Planta Med 2009; 75(13): 1423-1426
DOI: 10.1055/s-0029-1185805
© Georg Thieme Verlag KG Stuttgart · New York

The Phytohormone Auxin Induces G1 Cell-Cycle Arrest of Human Tumor Cells

Katja Ester1 , Mirna Ćurković-Perica2 , Marijeta Kralj1
  • 1Division of Molecular Medicine, Rudjer Boskovic Institute, Zagreb, Croatia
  • 2Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
Further Information

Publication History

received March 5, 2009 revised May 11, 2009

accepted May 14, 2009

Publication Date:
22 June 2009 (online)


The plant hormone auxin is the key regulator of plant growth and development. Auxin regulates transcription of plant genes by targeting degradation of transcriptional repressor proteins Aux/IAA. While there are many reports describing its potential to modulate human cell functions, the majority are based on auxin action following enzymatic activation. A study focused on auxin alone and its antiproliferative potential, with emphasis on modulation of the cell cycle, has not been performed. Therefore, we analyzed tumor growth inhibitory effects and the cell-cycle perturbations of natural (IAA, IBA) and synthetic (NAA, 2,4-D) auxins. All derivatives showed cytostatic effects on selected human tumor cell lines. The cell-cycle analysis revealed that IAA and 2,4-D induce strong G1 arrest, along with a drastic decrease in the percentage of S-phase cells in MCF-7 cell line. This phenomenon demonstrates that auxins may have novel, unexploited antitumor potential and should be further investigated.


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Dr. sc. Katja Ester

Rudjer Boskovic Institute

Division of Molecular Medicine

Bijenicka 54

10002 Zagreb


Phone: + 3 85 14 57 12 35

Fax: + 3 85 14 56 10 10