RESUMEN
<p><b>OBJECTIVE</b>To study the genotype and gene characterization of measles wild viruses circulated in Jilin provinces, and to provide scientific evidences for setting down controlling and preventing strategy and measures.</p><p><b>METHODS</b>38 strains of measles virus isolated in 2001-2006 were genotyped by RT-PCR-RFLP, some strains of measles virus in Jilin province were chosen for the phylogenetic analysis and for the homology analysis of nucleotide and amino acid sequences.</p><p><b>RESULTS</b>All the 38 strains of measles virus were identified as H1 genotype by RT-PCR-RFLP, and 29 strains of them were identified further as H1 a by sequence analysis. The homology of nucleotide was 88.0%-89.4% and the homology of amino acid was 91.8%-92.7% .The average diversity was less than 1.4%.</p><p><b>CONCLUSION</b>The measles virus of H1a genotype was the circulating virus within recent years in Jilin province. There were the same measles virus strains circulating and transmitting at different years and also the different H1a measles virus strains co-circulating at the same year. There were the same transmission chain caused by the same measles virus with other provinces.</p>
Asunto(s)
Humanos , China , Epidemiología , Genotipo , Sarampión , Epidemiología , Virología , Virus del Sarampión , Clasificación , Genética , Epidemiología Molecular , Filogenia , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , MétodosRESUMEN
<p><b>OBJECTIVE</b>To investigate the expression of ER alpha in chemically induced, ER alpha-negative human breast cancer MDA-MB-435 cells and its restoration of the responsiveness to endocrine therapy.</p><p><b>METHODS</b>MDA-MB-435 cells were treated with HDAC inhibitor trichostatin A(TSA)and DNMT1 inhibitor 5-AZA-CdR (AZA). The mRNA level of ER alpha, PR and PS2 in treated MDA-MB-435 cells was detected by RT-PCR. The WST-8 (water-soluble tetrazolium salt-8) method was used to analyze the proliferation rate of the cells. Xenograft in female nude mice was used to further explore the change of proliferation rate of treated MDA-MB-435 cells in vivo.</p><p><b>RESULTS</b>After treatment with AZA and TSA, mRNA expression of ER alpha, PR and pS2 was up-regulated in MDA-MB-435 cells. The mRNA level of ER alpha was the hightest when MDA-MB-435 cells were treated with 2.5 micromol/L AZA and 100 ng/ml TSA. The treated MDA-MB-435 cells showed different proliferation rate in various media containing different concentration of estrodial. The MDA-MB-435 cells showed down-regulated proliferation rate after treatment with the combination of 2.5 micromol/L AZA and 100 ng/ml TSA, and 4-OH tamoxifen could suppress the growth rate of the induced MD-MBA-435 cells but not the untreated cells. The treated MDA-MB-435 cells showed slower proliferation rate than that of untreated cells in vivo (P <0. 01), and the proliferation rate of the treated MDA-MB-435 cells became lower when the nude mice were deprived of estrogen by castration (P <0. 01).</p><p><b>CONCLUSION</b>After treatment with TSA and AZA, ER alpha-negative MDA-MB-435 cells can express functional ER alpha and regain responsiveness to estrogen both in vitro and in vivo. HDAC inhibitor and DNMT1 inhibitor may play an important role in restoration of sensitivity of ER alpha-negative breast cancers to endocrine therapy.</p>
Asunto(s)
Animales , Femenino , Humanos , Ratones , Azacitidina , Farmacología , Neoplasias de la Mama , Genética , Patología , Línea Celular Tumoral , Proliferación Celular , Metilasas de Modificación del ADN , Inhibidores Enzimáticos , Farmacología , Receptor alfa de Estrógeno , Genética , Regulación Neoplásica de la Expresión Génica , Inhibidores de Histona Desacetilasas , Ácidos Hidroxámicos , Farmacología , Neoplasias Mamarias Experimentales , Genética , Patología , Ratones Endogámicos BALB C , Ratones Desnudos , Ovariectomía , ARN Mensajero , Genética , Receptores de Progesterona , Genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor Trefoil-1 , Proteínas Supresoras de Tumor , Genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
<p><b>OBJECTIVE</b>To explore the effects of mifepristone on the growth of human gastric cancer cell line MKN-45 and its possible mechanisms.</p><p><b>METHODS</b>In situ hybridization was used to detect the expression of progesterone receptor (PR) mRNA in MKN-45 cells. Proliferation, cell cycle distribution, and the expression of Bcl-xL and vascular endothelial growth factor (VEGF) of MKN-45 cells incubated with various concentrations of mifepristone (1, 5, 10, and 20 micromol/L) were analyzed using MTT reduction assay, flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR), and enzyme-linked immunoabsorbent assay (ELISA), respectively. After transplantation of MKN-45 cells underneath the skin of athymic mice, mifepristone was administrated with the dose of 50 mg/(kg x d) for 6 weeks to evaluate the tumor growth. Apoptosis and the expression of proliferating cell nuclear antigen (PCNA) in xenografted tumors were detected using transmission electron microscopy and immunohistochemical staining, respectively.</p><p><b>RESULTS</b>PR mRNA was highly expressed in cultured MKN-45 cell. Mifepristone dose-dependently inhibited the proliferation of MKN-45 cells, and the inhibitory rate was dramatically increased from 7.21% to 47.23%. The inhibitory effect was accompanied by a dose-dependent increase in the percentage of cells in G0/G1 phase, and with a concurrent decrease in the proportion of S- and G2M-phase cells and the proliferative index from 57.65% to 24.54%. Meanwhile, mifepristone down-regulated the expression of Bcl-xL and VEGF in a dose-dependent manner. In vivo, mifepristone effectively inhibited the growth of xenografted tumors in nude mice (55.14% for inhibitory rate), induced apoptosis, and down-regulated PCNA expression in gastric cancer.</p><p><b>CONCLUSION</b>Mifepristone exerts significant growth inhibitory effects on PR-positive human MKN-45 gastric cancer cells via multiple mechanisms, and may be a beneficial agent against the tumor.</p>