MicroRNA miR-199a* regulates the MET proto-oncogene and the downstream extracellular signal-regulated kinase 2 (ERK2).

MicroRNAs (miRNAs) constitute a class of small noncoding RNAs that play important roles in a variety of biological processes including development, apoptosis, proliferation, and differentiation. Here we show that the expression of miR-199a and miR-199a* (miR-199a/a*), which are processed from the same precursor, is confined to fibroblast cells among cultured cell lines. The fibroblast-specific expression pattern correlated well with methylation patterns: gene loci on chromosome 1 and 19 were fully methylated in all examined cell lines but unmethylated in fibroblasts.

Immune activation by siRNA/liposome complexes in mice is sequence- independent: lack of a role for Toll-like receptor 3 signaling.

Improvement in the pharmacokinetic properties of short interfering RNAs (siRNAs) is a prerequisite for the therapeutic application of RNA interference technology. When injected into mice as unmodified siRNAs complexed to DOTAP/Chol-based cationic liposomes, all 12 tested siRNA duplexes caused a strong induction of cytokines including interferon alpha, indicating that the immune activation by siRNA duplexes is independent of sequence context. When modified by various combinations of 2'-OMe, 2'-F, and phosphorothioate substitutions, introduction of as little as three 2'-OMe substitutions into the sense strand was sufficient to suppress immune activation by siRNA duplexes, whereas the same modifications were much less efficient at inhibiting the immune response of single stranded siRNAs.

Chemical modification of siRNAs to improve serum stability without loss of efficacy.

Development of RNA interference as a novel class of therapeutics requires improved pharmacokinetic properties of short interfering RNA (siRNA). To confer enhanced serum stability to Sur10058, a hyperfunctional siRNA which targets survivin mRNA, a systematic modification at the 2'-sugar position and phosphodiester linkage was introduced into Sur10058. End modification of three terminal nucleotides by 2'-OMe and phosphorothioate substitutions resulted in a modest increase in serum stability, with 3' end modification being more effective.

DARFA: a novel technique for studying differential gene expression and bacterial comparative genomics.

We have developed a powerful method, named differential analysis of restriction fragments amplification (DARFA), which enables researchers to perform comprehensive transcriptome analysis as well as bacterial DNA fingerprinting. The key feature of this novel technique lies within the usage of a type IIS enzyme, Hpy188III, which cleaves cDNA or genomic DNA at a TC/NNGA recognition sequence. Cleavage at this particular site results in the production of a pool of restriction fragments which can be divided into 120 subsets based on the 2-nt 5'-overhang sequence.