siRNA沉默整合素beta1 基因对子宫内膜癌细胞侵袭、转移的影响

目的：探讨siRNA 沉默整合素茁1 基因对子宫内膜癌细胞侵袭、转移的影响。方法：选取子宫内膜癌ECC-1细胞系(ER阳性) 和KLE细胞系(ER阴性)，分别转染Integrin beta1 siRNA 质粒(Integrin beta1 siRNA 组)、无义序列siRNA质粒(无义序列对照组)和空载 质粒(空载对照组)，利用实时荧光定量PCR 检测各组细胞中Integrin 茁1 mRNA的表达，Western blot 检测各组细胞中Integrin beta1、 beta-catenin 和C-Myc 蛋白的表达，Transwell 小室检测各组细胞迁移和侵袭能力，MTT 法检测各组细胞的增殖情况。结果：Integrin beta1 siRNA 组ECC-1 细胞和KLE 细胞中Integrin beta1 mRNA 和蛋白相对表达量均低于无义序列对照组和空载对照组(P<0.05)； Integrin beta 1 siRNA组ECC-1 细胞和KLE细胞中beta-catenin 蛋白和C-Myc 蛋白相对表达量均低于无义序列对照组和空载对照组， 差异均有统计学意义(P<0.05)；Integrin beta1 siRNA组ECC-1 细胞和KLE 细胞中迁移细胞数和侵袭细胞数均低于无义序列对照组 和空载对照组(P<0.05)；Integrin beta1 siRNA 组ECC-1细胞和KLE 细胞的A 值均低于无义序列对照组和空载对照组(P<0.05)。结 论：特异性抑制Integrin beta1 基因可抑制子宫内膜癌细胞迁移、侵袭和增殖，可能与抑制Wnt信号传导有关。     

Development and use of striped bass-specific RFLP probes

We sought to develop nuclear DNA (nDNA) probes which could be used to complement mtDNA and DNA fingerprinting markers in distinguishing striped bass, Morone saxatilis (Walbaum), from discrete spawning systems. Restriction endonuclease-generated single copy, 10–20-kb striped bass nuclear nDNA fragments were cloned into the bacteriophage vector Lambda Dash II and tested in Southern blot analyses for their abilities to reveal population-specific polymorphisms. Three of the I7 nDNA sequences tested exhibited polymorphisms which potentially could be used to delineate striped bass populations. One probe, DSB 22, revealed significant genotypic frequency differences between Gulf of Mexico and Atlantic striped bass and among striped bass representative of some Atlantic systems. These preliminary results suggest that single copy nDNA sequences may provide sufficient polymorphisms to aid in stock identification of species which proved genetically monomorphic using other approaches.     

The Effects of Mobile Phone Radiofrequency Radiation on Cochlear Stria Marginal Cells in Sprague–Dawley Rats

To investigate the possible mechanisms for biological effects of 1,800 MHz mobile radiofrequency radiation (RFR), the radiation-specific absorption rate was applied at 2 and 4 W/kg, and the exposure mode was 5 min on and 10 min off (conversation mode). Exposure time was 24 h short-term exposure. Following exposure, to detect cell DNA damage, cell apoptosis, and reactive oxygen species (ROS) generation, the Comet assay test, flow cytometry, DAPI (4′,6-diamidino-2-phenylindole dihydrochloride) staining, and a fluorescent probe were used, respectively. Our experiments revealed that mobile phone RFR did not cause DNA damage in marginal cells, and the rate of cell apoptosis did not increase (P > 0.05). However, the production of ROS in the 4 W/kg exposure group was greater than that in the control group (P < 0.05). In conclusion, these results suggest that mobile phone energy was insufficient to cause cell DNA damage and cell apoptosis following short-term exposure, but the cumulative effect of mobile phone radiation still requires further confirmation. Activation of the ROS system plays a significant role in the biological effects of RFR. Bioelectromagnetics. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.     

Identification of the Active Sites in the Methyltransferases of a Transcribing dsRNA Virus

Many double-stranded RNA (dsRNA) viruses are capable of transcribing and capping RNA within a stable icosahedral viral capsid. The turret of turreted dsRNA viruses belonging to the family Reoviridae is formed by five copies of the turret protein, which contains domains with both 7-N-methyltransferase and 2′-O-methyltransferase activities, and serves to catalyze the methylation reactions during RNA capping. Cypovirus of the family Reoviridae provides a good model system for studying the methylation reactions in dsRNA viruses. Here, we present the structure of a transcribing cypovirus to a resolution of ~ 3.8 Å by cryo-electron microscopy. The binding sites for both S-adenosyl-l-methionine and RNA in the two methyltransferases of the turret were identified. Structural analysis of the turret in complex with RNA revealed a pathway through which the RNA molecule reaches the active sites of the two methyltransferases before it is released into the cytoplasm. The pathway shows that RNA capping reactions occur in the active sites of different turret protein monomers, suggesting that RNA capping requires concerted efforts by at least three turret protein monomers. Thus, the turret structure provides novel insights into the precise mechanisms of RNA methylation.