Expression of nm23 Protein in Human Gastric Carcinoma: correlation between nm23 expression with the development and metastasis of gastric carcinoma

Sohn, Jin Hee; Park, Hye Rym; Park, Young Oui

Abstract

Gene expression of nm23 has been investigated in many kinds of tumors, including breast cancers, colon cancers, hepatocellular carcinomas, papillary carcinomas of the thyroid and malignant melanomas since the nm23 was dislovered by Dr. Steeg as a tumor metastatic suppressor gene. Reduced expression of nm23 gene implicated in high metastatic potential in a variety of malignancies. However, there have been only a few reports on genetic alteration and expression of nm23 in human gastric carcinomas even though gastric carcinoma is a leading malignancy in Korea. In this study, we examined the expression of nm23 protein by immunohistochemistry in advanced and early gastric carcinomas, adenomas, matching normal mucosa to elucidate the role of nm23 in the development, progression and metastasis of human gastric carcinomas. The results are as follows; 1) Nm23 was expressed in 39 cases(69.6%) of 56 advanced gastric carcinomas. Among them, strong positive cases(grade 3) were 26(46.4%) and weak positive cases(grade 2) were 13(23.2%). 2) Nm23 expression was significantly different (P<0.05) depending on the site of the neoplasm. Antral carcinomas showed grade3 positivity in the 22/37 cases(60%), but carcinomas of the body showed negative (grade 1) result in about half(42.1%). 3) Nm23 expression was more intense in the neoplasm than normal mucosa.(67.9%) 4) Nm23 expression was not significantly related to the lymph node metastasis, invasion of lymphatics or veins and depth of invasion. 5) In the well differentiated carcinomas, grade3 were more common(64.0%). But in cases of signet ring cell carcinoma, many cases were negative(50.0%). 6) Nm23 expression rate and intensity was significantly increased from the normal mucosa to the gastric adenomas, early gastric carcinomas and advanced gastric carcinomas.