Expression and significance of IGF-2, PCNA, MMP-7, and α-actin in gastric carcinoma with Lauren classification.

BACKGROUND/AIMS: By detecting the expression and distribution of insulin-like growth factor-2, proliferating cell nuclear antigen, and matrix metalloproteinase-7 in cancer cells and the expression of α-actin in interstitial myofibroblasts, we studied their differences and their relationship in intestinal type and diffuse type gastric cancer with Lauren classification.

MATERIALS AND METHODS

Clinical and pathological data of 50 patients with gastric adenocarcinoma who underwent primary surgical resection between 2003 and 2008 in Qianfoshan Hospital were collected. The cancer was classified as intestinal or diffuse type with Lauren classification. Immunohistochemical technique was used to detect the protein expression of insulin-like growth factor-2, proliferating cell nuclear antigen, matrix metalloproteinase-7, and α-actin in both gastric cancer tissue and normal gastric mucosa.

RESULTS

The expression of insulin-like growth factor-2, proliferating cell nuclear antigen, matrix metalloproteinase-7, and α-actin in the gastric tissue was significantly higher than in the normal gastric mucosa. Insulin-like growth factor-2 was mainly expressed in the nucleus in diffuse gastric cancer and in the cytoplasm in intestinal type. The expression of insulin-like growth factor-2 in the nucleus was correlated with depth of tumor invasion, lymph node metastasis and staging. Proliferating cell nuclear antigen and matrix metalloproteinase-7 showed higher expression in diffuse than in intestinal type gastric cancer. The overexpression of proliferating cell nuclear antigen was relevant to lymph node metastasis in gastric cancer. The overexpression of matrix metalloproteinase-7 was relevant to invasion, lymph node metastasis, distant metastasis, and staging in gastric cancer. There was no significant difference in α-actin expression between the intestinal type and diffuse type gastric cancer. The overexpression of α-actin was relevant to cancer invasion and lymph node metastasis.

CONCLUSIONS

The expression patterns of insulin-like growth factor-2 and the expression intensity of proliferating cell nuclear antigen and matrix metalloproteinase-7 were significantly different between diffuse type and intestinal type gastric cancer cells, but the expression pattern and intensity of the interstitial myofibroblast marker showed no significant difference. The clinical pathology distinction between intestinal type and diffuse type gastric cancer may be due mainly to the change in the genetic structure and the phenotype of epithelial cells, and interstitial myofibroblasts and cancer cells jointly promote the invasion and metastasis of gastric cancer.