title: Comparison of ERCC1/XPF genetic variation, mRNA and protein levels in women with advanced stage ovarian cancer treated with intraperitoneal platinum.
abstract: OBJECTIVE
  Approximately 20% of patients receiving platinum-based chemotherapy for epithelial ovarian cancer (EOC) are refractory or develop early recurrence. Identifying these patients early could reduce treatment-associated morbidity and allow quicker transfer to more effective therapies. Much attention has focused on ERCC1 as a potential predictor of response to therapy because of its essential role in the repair of platinum-induced DNA damage. The purpose of this study was to accurately measure protein levels of ERCC1 and its essential binding partner XPF from patients with EOC treated with platinum-based therapy and determine if protein levels correlate with mRNA levels, patient genotypes or clinical outcomes.
  
  
  METHODS
  ERCC1 and XPF mRNA and protein levels were measured in frozen EOC specimens from 41 patients receiving intraperitoneal platinum-based chemotherapy using reverse transcription polymerase chain reaction and western blots. Genotypes of common nucleotide polymorphisms were also analyzed. Patient outcomes included progression free (PFS) and overall survival (OS).
  
  
  RESULTS
  Expression of ERCC1 and XPF were tightly correlated with one another at both the mRNA and protein level. However, the mRNA and protein levels of ERCC1 were not positively correlated. Likewise, none of the SNPs analyzed correlated with ERCC1 or XPF protein levels. There was an inverse correlation between mRNA levels and patient outcomes.
  
  
  CONCLUSIONS
  Neither genotype nor mRNA levels are predictive of protein expression. Despite this, low ERCC1 mRNA significantly correlated with improved PFS and OS.
authors.affiliation: School of Public Health and Health Services, The George Washington University, NW, Washington, DC 20037, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Deloia
authors.forename: Nikhil R
authors.initials: NR
authors.lastname: Bhagwat
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Darcy
authors.forename: Mary
authors.initials: M
authors.lastname: Strange
authors.forename: Chunquio
authors.initials: C
authors.lastname: Tian
authors.forename: Kevin
authors.initials: K
authors.lastname: Nuttall
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Krivak
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Niedernhofer
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D000077216:Carcinoma, Ovarian Epithelial; D002945:Cisplatin / Q000627:therapeutic use; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D018572:Disease-Free Survival; D004720:Endonucleases / Q000235:genetics* / Q000378:metabolism*; D005260:Female; D005838:Genotype; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012333:RNA, Messenger / Q000378:metabolism*; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: D000970:Antineoplastic Agents; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; C095888:xeroderma pigmentosum group F protein; C071447:ERCC1 protein, human; D004720:Endonucleases; D002945:Cisplatin