Epigenetic silencing of maspin gene expression in human breast cancers

Significance of Maspin, uPA and MMP-7 expression in human gastric carcinoma

AIM: To investigate the expression of Maspin, urokinase-type plasrninogen activator (uPA) uPA and Matrix metalloproteinase-7 (MMP-7) and their roles in the tumorigenesis and progre-ssion of gastric cancer.

METHODS: Immunohistochemistry SP method was used to detect the expression of Maspin, uPA and MMP-7 in tissues from gastric adenocarcinoma (n = 30), signet-ring cell carcinoma (n = 30), and normal gastric mucosa (n = 20).

RESULTS: The positive rates of Maspin, uPA and MMP-7 were 50%, 70% and 80%, respectively, in gastric adenocarcinoma, and they were 46.7%, 76.7% and 90%, respectively, in signet-ring cell carcinoma. However, the positive rates of Maspin, uPA, and MMP-7 were 90%, 35%, and 30%, respectively, in normal gastric mucosa. Maspin, uPA, and MMP-7 expression were significantly different between tissues from carcinoma and normal mucosa (P < 0.05 or P < 0.01). Maspin expression was significantly related to the depth of invasion and lymph node metastasis, but not to tumor size and TNM staging. The expression of uPA and MMP-7 were markedly related to the depth of invasion, lymph node metastasis and TNM staging, but not to tumor size. Maspin expression had a negative correlation with uPA and MMP-7 (P = 0.012, r = -0.322; P = 0.008, r = -0.341), while uPA expression had a positive correlation with MMP-7 (P = 0.034, r = 0.274).

CONCLUSION: Down-regulated expression of Maspin and up-regulated expression of uPA and MMP-7 play important roles in the invasion and metastasis of gastric carcinoma. They may serve as effective markers of reflecting the biopathological behaviors of gastric carcinoma.

Clinicopathological significance of maspin and Kail expressions in carcinogenesis and progression of gastric cancer

AIM: To investigate the expressions of maspin and Kai1 in gastric cancer and to explore their roles in tumorigenesis and progression of gastric cancer.

METHODS: Normal gastric mucosa (n = 182), gastric dysplasia (n = 69), and gastric cancer (n = 113) were detected for maspin and Kai1 expressions by immunohistochemical methods. The expressions were compared with clinicopathological parameters of the tumor. Relationship between maspin and Kai1 expressions was analyzed as well.

RESULTS: The positive rates of maspin expression were 79.8% (145/182), 75.4% (52/69), and 50.4% (57/113) in normal gastric mucosa, gastric dysplasia, and gastric cancer, while those of Kai1 expression were 81.9% (149/182), 65.2% (49/69), and 58.4% (66/113) in corresponding tissues, respectively. The gastric normal mucosa and dysplasia more frequently expressed maspin than primary gastric cancer did, (P <0.01), while the normal mucosa showed more frequent expression of Kai1 than dysplasia and primary cancer did (P <0.01). Maspin expression significantly related to invasive depth (P = 0.003<0.01), metastasis (P = 0.027<0.05), Lauren's (P = 0.015<0.05) and histological classification (P = 0.024<0.05), but not to tumor size, Borrmann's classification, growth pattern and TNM staging (P >0.05). Kai1 expression significantly related to invasive depth (P = 0.043<0.05), metastasis (P = 0.005<0.01), growth pattern (P = 0.034<0.05), Lauren's classification (P = 0.000<0.01) and histological classification (P = 0.004<0.01), but not to tumor size, Borrmann's classification and TNM staging (P >0.05). Maspin expression was significantly consistent with Kail expression in primary gastric cancer (P = 0.008<0.05).

CONCLUSION: Down-regulated expressions of maspin and Kai1 play an important role in gastric carcinogenesis. They may have inhibitory effects on invasion and metastasis of gastric cancer. Abnormal expressions of maspin and Kai1 might be an objective indicator for pathobiological behaviors of gastric cancer.