Eliminating Malaria Worldwide and Genetic Breast Cancer in the Next Five Years
Are You Kidding?
Consider this: One of eight women will get breast cancer in their lifetime. At least 15 to 20 percent of these women will have genetic or heredofamilial breast cancer.
Genetic breast cancer is when you have a blood test that confirms the presence of an abnormal gene, such as BRCA 1 or BRCA 2. Meanwhile, the chances of suffering from heredofamilial breast cancer is higher than the normal lifetime risk of 12.4 percent. This increased risk is related to mothers, sisters, aunts and other female relatives who have had breast cancer.
A person plugs their own family history into a chart and gets their risk profile. However, when a blood test is done to find the gene that produces this risk, the results are negative. In other words, heredofamilial breast cancer is the same as genetic breast cancer with genes that just have not yet been discovered.
Enter our story about CRISPR/Cas9 and gene drives. The CRISPR/Cas9 system is basically gene editing. In the same way you can cut and paste words on your computer, the CRISPR/Cas9 system allows one to similarly edit genes and replace them. The CRISPR/Cas9 system exists ubiquitously in nature and in most species, including humans. It was discovered in naturally occurring bacteria in the ocean. We all contain bacteria; therefore, we all contain the CRISPR/Cas9 system naturally. This technique is not only ubiquitous, it is inexpensive and, in all likelihood, could be reproduced and created by a sophisticated biology student in high school or college. This is both amazing and frightening. But it is an unstoppable technology.
Simply put: you can edit any animal’s genome with the CRISPR/Cas9 system.
You could potentially create a woolly mammoth out of an elephant if you have the woolly mammoth’s DNA (and we do from fossilized material).
In our lifetime, there could be woolly mammoth zoos. It cost $100 million for Craig Venter to sequence the human genome in 2000, and today you can have your entire genome sequenced for between $100-$500.
Fast forward to malaria, which kills 1,000 people per day, many of them children. What would happen if you made the anopheles mosquitoes that transmit malaria that contain an antimalaria gene? We can do that right now. Thanks to CRISPR, engineering a malaria-resistant mosquito is possible. But how do you get your mosquito with that malaria-resistant trait to spread? This is where it gets interesting. Kevin Esvelt, a biologist at Harvard, wondered what would happen if CRISPR inserted not only your new gene, but also the machinery that does the cutting and pasting with it.
In other words, what if CRISPR also copied and pasted itself? You would have a perpetual motion machine for gene editing in offspring after offspring after offspring. That is exactly what happens when you release these malaria-resistant anopheles mosquitos into African villages. This CRISPR gene drive that reproduces itself not only guarantees that a trait will get passed on from mosquito to mosquito, but if it is used in the germline cells, it will automatically copy and paste your new gene into both chromosomes of every single individual.
In other words, all of the babies of the malaria-resistant mosquito and the malaria-prone mosquito will be malaria resistant. It is like a global search-and-replace. At the same time, you can link the malaria-resistance gene to the color of the mosquito’s eyes. This allows you to identify what type of mosquitoes are circulating in your village and learn when the malaria-prone ones are completely gone by simply looking at their eye color. We will eliminate all malaria-carrying mosquitoes in the next two to five years.
This leads us back to breast cancer. We know that women who have genetic breast cancer have a positive blood test that allows us to currently identify the specific gene mutation (BRCA 1, BRCA 2). Heredofamilial breast cancer is genetic breast cancer where the gene has not yet been identified. Once we identify all of the genes (and we will), we will be able to take our CRISPR protein that acts like scissors and cut the DNA where the mutation has been identified. There is an RNA molecule that directs this DNA scissors to any point in the genome.
The result is basically a computer program for genes. You can take a gene out, put a gene in or even just edit a single letter within a gene. And you can do it in any species.
The title “Are You Kidding?” can be answered with the following statement: “No, I am not kidding.” We will eliminate malaria in the next five years and the 1,000 deaths a day that come with it. We will eliminate genetic and heredofamilial breast cancers whose genome is identified and rectified by the CRISPR/Cas9 system and the gene drives that allow it to proliferate when needed.
If this article gives you pause, it should. (I know what you must be thinking … bioterrorism). But scientists have acted responsibly and carefully, and the risk that some terrorists might acquire technology and use it improperly is remote for a number of reasons.
Nevertheless, prepare to see woolly mammoth farms.
Kahn, J. (2016, February 16). Jennifer Kahn: Gene editing can now change an entire species – forever. Retrived from https://www.ted.com/talks/jennifer_kahn_gene_editing_can_now_change_an_entire_species_forever.
CRISPR, the disruptor. Nature. Vol. 522. June 4, 2015
CRISPR-Cas systems for editing, regulating and targeting gneomes. Nature Biotechnology 32, 347-355 (2014).