Cancer: difficult to talk about, but even harder to cure. Unfortunately, most, if not all of us have lost loved ones due to cancer, the disease which took the lives of over 600 thousand Americans in 2022. Lymphoma, one of the most common types of cancer, is cancer of the lymphatic system, which is part of the body’s immune system and includes the lymph nodes, bone marrow, thymus gland, and spleen. Although scientists have not yet discovered a cure for it, scientists across the globe have made significant amounts of discoveries which could help treat lymphoma.
One promising treatment option is CAR (chimeric antigen receptor) T- cell therapy, discovered in 2002 by scientists at Memorial Sloan Kettering Cancer Center. As we learned in AP Biology, T-cells are part of the body’s immune system, and some (helper T-cells) recognize antigens while others (T-Killer cells) kill infected or cancerous cells. Helper T-cells recognize fragments of the antigen on the surface of macrophages and signal for the immune system to destroy the infected cell, a task that is often carried out by T-killer cells. When scientists modify T-cells in a lab by inserting a gene for a chimeric antigen receptor (CAR), the T-cells can better identify and bind to cancerous antigen fragments and signal for the body to destroy the cancer cells. After modifying the T-cells, they are inserted back into the patient.
However, one major problem with this treatment is that the T-cells often get “T-cell exhaustion,” which is when they are effective and efficient at first but quickly become worn-out and ineffective. To combat this problem, Dr. Michel Sadelain altered the T-cells’ genes through the use of CRISPR technology.
CRISPR (clustered regularly interspaced short palindromic repeats) technology is a cutting-edge method of genome editing which physically cuts and/or replaces nucleotides in DNA.
As we learned in AP Biology, DNA, the genetic “code” in every living thing, is composed of two strands, in the shape of a double helix, which are made of a phosphate and deoxyribose sugar “backbone,” and bases which attach to each sugar. There are four bases: A (adenine), T (thymine), G (guanine), and C (cytosine). A base, sugar, and phosphate together form what is called a nucleotide, and these are what CRISPR replaces or deletes.
DNA codes for all characteristics of a living organism, so when it is altered, the genetic makeup and traits change. This is an essential fact when considering CRISPR technology, since it can alter the base sequence within DNA, causing potentially life-saving gene alterations. Dr. Sadelain used this technology to insert a gene in T-cells which makes them more resilient and less prone to T-cell exhaustion. Dr. Park of Memorial Sloan Kettering recently proved Dr. Sadelain’s discovery to be effective in a clinical trial which used Sadelain’s method to use CRISPR to insert CARs and a molecule called 1XX into T-cells which were then injected into patients with lymphoma. The alterations Sadelain made were intended to create T- cells that work efficiently for longer periods of time and therefore will be more effective in destroying lymphoma cells. The results of the trial were very promising since it was very successful, safe, and used a relatively small amount of modified T-cells, meaning that the treatment could be accessible to more people if it is approved. Do you think this treatment method will be a success?
As confirmed through this trial, the capabilities of CRISPR and CAR T-cell therapy are evolving to a mind-blowing extent and are providing safer and more effective treatments for cancer and other diseases every year. Although a universal cure for cancer has not yet been discovered, the discoveries of this study could alter the future of lymphoma treatment and save the lives of thousands.
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