Recent research on mice found stem – like cells in breast tissue that seem to increase risk of cancer. Scientist found specific gene – regulating molecules called micro RNAs that have a way to repress this stem-like cells. It is discovered that if certain forms of breast cancer origin from this stem- like cells and because of this it’s very important to find way to selectively attack them in order to prevent or reduce breast tumor.

Previous researches showed that micro RNA called let-7 is related to tumor suppression. This new study however discovered that it can be delivered to breast tissue cells where it can separate stem-like cell that initiate tumor form the other cells that are fully developed . Scientists also found that by expressing let-7 in the sample they were able to attack and eliminate just the cells that represent potential risk of breast tumor.

Researchers found that a key ingredient for this study was the use of a mouse breast-derived model cell system called COMMA-1D which is discovered to separates cells from one another and it also includes stem-like progenitors in various stages of growing. It was found during the study that administration of cyclophosphamide in mouse cells had the effect of enriching for these cells. This is the first thing that gives new idea to find how can these therapies have effect in cell culture in real tumors and than to look for the effect that it has on metastasis and probably find a new therapy.