Mitsuo Toda

Transcriptional Repression of Cdc25B by IER5 Inhibits the Proliferation of Leukemic Progenitor Cells through NF-YB and p300 in Acute Myeloid Leukemia

The immediately-early response gene 5 (IER5) has been reported to be induced by γ-ray irradiation and to play a role in the induction of cell death caused by radiation. We previously identified IER5 as one of the 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP)-induced transcriptional responses in AML cells, using microarrays that encompassed the entire human genome. However, the biochemical pathway and mechanisms of IER5 function in regulation of the cell cycle remain unclear. In this study, we investigated the involvement of IER5 in the cell cycle and in cell proliferation of acute myeloid leukemia (AML) cells. We found that the over-expression of IER5 in AML cell lines and in AML-derived ALDHhi (High Aldehyde Dehydrogenase activity)/CD34+ cells inhibited their proliferation compared to control cells, through induction of G2/M cell cycle arrest and a decrease in Cdc25B expression. Moreover, the over-expression of IER5 reduced colony formation of AML-derived ALDHhi/CD34+ cells due to a decrease in Cdc25B expression. In addition, over-expression of Cdc25B restored TMPP inhibitory effects on colony formation in IER5-suppressed AML-derived ALDHhi/CD34+ cells. Furthermore, the IER5 reduced Cdc25B mRNA expression through direct binding to Cdc25B promoter and mediated its transcriptional attenuation through NF-YB and p300 transcriptinal factors. In summary, we found that transcriptional repression mediated by IER5 regulates Cdc25B expression levels via the release of NF-YB and p300 in AML-derived ALDHhi/CD34+ cells, resulting in inhibition of AML progenitor cell proliferation through modulation of cell cycle. Thus, the induction of IER5 expression represents an attractive target for AML therapy.

Cycloaddition reactions of 6-cyanobenz[a]indolizines with activated alkynes. Formation of benzo[2.2.3]- and [2.3.4]cyclazines

Cycloaddition reactions of 6-cyanobenz[a]indolizines with activated alkynes such as dimethyl acetylenedicarboxylate, diacetylacetylene, methyl propiolate, methyl trimethylsilylpropiolate, methyl phenylpropiolate, and 4-phenyl-3-butyn-2-one were investigated.

FISCHER INDOLE SYNTHESIS IN THE ABSENCE OF A SOLVENT

The traditional Fischer synthesis of indoles has been investigated and it has been shown that the reaction proceeds in good yield in the absence of a solvent. Introduction In 1883, while studying the reactivity of arylhydrazines and arylhydrazones, Emil Fischer found that, under acidic conditions, enolizable arylhydrazones undergo rearrangement and loss of ammonia to provide indole products (1-3). Subsequent studies suggested a mechanism for the Fischer indole synthesis that proceeds through an initial acid-catalyzed tautomerization of an arylhydrazone to an ene-hydrazine. The ene-hydrazine then undergoes [3,3]-sigmatropic rearrangement to produce a bis-imine intermediate. Subsequent aromatization of the imlnocyclohexadlene ring followed by intramolecular nucleophilic attack produces an aminal, which after loss of ammonia affords the indole product (4). Over 100 years after the initial discovery, the Fischer indole synthesis remains the most commonly employed method for the preparation of Indoles (5,6) Since a novel entry into the Fischer indole synthesis via a palladium-catalyzed strategy for the preparation of hydrazones has recently been developed particularly by Buchwald (7,8), the scope of Fischer Indole synthesis has expanded. Recently combinatorial syntheses of indole derivatives have been reported (9). On the other hand, many advantages of solvent free reactions have been recognized such as reduced pollution, low costs, and simplicity in process and handling (10). We now report that the classical Fischer indole synthesis can be achieved in the absence of a solvent that is followed by a simple work up of the reaction products. Results and Discussion A mixture of Phenylhydrazine l a , 3-pentanone, and p-toluenesulfonic acid (molar ratio 1:1:3) was heated, with mixing, in a test tube, on a water bath, at around 100 °C for 5 mln. The crude product was collected by filtration, washed with water and dried to give 2-ethyl-3-methylindole In Vol. 9. No. 1, 2003 Fischer indole synthesis in the absence of a solvent 82 % yield. Other examples of the reaction products are summarized In Table 1. ρ -TsOH · H 2 0 (3 mmol) \ R2 JHNH2 (HCl) 1 ( 1 mmol) 2 ( 1 mmol) solvent-free 100 °C (250 °C)

Synthesis of double-armed azaoligocycles based upon high pressure aromatic nucleophilic substitution reactions

Title compounds were prepared through high pressure S N Ar reactions (0.8 GPa, 100 ° C) of homopiperazine with five- and six-membered heteroatomic halides, the yields being good to excellent when the halides are activated by electronic effects

Synthesis and evaluation of novel phosphasugar anticancer agents

Starting materials of phosphasugars, 1-phenyl-2-phospholene 1-oxides, were prepared from dienes and phenylphosphonous dichloride (dichlorophenylphosphine). Several substituted novel phosphasugars (3- or 4-halo-substituted)-1-phenyl-2-phospholene 1-oxides as well as 1-phenyl-2-phospholane 1-oxides were prepared from 2-phospholenes. The synthesized compounds were evaluated for their antitumor activities against the leukemia cell lines (U937 and K562) by in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 2,3,4-Tribromo-3-methyl-1-phenylphospholane 1-oxide showed superior antitumor activity against U937 and K562 cell lines in a comparative evaluation with Glivec. The analysis by flow cytometry implied that 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide induced apoptosis to leukemia cell lines.

Reactions of 5-Cyano-1,4-diphenylpyridazino[4,5-a]indolizines with Dimethyl Acetylenedicarboxylate: Regioselective Formation of 1:2 Michael Type Adducts

Reactions of 5-cyano-1,4-diphenylpyridazino[4,5-a]indolizines with dimethyl acetylenedicarboxylate afforded regioselectively the 1:2 adducts in a Michael fashion rather than in a 1,3-dipolar manner. The structure was established by an X-ray crystallography

Selectivity in Consecutive SNAr-Dequaternization Reactions of Chlorodiazines with Tertiary Amines

Abstract Consecutive SNAr-dealkylation reactions of chlorodiazines such as 2-chloropyrimidine and 3, 6-dichloropyridazine with tertiary amines took place in a highly selective fashion.

Synthesis, in vitro and in vivo studies of Gd-DTPA-XDA-D1-Glc(OH) complex as a new potential MRI contrast agent

A new type of dendritic molecules Gd-DTPA-XDA-D1-Glc(OH), which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with two glucose moieties on the molecular surfaces, were readily synthesized with high yield. The structures were established by IR, (1)H, (13)C NMR, and mass spectral studies. Its bio-distribution patterns were evaluated on rats.

Synthesis of metal ion-specific bindings of new functionalized aza-crown ethers

Abstract The high-pressure SNAr reaction was first applied to the synthesis of new functionalized diaza-crown ethers, which are directly connected to various heteroaromatic substituents as cation binding sites. The yields of the reaction were moderate to excellent (51% to quantitative). In a CH2Cl2 liquid membrane cation-transport experiment, diaza-crown ethers having 2′-thiazoyl-, 2′-benzoxazoyl-, 2′-pyrazinyl-, and 6′-pyridazinyl groups exhibited almost perfect Ag + ion selectivity. Cation extraction and 13C-NMR titration experiments revealed that attachment of heteroaromatics to the diaza-crown ring, if in the proper position, provides excellent Ag+ ion specificity. Since the binding and transport selectivity of these crown ethers were higher than those of the known crowns, the high-pressure technique proved a useful method for synthesis odf a new type of specific crown ethers. Single crystals of the complexes of diaza-crown ethers with silver trifluoromethanesulfonate (AgO3SCF3): AgTf and the correspo...

Research on Phospha Sugar Analogues to Develop Novel Multiple Type Molecular Targeted Antitumor Drugs Against Various Types of Tumor Cells

Abstract The synthesis and antitumor activity evaluation of new branched phospha sugars, especially deoxybromophospha sugar derivatives or bromophospholanes of 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DBMPP: 3) and 2,3,4-tribromo-3-methyl-1- phenylphospholane 1-oxide (TBMPP: 4), against various types of leukemia cell lines as well as the results of the mechanistic studies for characterizing and developing the novel multiple type molecular targeted antitumor agents are reported in this paper. DBMPP and TBMPP were prepared from 1-phenyl-3-methyl-2-phospholene 1-oxide (1). The isomer mixture of phospha sugars prepared were evaluated as novel antitumor agents by MTT in vitro method. DBMPP and TBMPP were characterized by flow cytometry and Western blot analysis and were revealed to be potential antitumor agents against leukemia cell lines of K562 (one type of leukemia cell lines of CML) and U937 (one type of leukemia cell lines of AML) as well as against the various types of leukemia cell lines and also against solid tumor cell lines of stomach, skin, and lung cancers by MTT evaluation and observation by a handstand phase-contrast microscope. The results of the flow cytometry indicated that the mechanism of apoptosis induced by phospha sugar derivatives not only to tumor cells of leukemia cell lines of U937 but also to tumor cells of various kinds of leukemia cell lines selectively to decrease the tumor cell viability of various kinds of leukemia cell lines. The Western blot analyses for phospha sugar DBMPP against U937 leukemia cell lines showed that the phospha sugar affected on the expressions of the factors of cell cycles in the manners of suppressing the expression of the accelerator factors of cell cycles of tumor cells and enhancing the expression of suppressor factors of cell cycles of tumor cells by the medications of phospha sugars. TBMPP enhanced the expression of IER5 and then suppressed the expression of Cdc25B, which is the common factor to accelerate the cell cycles of various kinds of tumor cells. Therefore, suppression of the expression of Cdc25B by TBMPP implies that the branched deoxybromophospha sugar derivatives might be novel and potential multiple type molecular targeted antitumor agents against various kinds of tumor cell lines. GRAPHICAL ABSTRACT