Relationship Between Expression Of COX-2 And Cell Cycle Regulatory Proteins In Patients With Esophageal Squamous Cell Carcinoma

Objective To investigate the immunohistochemical expression of COX-2 and cell cycle regulatory protein (Ki-67, cyclin A, p27), and to find out the correlation between COX-2 and cell cycle-regulatory proteins in patients with esophageal squamous cell carcinoma (ESCC).Methods The expression of COX-2, Ki-67, cyclin A and p27 was examined by immunohistochemistry in 102 surgically obtained ESCC specimens and 28 specimens of tumor-adjacent normal squamous epithelium as controls. Scoring was performed using an intensity-proportionscoring system, The percentage of positively labelled cells (0–100%) in each section was multiplied by the intensity of labelling, graded from 0 (no labelling) to 3 (intense labelling), providing a score between 0 and 300.The average value of five fields was the final result. The Correlations between factors( COX-2, Ki-67, cyclin A and p27) and clinico-pathologic parameters was investigated by analysis of variance. the correlation between COX-2 and cell cycle-regulatory proteins in ESCC was using the Pearson rank correlation test. P value <0.05 was considered significant· Results (1)The mean sore of COX-2 in ESCC and normal squamous epithelium was 30.2 and 74.7, respectively, the expression of COX-2 was higher in ESCC than normal squamous epithelium(P<0.01).(2) The mean sore of Ki-67 in ESCC and normal squamous epithelium was 11.6 and 64.0, respectively, the expression of Ki-67 was higher in ESCC than normal squamous epithelium(P<0.01).(3) The expression of cyclin A was significantly higher in ESCC than normal squamous epithelium(,44.2 vs11.7, P<0.01).(4) The protein level of p27 was significantly lower in ESCC than in normal squamous epithelium (266.4vs 87.7, P<0.01).(5) In ESCC, COX-2 expression was correlated to T stage, the sore of T1-T2stage lower than T3-T4 stage (55.0±42.3vs83.0±66.5, t=-2.62, P<0.05),(6) Ki-67, cyclin A and p27 expression were correlated to differentiation (F=7.839, P<0.01, F=3.519, P<0.05, F=5.49, P<0.01).(7) COX-2 expression was positively correlated to Ki-67, cyclin A (r= 0.270,P<0.01,r=0.233,P<0.01),and negatively correlated to p27 expression(r=-0.311,P<0.01)in ESCC.Conclusions (1) The expression of COX-2, Ki-67 and cyclin A was significantly higher, but the p27 expression was lower in ESCC than in normal squamous epithelium (P<0.01).(2) COX-2 expression was correlated to T stage in the ESCC, COX-2 expression could reflect the invasion of ESCC cells.(3) Ki-67, cyclin A and p27 expression were correlated to differentiation, and their expression could reflect the proliferation of ESCC cells. (4) COX-2 expression was positively correlated to Ki-67, cyclin A,and negatively correlated to p27 expression in ESCC. We could reveal that high COX-2 expression was closely correlated with the proliferation of ESCC cells.