Lysine specific demethylase 1 (LSD1) plays a key role in the regulation of gene expression by removing the methyl groups from methylated Lys4 of histone H3 (H3K4). Here we report the identification of the first small-molecule LSD1-selective inhibitors. These inhibitors show in vivo H3K4-methylating activity and antiproliferative activity and should be useful as lead structures for anticancer drugs and as tools for studying the biological roles of LSD1.
Reduction-oxidation (redox) regulation has been implicated in the activation of the transcription factor NF-B. However, the significance and mechanism of the redox regulation remain elusive, mainly due to the technical limitations caused by rapid proton transfer in redox reactions and by the presence of many redox molecules within cells. Here we establish versatile methods for measuring redox states of proteins and their individual cysteine residues in vitro and in vivo, involving thiolmodifying reagents and LC-MS analysis. Using these methods, we demonstrate that the redox state of NF-B is spatially regulated by its subcellular localization. While the p65 subunit and most cysteine residues of the p50 subunit are reduced similarly in the cytoplasm and in the nucleus, Cys-62 of p50 is highly oxidized in the cytoplasm and strongly reduced in the nucleus. The reduced form of Cys-62 is essential for the DNA binding activity of NF-B. Several lines of evidence suggest that the redox factor Ref-1 is involved in Cys-62 reduction in the nucleus. We propose that the Ref-1-dependent reduction of p50 in the nucleus is a necessary step for NF-B activation. This study also provides the first example of a drug that inhibits the redox reaction between two specific proteins.The redox states of cysteine residues, which can change reversibly within cells, often greatly influence the various properties of proteins, such as protein stability, chaperone activity, enzymatic activity, and protein structure (1-5). It has also been suggested that several transcription factors bind to their cognate sites in a redox-regulated manner. Well characterized cases include the prokaryotic transcription factors SoxR and OxyR, which function as oxidative stress sensors, their DNA binding activated through oxidation of critical cysteine residues (6 -7). In most cases, however, the roles and mechanisms of redox regulation are not fully defined because it is difficult to monitor the alteration of redox states of proteins mainly due to the rapid proton transfer in redox reactions. A few have directly quantified the redox state of cysteine clustered with iron or amounts of oxidized cysteines using physicochemical or biochemical techniques (3, 8 -9), but these methods cannot describe the whole picture of redox states of a protein and are not widely applicable to other proteins. Therefore, most researchers have chosen an indirect way of using cysteine-substitution mutant proteins (3-5, 7).NF-B 1 is a eukaryotic transcription factor that regulates a wide variety of genes involved in immune function and development (10). NF-B is composed of two subunits, p50 and p65, both of which are members of the Rel family of transcription factors. NF-B normally exists in the cytoplasm, forming an inactive ternary complex with the inhibitor protein IB␣. Following the application of appropriate stimuli, NF-B is released from IB␣ and translocates into the nucleus, where it binds DNA and activates transcription of target genes. Mechanisms of NF-B activation have been exten...
Bioflavonoids, extracted from flower petals, were examined for their growth inhibitory effect on cells in culture. They were found to significantly suppress the growth of the cultured cells. Anthocyanins tended to show greater inhibitory effect than other flavonoids. Commercially synthesized or purified aglycones of flavonoids were also studied for their suppression of tumor cells. The anthocyanins were more effective than other flavonoid aglycones, although the aglycones were easily inactivated under the culture conditions.
GEX1A is a microbial product with antitumor activity. HeLa cells cultured with GEX1A accumulated p27(Kip) and its C-terminally truncated form p27*. GEX1A inhibited the pre-mRNA splicing of p27, producing p27* from the unspliced mRNA containing the first intron. p27* lacked the site required for E3 ligase-mediated proteolysis of p27, leading to its accumulation in GEX1A-treated cells. The accumulated p27* was able to bind to and inhibit the cyclin E-Cdk2 complex that causes E3 ligase-mediated degradation of p27, which probably triggers the accumulation of p27. By using a series of photoaffinity-labeling derivatives of GEX1A, we found that GEX1A targeted SAP155 protein, a subunit of SF3b responsible for pre-mRNA splicing. The linker length between the GEX1A pharmacophore and the photoreactive group was critical for detection of the GEX1A-binding protein. GEX1A serves as a novel splicing inhibitor that specifically impairs the SF3b function by binding to SAP155.
BackgroundPeanut (Arachis hypogaea) is an autogamous allotetraploid legume (2n = 4x = 40) that is widely cultivated as a food and oil crop. More than 6,000 DNA markers have been developed in Arachis spp., but high-density linkage maps useful for genetics, genomics, and breeding have not been constructed due to extremely low genetic diversity. Polymorphic marker loci are useful for the construction of such high-density linkage maps. The present study used in silico analysis to develop simple sequence repeat-based and transposon-based markers.ResultsThe use of in silico analysis increased the efficiency of polymorphic marker development by more than 3-fold. In total, 926 (34.2%) of 2,702 markers showed polymorphisms between parental lines of the mapping population. Linkage analysis of the 926 markers along with 253 polymorphic markers selected from 4,449 published markers generated 21 linkage groups covering 2,166.4 cM with 1,114 loci. Based on the map thus produced, 23 quantitative trait loci (QTLs) for 15 agronomical traits were detected. Another linkage map with 326 loci was also constructed and revealed a relationship between the genotypes of the FAD2 genes and the ratio of oleic/linoleic acid in peanut seed.ConclusionsIn silico analysis of polymorphisms increased the efficiency of polymorphic marker development, and contributed to the construction of high-density linkage maps in cultivated peanut. The resultant maps were applicable to QTL analysis. Marker subsets and linkage maps developed in this study should be useful for genetics, genomics, and breeding in Arachis. The data are available at the Kazusa DNA Marker Database (http://marker.kazusa.or.jp).
Selective inhibitors of Jumonji domain-containing protein (JMJD) histone demethylases are candidate anticancer agents as well as potential tools for elucidating the biological functions of JMJDs. On the basis of the crystal structure of JMJD2A and a homology model of JMJD2C, we designed and prepared a series of hydroxamate analogues bearing a tertiary amine. Enzyme assays using JMJD2C, JMJD2A, and prolyl hydroxylases revealed that hydroxamate analogue 8 is a potent and selective JMJD2 inhibitor, showing 500-fold greater JMJD2C-inhibitory activity and more than 9100-fold greater JMJD2C-selectivity compared with the lead compound N-oxalylglycine 2. Compounds 17 and 18, prodrugs of compound 8, each showed synergistic growth inhibition of cancer cells in combination with an inhibitor of lysine-specific demethylase 1 (LSD1). These findings suggest that combination treatment with JMJD2 inhibitors and LSD1 inhibitors may represent a novel strategy for anticancer chemotherapy.
Immunoglobulin A (IgA) is the main antibody isotype secreted into the intestinal lumen. IgA plays a critical role in the defence against pathogens and in the maintenance of intestinal homeostasis. However, how secreted IgA regulates gut microbiota is not completely understood. In this study, we isolated monoclonal IgA antibodies from the small intestine of healthy mouse. As a candidate for an efficient gut microbiota modulator, we selected a W27 IgA, which binds to multiple bacteria, but not beneficial ones such as Lactobacillus casei. W27 could suppress the cell growth of Escherichia coli but not L. casei in vitro, indicating an ability to improve the intestinal environment. Indeed W27 oral treatment could modulate gut microbiota composition and have a therapeutic effect on both lymphoproliferative disease and colitis models in mice. Thus, W27 IgA oral treatment is a potential remedy for inflammatory bowel disease, acting through restoration of host-microbial symbiosis.
We studied histological features and long-term outcomes in patients with progressive familial intrahepatic cholestasis type 1 (PFIC1) after liver transplantation (LT). Histological findings were correlated with the post-LT course and treatment in 11 recipients with PFIC1. Ages at LT varied from 1 to 18 years (median, 4 years). Macrovesicular steatosis was observed in 8 patients at a median of 60 days post-LT (range, 21-191 days). Severe steatosis progressed to steatohepatitis in 7 patients at a median of 161 days (range, 116-932 days). The patients were followed up for a median of 7.3 years (range, 2.3-16.1 years). Six showed bridging fibrosis, with 2 progressing to cirrhosis. One patient with cirrhosis died because of the rupture of a splenic artery aneurysm 13.6 years post-LT. Post-LT refractory diarrhea was present in all 8 having steatosis. Three without post-LT diarrhea showed no allograft steatosis. Bile adsorptive resin therapy reduced the diarrhea and steatosis. Patients with posttransplant steatosis typically had more severe mutations of the ATPase class I type 8B member 1 (ATP8B1) gene and were more likely to have systemic complications such as pancreatitis. In conclusion, allograft steatosis was present in patients with PFIC1, progressing to steatohepatitis and cirrhosis. Because expression of the familial intrahepatic cholestasis 1 gene occurs in several organs, including the small intestine, pancreas, and liver, and it is involved in enterohepatic bile acid circulation, post-LT steatosis may be due to a malfunction of the ATP8B1 product. Liver Transpl 15:610-618, 2009.
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