Using CRISPR/Cas-9 To Treat Breast Cancer
1 in 8 women are expected to be diagnosed with breast cancer in their lifetime. Hearing the words “you have breast cancer” changes the lives of thousands of women every year. These women could be our loved ones, friends, neighbours and coworkers.
What Is Breast Cancer?
Breast cancer develops as a result of genetic mutations or damage to DNA. This often occurs because of what I’ll be focusing on today — inherited genes such as the BRCA genes.
BRCA1 (BReast CAncer gene 1) and BRCA2 (BReast CAncer gene 2) are genes that produce proteins that help repair damaged DNA. Everyone has two copies of each of these genes — one copy inherited from each parent. BRCA1 and BRCA2 are sometimes called tumour suppressor genes (because when mutated, cancer can develop.
People who inherit harmful variants in one of these genes have increased risks of various cancers — but most often, breast and ovarian cancer. A harmful variant in the BRCA1 or BRCA2 gene can be inherited from either parent. Any child of a parent who carries a mutation in one of these genes has a 50% chance of inheriting the mutation. Even if someone has inherited a harmful variant in BRCA1 or BRCA2 from one parent, they would still have inherited a normal copy of that gene from the other parent. But the normal copy can be lost or be changed in some cells of the body. Cells that don’t have any functioning BRCA1 or BRCA2 proteins can grow out of control and become cancer.
Brca1:
BRCA1 is located on chromosome 17 (one of the 23 pairs of chromosomes in humans) in the hg38 human genome and contains 22 exons (around 110kb of DNA) The Brca1 gene provides instructions for making a protein that acts as a tumour suppressor. This helps prevent cells from growing and dividing too rapidly or in an uncontrolled way.
Unfortunately, as previously mentioned, when mutated, this gene can lead to breast cancer.
Current Treatments:
- Surgery. An operation where doctors cut out cancer tissue.
- Chemotherapy. Using special medicines to shrink or kill the cancer cells. The drugs can be pills you take or medicines given in your veins, or sometimes both.
- Hormonal therapy. Blocks cancer cells from getting the hormones they need to grow.
- Biological therapy. Works with your body’s immune system to help it fight cancer cells or to control side effects from other cancer treatments.
- Radiation therapy. Using high-energy rays (similar to X-rays) to kill the cancer cells.
Treating Breast Cancer With CRISPR:
What Is CRISPR:
CRISPR is currently the most efficient and cost-effective gene-editing technology. CRISPR/Cas9 edits genes by cutting DNA and then allowing natural DNA repair processes to take over the rest.
To further understand how CRISPR works, check out my other article: https://siyanalalani.medium.com/crispr-101-manipulating-our-dna-56ae7fe3ea61
Breast Cancer Treatment:
Once the mutation is identified in the person’s gene, a gRNA would be designed for the target sequence (deep sequencing to detect known and new variants within your region of interest). From there, a homologous repair process (a naturally occurring nucleic acid repair system, that can be used to modify genomes in many organisms, including humans) would be used to repair the double-stranded break.
In short, with the resources needed (cas9, grna, DNA), they would be injected into the cells to treat the brca1 mutation.
After skin cancer, breast cancer is the most common type of cancer in women. Women all around the world develop this cancer every day. This treatment provides them access to a solution with fewer risks and negative effects on the body like surgeries and chemotherapy. On top of this, our current solutions still leave the risk of leaving the mutated gene to pass on to future generations.
CRISPR can stop this, CRISPR is going to change the future of breast cancer.
