Increased thymidylate synthase (EC activity in normal and neoplastic proliferation

Cancer Biochem Biophys. 1988 Jul;10(1):1-10.


Thymidylate (dTMP) synthase (EC activity was measured in 100,000 x g supernatant fluid with a sensitive, rapid radio assay. The activity in normal rat liver was low (0.098-0.204 nmol/hr/mg protein). dTMP synthase specific activities in rat thymus, spleen, bone marrow, testis, lung, heart, brain, kidney, and small intestine were 6297, 1842, 1500, 788, 215, 76, 61, 39 and 24%, respectively, of that of the liver. The activity in 5-day-old rat liver was 16-fold higher than in adult. dTMP synthase activity increased in rat hepatomas to 7- to 125-fold of that of normal rat liver. There was a significant correlation between the increase in synthase activity and the proliferation rates of the hepatomas. In 8 human colon carcinomas, dTMP synthase activity increased to 2.9- to 8-fold of that of normal human colon mucosa. In leukemic leukocytes from 3 leukemia patients, activity was 8- to 10-fold higher than in normal leukocytes.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging
  • Animals
  • Cell Transformation, Neoplastic*
  • Colon / enzymology
  • Colonic Neoplasms / enzymology
  • Cytosol / enzymology
  • Humans
  • Intestinal Mucosa / enzymology
  • Kinetics
  • Leukemia / enzymology
  • Leukocytes / enzymology
  • Liver / enzymology*
  • Liver / growth & development
  • Liver Neoplasms, Experimental / enzymology*
  • Male
  • Organ Specificity
  • Rats
  • Reference Values
  • Thymidylate Synthase / metabolism*


  • Thymidylate Synthase