Cancer: disease born of abnormal cell mutation and DNA changes. A common theory in the medical field is that the larger the number of cells in a organism, the more likely it is to get cancer. More cells equals more mutations equals more cancer. Makes sense right? Logically yes, but reality says otherwise. Peto's paradox explains this exact phenomenon. This paradox states that body size and cancer risk don't actually correlate as much as we think. Animals with 1,000 times more cells than humans don't show an increased cancer risk, meaning that natural mechanisms may suppress cancer 1,000 times more effectively than those in human cells. The biggest example for this paradox (pun intended) is the bowhead whale. Swimming through arctic waters at a whopping 80,000 kg, this animal can live up to 200 years cancer free. But how?
Let's learn how cancer truly spreads. Every time your cells divide, there is a risk that the DNA within them doesn't get replicated accurately. There may be breaks in the strands of DNA. Proteins in your body rush to fix it, mending and joining as quickly as possible. Sure it may work, but its a sloppy fix where everyone hopes for the best. Unfortunately, this can lead to cell mutation which, over time, can lead to cancer. This is where bowhead whales come in. Instead of messy joints between broken DNA, the whales have perfected accurate DNA reconstruction. The protein CIRBP plays a huge role in this beautifully orchestrated cancer protection.
So what exactly is CIRBP? CIRBP is a repair protein which detects and fixes broken DNA with almost perfect precision. This leads to cleaner and less damaged cells and DNA. Its full form is Cold-Inducible RNA-Binding Protein (admittedly sounds confusing but sit tight). Cold-inducible refers to the quality of this protein to get activated in the cold, just like the chilly arctic where these whales live. Their bodies adapted this mechanism to its surroundings, making it even more effective. A fun fact is that humans too have this repair protein, but the version in whales differs by just 5 amino acids. It’s not just the structure though, its the sheer quantity: whale cells actually produce 100 times more CIRBP than human ones.
Scientists at the University of Rochester, namely Vera Gorbunova and Andrei Seluanov researched on CIRBP in whales. Human cells were engineered to produce bowhead whale CIRBP so they could observe its repair capabilities. Surprisingly, DNA repair improved as a result with a highlight in increased protein expression. What that means is that the number of CIRBP produced by cells increased by a huge amount, meaning greater hands on deck. These findings were a major breakthrough, helping us understand how even animals which live miles away can help us learn more about ourselves. From the tiniest of cells to the deadliest of cancers, whales have opened up newer doors to potential cancer prevention and cure for humans.
