Curcumin, oxidative stress, and breast cancer

Breast cancer is the most frequently diagnosed malignancy in women in the western world. Oxidative stress is one of the important pathogenic factors of cancer development. Among the antioxidants, curcumin (1, 7-bis (4-hydroxy-3-methoxyphenyl)-1, 6-heptadiene-3, 5-dione; diferuloylmethane) is a dietary natural yellow pigment derived from the rhizome of the herb Curcuma longa (Zingiberaceae). This study evaluated the effects of curcumin on oxidative stress in an established in vitro experimental breast cancer model (Alpha-model) as well as in isolated cells derived from breast specimens. Such model was developed with the immortalized breast cell line, MCF-10F, that was exposed to low doses of high linear energy transfer (LET) α particles (150keV/µm) of radiation, values comparable to α particles emitted by radon progeny, and cultured in the presence of 17β-estradiol. It consisted of cell lines in different stages of transformation: (i) MCF-10F, (ii) an estrogen-treated, called Estrogen, (iii) a malignant one, called Alpha3, (iv) a malignant and tumorigenic one, called Alpha5, and (v) a tumor cell line, called Tumor2 derived from a tumor after injection of previous one in nude mice. Free radical production is ubiquitous in all organisms and it is enhanced in many diseases. Curcumin interferes with multiple genes that promote carcinogenesis, thereby affecting genomic instability. Alteration in protein expressions involved in key signaling pathways and epithelial-mesenchymal transition render this model an important tool for monitoring effects of natural dietary compounds in breast carcinogenesis.