Q1. Which of the following best explains why both PANC-1 and CAPAN-2 pancreatic cancer cell lines show increased migration under hypoxia?
- Hypoxia uniformly decreases membrane stiffness in all cancer cells
- Hypoxia triggers lipid and cytoskeletal adjustments that maintain membrane malleability
- Hypoxia increases the number of mitochondria, giving cells more energy to move
- Hypoxia reduces all stiffening lipids in the plasma membrane
Correct Option: 2. Hypoxia triggers lipid and cytoskeletal adjustments that maintain membrane malleability.
Explanation:
• The studies showed that PANC-1 and CAPAN-2 respond differently at the mechanical level — PANC-1 becomes less stiff, while CAPAN-2 becomes more stiff.
• Yet, both maintain or regain membrane malleability needed for migration by adjusting lipid composition and membrane trafficking.
• This ability to re-balance membrane properties under hypoxia leads to enhanced migration.
• Options A and D are incorrect because hypoxia does not uniformly reduce stiffness or stiffening lipids; in CAPAN-2 stiffening lipids even increase.
• Option C is not supported by the research.
Q2. What was the major unexpected observation when researchers first examined the membrane properties of PANC-1 cells under hypoxia?
- The membrane completely lost its lipid content
- The broad physical properties of the plasma membrane did not change significantly
- The membrane became fully rigid despite increased migration
- The cells stopped migrating
Correct Option: 2. The broad physical properties of the plasma membrane did not change significantly.
Explanation:
• The researchers expected hypoxia-induced migration to correlate directly with major changes in membrane order or fluidity.
• Surprisingly, these broad membrane properties did not change much, leading them to analyze the lipidome composition instead.
• This deeper analysis revealed shifts in lipid types and trafficking, not large-scale membrane physical changes, were driving migration.
• Options A, C, and D are incorrect because:
– The membrane did not lose lipids (A).
– It did not become fully rigid (C).
– The cells migrated more, not less (D).