Centchroman induces G0/G1 arrest and caspase-dependent apoptosis involving mitochondrial membrane depolarization in MCF-7 and MDA MB-231 human breast cancer cells

Life Sci. 2008 Mar 12;82(11-12):577-90. doi: 10.1016/j.lfs.2007.11.028. Epub 2007 Dec 15.


Studies with Centchroman (CC) as a candidate anti-breast cancer agent are into phase III multicentric clinical trial in stage III/IV breast cancer. We have previously demonstrated its anti-neoplastic activity in Estrogen Receptor positive (ER+ve) MCF-7 Human Breast Cancer Cells (HBCCs). We now present the basis for anti-neoplastic activity of CC, mediated through apoptosis in both ER+ve/-ve MCF-7 and MDA MB-231 HBCCs respectively, compared to Tamoxifen (TAM) as a positive control. All the experiments were performed with 48 h estrogen-deprived cells exposed to CC/TAM for the subsequent 48 h. Cytotoxic potential of CC was assessed through SRB assay. Cell-cycle analysis, Time-dependent cytotoxicity, Reactive Oxygen Species (ROS) and Mitochondrial Membrane Permeability were investigated by Flow Cytometry. Early-stage apoptosis was detected by Annexin-PI staining. Caspases were assayed colorimetrically whereas nuclear derangements were assessed morphologically through PI staining and finally by DNA fragmentation analysis. Cell viability studies confirmed the IC50 of CC in MCF-7 and MDA MB-231 cells to be 10 and 20 microM (P < 0.001) respectively, suggesting enhanced susceptibility of the former cell type to CC. FACS data reveals CC mediated G0/G1 arrest (P < 0.01) along with the presence of prominent sub-G0/G1 peak (P < 0.001) in both the cell types suggesting ongoing apoptosis. Phosphatidylserine externalization, mitochondrial events, caspase evaluation and nuclear morphology changes reveal initiation/progression of caspase-dependent apoptosis even at a dose of 1 microM which eventually leads to DNA fragmentation in both the cell types. Results demonstrate that CC induces caspase-dependent apoptosis in MCF-7 and MDA MB-231 cells irrespective of ER status similar to TAM in terms of anti-neoplastic activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Breast Neoplasms
  • Caspases / metabolism*
  • Cell Line, Tumor
  • Cell Nucleus / ultrastructure
  • Cell Shape
  • Cell Survival / drug effects
  • Centchroman / pharmacology*
  • Clinical Trials as Topic
  • DNA Fragmentation
  • Estrogen Antagonists / pharmacology*
  • Female
  • G1 Phase / drug effects*
  • Humans
  • Membrane Potentials / physiology
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Resting Phase, Cell Cycle / drug effects*
  • Tamoxifen / pharmacology


  • Antineoplastic Agents
  • Estrogen Antagonists
  • Tamoxifen
  • Centchroman
  • Caspases