The concept of curing cancer has become this idiom we use to either highlight the intelligence of someone or to emphasize how important or unimportant something is. For example, think of a mother saying about her daughter “She’s so smart she’s going to cure cancer one day” or when a student is frustrated in a chemistry lab and the professor says, “calm down, you’re not curing cancer here”. Culturally, we tend to view the concept of curing cancer as this ultimate yet out of grasp goal. Cancer is truly the epidemic of the modern age taking the #2 slot in most common cause of death on the CDC’s website. Finding a cure would indicate that modern medicine has truly evolved allowing humanity to reach new heights scientifically. Yet, how does a scientist tackle this goal of progressing modern medicine, especially in a field where there are thousands of scientists working towards the same goal? To answer this, I would like to quote Mr. Big Weld from my favorite childhood movie, Robots, “see a need, fill a need!”
History of Chemotherapies
Cancer therapies have been in development since the 20th century with chemotherapy being introduced in the 1930’s. It was discovered that soldiers exposed to mustard gas from both World Wars had lower amounts of leukocytes in their blood, leading to the development of nitrogen mustard as the first form of chemotherapy against lymphomas. Chemotherapy was a great alternative to older styles of surgery which were more aggressive and involved the removal of excess tissue to prevent the resurgence of tumors. The need to avoid the elimination of healthy tissues, and even an entire surgery, was met with the development of chemotherapy. That’s not to say of course that there aren’t issues with chemotherapy itself.
The Need: Specificity
There are so many unfortunate side effects caused by some cancer treatments because of lack of specificity. It is difficult to design a drug that specifically targets the tumor and avoids other healthy cells in our bodies. If you know someone who has had cancer and was treated via chemotherapy, most likely, you’ll remember that person lost their hair. You were also probably told this is because their therapy targets cells that rapidly divide, and hair follicle cells are within that realm. They take the drug, and then their hair falls out because the medication is killing off those cells. Research scientists are trying to develop drugs that can selectively target cancer cells without causing consequences on other types of cells. The particular method I will talk about today is called Photoactivated Cancer Therapy, or PACT, for short.
What is PACT?
The main concept of PACT is that you take a pill that contains a compound that is harmless. That compound is then distributed through the bloodstream to all cells. However, when light is shone onto the compound, it becomes “activated” and becomes cytotoxic. The general thinking is that to treat a patient who takes this drug, light would be shone onto the area with the tumor, activating the drug and causing only the affected cells to die. This new unique form of treatment addresses the lack of specificity in most cancer therapies.
What molecules are good candidates for PACT?
Most compounds that are sensitive to light reactions are inorganic in nature, meaning they contain metals. There is already a metal-based compound that is commonly used in cancer therapy, called cisplatin. Cisplatin is able to target rapidly dividing cells, but then is unable to distinguish what’s a healthy rapidly dividing cell, and a tumor cell. I learned all about this molecule in my inorganic class at the University of Richmond. Metal compounds are being developed that can react with light, change shape, and turn into a more toxic drug. There is still a lot of research to do that focuses on the tunability and optimization of these metal compounds and I’m excited to see what the future will bring.
PACT provides insight into not only how modern medicinal techniques can be improved, but also how the daily lives of those affected with cancer can too. Hopefully soon cancer patients won’t have to lose their hair, and can even receive more effective treatment with this new method.