What is the primary function of most drugs in relation to disease-linked proteins?
They are inhibitors that block disease-linked proteins
What is the only definitive way to validate a target protein?
Clinical trials in humans
Why is human testing not feasible during initial drug development?
It is not feasible during initial drug development
What must potential targets undergo before drug screening?
A rigorous validation process
Why is validating drug targets crucial?
It ensures drug discovery efforts are directed against key roles in disease
What are the benefits of rigorous validation of drug targets?
- Weeds out less promising targets
- Focuses resources on high chance of therapeutic success
- Maximizes return on investment
What does drug target validation confirm?
The association between target and disease mechanisms
What are the three main aspects of drug target validation?
- Druggability assessment
- Assayability assessment
- Genetic assessment
What does druggability assessment involve?
Confirming sequence-related properties of proteins and obtaining 3D-structure using x-ray crystallography
What is involved in assayability assessment?
Ability to develop future assays for high-throughput screening
What does genetic assessment study?
Genetic sequence and patient genetic material to predict therapy efficacy and adverse effects
What technology enables high specificity in target discovery?
Novel genetic manipulation technologies based on guided nucleases
What are the modern genetic manipulation technologies mentioned?
- TALENs
- ZFNs
- CRISPR
What is the function of the CRISPR-Cas system?
An adaptive immune system in bacteria that protects against foreign DNA
What are the three major phases of the CRISPR-Cas immune system?
- Adaptation phase
- Transcription phase
- Interference phase
What is the role of Cas9 in CRISPR technology?
Uses RNA for DNA targeting and cleaves target sequences
In the absence of donor DNA, what happens during CRISPR/Cas9 editing?
The gap will be closed, leading to insertions or deletions
What is the advantage of CRISPR/Cas technology in target validation?
Allows quick and precise model generation
What is multiplex editing in the context of CRISPR technology?
Targeting multiple genes within a pathway
What are the steps to validate a drug target using CRISPR/Cas9?
- Design and synthesize CRISPR guide RNAs (sgRNAs)
- Transfect sgRNAs into cells or animals
- Knock out or knock down the drug target gene
- Analyze effects on disease-relevant phenotypes
What does a successful knockout or knockdown of a drug target gene indicate?
Provides strong evidence that the gene is a valid drug target
What are the next steps once a drug target is validated?
- Validate biochemical assay
- Use high-throughput screening approaches
- Lead identification
What is the difference between target-based screening and phenotypic screening?
- Target-based screening: tests compound libraries against the validated target
- Phenotypic screening: screens for compounds inducing desired phenotypic changes
