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