Abstract
Mouse neuroblastoma cells, NB, have been grown in increasing concentrations of mycophenolic acid for greater than 80 passages. A mycophenolic acid resistant neuroblastoma cell line (NB-MyR) has been isolated which is 1000-fold more resistant to mycophenolic acid than NB cells. Fifty percent growth inhibition was caused by 1.6 × 10−7 M and 1.65 × 10−4 M mycophenolic acid for NB and NB-MyR cells respectively. In crude cell lysates the apparant inhibition constant for mycophenolic acid with inosinate dehydrogenase was 6 × 10−8 M and 14 × 10−8 M for NB and NB-MyR cells respectively. Thus the ki for mycophenolic acid was essentially unchanged. The specific activity of inosinate dehydrogenase was 4.9 ± 1.4 and 26.6 ± 2.5 nmole/min/mg protein for NB and NB-MyR cells respectively. The 5.4-fold increase of inosinate dehydrogenase activity in the NB-MyR line may account in part for the increased resistance to mycophenolic acid. Preliminary findings also suggest a 3-fold increase in guanylate synthetase activity for NB-MyR cells as compared to NB cells.
Supported by the Alberta Cancer Board grant H-105
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hodges, S., O'brien, S., Lin, C. et al. INCREASED INOSINATE DEHYDROGENASE ACTIVITY IN MYOPHENOLIC ACID RESISTANT NEUROBLASTOMA CELLS: 88. Pediatr Res 19, 758 (1985). https://doi.org/10.1203/00006450-198507000-00108
Issue Date:
DOI: https://doi.org/10.1203/00006450-198507000-00108