title: Ribavirin treatment effects on breast cancers overexpressing eIF4E, a biomarker with prognostic specificity for luminal B-type breast cancer.
abstract: OBJECTIVE
  We have evaluated the eukaryotic translation initiation factor 4E (eIF4E) as a potential biomarker and therapeutic target in breast cancer. eIF4E facilitates nuclear export and translation of specific, growth-stimulatory mRNAs and is frequently overexpressed in cancer.
  
  
  METHODS
  Breast cancer cells were treated with ribavirin, an inhibitor of eIF4E, and effects on cell proliferation and on known mRNA targets of eIF4E were determined. eIF4E expression was assessed, at the mRNA and protein level, in breast cancer cell lines and in skin biopsies from patients with metastatic disease. Additionally, pooled microarray data from 621 adjuvant untreated, node-negative breast cancers were analyzed for eIF4E expression levels and correlation with distant metastasis-free survival (DMFS), overall and within each intrinsic breast cancer subtype.
  
  
  RESULTS
  At clinically relevant concentrations, ribavirin reduced cell proliferation and suppressed clonogenic potential, correlating with reduced mRNA export and protein expression of important eIF4E targets. This effect was suppressed by knockdown of eIF4E. Although eIF4E expression is elevated in all breast cancer cell lines, variability in ribavirin responsiveness was observed, indicating that other factors contribute to an eIF4E-dependent phenotype. Assessment of the prognostic value of high eIF4E mRNA in patient tumors found that significant discrimination between good and poor outcome groups was observed only in luminal B cases, suggesting that a specific molecular profile may predict response to eIF4E-targeted therapy.
  
  
  CONCLUSIONS
  Inhibition of eIF4E is a potential breast cancer therapeutic strategy that may be especially promising against specific molecular subtypes and in metastatic as well as primary tumors.
authors.affiliation: Lady Davis Institute & Segal Cancer Centre of the Jewish General Hospital, McGill University, Montréal, Canada.
authors.forename: Filippa
authors.initials: F
authors.lastname: Pettersson
authors.forename: Christina
authors.initials: C
authors.lastname: Yau
authors.forename: Monica C
authors.initials: MC
authors.lastname: Dobocan
authors.forename: Biljana
authors.initials: B
authors.lastname: Culjkovic-Kraljacic
authors.forename: Hélène
authors.initials: H
authors.lastname: Retrouvey
authors.forename: Hélène
authors.initials: H
authors.lastname: Retrouvay
authors.forename: Rachel
authors.initials: R
authors.lastname: Puckett
authors.forename: Ludmila M
authors.initials: LM
authors.lastname: Flores
authors.forename: Ian E
authors.initials: IE
authors.lastname: Krop
authors.forename: Caroline
authors.initials: C
authors.lastname: Rousseau
authors.forename: Eftihia
authors.initials: E
authors.lastname: Cocolakis
authors.forename: Katherine L B
authors.initials: KL
authors.lastname: Borden
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Benz
authors.forename: Wilson H
authors.initials: WH
authors.lastname: Miller
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism; D001943:Breast Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy* / Q000235:genetics; D002277:Carcinoma / Q000145:classification / Q000175:diagnosis* / Q000188:drug therapy* / Q000235:genetics; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D039561:Eukaryotic Initiation Factor-4E / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D042361:Mammary Glands, Human / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity / Q000235:genetics; D011379:Prognosis; D034741:RNA, Small Interfering / Q000494:pharmacology; D012254:Ribavirin / Q000494:pharmacology / Q000627:therapeutic use*; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D039561:Eukaryotic Initiation Factor-4E; D034741:RNA, Small Interfering; D012254:Ribavirin