Objective: To study the expression of maspin protein and the correlation between maspin and P53 proteins in gastric carcinoma, so as to provide a new valid index for diagnosis of gastric carcinoma.
Methods: Western blotting, immunofluorescence test, and immunohistochemistry were conducted in 32 fresh specimens of gastric carcinoma tissue and adjacent normal tissues obtained during operation performed from January to December 2005 and 232 specimens of gastric tissues obtained during operation or fibergastroscopy, including 172 specimens of gastric carcinoma, conducted 1998 approximately 1999., to determine the protein expression of maspin and P53. The relationship between the protein expression of maspin and that of P53 was analyzed.
Results: The positive rates of maspin protein in the specimens of fresh gastric carcinoma tissues by Western blotting, immunofluorescence test and immunohistochemistry were 56.3%, 50.0%, and 43.8% respectively without significant differences among these 3 groups (all P>0.05). The positive rates of P53 protein in the specimens of the fresh gastric carcinoma tissues by Western blotting, immunofluorescence test and immunohistochemistry were 46.9%, 40.6%, and 37.5% respectively without significant differences among these 3 groups (all P>0.05). The analysis of the 232 specimens of gastric tissues obtained during operation or fibergastroscopy showed that the higher the differentiation of the gastric tissue and the lower the stage of carcinoma the higher the positive rate of maspin protein. The positive rates of maspin protein of the normal gastric mucosa, tissue with atypical hyperplasia, and tissue of gastric carcinoma were 58.3%, 52.8%, and 40.1% respectively with significant differences among these 3 groups (all P<0.05). The positive rate of maspin protein of the tissue with lymph node metastasis was 28.8%, significantly lower than that of the tissues without lymph node metastasis (64.8%, P<0.05). The positive rate of maspin protein of the patients surviving for more than 3 years was 63.5%, significantly higher than that of the patients surviving for 3 years or less (29.6%, P<0.05). Spearman rank correlation test showed a negative correlation between the protein expression of maspin and that of P53 (P<0.01).
Conclusion: The expression of maspin protein is negatively correlates with that of P53 protein. Detection of both maspin and P53 can serve as a prognostic predictor of clinical outcome in the patients with gastric carcinoma.