BTEC 1322 Chapter 11 - Medical Biotechnology

Medical Biotechnology Overview

Model organisms are crucial for understanding human genetics and diseases due to ethical and legal restrictions on manipulating human genetics.
Many genes are conserved across different species, allowing researchers to study homologous genes in model organisms (e.g., fruit flies, yeast).
Gene knockouts and genome editing (e.g., CRISPR-Cas) in model organisms help elucidate gene function related to human diseases.
Genetic similarities: Humans share 50% to 90% of their genes with various organisms.

Human Genome Project (HGP): Fundamental for detecting genetic diseases and developing medical treatments.
Biomarkers: Critical for early disease detection. For example:
- Prostate-specific antigen (PSA): Elevated in prostate inflammation and cancer.
- Chronic traumatic encephalopathy (CTE): Requires autopsy for diagnosis.
- Circulating tumor DNA (ctDNA) and protein microarrays used for early disease detection.
Genetic Testing: Methods for identifying chromosomal abnormalities and mutations. Key tests:
1. Amniocentesis: Tests fetal cells obtained from amniotic fluid around 16 weeks.
2. Chorionic Villus Sampling (CVS): Faster than amniocentesis, performed at 8-10 weeks.
3. Noninvasive Prenatal Genetic Diagnosis (NIPD): Uses fetal cells in maternal blood.
Techniques Used: Fluorescent in situ hybridization (FISH) and allele-specific oligonucleotide (ASO) analysis for detecting specific mutations.
SNPs: Common genetic variations that can affect disease susceptibility.

Personal Genomics: Whole-genome sequencing is becoming common, but quality control and data privacy remain concerns.
Whole-Exome Sequencing (WES): Used to identify diseases through coding sequence examination; encouraged by NIH for undiagnosed diseases.
Single-Cell Sequencing (SCS): Allows genomic and gene expression analysis at the single-cell level.
Genome-Wide Association Studies (GWAS): Investigates genetic variations in populations to identify disease-associated genes.

Precision Medicine Initiative (PMI): Focuses on individualized treatment based on genetics and other personal factors.
Pharmacogenetics: Tailors drug treatment based on genetic profile, helping avoid adverse reactions.
- Example: Herceptin for certain breast cancers.

Gene Therapy: Involves delivering therapeutic genes to correct genetic disorders through various methods:
1. Ex vivo: Cells are modified outside the body before re-introduction.
2. In vivo: Directly introducing genes into the patient’s cells.
Vectors: Viruses are often used as delivery mechanisms for gene therapy.
- Potential gene therapy targets include single-gene mutations in diseases like cystic fibrosis and hemophilia.
- Challenges include delivery mechanisms and gene expression control.

Regenerative Medicine: Focuses on repairing or replacing damaged tissues or organs using various technologies, including:
- Fetal tissue transplants for neurodegenerative conditions.
- Cellular therapeutics delivering healthy cells to damaged areas.
- Tissue Engineering: Building scaffolds for cell growth and 3D bioprinting of tissues.
Stem Cells: Essential for regenerative medicine; can be obtained from various sources.
- Embryonic Stem Cells (hESCs): Pluripotent and capable of becoming diverse cell types, with potential in therapies.
- Induced Pluripotent Stem Cells (iPSCs): Created from adult cells through nuclear reprogramming.
Cloning: Differentiates between reproductive cloning (creating organisms) and therapeutic cloning (tissue generation).

Research is regulated by various ethical guidelines and governmental standards, which have evolved with public sentiments towards stem cells and cloning.