SATB1 Protein Is Associated with a More Aggressive Phenotype of Sporadic Colorectal Cancer

Abstract

Objective: SATB1 is a genome organizer known for its role in T-cell development. With its cage-like, nuclear architecture regulates a number of genes through epigenetic modifications. Ectopic expression of SATB1 has been shown to enhance aggressive behaviour of cancer. Here, we investigated whether this putative function can also be detected in sporadic colorectal cancer. Material and Methods: SATB1 protein expression in 107 cancer samples was screened using immunohistochemistry on tissue microarrays. These stainings were evaluated with respect to clinico-pathological parameters and patient outcome. In functional assays on cell lines, association of SATB1 with tumour cell behaviour was investigated. Results: Nuclear expression of SATB1 was seen in 17.8% of the cancers. A significantly poorer disease-free survival was seen in patients positive for SATB1 expression (Log-rank test, p = 0.003). Cox regression analysis showed that SATB1 expression (p = 0.009, RR = 3.6, 95% CI = 1.4 to 9.4) was an independent predictor of disease relapse. Knockdown and ectopic expression of SATB1 in colorectal cancer cell lines lead to a corresponding decrease and increase in the migratory and invasive capacity of the respective cells. Conclusions: In colorectal cancer, nuclear expression of SATB1 correlates with a more aggressive disease. This reflects in the accompanying increased risk of disease relapse.