Defective Stem Cells The Cause Of Breast Cancer?

Returning breast cancer could be caused by newly discovered rare stem cells transformed into a "tumour factory" by genetic errors, according to a report by Australian scientists in 'Nature'.

The research team from the Walter and Eliza Hall Institute of Medical Research in Parkville, Australia,believe that as well as driving all breast development, the cells could have a key role in cancer.

The Researchers transplanted the cells into mice tissue and were able to grow a fully-functioning breast, they found the key stem cells were more numerous in pre-cancerous tissue.

The research provides hope in two ways, the development of new cancer therapies, as well as new techniques for breast reconstruction.

Scientists from the research team isolated the stem cells from a structure in female mice called the breast pad. They transplanted one of the cells into the mammary fat pad of a living female mouse from which all breast tissue had been removed.

The cell divided and eventually gave rise to all the normal types of cell found in the mouse breast to such an extent that the gland produced milk in the normal fashion.

In human terms though there is no proof the stem cells exist in humans, the team is almost certain they do because of the expansion of breasts during pregnancy and puberty.

The team also found that chemotherapy designed to target tumours may not be effective at wiping out any of the defective stem cells in the breast as they divide at a different rate.

The Australian-led team reported that chemotherapy works by targeting cells that are dividing rapidly, which is typical behaviour of cancer cells, but a defective stem-like cell may be more resistant to chemotherapy because it divides more slowly.

The results would eliminate the bulk of cancer cells, the tumour producer itself a breast cancer stem cell could survive months or years later."

The team believe that a 'wonder-drug' development should look at a drug that can switch off the faulty stem cells.

To develop this form of cure though, the exact make-up of genes in normal and rogue cells needs to be determined.

The charity BreastCancer Care say the research was interesting, but that it was at a very early stage as it has only been carried out in mice.

Further research would be required to determine if the same stem cells exist in humans, as well as a greater understanding of other factors that influence a person's likelyhood of developing breast cancer.