Thiamine dilauryl sulphate (TDS) exerts a bacteriostatic effect against Gram-positive bacteria and is used as a food additive. The heartwood extract of the Indian kino tree (Pterocarpus marsupium), a medicinal tree native to India, shows weak antimicrobial effects against bacteria and superficial dermatophyte-infective fungi. Herein, we report that the combination of TDS and P.
View Article and Find Full Text PDFThis study explores the synthesis of unique furanocembranoid-type marine diterpenoid, providencin. Providencin features a highly oxidized structure with two furan rings, two oxirane rings, and a bicyclo[12.2.
View Article and Find Full Text PDFBackground/aim: Nab-paclitaxel is used to treat patients with pancreatic cancer. However, it frequently induces peripheral neuropathy. Notably, pharmacokinetic factors may be associated with neuropathic symptoms as the onset depends on the cumulative dose.
View Article and Find Full Text PDFOpantimycin A, a rare antimycin-class antibiotic without the macrolide core, was isolated from sp. RK88-1355 in 2017. In this study, we explored the total synthesis and stereochemical assignment of opantimycin A.
View Article and Find Full Text PDFAs drug-metabolizing enzyme activities are affected by a variety of factors, such as drug-drug interactions, a method to evaluate drug-metabolizing enzyme activities in real time is needed. In this study, we developed a novel SPECT imaging probe for evaluation of hepatic CYP2D activity. Iodine-123- and 125-labeled 4-iodobenzylmequitazine (I-BMQ) was synthesized with high labeling and purity.
View Article and Find Full Text PDFXenobiotic metabolic reactions in the hepatocyte endoplasmic reticulum (ER) including UDP-glucuronosyltransferase and carboxylesterase play central roles in the detoxification of medical agents with small- and medium-sized molecules. Although the catalytic sites of these enzymes exist inside of ER, the molecular mechanism for membrane permeation in the ER remains enigmatic. Here, we investigated that organic anion transporter 2 (OAT2) regulates the detoxification reactions of xenobiotic agents including anti-cancer capecitabine and antiviral zidovudine, via the permeation process across the ER membrane in the liver.
View Article and Find Full Text PDFAs aberrant accumulation of RNA-DNA hybrids (R-loops) causes DNA damage and genome instability, cells express regulators of R-loop structures. Here we report that RNA-dependent RNA polymerase (RdRP) activity of human telomerase reverse transcriptase (hTERT) regulates R-loop formation. We found that the phosphorylated form of hTERT (p-hTERT) exhibits RdRP activity in nuclear speckles both in telomerase-positive cells and telomerase-negative cells with alternative lengthening of telomeres (ALT) activity.
View Article and Find Full Text PDFPurpose: Treatment with regorafenib, which inhibits vascular endothelial growth factor (VEGF) receptor, frequently results in hand-foot skin reaction (HFSR), requiring treatment discontinuation or dose reduction. In our prospective study of regorafenib on patients with metastatic colorectal cancer, 17% of patients developed grade 3 HFSR. Herein, we retrospectively examined genetic polymorphisms associated with regorafenib-induced severe HFSR.
View Article and Find Full Text PDFBackground: Saccharomyces cerevisiae plays a pivotal role in various industrial processes, including bioethanol production and alcoholic beverage fermentation. However, during these fermentations, yeasts are subjected to various environmental stresses, such as ethanol stress, which hinder cell growth and ethanol production. Genetic manipulations and the addition of natural ingredients rich in antioxidants to the culture have been shown to overcome this.
View Article and Find Full Text PDFUAP56 and URH49 are closely related RNA helicases that function in selective mRNA processing and export pathways to fine-tune gene expression through distinct complex formations. The complex formation of UAP56 and URH49 is believed to play a crucial role in regulating target mRNAs. However, the mechanisms underlying this complex formation have not been fully elucidated.
View Article and Find Full Text PDFmRNA export is an essential pathway for the regulation of gene expression. In humans, closely related RNA helicases, UAP56 and URH49, shape selective mRNA export pathways through the formation of distinct complexes, known as apo-TREX and apo-AREX complexes, and their subsequent remodeling into similar ATP-bound complexes. Therefore, defining the unidentified components of the apo-AREX complex and elucidating the molecular mechanisms underlying the formation of distinct apo-complexes is key to understanding their functional divergence.
View Article and Find Full Text PDFPrevious studies have suggested that the incidence of vincristine-induced peripheral neuropathy (VIPN) is potentially linked with cytochrome P450 (CYP)3A5, a polymorphic enzyme that metabolizes vincristine in vitro, and with concurrent use of azole antifungals such as ketoconazole. The assumed mechanism for these interactions is through modulation of CYP3A-mediated metabolism, leading to decreased vincristine clearance and increased susceptibility to VIPN. Given the controversy surrounding the contribution of these mechanisms, we directly tested these hypotheses in genetically engineered mouse models with a deficiency of the entire murine locus [Cyp3a(-/-) mice] and in humanized transgenic animals with hepatic expression of functional and nonfunctional human CYP3A5 variants.
View Article and Find Full Text PDFPurpose: Capecitabine is a prodrug that converts to 5-fluorouracil (5-FU) in three steps. A previous study showed that ABCA2 rs2271862 (C > T) and ABCG5 rs6720173 were associated with increased clearance of 5-FU and 5'-deoxy-5-fluorouridine, respectively, in Spanish patients with colorectal cancer (CRC) (Br J Clin Pharmacol 2021) and reported that ABCA2 rs2271862 was associated with decreased risk of capecitabine-induced neutropenia. Other studies have reported that ABCB1 rs1128503, rs2032592, and rs1045642 were associated with capecitabine-induced toxicity in Spanish CRC patients (Oncotarget 2015, Phamacogenomics 2010).
View Article and Find Full Text PDFRegorafenib improves the survival of patients with metastatic colorectal cancer (mCRC); however, it is also characterized by detrimental dermal side effects that may require treatment cessation or modified dosing. In our previous prospective pharmacokinetic, pharmacodynamic, and pharmacogenetic studies, 17.5% (7/40) of the patients with mCRC had grade 3 erythema multiforme (EM) that caused treatment discontinuation.
View Article and Find Full Text PDFDrug resistance commonly occurs when treating immunocompromized patients with fungal infections. Dehydrozingerone-a phenolic compound isolated from the rhizome of Zingiber officinale-inhibits drug efflux in Saccharomyces cerevisiae by overexpression of the ATP-binding cassette (ABC) transporter Pdr5p. We aimed to investigate whether dehydrozingerone enhances the antifungal activity of glabridin-an isoflavan isolated from the roots of Glycyrrhiza glabra L.
View Article and Find Full Text PDFBreast cancer resistance protein (BCRP) is expressed on hepatic bile canalicular membranes; however, its impact on substrate drug disposition is limited. This study proposes an in vivo knockdown approach using adeno-associated virus encoding short hairpin RNA (shRNA) targeting the bcrp gene (AAV-shBcrp) to clarify the substrate, the overall disposition of which is largely governed by hepatic Bcrp. The disposition of the tyrosine kinase inhibitor, regorafenib, was first examined in bcrp gene knockout (Bcrp) and wild-type (WT) mice, as it was sequentially converted to active metabolites M - 2 and M - 5, which are BCRP substrates.
View Article and Find Full Text PDFBackground: Gefitinib is recommended as a first-line treatment option for elderly patients with non-small cell lung cancer (NSCLC). Because no pharmacokinetics of gefitinib have been examined, we prospectively assessed the pharmacokinetics of gefitinib in patients with epidermal growth factor receptor gene-mutated advanced NSCLC who were 75 years or older.
Methods: Gefitinib was orally administered once daily at a dose of 250 mg.
Recent in vitro reconstitution analyses have proven that the physical interaction between the exosome core and MTR4 helicase, which promotes the exosome activity, is maintained by either MPP6 or RRP6. However, knowledge regarding the function of MPP6 with respect to in vivo exosome activity remains scarce. Here, we demonstrate a facilitative function of MPP6 that composes a specific part of MTR4-dependent substrate decay by the human exosome.
View Article and Find Full Text PDFObjective: Recently, personal health records (PHR) have become a communication tool between patients and medical professionals. PHR applications (PHR app) can be installed on smartphones to record patient-reported outcomes (PROs). This study prospectively examined whether patients with breast cancer could record PROs, including subjective and objective symptoms, on PHR app.
View Article and Find Full Text PDFBackground: To evaluate the effect of regorafenib on soluble MHC class I polypeptide-related sequence A (MICA) (sMICA) level in vitro. In addition, we clinically examined whether its plasma levels were associated with regorafenib activity in terms of progression-free survival (PFS) in patients with CRC.
Methods: Human CRC cell line HCT116 and HT29 cells were treated with regorafenib and its pharmacologically active metabolites, M2 or M5 at the same concentrations as those in sera of patients.
Calcium homeostasis endoplasmic reticulum protein (CHERP) is colocalized with the inositol 1,4,5-trisphosphate receptor (IP3R) in the endoplasmic reticulum or perinuclear region, and has been involved in intracellular calcium signaling. Structurally, CHERP carries the nuclear localization signal and arginine/serine-dipeptide repeats, like domain, and interacts with the spliceosome. However, the exact function of CHERP in the nucleus remains unknown.
View Article and Find Full Text PDFTyrosine kinase inhibitors (TKIs) are molecular-targeted anticancer drugs. Their benefits are limited by dermal toxicities, including hand-foot skin reaction (HFSR), which is commonly found in skin areas subjected to friction. The present study aimed to explain the incidence of HFSR in patients treated with TKIs by focusing on keratinocyte toxicity and inhibition of vascular endothelial growth factor receptor (VEGFR), which plays an essential role in angiogenesis.
View Article and Find Full Text PDFSingle nucleotide polymorphisms in genes encoding microRNAs (miRNA-SNPs) may affect the maturation steps of miRNAs or target mRNA recognition, leading to changes in the expression of target mRNAs to cause gain- or loss-of-function changes. Several miRNA-SNPs are known to be associated with the risk of diseases such as cancer. The purpose of this study was to comprehensively determine the miRNA-SNPs in Japanese individuals to evaluate the differences in allele frequencies between ethnicities by comparing data from the global population in the 1000 Genomes Project and differences between healthy subjects and cancer patients.
View Article and Find Full Text PDFUsing TSG101 pre-mRNA, we previously discovered cancer-specific re-splicing of mature mRNA that generates aberrant transcripts/proteins. The fact that mRNA is aberrantly re-spliced in various cancer cells implies there must be an important mechanism to prevent deleterious re-splicing on the spliced mRNA in normal cells. We thus postulated that mRNA re-splicing is controlled by specific repressors, and we searched for repressor candidates by siRNA-based screening for mRNA re-splicing activity.
View Article and Find Full Text PDFChem Pharm Bull (Tokyo)
August 2021
By employing a silica-coated magnetite as a catalyst, a silica-catalyzed carboxylative cyclization of propargylic amines with carbon dioxide (CO) proceeded to afford the corresponding 2-oxazolidinones. Moreover, after the reaction, the silica-coated magnetic catalyst was readily recovered by use of an external magnet and could be reused up to six times without deactivation.
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