BCL-2 overexpression in follicular lymphoma protects cancer cells from apoptosis by:
- A Activating caspase-9 in the intrinsic pathway
- B Inhibiting the FAS/FASL extrinsic pathway by blocking caspase-8
- C Sequestering BAX and BAK on the mitochondrial outer membrane, preventing cytochrome c release ✓
- D Upregulating MDM2 to degrade p53
Correct answer: C. Sequestering BAX and BAK on the mitochondrial outer membrane, preventing cytochrome c release
Explanation
BCL-2 is an anti-apoptotic protein that resides on the mitochondrial outer membrane and sequesters pro-apoptotic BH3-only proteins and directly inhibits BAX/BAK oligomerisation; without BAX/BAK pores, cytochrome c cannot be released and the apoptosome (Apaf-1/caspase-9) does not form. BCL-2 does not directly affect caspase-8 or MDM2. t(14;18) juxtaposes BCL-2 to the Ig heavy chain locus in follicular lymphoma.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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