Abstract
Differential expression of DNA-O 6MeG: protein-l-cysteine S-methyltransferase (MGMT) acti- vity and posttranslational modification of the pro- tein during liver regeneration and carcinogenesis were compared in Sprague-Dawley male rats after partial hepatectomy and/or single i.p injection of diethylnitrosamine (DEN, 200 mg/kg). Regenerating hepatocytes after partial hepatectomy induced MGMT transiently within 3 days; however, the induction of MGMT was persistent for 2 weeks after DEN injection, and the combined treatment of DEN and partial hepatectomy maintained the elevated MGMT level for up to 4 weeks. The increased activity was transcriptionally regulated, when analyzed by Northern blot hybridization. The major active form of MGMT protein in the partially hepatectomized or DEN-treated rats was a 26-kDa or 24-kDa species respectively, which was confirmed by Western blot analysis and gel slice assay. The biological significance of the differential induction of MGMT during partial hepatectomy or DEN-induced carcinogenesis is not obvious; however, further studies on possible posttranslational modifications of MGMT protein might shed some light on the functional aspect of MGMT induction.
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Received: 3 February 1999 / Accepted: 15 February 1999
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Lim, I., Park, T., Jee, J. et al. Differential expression of O 6-methylguanine-DNA methyltransferase during diethylnitrosamine-induced carcinogenesis and liver regeneration in Sprague-Dawley male rats. J Cancer Res Clin Oncol 125, 493–499 (1999). https://doi.org/10.1007/s004320050307
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DOI: https://doi.org/10.1007/s004320050307