Andrea 'Didi' Gardner

Didi is a graduate student researcher advised by Professor Amy Brock who came to the Department of Biomedical Engineering in 2018. Before graduate school, she obtained her B.S. in Bioengineering:Biotechnology from UCSD, and then worked with Weill Cornell Medicine and Cornell University to develop low-cost diagnostic kits for virally-driven cancers. Her current research focuses on the integration of quantitative single cell technologies with mathematical modeling to better understand the fundamental drivers of tumor heterogeneity. Her work is focused on two questions: (1) Do unique phenotypes within clonally-derived cell populations interact? Viewing the tumor as an ecosystem of cells, we ask -- Are subpopulations of cells interacting with each other and if so, as friend or foe? (2) What is the role of cell-cell fusion in tumor growth, maintenance, and cellular diversity? Cell-cell fusion is a fundamental biological process that was first noted in cancer in 1911, yet little progress has been made toward understanding its role in tumorigenesis and maintenance. By combining live cell imaging, RNAseq, and mathematical modeling we seek to reveal the story of the cancer fusion cell.

Fluorescently labeled phenotypic subpopulations of MDA-MB-231 cells were co-cultured to confluence and held there for multiple days to force competition before passaging. A mathematical model which describes interactions between the two subpopulations was fit with data obtained under normal growth conditions. We tested our model by simulating repeated passaging at high and low density conditions to assess predictions of ‘winners’ and ‘losers’ under different environmental conditions. In this figure we see that despite being seeded at 10% of the initial population, the GFP-labeled subpopulation is favored by high density conditions and has begun to outcompete the mCherry-labeled subpopulation as predicted by model simulations.