Cancer therapies can dramatically shrink tumors, but a small number of cells often survive treatment and later drive the disease's return. To better understand and eliminate these elusive "persister" cells, UCSF School of Pharmacy researchers in the Department of Pharmaceutical Chemistry’s Altschuler-Wu Lab have developed a robotic platform capable of tracking and testing thousands of miniature tumors simultaneously, revealing shared weaknesses that could be exploited by future cancer therapies.

The study, published in Science Advances on June 12, was led by Xiaoxiao "Vany" Sun, PhD, assistant researcher in the UCSF Department of Pharmaceutical Chemistry, with co-senior authors Steve Altschuler, PhD, and Lani Wu, PhD, professors of pharmaceutical chemistry and co-directors of the Altschuler Wu Lab. Additional UCSF Department of Pharmaceutical Chemistry authors included Savitha Gayathri, MSc; Karl Kumbier, PhD; Heinz Hammerlindl, PhD; and Erin Ahern.

The team designed the automated system to take on a longstanding challenge in cancer research: persister cells are exceedingly rare, difficult to isolate, and can lose their defining characteristics before scientists have a chance to study them. By enabling researchers to systematically identify, monitor, and treat these surviving cells at unprecedented scale, the platform offers a new window into why cancers recur after initially successful treatment.

"We expected each tumor to behave as its own special case," said Altschuler. "Instead, we found patterns that held up across many different samples, suggesting there may be underlying rules that can help predict which therapies are most likely to work."