Surfactin Induces Apoptosis and G2/M Arrest in Human Breast Cancer MCF-7 Cells Through Cell Cycle Factor Regulation

  • Xiaohong Cao
  • A. H. Wang
  • R. Z. Jiao
  • C. L. Wang
  • D. Z. Mao
  • L. Yan
  • B. Zeng
Original Paper

DOI: 10.1007/s12013-009-9065-4

Cite this article as:
Cao, X., Wang, A.H., Jiao, R.Z. et al. Cell Biochem Biophys (2009) 55: 163. doi:10.1007/s12013-009-9065-4

Abstract

Surfactin, purified from Bacillus subtilis natto TK-1, inhibited proliferation of human breast cancer MCF-7 cells in a dose- and time-dependent manner, with IC50 at 24, 48, and 72 h of 82.6, 27.3, and 14.8 μM, respectively. Surfactin-induced cell death was considered to be apoptotic by observing the typical apoptotic morphological change by acridine orange/ethidium bromide staining and Transferase-mediated dUTP Nick End-labeling assay. [Ca2+]i measurement revealed that surfactin induced a sustained increase in concentration of intracellular [Ca2+]i. Flow cytometric analysis also demonstrated that surfactin caused time-dependent apoptosis of MCF-7 cells through cell arrest at G2/M phase. Western blot revealed that surfactin induced accumulation of the tumor suppressor p53 and cyclin kinase inhibitor p21waf1/cip1, and inhibited the activity of the G2-specific kinase, cyclin B1/p34cdc2. Based on our findings, surfactin inhibited proliferation in MCF-7 cells by inducing apoptosis and the elevation of [Ca2+]i may play an important role in the apoptosis. The mechanism which surfactin caused G2/M arrest seems to be through cell cycle factor regulation.

Keywords

Surfactin Bacillus subtilis natto TK-1 Anti-tumor Apoptosis AO/EB staining TUNEL [Ca2+]i Cell cycle 

Copyright information

© Humana Press Inc. 2009

Authors and Affiliations

  • Xiaohong Cao
    • 1
  • A. H. Wang
    • 1
  • R. Z. Jiao
    • 1
  • C. L. Wang
    • 1
  • D. Z. Mao
    • 1
  • L. Yan
    • 1
  • B. Zeng
    • 1
  1. 1.Key Laboratory of Food Safety and Sanitation, Ministry of Education, College of food Engineering and BiotechnologyTianjin University of Science and TechnologyTianjinChina