Expression of Yin Yang 1 in cervical cancer and its correlation with E-cadherin expression and HPV16 E6

The molecular mechanisms of normal cervical squamous epithelium advancing to cervical intraepithelial neoplasia (CIN) and eventually to cervical squamous cell carcinoma (CSCC) are largely unknown. This study explored abnormal expression of Yin Yang 1 (YY1) in cervical cancer and its correlation with the expression of E-cadherin and human papillomavirus (HPV) 16 E6. YY1, E-cadherin and HPV16 E6 expression were detected by immunohistochemistry in 90 cervical tissue specimens collected from 30 patients with hysteromyoma, 15 patients with CIN I, 15 patients with CIN II-III, and 30 patients with CSCC. The H-score method was employed to measure the expression of YY1, E-cadherin and HPV16 E6. Increased expression of YY1 and HPV16 E6, and the decreased expression levels of E-cadherin were strongly associated with malignant transformation of the cervical epithelium and the histological progression of CSCC. The expression of YY1 in cervical tissues was inversely correlated with E-cadherin expression, and positively correlated with HPV16 E6 expression. Expression of YY1 in CSCC tissues was not significantly correlated with tumor differentiation, but was significantly correlated with an advanced clinical stage of CSCC. These results suggest that up-regulation of YY1 is closely associated with the progression of CSCC, and YY1 may play an important role in the pathogenesis of cervical cancer by modulating the expression of E-cadherin and HPV16 E6.