Jing Yu





The (short) cancer story

When people learn I’m a cancer researcher, I typically find myself answering the same set of questions — What causes cancer? How can I prevent cancer? What is cancer? Why haven’t we found the cure yet? There’s an unhealthy prevalence of misconceptions and misinformation about what cancer actually is. Without at least a rudimentary understanding of the disease, it’s really difficult to answer those previously mentioned questions. The first step to conquering a disease has always been to understand how it works. Now, full disclosure — explaining cancer pathology always comes with the risk of being didactic, dry and chronically misunderstood, but Cancer demands, with it’s devastating prevalence, our attention. It’s not a disease in the classic sense of the word, a cancer patient is not being assailed by some foreign invader as in AIDs or pneumonia, cancer is a rebellion of our own cells.

So how is it that just a handful of corrupted cells can overwhelm a system of over a 100 trillion cells that make up the human body? Every cancer story starts with in the DNA, the instructions that predetermine a cells destiny, everything from its birth, function and death. The complex machinery of our body is only possible because our cells comply with the commands of its DNA.

Let’s take a closer look at two examples within the human body, the melanocyte (mela·no·cyte) and the hepatocyte (hep·a·to·cyte), each with a very different function. The melanocyte lives in the skin and is instructed to produce melanin as a defensive reaction to UV exposure — manifesting as a freckle or tan on your skin. The hepatocyte, which lives in the liver, purifies toxins, produces vital proteins and stores energy from your meals. This hepatocyte is also programmed to die at five months whereafter a fresh hepatocyte will take its place. Your DNA is instructing these cells to complete their functions until their inevitable self-destruction. However, if these directives (along with a few other safe-guards) break down, cancer is the result.

After one too many sunny days on the beach, our melanocyte, which was once charged with protecting the skin from UV radiation, may find whole sections of its DNA fried beyond repair. Without these sections, this melanocyte no longer has a complete set of rules to follow. Most importantly apoptosis or programmed cell death, is no longer mandated. Cells that do not go through apoptosis are by definition cancerous cells. Cancer cells are then bifurcated into benign and malignant cancers. At the cellular level, this only means that benign cells have forgotten to die but also do not multiply. Malignant cancer, on the other hand, occurs when our cells not only refuse to die but also begin to multiply. In the case of the malignant melanocyte, our once good melanocyte goes on reading the readable sections of DNA that tells it to divide and grow but without its death directive, rapidly outgrows it’s little freehold and begins to spread to neighboring real estate — this is known as metastasis.

Ultimately, this is what kills us. Nothing vile and nothing even foreign, simply some of our own cells, which have forgotten to die and continue to expand. As they grow inhibited, these cells infringe on the territory and resources of other healthy, functioning cells. Essentially, death by cancer is a result of useful organs being replaced with cancer cells. Cells who’s only mandates are to grow and consume resources, good habits for cell survival but bad for human survival.

For example, in a heathy liver, a hard working hepatocyte compliantly dies around five months where after a fresh hepatocyte will take its place. However, in our case of malignant melanoma, the space recently vacated by the old hepatocyte becomes a home for the malignant melanocyte instead of a fresh, high-useful liver cell. Healthy cells typically do not grow where there is no space to grow, so a cancerous melanoma will find no competition with new hepatocytes. In another 5 months the next generation of compliant hepatocytes will be replaced by metastatic melanocytes. On the outside, the human begins to exhibit fatigue and loss of appetite, early signs of liver failure.

Now, armed with a simple understanding what happens in cancer, we can finally began to apprehend the big question on everyones mind — where is the hell is the cure?