Drug target validation Flashcards
Why is drug target validation important in drug discovery?
Target validation confirms that modulating a target can impact disease, justifies investment into drug screening, increases the likelihood of finding effective medicines, and ensures resources focus on targets most likely to yield therapeutic benefits. It also defines the target’s role in disease, which is essential before developing drugs against it.
What are the main aspects of drug target validation?
Key aspects include: 1) Druggability assessment (confirming the target’s structure and sequence), 2) Assayability assessment (developing assays for screening small molecule modulators), and 3) Genetic assessment (studying genetic material to predict therapy efficacy and side effects).
What is “druggability” in target validation?
Druggability assesses whether a target protein has properties that allow interaction with a drug compound. This involves analyzing the protein’s 3D structure, which can be determined through X-ray crystallography, cryo-EM, or NMR.
What is “assayability” in target validation?
Assayability evaluates whether biochemical and cellular assays can be developed for high-throughput screening of compounds against the target. Assays need to validate compounds’ effects in cell and in vivo models.
How is genetic assessment used in target validation?
Genetic assessment involves studying the genetic sequence and patient genetic material to predict therapy efficacy and side effects. It examines target expression in tissues to confirm disease relevance and replicates findings in animal models.
What is CRISPR, and how does it work in genetic manipulation?
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a bacterial immune mechanism that cuts foreign DNA and incorporates fragments into CRISPR arrays for future defense. In gene editing, it uses RNA to guide Cas9 to specific DNA sequences for precise cuts.
How does CRISPR-Cas9 work in eukaryotic cells?
Cas9 uses single guide RNA (sgRNA) to target specific DNA sites based on base pairing. In gene editing, Cas9 creates DNA breaks near a PAM sequence, repaired via nonhomologous end-joining (NHEJ) or homology-directed repair (HDR), allowing gene knockouts or insertions with donor DNA.
What are the applications of CRISPR/Cas in drug discovery?
CRISPR enables early target validation by editing genes in relevant cell models, creating isogenic lines, and targeting multiple genes in pathways. It allows studying point mutations and SNPs linked to diseases, aiding in understanding disease mechanisms and validating potential drug targets.
Describe the process of target validation by CRISPR/Cas9.
1) Design sgRNAs to target specific genes, 2) Transfect sgRNAs into cells or animals, 3) Use Cas9 to knock out or knock down the gene, and 4) Analyze the effects on disease phenotypes. If gene disruption impacts the disease, it confirms the gene as a valid drug target.
What are other genetic approaches for target validation?
Other methods include gene silencing with antisense oligonucleotides, small interfering RNA (siRNA), and investigating genetic factors in clinical drug development to understand how genetic variations influence drug response.
Once a target is validated, what are the next steps in drug discovery?
The next steps include developing a biochemical assay for the target, performing high-throughput screening (either target-based or phenotypic), and identifying lead compounds that show activity against the validated target.
What are the benefits of using CRISPR for creating disease models?
CRISPR enables quick, precise model generation, including knockout mutations and isogenic cell lines, making it highly effective for studying disease mechanisms and evaluating potential drug targets. This allows researchers to target genes associated with disease phenotypes accurately.
