“How do we interact with the world around us?” That’s a broad question, and it can be hard even to begin answering it. To me, the answer boils down to one key point: to interact with the world, to react to our surroundings, we need to get information from our surroundings, understand what it means, and formulate a reply. We do that with our five senses: sight, hearing, touch, taste, and smell. So, if someone across the street were to wave, we’d have to see them do so, understand that it’s a greeting, and wave back. Just like us, our cells need a way to interact with their surroundings, and again, like us, they also have senses. They don’t have the typical senses we have, but they can gather information from their surroundings, interpret it, and react to it. For example, they can understand chemicals, just like our senses of taste and smell. They can also interpret physical sensations, a lot like our sense of touch. Our cells use this information to stay healthy, often using their senses to collaborate with other cells. In cancer, they can use their senses to grow more aggressively. But — we might be able to take advantage of that.

As a tumour grows, enormous changes occur in the organ it grows in — and the body as a whole (but that’s rather complicated, so we’ll save that for another time). They damage other cells; they can damage or squish blood vessels, and they can starve out healthy cells. Something that tumours can cause that is often overlooked is “fibrosis”. As tumours grow, cancer cells can deposit fibre-like materials. By packing all the small gaps between cells with these fibres, the tissue begins to stiffen. This newfound tissue stiffness, although it sounds relatively harmless, can become problematic.

Because cells can interpret physical signals in their surroundings, much like our sense of touch, cancer cells can actually sense differences in stiffness. As cancer cells detect toughness in their surroundings, they can react, causing them to become more aggressive.

At the moment, fighting cancer by tackling the tumour tissue isn’t a real option. The field is too new, and it still has a lot of growing to do. But, with that said, some of the research that’s being done in this field is incredibly exciting. A study published this year looked into the possibilities for cancer treatment by targeting mechanical senses, and the findings are fascinating. This study, led by Jasmin Kaivola, comes from a Finnish research group studying vocal fold cancer. Vocal fold cancer is one of the cancers where fibrosis is incredibly common. This can be particularly difficult for patients because, apart from the problems we’ve already mentioned, vocal folds are a particularly mobile tissue. So as they seize up with fibrosis, it can permanently impact someone’s ability to speak.

This study started with a question: “If the transition from mobile and vibrating vocal folds to fibrous and immobile vocal folds leads to a worse outcome, what happens if we go in the opposite direction?” To answer that question, the researchers took tough, fibrous vocal fold cancer and they… vibrated it. Specifically, they used different apparatuses to vibrate the cancer at a frequency that matches the frequency of normal speech. Their results were incredible.

Essentially, by mimicking the movement of healthy vocal folds, they undid many of the aggressive characteristics that tougher tissue leads to in cancer. This is largely because when the tissue is softer and more mobile, the cancer cells sense that information and respond differently than when the tissue is tough. These scientists are using the cells’ so-called senses, senses that can even promote aggression, against cancer. Although their work is early and there’s a lot of follow-up needed, the idea that simple vibrations could revert a cancer’s aggression is amazing.

Cancer is much more than just a growth of cells. It can deeply impact the organ it’s in and the body as a whole. Despite that, it’s easy to overlook some of the quieter impacts when a big tumour is sitting there. One of those often-overlooked impacts is fibrosis, the toughening of tissue by cancer. And, although it may seem relatively minor, cancer cells can sense that tough tissue and become more aggressive in response to it. The idea of tackling cancer indirectly, by treating the tissue itself, is a highly active field of cancer research. One study in particular caught my attention this year. By mimicking the vibrations and movement that a healthy vocal fold would experience, they reversed the aggressive characteristics of vocal fold cancer. That finding is astounding, and it opens a door to further research into treating cancer by treating the tissue. With that said, it’s also important to acknowledge that this was not done in people. Although they used both human and mouse vocal fold cancer for this study, the environment is completely different from that in people. That shouldn’t undermine their findings; it just means there’s a lot more research needed to see how this might affect real patients. So even though there’s a lot to do, the idea that we can slow cancer with vibrations is thrilling.

I hope you learned a little something this week, but from now on I’m going to sing even louder in the shower.

See you next week!

If you missed last week’s letter, you can read “Tiny Giants” to learn a little more about giant cancer cells and how they work.