Abstract. MicroRNAs (miRNAs/miRs) are a type of highly conserved, small non-coding RNA that are vital to the post-transcriptional regulation of gene expression via base pairing with target mRNA 3'-untranslated regions (3'-UTRs). Several studies have indicated that the abnormal expression of miRNAs occurs frequently in human osteosarcoma (OS). In the present study, the role of miR-26a in the progression and metastasis of OS was investigated using reverse transcription-quantitative polymerase chain reaction, a luciferase activity assay, cell viability assay, in vitro migration and invasion assays, transfection and western blot analysis. miR-26a was upregulated in OS tissues and cell lines, and the expression of miR-26a was indicated to affect the proliferation, migration and invasion of OS Saos-2 cells. At the molecular level, the results showed that glycogen synthase kinase-3β (GSK-3β) was identified as a target of miR-26a, and the ectopic expression of miR-26a inhibited GSK-3β by directly binding to the 3'-UTR. Therefore, the expression of miR-26a was negatively correlated with GSK-3β in the OS tissues. These data suggest that miR-26a is significant in the proliferation of human OS cells due to the direct regulation of Wnt/β-catenin signaling. IntroductionOsteosarcoma (OS) is the most common primary malignant bone tumor, occurring frequently in adolescents and possessing a high malignant severity (1-4). OS is commonly identified on the distal femur and proximal tibia, possessing high rates of recurrence and metastasis, and a poor prognosis. Previously, surgical resection therapy resulted in a poor prognosis for OS patients (2). At present, the molecular pathogenesis and etiology of OS remain unclear. Therefore, the identification of the effector molecules or signaling pathways responsible for regulating tumor growth and metastasis is critical for improving OS treatment.MicroRNAs (miRNAs/miRs) are a type of highly conserved, small non-coding RNA that are vital to the post-transcriptional regulation of gene expression via base pairing with target mRNA 3'-untranslated regions (3'-UTRs) (5,6). Previous studies have indicated that the abnormal expression of miRNAs is closely associated with cell proliferation, apoptosis, metastasis and invasion in human cancers, including OS (7,8). miRNAs function as either tumor suppressors or oncogenes, depending on the role of the target genes. Previous studies have indicated that the inhibition of miR-26a may induce increased apoptosis in primary cultured chronic lymphocytic leukemia cells through suppression of phosphatase and tensin homolog (9). In addition, miR-26a inhibits hepatitis B virus transcription and replication by targeting the host factor cysteine and histidine-rich domain-containing, zinc-binding protein 1 (10).In the present study, the miRNA expression profiles of human OS samples and cell lines were compared with those of adjacent normal skeletal muscle and normal cell lines. miR-26a was indicated to be upregulated in human OS and cell lines, and the expression o...

molecule of IIc is centmsymmetric, which indicates that the dimerization process is a head-btail fahion. The selectivity of the photodimerization of Ia-Ic has been enhanced by using acidic solvent and the reaction speed would be decreased when electron donating gnxlp was introduced in the Qposition of the phenyl group. That the photodimerization is not affected by the presence of oxygen as well as its high stereo-selectivity demonstrated that the reaction proceeded through an excited singlet state. It was also found that under irradiation of short wavelength U V , these dimers underwent photolysis completely to reproduce its bnns-monomers, and then the new formed species changed into their ck-isomers through m -c k isomehtion.

Synthesis and Biological Activity of Novel Tiliroside Derivants. -Newly synthesized title compounds (III) are evaluated for antidiabetic properties in vitro. Tiliroside derivatives (IIIa)-(IIId) cause significant enhancements in glucose consumption by insulin-resistant HepG2 cells compared with control cells treated with metformin. Morover, compound (IIId) significantly activates 5'-monophosphate-activated protein kinase activity and reduces acetyl-CoA carboxylase activity. -(QIN, N.; LI, C.-B.; JIN, M.-N.; SHI, L.-H.; DUAN*, H.-Q.; NIU, W.-Y.; Eur. J. Med. Chem. 46 (2011) 10, 5189-5195, http://dx.