title: Topoisomerase I and IIalpha protein expression in primary colorectal cancer and recurrences following 5-fluorouracil-based adjuvant chemotherapy.
abstract: OBJECTIVE
  Human DNA topoisomerases I and II (topo-I and -II) are essential for vital cellular processes such as DNA replication, transcription, translation, recombination, and repair. In the present study, we correlate topo-I and -II expression and outcome after chemotherapy in primary and relapsed colorectal cancer.
  
  
  METHODS
  Patients with colorectal cancer that had recurred, following surgery and adjuvant chemotherapy and underwent a second operation were included in the present study. All had undergone surgical resection of the primary tumor and received post-operatively 5-FU-based (5FU + Leucovorin, Mayo Clinic regimen) adjuvant chemotherapy. Tumor tissue was collected at the initial operation from the primary tumor and at the time of recurrence (during the second operation following chemotherapy). All tissue samples were analyzed for levels of expression of both topo-I and topo-IIa using standard three-step immunohistochemistry on paraffin sections.
  
  
  RESULTS
  Forty patients were included. Levels of expression of topo-I and topo-II were higher in malignant cells from tumor recurrences compared to primary tumors (P = 0.0001 for both). There was a statistically significant positive relationship between patients age and levels of topo-I (P = 0.011) and topo-II (P = 0.011) expression.
  
  
  CONCLUSIONS
  The study results reported here underscore the role of topoisomerase expression in colorectal cancer and suggest a potential role in tumor recurrence.
authors.affiliation: Medical Oncology Unit, Department of Pathophysiology, Medical School, Laikon University General Hospital, National and Kapodistrian University of Athens, 11527, Athens, Greece, tsavari1@otenet.gr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Tsavaris
authors.forename: Andreas
authors.initials: A
authors.lastname: Lazaris
authors.forename: Christos
authors.initials: C
authors.lastname: Kosmas
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Gouveris
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kavantzas
authors.forename: Petros
authors.initials: P
authors.lastname: Kopterides
authors.forename: Thomas
authors.initials: T
authors.lastname: Papathomas
authors.forename: George
authors.initials: G
authors.lastname: Agrogiannis
authors.forename: George
authors.initials: G
authors.lastname: Arapogiannis
authors.forename: Haralambos
authors.initials: H
authors.lastname: Zorzos
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Kyriakou
authors.forename: Efstratios
authors.initials: E
authors.lastname: Patsouris
authors.forename: Efstathios
authors.initials: E
authors.lastname: Patsouris
mesh_terms: D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000378:metabolism*; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000601:surgery; D003131:Combined Modality Therapy; D004247:DNA / Q000235:genetics; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000201:enzymology / Q000601:surgery; D009367:Neoplasm Staging; D011003:Ploidies; D011379:Prognosis; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000951:Antigens, Neoplasm; D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D004247:DNA; D004264:DNA Topoisomerases, Type I; D004250:DNA Topoisomerases, Type II; D005472:Fluorouracil