A Comparative Study Of E-Cadherin MRNA Expression Between Primary Tumors And Metastatic Foci In Gastric Cancer

ObjectiveTo evaluate the expressive level of E-Cadherin (E-CD) mRNA in primary tumors, metastatic lymph nodes and peritoneal lavage fluid from patients with gastric cancer in relation to biologic behavior.MethodsThe level of E - CD mRNA expression was examined in primary tumors, corresponding tumor free tissues, metastatic lymph nodes and peritoneal lavage fluid by reverse transcription polymerase chain reaction ( RT - PCR). Tissue specimens were obtained by surgical resection from 35 patients with gastric cancer, among which tumor tissues and metastatic lymph nodes were confirmed by pathological examination , part of peritoneal lavage fluid was detected free cancer cells by PLC. Specimens were isolated RNA by TRIZOL reagent, turned RNA into cDNA by reverse transcription, detected the expression of E - CD by PCR and electrophoresis, analyzed the electrophoretic images by Gel work - ID software, lastly, calculated the values representing the expressive level of mRNA.Results1. E - CD mRNA expression in primary tumora: The level of E -CD mRNA in primary tumors decreased significantly than that in tumor free tissues and was closely related to malignant biologic behavior of tumor.2. The difference of E - CD mRNA expressive level between primary tumors and metastatic lymph nodes: The difference between differentiated and undifferentiated metastatic lymph nodes was not significant. The total expressive level in metastatic lymph nodes was significantly higher than that in primary tumors. The differential value between metastatic lymph node and corresponding primary tumor was related significantly to malignant biologic behavior and extent of metastasis of gastric cancer.3. E - CD mRNA expression in peritoneal lavage fluid; All the 35 specimens of peritoneal lavage fluid expressed E - CD mRNA. The expressive level was closely related to serosal type and the results of PLC.Conclusion1. The expression of E - CD mRNA in primary tumors decreased and correlated positively to the malignant biologic behavior in gastric cancer.2. In metastatic lymph nodes, there exists E - CD mRNA re -expression. The ability of re - expression correlated negatively to the malignant biologic behavior in gastric cancer.3. In peritoneal metastasis, there also exists E - CD mRNA re -expression. But the determination of E - CD mRNA in peritoneal lav-age fluid is not specific for PLC inspection in gastric cancer.