This chapter presents a systematic analysis of the effects of a mitogenic hormone, 17β-estradiol (E2), and its antagonist or antihormone, tamoxifen (tam), on the incorporation of various precursors into the DNA in the Michigan Cancer Foundation-7 (MCF-7) human breast cancer cell line. These experiments logically followed initial demonstrations that E2 and tam, respectively, stimulated and inhibited the growth of these cells in vivo and in vitro. The chapter also discusses the conditions for the valid use of [3H]dThd incorporation in measuring the scavenger (salvage) pathway. The results are compared to measurements of net DNA synthesis as monitored by ortho [32P]phosphate incorporation into purified DNA. The chapter discusses the development of an assay for de novo pyrimidine biosynthesis. These experiments are useful for establishing the effects of virtually any mitogen on pyrimidine nucleotide pool size, salvage, or de novo synthesis.
ASJC Scopus subject areas
- Molecular Biology