Immunohistochemical expression of RARα, RARβ, and Cx43 in breast tumor cell lines after treatment with lycopene and correlation with RT-QPCR

Lycopene, the major carotenoid found in tomatoes, is a potent antioxiclant associated with the prevention of degenerative diseases such as breast cancer. This effect could be due to the interaction between lycopene and retinoic acid receptors as well as the stimulation of gap junction communication and synthesis of connexin 43. The expression of the RARa, RARP, and Cx43 proteins was analyzed using immunohistochemistry in two breast cancer cell lines, MCF-7 and MDA-MB-231, and in a fibrocystic dystrophy cell line, MCF-10a, after a 48-hr exposure to 10 mu M lycopene. A real-time quantitative PCR analysis was then performed to measure mRNA expression. RARa and Cx43 expression were increased at both mRNA and protein levels in two breast cell lines.