Overexpression of clusterin correlates with tumor progression, metastasis in gastric cancer: a study on tissue microarrays.

Clusterin (CLU) is expressed in a wide variety of human tissues and fluids. Overexpression of cytoplasmic clusterin (sCLU) has been implicated in cancer development and progression. The aim of the present study is to evaluate the association of sCLU overexpression with clinicopathological features of human gastric carcinomas (GC).We constructed a gastric cancer tissue microarray containing 173 primary gastric carcinomas and 70 paired non-neoplastic mucosa specimens. The expression of sCLU was studied by immunohistochemistry. The correlations between sCLU expression and clinicopathological features, p53 abnormality, as well as Ki67 activation were analyzed. Overexpressions of sCLU was detected in 28.5% (n=165) of primary GCs by immunohistochemical staining, but not in non-neoplastic mucosa. Clinical association study found that overexpression of sCLU was significantly correlated with lymph-node metastasis (p < 0.001), tumor invasion (p < 0.001) and TNM stage (p < 0.001). In Kaplan-Meier survival analysis, overexpression of sCLU was significantly correlated with unfavorable survival in advanced GCs (p < 0.03). Furthermore, the association of sCLU with abnormal expression of p53 was ascertained. These results suggested that overexpression of sCLU was involved in the progression of GC and it's oncogenic function might be associated with p53 abnormality. Overexpression of sCLU seems to be related with patient's shorter survival in late stage GC.