Cyclin A/B RxL Macrocyclic Inhibitors to Treat Cancers with High E2F Activity.
Shilpa SinghCatherine E GleasonMin FangYasmin N LaimonVishal KhivansaraShanhai XieYavuz T DurmazAniruddha SarkarKenneth NgoVarunika SavlaYixiang LiMuhannad Abu-RemailehXinyue LiBishma TuladharRanya OdehFrances Hamkins-IndikDaphne HeMiles W MembrenoMeisam NosratiNathan N GushwaSiegfried S F LeungBreena Fraga-WaltonLuis HernandezMiguel P BaldomeroBryan M LentDavid SpellmeyerJoshua F LunaDalena HoangYuliana GritsenkoManesh ChandMegan K DeMartSammy MetoboChinmay BhattJustin A ShapiroKai YangNathan J DupperAndrew T BockusJohn G DoenchJames B AggenLi-Fen LiuBernard LevinEvelyn W WangIolanda VendrellRoman FischerBenedikt KesslerPrafulla C GokhaleSabina SignorettiAlexander SpektorConstantine KreatsoulasRajinder SinghDavid J EarpPablo D GarciaDeepak NijhawanMatthew G OserPublished in: bioRxiv : the preprint server for biology (2024)
Cancer cell proliferation requires precise control of E2F1 activity; excess activity promotes apoptosis. Here, we developed cell-permeable and bioavailable macrocycles that selectively kill small cell lung cancer (SCLC) cells with inherent high E2F1 activity by blocking RxL-mediated interactions of cyclin A and cyclin B with select substrates. Genome-wide CRISPR/Cas9 knockout and random mutagenesis screens found that cyclin A/B RxL macrocyclic inhibitors (cyclin A/Bi) induced apoptosis paradoxically by cyclin B- and Cdk2-dependent spindle assembly checkpoint activation (SAC). Mechanistically, cyclin A/Bi hyperactivate E2F1 and cyclin B by blocking their RxL-interactions with cyclin A and Myt1, respectively, ultimately leading to SAC activation and mitotic cell death. Base editor screens identified cyclin B variants that confer cyclin A/Bi resistance including several variants that disrupted cyclin B:Cdk interactions. Unexpectedly but consistent with our base editor and knockout screens, cyclin A/Bi induced the formation of neo-morphic Cdk2-cyclin B complexes that promote SAC activation and apoptosis. Finally, orally-bioavailable cyclin A/Bi robustly inhibited tumor growth in chemotherapy-resistant patient-derived xenograft models of SCLC. This work uncovers gain-of-function mechanisms by which cyclin A/Bi induce apoptosis in cancers with high E2F activity, and suggests cyclin A/Bi as a therapeutic strategy for SCLC and other cancers driven by high E2F activity.
Keyphrases
- cell cycle
- cell cycle arrest
- cell death
- cell proliferation
- pi k akt
- induced apoptosis
- small cell lung cancer
- genome wide
- crispr cas
- squamous cell carcinoma
- signaling pathway
- gene expression
- dna methylation
- high throughput
- stem cells
- radiation therapy
- cell therapy
- young adults
- stress induced
- locally advanced
- rectal cancer
- dna damage
- functional connectivity
- high glucose