Curcumin, a natural phenolic compound present in the rhizome of turmeric, is commonly used as a coloring agent in foods, drugs, and cosmetics and exhibits anti-inflammatory, anti-oxidant and anti-tumor activities. The four members of the epidermal growth factor receptor tyrosine kinase family is implicated in the genesis or progression of human cancers and the overexpression of ErbB2 is associated with a poor prognosis of breast cancer patients. The present study examined whether curcumin inhibits MCF-7 cell growth and whether such an effect is related to changes in the protein expression of ErbB receptor family. When MCF-7 cells were treated with different concentrations of curcumin, curcumin decreased viable cell numbers in a concentration dependent manner. Curcumin inhibited DNA synthesis, induced a G1 cycle arrest, and induced apoptosis in MCF-7 cells. Western blot analysis of total cell lysates revealed that curcumin decreased the protein levels of ErbB2 and ErbB3. Curcumin decreased the phosphorylation of ERK-1/2. These results indicate that downregulation of ErbB2-ErbB3- Erk-1/2 signaling may be one of the mechanisms by which curcumin inhibits MCF-7 cell proliferation and induces apoptosis.

Keywords: Curcumin, Breast cancer cell, ErbB2, Erk-1/2