More people are diagnosed with skin cancer in western countries than any other cancer combined. In fact, Melanoma, a highly dangerous type of skin cancer, is estimated to claim one life every hour. So, what if you could lower your risk of skin cancer by changing the color of your skin? Does skin cancer depend on skin color?
Ok, this is a big subject, so let’s start with the science. Everyone has something in their skin called Melanin, a biological pigment that gives us the color of our skin, hair, and eyes. Melanocytes are the cells in our epidermis that make this pigment and everyone has the same number of them, but everyone’s melanocytes make different amounts of melanin, and different kinds.
Melanin plays a few very important roles besides giving your skin its color. Your skin is being exposed to harmful ultraviolet rays of the sun when you are outside. The DNA of your skin cells can get damaged when it’s prolonged exposure to UV radiations and can start to malfunction disrupting the life cycle of your skin cells. Potentially causing uncontrolled replication and leading to cancerous growths.
Your body has a couple of defense mechanisms one of which is your Melanocytes. The little melanin-producing factories called Melanosomes are inside your melanocytes. If the mitochondria are the powerhouse of the cell, the melanosome is the powerhouse of the melanocyte. Eumelanin-a darker pigment and Pheomelanin-a light-colored pigment are two kinds of melanin produced by these melanosomes.
Eumelanin blocks UV photons from damaging the skin, so those without a lot of it (people with lighter skin) are at higher risk of sun damage. So, when your skin is exposed to more sun, your melanocytes are ‘turned on’ to produce more of this UV-blocking melanin to protect your cells. How much melanin and which kind your skin makes is controlled by your genes. That’s why when exposed to sunlight some people’s skin tone deepens or starts making more melanin. Others can’t produce more than a certain amount of melanin, and so find their skin exposed to more damage resulting in sunburn.
So, more melanin equals darker skin tone and equals more protection from the sun’s harmful rays. The big takeaway from all this detail is that those with more melanin, particularly eumelanin, are at decreased risk for skin cancer. And now, for those who don’t have it naturally, researchers have explored how to induce artificially the level of protection.
It turns out that the melanosomes that produce the two different types of melanin have different pH’s, and remember the melanosome is that little pigment making machine inside your melanocytes. The dark, highly protective pigment-Eumelanin, is produced by melanosomes that are less acidic than the melanosomes that produce pheomelanin.
So, researchers have posited and now shown that they can actually change the relative amounts of which kind of melanin your melanosomes produce. Inhibiting a certain enzyme, called sAC, can make melanosome pH less acidic and allows those cells to produce more eumelanin–meaning darker pigmentation and increased protection from skin cancer.
We’re still not exactly sure why pH influences what kind of melanin your melanosomes produce, and this is an area that researchers are hoping to explore further. It’s important to note that this is different from regulating melanin production by changing the way your genes are expressed, it’s not genetic editing. A pharmaceutical drug that induces pigment production depends on the result of this new research potentially for use by populations vulnerable to skin cancer, or those with pigmentation conditions that they’d like to treat.
This is still in the very early stages though, being tested in mice and human skin cells in Petri dishes. It’s a long way away from practical applications in humans. The color of someone’s skin has been something that defines and often divides humans for millennia. So, if it becomes possible for us to change that color in a very fundamental way for medical purposes, what does that mean for our conception of things like race? Would its use be ethical? What do you think about this research?