Melatonin has no effect on the growth, morphology or cell cycle of human breast cancer (MCF-7), cervical cancer (HeLa), osteosarcoma (MG-63) or lymphoblastoid (TK6) cells

Cancer Lett. 1998 Jan 9;122(1-2):17-23. doi: 10.1016/s0304-3835(97)00360-1.


Melatonin was previously shown to inhibit proliferation of MCF-7 human breast cancer cells. In this study the effect of melatonin on MCF-7 cells was further examined, while human cervical carcinoma (HeLa), osteosarcoma (MG-63) and lymphoblastoid (TK6) cells were tested for the first time. Haemocytometer counts, DNA content, flow cytometry and indirect immunofluorescence for nucleolar proteins, actin and beta-tubulin showed no differences in the growth, cell cycle or morphology between melatonin-exposed and control cells. The direct antiproliferative effect of melatonin thus seems to be confined to a melatonin-responsive subclone of MCF-7 cells and not applicable to the majority of cancer cells.

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Breast Neoplasms / pathology
  • Cell Cycle / drug effects
  • Cell Division / drug effects
  • DNA, Neoplasm / analysis
  • Dose-Response Relationship, Drug
  • Female
  • Flow Cytometry
  • HeLa Cells
  • Humans
  • Melatonin / pharmacology*
  • Osteosarcoma / pathology
  • Tumor Cells, Cultured


  • Antineoplastic Agents
  • DNA, Neoplasm
  • Melatonin