UC Santa Barbara

Branching morphogenesis is a fundamental process that occurs during the development of the mammary gland, and several signaling pathways that regulate mammary branching are disrupted during the development and progression of breast cancer. Much of our current understanding of morphogenesis comes from the effects of chemical morphogens, though recent work has revealed that the mechanics of the extracellular matrix (ECM) can regulate morphogenetic events. Conventionally, tissue development has been studied with ex vivo systems where mechanical properties of the extracellular environment are either poorly controlled in space and time, lack tunability, or do not mimic the native extracellular matrix mechanics. For these reasons, it remains unknown how matrix stress relaxation rate, a time-dependent mechanical property shown to influence several cellular functions and processes, regulates tissue branching in mammary development. My objective here is to determine the effect of ECM viscoelasticity on mammary branching using 3D collagen-rich matrices with tunable stress relaxation and spheroids of human mammary epithelial cells.