Cytoplasmic Pin1 expression is correlated with poor prognosis in colorectal cancer

The aim of this study was to determine the clinicopathological significance and prognostic role of Pin1 expression and subcellular localization in colorectal cancer (CRC).

The Pin1 expression, as well as cytoplasmic and nuclear localization, was investigated using immunohistochemistry in 265 human CRC tissues. The impact of subcellular localization of Pin1 on clinicopathological significance and prognosis in CRC was evaluated.

Pin1 was expressed in 164 of 265 CRCs (61.9%). Pin1 expression was not significantly correlated with any clinicopathological parameters. However, Pin1 expression was significantly correlated with worse overall and recurrence-free survivals (P =  0.002 and P =  0.001, respectively). CRCs with only nuclear Pin1 expression showed no difference in survival compared to CRCs with no Pin1 expression. Over half (51.7%, 137/265) of the CRCs had any cytoplasmic Pin1 expression, and 26.8% (71/265) had both cytoplasmic and nuclear expression. Cytoplasmic Pin1 expression was more frequent than only nuclear or no Pin1 expression in cases with vascular invasion and distant metastasis. Cytoplasmic Pin1 expression was significantly correlated with worse overall and recurrence-free survivals (P <  0.001 and P <  0.001, respectively).

Taken together, our results indicated different prognostic roles of subcellular Pin1expression in CRC. Cytoplasmic expression of Pin1, with or without nuclear expression, is an important factor in predicting aggressive tumor behavior and worse prognosis.