These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Azidothymidine and dipyridamole as biochemical response modifiers: synergism with methotrexate and 5-fluorouracil in human colon and pancreatic carcinoma cells.
    Author: Zhen YS, Taniki T, Weber G.
    Journal: Oncol Res; 1992; 4(2):73-8. PubMed ID: 1596584.
    Abstract:
    Azidothymidine (AZT), inhibiting thymidine kinase (EC 2.7.1.21) (Weber, G. et al., Cancer Commun. 2:129-133, 1990) and dipyridamole, inhibiting nucleoside transport (Zhen, Y.-s. et al., Cancer Res. 43:1616-1619, 1983) exert blocking action on the activities of salvage pathways of nucleotide biosynthesis. Determined by clonogenic assay in human colon cancer HT-29 cells, the cell survivals for AZT, 10 microM, dipyridamole, 5 microM, and methotrexate (MTX), 0.025 microM, were 90, 82, and 62%, respectively; while the combinations of AZT + MTX, dipyridamole + MTX and AZT + dipyridamole + MTX, reduced survivals to 36, 4.3, and 0.7%. AZT or dipyridamole was synergistic with MTX, whereas AZT plus dipyridamole showed an even more marked potentiation of MTX activity. The survivals for 5-fluorouracil (5-FU), 0.5 microM, alone, AZT + 5-FU, dipyridamole + 5-FU, and AZT + dipyridamole + 5-FU were 86, 47, 29 and 5.1%, respectively. Similar results were observed in human pancreatic carcinoma BxPC-3 and PANC-1 cells. AZT markedly enhanced the inhibitory effect of dipyridamole in reversing the thymidine-hypoxanthine rescue from MTX cytotoxicity. AZT inhibited [14C]thymidine incorporation into DNA in HT-29 cells and strongly enhanced the effect of dipyridamole. The results indicate that combinations composed of AZT, dipyridamole, and antimetabolites, such as MTX and 5-FU, are potentially effective in the chemotherapy of human neoplasias.
    [Abstract] [Full Text] [Related] [New Search]