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. 1982 Oct;46(4):538–550. doi: 10.1038/bjc.1982.238

Accumulation of 125I-labelled thiouracil and propylthiouracil in murine melanotic melanomas.

B Larsson, K Olander, L Dencker, L Holmqvist
PMCID: PMC2011190  PMID: 7138763

Abstract

We have shown that thioamides are incorporated as false precursors into melanin during its synthesis. To be clinically useful in the diagnosis or therapy of melanotic melanomas, they would have to be tagged with an appropriate isotope or possibly a cytotoxic moiety. 125I-Thiouracil (125I-TU) is here shown to be accumulated in the melanin of melanotic melanomas transplanted into mice in a similar way as is 14C-thiouracil (14C-TU). 125I-TU gives tumour/liver and tumour/muscle ratios up to 22 and 778 respectively, at 4 days after administration. 125I-TU is accumulated by melanoma cells in vitro more effectively than 14C-TU (125I-TU/14C-TU, 2.7), while the in vivo accumulation into melanomas is slightly lower for 125I-TU as compared to 14C-TU (125I-TU/14C-TU, 0.35). This appears to be due to a partial deiodination (less than 14% of the dose within 4 days) and probably a more rapid excretion of 125I-TU or its metabolite(s). The accumulation of radioactivity in the thyroid can essentially be eliminated by pretreatment with potassium iodide and/or thyroxine. 125I-Propylthiouracil is also accumulated in melanotic melanoma cells in vivo and in vitro, but at a lower level than in 125I-TU and 14C-TU.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Beierwaltes W. H., Lieberman L. M., Varma V. M., Counsell R. E. Visualizing human malignant melanoma and metastases. Use of chloroquine analog tagged with iodine 125. JAMA. 1968 Sep 30;206(1):97–102. [PubMed] [Google Scholar]
  2. Blois M. S. Melanoma detection with radioiodoquine. J Nucl Med. 1968 Sep;9(9):492–493. [PubMed] [Google Scholar]
  3. Dencker L., Larsson B., Olander K., Ullberg S. A new melanoma seeker for possible clinical use: selective accumulation of radiolabelled thiouracil. Br J Cancer. 1982 Jan;45(1):95–104. doi: 10.1038/bjc.1982.12. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dencker L., Larsson B., Olander K., Ullberg S., Yokota M. False precursors of melanin as selective melanoma seekers. Br J Cancer. 1979 Apr;39(4):449–452. doi: 10.1038/bjc.1979.80. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dencker L., Larsson B., Olander K., Ullberg S., Yokota M. Incorporation of thiouracil and some related compounds into growing melanin. Acta Pharmacol Toxicol (Copenh) 1981 Aug;49(2):141–149. doi: 10.1111/j.1600-0773.1981.tb00883.x. [DOI] [PubMed] [Google Scholar]
  6. Dencker L., Lindquist N. G., Tjälve H. Uptake of 14C-labelled chloroquine and an 125I-labelled chloroquine analogue in some polypeptide hormone producing cell systems. Med Biol. 1976 Feb;54(1):62–68. [PubMed] [Google Scholar]
  7. Dencker L., Lindquist N. G., Ullberg S. Distribution of an 125I-labelled chloroquine analogue in a pregnant macaca monkey. Toxicology. 1975 Nov;5(2):255–265. doi: 10.1016/0300-483x(75)90122-5. [DOI] [PubMed] [Google Scholar]
  8. Meier D. A., Beierwaltes W. H., Counsell R. E. Radioactivity from labeled precursors of melanin in mice and hamsters with melanomas. Cancer Res. 1967 Aug;27(8):1354–1359. [PubMed] [Google Scholar]
  9. POTTS A. M. TRACER STUDIES ON A TRANSPLANTABLE HAMSTER MELANOMA. Arch Ophthalmol. 1964 Sep;72:359–364. doi: 10.1001/archopht.1964.00970020359014. [DOI] [PubMed] [Google Scholar]
  10. Packer S., Redvanly C., Lambrecht R. M., Wolf A. P., Atkins H. L. Quinoline analog labeled with iodine 123 in melanoma detection. Arch Ophthalmol. 1975 Jul;93(7):504–508. doi: 10.1001/archopht.1975.01010020520007. [DOI] [PubMed] [Google Scholar]
  11. ROSELL S., SEDVALL G., ULLBERG S. Distribution and fate of dihydroxyphenylalanine-2-14C (DOPA) in mice. Biochem Pharmacol. 1963 Mar;12:265–269. doi: 10.1016/0006-2952(63)90149-7. [DOI] [PubMed] [Google Scholar]
  12. Safi N., Blanquet P. Apport des molécules marquées au diagnostic et á la surveillances des tumeurs mélaniques. Biomedicine. 1973 Mar 20;19(3):122–125. [PubMed] [Google Scholar]
  13. Walsh T. J., Packer S. Radioisotope detection of ocular melanomas. N Engl J Med. 1971 Feb 11;284(6):317–318. doi: 10.1056/NEJM197102112840608. [DOI] [PubMed] [Google Scholar]
  14. Whittaker J. R. Biosynthesis of a thouracil pheomelanin in embryonic pigment cells exposed to thouracil. J Biol Chem. 1971 Oct 25;246(20):6217–6226. [PubMed] [Google Scholar]

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