Circulating MicroRNA Let-7d in Attention-Deficit/Hyperactivity Disorder.

Up to date, there has been no molecular signature available in the clinical practice for attention-deficit/hyperactivity disorder (ADHD). To investigate circulating miRNA let-7d significance in ADHD, we investigated serum miRNA let-7d in 35 newly diagnosed ADHD subjects who were randomly selected from 406 patients out of 7450 children, paired with gender- and age-matched control through case-control study. We observed that circulating miRNA let-7d was significantly higher in ADHD subjects than in control (p < 0.05). Higher circulation level of miRNA let-7d was significantly associated with ADHD (odds ratio 16.7; 95% confidence, p < 0.05). Meanwhile, serum galectin-3 level was down-regulated in ADHD subjects and the subjects with low galectin-3 expression accounted for 66% in ADHD. The difference of the serum galectin-3 levels between ADHD and non-ADHD groups reached significance (p < 0.05). In 1-year follow-up, a significantly higher rate of clinical improvement was noted in subjects with low level of circulating miRNA let-7d (p < 0.05) than those with high level of circulating miRNA let-7d. Our data demonstrated that miRNA let-7d was elevated in the serum of ADHD subjects, which might be a novel, useful molecule signature for ADHD.

Regulation of integrin αV subunit expression by sulfatide in hepatocellular carcinoma cells.

Integrin is important in migration and metastasis of tumor cells. Changes of integrin expression and distribution will cause an alteration of cellular adhesion and migration behaviors. In this study, we investigated sulfatide regulation of the integrin αV subunit expression in hepatoma cells and observed that either exogenous or endogenous sulfatide elicited a robust upregulation of integrin αV subunit mRNA and protein expression in hepatoma cells. This regulatory effect occurred with a corresponding phosphorylation (T739) of the transcription factor Sp1. Based on the electrophoretic mobility shift assay, sulfatide enhanced the integrin αV promoter activity and strengthened the Sp1 complex super-shift. The results of chromatin immunoprecipitation analysis also indicated that sulfatide enhanced Sp1 binding to the integrin αV promoter in vivo. Silence of Sp1 diminished the stimulation of integrin αV expression by sulfatide. In the early stage of sulfatide stimulation, phosphorylation of Erk as well as c-Src was noted, and inhibition of Erk activation with either U0126 or PD98059 significantly suppressed Sp1 phosphorylation and integrin αV expression. We demonstrated that sulfatide regulated integrin αV expression and cell adhesion, which was associated with Erk activation.

MiR-223 suppresses cell proliferation by targeting IGF-1R.

To study the roles of microRNA-223 (miR-223) in regulation of cell growth, we established a miR-223 over-expression model in HeLa cells infected with miR-223 by Lentivirus pLL3.7 system. We observed in this model that miR-223 significantly suppressed the proliferation, growth rate, colony formation of HeLa cells in vitro, and in vivo tumorigenicity or tumor formation in nude mice. To investigate the mechanisms involved, we scanned and examined the potential and putative target molecules of miR-223 by informatics, quantitative PCR and Western blot, and found that insulin-like growth factor-1 receptor (IGF-1R) was the functional target of miR-223 inhibition of cell proliferation. Targeting IGF-1R by miR-223 was not only seen in HeLa cells, but also in leukemia and hepatoma cells. The downstream pathway, Akt/mTOR/p70S6K, to which the signal was mediated by IGF-1R, was inhibited as well. The relative luciferase activity of the reporter containing wild-type 3'UTR(3'untranslated region) of IGF-1R was significantly suppressed, but the mutant not. Silence of IGF-1R expression by vector-based short hairpin RNA resulted in the similar inhibition with miR-223. Contrarily, rescued IGF-1R expression in the cells that over-expressed miR-223, reversed the inhibition caused by miR-223 via introducing IGF-1R cDNA that didn't contain the 3'UTR. Meanwhile, we also noted that miR-223 targeted Rasa1, but the downstream molecules mediated by Rasa1 was neither targeted nor regulated. Therefore we believed that IGF-1R was the functional target for miR-223 suppression of cell proliferation and its downstream PI3K/Akt/mTOR/p70S6K pathway suppressed by miR-223 was by targeting IGF-1R.

Fucosylated glycan inhibition of human hepatocellular carcinoma cell migration through binding to chemokine receptors.

SMMC-7721 hepatocellular carcinoma cells (HCC) were incubated with fucosylated glycoproteins that had been isolated from retinoic acid-treated cells by affinity chromatography. HCC migration was significantly inhibited by AAL- and LCA-glycoproteins. Glycopeptides, obtained by digestion of the glycoproteins with trypsin and papain, were found to have a similar inhibitory effect on HCC migration as the corresponding glycoproteins. The inhibitory actions of the glycoproteins were almost abolished after digestion with alpha-L-1,3/4- or alpha-L-1,2-fucosidase. Induction of HCC migration with chemokines including interleukin-8 (IL-8), lymphotactin, monocyte chemoattractant protein-1, and stroma cell-derived factor-1 was examined and IL-8 was found to be the most potent. Interestingly, the isolated glycoproteins significantly inhibited HCC migration and F-actin aggregation induced by IL-8, whereas the glycans themselves did not induce F-actin assembly. From receptor binding analysis AAL-glycan was found to bind IL-8 receptors especially CXCR2 directly and such binding could be blocked by 3'- or 2'-fucosyllactose. After CXCR2 silence by target RNAi, the cells almost lost the response to AAL-glycan inhibition. Our findings suggest that fucosylation plays an important role in the interaction between IL-8 and its receptors inducing HCC migration.