GENE THERAPY CLINICAL APPLICATION OF RECENT ADVANCES M.Pharmacy 1st Semester 2022 (2021-2022) Previous Year's Question Papers/Notes Download - HK Technical PGIMS

Introduction to Gene Therapy

Gene therapy involves the use of genetic material (DNA) to treat or prevent diseases by inserting functional genes into a patient's cells to replace defective or mutant alleles. The first approved gene therapy experiment took place in 1990, treating ADA-SCID (adenosine deaminase deficiency).

Key Components of Gene Therapy

1. Vectors:

   • Viral Vectors: Retroviruses, adenoviruses, adeno-associated viruses (AAV), and herpes simplex viruses (HSV) are commonly used due to their efficiency in gene delivery.

   • Non-Viral Vectors: Methods include electroporation, microinjection, gene guns, liposomes, and chemical methods like calcium phosphate transfection.

2. Gene Editing Tools:

   • Zinc Finger Nucleases (ZFNs): Bind and cleave specific DNA sequences.

   • TALENs: Offer high specificity by targeting single base pairs.

   • CRISPR-Cas9: Uses guide RNA to target and edit DNA with high precision.

Clinical Applications

Gene therapy has shown promise in treating a variety of diseases, including:

• Genetic Disorders: ADA-SCID, cystic fibrosis, thalassemia, sickle cell anemia.

• Neurological Diseases: Parkinson’s, Alzheimer’s, and Lesch-Nyhan syndrome.

• Eye Diseases: Retinal degeneration (e.g., choroideremia).

• Cancer: Strategies include oncolytic viruses, suicide gene therapy, and immune modulation (e.g., CAR-T cell therapy).

• Infectious Diseases: HIV/AIDS, where gene therapy aims to disrupt viral replication.

• Cardiovascular Diseases: Angiogenesis stimulation for coronary artery disease.

Approved Gene Therapy Products

Several gene therapy products have been approved globally, such as:

• Gendicine®: For head and neck squamous cell carcinoma.

• Luxturna®: For Leber’s congenital amaurosis.

• Zynteglo®: For beta-thalassemia.

• Yescarta®: For certain lymphomas.

Challenges and Limitations

• Technical Barriers: Efficient gene delivery, persistent gene expression, and immune responses.

• Ethical Concerns: Germline editing, accessibility, and potential misuse (e.g., cosmetic enhancements).

• Cost and Accessibility: High expenses limit widespread adoption.

Future Directions

• Expanding Applications: Beyond genetic disorders to infectious and degenerative diseases.

• Advanced Technologies: Improved vectors (e.g., safer AAV variants) and precision editing tools (e.g., base editing).

• Regulatory and Collaborative Efforts: Global standards and incentives for research and development.

Conclusion

Gene therapy represents a transformative approach in medicine, offering potential cures for previously untreatable diseases. However, challenges related to safety, ethics, and cost must be addressed to fully realize its potential. Continued innovation and collaboration will be key to advancing this field.

The Next Generation of Medicine is here, with gene therapy paving the way for groundbreaking treatments.