Benzoxaborole Catalyst Embedded with a Lewis Base: A Highly Active and Selective Catalyst for cis-1,2-diol Modification.

The regioselective modification of polyols allows rapid access to their derivatives, thereby accelerating the polyol-related biology and drug discovery. We previously reported that benzoxaborole is a potent catalyst for the regioselective modification of polyols containing a cis-1,2-diol structure. In this study, we developed a bifunctional benzoxaborole catalyst embedded with a Lewis base. Benzoxaborole and Lewis base groups were designed to cooperatively activate a substrate (cis-1,2-diol) and reactant (electrophile), respectively, hence lowering the reaction barrier for the cis-1,2-diol moiety. The bifunctional catalyst indeed exhibited a significantly higher catalytic activity and selectivity for cis-1,2-diol modifications rather than a benzoxaborole catalyst without a Lewis base group. Mechanistic analyses, using both experimental and theoretical methods, supported the design of our catalyst. The bifunctional catalyst reported herein would be a new tool for the straightforward synthesis of polyol derivatives.

A Small Compound, HYGIC, Promotes Hypocotyl Growth Through Ectopic Ethylene Response.

Plant seedlings adjust the growth of the hypocotyl in response to surrounding environmental changes. Genetic studies have revealed key players and pathways in hypocotyl growth, such as phytohormones and light signaling. However, because of genetic redundancy in the genome, it is expected that not-yet-revealed mechanisms can be elucidated through approaches different from genetic ones. Here, we identified a small compound, HYGIC (HG), that simultaneously induces hypocotyl elongation and thickening, accompanied by increased nuclear size and enlargement of cortex cells. HG-induced hypocotyl growth required the ethylene signaling pathway activated by endogenous ethylene, involving CONSTITUTIVE PHOTOMORPHOGENIC 1, ETHYLENE INSENSITIVE 2 (EIN2) and redundant transcription factors for ethylene responses, ETHYLENE INSENSITIVE 3 (EIN3) and EIN3 LIKE 1. By using EBS:GUS, a transcriptional reporter of ethylene responses based on an EIN3-binding-cis-element, we found that HG treatment ectopically activates ethylene responses at the epidermis and cortex of the hypocotyl. RNA-seq and subsequent gene ontology analysis revealed that a significant number of HG-induced genes are related to responses to hypoxia. Indeed, submergence, a representative environment where the hypoxia response is induced in nature, promoted ethylene-signaling-dependent hypocotyl elongation and thickening accompanied by ethylene responses at the epidermis and cortex, which resembled the HG treatment. Collectively, the identification and analysis of HG revealed that ectopic responsiveness to ethylene promotes hypocotyl growth, and this mechanism is activated under submergence.

An Analysis of 20 Cases of Radiation-Associated Sarcoma, Including 4 Cases Treated by Carbon Ion Radiotherapy.

INTRODUCTION: Radiation-associated sarcoma (RAS) is one of the most life-threatening complications associated with the treatment of malignant neoplasms. Because all RAS patients have a history of radiotherapy, there have been no effective treatment options when RAS is not completely resected. METHODS: We retrospectively reviewed 20 RAS patients, including 4 unresectable cases treated by carbon ion radiotherapy (CIRT). RESULTS: The primary diseases targeted by radiotherapy included malignant lymphoma (n = 4), cervical cancer (n = 3), pharyngeal cancer (n = 3), breast cancer (n = 2), lung cancer (n = 1), rectal cancer (n = 1), maxillary cancer (n = 1), synovial sarcoma (n = 1), and benign neoplasms (n = 4). The histological diagnoses of RAS included osteosarcoma (n = 8), leiomyosarcoma (n = 3), undifferentiated pleomorphic sarcoma (n = 3), rhabdomyosarcoma (n = 1), angiosarcoma (n = 1), malignant peripheral nerve sheath tumor (n = 1), spindle cell sarcoma NOS (n = 1), and sarcoma not further specified (n = 2). The median survival time from the diagnosis of RAS was 26 months. Eleven patients underwent surgery. Five of these patients achieved a continuous disease free (CDF) status or showed no evidence disease. Four patients underwent CIRT. One of these patients with leiomyosarcoma achieved a CDF status, and the other patient with osteosarcoma achieved a partial response. On the other hand, 2 patients experienced grade 3 toxicities that required surgical treatment. CONCLUSION: RAS originates from various types of diseases that are treated by radiotherapy and shows diverse pathological features. Complete resection achieves a good prognosis. CIRT can be an effective and feasible option for unresectable RAS.

Development of 1,8-naphthalimide dyes for rapid imaging of subcellular compartments in plants.

Here, we report the installation of 1,8-naphthalimide dyes in live cell imaging of plants. We developed a series of 1,8-naphthalimide-based probes that illuminate different subcellular compartments by altering their spectral characteristics. Simple infiltration of the probes into leaves rapidly visualized the structure of chloroplasts or the vacuole. We further demonstrated that these probes are applicable to monitor the organelle behaviors in an autophagy pathway.

Development of potent inhibitors for strigolactone receptor DWARF 14.

Strigolactones (SLs) are plant hormones that suppress shoot branching through perception by their receptor protein DWARF 14 (D14). The artificial regulation of SL signaling has been considered a potent agricultural technique because plant architecture is strongly related to crop yield. In this communication, we describe the development of a small-molecule D14 inhibitor that functions at sub-micromolar levels. This potent inhibitor may be a lead compound for a first-in-class plant growth regulator.

Modular design for fluorophore homodimer probes using diethylentriamine as a common spacer.

Cationic fluorophore homodimer probes 1 and 2 bearing 7-aminocoumarin and naphthalimide dyes, respectively, connected via diethylenetriamine (DETA) spacer, have been developed to demonstrate the validity of our modular probe design on the basis of the triamine-based spacer.

The Association between Metabolic Syndrome and High-Stage Primary Urothelial Carcinoma of the Bladder.

Recently, metabolic syndrome (MetS) has become an important public health problem, and its prevalence is increasing. MetS is associated with multifactorial diseases. No reports have suggested a relationship between bladder cancer and high blood pressure, and hyperlipidemia has been reported as a possible risk factor. In the present study, we investigated the relationships between the stage and degree of malignancy of bladder cancer and MetS. Furthermore, we investigated the influence of the components of MetS on the results. We retrospectively analyzed the data of 169 patients who underwent transurethral resection of a bladder tumor in our department between Janurary 2005 and March 2011. MetS was significantly associated with a high histological grade (p < 0.05). MetS and low high-density lipo-protein were found to be significantly associated with the T stage; no other components of MetS were associated with a high stage or grade. Our results demonstrated that a lack of therapy for patients with low high-density lipoprotein levels could be riskier than was previously thought.

The combination of paclitaxel and carboplatin as second-line chemotherapy can be a preferred regimen for patients with urothelial carcinoma after the failure of gemcitabine and cisplatin chemotherapy.

There is no established standard second-line chemotherapy after the failure of the first-line cisplatin-based chemotherapy for patients with advanced or metastatic urothelial carcinoma. With regards to second-line chemotherapy, methotrexate, vinblastine, doxorubicin and cisplatin (MVAC) was used from July 2009 onwards, and paclitaxel and carboplatin (TC) was introduced in April 2014 at the National Kyushu Cancer Center. The present study aimed to assess the prognostic factors for overall survival (OS) in second-line treatment that included best supportive care (BSC), and the tolerability and efficacy of TC chemotherapy. In total, 52 patients who were confirmed to have disease progression with first-line gemcitabine and cisplatin (GC) between June 2009 and November 2016 were enrolled in the current study. In addition, 28 patients selected BSC as second-line treatment, while 24 patients received second-line chemotherapy (MVAC, n=8; TC, n=16). The median OS for BSC, MVAC and TC was 2.8, 5.4, and 12.7 months, respectively. The difference between BSC and MVAC was not statistically significant (P=0.596). However, the difference between BSC and TC was statistically significant after Bonferroni correction (P=0.002). Multivariate analyses revealed that anemia [hazard ratio (HR), 7.047; 95% confidence interval (CI), 1.553-35.636; P=0.011], the presence of visceral metastasis (HR, 4.174; 95% CI, 1.506-13.429; P=0.005) and second-line treatment (TC HR, 0.296; 95% CI, 0.124-0.636; P=0.003) were independent prognostic factors. TC achieved an 18.7% overall response rate and a 56.2% disease control rate. Myelosuppression was the most common grade ≥3 toxicity, but no treatment-associated mortalities occurred during the study period. TC was associated with favorable benefits and safety, and may be considered a preferred regimen after the failure of GC.

Progression-free survival of first-line treatment with molecular-targeted therapy may be a meaningful intermediate endpoint for overall survival in patients with metastatic renal cell carcinoma.

The aim of the present study was to investigate the association between clinical parameters and the overall survival (OS) of Japanese patients with metastatic renal cell carcinoma (mRCC). The medical records of 59 consecutive mRCC patients receiving molecular-targeted therapy were retrospectively assessed. Kaplan-Meier and log-rank analyses were used to evaluate the progression-free survival (PFS) and OS, and a multivariate Cox proportional hazard model was used to analyze the clinical parameters for their prognostic relevance. The median OS for all patients was 23.7 months [95% confidence interval (CI): 17.9-30 months], and the median OS stratified by the Memorial Sloan Kettering Cancer Center risk classification was 28.5, 20.9 and 8.1 months for the favorable-, intermediate- and poor-risk groups, respectively (P=0.137; degree of freedom: 2). Univariate analyses identified prior nephrectomy, number of metastatic sites, anemia, best response to first-line treatment and PFS with first-line treatment as prognostic variables. Multivariate analyses identified number of metastatic sites [2: hazard ratio (HR)=3.351, 95% CI: 1.460-8.201, P=0.004; ≥3: HR=6.397, 95% CI: 1.939-20.209, P=0.003], time from diagnosis to therapy (≥1 year: HR=0.334, 95% CI: 0.137-0.755, P=0.008), PFS with first-line treatment (≥5.1 months: HR=0.353, 95% CI: 0.156-0.766, P=0.008) and number of lines of molecular-targeted agents (≥3: HR=0.248, 95% CI: 0.091-0.664, P=0.006) as independent prognostic factors. The results indicated that the PFS of first-line treatment may be a meaningful intermediate endpoint for OS in patients with mRCC who received treatment with molecular-targeted therapy.

Synthesis of Water-Soluble Cyclophane Hexamers Having a Triphenylene Core and Their Enhanced Guest-Binding Behavior.

A key compound, a precursor of water-soluble cyclophane hexamer, was prepared via Williamson ether synthesis of tetraaza[6.1.6.1]paracyclophane derivatives bearing a bromoacetamide moiety with triphenylene-2,3,6,7,10,11-hexaol as a core. A cationic cyclophane hexamer (1) was obtained by removing the protecting groups from the precursor. Fluorescence titration experiments proved that cationic cyclophane hexamer 1 showed macrocyclic multivalency effects; i.e., 1:1 host/guest binding constants (K) of 1 with anionic guests, 6-anilinonaphthalene-2-sulfonate and 6-p-toluidinonaphthalene-2-sulfonate, were increased about 63- and 62-fold, respectively, relative to those of monomeric cyclophane. Similarly, anionic cyclophane hexamer 2, which was easily prepared from 1, showed macrocyclic multivalency effects in K values with cationic guests such as hydrochlorides of doxorubicin and daunorubicin as an anticancer drug.

Enantioselective synthesis of 3-arylquinazolin-4(3H)-ones via peptide-catalyzed atroposelective bromination.

We report the development of a tertiary amine-containing ß-turn peptide that catalyzes the atroposelective bromination of pharmaceutically relevant 3-arylquinazolin-4(3H)-ones (quinazolinones) with high levels of enantioinduction over a broad substrate scope. The structure of the free catalyst and the peptide-substrate complex were explored using X-ray crystallography and 2D-NOESY experiments. Quinazolinone rotational barriers about the chiral anilide axis were also studied using density functional theory calculations and are discussed in light of the high enantioselectivities observed. Mechanistic studies also suggest that the initial bromination event is stereodetermining, and the major monobromide intermediate is an atropisomerically stable, mono-ortho-substituted isomer. The observation of stereoisomerically stable monobromides stimulated the conversion of the tribromide products to other atropisomerically defined products of interest. For example, (1) a dehalogenation Suzuki-Miyaura cross-coupling sequence delivers ortho-arylated derivatives, and (2) a regioselective Buchwald-Hartwig amination procedure installs para-amine functionality. Stereochemical information was retained during these subsequent transformations.

Biotinylated Cyclophane: Synthesis, Cyclophane-Avidin Conjugates, and Their Enhanced Guest-Binding Affinity.

Cationic and anionic cyclophanes bearing a biotin moiety were synthesized as a water-soluble host (1a and 1b, respectively). Both hosts 1a and 1b were found to strongly bind avidin with binding constants of 1.3 × 10(8) M(-1), as confirmed by surface plasmon resonance measurements. The present conjugate of 1a with avidin (1a-avidin) showed an enhanced guest binding affinity toward fluorescence guests such as TNS and 2,6-ANS. The K values of 1a-avidin conjugate with TNS and 2,6-ANS were ~19-fold larger than those of monocyclic cyclophane 1a with the identical guests. Favorable hydrophobic and electrostatic interactions between 1a-avidin and TNS were suggested by computer-aided molecular modeling calculations. Moreover, addition of excess biotin to the complexes of 1a-avidin with the guests resulted in dissociation of 1a-avidin to avidin and 1a having less guest-binding affinity. Conversely, such enhancements in the guest-binding affinity were not obviously observed for the conjugate of anionic 1b with avidin (1b-avidin) due to electrostatic repulsion between anionic 1b and anionic guests.

Crosslinking reactions of 4-amino-6-oxo-2-vinylpyrimidine with guanine derivatives and structural analysis of the adducts.

DNA interstrand crosslinks (ICLs) are the primary mechanism for the cytotoxic activity of many clinical anticancer drugs, and numerous strategies for forming ICLs have been developed. One such method is using crosslink-forming oligonucleotides (CFOs). In this study, we designed a 4-amino-6-oxo-2-vinylpyrimidine (AOVP) derivative with an acyclic spacer to react selectively with guanine. The AOVP CFO exhibited selective crosslinking reactivity with guanine and thymine in DNA, and with guanine in RNA. These crosslinking reactions with guanine were accelerated in the presence of CoCl2, NiCl2, ZnCl2 and MnCl2. In addition, we demonstrated that the AOVP CFO was reactive toward 8-oxoguanine opposite AOVP in the duplex DNA. The structural analysis of each guanine and 8-oxoguanine adduct in the duplex DNA was investigated by high-resolution NMR. The results suggested that AOVP reacts at the N2 amine in guanine and at the N1 or N2 amines in 8-oxoguanine in the duplex DNA. This study demonstrated the first direct determination of the adduct structure in duplex DNA without enzyme digestion.

Development of the crosslinking reactions to RNA triggered by oxidation.

A novel crosslink-forming nucleobase, 2-amino-6-(1-ethylthiovinyl)purine (ATVP), which is triggered by the oxidation of sulfide to sulfoxide, has been developed. The oxidation of ATVP within the duplex proceeded with H2O2 and FeCl2. We have successfully developed the crosslinking reactions activated by oxidation.

The Crosslink formation of 2'-OMe oligonucleotide containing 2-amino-6-vinylpurine protects mRNA from miRNA-mediated silencing.

Masking the miRNA binding site: Crosslink-forming oligonucleotide (CFO) was used for target gene-specific inhibition of microRNA (miRNA) functions. This method can interfere with specific miRNA-mRNA interactions by recognizing sequences unique to the 3'-UTR that are inherent in each mRNA.

Synthesis of peptide-conjugated light-driven molecular motors and evaluation of their DNA-binding properties.

Synthetic light-driven molecular motors are molecular machines capable of rotation under photo-irradiation. In this paper, we report the synthesis of peptide-conjugated molecular motors and evaluate their DNA-binding properties.

Synthesis of 6-amino-2-vinylpurine derivatives for cross-linking and evaluation of the reactivity.

Oligodeoxynucleotides (ODNs) have been widely used for inhibiting the gene expression in antisense or antigene methods, and the interstrand cross-linking (ICL) forming ODNs have been expected to ensure the inhibition by these methods. Previously, we reported a highly efficient and selective ICL reaction toward cytosine using the 2-amino-6-vinylpurine derivative under acidic conditions. In this Letter, we report the synthesis of ODN containing 6-amino-2-vinylpurine derivatives and evaluation of the cross-linking reactivity.

Production of truncated protein by the crosslink formation of mRNA with 2'-OMe oligoribonucleotide containing 2-amino-6-vinylpurine.

The development of convenient methods for controlling the protein expression is an important challenge in the postgenomic era. We applied the crosslink forming oligonucleotide (CFO) as a terminator of the ribosomal translation. In this study, we demonstrated that the improved reactivity of our CFO under physiological conditions enabled the sequence-specific introduction of a steric block for a ribosome on mRNAs. In vitro and in cell translation experiments revealed that the crosslinked mRNA can produce the truncated proteins in which the translation terminates at the desired position.

Formation of highly selective and efficient interstrand cross-linking to thymine without photo-irradiation.

Interstrand cross-linking (ICL) forming oligodeoxynucleotides (ODNs) have been expected to ensure the inhibition of gene expression. In this communication, we report a highly efficient and selective ICL reaction to thymine using a 4-amino-2-vinyl-6-oxopyrimidine derivative.

Design and synthesis of the novel cross-linking agent.

Previously, we have developed a highly efficient and selective cross-linking reaction to the cytosine base at the target site of DNA using the oligodeoxynucleotide (ODN) containing 2-amino-6-vinylpurine derivative (1). Based on these results, we have designed the novel cross-linking agents, which are pyrimidine derivatives having two hydrogen bond sites and vinyl group as a reactive moiety. In this paper, we wish to report the results to investigate on the synthesis of the pyrimidine derivatives having potential as novel cross-linking agents.