Specific residues at every third position of siRNA shape its efficient RNAi activity

Small interfering RNA (siRNA) induces sequence-specific post-transcriptional gene silencing in mammalian cells. Different efficacy of each siRNA is considered to result from sequence preference by protein components in RNAi. To obtain mechanistic insight into siRNA functionality, here we describe a complete data set of siRNA activities targeting all possible position of a single mRNA in human cells. Seven hundred and two siRNAs covering open reading frame of enhanced green fluorescent protein mRNA ( 720 bases) were examined with minimized error factors. The most important finding is that specific residues at every third position of siRNAs greatly influence its RNAi activity; the optimized base composition at positions 3n + 1 (4,7,10,13,16,19) in siRNAs have positive effects on the activity, which can explain the waving siRNA activity with 3 nucleotides (nt) periodicity in the sequential positions of mRNAs. Since there was an obvious correlation between siRNA activity and its binding affinity to TRBP, a partner protein of human Dicer, the 3-nt periodicity might correlate with the affinity to TRBP. As an algorithm (‘siExplorer’) developed by this observation successfully calculated the activities of siRNAs targeting endogenous human genes, the 3-nt periodicity provides a new aspect unveiling siRNA functionality

Obstructions of Portal Veins and Tumor Numbers Are Associated with Humped Hepatocellular Carcinoma

Tumor protrusion in hepatocellular carcinoma (HCC) is one of the risk signs of tumor rupture. Despite curative tumor treatments, HCC recurrences sometimes occur with rapidly growing humped or ruptured HCC in small sized tumors. The aim of this study was to clarify the characteristics of humped HCC clinically and radiologically associated with tumor progression, liver damage, and treatment. The subjects were 179 consecutive HCC patients who underwent angiographic examination. Dynamic studies, using helical computed tomography and magnetic resonance imaging were assessed, and the HCC area were measured. The tumor-node-metastasis (TNM) stage differed significantly between the humped and non-humped HCC groups. Humped HCC was more frequently observed in the right lobe (29.3% of right-lobe HCCs) than in the left (10.1%;p＝0.003). Analysis of recurrent HCC revealed that patients with multiple treatments of >4 sessions had more humped HCC (33.8%) than those with 1-3 sessions (16.7%;p＝0.042). Multivariate regression analysis revealed that tumor invasion in the portal vein, rather than large tumor size, was significantly associated with tumor protrusion. HCC recurrence with humped HCC occurs often in patients with multiple treatments. Tumor factors of the TNM classification, especially tumor invasion in the portal vein, might be associated with the mechanisms of tumor protrusion

Competences in Project Management: A Case Study in Osaka Institute of Technology

This chapter briefly explains the distributed project management of four joint departments for first-grade joint project-based learning (PBL). That is, conventional studies and purpose, capital, competence and ability of four kinds of distributed project management were presented, and relations among them are shown after describing background (included prehistory of PBL in Osaka Institute of Technology (O.I.T.)). Then, consideration and analysis about communication, interaction, cooperation, merit, week-point, effect and inference were discussed. Some case studies were described about open innovation and competences in stakeholder management. They were distinctive and superior in first-grade PBL of O.I.T. Finally, some future themes were presented

Use of fluid-attenuated inversion recovery (FLAIR) pulse sequences for differential diagnosis of hepatic hemangiomas and hepatic cysts

Fluid-attenuated inversion recovery (FLAIR) imaging of hepatic hemangiomas (10 patients, 16 lesions) and hepatic cysts (8 patients, 10 lesions) was performed. All hemangiomas were hypointense on T1-weighted images and hyperintense on T2-weighted images. With Gd-DTPA (0.1 mmol/kg), all hemangiomas were enhanced but not all cysts. It was necessary to perform contrast enhanced imaging to differentiate hepatic hemangiomas from hepatic cysts. However, on FLAIR imaging, hepatic hemangiomas were strongly hyperintense and 9 of the 10 hepatic cysts were isointense. One of the hepatic cysts was slightly hyperintense. FLAIR images were useful in differential diagnosis of hepatic hemangiomas and hepatic cysts without using Gd-DTPA.</p

Detection of subependymal veins using high-resolution magnetic resonance venography

High-resolution magnetic resonance venography (HR-MRV) of intracranial subependymal veins using a two-dimensional Fourier-transform time-of-flight technique was performed on normal volunteers and clinical cases of cerebral disease. For the pulse sequence, fast-field-echo sequence was used with the following parameters: TR/TE/ flip angle = 34ms/12ms/50deg., 256 x 256 matrix, 1 mm effective slice thickness, 150mm field of view, and one signal acquisition. Sequential vertical coronal sections were taken against the skull base. The anterior septal vein, the medial atrial vein, the anterior caudate vein and thalamostriate vein were detected in all subjects. In all clinical cases, HR-MRV was equal in diagnostic capability to conventional cerebral angiography.</p

Mamld1 Knockdown Reduces Testosterone Production and Cyp17a1 Expression in Mouse Leydig Tumor Cells

MAMLD1 is known to be a causative gene for hypospadias. Although previous studies have indicated that MAMLD1 mutations result in hypospadias primarily because of compromised testosterone production around the critical period for fetal sex development, the underlying mechanism(s) remains to be clarified. Furthermore, although functional studies have indicated a transactivation function of MAMLD1 for the non-canonical Notch target Hes3, its relevance to testosterone production remains unknown. To examine these matters, we performed Mamld1 knockdown experiments.Mamld1 knockdown was performed with two siRNAs, using mouse Leydig tumor cells (MLTCs). Mamld1 knockdown did not influence the concentrations of pregnenolone and progesterone but significantly reduced those of 17-OH pregnenolone, 17-OH progesterone, dehydroepiandrosterone, androstenedione, and testosterone in the culture media. Furthermore, Mamld1 knockdown significantly decreased Cyp17a1 expression, but did not affect expressions of other genes involved in testosterone biosynthesis as well as in insulin-like 3 production. Hes3 expression was not significantly altered. In addition, while 47 genes were significantly up-regulated (fold change >2.0×) and 38 genes were significantly down-regulated (fold change <0.5×), none of them was known to be involved in testosterone production. Cell proliferation analysis revealed no evidence for compromised proliferation of siRNA-transfected MLTCs.The results, in conjunction with the previous data, imply that Mamld1 enhances Cyp17a1 expression primarily in Leydig cells and permit to produce a sufficient amount of testosterone for male sex development, independently of the Hes3-related non-canonical Notch signaling

昭和南海地震震源域-四国沖～紀伊半島沖-の構造変化

BE12-54講演要旨 / ブルーアース2012（2012年3月22日～23日, 東京海洋大学品川キャンパス