ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of X-linked inhibitor of apoptosis protein (XIAP) in colorectal cancer tissues and investigate its correlation with the clinicopathological factors of the malignancy.</p><p><b>METHODS</b>Immunohistochemistry and RT-PCR was employed to detect the expression of XIAP in 87 colorectal cancer tissues.</p><p><b>RESULTS</b>XIAP mRNA expression was detected in 64.4% (56/87) of the colorectal cancer tissues, 49.4% (43/87) of the adjacent tissues, and in 11.4% (10/87) of the normal tissues, respectively. The cancer tissues showed significant greater positivity rate and higher expression level of XIAP mRNA than the adjacent and normal tissues. Immunohistochemistry also identified a significantly greater positivity rate for XIAP [70.1% (61/87)] in the colorectal cancer tissues. The pathological grade of the tumors was associated with the expression level of XIAP, whereas this association was not established between XIAP expression and the clinical stages, tumor position or lymph node metastasis.</p><p><b>CONCLUSION</b>XIAP may play an important role in the development of colorectal cancer, which might serve as a potentially useful tumor marker.</p>