There is a need to develop risk biomarkers during the remediation of contaminated land. We employed the earthworm, Aporrectodea longa (Ude), to determine whether genotoxicity measures could be applied to this organism's intestinal tissues. Earthworms were added, for 24h or 7 days, to soil samples spiked with benzo[a]pyrene (B[a]P) and/or lindane. After exposure, intestinal tissues (crop/gizzard or intestine) were removed prior to the measurement in disaggregated cells of DNA single-strand breaks (SSBs) by the alkaline comet assay. Damage was quantified by comet tail length (CTL, microm). B[a]P 24-h exposure induced dose-related increases (P<0.0001) in SSBs. Earthworm intestine was significantly (P<0.0001) more susceptible than crop/gizzard to B[a]P and/or lindane. However, both tissues appeared to acquire resistance following 7-day exposure. B[a]P-DNA adducts, measured by (32)P-postlabelling, showed a two-adduct-spot pattern. This preliminary investigation suggests that earthworm tissues may be incorporated into genotoxicity assays to facilitate hazard identification within terrestrial ecosystems.
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http://dx.doi.org/10.1016/j.envpol.2005.03.012 | DOI Listing |
Biol Methods Protoc
December 2024
School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, P.R. China.
Peroxidase DNAzymes are single-stranded, stable G-quadruplexes structures that exhibit catalytic activity with cofactor hemin. This class of DNAzymes offers several advantages over traditional protein and RNA catalysts, including thermal stability, resistance to hydrolysis, and easy of synthesis in the laboratory. However, their use in medicine, biology, and chemistry is limited due to their low catalytic rates.
View Article and Find Full Text PDFJ Nucl Med
January 2025
Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, Heidelberg, Victoria, Australia;
Novel radiation sensitizers, including inhibitors targeting DNA damage response, have been developed to enhance the efficacy of anticancer treatments that induce DNA damage in cancer cells. Peposertib, a potent, selective, and orally administered inhibitor of DNA-dependent protein kinase, impedes the nonhomologous end-joining mechanism for DNA double-strand break (DSB) repair. We investigated radioimmunotherapy alone or with peposertib in preclinical models of renal cell carcinoma (RCC) or prostate cancer.
View Article and Find Full Text PDFTalanta
January 2025
College of Science, Nanjing Forestry University, Nanjing, 210037, China. Electronic address:
Organic field-effect transistors (OFETs) integrated with commercial transistors are promising sensing platforms characterized by enhanced device uniformity, functional diversity, and electrical output stability. Aptamers with charged backbones and a high affinity for target molecules are anticipated to mitigate the limitations imposed by Debye screening in physiological environments with high ionic strength, thereby facilitating specific biological recognition in complex surroundings. This study presents two reliable OFET aptasensors for vascular endothelial growth factor (VEGF) and offers a systematic comparison of their performance.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Maidashi 3-1-1, Higashi-Ku, Fukuoka 812-8582, Japan.
An enzyme with strong single-stranded DNA (ssDNA) ligation activity would be advantageous for many molecular biology applications. However, currently available enzymes exhibit only limited activity. Here, we identified an enzyme with strong ssDNA ligation activity upon searching the databases for proteins homologous to TS2126 RNA ligase, the known enzyme with the highest yet limited ssDNA ligation activity.
View Article and Find Full Text PDFJ Biochem
January 2025
Faculty of Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
SN1-type alkylating reagents generate O6-methylguanine (meG) lesions that activate the mismatch repair (MMR) response. Since post-replicative MMR specifically targets the nascent strand, meG on the template strand is refractory to rectification by MMR and, therefore, can induce non-productive MMR reactions. The cycling of futile MMR attempts is proposed to cause DNA double-strand breaks in the subsequent S phase, leading to ATR-checkpoint-mediated G2 arrest and apoptosis.
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