Exploring Precision Medicine
What is precision medicine?• An emerging approach for disease treatment and prevention that
takes into account individual variability in genes, environment, and lifestyle for each person
• Allow doctors and researchers to predict more accurately which treatment and prevention strategies for a particular disease will work in which groups of people.
• The “one size fits all” approach the medicine is not always effective
Cancer Treatment
Learning Outcomes
• Describe the relationship between SNPs and gene expression
• Explain how the gene TAS2R38 impacts taster phenotype
• Model the process of PCR and explain its components
• Provide examples of how DNA sequencing may impact medicine in the future
• Recognize the connection between genetics and drug metabolism
Medicine: A Complex Puzzle
• Asthma is a very common condition that affects the respiratory system and makes it extremely difficult for a patient to breathe
• Researchers believe asthma has a strong genetic component that can be further exacerbated by environmental conditions
Storyline Overview
• Medications Are Not One-Size-Fits-All
• DNA, SNPs and Drugs
• Personalization: The Future of Medicine?
• TAS2R38: A Vehicle for Understanding the Genotype-Phenotype Relationship
DNA Extraction - Chelex Resin
• Produced by Bio-Rad, 500 g = $856
• Binds to metal ions, including Mg2+ (magnesium ions)
• DNAase enzymes degrade DNA in the cytoplasm• need to Mg2+ function
Amplifying PTC DNA by Polymerase Chain Reaction (PCR)
1. PCR Master Mix (22.5 uL) and DNA (2.5 uL) in PCR tube
• Gene specific primers – locate the PTC gene
• dNTPs (mixture of A T C G nucleotides)
• Salts – neutralize the electrically charged sugar phosphate backbone
• pH of 8.9
• One Taq DNA Polymerase
2. Perform PCR Amplification using miniPCR Thermocycler
PTC Gene• Ability to taste PTC (phenylthiocarbamide) is an inherited dominant trait
• Varies in the human population and influences taste
• PTC taste receptor gene is TAS2R38 (located on chromosome 7) – bitter tasting ability
• PTC gene is just one of 30 bitter taste receptors on the tongue
Single Nucleotide Polymorphism (SNP)
• SNPs are common genetic variations
• A SNP represents a variation in a single nucleotide of a gene
• Use HaeIII restriction enzyme to recognize the SNP sequence of the PTC gene
GGCC
Single Nucleotide Polymorphism (SNP)
• Identify subtle differences in DNA and how they affect you
Amplifying PTC DNA by Polymerase Chain Reaction (PCR)
Another Dramatic PCR Animation