The latent membrane protein (LMP1) of Epstein-Barr virus (EBV) is expressed in EBV-associated nasopharyngeal carcinoma, which is notoriously metastatic. Although it is established that LMP1 represses E-cadherin expression and enhances the invasive ability of carcinoma cells, the mechanism underlying this repression remains to be elucidated. In this study, we demonstrate that LMP1 induces the expression and activity of the DNA methyltransferases 1, 3a, and 3b, using real-time reverse transcription-PCR and enzyme activity assay. This results in hypermethylation of the E-cadherin promoter and down-regulation of E-cadherin gene expression, as revealed by methylation-specific PCR, real-time reverse transcription-PCR and Western blotting data. The DNA methyltransferase inhibitor, 5-Aza-2dC, restores E-cadherin promoter activity and protein expression in LMP1-expressing cells, which in turn blocks cell migration ability, as demonstrated by the Transwell cell migration assay. Our findings suggest that LMP1 down-regulates E-cadherin gene expression and induces cell migration activity by using cellular DNA methylation machinery.

The miRNA participates in a variety of biologic processes, and dysregulation of miRNA is associated with malignant transformation. In this study, we determined specific profile of miRNA associated with oral cancer by using miRNA array screening method. There were 23 miRNAs found with considerably differential expressions between six oral cancer cell lines and five lines of normal oral keratinocytes, in which, 10 miRNAs showed the highest significant difference after independent examination by reverse transcription quantitative PCR. Eight molecules were upregulated, miR-10b, miR-196a, miR-196b, miR-582-5p, miR15b, miR-301, miR-148b, and miR-128a, and two molecules, miR-503 and miR-31, were downregulated. The most upregulated miR-10b was further examined, and its functions were characterized in two oral cancer cell lines. The miR-10b actively promotes cell migration (2.6-to 3.6-fold) and invasion (1.7-to 1.9-fold) but has minimal effect on cell growth or chemo-/radiosensitivity. Furthermore, miR-10b was considerably elevated in the plasma of xenografted tumor mice (20-fold). This upregulation of miR-10b in plasma was further shown in the patients with oral cancer [P < 0.0001, area under curve (AUC) ¼ 0.932] and precancer lesions (P < 0.0001, AUC ¼ 0.967), suggesting that miR-10b possesses a high potential to discriminate the normal subjects. In conclusion, we have identified at least 10 miRNAs significantly associated with oral cancer, including the most elevated miR-10b. The miR-10b actively participates in cancer formation by promoting cell migration and invasion. Our study using clinical samples suggests that plasma miR-10b has high potential as an early detection marker for oral cancer. Cancer Prev Res; 5(4); 665-74. Ó2012 AACR. Impact of this paper:1. miRNA signature of oral cancer was determined. 2. The oncogenic function of miR-10b in oral cancer was first demonstrated. 3. The potential of miR-10b as a circulating biomarker for the early detection of oral cancer was presented.

Children hospitalized with acute gastroenteritis in Chang Gung Children's Hospital from August 2004 through January 2007 were enrolled in the study. Rotavirus and norovirus were detected by reverse-transcriptase polymerase chain reaction with fecal specimens and were genotyped by sequence analysis. The symptoms and complications, in particular convulsions, of acute gastroenteritis caused by rotavirus and norovirus were reviewed and compared. The occurrence of convulsions associated with norovirus infection was specifically analyzed and discussed. The neurological outcomes for all norovirus-infected patients with or without convulsions were followed up for 1 year. Results. Among the 353 patients with acute viral gastroenteritis without coinfection, rotavirus and norovirus isolates were detected in 101 patients (28.6%) and 64 patients (18.1%), respectively. We compared the symptoms between the 2 groups and found that rotavirus caused a higher frequency and longer duration of vomiting and a higher body temperature than did norovirus. Norovirus infection, on the other hand, caused significantly longer hospital stays (mean duration of stay [interquartile range], 6 [5-8] days vs. 5 [4-7] days; P <.001) and a significantly higher incidence of convulsions than did rotavirus infection (29.7% vs. 5%; P <.001). Three of the 19 patients with convulsions showed an abnormal record on electroencephalogram, but none had any neurological sequelae at the subsequent 1-year follow-up. The majority of norovirus strains (41 of the 56 genotypeable strains) belonged to genogroup GGII/4. Conclusions. Norovirus is a major cause of acute gastroenteritis in children. This study identified norovirus as an emerging agent causing convulsive disorder in children, particularly in young infants. Long-term neurological sequelae are uncommon.