Development of an in vitro clonogenic assay for the R3327 rat prostatic adenocarcinoma permits comparison of the proliferative potential of the R3327, R3327A,and R3327AT tumors

The R3327 class of rat prostate tumors consists of both the androgen-dependent R3327 adenocarcinoma and androgen-independent sublines, the R3327At spindle cell tumor, and the R3327A, a squamous cell carcinoma. We have developed in vitro clonogenic cell assays to measure and compare systematically the proliferative potential of these tumors following various monodispersion techniques. Linear relationships between the number of monodispersed tumor cells cultured at low cell density and the number of colonies formed 10 days later establish these assays as the first quantitative cellular approach to those proliferative subpopulations ultimately responsible for the growth of these tumors. We have chosen the name colony forming cell-prostatic adenocarcinoma (CFC-PA) to refer to the members of the proliferative subpopulation of the R3327 tumor. An ultrastructurd comparison of R3327 adenocarcinoma tissue sections with the cells produced during culture provides evidence that the cells of the proliferative subpopulation may be derived from the acinar epithelium of the tumor.     

白藜芦醇诱导K562／AO2凋亡与mdr1基因表达的关系

目的研究白藜芦醇（Res）体外对K562／AO2增殖及凋亡的影响，并探讨与耐药基因mdr1表达的关系。方法用噻唑蓝比色法（MTT）检测对照组、不同剂量Res组（25～200μmol／L）作用48h后K562／AO2增殖率，用流式细胞仪检测各组凋亡率，并用逆转录-聚合链反应（RT—PCR）法检测各组mdr1 mRNA的表达。结果Res体外对人K562／AO2细胞有显著增殖抑制及凋亡诱导作用，Res组（25μmol／L、50μmol／L、100μmol／L、200μmol／L）作用48h后其凋亡率均显著高于对照组（P〈0．05）；mdr1 mRNA表达相对强度均显著低于对照组（P〈0．05），且随浓度增加而表达减弱。结论Res体外能诱导K562／AO2细胞的凋亡，且呈一定的浓度依赖性，其作用机制可能与逆转mdr1 mRNA基因表达有关。     

DNA-polymerases in neuron and glial cells of developing and aging mouse brain

DNA-polymerases α and β were studied in neuron and glial cells of mouse during developing and aging brain. Maximum activity of α-enzyme was found to be prenatal, though a very low but significant level could be detected in aging brain. Furthermore, this pattern was found to be dependent upon cell types that shift in peak activity just before birth in glial cells in contrast to neurons. DNA-polymerase-β remained high throughout the period studied though a second peak of activity was also observzd at day 30 in both cell types, suggesting a possible role in DNA-replication in addition to DNA-repair. It was found that β-enzyme from glial cells behaves differently than the same enzyme from neurons.     

白藜芦醇诱导K562/AO_2凋亡与mdr1基因表达的关系

目的研究白藜芦醇(Res)体外对K562/AO2增殖及凋亡的影响,并探讨与耐药基因mdr1表达的关系。方法用噻唑蓝比色法(MTT)检测对照组、不同剂量Res组(25~200μmol/L)作用48 h后K562/AO2增殖率,用流式细胞仪检测各组凋亡率,并用逆转录-聚合链反应(RT-PCR)法检测各组mdr1 mRNA的表达。结果Res体外对人K562/AO2细胞有显著增殖抑制及凋亡诱导作用,Res组(25μmol/L、50μmol/L、100μmol/L、200μmol/L)作用48 h后其凋亡率均显著高于对照组(P<0.05);mdr1 mRNA表达相对强度均显著低于对照组(P<0.05),且随浓度增加而表达减弱。结论Res体外能诱导K562/AO2细胞的凋亡,且呈一定的浓度依赖性,其作用机制可能与逆转mdr1 mRNA基因表达有关。