“For decades, cancer cells have been grown on flat, two dimensional substrates, such as Petri dishes,” says Denis Wirtz, the Theophilus H. Smoot Professor in the Department of Chemical and Biomolecular Engineering and director of the Johns Hopkins Engineering in Oncology Center. “This is mostly for convenience, so you can use powerful microscopes to visualize organelles and subcellular structures more readily.”
Also until now, most cancer drugs have been developed to halt cancer cell growth, Wirtz notes. The problem with that, he says, is that cancer cells in the body are not always in a growing state, but moving in three dimensions—as happens with metastasis, which accounts for the majority of cancer deaths.
So, hoping to make possible the development of anti-cancer drugs that target cell movement, Wirtz and his team at the Johns Hopkins Institute for NanoBioTechnology (INBT) are culturing cancer cells in a 3D growth medium. Hopkins researchers are identifying and quantifying hundreds of characteristics of these cultures at the single-cell level and have discovered some surprising things. For instance, instead of migrating randomly, cells in 3D environments move for long distances in one direction.
Using microscopes they modified to better view cells in 3D, Wirtz’s team concluded that today’s many common cancer drugs have little impact on cell movement. So, working with clinicians at the Johns Hopkins School of Medicine, INBT researchers will now search for drugs that do prevent movement. They are revisiting drugs that have been abandoned because they have no effect on stopping growth in 2D cell culture, and re-evaluating current chemotherapies in light of what is now known about cell movement in 3D.
Going forward, the Wirtz group is studying many different types of cancer cells, in the presence of a variety of drugs and in 3D growth matrices with different degrees of stiffness. Recent NIH funding also will allow Wirtz to begin to build a database of information about cancer cells that will be used by clinicians to improve treatment and patient outcomes.

