Both authors contributed equally to this manuscript.
Influence of the antifolate drug Methotrexate on the development of murine neural tube defects and genomic instability
Article first published online: 13 JUL 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Journal of Applied Toxicology
Volume 33, Issue 9, pages 915–923, September 2013
How to Cite
Zhao, J., Guan, T., Wang, J., Xiang, Q., Wang, M., Wang, X., Guan, Z., Xie, Q., Niu, B. and Zhang, T. (2013), Influence of the antifolate drug Methotrexate on the development of murine neural tube defects and genomic instability. J. Appl. Toxicol., 33: 915–923. doi: 10.1002/jat.2769
- Issue published online: 23 JUL 2013
- Article first published online: 13 JUL 2012
- Manuscript Accepted: 27 MAR 2012
- Manuscript Revised: 7 MAR 2012
- Manuscript Received: 29 APR 2011
- DNA copy number variations;
- neural tube defects
Impaired folate metabolism is considered a risk factor for neural tube defects (NTDs). However, the relationship between folate deficiency and the risk of NTDs remains unclear, because experimentally induced dietary folate deficiency is insufficient to cause NTDs in non-mutant mice. Methotrexate (MTX) is a specific folate antagonist that competitively inhibits dihydrofolate reductase (DHFR) activity. The objective of this study was to develop a folate dysmetabolism murine model, and study the development of NTDs and its mechanism. Pregnant mice were injected with different doses of MTX [0, 0.5, 1.0, 3.0, 4.5 and 6.0 mg kg–1 body weight (b/w) intraperitoneally (i.p.)] on gestational day 7.5 and sacrificed on gestational day 11.5. DHFR activity in embryonic tissues was detected, and folate concentrations were analyzed using LC/MS/MS. Copy number variations (CNVs) in neural tube tissues were detected using array comparative genomic hybridization (aCGH). A dose of MTX 4.5 mg kg–1 b/w, resulted in the highest incidence of NTDs (31.4%) compared with the other groups, and DHFR activities, 5-MeTHF and 5-FoTHF concentrations in embryonic tissues decreased significantly after MTX injection. Furthermore, we found three high-confidence CNVs on chromosome X using aCGH, which was confirmed by RT-PCR and MassARRAY. These results indicate that MTX could cause a folate-associated dysmetabolism, which is similar to that of dietary folate deficiency in mice. The presence of CNVs in neural tube tissues was associated with the development of NTDs. Copyright © 2012 John Wiley & Sons, Ltd.