Just days after we reported a development wherein researchers grew fully functional forelimb of a rat in lab, a team of researchers have grown mini-breast in petri dishes that they say will aid in cancer research.
Pegged as a technological breakthrough, the mini-breast is a result of work of a research group, led by Dr. Christina Scheel of The Helmholtz Zentrum München, the German Research Center for Environmental Health, developed an assay whereby cultured human breast epithelial cells rebuild the three-dimensional tissue architecture of the mammary gland.
Researchers used a transparent gel in which cells divide and spread, similar to the developing mammary gland during puberty. Specifically, cells divide and generate hollow ducts that form a network of branches and terminate in grape-like structures.
It is known that throughout the reproductive lifespan of a woman, the mammary gland is constantly remodeled 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, i.e. stem cells.
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Image: Haruko Miura Copyright: Helmholtz Zentrum Munich
A technological break-through
The scientists used their newly developed organoid assay to observe the behaviour of cells with regenerative capacity is determined by the physical properties of their environment.
Jelena Linnemann, first author of the study, explained that they were able to demonstrate 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.
Results of the research suggest that invasive growth in response to physical rigidity represents a normal process during mammary gland development that is exploited during tumor progression.
Co-author Lisa Meixner adds that “with our assay, we can elucidate how such processes are controlled at the molecular level, which provides the basis for developing therapeutic strategies to inhibit them in breast cancer.”
Another reason the mini-mammary glands represent a particularly valuable tool is, because the cells that build these structure are directly isolated from patient tissue. In this case, healthy tissue from women undergoing aesthetic breast reduction is used. Co-author Haruko Miura explains: “After the operation, this tissue is normally discarded. For us, it is an experimental treasure chest that enables us to tease out individual difference in the behavior of stem and other cells in the human mammary gland.”
Experimental models that are based on patient-derived tissue constitute a corner stone of basic and applied research. “This technological break-through 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”, says Christina Scheel, head of the study.
