Valerie Weaver: Overcoming cancer's stiff resistance

E ach year in the United States alone, more than 200,000 cases of breast cancer are diagnosed. Most women fi nd their tumors on their own, by feeling a lump in their breast. Tumors can be detected in this way because they are stiffer than normal tissue, explains Valerie Weaver, Director of UCSF's Center for Bioengineering and Tissue Regeneration. This stiffness is both a consequence and a cause of cancer-ous processes in solid tumors. Weaver's work on cancer cells' interactions with the tumor microenvironment had its origins in her postdoctoral work with Mina Bissell at UC Berkeley, where she studied how integrin signaling affects the phenotypes of tumor cells (1, 2). Now, she is at the forefront of a burgeoning new fi eld, mechanotransduction, which seeks a better understanding of how cells sense and respond to physical forces (3–5). When discussing her career, she says it hasn't always been easy getting to that position , but, even with all the challenges she's faced, it's been worth it. When did you decide on a career in science? I come from a working-class background. Growing up, none of my friends were university bound. I think it was expected that I should learn how to type and get some kind of job with a nice pension, then get married and have a family. But I think I always knew I wanted something different for myself. I was a huge reader—I love books—and maybe that was why I decided to go to university. But I don't think I seriously considered a science career until well after that. After college, I was working at Chalk River Nuclear Labs, and my supervisor there really encouraged me to try to go farther. She could see my potential even though I couldn't. So I went to graduate school at the University of Ottawa and started a postdoc at the Canadian Research Council. My horizons just opened up—there were so many possibilities. But I still didn't really know if I could or should pursue a research career. Then I saw Mina Bissell give a presentation at the Canadian Federation of Biological Sciences meeting in Windsor. I somehow worked up the guts to run up to her at the end of the meeting and say, " Oh, I'd love to do a postdoc with you. " To my surprise, she said, " Well, contact me. " So off you went …