Phase 2 study of eribulin in patients with previously treated advanced or metastatic soft tissue sarcoma.

Objective: Eribulin, a microtubule dynamics inhibitor, is approved for the treatment of patients with breast cancer and soft tissue sarcoma. We investigated the efficacy and safety of eribulin in Japanese patients with soft tissue sarcoma. Methods: This open-label, multicenter, nonrandomized, Phase 2 study enrolled Japanese patients with measurable, advanced/metastatic soft tissue sarcoma of high/intermediate grade and ≥1 prior chemotherapy for advanced disease. Patients received eribulin mesilate 1.4 mg/m2 intravenously over 2­5 minutes on Days 1 and 8 of a 21-day cycle. The primary endpoint was progression-free rate at 12 weeks. Secondary endpoints included overall survival, progression-free survival and safety. Efficacy analyses were stratified by histology (liposarcoma or leiomyosarcoma, and other subtypes). Results: Overall, 52 patients were enrolled and 51 patients were treated. Patients with liposarcoma/leiomyosarcoma (n = 35) had similar characteristics to those with other subtypes (n = 16), except for a higher proportion of women (63% vs 38%, respectively) and patients with Eastern Cooperative Oncology Group performance status 0 (57% vs 44%). Progression-free rate at 12 weeks was 60% in liposarcoma/leiomyosarcoma patients, 31% in other subtypes and 51% overall. Median progression-free survival was 5.5 months in liposarcoma/leiomyosarcoma patients, 2.0 months in other subtypes and 4.1 months overall. Median overall survival was 17.0 months in liposarcoma/leiomyosarcoma patients, 7.6 months in other subtypes and 13.2 months overall. The most common Grade 3­4 adverse events were neutropenia (86%), leukopenia (75%), lymphopenia (33%), anemia (14%) and febrile neutropenia (8%). Conclusion: Eribulin showed clinical activity with a manageable safety profile in previously treated Japanese patients with advanced/metastatic soft tissue sarcoma.

Isolation and Characterization of Radical Anions Derived from a Boryl-Substituted Diphosphene.

Radical anions of a diphosphene with two boryl substituents were isolated and characterized by single-crystal X-ray diffraction, electron spin resonance (ESR), and UV/Vis absorption spectroscopy as well as DFT calculations. Structural analysis of the radical anions revealed an elongation of the P=P bond and a contraction of the B-P bonds relative to the neutral diphosphene. The UV/Vis spectra of these radical anions showed a strong absorption in the visible region, which was assigned to SOMO-related transitions on the basis of DFT calculations. The ESR spectra revealed that the hyperfine coupling constant with the phosphorus nuclei is the smallest that has been reported thus far. The results of the DFT calculations furthermore suggest that this should be attributed to a soaking of electron spin to the vacant p orbitals of the boryl substituents.

A Boryl-Substituted Diphosphene: Synthesis, Structure, and Reaction with n-Butyllithium To Form a Stabilized Adduct by pπ-pπ Interaction.

A boryl-substituted diphosphene was synthesized through the nucleophilic borylation of PCl3 with a borylzinc reagent, followed by a reduction with Mg. A combined analysis of the resulting diboryldiphosphene by single-crystal X-ray diffraction, DFT calculations, and UV/Vis spectroscopy revealed a σ-electron-donating effect for the boryl substituent that was slightly weaker than that of the 2,4,6-tri-tert-butylphenyl (Mes*) ligand. The reaction of this diboryldiphosphene with (n) BuLi afforded a boryl-substituted phosphinophosphide that was, in comparison with the thermally unstable Mes*-substituted diaryldiphosphene, stabilized by a π-electron-accepting effect of the boryl substituent.

Simplification of the genetic code: restricted diversity of genetically encoded amino acids.

At earlier stages in the evolution of the universal genetic code, fewer than 20 amino acids were considered to be used. Although this notion is supported by a wide range of data, the actual existence and function of the genetic codes with a limited set of canonical amino acids have not been addressed experimentally, in contrast to the successful development of the expanded codes. Here, we constructed artificial genetic codes involving a reduced alphabet. In one of the codes, a tRNAAla variant with the Trp anticodon reassigns alanine to an unassigned UGG codon in the Escherichia coli S30 cell-free translation system lacking tryptophan. We confirmed that the efficiency and accuracy of protein synthesis by this Trp-lacking code were comparable to those by the universal genetic code, by an amino acid composition analysis, green fluorescent protein fluorescence measurements and the crystal structure determination. We also showed that another code, in which UGU/UGC codons are assigned to Ser, synthesizes an active enzyme. This method will provide not only new insights into primordial genetic codes, but also an essential protein engineering tool for the assessment of the early stages of protein evolution and for the improvement of pharmaceuticals.

Constraint-based perturbation analysis with cluster Newton method: a case study of personalized parameter estimations with irinotecan whole-body physiologically based pharmacokinetic model.

BACKGROUND: Drug development considering individual varieties among patients becomes crucial to improve clinical development success rates and save healthcare costs. As a useful tool to predict individual phenomena and correlations among drug characteristics and individual varieties, recently, whole-body physiologically based pharmacokinetic (WB- PBPK) models are getting more attention. WB-PBPK models generally have a lot of drug-related parameters that need to be estimated, and the estimations are difficult because the observed data are limited. Furthermore, parameter estimation in WB-PBPK models may cause overfitting when applying to individual clinical data such as urine/feces drug excretion for each patient in which Cluster Newton Method (CNM) is applicable for parameter estimation. In order to solve this issue, we came up with the idea of constraint-based perturbation analysis of the CNM. The effectiveness of our approach is demonstrated in the case of irinotecan WB-PBPK model using common organ-specific tissue-plasma partition coefficients (Kp) among the patients as constraints in WB-PBPK parameter estimation. RESULTS: We find strong correlations between age, renal clearance and liver functions in irinotecan WB-PBPK model with personalized physiological parameters by observing the distributions of optimized values of strong convergence drug-related parameters using constraint-based perturbation analysis on CNM. The constraint-based perturbation analysis consists of the following three steps: (1) Estimation of all drug-related parameters for each patient; the parameters include organ-specific Kp. (2) Fixing suitable values of Kp for each organ among all patients identically. (3) Re-estimation of all drug-related parameters other than Kp by using the fixed values of Kp as constraints of CNM. CONCLUSIONS: Constraint-based perturbation analysis could yield new findings when using CNM with appropriate constraints. This method is a new technique to find suitable values and important insights that are masked by CNM without constraints.

Multiple amino acid-excluded genetic codes for protein engineering using multiple sets of tRNA variants.

A "simplified genetic code", with only 19 amino acids assigned to the sense codons, was recently developed. In this study, we describe novel simplified codes in which multiple amino acids are simultaneously excluded from the universal code. In the simplest code, tryptophan, cysteine, tyrosine, and asparagine codons are assigned to serine by using four kinds of tRNA (Ser) variants. The results revealed that various sets of amino acids can easily be excluded from the universal code, using our strategy for genetic code simplification. A simplified genetic code is useful as an engineering tool for the improvement of industrial enzymes and pharmaceuticals, and also provides new insights into the assessment of protein evolution. Simplified codes in which multiple amino acids are simultaneously excluded from the code can be more effective tools than codes excluding only one amino acid.

Preparation of organic light-emitting diode using coal tar pitch, a low-cost material, for printable devices.

We have identified coal tar pitch, a very cheap organic material made from coal during the iron-making process, as a source from which could be obtained emissive molecules for organic light-emitting diodes. Coal tar pitch was separated by simple dissolution in organic solvent, and subsequent separation by preparative thin-layer chromatography was used to obtain emissive organic molecules. The retardation factor of preparative thin-layer chromatography played a major role in deciding the emission characteristics of the solution as photoluminescence spectra and emission-excitation matrix spectra could be controlled by modifying the solution preparation method. In addition, the device characteristics could be improved by modifying the solution preparation method. Two rounds of preparative thin-layer chromatography separation could improve the luminance of organic light-emitting diodes with coal tar pitch, indicating that less polar components are favorable for enhancing the luminance and device performance. By appropriate choice of the solvent, the photoluminescence peak wavelength of separated coal tar pitch could be shifted from 429 nm (cyclohexane) to 550 nm (chloroform), and consequently, the optical properties of the coal tar pitch solution could be easily tuned. Hence, the use of such multicomponent materials is advantageous for fine-tuning the net properties at a low cost. Furthermore, an indium tin oxide/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/coal tar pitch/LiF/Al system, in which the emissive layer was formed by spin-coating a tetrahydrofuran solution of coal tar pitch on the substrate, showed a luminance of 176 cd/m(2). In addition, the emission spectrum of coal tar pitch was narrowed after the preparative thin-layer chromatography process by removing the excess emissive molecules.

Caspase-8 mediates mitochondrial release of pro-apoptotic proteins in a manner independent of its proteolytic activity in apoptosis induced by the protein synthesis inhibitor acetoxycycloheximide in human leukemia Jurkat cells.

The cysteine protease caspase-8 plays an essential role in apoptosis induced by death receptors. The protein synthesis inhibitor acetoxycycloheximide (Ac-CHX) has been previously shown to induce rapid apoptosis mediated by the release of cytochrome c in human leukemia Jurkat cells. In this study, the novel molecular mechanism that links caspase-8 to the mitochondrial release of pro-apoptotic proteins has been identified. Jurkat cells deficient in caspase-8 were more resistant to Ac-CHX than wild-type Jurkat cells and manifested decreased apoptosis induction and caspase activation as well as inefficient release of cytochrome c, Smac/DIABLO, and AIF into the cytosol. In contrast to Fas ligand stimulation, the general caspase inhibitor barely prevented the mitochondrial release of these pro-apoptotic proteins in Ac-CHX-treated cells, suggesting that caspase-8 activity is dispensable for triggering the mitochondrial pathway in Ac-CHX-induced apoptosis. Consistent with this notion, caspase-8-deficient Jurkat cells reconstituted with catalytically inactive caspase-8 became sensitive to Ac-CHX and exhibited apoptosis, caspase activation, the liberation of pro-apoptotic proteins into the cytosol, and Bak conformational change as efficiently as wild-type Jurkat cells. Unlike caspase-3, -6, -7, and -9, a small but significant portion of caspase-8 was found to localize in mitochondria before and after exposure to Ac-CHX. These results clearly demonstrate that caspase-8 is able to mediate the mitochondrial release of pro-apoptotic proteins in a manner independent of its proteolytic activity in Ac-CHX-induced apoptosis.