Decreased thymosin beta4 in apoptosis induced by a variety of antitumor drugs

Biochem Pharmacol. 1999 May 15;57(10):1105-11. doi: 10.1016/s0006-2952(99)00030-1.


As many antitumor drugs can kill tumors through the induction of apoptosis, the effect of these drugs presumably would be enhanced if they were used in combination with other drugs that interact with apoptotic processes. To clarify the biological events involved in the induction of apoptosis, we examined changes in the proteins associated with induction of apoptosis by antitumor drugs. When Molt-4 cells were exposed to the antitumor drugs etoposide, meso-2,3-bis(3,5-dioxopiperazine-1-yl)butane (ICRF-193), and neocarzinostatin, they exhibited apoptotic cell death as determined by flow cytometry using fluorescein isothiocyanate (FITC)-labeled annexin V staining of phosphatidylserine on membranes and detection of hypodiploid cells. Following the induction of apoptosis, a low molecular weight protein that was identified to be thymosin beta4 by HPLC analysis was commonly decreased, and the morphology of actin filaments changed into clump formations. These results suggest that decreased thymosin beta4 is involved in the induction of apoptosis by antitumor drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / chemistry
  • Actins / drug effects
  • Amino Acid Sequence
  • Antineoplastic Agents / pharmacology*
  • Apoptosis*
  • Cell Division / drug effects
  • Diketopiperazines
  • Etoposide / pharmacology
  • Humans
  • Molecular Sequence Data
  • Neoplasm Proteins / metabolism
  • Piperazines / pharmacology
  • Sequence Homology, Amino Acid
  • Thymosin / metabolism*
  • Tumor Cells, Cultured
  • Zinostatin / pharmacology


  • Actins
  • Antineoplastic Agents
  • Diketopiperazines
  • Neoplasm Proteins
  • Piperazines
  • 4,4'-(1,2-dimethyl-1,2-ethanediyl)bis-2,6-piperazinedione
  • thymosin beta(4)
  • Thymosin
  • Etoposide
  • Zinostatin