Author: Ella Chen
Editor: Hwi-On Lee and Sophia Chen
Artist: Chiara Chen
Genome editing is a technology that allows scientists to modify the DNA of organisms, either by inserting, deleting, or replacing DNA sequences. Several gene editing technologies have been developed over the years, with the most efficient being CRISPR. CRISPR, or Clustered Regularly Interspaced Short Palindromic Repeats, is a groundbreaking technology developed by research scientists that works with a CRISPR-associated enzyme (Cas9) to cut DNA at targeted areas. With the development of CRISPR, previously incurable genetic disorders such as sickle cell disease now have potential cures, revealing the future potential that CRISPR holds for disease treatment.
CRISPR is relatively user-friendly and involves a straightforward process. To alter the DNA, researchers first have to identify the DNA sequence they intend to modify. Subsequently, they design and synthesize a guide RNA (gRNA) complementary to the target DNA sequence, enabling the guide RNA to identify the sequence. Once the guide RNA is synthesized, it attaches to the Cas9 protein, which will cut the DNA. This combination is called the CRISPR-Cas9 complex. The CRISPR-Cas9 complex is introduced into the target organism, where it seeks out a Protospacer Adjacent Motif (PAM) sequence NGG, with N representing any nucleotide base and G representing guanine. Upon locating a PAM sequence, it will check if the DNA sequence next to it is the one that it's looking for. If it is not, it will keep looking for other PAM sequences. However, if it is, the CRISPR-Cas9 complex will cut the DNA at the targeted sequence. After the DNA is cut, scientists can make their desired changes. Since CRISPR’s development, scientists have found various ways to apply CRISPR’s versatility to scientific fields, ranging from gene therapy to agricultural advancements.
CRISPR’s use in the treatment of diseases has proven to be remarkable, showcasing the substantial impact that CRISPR has on the future of medical treatment. Recently, the U.S. Food and Drug Administration approved Casgevy, a gene therapy that utilizes CRISPR to treat sickle cell disease in patients. Sickle cell disease is a mutation in hemoglobin, the protein that carries oxygen throughout the body, which causes red blood cells to become “sickle”, or crescent-shaped, instead of the regular disk shape. The sickled red blood cells can block blood flow to the body’s tissues, leading to organ problems. Previously, the only cure for sickle cell disease was a bone marrow transplant, which involves significant risks. But now, with CRISPR, treating sickle cell disease is more promising; in the trial for the effectiveness and safety of Casgevy, all treated patients successfully engrafted, producing healthy red blood cells.
Though there is still much progress to be made, CRISPR has presented itself as a highly favorable method of treatment for incurable diseases. It represents future advancements in medicine and is slowly changing genetic research for the better. Thanks to CRISPR and other gene-editing technologies, people with rare diseases can now embrace a renewed sense of hope.
Citations:
“FDA Approves First Gene Therapies to Treat Patients with Sickle Cell Disease.” FDA, 8
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“Gene Editing Mechanism of CRISPR-Cas9.” Wyss Institute, 18 Aug.
2017, https://wyss.harvard.edu/media-post/gene-editing-mechanism-of-crispr-cas9/
National Cancer Institute. “How CRISPR Is Changing Cancer Research and Treatment -
National Cancer Institute.” Www.cancer.gov, National Cancer Institute, 27 July 2020,
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Peebles, Angelica. “U.S. Approves First Gene-Editing Treatment, Casgevy, for Sickle Cell
Disease.” CNBC, 8 Dec. 2023, www.cnbc.com/2023/12/08/casgevy-first-crispr-gene-
editing-treatment-approved-in-us.html.
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