We have isolated three types of cDNAs encoding novel ␤1,3-N-acetylglucosaminyltransferases (designated ␤3Gn-T2, -T3, and -T4) from human gastric mucosa and the neuroblastoma cell line SK-N-MC. These enzymes are predicted to be type 2 transmembrane proteins of 397, 372, and 378 amino acids, respectively. They share motifs conserved among members of the ␤1,3-galactosyltransferase family and a ␤1,3-N-acetylglucosaminyltransferase (designated ␤3Gn-T1), but show no structural similarity to another type of ␤1,3-N-acetylglucosaminyltransferase (iGnT). Each of the enzymes expressed by insect cells as a secreted protein fused to the FLAG peptide showed ␤1,3-N-acetylglucosaminyltransferase activity for type 2 oligosaccharides but not ␤1,3-galactosyltransferase activity. These enzymes exhibited different substrate specificity. Transfection of Namalwa KJM-1 cells with ␤3Gn-T2, -T3, or -T4 cDNA led to an increase in poly-N-acetyllactosamines recognized by an anti-i-antigen antibody or specific lectins. The expression profiles of these ␤3Gn-Ts were different among 35 human tissues. ␤3Gn-T2 was ubiquitously expressed, whereas expression of ␤3Gn-T3 and -T4 was relatively restricted. ␤3Gn-T3 was expressed in colon, jejunum, stomach, esophagus, placenta, and trachea. ␤3Gn-T4 was mainly expressed in brain. These results have revealed that several ␤1,3-Nacetylglucosaminyltransferases form a family with structural similarity to the ␤1,3-galactosyltransferase family. Considering the differences in substrate specificity and distribution, each ␤1,3-N-acetylglucosaminyltransferase may play different roles.A family of human ␤1,3-galactosyltransferases (␤3Gal-Ts) 1 consisting of five members (␤3Gal-T1, -T2, -T3, -T4, and -T5) was recently identified (1-4). The first ␤1,3-galactosyltransferase (␤3Gal-T1), which catalyzes the formation of type 1 oligosaccharides, was isolated by us using an expression cloning approach (1). Expression patterns of ␤3Gal-T1 and type 1 oligosaccharides strongly suggested the existence of ␤3Gal-T1 homologs. For instance, type 1-derived oligosaccharides such as sialyl-Le a were known to be expressed in colon and pancreatic cancer cell lines, whereas expression of ␤3Gal-T1 was detected in brain, but not in cancer cells. Our early approach using Southern hybridization failed to detect the existence of ␤3Gal-T1 homologous genes. However, recent accumulation of nucleotide sequence information on human cDNAs and genes such as expressed sequence tags (ESTs) enabled us to search homologous genes that do not have high similarity as detected by hybridization, but show significant similarity. A homology search based on the nucleotide or amino acid sequence of ␤3Gal-T1 led to the isolation of ␤3Gal-T2, -T3, and -T4, indicating that ␤3Gal-Ts form a family (1-3).␤3Gal-T2 catalyzed a similar reaction, but showed different substrate specificity compared with ␤3Gal-T1. The activity of ␤3Gal-T3 has not been detected, whereas the corresponding mouse enzyme exhibits weak ␤3Gal-T activity for both GlcNAc and GalNAc (5). On the other...

MicroRNAs (miRNAs) are a class of small noncoding RNAs that negatively regulate expression of target mRNA. They are involved in many biological processes, including cell proliferation, apoptosis and differentiation, and considered as new therapeutic targets for cancers. In our study, we performed a gain-of-function screen using 319 miRNAs to identify those affecting cell proliferation and death in human colorectal cancer cells (DLD-1). We discovered a number of miRNAs that increased or decreased cell viability in DLD-1. They included known oncogenic miRNAs such as miR-372 and miR-373, and tumor suppressive miRNAs such as miR-124a, but also some for which this information was novel. Among them, miR-491 markedly decreased cell viability by inducing apoptosis. We demonstrated that Bcl-X L was a direct target of miR-491, and its silencing contributed to miR-491-induced apoptosis. Moreover, treatment of miR-491 suppressed in vivo tumor growth of DLD-1 in nude mice. Our study provides a new regulation of Bcl-X L by miR-491 in colorectal cancer cells, and suggests a therapeutic potential of miRNAs for treating colorectal cancer by targeting Bcl-X L .MicroRNAs (miRNAs) are small noncoding RNAs of around 22 nucleotides that are highly conserved across metazoans 1,2 and over 500 human miRNAs have been described.3 miRNAs induce post-transcriptional gene repression by inhibiting translation and/or stabilization of their target mRNAs, and are thus involved in many biological processes including cell proliferation, differentiation, and apoptosis.

We have previously reported that the Neisseria gonorrhoeae isolates from clinical failure cases treated with cefdinir and aztreonam, ␤-lactams exhibited high MICs. These resistant isolates were clearly separated from the isolates exhibiting a low level of resistance to ␤-lactams as shown by the MIC distribution of cefozopran. Restriction fragment length polymorphism DNA typing revealed that the outbreak of cefozopran-resistant isolates in Kitakyushu, Japan, occurred as a result of clonal spread.As a result of the absence of strains of Neisseria gonorrhoeae resistant to the expanded spectrum of cephems, the National Committee for Clinical Laboratory Standards (NCCLS) (8) has not defined the breakpoint MICs of expanded-spectrum cephems such as cefixime (CFM), cefpodoxime (CPD), cefepime (FEP), etc. A previous study reported the incidence of clinical failures in gonococcal urethritis treated with cefdinir (CDR) or aztreonam (ATM) (1). For the N. gonorrhoeae isolates from such clinical failure cases, high-level MICs of CDR, ATM, and other ␤-lactams were observed. In order to investigate the prevalence of these resistant isolates in Kitakyushu, Japan, we examined 54 N. gonorrhoeae isolates from different cases occurring during 1999 for susceptibility to a variety of antimicrobial agents. Forty of 54 strains were isolated from male patients with gonococcal urethritis, while the remaining isolates were from female patients with gonococcal cervicitis. Identification of N. gonorrhoeae and testing for production of ␤-lactamase were performed by ID-test-HN-20 Rapid (Nissui Pharmaceutical Co., Ltd., Tokyo, Japan) using colonies cultured on Thayer-Martin Agar Base, Modified (Nissui Pharmaceutical Co.). The MICs of various antimicrobials were determined by the twofold serial agar dilution method on BBL GC Agar Base (Becton Dickinson and Co., Cockeysville, Md) with 1% BBL IsoVitalX enrichment (Becton Dickinson Europe, Meylan, France) according to the guidelines of the NCCLS (8). The antimicrobial agents used in this study were purchased from or provided by the corresponding companies.The MIC distribution of cefozopran (CZO) for N. gonorrhoeae isolates was divided into two groups. The MICs for the high-level resistance group (8 to 16 g/ml) were more than 16 times greater than the MICs for the susceptible and low-level resistance groups (Ͻ0.5 g/ml). The MICs of CZO were correlated with those of CDR, CPD, cefpirome (CPI), FEP, ATM, cefuroxime, cefotiam, ceftizoxime (ZOX), CFM, and cefcapene (CPN). The MICs of CZO correlated poorly with those of penicillin (PEN), cefmetazole, flomoxef, and cefodizime (CDZ) despite the fact that all 17 CZO-resistant isolates for these four agents belonged to the high-level MIC group. CFM, CDZ and ceftriaxone (CRO) exhibited lower MICs but the resistant isolates belonged to the group with reduced susceptibility to these three agents. These new resistant strains were clearly divided into two groups by the MIC distribution of CZO, with all of the CZO-resistant isolates exhibiting either resistance or ...

MicroRNAs (miRNAs) are a small class of non-coding RNAs that negatively regulate gene expression, and are considered as new therapeutic targets for treating cancer. In this study, we performed a gain-of-function screen using miRNA mimic library (319 miRNA species) to identify those affecting cell proliferation in human epithelial ovarian cancer cells (A2780). We discovered a number of miRNAs that increased or decreased the cell viability of A2780 cells. Pro-proliferative and anti-proliferative miRNAs include oncogenic miR-372 and miR-373, and tumor suppressive miR-124a, miR-7, miR-192 and miR-193a, respectively. We found that overexpression of miR-124a, miR-192, miR-193a and miR-193b inhibited BrdU incorporation in A2780 cells, indicating that these miRNAs affected the cell cycle. Overexpression of miR-193a and miR-193b induced an activation of caspase 3/7, and resulted in apoptotic cell death in A2780 cells. A genome-wide gene expression analysis with miR-193a-transfected A2780 cells led to identification of ARHGAP19, CCND1, ERBB4, KRAS and MCL1 as potential miR-193a targets. We demonstrated that miR-193a decreased the amount of MCL1 protein by binding 3′UTR of its mRNA. Our study suggests the potential of miRNA screens to discover miRNAs as therapeutic tools to treat ovarian cancer.

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Nucleic acid drugs are being developed as novel therapeutic modalities. They have great potential to treat human diseases such as cancers, viral infections, and genetic disorders due to unique characteristics that make it possible to approach undruggable targets using classical small molecule or protein/antibody-based biologics. In this review, I describe the advantages, classification, and clinical status of nucleic acid therapeutics. To date, more than 10 products have been launched, and many products have been tested in clinics. To promote the use of nucleic acid therapeutics such as antibodies, several hurdles need to be surmounted. The most important issue is the delivery of nucleic acids and several other challenges have been reported. Recent advanced delivery platforms are lipid nanoparticles and ligand conjugation approaches. With the progress of exosome biology, exosomes are expected to contribute to the solution of various problems associated with nucleic acid drugs.