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BACKGROUND: Urinary N (1) ,N (12)-diacetylspermine (DiAcSpm) is a novel tumour marker that can be used to detect early cancers. In this study, we examined whether spot urine samples could represent the daily excretion of DiAcSpm after creatinine normalization and which factors should be taken into account in determining reference values for this biomarker. METHODS: We collected the following urine samples: (1) samples from seven healthy volunteers collected on each day of two 2-day sessions to examine the circadian variation of DiAcSpm excretion; (2) samples from 3952 male and 1782 female volunteers to estimate the DiAcSpm concentrations in apparently healthy adults and (3) samples from 16 female volunteers collected every morning over a 3-month period to examine the menstruation-related variation in DiAcSpm excretion. The DiAcSpm concentrations were determined by enzyme-linked immunosorbent assay or a colloidal gold aggregation procedure using DiAcSpm-specific antibodies. RESULTS: (1) The circadian variation of DiAcSpm in the urine was greatly diminished after creatinine normalization. (2) DiAcSpm was higher in females than in males, and the creatinine-normalized medians (95th percentile) of the urinary DiAcSpm concentrations were 149 (305) and 100 (192) nmol/g creatinine for females and males, respectively. (3) The mean concentrations of urinary DiAcSpm were lower after menstruation than before menstruation by approximately 30 nmol/g creatinine. CONCLUSION: Spot urine samples obtained at any time of a day may be used to estimate the daily excretion of DiAcSpm in nmol DiAcSpm per gram creatinine. Sex, age and menstrual condition should be considered when determining the reference values for urinary DiAcSpm. [ABSTRACT FROM AUTHOR]

The article presents a study which examines whether samples of spot urine can represent the excretion of N1, N12-diacetylspermine (DiAcSpm) after creatinine normalization. Urine samples from seven healthy volunteers were collected to examine DiAcSpm excretion's circadian variation. The study found the reduction of the circadian variation of DiAcSpm after creatinine normalization. Lower mean concentrations of DiAcSpm was also found after menstruation than before it.

Purpose: N ,N-Diacetylspermine (DiAcSpm) is a tumor marker featured by increase in the urine of patients with cancers, including early colorectal cancer, but where and how DiAcSpm is made remains unclear. We aimed to clarify whether colorectal cancer tissues produce increased amounts of DiAcSpm, and if they do, to examine whether tissue DiAcSpm level may serve as a criterion of tissue malignancy. Methods: Tissue samples were obtained from 140 patients (13 low-grade intraepithelial neoplasia, 98 high-grade intraepithelial neoplasia and 29 colorectal cancer) treated for colorectal cancer and intraepithelial neoplasia at Tokyo Metropolitan Komagome Hospital between November 2007 and April 2011. The DiAcSpm level in cancer and adjacent normal tissue extracts was compared, and its relationship with clinical stages of the diseases was analyzed. Results: DiAcSpm levels were higher in colorectal cancer tissue ( p < 0.01, n = 12) and its liver metastasis ( p < 0.05, n = 5) than in adjacent normal tissues. The tumor/normal ratio of tissue DiAcSpm content was examined for endoscopically obtained tumor and adjacent normal tissues from patients with intraepithelial neoplasia. The ratio was greater than 1.5 in 38 % (5/13) and 78 % (84/108) of low-grade intraepithelial neoplasia and high-grade intraepithelial neoplasia, respectively. Conclusions: Tissue DiAcSpm levels increase in the tissue of colorectal cancer and also in precancerous lesion, such as high-grade intraepithelial neoplasia. The increase is considered a sign that a tissue is acquiring malignant characteristics. It is likely that the DiAcSpm produced by cancer cells is responsible for the frequent increase in urinary DiAcSpm in early cancer patients. [ABSTRACT FROM AUTHOR]

We report the synthesis of a peptide nucleic acid (PNA) monomer containing N 4 -bis(aminomethyl)benzoylated cytosine ( Bz C 2+ base). The Bz C 2+ monomer was incorporated into PNA oligomers using Fmoc-based solid-phase synthesis. The Bz C 2+ base in PNA had two positive charges and exhibited greater affinity for DNA G base than the natural C base. The Bz C 2+ base stabilized PNA-DNA heteroduplexes through electrostatic attractions, even in high salt conditions. The two positive charges on the Bz C 2+ residue did not compromise the sequence specificity of PNA oligomers. These insights will aid the future design of cationic nucleobases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)