Abstract
Dihydropyrimidine dehydrogenase (DPD), the initial, rate-limiting step in pyrimidine degradation, was studied in two cell lines of murine neuroblastoma (MNB-T1 and MNB-T2) that were derived from C-1300 MNB tumor carried in A/J mice. The MNB-T2 (low malignancy) cell line was originally derived from the in situ tumor and carried in tissue culture for more than 100 passages; the MNB-T1 (high malignancy) line consisted of a new sub-culture that was also established from the in situ MNB tumor. DPD activity was determined in cytosolic preparations of MNB utilizing high performance liquid chromatography to separate the radiolabeled substrate ([2-14C]thymine) from [2-14C]dihydrothymine. The apparent affinity of DPD for NADPH in MNB cells (Km approximately 0.08 mM) was identical to that of A/J mouse brain and liver. The DPD activity of the high malignancy (MNB-T1) cell line was 14.3% of that observed in the low malignancy (MNB-T2) line. In situ tumors formed after implantation of high malignancy (MNB-T1) cells into A/J mice had only 25.2% of the DPD activity observed in tumors derived from low malignancy (MNB-T2) cells. When MNB-T2 cells were injected into naive A/J mice, tumors developed in only 68% of animals, the tumor growth rate was slow and a mortality of 20% was observed. In contrast, tumors derived from injected MNB-T1 cells showed a faster growth rate and 100% mortality. Most MNB-T2 derived tumors were not lethal and ultimately resolved while the MNB-T1 derived tumors were invariably lethal. These studies support the concept that the levels of DPD activity in neoplastic cells are inversely related to their malignant expression and also provide a model to study differences between neuroblastoma cell lines derived from the same in situ tumor but which manifest different neoplastic behavior.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- CANELLAKIS E. S. Pyrimidine metabolism. I. Enzymatic pathways of uracil and thymine degradation. J Biol Chem. 1956 Jul;221(1):315–322. [PubMed] [Google Scholar]
- CARAVACA J., GRISOLIA S. Enzymatic decarbamylation of carbamyl beta-alanine and carbamyl beta-aminoisobutyric acid. J Biol Chem. 1958 Mar;231(1):357–365. [PubMed] [Google Scholar]
- FINK R. M., FINK K., HENDERSON R. B. beta-amino acid formation by tissue slices incubated with pyrimidines. J Biol Chem. 1953 Mar;201(1):349–355. [PubMed] [Google Scholar]
- FRITZSON P. Properties and assay of dihydrouracil dehydrogenase of rat liver. J Biol Chem. 1960 Mar;235:719–725. [PubMed] [Google Scholar]
- Ferdinandus J. A., Morris H. P., Weber G. Behavior of opposing pathways of thymidine utilization in differentiating, regenerating, and neoplastic liver. Cancer Res. 1971 May;31(5):550–556. [PubMed] [Google Scholar]
- GRISOLIA S., CARDOSO S. S. The purification and properties of hydropyrimidine dehydrogenase. Biochim Biophys Acta. 1957 Aug;25(2):430–431. doi: 10.1016/0006-3002(57)90498-5. [DOI] [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Naguib F. N., el Kouni M. H., Cha S. Enzymes of uracil catabolism in normal and neoplastic human tissues. Cancer Res. 1985 Nov;45(11 Pt 1):5405–5412. [PubMed] [Google Scholar]
- Pons G., O'Dea R. F., Mirkin B. L. Biological characterization of the C-1300 murine neuroblastoma: an in vivo neural crest tumor model. Cancer Res. 1982 Sep;42(9):3719–3723. [PubMed] [Google Scholar]
- Queener S. F., Morris H. P., Weber G. Dihydrouracil dehydrogenase activity in normal, differentiating and regnerating liver and in hepatomas. Cancer Res. 1971 Jul;31(7):1004–1009. [PubMed] [Google Scholar]
- Shiotani T., Weber G. Purification and properties of dihydrothymine dehydrogenase from rat liver. J Biol Chem. 1981 Jan 10;256(1):219–224. [PubMed] [Google Scholar]
- Smith A. E., Yamada E. W. Dihydrouracil dehydrogenase of rat liver. Separation of hydrogenase and dehydrogenase activities. J Biol Chem. 1971 Jun 10;246(11):3610–3617. [PubMed] [Google Scholar]
- Traut T. W., Loechel S. Pyrimidine catabolism: individual characterization of the three sequential enzymes with a new assay. Biochemistry. 1984 May 22;23(11):2533–2539. doi: 10.1021/bi00306a033. [DOI] [PubMed] [Google Scholar]
- Tuchman M., Ramnaraine M. L., O'Dea R. F. Effects of uridine and thymidine on the degradation of 5-fluorouracil, uracil, and thymine by rat liver dihydropyrimidine dehydrogenase. Cancer Res. 1985 Nov;45(11 Pt 1):5553–5556. [PubMed] [Google Scholar]
- WALLACH D. P., GRISOLIA S. The purification and properties of hydropyrimidine hydrase. J Biol Chem. 1957 May;226(1):277–288. [PubMed] [Google Scholar]
- Wasternack C. Degradation of pyrimidines and pyrimidine analogs--pathways and mutual influences. Pharmacol Ther. 1980;8(3):629–651. doi: 10.1016/0163-7258(80)90079-0. [DOI] [PubMed] [Google Scholar]
- Weber G., Olah E., Denton J. E., Lui M. S., Takeda E., Tzeng D. Y., Ban J. Dynamics of modulation of biochemical programs in cancer cells. Adv Enzyme Regul. 1980;19:87–102. doi: 10.1016/0065-2571(81)90010-8. [DOI] [PubMed] [Google Scholar]