title: Immunocytochemical study of TOP2A and Ki-67 in cervical smears from women under routine gynecological care.
abstract: BACKGROUND
  Cervical cancer is one of the most common female cancers and is caused by human papillomavirus (HPV). Viral infection leads to cell cycle deregulation by inactivating p53 and retinoblastoma protein by viral oncoproteins E6 and E7, respectively. Then, nuclear proteins such as DNA topoisomerase type IIa (TOP2A) and Ki-67 show increased expression because of increased cell division. These molecules are used as biomarkers for immunohistochemistry analysis of cervical tissue.
  
  
  METHODS
  In this cross-sectional study, we recruited 110 women receiving regular gynecological surveillance at public health centers in Olinda - PE, Brazil. Cervicovaginal cells were collected to determine the presence of cytological abnormalities and HPV infection. Pap smear slides were used to evaluate the expression of TOP2A and Ki-67 using immunocytochemistry techniques.
  
  
  RESULTS
  Of the 110 women, 75.4 % showed HPV-DNA(+) infection (83/110) and 29.1 % showed cellular abnormalities (32/110). Two atypical cells of undetermined significance, one low-grade squamous intraepithelial lesion, and one high-grade squamous intraepithelial lesion samples showed no HPV-DNA. TOP2A was positive in 71.9 % of samples, while Ki-67 was positive in 81.2 %. Immunocytochemistry results were positive in 4 of 5 atypical cells of undetermined significance samples. In HPV-DNA(+) samples with cytological abnormalities, immunocytochemistry results were positive 96.4 % of samples (p < 0.0001; odds ratio = 28.0). Among the samples infected with HR-HPV, TOP2A(+) was effective in 71 % samples, while and Ki-67(+) was 77.4 %. Ki-67 and TOP2A were positive for all samples infected with HPV6, HPV11, and HPV18. Ki-67 was also positive for all HPV16 samples, except for one negative sample in cytopathology analysis.
  
  
  CONCLUSIONS
  TOP2A and Ki-67 antibodies may be used in combination for cervical cancer screening in immunocytochemistry assays.
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil. adryaperes@gmail.com.|Faculdade ASCES/Associação Caruaruense de Ensino Superior, Caruaru - PE, Brazil. adryaperes@gmail.com.
authors.forename: Adrya Lúcia
authors.initials: AL
authors.lastname: Peres
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Molecular Prospection and Bioinformatics Group - Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.
authors.forename: Keilla Maria
authors.initials: KM
authors.lastname: Paz E Silva
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Molecular Prospection and Bioinformatics Group - Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Department of Biochemistry, Biological Science Centre, Federal University of Pernambuco (UFPE), Recife, Brazil.
authors.forename: Rosângela Ferreira Frade
authors.initials: RF
authors.lastname: de Araújo
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Molecular Prospection and Bioinformatics Group - Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Department of Biochemistry, Biological Science Centre, Federal University of Pernambuco (UFPE), Recife, Brazil.
authors.forename: José Luiz
authors.initials: JL
authors.lastname: de Lima Filho
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Department of Pathology, Healthy Science Centre, Federal University of Pernambuco (UFPE), Recife, Brazil.
authors.forename: Mário Ribeiro
authors.initials: MR
authors.lastname: de Melo Júnior
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Molecular Prospection and Bioinformatics Group - Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Department of Biochemistry, Biological Science Centre, Federal University of Pernambuco (UFPE), Recife, Brazil.
authors.forename: Danyelly Bruneska Gondim
authors.initials: DB
authors.lastname: Martins
authors.affiliation: Laboratory of Immunopathology Keizo Asami (LIKA), Federal University of Pernambuco (UFPE), Recife, Brazil.|Department of Pathology, Healthy Science Centre, Federal University of Pernambuco (UFPE), Recife, Brazil.
authors.forename: Nicodemos Teles
authors.initials: NT
authors.lastname: de Pontes Filho
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D052685:Alphapapillomavirus; D000912:Antibodies, Neoplasm / Q000737:chemistry; D000951:Antigens, Neoplasm / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D030361:Papillomavirus Infections / Q000378:metabolism* / Q000473:pathology; D000075223:Poly-ADP-Ribose Binding Proteins; D002583:Uterine Cervical Neoplasms / Q000378:metabolism* / Q000473:pathology; D014626:Vaginal Smears
chemical_list: D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D004250:DNA Topoisomerases, Type II; C000618811:TOP2A protein, human
keywords: Cervical cytopathology; DNA Topoisomerases type IIa; Human papillomavirus; Immunocytochemistry; Ki-67 antigen