The roles of maspin expression in gastric cancer: a meta- and bioinformatics analysis

Maspin is a mammary serine protease inhibitor that is encoded by human SERPINB5 gene, and inhibits invasion and metastasis of cancer cells as a tumor suppressor. We performed a systematic meta- and bioinformatics analysis through multiple online databases up to Feb 10, 2017. We found down-regulated maspin expression in gastric cancer, compared with normal mucosa and dysplasia (p < 0.05). Maspin expression was negatively correlated with depth of invasion, TNM staging and dedifferentiation of gastric cancer (p < 0.05). Nuclear maspin expression was higher in intestinal- than diffuse-type carcinoma (p < 0.05). An inverse association between maspin expression and unfavorable overall survival was found in patients with gastric cancer (p < 0.005). According to bioinformatics databases, SERPINB5 mRNA expression was higher in gastric cancer than normal tissues (p < 0.05), and negatively correlated with depth of invasion, TNM staging and dedifferentiation of gastric cancer (p < 0.05). According to KM plotter, we found that a higher SERPINB5 expression was positively correlated with overall and progression-free survival rates of all cancer patients, even stratified by aggressive parameters (p < 0.05). These findings indicated that maspin expression might be employed as a potential marker to indicate gastric carcinogenesis, subsequent progression, and even prognosis.