London, Jun 13 (IANS): Researchers have developed a method whereby cultured human breast epithelial cells rebuild the three-dimensional tissue architecture of the mammary gland.

The findings provide insights into the behaviour of breast cancer cells and the ways to stop them.

"This technological breakthrough provides the basis for many research projects, both those aimed to understand how breast cancer cells acquire aggressive traits, as well as to elucidate how adult stem cells function in normal regeneration", said study leader Christina Scheel from the German Research Centre for Environmental Health.

The researchers used a transparent gel in which cells divide and spread, similar to the developing mammary gland during puberty.

Throughout the reproductive lifespan of a woman, the mammary gland is constantly remodelled and renewed in order to guarantee milk production even after multiple pregnancies.

Although their exact identity remains elusive, this high cellular turnover requires the presence of cells with regenerative capacity, that is, stem cells.

Breast cancer cells can adopt properties of stem cells to acquire aggressive traits.

Using their newly-developed organoid assay, the researchers observed that the behaviour of cells with regenerative capacity is determined by the physical properties of their environment.

"We were able to demonstrate that increasing rigidity of the gel led to increased spreading of the cells, or, said differently, invasive growth. Similar behaviour was already observed in breast cancer cells," said first author Jelena Linnemann.

"Our results suggest that invasive growth in response to physical rigidity represents a normal process during mammary gland development that is exploited during tumour progression," Linnemann explained.