Hormonal effects

• Stimulate cell proliferation through hormonal effect
• Growth hormones = Mitogens --> bind to Membrane + Intracellular signal transmission protein receptors --> increase cell proliferation
• TPA (tumor promoter) --> bind to Protein Kinase C (involved in signalling transmission) --> stimulate Mitogenic pathways
• If an initiating mutation in a gene (e.g., proto-oncogene) enhances responsiveness to growth stimulation by a growth factor --> promoter might induce proliferation selectively in those initiated cells
• • Estrogen and estrogenic-mimetic chemicals: induce tumors in estrogen- dependent tissue
  • Studies on breast and ovarian cancer: individuals with high circulating estrogen levels + exposure to diethylstilbestrol (DES) (a synthetic form of estrogen) = increased risk of cancer development
  • DES was prescribed to pregnant women during 1940 - 1971 to prevent miscarriage and premature labor