The opener for what is, at the moment, the second chapter of The Man Who Signed the City. The subject, biophysicist and cancer researcher Denis Wirts.
Galen of Pergamos was a physician with a practice in second-century Rome. Among his clientele was the Roman Emperor Marcus Aurelius. Galen was also a prolific scribbler, so we know a lot about his ideas on disease, including his theory of cancer. Cancer, he wrote, was caused by “black bile” that flowed through the body. Anywhere it became trapped, it formed a malignant tumor.
He was wrong about black bile, though it is one hell of a good metaphor. But he was strikingly close to the mark with his flow theory. There are cancers, such as glioblastomas in the brain, in which the primary tumor can be deadly. But for most people, the original tumor does not pose the mortal threat. In more than 90 percent of cancers, what kills is metastasis. Cancer cells have a terrifying ability to move through the body and form new tumors in the bones, in the lymph nodes, in the lungs, in the liver and other internal organs. If a physician finds your tumor before the cancer has spread, you may survive. If the tumor has metastasized, cancer will kill you. Medicine has few weapons to counter the flow of black bile.
What if that is, in part, because a large portion of cancer cell biology and cancer drug testing has been reliant on a ubiquitous piece of lab equipment? The wrong piece of lab equipment? German bacteriologist Julius Richard Petri invented the Petri dish in 1887. Unless it was invented two years before that by a Slovene, Emanuel Klein, or by a pair of Romanian microbiologists, André Cornil and Victor Babes. Unless it was invented a year before that—we are back to 1884 now—by English researcher Percy Faraday Frankland. Whatever its provenance, the two-piece flat cylindrical glassware (now frequently polystyreneware) has been used by scientists for decades to culture and study cells of all kinds, including cancer cells.
Denis Wirtz is a professor of chemical and biomolecular engineering at Johns Hopkins University. He has dedicated the past few years to developing methods of studying cancer cells in three-dimensional environments. In a Petri dish, cells are cultured on a substrate so thin as to be effectively two-dimensional. Wirtz believes that this 2-D microworld-in-a-dish so distorts the cells and their behavior as to cast doubt on a significant part of critical cancer biology. He and his research team have been growing and observing cancer cells in 3-D matrices that are much more like human tissue. The difference has been so dramatic that when Wirtz talks about it, he becomes an evangelist for cell biology in three dimensions. To figure out metastasis, he says, scientists must work in 3-D. And it would be a good idea to take hundreds of drugs, deemed failures after testing them on cells in a dish, and test them again in 3-D matrices. Wirtz thinks pharmaceutical companies may have missed medicines that will work because of their reliance on Herr Petri's invention.