Pomegranate fruit and juice have been shown to have various anti-breast cancer activities. The chemopreventive properties of pomegranate appear to be due to the actions of pomegranate components such as ellagic acid, punicic acid, ursolic acid, luteolin, and several anthocyanin pigments. Pomegranate fruit and extracts have been shown to exert antiproliferative effects on human breast cancer cells, including hormone receptor positive (ER+/PR+), triple negative, and HER2 overexpressing (HER2+) cells. Now a new study has reported that pomegranate extract reduces expression of genes involved in breast cancer proliferation.
Latest research finds pomegranate reduces breast cancer-related gene transcription
The study referenced at the beginning of this news article was designed to investigate whether pomegranate exerts its cytotoxic and anti-inflammatory activities, at least in part, by reducing certain specificity protein (Sp) transcription factors. Each gene encodes a unique protein that performs a specific function in cells. Cells use a two-step process of transcription and translation to read the gene and produce its protein. Gene transcription is the process by which genetic information is copied from DNA to mRNA. This is followed by translation, in which the mRNA is read and a specific protein is produced. Transcription factors are proteins that control the transcription of genetic information from DNA to mRNA by binding to specific DNA sequences. There is growing evidence that overexpression of certain Sp transcription factors, which regulate genes important for cancer cell survival and inflammation, are associated with breast cancer.
Pomegranate extract was found to inhibit the growth of HER2+ (BT474) and triple negative (MDA-MB-231) breast cancer cells but not normal breast cells. Pomegranate extract also significantly reduced Sp1, Sp3, and Sp4, as well as miR-27a, in HER2+ and triple negative cells and heightened the expression of the transcriptional repressor ZBTB10. A significant reduction in Sp proteins and Sp-regulated genes was also seen. Pg extract also induced SHIP-1 expression and this was accompanied by downregulation of miRNA-155 and inhibition of PI3K-dependent phosphorylation of AKT.
The authors also conducted studies using mice bearing BT474 tumors and treated with pomegranate extract. Similar results were observed in tumors from the mice. Further experimentation confirmed that the anti-inflammatory and cytotoxic effects of pomegranate were caused, in part, by the disruption of certain mRNAs. The authors conclude that the anti-cancer activities of pomegranate extract in HER2+ and triple negative cells are due in part to targeting microRNAs that play an important role in the proliferative/inflammatory phenotype of these cells.
Please see our article on how to optimize your breast cancer diet for information on what to eat during all stages of treatment and recovery.