Study On P16, Cyclin D1 And CDK4 Expression And Measurement Of Nuclear Volume In Esophageal Carcinoma

Objectives: Active search for relevant molecular biological markers of esophageal carcinoma can provide bases for elucidation of its etiological mechanism.The tumor suppressor gene p16 is a gene that plays a certain role in the cell cycle directly.Therefore my study aimed to investigate the expression of p16,Cyclin D1 and CDK4 proteins and the correlation between these proteins,as well as the role of pl6 gene in tumorigenesis and progression of esophageal carcinoma. Also my research aimed to find out the possible correlation between cancer cell mean nuclear volume and some clinicopathological characteristics in esophageal carcinoma by using a computer-assisted image analysis system as the mean nuclear volume was measured quantitatively by adopting appropriate stereological means.Materials and Methods: All of the specimens came from 45 patients with esophageal carcinoma who underwent curative esophagectomy without any adjuvant chemotherapy or radiotherapy before surgery in Jieyang Municipal People's Hospital,Guangdong Province.The expression of p16,Cyclin D1 and CDK4 proteins were evaluated immunohistochemically.The results were statistically analyzed by rank sum test and Spearman correlation test by using SPSS 10.0.(a=0.05). The measurement of mean nuclear volume of esophageal carcinoma cell was performed by adopting Feulgen Staining and the technique of computer-assisted image analysis.The results were statistically analyzed by t test by using SPSS 10.0.(a=0.05).Results: 1. p16 protein was detected in 25 out of all the 45 cases. The expression of pl6 protein did not correlate with the cancer differentiation level, the depth of invasion and lymph nodal metastasis. Cyclin D1 expression was observed in 34 out of all cases.The expression of Cyclin D1 was correlated with the depth of cancer invasion(Z=-2.026,P=0.043),while it was not associated with the differentiation level and lymph nodal metastasis.CDK4 expression was observed in 33 out of all cases. The expression of CDK4 associated with the cancer differentiation level (Z=-2.262,P=0.024),while it did not correlate with the invasion depth and lymph nodal metastasis.2. A significant inverse correlation was recognized between pl6 and Cyclin D1 expression (r_s=-0.358, P=0.016).3. The mean nuclear volume of esophageal carcinoma cell that measured through a computer-assisted image analytical system did not associate with the clinicopathological characteristics such as cancer differentiation level,depth of invasion and lymphatic metastasis.