Colorectal cancer progression correlates with upregulation of S100A11 expression in tumor tissues

Early detection and treatment of human colorectal cancers remain a challenge. Identification of new potential markers may help in the diagnosis of colorectal cancer. By comparative two-dimensional gel electrophoresis using extracts from colorectal tumor and adjacent normal tissues, we identified a calcium-binding protein, S100A11, which was highly expressed in colorectal cancer compared with adjacent normal tissues. We expanded our study in 89 clinical colorectal tumor samples to validate this finding and correlates S100A11 expression in human colorectal cancer tissues with various stages of the tumor by Western blotting and immunohistochemical staining. We identified a calcium-binding protein, S100A11, which was highly expressed in colorectal cancer compared with adjacent normal tissues. S100A protein was expressed predominantly in the cytoplasm of normal tissue; however, it was expressed in both the nuclei and cytoplasm of colorectal cancer. S100A11 level in colorectal cancer tissue was increased following stage progression of the disease. These findings suggest S100A11 could be helpful in the pathological study of colorectal cancer, especially for the classification of different stages in colorectal cancer.