Association of human papillomavirus type 16 E7 and HLA class I antigen expression in cervical premalignant and malignant lesions.

In the present experiment we studied the correlation between HPV16 infection and expression of HLA-I antigen in cervical premalignant and malignant lesions (cervicitis, CIN, cervical squamous carcinomas and adenocarcinoma samples). The HPV16 E7 DNA load and the expression of HLA-I antigen in the samples were measured by real-time fluorescence quantitative polymerase chain reaction (RFQ-PCR) and immunohistochemical S-P staining, respectively. Our data indicate that HPV16 E7 load was highly and positively associated with the development of cervical lesions (Spearman's correlation coefficient r=0.848, p<0.001), the negative rate of HLA-I antigen was significantly distinguished among groups (p<0.001), and HPV16 E7 infection and downregulation of HLA-I antigen were highly correlated in cervical lesions (Pearson's correlation coefficient r=-0.487, p<0.001). HPV16 E7 may play an important role in the downregulation of HLA-I antigen in cervical lesions, which results in the immune escape of the virus and the occurrence, development, invasion and metastasis of cancer. Furthermore, quantitative PCR for HPV16 E7 may play an important role in the early detection of cervical diseases and in guiding future therapy toward prevention.