Effects of bamboo extract on breast cancer

Breast cancer is the most common cancer among women in the United States, and worldwide over one million new cases are diagnosed each year. Preliminary studies by Panee and colleagues demonstrated that 0.5% (w/w) dietary supplementation with an ethanol/water extract from bamboo Phyllostachys edulis inhibited the incidence of 7,12‐dimethylbenz[a]anthracene (DMBA, a carcinogen)‐induced mammary tumors in female Sprague‐Dawley rats by 44% and dramatically reduced tumor multiplicity. This project has aimed to delineate the anti‐breast cancer mechanisms of this bamboo extract (BEX) in the aforementioned rat model. We hypothesized that BEX may alter the gene expression of key proteins involved in estrogen‐ and/or growth factor‐signaling pathways and xenobiotic biotransforming enzymes in the mammary tumors. To test this hypothesis, we extracted RNA from individual mammary tumors that were harvested from each rat. Then, we synthesized complementary DNA (cDNA) and combined the cDNA samples according to each rat9s dietary group— BEX‐supplemented rat diet or control rat diet. Using quantitative real‐time polymerase chain reaction, we measured expression levels of target genes that included the following: estrogen receptors alpha and beta (ER‐α and ‐β), human epidermal growth factor receptor 2 (HER2), and all glutathioine‐s‐transferase (GST) isoforms. Comparison between study groups revealed that BEX‐supplementation significantly downregulated the gene expression of ER‐α, ER‐β, and HER2 in the mammary tumors by 65%, 70%, and 67% respectively (p Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B155.