DMP-1 promoter-associated antisense strand non-coding RNA,panRNA-DMP-1, physically associates with EGFR to repress EGF-induced squamous cell carcinoma migration

Molecular and Cellular Biochemistry - Accumulating evidence suggests that specific non-coding RNAs exist in many types of malignant tissues, and are involved in cancer invasion and metastasis....     

The H19 gene: regulation and function of a non-coding RNA

The H19 gene encodes a 2.3-kb non-coding mRNA which is strongly expressed during embryogenesis. This gene belongs to an imprinted cluster, conserved on mouse chromosome 7 and human chromosome 11p15. H19 is maternally expressed and the neighbouring Igf2 gene is transcribed from the paternal allele. These two genes are co-expressed in endoderm- and mesoderm-derived tissues during embryonic development, which suggests a common mechanism of regulation. The regulatory elements (imprinted control region, CTCF insulation, different enhancer sequences, promoters of the two genes, matrix attachment regions) confer a differential chromatin architecture to the two parental alleles leading to reciprocal expression. The role of the H19 gene is unclear but different aspects have been proposed. H19 influences growth by way of a cis control on Igf2 expression. Although H19(-/-) mice are viable, a role for this gene during development has been suggested by viable H19(-/-) parthenogenetic mice. Finally it has been described as a putative tumour suppressor gene. H19 has been studied by numerous laboratories over the last fifteen years, nevertheless the function of this non-coding RNA remains to be elucidated.     

Genomic structure and domain organisation of the human Bak gene

The Bcl-2 homologue, Bak, is a potent inducer of apoptosis. FISH data presented here located the gene to 6p21.3. Mapping was consistent with its location centromeric of the HSET locus and approximately 400 kb from the MHC. The construction of a contig of genomic clones across the locus facilitated the sequencing of a PAC containing the gene. Comparison of the gene structure to functional and physical domains revealed a good agreement between the physical structure and the intron–exon organisation. The position of a single intron was conserved in comparison to other members of the Bcl-2 family, namely Bax, CED-9, Bcl-X and Bcl-2, but all other introns were displaced, consistent with a divergent phylogeny.     

Comparative analysis of antisense RNA,double-stranded RNA,and delta ribozyme-mediated gene regulation in Toxoplasma gondii

RNA tools, namely, antisense RNA, double-stranded RNA (dsRNA), and delta ribozyme, were comparatively analyzed for the development of effective RNA-based gene modulators. The gene encoding uracil phosphoribosyltransferase (UPRT) of Toxoplasma gondii was used as a target and a negative selectable marker. Using plasmid transformation and drug selection assays, we obtained T. gondii transformants resistant to 5-fluoro-2'-deoxyuridine (FDUR), the cytotoxic prodrug and substrate of UPRT, when the plasmids expressing dsRNA and active delta ribozyme were used. No resistant transformants were detected when the plasmids carrying the antisense RNA, the inactive delta ribozyme, or the chloramphenicol acetyltransferase (CAT) genes were used. Parasites generated using the plasmids expressing dsRNA and the delta ribozyme become resistant to FDUR with an LD50 of 50 +/- 5 microM and 25 +/- 8 microM, respectively. These values are approximately 25-fold and 12-fold higher than that of the RH parental parasite strain, indicating that UPRT activity of the transformed parasites was drastically inhibited. Using Northern and Southern blot analysis, we demonstrated that dsRNA and the delta ribozyme interrupt the expression of UPRT. These two RNA tools should, thus, be very useful for the study of gene expression.     

反义RNA在基因治疗中的应用

由于反义RNA作为封闭基因表达的有效手段具有特异性强、安全性高、操作简单、靶基因范围广等特点,已被广泛应用于基因治疗肿瘤和病毒相关疾病的研究,反义RNA治疗肿瘤可以通过抑制癌基因的表达、封闭融合癌基因、抑制肿瘤细胞的耐药性、调节细胞因子的表达量等途径;反义RNA治疗病毒相关疾病多集中在艾滋病上,其手段主要是反义封闭TAR。反义RNA作为基因治疗的新途径具有良好的前景,但在设计上和应用上还存在一些急待解决的问题。