo , Proteínas dos Microfilamentos/metabolismo , Neoplasias Bucais/metabolismo , RNA Longo não Codificante/metabolismo , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Proteínas de Transporte/genética , Proliferação de Células , Células Cultivadas , Feminino , Humanos , Masculino , MicroRNAs/genética , Proteínas dos Microfilamentos/genética , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , RNA Longo não Codificante/genética
6.
Eur Rev Med Pharmacol Sci ; 22(8): 2343-2350, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29762838

RESUMO

OBJECTIVE: Glioma is a tumor of the brain. Although the clinical regimens and surgical techniques for glioma have improved, therapies of advanced glioma remain challenging, carrying dismal overall survival and therapeutic success rates. Evidence has shown that miRNAs played important roles in glioma development. The current study aimed at investigating the function of a novel cancerogenic miRNA, miR-93, in glioma progression by investigating the expression and mechanism of it. PATIENTS AND METHODS: qRT-PCR was conducted to assess the miR-93 expression and the mRNA expression of target gene in glioma tissues and cells. The invasion and migration abilities of the glioma cells were determined by transwell assays. Luciferase reporter assay was performed to confirm the target of miR-93. RESULTS: The results indicated that miR-93 expression in glioma tissues and cells was increased significantly than that in normal brain tissues and cells. Furthermore, miR-93 promoted glioma cell migration and invasion. RBL2 was recognized as a direct target of miR-93 in glioma cells, and overexpression of RBL2 could reverse the stimulative effect of miR-93 in glioma cell. CONCLUSIONS: The above findings suggested that miR-93 together with RBL2 could be diagnostic targets and novel prognostic markers for glioma.


Assuntos
MicroRNAs/metabolismo , Proteína p130 Retinoblastoma-Like/metabolismo , Regiões 3' não Traduzidas , Antagomirs/metabolismo , Sequência de Bases , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Glioma/patologia , Humanos , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , Mutagênese , Proteína p130 Retinoblastoma-Like/química , Proteína p130 Retinoblastoma-Like/genética , Alinhamento de Sequência
7.
Zhonghua Yu Fang Yi Xue Za Zhi ; 51(5): 386-392, 2017 May 06.
Artigo em Chinês | MEDLINE | ID: mdl-28464587

RESUMO

Objective: To investigate the combined impact of lifestyle factors on stomach cancer risk. Methods: We analyzed the data from the Shanghai Men's Health Study (SMHS) (2002-2013). The SMHS was conducted in eight neighborhood communities of urban Shanghai. From 2002 through June 2006, 61 480 residents aged 40 to 74 years old with no history of cancer were recruited. Failure time was the date of stomach cancer incidence, death or date of the last follow-up (December 31, 2013). The first two in-person follow-up surveys were conducted in 2004-2008, and 2008-2011, respectively. Using data on lifestyle, the healthy lifestyle index (HLI) was developed. The following lifestyle factors were included: smoking, alcohol consumption, diet habit, overweighted and physical activity. Cox proportional hazard models were used to evaluate the association of stomach cancer risk with lifestyle factors and HLI. Results: Over 9.28 years' follow-up, 477 incident cases of stomach cancer were identified from 59 503 study participants. Participants with zero, one, two, three, four, and five favorable lifestyle behaviors accounted for 3.44% (n=2 045), 18.14% (n=10 793), 33.68% (n=20 041), 29.43% (n=17 511), 12.82% (n=7 627), and 2.50% (n=1 486), respectively. Among all the five lifestyle factors, smoking and alcohol use were significantly related to stomach cancer risk. The relative risk of stomach cancer was 0.71 (95%CI: 0.57-0.87) for those who never smoked or quitted smoking for no less than 10 years and 0.70 (95%CI: 0.55-0.90) for those who consumed alcohol no more than 14 drinks per week. For each increment of healthy lifestyle index, the relative risk of stomach cancer was 0.86 (95%CI: 0.79-0.95). Compared to men with none or one healthy lifestyle factor, the relative risk for those with four or five was 0.62 (95%CI: 0.46-0.83). When we rebuilt HLI using more categories of each lifestyle factors, the HLI ranged from 0 to 11. For each point increase, the relative risk of stomach cancer was 0.93 (95%CI: 0.89-0.97). Compared those with 0 to 3 points, the relative risk of those with 8 to 11 points was 0.64 (95%CI: 0.47-0.87). Conclusion: In the SMHS, only a small proportion of men adhered to all the five healthy lifestyle factors. Compared to those with none or one healthy lifestyle behaviors, those with five may prevent about 1/3 stomach cancer incidence and the HLI was inversely associated with stomach cancer risk.


Assuntos
Povo Asiático/estatística & dados numéricos , Dieta , Estilo de Vida , Neoplasias Gástricas/etnologia , Adulto , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/epidemiologia , China , Exercício Físico , Estilo de Vida Saudável , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Sobrepeso/epidemiologia , Vigilância da População/métodos , Modelos de Riscos Proporcionais , Estudos Prospectivos , Risco , Fatores de Risco , Fumar/efeitos adversos , Fumar/epidemiologia , Inquéritos e Questionários
8.
Transplant Proc ; 37(1): 450-2, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15808673

RESUMO

Adenovirus-mediated gene transfer has been widely used in gene therapy for congenital metabolic, cardiovascular, and malignant diseases. It has been reported that a gene transfer technique into transplanted organs may suppress rejection reactions and inhibit preservation injury. However, the magnitude of transgene expression in organs preserved at a cold temperature remains to be determined. In this study, we compared the transgene expression using vascular endothelial growth factor receptor (VEGFR)-mediated adenoviral vector at cold versus warm temperatures alone and combined with hyperbaric oxygen in cold-preserved organs. The transgene expression by porcine endothelial cells transduced with adenoviral vector was significantly higher after a 24 hour-incubation at warm temperature than after a 1 hour-incubation with warm or cold temperature. Moreover, the transgene expression of after a 1-hour incubation at cold temperature was significantly lower than a 1-hour incubation at warm temperature. The VEGFR-mediated adenoviral vector augmented transgene expression during a 1-hour incubation at cold temperature compared to the control vector. A/J skin graft survival in C3H mice was significantly prolonged compared to control or standard vector with CTLA4Ig cDNA using VEGFR-mediated adenoviral vector with CTLA4Ig cDNA in a 1-hour cold preservation. Furthermore, combined use of VEGFR-mediated adenoviral vector with CTLA4Ig cDNA plus FK506 showed an augmented effect on graft prolongation. It is concluded that adenovirus-mediated gene transfer in 1-hour cold-preserved organ is difficult compared to that in the warm condition. However, VEGFR-mediated gene transfer can augment the transgene expression in 1-hour cold-preserved organs, followed by the effective suppression of rejection reactions in allogeneic transplantation.


Assuntos
Endotélio Vascular/fisiologia , Oxigenoterapia Hiperbárica , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Abatacepte , Adenoviridae , Animais , Animais Geneticamente Modificados , Células COS , Linhagem Celular Tumoral , Chlorocebus aethiops , Neoplasias do Colo , Vetores Genéticos , Rejeição de Enxerto , Imunoconjugados/genética , Camundongos , Camundongos Endogâmicos A , Camundongos Endogâmicos C3H , Preservação de Órgãos , Transplante de Pele/imunologia , Suínos , Transplante Homólogo
9.
Eur J Clin Nutr ; 58(12): 1604-11, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15199383

RESUMO

BACKGROUND: In 1997, we launched a large population-based cohort study, the Shanghai Women Health Study (SWHS), to investigate diet in relation to cancer risk among 74 943 Chinese women. Simultaneously, a dietary calibration study was conducted among 200 SWHS participants with biweekly 24-h dietary recall (24HDR) over a 1-y period in order to evaluate the validity and reliability of the SWHS food frequency questionnaire (FFQ). OBJECTIVE: The objectives of the current study were to evaluate the nature and magnitude of variances for intake of 26 nutrients among SWHS participants, and to estimate the number of 24HDR needed for estimate intake of the 26 nutrients examined in the study population. DESIGN: In all, 1-y biweekly 24HDR collected from 200 healthy, free-living women aged between 40 and 70 y, who participated in the SWHS dietary calibration study, was analyzed by mixed effects model and ratios of within-individual and between-individual dietary intake variances (sigma(w)(2)/sigma(b)(2)) were estimated. RESULTS: In agreement with reports from studies conducted in the US, we found that within-individual variances were larger than between-individual variances in dietary intake of most nutrients. The sum of all other variation (eg, weekday and weekend, seasonal, interviewer) accounted for less than 5% of total variation. Ratios of within- to between-individual variances (for log transformed data) ranged from 1.05 (carbohydrate) to 2.79 (fat) for macronutrient intake, 1.74 (niacin) to 8.48 (delta-tocopherol) for vitamin intake, and 1.35 (phosphorus) to 5.59 (sodium) for mineral intake. CONCLUSIONS: The results of this study suggest that within- and between-individual differences in nutrient intake are the major sources of variation in this population of adult Chinese women. Cultural practices as well as seasonal supply and consumption patterns of vegetable intake are likely the major contributors to the variation. Implications of these results are discussed.


Assuntos
Dieta/normas , Inquéritos e Questionários/normas , Adulto , Idoso , Calibragem , China , Estudos de Coortes , Inquéritos sobre Dietas , Feminino , Humanos , Rememoração Mental , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estações do Ano , Sensibilidade e Especificidade , Verduras
10.
Neurosci Lett ; 282(3): 200-2, 2000 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-10717426

RESUMO

Adenosine, an endogenous modulator of synaptic transmission, has been implicated in regulation of sleep and arousal. The effect of adenosine on neuronal excitability depends on its concentration in the extracellular space. The present study shows that the state of activity of laboratory rats determines the level of tonic inhibition by adenosine in hippocampal slices prepared from these animals. Thus, slices taken at the end of the active period showed significantly more inhibition by adenosine, as determined by the effects of the A1 receptor blocker 8-CPT, in comparison to slices taken in the inactive state. The results support the proposed role of adenosine in regulation of sleep and arousal and point to the importance of the time of day at which slices for electrophysiological experiments are prepared.


Assuntos
Adenosina/fisiologia , Ritmo Circadiano , Hipocampo/fisiologia , Transmissão Sináptica/fisiologia , Animais , Potenciais Pós-Sinápticos Excitadores , Técnicas In Vitro , Masculino , Ratos , Ratos Wistar
11.
Yao Xue Xue Bao ; 27(11): 824-9, 1992.
Artigo em Chinês | MEDLINE | ID: mdl-1300026

RESUMO

A synthetic analogue of hainanensine 2a was further modified in order to improve its antitumor activity. Six compounds 3-8, were obtained, and among these compounds 8 showed significant activity. The diastereomer (+/-)8B was resolved by (+) tartaric acid and (-)benzoyl-tartaric acid to the corresponding enantiomers (-)8B and (+)8B, respectively and their optical purities were determined by isotope dilution method as 93% and 96%. The antitumor activity of the newly obtained compounds were tested in vitro, and (-)8B was found to have an IC50 of 1.9 mol/L, eighteen times higher than the original compound 2a.


Assuntos
Antineoplásicos Fitogênicos/síntese química , Harringtoninas/síntese química , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/uso terapêutico , Harringtoninas/química , Harringtoninas/uso terapêutico , Leucemia L1210/tratamento farmacológico , Camundongos , Estrutura Molecular
12.
J Interferon Res ; 11(1): 33-40, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1709417

RESUMO

2',5'-Linked oligoadenylates of varying chain lengths (2,5As) are formed from ATP by an interferon (IFN)-induced enzyme, 2',5'-oligoadenylate synthetase (2-5A synthetase). To identify these multiple forms, a method was devised utilizing electrophoretic separation of 32P-labeled 2,5As in a thin 20% polyacrylamide gel containing 7 M urea. A mixture of 2,5As synthesized from rat liver nuclear suspension was fractionated by this method. Each species was eluted from the gel for characterization by specific nucleotidylic enzymes. All major species in the gel were identified, including dimeric, trimeric, and tetrameric forms with either 5' tri- or diphosphates, as well as dephosphorylated species. Thus, in a single step, this method produced a more complete assessment of newly synthesized 2,5As and their degradative products than conventional, multistep DEAE-cellulose chromatography. It also allowed more rapid screening of multiple samples than high-pressure liquid chromatography (HPLC). This method, used to assay 2-5A synthetase induction by IFN-alpha in human T-cell H9 and CEM-CM3 lines, should be applicable for routine analysis of clinical specimens.


Assuntos
Nucleotídeos de Adenina/análise , Oligorribonucleotídeos/análise , 2',5'-Oligoadenilato Sintetase/análise , Animais , Fracionamento Químico , Cromatografia DEAE-Celulose , Eletroforese em Gel de Poliacrilamida , Humanos , Técnicas In Vitro , Interferons/farmacologia , Ratos , Ratos Endogâmicos , Linfócitos T/efeitos dos fármacos
14.
15.
Proc Soc Exp Biol Med ; 186(1): 60-3, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3628252

RESUMO

Various rat mammary tumors were analyzed for the presence of a milk-specific Ca2+-stimulated RNase (Ca2+-RNase). When crude extracts of some differentiated tumors--adenocarcinomas of MT/W9, MT/W9a, R3230AC, DMBA-1, DMBA-8, and DMBA-14 and 3MN squamous cell carcinoma--were assayed for RNase activity under various ionic conditions, it was always highest in the presence of Ca2+/EDTA than under any other ionic condition. The opposite was true in invasive MT/W449a and 13762 adenocarcinomas, poorly differentiated SMT/2A carcinomas, MAMF2/TC fibrosarcoma, and MT/A fibroadenoma. Sephacryl S-200 chromatography separation of tumor extracts confirmed the presence of Ca2+-RNase in those differentiated tumors and absence of the enzyme from other tumors. Expressing the activity as a ratio of Ca2+/EDTA to either Mg2+/EDTA or EDTA alone to more clearly represent the relative level of Ca2+-RNase activity further illustrates the distinct differences between tumor classes. Thus Ca2+-RNase is a sensitive marker for use in the characterization of rat tumors with respect to differentiated mammary functions.


Assuntos
Neoplasias Mamárias Experimentais/patologia , Proteínas de Neoplasias/análise , Ribonucleases/análise , Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Adenofibroma/enzimologia , Adenofibroma/patologia , Animais , Cálcio/farmacologia , Carcinoma/enzimologia , Carcinoma/patologia , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/patologia , Diferenciação Celular , Feminino , Fibrossarcoma/enzimologia , Fibrossarcoma/patologia , Neoplasias Mamárias Experimentais/enzimologia , Neoplasias Hormônio-Dependentes/enzimologia , Neoplasias Hormônio-Dependentes/patologia , Ratos
16.
Biochem Biophys Res Commun ; 145(1): 291-7, 1987 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-2439079

RESUMO

Viral reverse transcriptase activity was inhibited in a concentration dependent manner by 2',5'-oligoadenylate. Kinetically this inhibition was of a mixed type where 2',5'-oligoadenylate was not strictly competitive with dTTP. The potency of inhibition was more marked in the absence than in the presence of sulfhydryl agents. 2',5'-oligoadenylate had no effect on DNA-dependent E. coli DNA polymerase and was much less active against mammalian DNA polymerases. This is the first report of reverse transcriptase inhibition by an inducible constitutive natural ligand.


Assuntos
Nucleotídeos de Adenina/farmacologia , Vírus da Leucose Aviária/enzimologia , Vírus da Mieloblastose Aviária/enzimologia , Vírus do Sarcoma Aviário/enzimologia , Vírus da Leucemia Murina de Moloney/enzimologia , Oligorribonucleotídeos/farmacologia , Inibidores da Transcriptase Reversa , Animais , DNA Polimerase Dirigida por DNA/metabolismo , Escherichia coli/enzimologia , Cinética , Especificidade da Espécie
17.
Int J Biochem ; 19(5): 461-6, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3595993

RESUMO

Extracts of whole tissue or isolated nuclei from lactating rat mammary gland that has diminished cell replication capacity were more active than the corresponding extracts of pregnant rat mammary gland that contains actively replicating cells in causing a dose-dependent inhibition of DNA polymerase alpha in vitro. Purification of the inhibitor from both tissue and nuclear extracts using a sequence of Sephacryl S200, DEAE-cellulose and CM52 columns confirmed the above assay results. Using the same assay and purification procedures, both tissue and nuclear extracts from the rapidly growing transplanted R3220AC mammary tumors exhibited very little or no inhibitor activity. The partially purified mammary inhibitor (mol. wt of 155kD, high A280 nm/A260 nm ratio, heat labile) was equally inhibitory to the purified DNA polymerase alpha from either R3230AC tumor or calf thymus, and to the nuclear matrix bound DNA polymerase alpha of R3230AC tumor.


Assuntos
DNA Polimerase II/antagonistas & inibidores , Glândulas Mamárias Animais/fisiologia , Neoplasias Mamárias Experimentais/fisiopatologia , Extratos de Tecidos/isolamento & purificação , Animais , Bovinos , Linhagem Celular , Núcleo Celular/enzimologia , Feminino , Cinética , Neoplasias Mamárias Experimentais/enzimologia , Peso Molecular , Ratos , Ratos Endogâmicos F344 , Timo/enzimologia , Extratos de Tecidos/fisiologia
18.
Cancer Res ; 46(12 Pt 1): 6207-10, 1986 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3779641

RESUMO

Since interferon inducible 2',5'-oligoadenylate (2,5An) synthetase activity is present in a wide variety of cells and is affected by various hormonal conditions, primary human mammary tumor extracts were examined for the constitutive presence of this enzyme and its possible relationship with the various hormonal receptor levels in these tissues. Further, since 2,5An synthetase has been implicated as a possible factor controlling cell replication, we assayed DNA polymerases in these same tumor extracts to determine any correlation between 2,5An synthetase activity and growth potential. A survey of the soluble extracts from 24 different surgically removed human mammary tumor specimens for 2,5An synthetase activity indicated that this enzyme was indeed present in all extracts but in widely varying amounts of activity (31-2,666 nmol adenosine 5'-phosphate incorporated/mg protein). The 2,5An synthesized in the enzymic reactions ranged in size from di- to hexamers, with trimers being the abundant 2,5An in the majority of tumors. A comparison of the assay results for estrogen and progestin receptors with 2,5An synthesis indicated that high 2,5An synthetase activity was found in both estrogen or progestin positive and negative tumors. Thus, 2,5An synthetase activity was unrelated (r = 0.329 and 0.077, respectively, for estrogen and progestin receptors) to the hormonal receptor content of these tumors. A similar comparison was made between 2,5An synthesis and assay results for the activities of DNA polymerase alpha, regarded as the principal DNA replicating enzyme, and DNA polymerase beta, regarded as the DNA repair enzyme. Although the activity of the polymerases were also quite varied, the majority of tumor extracts demonstrated higher alpha polymerase activity with no parallel difference between the alpha and beta enzymes. There was, however, a weak correlation (r = 0.751) between 2,5An synthetase activity and DNA polymerase alpha activity among the tumors examined. Less of a correlation existed with DNA polymerase beta activity (r = 0.600). These results suggested that the potential of the tumors to synthesize 2,5An was unrelated to their hormonal responsiveness and only weakly related to their growth potential reflected by DNA polymerase alpha activity.


Assuntos
2',5'-Oligoadenilato Sintetase/análise , Neoplasias da Mama/enzimologia , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Neoplasias da Mama/análise , Neoplasias da Mama/patologia , DNA Polimerase II/análise , Feminino , Humanos
19.
Biochim Biophys Acta ; 868(1): 24-9, 1986 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-3756167

RESUMO

DNA polymerase alpha activity was markedly higher in all nuclear subfractions, including nuclear matrix, from transplanted R3230AC mammary adenocarcinomas than in the analogous fractions from mammary gland of same tumor-bearing pregnant or lactating rats. Changes in host lactational status had no significant effect on subnuclear distribution of tumor DNA polymerase alpha activity, with the majority (60-75%) localized in soluble nucleoplasm and a significant amount (13-20%) retained in the nuclear matrix. In the host mammary gland, nuclear matrix-bound DNA polymerase alpha was highest, accounting for 48% of total nuclear activity, during late pregnancy when mammary cells undergo rapid raplication. During lactation, when cells in mammary gland cease to divide, only 8% of enzyme activity was in the nuclear matrix, while the majority (60-80%) of DNA polymerase alpha activity was localized in nucleoplasm. In both R3230AC tumor and mammary gland regardless of host's lactational status, the majority (60-80%) of DNA polymerase beta activity was localized in the high salt-soluble chromatin. These present data thus suggest that, regardless of host lactational status, R3230AC tumor has many cycling cells, each with a large pool of DNA polymerase alpha molecules maintaining maximal and constant replicative activity, while normal mammary gland cells have a smaller pool of DNA polymerase alpha which become primarily matrix-bound only during active cell replication during late pregnancy. A constant localization of nuclear DNA polymerase beta in chromatin in both mammary gland and the tumor suggest it is not important in mammary cell proliferation.


Assuntos
Adenocarcinoma/enzimologia , Núcleo Celular/enzimologia , DNA Polimerase II/metabolismo , Lactação/fisiologia , Neoplasias Mamárias Experimentais/enzimologia , Animais , DNA Polimerase I/metabolismo , DNA de Neoplasias/metabolismo , Feminino , Transplante de Neoplasias , Gravidez , Ratos , Ratos Endogâmicos F344
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