Dr. Xu describes a mouse melanoma study in which histotripsy was used to mechanically destroy a primary tumor, and separate, untreated tumors that had metastasized to the lungs also shrank. The team measured a substantial increase in CD8+ T cells after treatment, suggesting the local tumor destruction triggered a systemic immune response that attacked cancer elsewhere in the body, something no drug had been involved in producing.
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The liver cancer focus traces to a specific personal motivation: PhD student Eli Vlaisavljevich, now a professor at Virginia Tech, asked to work on liver cancer because his mother died of it when he was a child.
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When the lab first proposed mechanically disrupting tumors, other researchers worried this could physically spread cancer cells rather than destroy them, a concern Xu says the field reacted strongly to.
338 words · auto-generated from the episode video
35:58That totally makes sense. Yeah. That's an incredible story. And, you know, one of the, one of the things I wanted to ask you about, you know, I was, as, as we were doing the deep dives into some of your papers, one thing that struck me was how histotripsy doesn't just, doesn't just accomplish its goal of using mechanical degradation to take out tumors. It also somehow supercharges the immune system. So you've got this paper here where, um, we have, um, I believe. Yeah. It's a mouse tumor model. Uh, and, uh, what we did is, uh, there's a primary
36:40tumor is a meninoma. So it's dark. You can see it. And also the mouse had an injection of the cells to form tumors in the lungs. So it's a pulmonary metastasis. What happened is that, uh, we had treated the tumor primary tumor, uh, and the found that there not only is a substantial increase in the immune response measured by the CDH plus T cells, but very, very, uh, you know, this kind of astounding effect is the, after primary tumor treatment, the lung metastasis, the tumors substantially shrunk.
37:22And it can only be explained by histotripsy actually stimulates the immune system and the immune system attack the tumor. We didn't even treat and make it shrinking. And this is, you know, basically what you're expecting new in therapy to do, but we are not even checking any drugs. Right. I mean, it's so striking. It's like an action at a distance. Um, so, so, so, so this is actually another surprising finding. Yeah. That's what I was going to ask. Like there's no way this was planned. No. So what happened is that when we, uh, you know, we're doing a clinical translation, uh, and, uh, eventually decided to attack the liver cancer.
38:07Okay. Uh, uh, and it was a long story and the liver cancer eventually determined to be, uh, this, uh, uh, clinical trial they were going to go down to.