According to Baylor College of Medicine graduate student Rachel Atkinson, this was a serendipitous discovery. "I stumbled on this when I was a first-year graduate student. I was working with radiation and cancer stem cells, which are resistant to chemotherapy and radiation therapy. I had treated my cells with radiation and left them over the weekend. When I returned on Monday, I was disappointed because my cancer stem cells were dead and the normal cells were fine." She opened the incubator and her glasses fogged, giving her a clue that the temperature had gone up over the weekend. That was the clue that heat plus radiation appeared to be effective against the stubborn stem cells.
Ms. Atkinson also found that with the addition of hyperthermia the cancer cells could not repair the damage done to their DNA and most of them died. The heat also prevented the cells from increasing levels of most of the heat shock proteins, she said. The only heat shock protein that increased may explain why some of the stem cells progressed to a more differentiated state.