Rewriting the Code: How Gene Therapy is Transforming Cancer Treatment
Makayla Anderson · Oncology Editor in Chief at Revitalised Medicine
9 May 2025
Cancer begins with a genetic mistake—cells that grow when they shouldn't, refusing to die when they should, often due to mutations in genes controlling cell division and repair. What if we could correct those errors directly at the source?This question lies at the heart of gene therapy, a rapidly evolving field in oncology that seeks to alter or replace malfunctioning genes to treat or even cure cancer. Once seen as a distant dream, gene therapy is now producing real results, offering hope to patients facing aggressive or treatment-resistant cancers.
A dual-intron targeting mechanism using CRISPR-cas9 disrupts the RUNX1-RUNX1T1 fusion gene, which causes a shift in the nucleotide base reading frame, resulting in a premature stop codon to arise and hence, a nonfunctional oncogene. This results in decreased proliferation and tumor volume (Neldeborg et al.).
The Science Behind Gene Therapy in Oncology
Gene therapy involves introducing, removing, or altering genetic material within a patient's cells. In oncology, this can be used to:Inactivate Oncogenes
Oncogenes are like faulty gas pedals in a car — they make cells grow and divide too fast, which can lead to cancer. Scientists are working on ways to "turn off" these genes so they stop fueling cancer growth.Restore Tumor Suppressor Genes
Tumor suppressor genes act like brakes for cell growth, keeping things under control. But in cancer, these brakes often get damaged. Restoring them helps the body regain control, slowing down or stopping the spread of cancer cells.Enhance Immune Responses
Normally, your immune system can spot and destroy harmful cells — but cancer cells can hide. By modifying immune cells (like T cells), scientists help them better recognize and attack cancer, almost like giving them a better set of instructions to find the enemy.Early gene therapies used viral vectors to deliver corrected genes to cells. More recently, CRISPR-Cas9 and other gene-editing tools have enabled precise modifications, reducing off-target effects and improving safety.Clinical Trials Making a Difference
One landmark example is the CAR-T cell therapy trials targeting acute lymphoblastic leukemia (ALL) and diffuse large B-cell lymphoma. In these trials, researchers extracted a patient’s T-cells, genetically engineered them to express a receptor (CAR) that recognizes cancer cells, and reintroduced them into the body. The results were groundbreaking—some patients with relapsed ALL achieved long-term remission.Another pivotal trial focused on p53 gene replacement therapy. p53, known as the “guardian of the genome,” is mutated in over half of all cancers. By delivering functional p53 genes via adenoviral vectors, researchers observed tumor shrinkage in head and neck cancers. While not yet widely adopted in the U.S., it signaled the potential of gene therapy to directly repair genetic defects in cancer.Challenges and Future Directions
Gene therapy isn’t a silver bullet—yet. Delivery remains a major hurdle: getting therapeutic genes into the right cells without triggering immune responses or unintended changes. There are also ethical and safety concerns around germline editing and off-target effects.These are some examples of treatments:
Personalized Gene Editing:
Scientists are working on ways to fix genes based on a person’s exact DNA changes. This could help treatments work better and be safer.Non-Viral Delivery Methods
Instead of using viruses to carry helpful genes into the body, researchers are using tiny fat-like particles. These were used in COVID-19 vaccines and are a safer way to deliver gene treatments.Gene Silencing (RNA Interference):
This method doesn’t change genes but turns off ones that cause problems. It uses small pieces of RNA to block bad genes from doing harm.Why This Matters
As someone deeply passionate about oncology, I see gene therapy not just as a treatment, but as a paradigm shift in how we understand and combat cancer. It’s a field where science fiction is turning into clinical reality—where editing DNA could mean extending life.While challenges remain, the momentum is clear. The future of oncology is being written in our genes, and we’re learning how to hold the pen.ReferencesAmerican Society of Gene and Cell Therapy (ASGCT) – Covers gene therapy techniques, including viral and non-viral delivery methods, and updates on clinical trials.
Source: American Society of Gene and Cell Therapy. “Gene Therapy Basics” and “Clinical Trials.”National Cancer Institute (NCI) – Offers detailed explanations on oncogenes, tumor suppressor genes, and the role of genetic mutations in cancer.
Source: National Cancer Institute. “Cancer Genes and Gene Therapy.”Nature Reviews Cancer – Offers comprehensive reviews on CRISPR-Cas9 technology, RNA interference, and tumor suppressor gene research.
Source: Nature Reviews Cancer. “CRISPR–Cas9 in cancer research and therapy.”New England Journal of Medicine (NEJM) – Published landmark studies on CAR-T cell therapies for leukemia and lymphoma.
Source: NEJM. “Chimeric Antigen Receptor T Cells in Refractory B-Cell Lymphomas.”World Health Organization (WHO) – Discusses global gene therapy developments, including international trials like Gendicine.
Source: WHO. “Gene Therapy and Global Cancer Treatment Efforts.”