A non-nucleotide agonist that binds covalently to cysteine residues of STING.

Stimulator of interferon genes (STING) is an ER-localized transmembrane protein and the receptor for 2',3'-cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), which is a second messenger produced by cGAMP synthase (cGAS), a cytosolic double-stranded DNA sensor. The cGAS-STING pathway plays a critical role in the innate immune response to infection of a variety of DNA pathogens through the induction of the type I interferons. Pharmacological activation of STING is a promising therapeutic strategy for cancer, thus the development of potent and selective STING agonists has been pursued. Here we report that mouse STING can be activated by phenylarsine oxide (PAO), a membrane permeable trivalent arsenic compound that preferentially reacts with thiol group of cysteine residue (Cys). The activation of STING with PAO does not require cGAS or cGAMP. Mass spectrometric analysis of the peptides generated by trypsin and chymotrypsin digestion of STING identifies several PAO adducts, suggesting that PAO covalently binds to STING. Screening of STING variants with single Cys to serine residues (Ser) reveals that Cys88 and Cys291 are critical to the response to PAO. STING activation with PAO, as with cGAMP, requires the ER-to-Golgi traffic and palmitoylation of STING. Our results identify a non-nucleotide STING agonist that does not target the cGAMP-binding pocket, and demonstrate that Cys of STING can be a novel target for the development of STING agonist.Key words: STING agonist, cysteine modification, innate immunity, phenylarsine oxide.

Biomimetic Design of a Robustly Stabilized Folded State Enabling Seed-Initiated Supramolecular Polymerization under Microfluidic Mixing.

We have investigated the folding and assembly behavior of a cystine-based dimeric diamide bearing pyrene units and solubilizing alkyl chains. In low-polarity solvents, it forms a 14-membered ring through double intramolecular hydrogen bonds between two diamide units. The spectroscopic studies revealed that the folded state is thermodynamically unstable and eventually transforms into more energetically stable helical supramolecular polymers that show an enhanced chiral excitonic coupling between the transition dipoles of the pyrene units. Importantly, compared to an alanine-based monomeric diamide, the dimeric diamide exhibits a superior kinetic stability in the metastable folded state, as well as an increased thermodynamic stability in the aggregated state. Accordingly, the initiation of supramolecular polymerization can be regulated using a seeding method even under microfluidic mixing conditions. Furthermore, taking advantage of a self-sorting behavior observed in a mixture of l-cysteine- and d-cysteine-based dimeric diamides, a two-step supramolecular polymerization was achieved by stepwise addition of the corresponding seeds.

Multiorgan contribution to non-shivering and shivering thermogenesis and vascular responses during gradual cold exposure in humans.

PURPOSE: Human brown adipose tissue (BAT) is known to be a significant thermoeffector in non-shivering thermogenesis (NST), albeit with individual variations in the BAT activity. We hypothesized that humans with less BAT would have more contribution from the skeletal muscle (SM) to NST or earlier shivering onset and greater vasoconstriction to compensate for less BAT-mediated thermogenesis. METHODS: Eighteen males participated in this study. Their BAT activity and detectable volume were investigated. A gradual cold exposure was conducted for inducing NST at 18.6 °C and initiating shivering at 11.6 °C. The energy expenditure, electromyograph of the pectoralis major, skin blood flow, and rectal (Tre) and skin temperatures were evaluated. RESULTS: BAT volume significantly correlated with the change in metabolic heat production during mild cold phase relative to baseline (NST; r = 0.562, P < 0.05), but not with shivering initiation phase (NST+ ST). SM mass correlated with baseline metabolic heat production (Mbase; r = 0.839, P < 0.01) but not with NST or NST + ST. A positive correlation was noted between BAT volume and Tre at the end of the 18.6 °C exposure period (r = 0.586, P < 0.05), which positively correlated with shivering onset time (r = 0.553, P < 0.05). The skin blood flow, mean skin temperature, and forearm and finger skin temperature difference at the end of the 18.6 °C exposure period did not correlate with NST or BAT volume. CONCLUSION: BAT volume positively correlated with NST. Notably, lower Tre in individuals with less BAT volume induced earlier shivering onset for offsetting the less NST. Whereas, no correlation between metabolic and vasomotor responses was observed.

Atomistic chemical computation of Olefin polymerization reaction catalyzed by (pyridylamido)hafnium(IV) complex: Application of Red Moon simulation.

We have realized the microscopic simulation of olefin polymerization, that is, the simulation of the catalytic polymerization (CP) reaction system composed of (pyridylamido)hafnium(IV) complex as the catalyst. For this purpose, we adopted Red Moon (RM) method, a novel molecular simulation method to simulate the complex reaction system. First, according to the previous research, with the help of the QM calculation, we proposed a model system and elementary processes and explained the theoretical treatment of the simulation by the RM method (the RM simulation). In addition, we also proposed a macroscopic simulation based on chemical kinetics simulation. Then, we performed two simulations and compared them in terms of the effective time evolution of the three macroscopic physical quantities, the number-average molecular weight Mn , the mass-average molecular weight Mw , and the molar-mass dispersity DM . The comparison showed that the two simulations are in quantitative or partially qualitative agreement with each other. Therefore, it is concluded that the RM simulation could not only simulate the CP reaction process microscopically, but also it is connected essentially to reproduce the time evolution of the macroscopic physical quantities on the basis of its microscopic simulation data. © 2018 Wiley Periodicals, Inc.

Probing the Most Stable Isomer of Zirconium Bis(phenoxy-imine) Cation: A Computational Investigation.

The possibility of coexistence of multiple isomers for zirconium bis(phenoxy-imine) catalyst has been systematically studied by computational approaches. The energetics among the five different isomers of neutral Zr-catalyst have been assessed quantum mechanically. The results suggest that isomer cis-N/trans-O/cis-Me is the most stable among the five isomers in accordance with the general observations of these kinds of phenoxy-imine catalyst. However, for the polymerization reaction, the active species is known to be the cationic form of the Zr-catalyst. The Zr-cation can exist in three different isomers, viz., cis-N/trans-O (A), cis-N/cis-O (B), and trans-N/cis-O (C), and the presence of flexible ligands makes the modeling considerably challenging to determine the most preferable isomers. For the efficient modeling, altogether 80 different structures for each of the three cationic isomers have been generated by using molecular dynamics simulations, and subsequently, the quantum mechanical optimization of these structures has been performed to obtain the most preferable conformation for each isomer. The existing probability derived from the obtained free energy values suggests that isomer C is comparable with isomer A. Even more, isomer A of the cation can be present in two different conformations, where the orientation of side groups is altered at the imine nitrogen atoms. The transition state calculations also confirm that the Zr-cation can exist as a mixture of three structures, "up-down" and "down-down" orientations of the isomers A along with isomer C's "up-up" orientation. However, by varying the substituents at imine nitrogen atoms, one could modulate multimodal to unimodal polymerization behavior of the Zr-catalysts. We believe that this study should provide a starting point for theoretically exploring the mechanistic pathway of the complicated polymerization reactions.

Seeded Polymerization through the Interplay of Folding and Aggregation of an Amino-Acid-based Diamide.

Amino acid based diamides are widely used as a substructure in supramolecular polymers and are also key components of polypeptides that help to understand protein folding. The interplay of folding and aggregation of a diamide was used to achieve seed-initiated supramolecular polymerization. For that purpose, a pyrene-substituted diamide was synthesized in which pyrene is used as a tracer to monitor the supramolecular polymerization. Thermodynamics and time-dependent studies revealed that the folding of the diamide moiety, via the formation of intramolecular hydrogen bonds, effectively prevents a spontaneous nucleation that leads to supramolecular polymerization. Under such out-of-equilibrium conditions, the addition of seeds successfully initiates the supramolecular polymerization. These results demonstrate the utility of such amino acid based diamides in programmable supramolecular polymerizations.

Classical and semiclassical dynamics in statistical environments with a mixed dynamical and statistical representation.

We present a basic theory to study real-time dynamics embedded in a large environment that is treated using a statistical method. In light of great progress in the molecular-level studies on time-resolved spectroscopies, chemical reaction dynamics, and so on, not only in the gas phase but also in condensed phases like liquid solvents and even in crowded environments in living cells, we need to bridge over a gap between statistical mechanics and microscopic real-time dynamics. For instance, an analogy to gas-phase dynamics in which molecules are driven by the gradient of the potential energy hyper-surfaces (PESs) suggests that particles in condensed phases should run on the free energy surface instead. The question is whether this anticipation is correct. To answer it, we here propose a mixed dynamics and statistical representation to treat chemical dynamics embedded in a statistical ensemble. We first define the entropy functional, which is a function of the phase-space position of the dynamical subsystem, being dressed with statistical weights from the statistical counterpart. We then consider the functionals of temperature, free energy, and chemical potential as their extensions in statistical mechanics, through which one can clarify the relationship between real-time microscopic dynamics and statistical quantities. As an illustrative example we show that molecules in the dynamical subsystem should run on the free-energy functional surface, if and only if the spatial gradients of the temperature functional are all zero. Otherwise, additional forces emerge from the gradient of the temperature functional. Numerical demonstrations are presented at the very basic level of this theory of molecular dissociation in atomic cluster solvents.

Atomistic Simulation of Hf-Pyridyl Amido-Catalyzed Chain Transfer Alkene Polymerization Reaction and Its Machine Learning for Extraction of Essential Descriptors: Effect of Microscopic Steric Hindrance on the Monomer Insertion Process.

The microscopic effects of each substituent of the Hf catalyst and the growing polymer on the monomer insertion process were investigated for Hf-pyridyl amido-catalyzed coordinative chain transfer polymerization using the Red Moon method. Since the Hf catalyst has two reaction sites, cis- and trans-sites, we separately applied the appropriate analysis methods to each one, revealing that the naphthalene ring influenced monomer insertion at the cis-one, while the i-Pr group and the hexyl group of the adjacent 1-octene unit did the trans-one. It was interesting to find that the hexyl group of the 1-octene-inserted catalyst (oHfCat) pushes the naphthalene ring toward the cis-site and narrows the space at the cis-site, thus indirectly creating a steric hindrance to cis-insertions. Further, the relative position of the Hf catalyst and the growing polymer was found to be strongly influenced by the patterns of insertion reactions, i.e., cis- or trans-insertions. In particular, it was clarified that, after trans-insertions, the growing polymer on the Hf atom covers the cis-site, making cis-insertion less likely to occur. These studies reveal the microscopic effects of the catalyst substituents and the growing polymer on the catalyst during the polymerization reaction process; these microscopic analyses using the RM method should provide atomistic insights that are not easy to obtain experimentally for advanced catalyst design and polymerization control.

Machine learning­based radiomics models accurately predict Crohn's disease­related anorectal cancer.

The radiological diagnosis of Crohn's disease (CD)-related anorectal cancer is difficult; it is often found in advanced stages and has a poor prognosis because of the difficulty of curative surgery. However, there are no studies on predicting the diagnosis of CD-related cancer. The present study aimed to develop a predictive model to diagnose CD cancerous lesions more accurately in a way that can be interpreted by clinicians. Patients with CD who developed anorectal CD lesions at Hyogo Medical University (Nishinomiya, Japan) between March 2009 and June 2022 were included in the present study. T2-weighted and T1-weighted magnetic resonance (MR) images were utilized for our analysis. Images of anorectal lesions were segmented using open-source 3D Slicer software, and radiomic features were extracted using PyRadiomics. Six machine learning models were investigated and compared: i) Support vector machine; ii) naive Bayes; iii) random forest; iv) light gradient boosting machine; v) extremely randomized trees; vi) and regularized greedy forest (RGF). SHapley Additive exPlanations (SHAP) values were calculated to assess the extent to which each radiomic feature contributed to the model's predictions compared to baseline, represented as the average of the model's predictions for all test data. The T2-weighted images of 28 patients with anorectal cancer and 40 non-cancer patients were analyzed and the contrast-enhanced T1-weighted images of 22 cancer and 40 non-cancer patients. The model with the highest area under the curve (AUC) was the RGF-based model constructed using T2-weighted image features, achieving an AUC of 0.944 (accuracy, 0.862; recall, 0.830). The SHAP-based model explanation suggested a strong association between the diagnosis of CD-related anorectal cancer and features such as complex lesion texture; greater pixel separation within the same coronal cross-section; larger, randomly distributed clumps of pixels with the same signal intensity; and a more spherical lesion shape on T2-weighted images. The MRI radiomics-based RGF model demonstrated outstanding performance in predicting CD-related anorectal cancer. These results may affect the diagnosis and surveillance strategies of CD-related colorectal cancer.

Effects of the use of differential diagnosis checklist and general de-biasing checklist on diagnostic performance in comparison to intuitive diagnosis.

BACKGROUND: How clinicians conduct diagnostic reasoning is a major issue. AIM: To evaluate whether intuitive and analytic processes (differential diagnosis checklist, DDXC; general de-biasing checklist, GDBC) might improve diagnostic performance. METHODS: We enrolled 188 medical students (4th-6th grades) who were divided into two groups and assigned the five cases scenarios. Group 1 (n = 91) were instructed to provide the three most likely diagnoses immediately after reading the scenarios (intuitive diagnosis), then after reading GDBC (diagnosis by GDBC), and finally, after reading DDXC (diagnosis by DDXC). Conversely, group 2 (n = 97) were instructed to provide intuitive diagnoses, by DDXC, and by GDBC. RESULTS: Among the group 1, there was significant difference of total scores (p = 0.01 by ANOVA) between intuitive (8.25) and DDXC (8.77). Among the group 2, we noted significant difference of total scores (p = 0.001 by ANOVA) between intuitive (7.21) and DDXC (7.96). Among the difficult cases, the proportions of correct diagnosis increased after reading DDXC, although among the simple cases, the proportions of correct diagnosis decreased after reading DDXC. CONCLUSION: The use of DDXC, not GDBC, may improve the diagnostic performance in difficult cases, while intuitive process may still be better for simpler cases.

(Pyridylamido)Hf(IV)-Catalyzed 1-Octene Polymerization Reaction Interwoven with the Structural Dynamics of the Ion-Pair-Active Species: Bridging from Microscopic Simulation to Chemical Kinetics with the Red Moon Method.

We performed the atomistic simulation of 1-octene polymerization reaction catalyzed by the ionic pair (IP) consisting of the cationic active species of (pyridylamido)Hf(IV) catalyst, HfCatPn+, and different counteranions (CAs), B(C6F5)4- and MeB(C6F5)3-, at different monomer concentrations. Using a hybrid Monte Carlo/molecular dynamics method, that is, the Red Moon (RM) method, the reaction progress measured by the "RM cycle" was transformed into effective real time using the time transformation theory. Then, the degree of polymerization was found to be consistent with that in the chemical kinetics, a macroscopic theory, and experimental ones. Remarkably, the current simulation has revealed the different dynamical features in the polymerization behavior originating from the CA. Namely, the HfCatPn+-B(C6F5)4- IP mainly forms an outer-sphere IP (OSIP) throughout the polymerization. The HfCatPn+-MeB(C6F5)3- IP, on the other hand, forms an inner-sphere IP (ISIP) in the initial stage of polymerization, and the ratio of ISIP steeply drops after the first monomer insertion because the IP interaction is reduced by the steric hindrance between the inserted monomers and the CA. In conclusion, we have shown that the microscopic IP dynamics interwoven with the polymerization reaction can be computationally observed in the real-time domain by using the RM method. Therefore, our current work demonstrates the promising potential of the RM method in studying catalytic olefin polymerization and complex chemical reaction systems.

Atomistic Chemical Elucidation of the Higher-Rate Reaction Mechanism in Hf-Pyridyl Amido-Catalyzed Copolymerization of Ethene and 1-Octene: Application of Red Moon Simulation with Polymer Propagation Diagrams.

The Hf-pyridyl amido complex ((pyridylamido)Hf(IV)) is a cationic catalyst activated by ion-pairing with auxiliary catalyst B(C6F5)4 to show high activity for α-olefin polymerization. Previously, it was experimentally observed that the consumption rate of 1-octene in the 1-octene/ethene copolymerization is 3-fold compared to the 1-octene homopolymerization in coordinative chain transfer polymerization using the catalyst HfCat+-B(C6F5)4- ion pair (IP) and the chain transfer agent (CTA) ZnEt2. In the present study, we have performed atomistic chemical simulations of the IP-catalyzed homopolymerization of 1-octene and copolymerization of 1-octene and ethene on the basis of the Red Moon (RM) methodology. Using the analysis by polymer propagation diagrams (PPDs), in the 1-octene homopolymerization and the 1-octene/ethene copolymerization with the 1-octene-inserted catalyst (oHfCat), it is theoretically shown that the propagation reactions intermittently pause due to the steric hindrance of two hexyl groups of the oHfCat and the 1-octene inserted adjacent to the Hf atom. On the other hand, in the polymerizations with the ethene-inserted catalyst (eHfCat), it is reasonably recognized that the propagation reactions occur smoothly at a constant rate, and the polymerization continuously proceeds due to the relatively smaller steric hindrance. In conclusion, it was shown, for the first time, that the RM method can be used to reveal the microscopic effects of monomers and substituents in the polymerization reaction processes. Therefore, our current work using PPDs demonstrates the promising potential of the RM methodology in studying catalytic olefin polymerizations and complex chemical reaction systems in general.

Multiple cases of cutaneous Mycobacterium massiliense infection in a "hot spa" in Japan.

Seven body polishers working in the same "hot spa" presented with multiple red nodules and papules on their hands and forearms. A causative agent was successfully isolated from two of the subjects and from a swab sample collected from the underside of a bed cover in the body-polishing facility. The two cutaneous isolates and the environmental isolate were rapidly growing mycobacteria that formed nonphotochromogenic smooth or smooth/rough colonies on Ogawa egg slants. They were identified as Mycobacterium massiliense by multigenotypic analysis using the 16S rRNA, hsp65, and rpoB genes and the 16S-23S rRNA internal transcribed spacer (ITS) region. However, the use of the 16S rRNA gene sequence and/or DNA-DNA hybridization (DDH Mycobacteria Kit) alone would not distinguish M. massiliense from mycobacteria in the M. chelonae-M. abscessus group. The three isolates were significantly more susceptible to clarithromycin, doxycycline, and minocycline than the M. abscessus and M. bolletii reference strains. One cutaneous isolate and the environmental isolate were in a related cluster by randomly amplified polymorphic DNA PCR (RAPD-PCR). Of the several mycobacterial species found in the day spa, only M. massiliense was isolated from biopsy specimens of the skin lesions, suggesting that this bacterium is a human skin pathogen. This is the first known report of cutaneous M. massiliense infections that could not be attributed to a prior invasive procedure. This is also the first report of M. massiliense infection in Japan.

Atomistic Simulation of the Polymerization Reaction by a (Pyridylamido)hafnium(IV) Catalyst: Counteranion Influence on the Reaction Rate and the Living Character of the Catalytic System.

Atomistic simulation of the 1-octene polymerization reaction by a (pyridylamido)Hf(IV) catalyst was conducted on the basis of Red Moon (RM) methodology, focusing on the effect of the counteranions (CAs), MeB(C6F5)3-, and B(C6F5)4-, on the catalyst activity and chain termination reaction. We show that RM simulation reasonably reproduces the faster reaction rate with B(C6F5)4- than with MeB(C6F5)3-. Notably, the initiation of the polymerization reaction with MeB(C6F5)3- is comparatively slow due to the difficulty of the first insertion. Then, we investigated the free energy map of the ion pair (IP) structures consisting of each CA and the cationic (pyridylamido)Hf(IV) catalyst with the growing polymer chain (HfCatPn+), which determines the polymerization reaction rates, and found that HfCatPn+-MeB(C6F5)3- can keep forming "inner-sphere" IPs even after the polymer chain becomes sufficiently bulky, while HfCatPn+-B(C6F5)4- forms mostly "outer-sphere" IPs. Finally, we further tried to elucidate the origin of the broader molecular weight distribution (MWD) of the polymer experimentally produced with B(C6F5)4- than that with MeB(C6F5)3-. Then, through the trajectory analysis of the RM simulations, it was revealed that the chain termination reaction would be more sensitive to the IP structures than the monomer insertion reaction because the former involves a more constrained structure than the latter, which is likely to be a possible origin of the MWDs dependent on the CAs.

Cancer type­SLCO1B3 promotes epithelial­mesenchymal transition resulting in the tumour progression of non­small cell lung cancer.

Non­small cell lung cancer (NSCLC) is one of the most common histologically defined subtypes of lung cancer. To identify a promising molecular target for NSCLC therapy, we performed gene expression analysis at the exon level using postoperative specimens of NSCLC patients. Exon array and real­time PCR analyses revealed that an alternative splicing variant of solute carrier organic anion transporter family member 1B3 (SLCO1B3) called cancer type­SLCO1B3 (Ct­SLCO1B3) was significantly upregulated in the NSCLC samples. SLCO1B3 expressed in the liver [liver type (Lt)­SLCO1B3] was found to be localised in the cell membrane, whereas Ct­SLCO1B3 was detected in the cytoplasm of NSCLC cells. RNAi­mediated knockdown of Ct­SLCO1B3 inhibited in vitro anchorage­independent cell growth, cell migration, and in vivo tumour growth of A549 cells. Overexpression of Ct­SLCO1B3 but not Lt­SLCO1B3 upregulated anchorage­independent cell growth and cell migration of NCI­H23 cells. Mechanistically, Ct­SLCO1B3 was found to regulate the expression of epithelial­mesenchymal transition (EMT)­related genes. The upregulation of E­cadherin was discovered to be especially pivotal to phenotypes of Ct­SLCO1B3­suppressed A549 cells. These findings suggest that Ct­SLCO1B3 functions as a tumour­promoting factor via regulating EMT­related factors in NSCLC.

Prognostic significance of the local expression of interleukin-12 in patients with advanced gastric cancer.

BACKGROUND: Interleukin (IL)-12 is a heterodimeric cytokine that exhibits potent antitumor and antimetastatic activities. Very few studies have so far investigated the local expression of L-12 in tumor specimens of gastric cancer. The purpose of this study was to investigate the immunohistochemical expression of IL-12 in patients with gastric cancer. PATIENTS AND METHODS: IL-12 was immunohistochemically stained using monoclonal antihuman IL-12 antibody (1-1A4) in surgical specimens of 117 gastric cancer patients. The IL-12-positive cell density was calculated. The relationships among the IL-12-positive cell density, clinicopathological factors and 5-year survival rate were evaluated. RESULTS: Among the patients (n=117), the 5-year survival rate after surgery was not statistically different between the patients with high and low IL-12 positive cell-density. However, in the patients with advanced gastric cancer (n=85), those with a high IL-12-positive cell density showed a significantly better prognosis in comparison with those with a low IL-12-positive cell density (p=0.0104). A multivariate analysis indicated that the IL-12-positive cell density and TNM stage are significant prognostic factors. CONCLUSION: IL-12-positive cell density may be a significant independent prognostic factor in surgical specimens of advanced gastric cancer.

Significance of lymphangiogenesis as assessed by immunohistochemistry for podoplanin in patients with esophageal carcinoma.

BACKGROUND: Although lymph node involvement is an important prognostic factor for survival in patients with esophageal carcinoma, little is known about lymphangiogenesis in esophageal carcinoma. Podoplanin, a mutin-type transmembrane glycoprotein, specifically recognizes the lymphatic endothelium and is used as a lymphatic-specific marker. Anti-human podoplanin antibody was therefore used to quantify and evaluate the lymphangiogenesis in esophageal carcinoma. PATIENTS AND METHODS: Lymphatic endothelial cells were detected by immunohistochemistry using mouse monoclonal anti-human podoplanin antibody. The relationship between lymphatic microvessel density (LMVD) and lymphatic vessel invasion (LVI), clinicopathological factors and the prognosis in 29 patients with esophageal carcinoma was investigated. RESULTS: LMVD was significantly higher in esophageal carcinoma patients who had any of the following characteristics: T3-T4 (p=0.0370), tumors more advanced than stage III (TNM staging) (p=0.0351), lymphatic invasion (p=0.0095) and LVI (+) (p=0.0016). LVI significantly correlated with lymph node metastasis (p=0.0003), TNM staging (p=0.0182) and LMVD (p=0.0388). The survival rate of patients with a low LMVD tended to be higher than that of patients with a high LMVD (5-year survival rate, 62.5% vs. 29.4%, p=0.0832). CONCLUSION: The evaluation of lymphangiogenesis using podoplanin immunohistochemistry may be useful in predicting lymph node metastasis and the prognosis in patients with esophageal carcinoma.

4- [3,5-bis(trimethylsilyl)benzamido] benzoic acid (TAC-101) induced fas expression and activated caspase-3 and -8 in a DLD-1 colon cancer cell line.

BACKGROUND: 4-[3,5-Bis (trimethylsilyl) benzamido] benzoic acid (TAC-101) is a novel retinobenzoic acid derivative which has a specific binding affinity to the retinoic acid receptors (RAR)alpha and RARbeta. Using time-dependent FACScan analysis, it was observed that TAC-101 induced apoptosis in a DLD-1 human colon cancer cell line. In this study, the induction of apoptosis-related proteins and the activities of caspases in a DLD-1 cell line under medication with TAC-101 were investigated. MATERIALS AND METHODS: DLD-1 cells were cultured with different concentrations of TAC-101 for 12, 24 and 48 h. The expressions of Fas, TNF-R1, DR3, bcl-2, Bax and Bid were measured using a Western blot analysis. The activities of caspase-3, -8 and -9 were measured using a colorimetric protease assay kit. RESULTS: The Western blot analysis showed that TAC-IO1 had almost no effect on the level of Bcl-2, Bax or Bid protein. Although TAC-101 did not change the expression of TNF-R1 and DR3, TAC-101 increased the expression of Fas in both a time- and a dose-dependent manner. A 3-fold increase in caspase-3 activity and a 1.5-fold increase in caspase-8 activity were observed in cells treated with TAC-101 in comparison to the control cells (p<0.01). CONCLUSION: Our data indicate that the death receptor root of the apoptotic signal transduction in DLD-1 cells mainly participates in the apoptotic induction of TAC-101. Because the compounds inducing apoptotic activity are frequent targets of cancer therapy, TAC-101 may be a good candidate for use in the treatment of colon cancer.

Correlation between the urinary dihydrouracil-uracil ratio and the 5-FU plasma concentration in patients treated with oral 5-FU analogs.

BACKGROUND: The determination of dihydropyrimidine dehydrogenase (DPD) deficiency is important in avoiding severe 5-fluorouracil (FU) toxicity. The dihydrouracil (UH2)-uracil (Ura) ratio (UH2/Ura) in plasma might be an important indicator of the risk of 5-FU catabolic deficiency. In order to clarify this possibility, the pyrimidine metabolites and the UH2/Ura were measured in urine and the plasma level of 5-FU was evaluated in patients with gastric and colorectal cancer. PATIENTS AND METHODS: Patients with primary gastric (n=14) and colorectal (n=8) cancer who had undergone surgery were recruited in this study. These patients were divided into the S-1 treatment group, which drug is a novel oral formulation of tegafur, oxonic acid and 5-chloro-2, 4-dihydroxypyridine (CDHP) (n=14) and a group receiving other drugs which include UFT (Uracil/Tegafur) or oral doxifluridine (n=8). The urinary levels of UH2 and Ura were measured by high-performance liquid chromatography (HPLC) using column swiching. The plasma level of 5-FU was assessed by gas chromatography-mass spectrometry (GC-MS). RESULTS: The UH2/Ura or UH2/Ura (treated/no treated) in the S-1 group significantly decreased in comparison to that in the other-drug group and the plasma 5-FU concentration in the S-1 group significantly increased compared to that in the group treated with other drugs. The plasma 5-FU concentration levels significantly indicated a positive correlation with urinary Ura. Moreover, UH2/Ura treated with 5-FU analogs or UH2/Ura (treated/no treated) significantly showed a negative correlation with the plasma 5-FU concentration levels. CONCLUSION: Our findings indicate that either urinary Ura, the UH2/Ura or UH2/Ura (treated/no treated) can predict the plasma 5-FU concentration levels or DPD deficiencies.

Formation of Reactant Complex Structure for Initiation Reaction of Lactone Ring-Opening Polymerization by Cooperation of Multiple Cyclodextrin.

Ring-opening polymerization of lactones initiated by cyclodextrins has been reported as a promising polymer synthetic method. To investigate the unknown molecular level mechanism of the initiation reaction, we executed molecular dynamics simulations of model systems composed of single or multiple ß-cyclodextrin (ß-CD) molecules in δ-valerolactone (VL) solvent and explored the reactant complex structures satisfying three conditions (VL inclusion in the ß-CD cavity, hydrogen bonding, and nucleophilic attack) at the same time. As a result, we confirmed the formation of the reactant complex structure. Comparison between the single and multiple ß-CD models revealed that the formation is more frequent and the distance for the nucleophilic attack is shorter in the multiple model. Therefore, we anticipate that the reaction proceeds more efficiently by the cooperation of multiple ß-CDs. This finding will contribute to understanding the reaction mechanism from the atomistic point of view.