Objective: Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females).
Methods: Lymphocytes were exposed to UV-C (254 nm) at the dose rate of 1.5 J/m2/sec. Novobiocin (NOV) and aphidicolin (APC), DNA repair inhibitors, were utilized to imitate the deficiency of DNA repair capacity at the incision and ligation steps of NER. Lymphocytes from each donor were divided into three grougs: UVC group, UVC plus NOV group, and UVC plus APC group. DNA single strand breaks were detected in UVC irradiated cells incubated for 0, 30, 60, 90, 120, 180, and 240 min after UVC irradiation. DNA repair rate (DRR) served as an indicator of DNA repair capacity.
Results: The results indicated that the maximum DNA damage (i.e. maximum tail length) in the UVC group mainly appeared at 90 min. The ranges of DRRs in the UVC group were 62.84%-98.71%. Average DRR value was 81.84%. The DRR difference between males and females was not significant (P < 0.05). However, the average DRR value in the UVC plus NOV group and the UVC plus APC group was 52.98% and 39.57% respectively, which were significantly lower than that in the UVC group (P < 0.01).
Conclusion: The comet assay is a rapid, simple and sensitive screening test to assess individual DNA repair (NER) capacity. It is suggested that the time to detect DNA single strand breaks in comet assay should include 0 (before UV irradiation), 90 and 240 min after exposure to 1.5 J x m(-2) UVC at least. The DRR, as an indicator, can represent the individual DNA repair capacity in comet assay.
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Bioengineered
December 2025
Department of BioMedical Bigdata (BK21) and Research Institute of Life Sciences, Gyeongsang National University, Jinju, Republic of Korea.
Gene editing is emerging as a powerful tool for introducing novel functionalities in mushrooms. While CRISPR/Cas9-induced double-strand breaks (DSBs) typically rely on non-homologous end joining (NHEJ) for gene disruption, precise insertion of heterologous DNA in mushrooms is less explored. Here, we evaluated the efficacy of inserting donor DNAs (8-1008 bp) with or without homologous arms at Cas9-gRNA RNP-induced DSBs.
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January 2025
Department of Tumor Pathology, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji, Fukui, 910-1193, Japan.
Only a few human ovarian endometrioid carcinoma cell lines are currently available, partly due to the difficulty of establishing cell lines from low-grade cancers. Here, using a cell immortalization strategy consisting of i) inactivation of the p16-pRb pathway by constitutive expression of mutant cyclin-dependent kinase 4 (R24C) (CDK4) and cyclin D1, and ii) acquisition of telomerase reverse transcriptase (TERT) activity, we established a human ovarian endometrioid carcinoma cell line from a 46-year-old Japanese woman. That line, designated JFE-21, has proliferated continuously for over 6 months with a doubling time of ~ 55 h.
View Article and Find Full Text PDFDrug Deliv Transl Res
January 2025
Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2E1, Canada.
In this study, a novel inhibitor of ERCC1/XPF heterodimerization, A4, was used as an inhibitor of repair for DNA damage by platinum-based chemotherapeutics. Nano-formulations of A4 were developed, using self-assembly of the following block copolymers: methoxy-poly(ethylene oxide)-block-poly(α-benzyl carboxylate-ε-caprolactone) (PEO-b-PBCL), methoxy-poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-b-PCL), or methoxy-poly(ethylene oxide)-block-poly (D, L, lactide) (PEO-b-PDLA 50-50). The nano-formulations were characterized for their average diameter, polydispersity, morphology, A4 encapsulation and in vitro release.
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January 2025
Cancer Research Group, School of Life Health and Chemical Sciences, The Open University UK, Milton Keynes, UK.
Background: Aggressive Variant Prostate Cancers (AVPCs) are incurable malignancies. Platinum-based chemotherapies are used for the palliative treatment of AVPC. The Polycomb Repressive Complex 2 (PRC2) promotes prostate cancer progression histone H3 Lysine 27 tri-methylation (H3K27me3).
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January 2025
Helsinki University Hospital and University of Helsinki, Department of Obstetrics and Gynecology, Helsinki, Finland; University of Helsinki, Faculty of Medicine, Helsinki University Hospital and Research Program in Applied Tumor Genomics, Department of Pathology, Helsinki, Finland.
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