Researchers at East Carolina University and report for the first time the microRNA expression profile of human breast cancer MCF-7 cells and the effect of green tea. microRNA Microarray identified twenty three miRNAs that exhibit differential expression after a 48 h treatment with 10 μg/ml Polyphenon-60 (green tea extract).
These miRNAs include miR-21 and miR-27 that were found to be down-regulated following treatment with green tea. These two miRNAs have previously been identified as being overexpressed in MCF-7 breast cancer cells, with miR-21 specifically implicated in down-regulating the tumor suppressor gene, tropomyosin-1.
This data supports the hypothesis that Polyphenon-60-induced modification of the breast cancer miRNA expression profile contributes to the efficacy of green tea treatment. The resulting decrease in carcinogenesis is further supported by the altered miRNA regulation of potential oncogenes and tumor-suppressor genes.
Fix N, Shah M, Efferth T, Farwell M, Zhang B. (2010) MicroRNA Expression Profile of MCF-7 Human Breast Cancer Cells and the Effect of Green Tea Polyphenon-60. Cancer Genomics & Proteomics 7(5), 261-277. [abstract]