A 58-year-old man with newly diagnosed acute myeloid leukemia presents with fatigue, petechiae, and bleeding gums. Laboratory studies show WBC 87,000/μL and hemoglobin 7.2 g/dL. His leukemic cells are treated with an experimental histone deacetylase inhibitor. Chromatin analysis reveals increased acetylation of histone proteins and reactivation of transcription in previously silenced tumor suppressor gene regions. Which of the following best explains the mechanism underlying this therapeutic effect?
- A)Histone acetylation loosens chromatin and promotes transcriptionGABARITO
- B)Histone acetylation condenses chromatin and represses transcription
- C)Telomere shortening activates proto oncogenes
- D)Restriction enzyme cleavage increases translation
- E)DNA methylation always activates gene expression
Explicação
Histone acetylation neutralizes positive charges on histones, decreasing their interaction with negatively charged DNA and opening chromatin for transcription. Histone deacetylase inhibition therefore increases acetylation and can reactivate silenced genes. Th... Ver explicação completa e trilha adaptativa →