Published in:
Open Access
01-12-2010 | Research article
Constitutive activation of glycogen synthase kinase-3β correlates with better prognosis and cyclin-dependent kinase inhibitors in human gastric cancer
Authors:
Yu Jin Cho, Ji Hun Kim, Jiyeon Yoon, Sung Jin Cho, Young San Ko, Jong-Wan Park, Hye Seung Lee, Hee Eun Lee, Woo Ho Kim, Byung Lan Lee
Published in:
BMC Gastroenterology
|
Issue 1/2010
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Abstract
Background
Aberrant regulation of glycogen synthase kinase-3β (GSK-3β) has been implicated in several human cancers; however, it has not been reported in the gastric cancer tissues to date. The present study was performed to determine the expression status of active form of GSK-3β phosphorylated at Tyr216 (pGSK-3β) and its relationship with other tumor-associated proteins in human gastric cancers.
Methods
Immunohistochemistry was performed on tissue array slides containing 281 human gastric carcinoma specimens. In addition, gastric cancer cells were cultured and treated with a GSK-3β inhibitor lithium chloride (LiCl) for immunoblot analysis.
Results
We found that pGSK-3β was expressed in 129 (46%) of 281 cases examined, and was higher in the early-stages of pathologic tumor-node-metastasis (P < 0.001). The expression of pGSK-3β inversely correlated with lymphatic invasion (P < 0.001) and lymph node metastasis (P < 0.001) and correlated with a longer patient survival (P < 0.001). In addition, pGSK-3β expression positively correlated with that of p16, p21, p27, p53, APC, PTEN, MGMT, SMAD4, or KAI1 (P < 0.05), but not with that of cyclin D1. This was confirmed by immunoblot analysis using SNU-668 gastric cancer cells treated with LiCl.
Conclusions
GSK-3β activation was frequently observed in early-stage gastric carcinoma and was significantly correlated with better prognosis. Thus, these findings suggest that GSK-3β activation is a useful prognostic marker for the early-stage gastric cancer.