CRISPR, Cancer, and the Connection

By: Sophia Li

Cancer ranks second among the leading causes of death. Each year 602,350 people pass away from it (CDC). We've known this disease from all the way in 3,000 BCE in Egypt, yet we still haven’t found an efficient enough cure. Yes, we have radiation and chemotherapy as well as surgery, which work very well but have unwelcoming side effects. Losing hair, anemia, and the weakening of the immune system can all be side effects of the three procedures.

I’m sure you’ve all heard of cancer, but what exactly is it and how does it work?

Cancer is a “disease of the genome” in your cells in which they reproduce rapidly by mitosis. While it is normal and expected for cells to replicate for growth, repair, etc., cancerous cells’ reproduction is uncontrolled and happens quickly, forming tumors. If those tumors spread to other parts of your body, then they become cancerous, or malignant tumors. If they don’t however, they are benign tumors that are usually treated by surgery. Most of the time, cancer is caused because of your genes. The changes are usually found in proto-oncogenes, tumor suppressor genes, or DNA repair genes, all of which regulate mitosis. Normally, your body will edit out the damaged DNA before they form tumors, but “the body’s ability to do so goes down as we age,” (National Cancer Institute). There are 100+ types of cancer, thus a very serious disease, and we need to find an efficient solution fast.

CRISPR-Cas9 is a genome-editing technology found in bacteria when scientists noticed that bacteria could edit out viruses from their genes. When scientists found out, their interests shifted to isolating this bacteria and possibly using this in other organisms, such as humans or crops. CRISPR can be used - and has been used - in crops to resist drought and increase crop yield. Cas9 is an enzyme that guides sgRNA (self-guided) to edit, and most commonly knockout, a genome.

One solution to cancer is to cause the malignant cells to apoptose, or cause the cells to self-destruct. CRISPR creates a promising new hope for this. In one study published by Science, Daniel Rosenblum and his team created lipid nanoparticles, a new pharmaceutical drug delivery technology. Because of the sheer size of the cas9 protein, they had to create a larger drug capsule, which still remains a problem for CRISPR drug delivery in vivo (humans). He targeted the PLK1 gene, which is a kinase - a regulator- in cell division, and the lack of the gene leads to cell cycle death and cell surrender. One injection into patients caused tumor cell apoptosis, a 50% decrease in tumor growth, and a 50% increase in the chances of survival. Additionally, CRISPR edited around 70% of the PLK1 gene to produce these astonishing results.

With this new study, it makes way for a whole new path to genetic editing of various diseases, not just cancer. Many believe that CRISPR and others will make up the next generation of gene therapies. Still, editors like CRISPR and ZFNs should still proceed with caution, as this is a very new concept in the field of gene therapy. Yet CRISPR-Cas9 opens up a whole new world, and scientists need to take advantage of it. It may just be the perfect cure for cancer.