Detection and pathological value of papillomavirus DNA and p16INK4A and p53 protein expression in cervical intraepithelial neoplasia

The aim of the present study was to investigate human papillomavirus (HPV) infection and p16 INK4A and p53 protein expression, to evaluate their roles in the pathological diagnosis and grading for cervical intraepithelial neoplasia (CIN). The detection of HPV DNA and p16 INK4A and p53 protein expression were examined in a panel of clinical tissue samples using polymerase chain reaction or immunohistochemistry. In 104 cases, HPV16/18 DNA was identified in 49.0% and HPV6/11 DNA in 9.6% of cases. While in 203 cases, 74.4% positively expressed p16 INK4A and 47.3% positively expressed p53. The expression of p16 INK4A exhibited a significantly higher rate in the CIN I group than in the squamous metaplasia coupled with hyperplasia group (SMH; P<0.0001) and the CIN II-III group (P=0.005). A marked correlation was revealed between the band-like staining pattern of p16 INK4A and HPV16/18 infection. On the contrary, p53 expression was not found to significantly correlate with CIN grade or the HPV16/18 infection status. These results suggested that p16 INK4A expression correlates with a higher grade of CIN and may be used as a diagnostic marker to distinguish between CIN I and SMH, as well as between CIN I and CIN II-III.