BMI-1 autoantibody as a new potential biomarker for cervical carcinoma

PLoS One. 2011;6(11):e27804. doi: 10.1371/journal.pone.0027804. Epub 2011 Nov 21.

Abstract

BMI-1 is overexpressed in a variety of cancers, which can elicit an immune response leading to the induction of autoantibodies. However, BMI-1 autoantibody as a biomarker has seldom been studied with the exception of nasopharyngeal carcinoma. Whether BMI-1 autoantibodies can be used as a biomarker for cervical carcinoma is unclear. In this study,BMI-1 proteins were isolated by screening of a T7 phage cDNA library from mixed cervical carcinoma tissues. We analyzed BMI-1 autoantibody levels in serum samples from 67 patients with cervical carcinoma and 65 controls using ELISA and immunoblot. BMI-1 mRNA or protein levels were over-expressed in cervical carcinoma cell lines. Immunoblot results exhibited increased BMI-1 autoantibody levels in patient sera compared to normal sera. Additionally, the results for antibody affinity assay showed that there was no difference between cervical polyps and normal sera of BMI-1 autoantibody levels, but it was significantly greater in patient sera than that in normal controls (patient 0.827±0.043 and normal 0.445±0.023; P<0.001). What's more, the levels of BMI-1 autoantibody increased significantly at stage I (0.672±0.019) compared to normal sera (P<0.001), and levels of BMI-1 autoantibodies were increased gradually during the tumor progression (stage I 0.672±0.019; stage II 0.775 ±0.019; stage III 0.890 ±0.027; stage IV 1.043±0.041), which were significantly correlated with disease progression of cervical cancer (P<0.001). Statistical analyses using logistic regression and receiver operating characteristics (ROC) curves indicated that the BMI-1 autoantibody level can be used as a biomarker for cervical carcinoma (sensitivity 0.78 and specificity 0.76; AUC = 0.922). In conclusion, measuring BMI-1 autoantibody levels of patients with cervical cancer could have clinical prognostic value as well as a non-tissue specific biomarker for neoplasms expressing BMI-1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neoplasm / immunology*
  • Antibody Affinity / immunology
  • Autoantibodies / blood*
  • Bacteriophage T7
  • Biomarkers, Tumor / blood*
  • Biomarkers, Tumor / immunology
  • Disease Progression
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Gene Expression Regulation, Neoplastic
  • Gene Library
  • Humans
  • Immunohistochemistry
  • Middle Aged
  • Nasal Polyps / immunology
  • Nuclear Proteins / genetics
  • Nuclear Proteins / immunology*
  • Nuclear Proteins / metabolism
  • Polycomb Repressive Complex 1
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / immunology*
  • Proto-Oncogene Proteins / metabolism
  • Repressor Proteins / genetics
  • Repressor Proteins / immunology*
  • Repressor Proteins / metabolism
  • Uterine Cervical Neoplasms / blood*
  • Uterine Cervical Neoplasms / genetics
  • Uterine Cervical Neoplasms / immunology*

Substances

  • Antibodies, Neoplasm
  • Autoantibodies
  • BMI1 protein, human
  • Biomarkers, Tumor
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Repressor Proteins
  • Polycomb Repressive Complex 1