Screening models for anticancer drugs MCQs With Answer

Introduction
Screening models for anticancer drugs are essential tools B. Pharm students must understand to bridge pharmacology and drug discovery. Key models include in vitro cell lines, 3D spheroids, patient-derived organoids, and in vivo xenografts and genetically engineered mouse models. High-throughput screening (HTS), IC50 determination, mechanism-based cytotoxicity assays, and ADMET profiling enable identification and optimization of leads. Understanding assay selection, tumor microenvironment simulation, biomarkers, and ethical considerations improves interpretation of efficacy and selectivity data. Mastery of these screening models—advantages, limitations, and readouts—prepares students for rational anticancer drug development. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which in vitro model best preserves three-dimensional tumor architecture and cell–cell interactions for anticancer drug screening?

• Monolayer 2D cell culture
• 3D tumor spheroids
• Cell-free biochemical assay
• Yeast expression system

Correct Answer: 3D tumor spheroids

Q2. What does IC50 represent in anticancer drug screening?

• The maximum drug concentration tolerated in animals
• The concentration that increases proliferation by 50%
• The concentration that inhibits 50% of a measured biological activity
• The concentration needed for complete tumor regression

Correct Answer: The concentration that inhibits 50% of a measured biological activity

Q3. Which assay is commonly used to measure cell metabolic activity as a surrogate for viability?

• MTT assay
• Transwell invasion assay
• TUNEL assay
• Tube formation assay

Correct Answer: MTT assay

Q4. Patient-derived xenografts (PDX) are valued because they:

• Are inexpensive and high-throughput
• Completely replace the need for in vitro testing
• Preserve patient tumor heterogeneity and stromal interactions
• Are genetically identical to cell lines

Correct Answer: Preserve patient tumor heterogeneity and stromal interactions

Q5. Which model allows genetic manipulation to study oncogene function and tumor initiation in vivo?

• 2D primary cell culture
• Genetically engineered mouse models (GEMMs)
• Organotypic slice culture
• Yeast two-hybrid system

Correct Answer: Genetically engineered mouse models (GEMMs)

Q6. In high-throughput screening (HTS), the Z’-factor is used to:

• Measure effective drug half-life in vivo
• Assess assay quality and separation between positive and negative controls
• Determine IC50 from dose-response curves
• Calculate selectivity index for cytotoxic drugs

Correct Answer: Assess assay quality and separation between positive and negative controls

Q7. Which assay specifically measures the ability of cancer cells to form colonies after drug exposure?

• Clonogenic assay
• ELISA for VEGF
• Flow cytometric cell cycle analysis
• MTT metabolic assay

Correct Answer: Clonogenic assay

Q8. Organoids differ from spheroids primarily because organoids:

• Are simpler and lack differentiation
• Are derived from stem cells and recapitulate tissue architecture
• Are cell-free matrices used for biochemical assays
• Require no extracellular matrix support

Correct Answer: Are derived from stem cells and recapitulate tissue architecture

Q9. Which in vitro assay is commonly used to assess apoptosis by detecting DNA fragmentation?

• TUNEL assay
• SRB assay
• Transwell migration assay
• Tube formation assay

Correct Answer: TUNEL assay

Q10. A major limitation of traditional 2D monolayer cultures in drug screening is:

• Their excessive resemblance to in vivo tumors
• Failure to mimic tumor microenvironment and gradients
• High cost and low reproducibility
• Inability to measure IC50 values

Correct Answer: Failure to mimic tumor microenvironment and gradients

Q11. Which model offers rapid, in vivo visualization of tumor growth and drug effects in larvae?

• Zebrafish xenograft model
• Rat subcutaneous tumor model
• Yeast expression model
• In vitro organoid culture

Correct Answer: Zebrafish xenograft model

Q12. Selectivity index in anticancer screening compares:

• Drug solubility versus permeability
• IC50 in cancer cells to IC50 in normal cells
• In vivo dose to in vitro potency
• Metabolic stability across species

Correct Answer: IC50 in cancer cells to IC50 in normal cells

Q13. Which readout is best for assessing effects on cell proliferation rate?

• BrdU or EdU incorporation assays
• Tube formation assay
• TUNEL staining
• Transwell invasion assay

Correct Answer: BrdU or EdU incorporation assays

Q14. Phenotypic screening differs from target-based screening because it:

• Requires prior knowledge of a molecular target
• Assesses cellular or organismal phenotype without predefined target
• Is limited to biochemical enzyme assays
• Cannot be used in HTS formats

Correct Answer: Assesses cellular or organismal phenotype without predefined target

Q15. ADMET profiling in early anticancer development addresses:

• Only the mechanism of action
• Absorption, distribution, metabolism, excretion, and toxicity
• Just in vitro cytotoxicity
• Statistical aspects of assay design

Correct Answer: Absorption, distribution, metabolism, excretion, and toxicity

Q16. Which assay measures invasive potential of tumor cells through extracellular matrix components?

• Transwell invasion assay with Matrigel
• Clonogenic assay
• MTT metabolic assay
• ELISA for caspase-3

Correct Answer: Transwell invasion assay with Matrigel

Q17. For mechanistic studies of apoptosis, which marker is often measured?

• Activated caspase-3
• VEGF secretion
• Actin polymerization
• Glucose uptake

Correct Answer: Activated caspase-3

Q18. A major ethical advantage of using 3D in vitro models and organoids is:

• They remove all variability seen in human tumors
• They can reduce the number of animals used in preclinical testing
• They are always more predictive than any animal model
• They are exempt from regulatory validation

Correct Answer: They can reduce the number of animals used in preclinical testing

Q19. Which assay directly evaluates angiogenesis in vitro by endothelial tube formation?

• Tubule (tube) formation assay on Matrigel
• Colony forming assay
• Comet assay for DNA damage
• BrdU incorporation

Correct Answer: Tubule (tube) formation assay on Matrigel

Q20. What is an advantage of high-content screening (HCS) over simple viability assays?

• HCS provides multiplexed, image-based phenotypic data per cell
• HCS requires no instrumentation
• HCS is cheaper and lower throughput than MTT
• HCS cannot measure subcellular changes

Correct Answer: HCS provides multiplexed, image-based phenotypic data per cell

Q21. Which metric describes reproducibility and signal window for an assay used in HTS?

• Z’-factor
• LD50
• Cmax
• LogP

Correct Answer: Z’-factor

Q22. Drug resistance mechanisms that can be studied in screening models include:

• Efflux pump overexpression and DNA repair upregulation
• Only changes in drug color
• Viral contamination of cultures
• Loss of assay reagents

Correct Answer: Efflux pump overexpression and DNA repair upregulation

Q23. Which in vitro test helps assess potential cardiotoxicity risk of anticancer candidates?

• hERG channel inhibition assay
• Transwell migration assay
• Clonogenic survival assay
• MTT on hepatocytes only

Correct Answer: hERG channel inhibition assay

Q24. Patient-derived organoids are particularly useful for:

• High-throughput chemical synthesis
• Personalized medicine and predicting patient drug response
• Replacing all clinical trials
• Measuring plasma protein binding

Correct Answer: Personalized medicine and predicting patient drug response

Q25. Which factor is critical when translating in vitro potency to in vivo efficacy?

• Drug pharmacokinetics and tumor penetration
• Color of the drug solution
• Number of authors on the publication
• Assay vendor brand

Correct Answer: Drug pharmacokinetics and tumor penetration

Q26. Which model is most appropriate for studying tumor–immune interactions in vivo?

• Syngeneic mouse tumor models with competent immune system
• Immunodeficient mouse xenografts only
• Yeast fermentation systems
• Cell-free enzyme assays

Correct Answer: Syngeneic mouse tumor models with competent immune system

Q27. A dose–response curve with a shallow slope suggests:

• High variability or heterogeneous response among cells
• Complete insensitivity to the drug
• Perfect, uniform drug action
• That the drug is a strong irreversible inhibitor

Correct Answer: High variability or heterogeneous response among cells

Q28. Which assay is used to detect DNA damage induced by genotoxic anticancer agents?

• Comet assay (single-cell gel electrophoresis)
• MTT assay for viability
• Tubule formation assay
• Transwell invasion without matrix

Correct Answer: Comet assay (single-cell gel electrophoresis)

Q29. When selecting cell lines for screening, it is important to consider:

• Genetic background, relevant mutations, and phenotype
• Only the cheapest available line
• Whether the line grows in the dark
• Manufacturer marketing claims alone

Correct Answer: Genetic background, relevant mutations, and phenotype

Q30. During lead optimization, which property is NOT a primary focus?

• Enhancing pharmacodynamic potency and reducing toxicity
• Improving ADMET and selectivity
• Scaling up to clinical manufacturing without preclinical validation
• Enhancing tumor penetration and metabolic stability

Correct Answer: Scaling up to clinical manufacturing without preclinical validation

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com