Human interleukin-1 beta gene

We report the nucleotide sequence of the human chromosomal gene which encodes the interleukin-1 beta protein (IL-1 beta). The gene spans a region of 7.5 kb and the coding part is divided into seven exons. Comparison with the homologous mouse gene reveals that the structural organization is conserved through evolution. In addition to this, human and murine IL-1 beta genes show extensive sequence homology within the intervening sequences.     

OVCA1: tumor suppressor gene

OVCA1, also known as DPH2L1, is a tumor suppressor gene associated with ovarian carcinoma and other tumors. Ovca1 homozygous mutant mice die at birth with developmental delay and cell-autonomous proliferation defects. Ovca1 heterozygous mutant mice are tumor-prone but rarely develop ovarian tumors. OVCA1 appears to be the homolog of yeast DPH2, which participates in the first biosynthetic step of diphthamide, by modification of histidine on translation elongation factor 2 (EF-2). Yeast dph2 mutants are resistant to diphtheria toxin, which catalyses ADP ribosylation of EF-2 at diphthamide. Thus, there appears to be growing evidence implicating alterations in protein translation with tumorigenesis.     

L1 retrotransposon-mediated stable gene silencing

RNA interference (RNAi) is widely used for functional studies and has been proposed as a potential therapeutic agent. Current RNAi systems are largely efficient, but have limitations including transient effect, the need for viral handling and potential insertional mutations. Here, we describe a simple L1 retrotransposon-based system for the delivery of small interfering RNA (siRNA) and stable silencing in human cells. This system demonstrated long-term siRNA expression and significant reduction in both exogenous and endogenous gene expression by up to 90%. Further characterization indicated that retrotransposition occurred in a controlled manner such that essentially only one RNAi-cassette was integrated into the host genome and was sufficient for strong interference. Our system provides a novel strategy for stable gene silencing that is easy and efficient, and it may have potential applications for ex vivo and in vivo molecular therapy.     

视网膜母细胞瘤基因1(RB1)研究进展

视网膜母细胞瘤基因1(Retinoblastoma1,RB1)是人类第一个分离克隆的抑癌基因。RB1基因是细胞周期的负调控因子,通过与转录因子结合调节细胞增殖和分化所需基因的表达,从而维持细胞生长发育的平衡。因此,该基因的功能与细胞周期、细胞衰老、细胞凋亡、细胞分化和生长抑制等有关。文章对RB1基因的结构、表达及其功能的研究进展进行了综述。