Melatonin increases p53 and p21WAF1 expression in MCF-7 human breast cancer cells in vitro

Life Sci. 1999;65(4):415-20. doi: 10.1016/s0024-3205(99)00262-3.


The aim of the present work was to study whether melatonin, at physiological concentrations, exerts its antiproliferative effects on MCF-7 human breast cancer cells by inducing the expression of some of the proteins involved in the control of the cell cycle. MCF-7 cells were cultured for 48 h in DMEM media containing either melatonin (1 nM) or the diluent (0.001% ethanol). At this concentration, after 48 hours of incubation, melatonin reduced the number of viable cells in relation to controls. The decreased cell proliferation was coincident with a significant increase in the expression of p53 as well as p21WAF1 proteins. These results demonstrate that melatonin inhibits MCF-7 cell proliferation by inducing an arrest of cell cycle dependent on an increased expression of p21WAF1 protein, which is mediated by the p53 pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / metabolism*
  • Cell Cycle / drug effects
  • Cell Division / drug effects
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins / biosynthesis*
  • Female
  • Humans
  • Immunoenzyme Techniques
  • Melatonin / pharmacology*
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / metabolism
  • Tumor Suppressor Protein p53 / biosynthesis*


  • CDKN1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p21
  • Cyclins
  • Tumor Suppressor Protein p53
  • Melatonin