Methotrexate induced apoptotic and necrotic chromatin changes in rat myeloid leukemia cells
- 207 Downloads
It was tested as to why low-dose methotrexate (MTX) effective against rheumatoid arthritis poses considerable health risk at higher doses.
The tumorigenic potential of My1/De blast cells was followed by cytology and by the kinetics of 18FDG uptake. The toxicity of MTX on chromatin condensation was compared to predictive normal intermediates of chromosome condensation in control cells.
MTX below 0.1 µg/ml did not cause visible changes in interphase chromatin structure. At its lowest toxic concentration (0.1 µg/ml) chromatin margination was confined to the outer edge of the nucleus. Between 0.1 and 5 µg/ml concentrations apoptotic chromatin shrinkage correlated with the dose of MTX. Apoptosis was exerted in early S phase excluding the mitotic effect. At higher MTX concentrations (>10 µg/ml) necrotic disruption and expansion took place. The lowest necrotic concentration (10 µg/ml) was close to highest apoptotic MTX concentration (5 µg/ml).
The switch from apoptosis to inflammatory necrosis taking place within a narrow concentration range supports the notion of a narrow therapeutic spectrum. Chromatin changes are early markers of genotoxicity at much lower concentrations than citogenetic changes in properly chosen sensitive cells.
KeywordsLeukemia Cell death Reversible permeabilization Fluorescence microscopy Chromatin structure
This work was supported by Hungarian Scientific Research Fund (OTKA grant) T42762 grant to G.B.
- 3.Whitehead VM, Vuchich MJ, Cooley L, Lauer SJ, Mahoney DH, Shuster JJ, Payment C, Bernstein ML, Akabutu JJ, Bowen T, Kamen BA, Watson MS, Look AT, Pullen D, Camitta B. Translocations involving chromosome 12p11-13, methotrexate metabolism, and outcome in childhood B-progenitor cell acute lymphoblastic leukemia: a Pediatric Oncology Group study. Clin Cancer Res. 1998;4:183–8.PubMedGoogle Scholar
- 21.Banfalvi G. Apoptotic chromatin changes. Dordrecht: Springer Science and Business Media B.V.; (2009). pp. 125–202.Google Scholar
- 26.Rahiem Ahmed YAA, Hasan Y. Prevention and management of high-dose methotrexate toxicity. J Cancer Sci Ther. 2013;5:106–112.Google Scholar
- 35.Morgan SL, Baggott JE, Bernreuter WK, Gay RE, Arani R, Alarcón GS. MTX affects inflammation and tissue destruction differently in the rat AA model. J Rheumatol. 2011;28:1476–81.Google Scholar