Maspin expression and its clinicopathological significance in tumorigenesis and progression of gastric cancer

AIM:To investigate maspin expression in tumorigenesis and progression of gastric cancer and to explore its relevant molecular mechanisms.METHODS:Formalin-fixed and paraffin-embedded tissues from normal mucosa (n=182), dysplasia (n=69), cancer (n=l13) of the stomach were studied for maspin expression by immunohistochemistry. Microvessel density (MVD) in gastric cancer was labeled using anti-CD34 antibody. Maspin expression was compared with clinical parameters and MVD of tumors. Caspase-3 expression was also detected in gastric carcinoma by immunohistochemistry. The relationship between Caspase-3 and maspin expression was concerned 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 mucosa, dysplasia and cancer of the stomach,respectively.Cancer less frequently expressed maspin than normal mucosa and dysplasia (P<0.05).Maspin expression showed a significantly negative association with invasive depth, metastasis, Lauren's and Nakamura's classification (P<0.05),but not with tumor size, Borrmann's classification,growth pattern or TNIVl staging (P>0.05). The positive rate of Caspase-3 was significantly lower in gastric cancer than in normal gastric mucosa (P<0.05,32.7% vs 50.4%). It was noteworthy that maspin expression was negatively correlated with MVD, but positively correlated with expression of Caspase-3 in gastric cancer (P<0.05).CONCLUSION:Down-regulated maspin expression is a late molecular event in gastric carcinogenesis. Reduced expression of maspin contributes to progression of gastric cancer probably by inhibiting cell adhesion, enhandng cell mobility,decreasing cell apoptosis and facilitating angiogenesis.Additionally altered expression of maspin underlies the molecular mechanism of differentiation of gastric cancer and supports the different histogenetic pathways of intestinal and diffuse gastric cancers. Maspin expression can be considered as an effective and objective marker to reveal biological behaviors of gastric cancer.

EXPRESSION OF MASPIN AND KAI1 AND THEIR CLINICOPATHOLOGICAL SIGNIFICANCE IN CARCINOGENESIS AND PROGRESSION OF GASTRIC CANCER

To investigate the roles of maspin and kai1 expression in tumorigenesis and progression of gastric cancer. Methods Maspin and kai1 expressions were detected in normal gastric mucosa (n = 182), gastric dysplasia (n = 69), and gastric cancer (n = 113) by immunohisto-chemistry. Their expressions were compared with clinicopathological parameters of tumors. Relationship between maspin and kai1 expression was also concerned in gastric cancer. 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. Gastric cancer less frequently expressed maspin than the normal gastric mucosa and gastric dysplasia (P < 0.05), while dysplasia and cancer showed less frequent expression of kai1 than normal mucosa (P < 0.05). Maspin expression showed negative association with invasive depth, metastasis, Lauren’s and histological classifications (P < 0.05), but not with tumor size, Borrmann’s classification, growth pattern or TNM staging (P > 0.05). Kai1 expression was negatively correlated with invasive depth, metastasis, growth pattern, Lauren’s and histo-logical classifications (P < 0.05), but not with tumor size, Borrmann’s classification or TNM staging (P > 0.05). Maspin and kai1 were collaboratively expressed in gastric cancer (P < 0.05). Conclusions Down-regulated expressions of maspin and kai1 play an important role in gastric carcinogenesis. Abnormal expression of maspin and kai1 might have inhibitory effects on invasion and metastasis of gastric cancer and act as an effe-ctive and objective marker to indicate the pathobiological behaviors of gastric cancer.

Expression And Clinical Significance of Glucose Regulated Proteins GRP78 And GRP94 in Human Colon Cancer

Objective： To investigate the expression of glucose regulated proteins GRP78 and GRP94 in human colon cancer. Methods： Tissues of resected primary colon cancer, colon adenoma and normal tissue were investigated. Protein expression was detected with immunohistochemical staining, mRNA expression levels of GRP78 and GRP94 were determined by semiquantitative reverse transcriptase polymerase chain reaction （RT-PCR） after mRNA extraction. Results： The expression of GRP94 and GRP78 was significantly higher in colon cancer when compared to those in colon adenoma and normal tissue （P〈0.01）. GRP94 mRNA and protein expression was found to be in close relationship with the grade of differentiation, Dukes stages, lymph node involvement and remote metastasis in colon cancer （P〈0.01）, but no relationship with gender and age （P〉0.05）. GRP78 mRNA and protein expression increased with cancer progression along the normal tissue-adenoma-cancer sequence, but showed no association with grade of differentiation, Dukes stages, lymph node involvement, remote metastasis, gender and age （P〉0.05）. The mRNA expression of GRP78 and GRP94 was consistent with the proteins （P〈0.01）, but there is no correlation between overexpression of GRP78 and GRP94 （P〉0.05）, and the patients with both strong GRP78 and GRP94 protein expression did not show advanced tumor stages （P〉0.05）. Conclusion： Overexpression of GRP78 and GRP94 was found in colon cancer. Overexpression of GRP94 was closely related to cellular differentiation, Dukes stages, invasion and metastasis.