OBJECTIVETo investigate the expression and clinical significance of enhancer of zeste homolog 2 (EZH2) and p53 proteins in cervical squamous cell carcinoma (SCC) and cervical intraepithelial neoplasia (CIN).

METHODSThe expression and distribution of EZH2 and p53 were determined with reference to clinicopathological features and patient survival. 168 cervical SCC, 19 CINII, 35 CINIII patients and 30 normal control cases were collected for immunohistochemical analysis.

RESULTSThe expression of EZH2 in the normal cervix, CIN and SCC was 6.7% (2/30), 37.0% (20/54) and 75.6% (127/168), respectively, with a significant difference between them (P < 0.05). The expression of p53 was 3.3% (1/30), 20.4% (11/54) and 39.3% (66/168), respectively, also (P < 0.05). In the 168 SCC cases, the positive rate of EZH2 in the cases with lymph node metastasis was 82.9%, and that of p53 was 45.7%; the positive rate of EZH2/p53 protein expression in the cases with negative lymph nodes was 70.4%, and that of p53 was 34.7%, with a significant difference between the two subgroups (P < 0.05). Among the 143 followed-up SCC patients, the EZH2(+) p53(+) cases had a progression-free survival of (51.3 ± 3.8) months, that of EZH2(+) or p53(+) cases was (66.1 ± 2.0) months, and that of EZH2(-) p53(-) cases was (71.3 ± 1.9) months, with a very significant difference among the three subgroups (P < 0.001). The overall survival times of EZH2(-) p53(-), EZH2(+) or p53(+), and EZH(2+) p53(+) cases were (72.9 ± 1.1), (68.6 ± 1.8), and (57.4 ± 3.4) months, respectively, with a significant difference among the three subgroups (P < 0.001). The multivariate analysis showed that EZH2 expression, lymph node metastasis and tumor staging were independent prognostic factors.

CONCLUSIONSBoth EZH2 and p53 proteins may play important roles in the occurrence and development of cervical squamous cell carcinoma. There is a close relationship between the expression of both EZH2 and p53 proteins and the prognosis of SCC patients.