Abstract:

[Abstract]  Objective   To investigate the relationship between phosphatidylinositol3- kinase catalytic subunitα
(PIK3CA) expression and the incidence and different pathological grade of gastric cancer, and the mechanism thereof.   Methods   The expressions of PIK3CA, serine/threonine protein kinase (pAkt) and cell proliferation associated nuclear antigen(ki-67) in gastric carcinoma and adjacent tissues and normal gastric mucosa were detected by immunohistochemical method. The relationship between expressions of PIK3CA, pAkt and ki-67and tumorigenesis was analyzed. The expressions of PIK3CA, pAkt and ki-67in different pathological conditions of gastric tissues were analyzed. The relationship between tumor pathologic classification and differentiation were analyzed too. Results  There were significantly higher expressions of PIK3CA, pAkt and ki-67in gastric cancer (P<0.05), which were the highest in the poorly differentiated gastric adenocarcinoma (P<0.05). There were a positive correlation between expressions of PIK3CA, pAkt and ki-67and different pathological levels of gastric carcinoma and adjacent tissues and normal gastric tissues (P<0.05).  Conclusion   PIK3CA may be the initiating factor of PI3K/Akt signaling pathway, which induced phosphorylation of Akt and activation PI3K/Akt signaling pathway, promoting the proliferation, invasion and metastasis of gastric adenocarcinoma.

Key words: stomach neoplasms, adenocarcinoma, 1-phosphatidylinositol 3-kinase, protein-serine-threonine kinases, ki-67antigen, immunohistochemistry, tissue microarrays