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RESEARCH PRODUCT
ER+ Breast Cancers Resistant to Prolonged Neoadjuvant Letrozole Exhibit an E2F4 Transcriptional Program Sensitive to CDK4/6 Inhibitors
Monica V. EstradaThomas StrickerKatherine E. HutchinsonJ. Alejandro Pérez-fidalgoValerie M. JansenMonica ArnedosLuis J. SchwarzAna LluchJennifer M. GiltnaneAmparo Ruiz-simonFabrice AndreV. GuillemKyungmin LeeMohamed Amine BayarMohamed Amine BayarAngel Guerrero-zotanoCarlos L. ArteagaStefan MichielsStefan MichielsAlberto ServettoDaniel G. StoverJoaquín GaviláLuigi FormisanoAntonio Llombart-cussacsubject
0301 basic medicineCancer ResearchBreast NeoplasmsE2F4 Transcription FactorArticle03 medical and health sciences0302 clinical medicineText miningDownregulation and upregulationCell Line TumorBiomarkers TumormedicineHumansEndocrine systemProtein Kinase InhibitorsE2F4GeneAgedCell ProliferationAged 80 and overAromatase Inhibitorsbusiness.industryGene Expression ProfilingLetrozoleEndocrine therapyComputational BiologyMiddle AgedEMTREE drug terms: aromatase inhibitorcyclin dependent kinase 4cyclin dependent kinase 6cyclin dependent kinase inhibitorfulvestrantletrozolepaclitaxelpalbociclibtranscription factor E2F4estrogen receptorletrozoleprotein kinase inhibitortranscription factor E2F4transcriptometumor marker030104 developmental biologyReceptors EstrogenOncologyDrug Resistance Neoplasm030220 oncology & carcinogenesisLetrozoleMutationRetreatmentCancer researchFemaleTranscriptomebusinessmedicine.drugdescription
AbstractPurpose: This study aimed to identify biomarkers of resistance to endocrine therapy in estrogen receptor–positive (ER+) breast cancers treated with prolonged neoadjuvant letrozole.Experimental Design: We performed targeted DNA and RNA sequencing in 68 ER+ breast cancers from patients treated with preoperative letrozole (median, 7 months).Results: Twenty-four tumors (35%) exhibited a PEPI score ≥4 and/or recurred after a median of 58 months and were considered endocrine resistant. Integration of the 47 most upregulated genes (log FC > 1, FDR < 0.03) in letrozole-resistant tumors with transcription-binding data showed significant overlap with 20 E2F4-regulated genes (P = 2.56E−15). In patients treated with the CDK4/6 inhibitor palbociclib before surgery, treatment significantly decreased expression of 24 of the 47 most upregulated genes in letrozole-resistant tumors, including 18 of the 20 E2F4 target genes. In long-term estrogen-deprived ER+ breast cancer cells, palbociclib also downregulated all 20 E2F4 target genes and P-RB levels, whereas the ER downregulator fulvestrant or paclitaxel only partially suppressed expression of this set of genes and had no effect on P-RB. Finally, an E2F4 activation signature was strongly associated with resistance to aromatase inhibitors in the ACOSOG Z1031B neoadjuvant trial and with an increased risk of relapse in adjuvant-treated ER+ tumors in METABRIC.Conclusions: In tumors resistant to prolonged neoadjuvant letrozole, we identified a gene expression signature of E2F4 target activation. CDK4/6 inhibition suppressed E2F4 target gene expression in estrogen-deprived ER+ breast cancer cells and in patients' ER+ tumors, suggesting a potential benefit of adjuvant CDK4/6 inhibitors in patients with ER+ breast cancer who fail to respond to preoperative estrogen deprivation. Clin Cancer Res; 24(11); 2517–29. ©2018 AACR.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-01-01 |