Increased expression of oncogene-induced senescence markers during cervical squamous cell cancer development.

PURPOSE: To investigate the expression of p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) in specimens from cases of normal cervical epithelium (NCE), cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC), and to evaluate whether there is evidence implicating oncogene-induced senescence (OIS) in cervical squamous cell cancer development.

METHODS

The immunohistochemical expression of p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) were investigated in formalin-fixed paraffin-embedded specimens from 19 NCE, 51 CIN and 21 SCC cases, respectively. Comparisons among different groups for each marker were performed with Chi-square test.

RESULTS

The expression of p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) were significantly higher in both CIN and SCC compared to NCE. Furthermore, the expression of p15(INK4b) and p21(Waf1/Cip1) was significantly higher in CIN П compared to CIN І, and these expressions were statistically higher in CIN Ш compared to CIN П, respectively. The p16(INK4a) expression was significantly higher in CIN Ш compared to CIN І.

CONCLUSIONS

The results suggested that the senescence programs mediated by p15(INK4b), p16(INK4a) and p21(Waf1/Cip1) were activated during the stage of CIN and SCC, and demonstrated that senescence may play important role in preventing from NCE to SCC.