Immunological and mass spectrometry-based approaches to determine thresholds of the mutagenic DNA adduct O6-methylguanine in vivo.

Immunological and mass spectrometry-based approaches to determine thresholds of the mutagenic DNA adduct O6-methylguanine in vivo. Arch Toxicol. 2018 Nov 16;: Authors: Kraus A, McKeague M, Seiwert N, Nagel G, Geisen SM, Ziegler N, Trantakis IA, Kaina B, Thomas AD, Sturla SJ, Fahrer J Abstract N-nitroso compounds are alkylating agents, which are widespread in our diet and the environment. They induce DNA alkylation adducts such as O6-methylguanine (O6-MeG), which is repaired by O6-methylguanine-DNA methyltransferase (MGMT). Persistent O6-MeG lesions have detrimental biological consequences like mutagenicity and cytotoxicity. Due to its pivotal role in the etiology of cancer and in cytotoxic cancer therapy, it is important to detect and quantify O6-MeG in biological specimens in a sensitive and accurate manner. Here, we used immunological approaches and established an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to monitor O6-MeG adducts. First, colorectal cancer (CRC) cells were treated with the methylating anticancer drug temozolomide (TMZ). Immunofluorescence microscopy and an immuno-slot blot assay, both based on an adduct-specific antibody, allowed for the semi-quantitative, dose-dependent assessment of O6-MeG in CRC cells. Using the highly sensitive and specific UPLC-MS/MS, TMZ-induced O6-MeG adducts were quantified in CRC cells and even in peripheral blood mononuclear cells exposed to clinically ...
Source: Archives of Toxicology - Category: Toxicology Authors: Tags: Arch Toxicol Source Type: research