Episode Transcript
Interviewer: A social lifestyle with plenty of mental activity and exercise slows down cancer according to research in mice. We'll talk about that next on The Scope.
Announcer: Examining the latest research and telling you about the latest breakthroughs, The Science and Research Show is on The Scope.
Interviewer: I'm talking with Dr. Melinda Angus-Hill, an investigator at the Huntsman Cancer Institute at the University of Utah. Dr. Angus-Hill, I really love this story. Your research is showing how a change in lifestyle can really impact the trajectory of cancer.
Dr. Angus-Hill: We have a mouse model that is meant to replicate colon cancer in humans. We've developed genetic mutations that profoundly influence the numbers of colon tumors that these animals get and we found that with enriched lifestyle, which includes improved social interactions with lots of other mice, they have huts and crawl balls and lots of things that they can do, lots of activities, they have wheels that they can run on, and we found that these improved social interactions and these things that they can do increase their lifespan of both males and females significantly.
Interviewer: By how much?
Dr. Angus-Hill: So, these mice, normally, begin to get sick with colon tumors at around three to four months old and they'll live two to three months longer than that with the environmental enrichment.
Interviewer: Which is pretty significant for a mouse?
Dr. Angus-Hill: Yes, very significant.
Interviewer: Like you mentioned, they're subject to a lot of changes compared to regular lab mice. I mean, you said they're around a lot of other mice, they're getting exercise, they're, you know, maybe just faced with a more interesting environment than they would usually have. Do you know if . . . it is a combination of those things that are impacting the mice or can you parse it out into one of those changes?
Dr. Angus-Hill: Well, I think it is actually all the entire environment that does this. There have been a lot of studies that have looked at exercise and the effects on tumor genesis and, basically, they give a single mouse a wheel and mice can run on the wheel as much as they like, and will often just spend the whole day running. They can run up to six kilometers a day under those conditions and that can actually be stressful on mice, but it will still have an effect on whether the size of the tumors decrease and whether the animals actually feel better. But it seems that this environmental enrichment is more a well-rounded approach where the animals, they can run if they like to, but there are many other things that they can do and that seems to improve in a different way than just running on a wheel.
Interviewer: So a lot of your work here which is really the advantage of working in mice or a model organism is trying to understand, you know, biologically, what's going on here. How is this environmental enrichment changing the biology of these mice? I mean, first of all, what's happening with the cancer? Is it not starting in the first place? Is it just progressing slower than cancer normally would? What are you seeing at that level?
Dr. Angus-Hill: Sure. It seems that we don't have a decrease in the numbers of tumors that actually initiate, which suggest that the genetic mutations that occur, you can't really stop them from occurring with environmental enrichment. However, it seems that we can actually make the tumors better. So, if a tumor can be better . . .
Interviewer: Yeah.
Dr. Angus-Hill: But the idea is that with environmental enrichment, there is less inflammation which results in what we think is, actually, a cause of a healing phenotype that occurs when the mice are environmentally enriched. So, basically, the tumors become more benign and they are less offensive. So, in the context of cancer, these tumors would be less likely to invade and metastasize, and become a serious problem.
Interviewer: Right. And you were talking about how it seems to trigger a wound healing process, which seems a little counterintuitive to me. I mean, what does wound healing have to do with cancer?
Dr. Angus-Hill: We were actually able to show that the animals, the male animals in particular, had an improved wounding process that happened in their colons. Basically, their tumors healed themselves with this environmental enrichment.
Interviewer: Like wound healing in our skin or . . .
Dr. Angus Hill: It's actually been most well-characterized in the skin and it has to go through multiple steps in order to complete the healing process, and so it has to get worse before it can get better. So there are several steps, including recruitment of inflammatory cells, increased angiogenesis which is making more blood vessels, and then, basically, the wound can resolve by re-epithelializing the cells and then, ultimately, a scar will be formed, and all of this will result in decreased inflammation.
So we saw decreased inflammation with environmental enrichment. This suggested to us that the colons and the colon tumor, this barrier that is normally essential for maintaining the . . . keeping the bacteria out, but also maintaining the normal cell structures in the colon were actually being helped with environmental enrichment.
Interviewer: I mean, this is really a different way of thinking about things. I mean, are you excited about sort of the possibilities here or . . .
Dr. Angus-Hill: Yeah. I think it's kind of a new idea that really, it's not super appealing to pharmaceutical industries, but it's something that everybody can take to heart and know that it's possible that reducing stress can actually improve your gut, you know, even just inflammation in general, and I think more studies are definitely needed to determine whether this translates to people, but you know, what harm is there in reducing stress? There are none. There are no harms to reducing your stress.
Announcer: Interesting, informative, and all in the name of better health. This is The Scope Health Sciences Radio.