Objective: To study the expression and significance of cyclin E, cyclin D1, CDK4 and p27 protein in esophageal squamous cell cancer (ESCC) and their correlation with tumor differentiation and lymph node metastasis.
Methods: Expressions of cyclin E, cyclin D1, CDK4 and p27 protein in 65 patients with ESCC were quantitatively detected by flow cytometry.
Results: The expressions of cyclin E, cyclin D1, CDK4 in poorly-differentiated ESCC were higher than those in well-differentiated ESCC (P = 0.0275, 0.0001, 0.0174). The expression of p27 in poorly-differentiated ESCC was lower than that in well-differentiated ESCC (P = 0.0042). There was positive correlation between cyclin E and cyclin D1, cyclin D1 and CDK4, but negative correlation between cyclin D1 and p27. The expressions of all four proteins were not correlated with lymph node metastasis.
Conclusion: The expressions of cyclin E, cyclin D1, CDK4 and p27 are closely related to tumor differentiation of ESCC. An imbalance between positive and negative control of cell cycling might be critical in the carcinogenesis of esophageal squamous cell cancer.