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1.
Biomedical and Environmental Sciences ; (12): 419-426, 2019.
Artigo em Inglês | WPRIM | ID: wpr-773388

RESUMO

OBJECTIVE@#Silicosis, caused by inhalation of silica dust, is the most serious occupational disease in China and the aim of present study was to explore the protective effect of Ang (1-7) on silicotic fibrosis and myofibroblast differentiation induced by Ang II.@*METHODS@#HOPE-MED 8050 exposure control apparatus was used to establish the rat silicosis model. Pathological changes and collagen deposition of the lung tissue were examined by H.E. and VG staining, respectively. The localizations of ACE2 and α-smooth muscle actin (α-SMA) in the lung were detected by immunohistochemistry. Expression levels of collagen type I, α-SMA, ACE2, and Mas in the lung tissue and fibroblasts were examined by western blot. Levels of ACE2, Ang (1-7), and Ang II in serum were determined by ELISA. Co-localization of ACE2 and α-SMA in fibroblasts was detected by immunofluorescence.@*RESULTS@#Ang (1-7) induced pathological changes and enhanced collagen deposition in vivo. Ang (1-7) decreased the expressions of collagen type I and α-SMA and increased the expressions of ACE2 and Mas in the silicotic rat lung tissue and fibroblasts stimulated by Ang II. Ang (1-7) increased the levels of ACE2 and Ang (1-7) and decreased the level of Ang II in silicotic rat serum. A779 enhanced the protective effect of Ang (1-7) in fibroblasts stimulated by Ang II.@*CONCLUSION@#Ang (1-7) exerted protective effect on silicotic fibrosis and myofibroblast differentiation induced by Ang II by regulating ACE2-Ang (1-7)-Mas axis.


Assuntos
Animais , Actinas , Metabolismo , Angiotensina I , Sangue , Farmacologia , Usos Terapêuticos , Angiotensina II , Sangue , Animais Recém-Nascidos , Diferenciação Celular , Células Cultivadas , Colágeno Tipo I , Metabolismo , Modelos Animais de Doenças , Pulmão , Metabolismo , Patologia , Miofibroblastos , Fragmentos de Peptídeos , Sangue , Farmacologia , Usos Terapêuticos , Peptidil Dipeptidase A , Metabolismo , Ratos Wistar , Silicose , Metabolismo , Patologia
2.
Chinese Medical Journal ; (24): 4037-4043, 2012.
Artigo em Inglês | WPRIM | ID: wpr-339904

RESUMO

<p><b>BACKGROUND</b>Sterol regulatory element binding protein (SREBP)-2 plays a key role in lipid homeostasis by stimulating gene expression of cholesterol biosynthetic pathways. The insulin-like growth factor binding protein (IGFBP) family regulates growth and metabolism, especially bone cell metabolism, and correlates with osteonecrosis. However, association of their gene polymorphisms with risk of avascular necrosis of the femoral head (ANFH) has rarely been reported. We determined whether SREBP-2 and IGFBP-3 gene polymorphisms were associated with increased ANFH risk in the Chinese population.</p><p><b>METHODS</b>Two single nucleotide polymorphisms of SREBP2 gene, rs2267439 and rs2267443, and one of IGFBP-3 gene, rs2453839, were selected and genotyped in 49 ANFH patients and 42 control individuals by direct sequencing assay.</p><p><b>RESULTS</b>The frequencies of rs2267439 TT and rs2267443 GA of SREBP2 and rs2453839 TT and CT of IGFBP-3 in the ANFH group showed increased and decreased tendencies (against normal control group), respectively. Interaction analysis of genes revealed that the frequency of carrying rs2267439 TT and rs2267443 GA genotypes of SREBF-2 in ANFH patients was significantly higher than in the control group (P < 0.05). Association analysis between polymorphisms and clinical phenotype demonstrated that the disease course in ANFH patients with the rs2453839 TT genotype of IGFBP-3 was significantly shorter than that of CT + CC carriers (P < 0.01). CT + CC genotype frequency in patients with stage III/IV bilateral hip lesions was significantly higher than in those with stage III/IV unilateral lesions and stage II/III bilateral lesions (P < 0.05 - 0.02).</p><p><b>CONCLUSIONS</b>Our results suggested that interaction of SREBP-2 gene polymorphisms and the relationship between the polymorphisms and clinical phenotype of IGFBP-3 were closely related to increased ANFH risk in the Chinese population. The most significant finding was that the CT + CC genotype carriers of IGFBP-3 rs2453839 were highly associated with the development of ANFH.</p>


Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Povo Asiático , Genética , Necrose da Cabeça do Fêmur , Genética , Predisposição Genética para Doença , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina , Genética , Reação em Cadeia da Polimerase , Polimorfismo Genético , Genética , Proteína de Ligação a Elemento Regulador de Esterol 2 , Genética
3.
Chinese Journal of Pediatrics ; (12): 771-776, 2012.
Artigo em Chinês | WPRIM | ID: wpr-348540

RESUMO

<p><b>OBJECTIVE</b>To study the cognitive function, its correlation with and the impact on quality of life in epileptic children aged 6-13 years in regular school.</p><p><b>METHOD</b>Cognitive function of 172 children with various types of epilepsy were measured using a computerized neuropsychological test battery including six items. Their scores across the neuropsychological measures were compared with 172 healthy control subjects from the general population strictly matched for age, sex and the region where education was accepted. The quality of life was measured in 105 cases by the Quality of Life in Epilepsy Inventory (QOLIE-31).</p><p><b>RESULT</b>(1) After adjusting for age, gender, and education, children with epilepsy performed significantly worse than healthy control subjects on 5 of 6 cognitive tasks, including Raven's progressive matrices correct number (8.6 vs. 14.0), choice reaction time (620.4 ms vs. 489.5 ms), word-rhyming tasks (2796.9 ms vs. 2324.4 ms), simple substraction correct number (28.6 vs. 35.5)as well as number comparision (1002.4 ms vs. 803.1 ms), P < 0.01. When an impairment index was calculated, 44.2% patients had at least one abnormal score on the test battery, compared with 14.5% of healthy volunteers, there was statistically significant differences between the two groups, P < 0.001. (2) Children with new onset epilepsy before the treatment with anti-epilepstic drugs performed significantly worse than healthy controls on 5 of 6 cognitive tasks, including Raven's progressive matrices correct number (9.1 vs. 13.8), choice reaction time (625.8 ms vs.474.5 ms), word-rhyming tasks(3051.8 ms vs. 2575.4 ms), simple substraction correct number (28.9 vs. 35.3) as well as number comparison (942.4 ms vs. 775.8 ms), P < 0.01. (3) Cognitive performance was not related to the age of onset, type of epilepsy, therapy duration or comorbid emotional and behavior disorders, P > 0.05. (4) 105 cases filled in the QOLIE-31 questionaire, the total score of the quality of life in the group without cognitive impairment and psychical conditions was the highest (60.5 ± 0.9), and the lowest total score was found in group with cognitive impairment and psychical conditions (54.6 ± 1.5), there were highly significant differences between the groups, P < 0.001.</p><p><b>CONCLUSION</b>Almost one-half of the children with epilepsy accepting regular education had at least one abnormal score in the battery tests. Newly diagnosed untreated patients with epilepsy are cognitively compromised before the start of antiepileptic drug medication. Cognitive impairment was not related to the epilepsy-related or psychiatric variables. Cognitive impairment and mental disorders require further attention and essential therapy, which is important to the improvement of the quality of life in epileptic children.</p>


Assuntos
Adolescente , Criança , Feminino , Humanos , Masculino , Cognição , Fisiologia , Transtornos Cognitivos , Diagnóstico , Epidemiologia , Psicologia , Comorbidade , Epilepsia , Psicologia , Testes Neuropsicológicos , Qualidade de Vida , Tempo de Reação , Inquéritos e Questionários
4.
Chinese Medical Journal ; (24): 2888-2894, 2010.
Artigo em Inglês | WPRIM | ID: wpr-237396

RESUMO

<p><b>BACKGROUND</b>Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital heart anomaly. We aimed to illustrate the clinical features and long-term prognosis of patients with ALCAPA.</p><p><b>METHODS</b>Twenty three patients (13 males and 10 females, ages ranging from 2.5 months to 65 years) identified as ALCAPA in Beijing Anzhen Hospital from April 1984 to June 2009 were divided into two groups, based on the age of onset: group 1 (≤ 12 months, n = 16) and group 2 (> 12 months, n = 7).</p><p><b>RESULTS</b>Fifty six point three percent of patients in group 1 had been misdiagnosed as endocardial fibroelastosis (9/16), 18.8% as dilated cardiomyopathy (3/16) and 6.3% as myocardial infarction (1/16). Patients in group 2 were usually diagnosed as coronary heart disease, myocarditis, or patent ductus arteriosus. Electrocardiography in group 1 revealed abnormal Q waves with T wave inversion in leads I, avL, V(4)-V(6), especially in lead avL (deep and wide Q wave); but no specific manifestations in group 2. A higher percentage of patients in group 1 had cardiomegaly on chest radiograph (86.7% vs. 33.3%, P = 0.031), while pulmonary artery protrusion was more common in group 2 (26.7% vs. 83.3%, P = 0.046). Lower left ventricular ejection fraction (LVEF) was present in group 1 than in group 2 ((48.5 ± 11.5)% vs. (65.0 ± 6.1)%, P < 0.001). Apical ventricular aneurysm (62.5% vs. 0%, P = 0.007), enhanced echogenicity of papillary muscles (87.5% vs. 28.6%, P = 0.011) and endocardial thickening (93.8% vs. 14.3%, P < 0.001) were more frequent in group 1 than in group 2. The ratio of the proximal right coronary artery (RCA) diameter to the aortic root diameter exceeded 0.14 in all cases, more prominent in group 2 (0.26 ± 0.05 vs. 0.33 ± 0.03, P = 0.009). Increased coronary artery collaterals within the interventricular septum were detected in 18 patients (78.3%) by Doppler imaging. Twenty one patients underwent cardiac surgery, including left coronary artery (LCA) ligation (1/21), LCA ligation plus coronary artery bypass grafting (1/21), Takeuchi operation (7/21), and LCA reimplantation surgery (12/21). Four patients underwent concomitant mitral valve repair and one received mitral valve replacement. Aneurysm resection was performed in 3 cases. Six patients died in hospital after surgery, and the rest of the cohort had no overt symptoms during a follow-up period of 6 to 166 months. Their abnormal Q waves gradually regressed or disappeared, and the LVEF and left ventricle size returned to normal range with alleviation of mitral insufficiency.</p><p><b>CONCLUSIONS</b>The accurate diagnosis of ALCAPA can be made with serial diagnostic methods. ALCAPA can be successfully treated with several types of cardiac surgery, and surgeries of establishing two-coronary-artery circulation are the preferred operations nowadays, with good long-term prognosis.</p>


Assuntos
Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Anomalias dos Vasos Coronários , Diagnóstico , Mortalidade , Ecocardiografia , Eletrocardiografia , Seguimentos , Prognóstico , Artéria Pulmonar , Anormalidades Congênitas
5.
Chinese Journal of Pediatrics ; (12): 346-350, 2010.
Artigo em Chinês | WPRIM | ID: wpr-245399

RESUMO

<p><b>OBJECTIVE</b>To find out the rate of comorbidities of depression, anxiety disorder and attention deficit hyperactivity disorder (ADHD) symptoms in children with epilepsy and to analyze the relevant affecting factors and impacts on quality of life.</p><p><b>METHOD</b>Totally 142 children with various types of epilepsy underwent neuropsychological assessment with the Depression Self-rating Scale for Children, the Screen for Child Anxiety Related Emotional Disorders and the ADHD Rating Scale-IV, an 18-item parent-rated questionnaire based on the diagnostic criteria for ADHD, the quality of life was measured in 100 cases on antiepileptic medications by the Quality of Life in Epilepsy Inventory (QOLIE-31). The comorbidity rates were calculated using t-test, chi(2) test and multiple logistic analysis, the variables associated with psychiatric comorbidities were determined, and the impact on quality of life was analyzed.</p><p><b>RESULT</b>(1) The total rate of emotional and behavioral comorbidities was 57.7% (82/142), the frequency of depressive disorder, anxiety disorder and ADHD was 14.8%, 44.4% and 17.6%, respectively. The suicidal ideation occasionally occurred in 5.6% of the cases and 0.7% of cases often had the ideation, but no suicidal action was found in any case. (2) Risk factors for the emotional and behavioral disorders: multiple logistic analysis indicated that age, gender and epilepsy illness-related variables were not relative to the comorbidities, P > 0.05, there were interactions among the disorders. (3) The impact on the quality of life: The emotional and behavioral conditions were associated with the low quality of life, which was significantly lower in epileptic children with co-morbid disorder compared to non-comorbidities epilepsy group. Especially negative impact on the total score of quality of life and four sub-items such as overall quality, emotional well-being, cognitive and social function, P < 0.001. There were also significant differences between the two groups in the other three sub-items including fear for seizure attack, energy/fatigue and medication effects (P < 0.05).</p><p><b>CONCLUSIONS</b>The frequency of emotional and behavioral disorders including depress disorder, anxiety disorder and ADHD was considerably high in children with epilepsy. Age, gender and epilepsy illness-related variables are not associated with the emotional and behavioral comorbidities, which interfere with each other. Emotional and behavioral disorder is one of the negative factors to the quality of life in epileptic patients. Neuropsychological assessment and treatment are important for improvement of the quality of life in children with epilepsy.</p>


Assuntos
Criança , Feminino , Humanos , Transtorno do Deficit de Atenção com Hiperatividade , Epidemiologia , Transtornos do Comportamento Infantil , Epidemiologia , Patologia , Comorbidade , Emoções , Epilepsia , Epidemiologia , Psicologia , Qualidade de Vida , Inquéritos e Questionários
6.
West China Journal of Stomatology ; (6): 312-319, 2008.
Artigo em Chinês | WPRIM | ID: wpr-264430

RESUMO

<p><b>OBJECTIVE</b>To study the effect and mechanism of salidroside on salivary adenoid cystic carcinoma (SACC-2) cells in vitro.</p><p><b>METHODS</b>To detect the effect of salidroside on SACC-2 cells growth with CCK-8 kit, the growth curve of cells were drawn. To detect the expression of cysteine proteinase (Caspase 3 and Caspase 8) and proliferating cell nuclear antigen (PCNA) in SACC-2 cells, immunohistochemistry staining was used.</p><p><b>RESULTS</b>According the results of CCK-8 kit detected, salidroside could inhibit the proliferation of SACC-2 cells, IC50 value was (4.99+/-0.23) microg/mL. Growing curve showed that SACC-2 cells of salidroside groups decreased with extending cell culture time. Immunohistochemistry staining showed that Caspase 3 and Caspase 8 were both strong positive expression in SACC-2 cells of salidroside groups, and poor positive expression in SACC-2 cells of control group, the difference was significant (P<0.01). The expression of PCNA was reverse (P<0.01).</p><p><b>CONCLUSION</b>Salidroside could inhibit the proliferation of SACC-2 cells and induce SACC-2 cell apoptosis in vitro, which could be a kind of antitumor medicine in the future.</p>


Assuntos
Humanos , Apoptose , Carcinoma Adenoide Cístico , Linhagem Celular Tumoral , Proliferação de Células , Glucosídeos , Imuno-Histoquímica , Técnicas In Vitro , Fenóis , Neoplasias das Glândulas Salivares
7.
Chinese Journal of Hematology ; (12): 383-387, 2007.
Artigo em Chinês | WPRIM | ID: wpr-328336

RESUMO

<p><b>OBJECTIVE</b>To explore the role of reversal multidrug resistance (MDR) using short hairpin RNA (shRNA) expression vectors in multidrug resistance human leukemia cell line K562/ADM.</p><p><b>METHODS</b>The oligonucleotides with 19-mer hairpin structure were synthesized. The shRNA expression vectors were constructed and introduced into K562/ADM cells. Expression of mdr1 mRNA was assessed by RT-PCR, and P-gp expression was determined by Western blot. The apoptosis and sensitivity of the K562/ADM cells to doxorubicin were quantified by flow cytometry and methyl thiazolyl tetrazolium (MTT) assays, respectively. Cellular daunorubicin accumulation was assayed by laser confocal scanning microscope (LCSM).</p><p><b>RESULTS</b>In positive clones of K562/ADM cells stably transfected with pSilencer 3.1-HI neo mdr1-A and mdr1-B shRNA expression vectors, RT-PCR showed that mdr1 mRNA expression was significantly reduced to 35.9% (P < 0.05), 27.5% (P < 0.01), respectively. Western blot showed that P-gp expression was significantly and specifically inhibited. Resistance against doxorubicin was decreased from 79-fold to 38-fold (P < 0.05), 30-fold (P < 0.01) respectively. Furthermore, the fluorescence intensity of K562/ADM cells was increased significantly compared with the control. shRNA vectors significantly enhanced the cellular daunorubicin accumulation. The percent of the apoptosis cell was significantly enhanced to 18.1% (P < 0.05) , 54.4% (P < 0.01) respectively.</p><p><b>CONCLUSIONS</b>shRNA expression vectors can effectively reverse MDR, and restore the sensitivity of drug-resistance K562/ADM cells to conventional chemotherapeutic agents.</p>


Assuntos
Humanos , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Genética , Metabolismo , Apoptose , Doxorrubicina , Farmacologia , Resistência a Múltiplos Medicamentos , Genética , Resistencia a Medicamentos Antineoplásicos , Genética , Vetores Genéticos , Células K562 , Interferência de RNA , RNA Mensageiro , Genética , Transfecção
8.
Chinese Medical Journal ; (24): 905-910, 2006.
Artigo em Inglês | WPRIM | ID: wpr-265281

RESUMO

<p><b>BACKGROUND</b>The hematopoietic microenvironment (HM) plays a critical role in malignant cell growth, patient survival, and response to chemotherapy in hematologic malignancies. However, mechanisms associated with this environmental influence remain unclear. In this study, we investigated the role of bone marrow derived mesenchymal stem cells (MSCs) in U937 cell line, to find out the relations between leukemia drug resistance and the MSCs.</p><p><b>METHODS</b>U937 cells were cultured in suspension or grew adherently with MSCs. The cell growth curve was drawn and the cell cycle was measured by flow cytometry. Apoptosis and sensitivity of U937 to daunoblastina (DNR) were quantified by DNA ladder detection and trypan blue exclusion assays, respectively. The gene expression profile chip technology was used to determine and analyze the changes in apoptosis-related gene expression after adherent culture and the expression of MDR1 mRNA was assessed by reverse transcriptional polymerase chain reaction (RT-PCR) at the same time.</p><p><b>RESULTS</b>In the adherent culture, the proliferation of the U937 cells was inhibited, the G0/G1 phase cells increased (F = 64.9726, P < 0.0001), G2/M phase cells were decreased (F = 98.1361, P < 0.0001) and the natural apoptosis rate was decreased (F = 24.0866, P < 0.0001) compared with those in the suspended culture. U937 cell viability was enhanced and cell apoptosis was blocked during DNR treatment in adherent culture with MSCs. Thirty-nine differently expressed genes were screened from the 487 apoptosis related genes in the adherent culture U937 cells. Among the 37 upregulated genes, Bcl-XL was upregulated most significantly. Two genes were downregulated. Adherent culture did not induce MDR1 mRNA expression in U937 cells.</p><p><b>CONCLUSIONS</b>MSCs play a role in modulating the proliferation of U937 cells and response of U937 cells to DNR, and Bcl-XL apoptosis-inhibiting gene may be most important in determining the sensitivity of leukemic cells to treatment, which is not related to MDR1.</p>


Assuntos
Humanos , Apoptose , Células da Medula Óssea , Fisiologia , Proliferação de Células , Daunorrubicina , Farmacologia , Resistencia a Medicamentos Antineoplásicos , Genes MDR , Imunofenotipagem , Células-Tronco Mesenquimais , Fisiologia , Células U937
9.
Journal of Experimental Hematology ; (6): 308-312, 2006.
Artigo em Chinês | WPRIM | ID: wpr-280677

RESUMO

This study was aimed to compare K562 cell proliferation, chemo-sensitivity and alteration of MDR1 before and after adhesive culture with MSC, so as to evaluate the relationship between chemodrug-resistance of leukemia cells and hemopoietic microenvironment. K562 cell cultivated in suspension and adhesively cultivated with MSC were collected respectively and cell proliferation curves were drawn; the cell cycle was determined by flow cytometry; the effect of chemotherapy on cellular viability and apoptosis of K562 cell was investigated, the MDR1 gene expression was determined by RT-PCR. The results showed that K562 cells adhesively cultivated with MSC were inhibited and cells in G0/G1 increased (P < 0.05), cells in S phase decreased (P < 0.05) and those in G0/G1 increased (P < 0.01), compared with that cultivated in suspension. In process of daunomycin-inducing apoptosis, K562 cell apoptosis in the adhesive culture with MSC was inhibited (P < 0.05). MDR1 gene expression in K562 cells was not induced or altered by adhesive co-cultivation. It is concluded that by co-culture of cell-cell contact with MSC, growth suppression and induction of chemo-resistance of K562 cells take place. The mechanism, however, seems not relevant with MDR1.


Assuntos
Humanos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Genética , Apoptose , Fisiologia , Células da Medula Óssea , Biologia Celular , Proliferação de Células , Células Cultivadas , Técnicas de Cocultura , Daunorrubicina , Farmacologia , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Células K562 , Células-Tronco Mesenquimais , Biologia Celular
10.
Chinese Journal of Hematology ; (12): 249-253, 2006.
Artigo em Chinês | WPRIM | ID: wpr-243964

RESUMO

<p><b>OBJECTIVE</b>To compare apoptosis gene expression profiling of U937 cells in suspension culture with that cultivated with mesenchymal stem cells (MSCs), and find out the relationship between drug resistance of leukemia cells and hemopoietic microenvironment.</p><p><b>METHODS</b>U937 cells were cultivated in adhesion culture with MSCs and in suspension culture for 48 hours. Cell cycle was determined by flow cytometry and gene expression profiling by cDNA microarray.</p><p><b>RESULTS</b>Compared with that in suspension, G(0)/G(1) fraction of U937 cells increased in adhesion culture (45.3 +/- 3.1)% vs (32.6 +/- 2.1)%, respectively (P < 0.05), whereas G(2)/M fraction and apoptosis rate were decreased. After 48 h twenty-eight differential expression genes were screened out in 487 apoptosis-related genes, among which 27 were up-regulated and were mainly apoptosis-suppressor genes, apoptosis-promoter genes, cell cycle positive control genes and cell cycle negative control genes. But Bcl-XL was up-regulated most obviously. The only one gene down-regulated was an apoptosis promoter gene.</p><p><b>CONCLUSION</b>Adhesion culture with MSCs can lead to growth suppression and decrease natural apoptosis of U937 cells. The mechanism was multiple gene effects, but Bcl-XL may be of the most importance.</p>


Assuntos
Humanos , Apoptose , Genética , Adesão Celular , Ciclo Celular , Genética , Células Cultivadas , Técnicas de Cocultura , Citometria de Fluxo , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Linfoma Difuso de Grandes Células B , Genética , Patologia , Células-Tronco Mesenquimais , Biologia Celular , Metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Células U937
11.
Chinese Medical Journal ; (24): 893-902, 2005.
Artigo em Inglês | WPRIM | ID: wpr-288328

RESUMO

<p><b>BACKGROUND</b>RNA interference using short hairpin RNA (shRNA) can mediate sequence-specific inhibition of gene expression in mammalian cells. A vector-based approach for synthesizing shRNA has been developed recently. Overexpression of P-glycoprotein (P-gp), the MDR1 gene product, confers multidrug resistance (MDR) to cancer cells. In this study, we reversed MDR using shRNA expression vectors in a multidrug-resistant human breast cancer cell line (MCF-7/AdrR).</p><p><b>METHODS</b>The two shRNA expression vectors were constructed and introduced into MCF-7/AdrR cells. Expression of MDR1 mRNA was assessed by RT-PCR, and P-gp expression was determined by Western Blot and immunocytochemistry. Apoptosis and sensitization of the breast cancer cells to doxorubicin were quantified by flow cytometry and methyl thiazolyl tetrazolium (MTT) assays, respectively. Cellular daunorubicin accumulation was assayed by laser confocal scanning microscopy (LCSM). Statistical significance of differences in mean values was evaluated by Student's t tests. P < 0.05 was considered statistically significant.</p><p><b>RESULTS</b>In MCF-7/AdrA cells transfected with MDR1-A and MDR1-B shRNA expression vectors, RT-PCR showed that MDR1 mRNA expression was reduced by 40.9% (P < 0.05), 30.1% (P < 0.01) (transient transfection) and 37.6% (P < 0.05), 28.0% (P < 0.01) (stable transfection), respectively. Western Blot and immunocytochemistry showed that P-gp expression was significantly and specifically inhibited. Resistance against doxorubicin was decreased from 162-fold to 109-fold (P < 0.05), 54-fold (P < 0.01) (transient transfection) and to 108-fold (P < 0.05), 50-fold (P < 0.01) (stable transfection). Furthermore, shRNA vectors significantly enhanced the cellular daunorubicin accumulation. The combination of shRNA vectors and doxorubicin significantly induced apoptosis in MCF-7/AdrR cells.</p><p><b>CONCLUSIONS</b>shRNA expression vectors effectively reduce MDR expression in a sustained fashion and can restore the sensitivity of drug-resistant cancer cells to conventional chemotherapeutic agents.</p>


Assuntos
Humanos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular , Daunorrubicina , Farmacocinética , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Citometria de Fluxo , Genes MDR , Vetores Genéticos , Interferência de RNA , RNA Interferente Pequeno , Genética , Transfecção
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