The Expression Of P27 And Cdk4 Protein In Endometrial Carcinoma

Objective To investigate the expressions of p27 and cdk4 proteins in endometrial carcinoma and study the relationship between them and their relationships with clinicopathlogical features so as to address the roles of these two cell-cycle proteins in the development of this malignant tumor.Methods A total of 42 endometrial carcinoma tissue blocks were obtained and stained via immunohistochemical technique with monoclonal antibody against p27 and polyclonal antibody against cdk4 respectively, another 21 hyperplasia endometrium and 16 normal endometrium tissue blocks were used as control group. Ten high-power fields were evaluated per slide with total 1000 glandular epithelial cells for p27 or cdk4 stain. More than 50% of the nuclei stained were defined as nuclear high expression and others as low expression. Cytoplasmic stain was defined according both to the proportion and the intensity of P27 or Cdk4 cytoplasmic expression. The specimens were evaluated for relationship between the two proteins and associations with age, stage, grade, histology, depth of invasion, lymph node metastasis and distant metastasis. Chi-square test, H test and Spesrman correlation analysis were used to assess the data and to generate P values, P<0.05 is valued as a significant mark.Results The high nuclear expression rate of p27 protein inendometrial carcinoma was 21.4% and that was significantly lower than 51.4% in cortrol group. The high nuclear expression rate of Cdk4 protein in endometrial carcinoma was 76.2% and that was significantly higher than 29.7% in cortrol group. There was no significant difference between normal endometrium and hyperplasia endometrium. The high nuclear expression rates of p27 in simple hyperplasia endometrium and complex hyperplasia endometrium were 57.1% and 60.0%, but in atypical hyperplasia, the rate is 22.2%, which is obviously lower than that of normal endometrium. The high nuclear expression of p27 was observed only in 3.7% of moderately and poorly differentiated tumor cells and that was significantly lower than 40.0% in highly differentiated tumor cells, however the high nuclear expression rate of Cdk4 was observed in 86.7% of the poorly and moderately differentiated tumor cells and that was significantly higher than that in highly differentiated ones(53.3%). We found that p27 or cdk4 nuclear expression had no association with age, stage, grade, histology, depth of invasion, lymph node metastasis and distant metastasis. There is no correlation between the nuclear expressions of P27 and cdk4 proteins, while low nuclear expression of p27 protein combined with high nuclear expression of cdk4 protein was significantly higher in stage II -IV (92.9%) than in stage I (53.6%) cases, and higher in poorly differentiated tumor cells than highly and moderately differentiated ones, P<0.05. Cytoplasmic stains of p27 and Cdk4 proteins were also observed besides nuclear stains. The cytoplasmic stain of p27 in endometrial tumor cells (47.6%) was significantly higher than that in control group(24.3%). There were no significances between the cytoplasmic stains of Cdk4 protein incontrol group and endometrial neoplasm group, but the positive rates were 45.9% and 23.8% respectively, showing a decrease trend.Conclusion The p27 nuclear expression trends to decrease in atypical hyperplasia and the nuclear high expression rate of p27 protein significantly decreases while that of cdk4 protein significantly increases in endometrial carcinoma, indicating that decresed nuclear expression of p27 and increased nuclear expression of Cdk4 may play a role in the development of endometrial cancer. Cytoplasmic stain of p27 protein significantly increases in endometrial carcinoma while that of Cdk4 trends to decrease, showing that the loss of nuclear localization of P27 and cdk4 proteins may relate to the inactivity of these two nuclear proteins. Low nuclear expression of p27 or high nuclear expression of cdk4 has a relationship with cell differentiation. The combination of these two conditions has relationships b...