wo-sided, and the significance level was P<0.05. Values were expressed as means SEM. Statistical analyses were conducted using the two-tailed Student's t-test upon verification of the assumptions. MannWhitney test was used to test continuous variables for differences in NRF2 IHC scores between tumor and Chebulinic acid chemical information normal tissues. In addition, we performed Spearman’s tests for correlations. Results NRF2 and Keap1 expression in female Uighur patients with cervical cancer or CIN Antibodies were tested on formalin-fixed, paraffin-embedded, normal cervical tissues and CSCC. Representative IHC images for NRF2 and Keap1 are shown in Fig 1. NRF2 was primarily localized in the nuclei of CSCC and CIN cells. By contrast, NRF2 was mainly PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19754931 localized in the cytoplasm of normal cervical epithelial cells. Nuclear expression of NRF2 was significantly increased compared with that of cervical intraepithelial neoplasia and normal cervical epithelium. Keap1 expression was significantly decreased in the cytoplasm of cancer cells compared with that of normal cervical epithelial cells. 5 / 13 NRF2 in Cervical Cancer Fig 1. Detection of NRF2 and Keap1 protein expression assessed by immunohistochemical staining in representative specimens of PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19756449 normal cervical epithelia, CIN and CSCC, respectively. A: Expression of NRF2 in normal cervical epithelia with weak cytoplasm staining; B: Moderate expression of NRF2 protein in CIN tissue; C: Strong nucleus expression of NRF2 proteins in CSCC tissue; D: Expression of Keap1 in normal cervical epithelia with Strong cytoplasm staining; E: Moderate expression of Keap1 protein in CIN tissue; F: weak expression of Keap1 proteins in CSCC tissue.. doi:10.1371/journal.pone.0133876.g001 We correlated expression of NRF2 and Keap1 with clinical data in 89 patients with CSCC. The Mann-Whitney test was used to test differences in IHC scores between tumor and normal cervical epithelium for continuous variables. Increased expression of NRF2 was significantly associated with positive lymph node metastasis and poor differentiation. Keap1 staining correlated with tumor stage, lymph node status, and pathological grade . Methylation at single CpG sites showed significant differences between CSCC and normal cervical epithelia at CpG1, CpG3, CpG6, and CpG10, It is possible that these are binding sites for proteins that regulate Keap1 expression. Further analyze the correlation between Keap1 expressions with its DNA methylation in CSCC 
tissue; the results showed an inverse correlation of altered CpG island methylation of Keap1 with changes in protein expression. NRF2 promotes cell proliferation and apoptosis in SiHa cells NRF2-specific short hairpin or a full-length human NRF2 was successfully transfected into SiHa cells. The transfection efficiency was as high as 88.9%. Transfection efficiency of SiHa cells expressing NRF2-shRNA was assessed by flow cytometry. Expression of NRF2 was detected by real-time quantitative PCR and Western blotting. Both NRF2 mRNA and protein levels were significantly decreased after transfecting NRF2-shRNA compared with the vector control and normal groups. Conversely, NRF2 expression was significantly increased after transfecting pCDNA3.1NRF2. Using flow cytometry analysis investigates apoptosis and proliferation rates of Siha cells after altered NRF2 expression. The percentage of SiHa cells in G0/G1 phase significant increased 48 h after NRF2 knockdown compared with the percentage of control cells in G0/G1. The percentage of NRF
