Anti-leukaemic effects of two extract types of Lactuca sativa correlate with the activation of Chk2, induction of p21, downregulation of cyclin D1 and acetylation of alpha-tubulin

Oncol Rep. 2010 Apr;23(4):1145-51. doi: 10.3892/or_00000744.


The water extract of the lettuce Lactuca sativa, but not the ethyl acetate extract, inhibited the growth of HL-60 leukaemia cells and MCF-7 breast cancer cells. This correlated with the activation of checkpoint kinase 2 (Chk2), the induction of the tumour suppressor p21, and the severe downregulation of the proto-oncogene cyclin D1. The ethyl acetate extract, but not the water extract, induced HL-60 cell death, which correlated with the acetylation of alpha-tubulin. The acetylation of alpha-tubulin is indicative for microtubuli stabilisation such as induced by taxol. The calculated amount for human intake would require approximately 3 kg lettuce to reach the required concentration shown to inhibit 50% HL-60 proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Antineoplastic Agents, Phytogenic / pharmacology*
  • Blotting, Western
  • Cell Cycle Proteins / drug effects*
  • Cell Cycle Proteins / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects*
  • Checkpoint Kinase 2
  • Cyclin D1 / drug effects
  • Cyclin D1 / metabolism
  • Cyclin-Dependent Kinase Inhibitor p21 / drug effects
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism
  • Down-Regulation
  • Humans
  • Lettuce / chemistry*
  • Plant Extracts / pharmacology*
  • Protein-Serine-Threonine Kinases / drug effects
  • Protein-Serine-Threonine Kinases / metabolism
  • Tubulin / drug effects
  • Tubulin / metabolism


  • Antineoplastic Agents, Phytogenic
  • Cell Cycle Proteins
  • Cyclin-Dependent Kinase Inhibitor p21
  • Plant Extracts
  • Tubulin
  • Cyclin D1
  • Checkpoint Kinase 2
  • CHEK2 protein, human
  • Protein-Serine-Threonine Kinases