Safety and efficacy of a novel anti-CD19 chimeric antigen receptor T cell product targeting a membrane-proximal domain of CD19 with fast on- and off-rates against non-Hodgkin lymphoma: a first-in-human study.

BACKGROUND: Commercial anti-CD19 chimeric antigen receptor T-cell therapies (CART19) are efficacious against advanced B-cell non-Hodgkin lymphoma (NHL); however, most patients ultimately relapse. Several mechanisms contribute to this failure, including CD19-negative escape and CAR T dysfunction. All four commercial CART19 products utilize the FMC63 single-chain variable fragment (scFv) specific to a CD19 membrane-distal epitope and characterized by slow association (on) and dissociation (off) rates. We hypothesized that a novel anti-CD19 scFv that engages an alternative CD19 membrane-proximal epitope independent of FMC63 and that is characterized by faster on- and off-rates could mitigate CART19 failure and improve clinical efficacy. METHODS: We developed an autologous CART19 product with 4-1BB co-stimulation using a novel humanized chicken antibody (h1218). This antibody is specific to a membrane-proximal CD19 epitope and harbors faster on/off rates compared to FMC63. We tested h1218-CART19 in vitro and in vivo using FMC63-CART19-resistant models. We conducted a first-in-human multi-center phase I clinical trial to test AT101 (clinical-grade h1218-CART19) in patients with relapsed or refractory (r/r) NHL. RESULTS: Preclinically, h1218- but not FMC63-CART19 were able to effectively eradicate lymphomas expressing CD19 point mutations (L174V and R163L) or co-expressing FMC63-CAR19 as found in patients relapsing after FMC63-CART19. Furthermore, h1218-CART19 exhibited enhanced killing of B-cell malignancies in vitro and in vivo compared with FMC63-CART19. Mechanistically, we found that h1218-CART19 had reduced activation-induced cell death (AICD) and enhanced expansion compared to FMC63-CART19 owing to faster on- and off-rates. Based on these preclinical results, we performed a phase I dose-escalation trial, testing three dose levels (DL) of AT101 (the GMP version of h1218) using a 3 + 3 design. In 12 treated patients (7 DLBCL, 3 FL, 1 MCL, and 1 MZL), AT101 showed a promising safety profile with 8.3% grade 3 CRS (n = 1) and 8.3% grade 4 ICANS (n = 1). In the whole cohort, the overall response rate was 91.7%, with a complete response rate of 75.0%, which improved to 100% in DL-2 and -3. AT101 expansion correlates with CR and B-cell aplasia. CONCLUSIONS: We developed a novel, safe, and potent CART19 product that recognizes a membrane-proximal domain of CD19 with fast on- and off-rates and showed significant efficacy and promising safety in patients with relapsed B-cell NHL. TRIAL REGISTRATION: NCT05338931; Date: 2022-04-01.

Anticancer Effect of Gallic Acid on Acidity-Induced Invasion of MCF7 Breast Cancer Cells.

The acidic tumor environment has emerged as a crucial factor influencing the metastatic potential of cancer. We investigated the effect of an acidic environment on the acquisition of metastatic properties in MCF7 breast cancer cells and explored the inhibitory effects of gallic acid. Prolonged exposure to acidic culture conditions (over 12 weeks at pH 6.4) induced the acquisition of migratory and invasive properties in MCF7 cells, accompanied by increased expression of Matrix Metalloproteinase 2 and 9 (MMP2 and MMP9, respectively), together with alterations in E-cadherin, vimentin, and epithelial-to-mesenchymal transition markers. Gallic acid effectively inhibited the survival of acidity-adapted MCF7 (MCF7-6.4/12w) cells at high concentrations (>30 µM) and reduced metastatic characteristics induced by acidic conditions at low concentration ranges (5-20 µM). Moreover, gallic acid suppressed the PI3K/Akt pathway and the nuclear accumulation of ß-catenin, which were elevated in MCF7-6.4/12w cells. These findings highlight the potential of gallic acid as a promising therapeutic agent for metastatic traits in breast cancer cells under acidic conditions.

Gastrointestinal AA Amyloidosis following Recurrent SARS-CoV-2 Infection: A Case Report.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with the overproduction of serum amyloid A protein, resulting in systemic AA amyloidosis. In this report, we describe a case of gastrointestinal (GI) AA amyloidosis following SARS-CoV-2 infection. A 75-year-old male presented to the emergency department with upper abdominal pain 6 weeks post kidney transplantation. He had a history of SARS-CoV-2 infection 4 weeks prior. On day 7 of hospitalization, while receiving conservative management, the patient developed symptoms of cough and fever, leading to a diagnosis of SARS-CoV-2 reinfection. The patient's abdominal pain persisted, and hematochezia developed on day 30 of hospitalization. Esophagogastroduodenoscopy and colonoscopy revealed multiple ulcers in the stomach and colon, with histologic findings revealing the presence of amyloid A. The patient was managed conservatively and was also given remdesivir for the SARS-CoV-2 infection. His clinical symptoms subsequently improved, and endoscopic findings demonstrated improvement in multiple gastric ulcers. GI amyloidosis may be a subacute complication following SARS-CoV-2 infection in immunocompromised patients.

Molecular Basis of Resveratrol-Induced Resensitization of Acquired Drug-Resistant Cancer Cells.

Multidrug resistance (MDR) to anticancer drugs remains a serious obstacle to the success of cancer chemotherapy. Resveratrol, a polyphenol, present in natural products exerts anticancer activity and acts as a potential MDR inhibitor in various drug-resistant cancer cells. In the process of resensitization of drug-resistant cancer cells, resveratrol has been shown to interfere with ABC transporters and drug-metabolizing enzymes, increase DNA damage, inhibit cell cycle progression, and induce apoptosis and autophagy, as well as prevent the induction of epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs). This review summarizes the mechanisms by which resveratrol counteracts MDR in acquired drug-resistant cancer cell lines and provides a critical basis for understanding the regulation of MDR as well as the development of MDR-inhibiting drugs.

Extracellular Acidity-mediated Expression of cPLA2γ Confers Resistance in Gastric Cancer Cells.

BACKGROUND/AIM: Extracellular acidity, a characteristic of solid tumors, has been proposed to be a critical factor for aggravating tumor malignancy and conferring resistance to therapeutics. Recently, acidity has been implicated in inflammatory responses, which are mediated through active lipid metabolites in various human tissues. In the present study, we investigated whether acidity can affect lipid-mediated signaling, and found that phospholipase A2 (PLA2) activity increased at acidic pH in SNU601 and AGS gastric carcinoma cell lines. MATERIALS AND METHODS: To identify the PLA2 isoform that is responsible for the acidity-induced activity, we assessed mRNA levels of cPLA2 isotypes through real-time qPCR, and protein levels through immunoblot assay in cells cultured in acidic medium. RESULTS: It was found that acidic pH conditions markedly elevated the PLA2γ expression. A gene interference study using specific siRNA of cPLA2γ suggested that expression of cPLA2γ in acidic culture conditions may be associated with protection of cancer cells in acidic environment, as shown by cell viability and clonogenic assays. In addition, expression of cPLA2γ appeared to confer cell resistance to anticancer drugs under acidic pH conditions. CONCLUSION: Acidity-induced cPLA2γ expression may exert protective effects by imparting resistance to the gastric cancer cells under acidic environment.

Multifaceted Effect of Rubus Occidentalis on Hyperglycemia and Hypercholesterolemia in Mice with Diet-Induced Metabolic Diseases.

Metabolic syndrome is characterized by a combination of several metabolic disorders, including obesity, hyperglycemia, and hyperlipidemia. A simultaneous occurrence is one of the most crucial features of metabolic syndrome; therefore, we selected an animal model in which this would be reflected. We fed C57BL/6N mice a high-fat diet for 23 weeks to develop metabolic syndrome and examined the efficacy of Rubus occidentalis (RO) for hyperglycemia and hypercholesterolemia. Oral administration of RO for 16 weeks improved hyperglycemia as indicated by significantly decreased fasting glucose levels and a glucose tolerance test. Improvements were also observed in hypercholesterolemia, in which significant decreases in serum total cholesterol, non-high-density lipoprotein (non-HDL) cholesterol, apolipoprotein A-1, and apolipoprotein B levels were observed. The time comparison of major biomarkers, observed at the initiation and termination of the experimental period, consistently supported the beneficial effects of RO on each metabolic phenotype. In addition, RO treatment attenuated the excessive fat accumulation in hepatic and adipose tissue by decreasing the size and number of lipid droplets. These results suggested that RO simultaneously exerted antihyperglycemic and antihyperlipidemic effects in mice with diet-induced metabolic syndrome.

Increasing use of therapeutic apheresis as a liver-saving modality.

INTRODUCTION: Therapeutic plasma exchange (TPE) is used for temporary support of liver function in patients presenting with early graft dysfunction after liver transplantation (LT) or liver surgery. We analyzed the effect of therapeutic apheresis on patients with liver disease. METHODS: Between January 2011 and August 2016, 93 apheresis procedures were performed for 26 patients at our institution. Anti-ABO isoagglutination immunoglobulin (Ig) M titer was checked using a type A and type B 3% red blood cell (RBC) suspension in saline with two-fold serial dilutions of patient serum. Anti-ABO isoagglutination IgG titer was checked by a type A and B 0.8% RBC suspension using a low-ionic strength/Coombs card. RESULTS: ABO-incompatible (ABOi) LT was the most common (n=10, 38.5%) indication for apheresis; early graft dysfunction after LT (n=8, 30.7%) was the second most common. Median initial IgM and IgG anti-ABO titers for ABOi LT recipients were 1:16 (range, 1:8-1:128) and 1:48 (range, 1:8-1:2048). We performed preoperative TPE in 10 recipients (median number of sessions, 1.5; range, 1-11). Among patients with early graft dysfunction, those who underwent living donor LT had better survival (4/4; 100%) than those who underwent nonliving donor LT (0/3; 0%). Patients who underwent living donor LT first and then additional LT also survived after three TPE sessions. CONCLUSION: Therapeutic apheresis is associated with a good survival rate and is essential for liver support in patients with early graft dysfunction after LT or posthepatectomy liver failure and during preparation for ABOi LT.

Effect of Rubus Occidentalis Extract on Metabolic Parameters in Subjects with Prediabetes: A Proof-of-concept, Randomized, Double-blind, Placebo-controlled Clinical Trial.

Rubus occidentalis (RO) has beneficial effects on glucose and lipid profiles in vitro. The aim of the study was to investigate RO extract effect on metabolic parameters in prediabetic patients, adopting a 12-week, randomized, double-blind, placebo-controlled trial. Forty-four patients (age 59.0 ± 8.2 years, 70.5% females, HbA1c 5.8 ± 0.4%) were divided into placebo (n = 13), low-dose RO extract (LRE; n = 14), or high-dose RO extract (HRE; n = 17) groups. Either 900 or 1800 mg per day of RO extract was administered orally. Area under the curve for glucose obtained 2 h after a 75-g oral glucose tolerance test was significantly decreased in the HRE group, compared with the placebo group (-28.1 ± 42.4 vs. +13.4 ± 52.6 mg/dL, p < 0.05). Homoeostasis model assessment-B was increased (+17.11 ± 10.69, +5.24 ± 4.10, and +0.86 ± 6.01 in HRE, LRE, and placebo, respectively, p < 0.05). Serum levels of monocyte chemoattractant protein-1 and oxidized low-density lipoprotein were significantly decreased by treatment in a dose-dependent manner (monocyte chemoattractant protein-1: -35.0 ± 21.2, +8.4 ± 18.1, and +24.2 ± 14.5; oxidized low-density lipoprotein: -19.7 ± 8.5, -13.1 ± 7.2, and -2.2 ± 11.0 in the HRE, LRE, and placebo, respectively, p < 0.05). The results support the beneficial effects of RO extract on the control of glycemia and vascular inflammation in prediabetic patients. (ClinicalTrials.gov: NCT01964703). Copyright © 2016 John Wiley & Sons, Ltd.

ALK-rearranged adenocarcinoma with extensive mucin production can mimic mucinous adenocarcinoma: clinicopathological analysis and comprehensive histological comparison with KRAS-mutated mucinous adenocarcinoma.

We aimed to investigate clinicopathological features and histology of ALK-rearranged adenocarcinomas with extensive mucin production (AEM) that mimic mucinous adenocarcinoma (MA). Retrospectively, 12 cases of AEM and 25 cases of MA harbouring KRAS mutation were retrieved. The clinicopathological profile and detailed histological features were analysed and compared based on the ALK and KRAS status. AEMs occurred in younger patients (p = 0.044) and were characterised by floating tubulopapillary pattern (p < 0.001), prominent nucleolus (p < 0.001), and apical cytoplasmic snouts (p < 0.001). In contrast, KRAS-mutated MAs lacked ALK-specific histological patterns (p < 0.05). Instead, tumour-infiltrating leukocytes (p = 0.018) and smooth cytoplasmic borders (p < 0.001) with vesicular nuclei (p = 0.004) were prominent in KRAS-mutated MAs. AEMs demonstrated characteristic tubulopapillary pattern and apical snouts, which were distinguishing features from MAs with KRAS mutation. Apical snouts can be a useful histological surrogate for ALK rearrangement in the pulmonary adenocarcinomas showing extensive mucin that mimic MA.

Black Raspberry Extract Increased Circulating Endothelial Progenitor Cells and Improved Arterial Stiffness in Patients with Metabolic Syndrome: A Randomized Controlled Trial.

Administration of black raspberry (Rubus occidentalis) is known to improve vascular endothelial function in patients at a high risk for cardiovascular (CV) disease. We investigated short-term effects of black raspberry on circulating endothelial progenitor cells (EPCs) and arterial stiffness in patients with metabolic syndrome. Patients with metabolic syndrome (n = 51) were prospectively randomized into the black raspberry group (n = 26, 750 mg/day) and placebo group (n = 25) during the 12-week follow-up. Central blood pressure, augmentation index, and EPCs, such as CD34/KDR(+), CD34/CD117(+), and CD34/CD133(+), were measured at baseline and at 12-week follow-up. Radial augmentation indexes were significantly decreased in the black raspberry group compared to the placebo group (-5% ± 10% vs. 3% ± 14%, P < .05). CD34/CD133(+) cells at 12-week follow-up were significantly higher in the black raspberry group compared to the placebo group (19 ± 109/µL vs. -28 ± 57/µL, P < .05). Decreases from the baseline in interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were significantly greater in the black raspberry group compared to the placebo group (-0.5 ± 1.4 pg/mL vs. -0.1 ± 1.1 pg/mL, P < .05 and -5.4 ± 4.5 pg/mL vs. -0.8 ± 4.0 pg/mL, P < .05, respectively). Increases from the baseline in adiponectin levels (2.9 ± 2.1 µg/mL vs. -0.2 ± 2.5 µg/mL, P < .05) were significant in the black raspberry group. The use of black raspberry significantly lowered the augmentation index and increased circulating EPCs, thereby improving CV risks in patients with metabolic syndrome during the 12-week follow-up.

Effects of Rubus occidentalis extract on blood pressure in patients with prehypertension: Randomized, double-blinded, placebo-controlled clinical trial.

OBJECTIVE: Black raspberry (Rubus occidentalis) is known for improving vascular function. However, there has been no study evaluating its effects on 24-h systolic and diastolic blood pressure in prehypertensive patients. The aim of this study was to examine those effects. METHODS: Patients with prehypertension (N = 45) were prospectively randomized into a moderate-dose black raspberry group (n = 15, 1500 mg/d), a high-dose black raspberry group (n = 15, 2500 mg/d), or a placebo group (n = 15) during an 8-wk follow-up period. Raspberries were consumed in the form of a dried powder extract that was fashioned into capsules. The capsules contained 187.5 and 312.5 mg of raspberry powder, which was equivalent to 1500 and 2500 mg raspberries. Ambulatory 24-h blood pressure (BP); central BP; pulse-wave velocity; abdominal visceral fat; serum renin; angiotensin-converting enzyme; and inflammatory cytokines such as interleukin-6, tumor necrosis factor-α, C-reactive protein, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and plasminogen activator inhibitor-1 were measured at baseline and at 8-wk follow-up. RESULTS: High-dose black raspberry significantly reduced 24-h systolic blood pressure (SBP; 3.3 ± 10 mm Hg versus -6.7 ± 11.8 mm Hg; P < 0.05) and nighttime SBP (5.4 ± 10.6 mm Hg versus -4.5 ± 11.3 mm Hg; P < 0.05) compared with controls during the 8-wk follow-up. Black raspberry powder did not produce any significant changes in most of the parameters other than BP. CONCLUSION: The use of black raspberry significantly lowered 24-h BP in prehypertensive patients during the 8-wk follow-up. Black raspberry used as a dietary supplement could be beneficial in reducing SBP in prehypertensive patients.

CO2 Chemistry of Phenolate-Based Ionic Liquids.

We synthesized ionic liquids (ILs) comprising an alkylphosphonium cation paired with phenolate, 4-nitrophenolate, and 4-methoxyphenolate anions that span a wide range of predicted reaction enthalpies with CO2. Each phenolate-based IL was characterized by spectroscopic techniques, and their physical properties (viscosity, conductivity, and CO2 solubility) were determined. We use the computational quantum chemical approach paired with experimental results to reveal the reaction mechanism of CO2 with phenolate ILs. Model chemistry shows that the oxygen atom of phenolate associates strongly with phosphonium cations and is able to deprotonate the cation to form an ylide with an affordable activation barrier. The ATR-FTIR and (31)P NMR spectra indicate that the phosphonium ylide formation and its reaction with CO2 are predominantly responsible for the observed CO2 uptake rather than direct anion-CO2 interaction.

Chemically tunable ionic liquids with aprotic heterocyclic anion (AHA) for CO(2) capture.

Ionic liquids (ILs) with aprotic heterocyclic anions, or AHAs, can bind CO2 with reaction enthalpies that are suitable for gas separations and without suffering large viscosity increases. In the present work, we have synthesized ILs bearing an alkyl-phosphonium cation with indazolide, imidazolide, pyrrolide, pyrazolide and triazolide-based anions that span a wide range of predicted reaction enthalpies with CO2. Each AHA-based IL was characterized by NMR spectroscopy and their physical properties (viscosity, glass transition, and thermal decomposition temperature) determined. In addition, the influence of substituent groups on the reaction enthalpy was investigated by measuring the CO2 solubility in each IL at pressures between 0 and 1 bar at 22 °C using a volumetric method. The isotherm-derived enthalpies range between -37 and -54 kJ mol(-1) of CO2, and these values are in good agreement with computed enthalpies of gas-phase IL-CO2 reaction products from molecular electronic structure calculations. The AHA ILs show no substantial increase in viscosity when fully saturated with CO2 at 1 bar. Phase splitting and compositional analysis of one of the IL/H2O and IL/H2O/CO2 systems conclude that protonation of the 2-cyanopyrrolide anion is improbable, and this result was confirmed by the equimolar CO2 absorption in the presence of water. Taking advantage of the tunable binding energy and absence of viscosity increase after the reaction with CO2, AHA ILs are promising candidates for efficient and environmental-friendly absorbents in postcombustion CO2 capture.

Effects of black raspberry on lipid profiles and vascular endothelial function in patients with metabolic syndrome.

Black raspberry (Rubus occidentalis) has been known for its anti-inflammatory and anti-oxidant effects. However, short-term effects of black raspberry on lipid profiles and vascular endothelial function have not been investigated in patients with metabolic syndrome. Patients with metabolic syndrome (n = 77) were prospectively randomized into a group with black raspberry (n = 39, 750 mg/day) and a placebo group (n = 38) during a 12-week follow-up. Lipid profiles, brachial artery flow-mediated dilatation (baFMD), and inflammatory cytokines such as IL-6, TNF-α, C-reactive protein, adiponectin, sICAM-1, and sVCAM-1 were measured at the baseline and at the 12-week follow-up. Decreases from the baseline in the total cholesterol level (-22.8 ± 30.4 mg/dL vs. -1.9 ± 31.8 mg/dL, p < 0.05, respectively) and total cholesterol/HDL ratio (-0.31 ± 0.64 vs. 0.07 ± 0.58, p < 0.05, respectively) were significantly greater in the group with black raspberry than in the placebo group. Increases in baFMD at the 12-week follow-up were significantly greater in the group with black raspberry than in the placebo group (0.33 ± 0.44 mm vs. 0.10 ± 0.35 mm, p < 0.05, respectively). Decreases from the baseline in IL-6 (-0.4 ± 1.5 pg/mL vs. -0.1 ± 1.0 pg/mL, p < 0.05, respectively) and TNF-α (-2.9 ± 4.7 pg/mL vs. 0.1 ± 3.6 pg/mL, p < 0.05, respectively) were significantly greater in the group with black raspberry. The use of black raspberry significantly decreased serum total cholesterol level and inflammatory cytokines, thereby improving vascular endothelial function in patients with metabolic syndrome during the 12-week follow-up.

New pulse wave measurement method using different hold-down wrist pressures according to individual patient characteristics.

In traditional Chinese and Korean medicine, doctors first observe a patient's pulse by gently and strongly pressing their fingers onto the wrist, and then make a diagnosis based on the observed pulse waves. The most common method to implement this diagnostic technique is to mechanically extract the pulse waves by applying a fixed range of pressures for all patients. However, this method does not consider the patients individual characteristics such as age, sex, and skin thickness. In the present study, we propose a new method of pulse wave extraction that incorporates the personal characteristics of the patients. This method measures the pulse wave signal at varying hold-down pressures, rather than applying a fixed hold-down pressure for all patients. To compare this new technique with existing methods, we extracted pulse waves from 20 subjects, and then determined the actual applied pressure at each step, the coefficient of floating and sinking pulse (CFS), and the distinction of floating/sinking pulse for each group. Consequently, each subject had a different pressure range in our proposed method, whereas all subjects had a similar pressure range in the existing method. Four of 20 subjects exhibited different floating/sinking pulse patterns due to the value of the first pressure step and the range of hold-down pressures. These four subjects were categorized as overweight based on BMI. In addition, the moving distance of the proposed method was longer than the existing method (p = 0.003, paired t-test), and the correlation coefficient between CFS values of two different methods was 0.321, indicating that there was no correlation.

Melanoma antigen gene family A as a molecular marker of gastric and colorectal cancers.

The present study aimed to evaluate the role of melanoma antigen family A (MAGEA) in gastric and colorectal cancer cell lines and clinical tissue samples. we used 10 gastric and 9 colorectal cancer cell lines, 20 early-stage and 21 advanced-stage gastric cancer tissues, 20 colon adenomas and 19 colorectal cancer tissues. Real-time RT-PCR assay was used for the determination of MAGEA mRNA levels. Western blot analysis and immunohistochemistry were used for the determination of MAGEA protein levels in cell lines and tissues, respectively. Gastric and colorectal cancer cell lines showed variable mRNA expression levels of MAGEA. The MAGEA protein was detected in 30% of gastric cancer cell lines and in 22.2% of colorectal cancer cell lines. There was a high correlation between mRNA and protein expression. Regarding the clinical samples, MAGEA expression was noted in 25, 28.6 and 31.6%, respectively in early-stage, advanced-stage gastric cancer tissues and colon adenocarcinoma, but was negative in the adjacent normal tissues of the stomach and colon as well as colon adenoma. These results indicate that MAGEA is involved in the carcinogenesis of gastric and colorectal cancer and, therefore, can be used as a diagnostic marker to predict these cancers.

Development of a radial pulse tonometric (RPT) sensor with a temperature compensation mechanism.

Several RPT sensors have been developed to acquire objective and quantitative pulse waves. These sensors offer improved performance with respect to pressure calibration, size and sensor deployment, but not temperature. Since most pressure sensors are sensitive to temperature, various temperature compensation techniques have been developed, but these techniques are largely inapplicable to RPT sensors due to the size restrictions of the sensor, and incompatibility between the compensation techniques and the RPT sensor. Consequently, in this paper a new RPT sensor comprising six piezoresistive pressure sensors and one thermistor has been developed through finite element analysis and then a suitable temperature compensation technique has been proposed. This technique compensates for temperature variations by using the thermistor and simple compensation equations. As verification of the proposed compensation technique, pulse waves of all types were successfully compensated for temperature changes.

Allylic C-H activations using Cu(II) 2-quinoxalinol salen and tert-butyl hydroperoxide.

Using a Cu(II) 2-quinoxalinol salen complex as the catalyst and tert-butyl hydroperoxide (TBHP) as the oxidant, allylic activations of olefin substrates can be converted to the corresponding enones or 1,4-enediones. Excellent yields can be achieved (up to 99%) within a very short reaction time and with great tolerance for additional functional groups. Possible mechanistic pathways have been characterized using Raman spectroscopy, cyclic voltammetry, and theoretical calculations.

Redox energetics of hypercloso boron hydrides B(n)H(n) (n = 6-13) and B12X12 (X = F, Cl, OH, and CH3).

The reduction potentials (E°(Red) versus SHE) of hypercloso boron hydrides B(n)H(n) (n = 6-13) and B(12)X(12) (X = F, Cl, OH, and CH(3)) in water have been computed using the Conductor-like Polarizable Continuum Model (CPCM) and the Solvation Model Density (SMD) method for solvation modeling. The B3LYP/aug-cc-pvtz and M06-2X/aug-cc-pvtz as well as G4 level of theory were applied to determine the free energies of the first and second electron attachment (ΔG(E.A.)) to boron clusters. The solvation free energies (ΔG(solv)) greatly depend on the choice of the cavity set (UAKS, Pauling, or SMD) while the dependence on the choice of exchange/correlation functional is modest. The SMD cavity set gives the largest ΔΔG(solv) for B(n)H(n)(0/-) and B(n)H(n)(-/2-) while the UAKS cavity set gives the smallest ΔΔG(solv) value. The E°(Red) of B(n)H(n)(-/2-) (n = 6-12) with the G4/M06-2X(Pauling) (energy/solvation(cavity)) combination agrees within 0.2 V of experimental values. The experimental oxidative stability (E(1/2)) of B(n)X(n)(2-) (X = F, Cl, OH, and CH(3)) is usually located between the values predicted using the B3LYP and M06-2X functionals. The disproportionation free energies (ΔG(dpro)) of 2B(n)H(n)(-) → B(n)H(n) + B(n)H(n)(2-) reveal that the stabilities of B(n)H(n)(-) (n = 6-13) to disproportionation decrease in the order B(8)H(8)(-) > B(9)H(9)(-) > B(11)H(11)(-) > B(10)H(10)(-). The spin densities in B(12)X(12)(-) (X = F, Cl, OH, and CH(3)) tend to delocalize on the boron atoms rather than on the exterior functional groups. The partitioning of ΔG(solv)(B(n)H(n)(2-)) over spheres allows a rationalization of the nonlinear correlation between ΔG(E.A.) and E°(Red) for B(6)H(6)(-/2-), B(11)H(11)(-/2-), and B(13)H(13)(-/2-).

Histone H4 deacetylation down-regulates catalase gene expression in doxorubicin-resistant AML subline.

We explored if epigenetic mechanisms could be involved in the down-regulated expression of catalase gene (CAT) in the doxorubicin-resistant acute myelogenous leukemia (AML)-2/DX100 cells. Down-regulated CAT expression in AML-2/DX100 cells was completely recovered after treatment of hydrogen peroxide (H(2)O(2)) and histone deacetylase inhibitor, trichostatin A (TSA) but was increased slightly by the treatment of DNA methylation inhibitor, 5-aza-2'-deoxycytidine (5-AdC). Bisulfite-sequencing PCR revealed that a CpG island of CAT was not methylated in AML-2/DX100 cells. Chromatin immunoprecipitation assay confirmed that acetylation of histone H4 in AML-2/DX100 cells significantly decreased as compared with that in AML-2/WT cells, which was significantly increased by TSA more than 5-AdC. Meanwhile, overexpression of other up-regulated peroxidase genes appears to make compensation for decreased H(2)O(2)-scavenging activity for the down-regulated CAT expression in AML-2/DX100 cells. These results suggest that histone H4 deacetylation is responsible for the down-regulated CAT expression in AML-2/DX100 cells, which are well adapted to oxidative stress.