Peroxiredoxins (Prdxs) are a family of
antioxidant enzymes that are also known as scavengers of
peroxide in mammalian cells. Some reports have shown that the overexpression of Prdx1, which is one of the
peroxiredoxins that is a ubiquitously expressed
protein, was related to a poor prognosis in several types of human
cancers. In this study, we investigated the expression levels of Prdx1 in
esophageal squamous cell carcinoma by immunohistochemistry, and the correlation between the Prdx1 expression and the clinical status was elucidated. Immunohistochemical staining was performed in 114 samples which were collected from surgical
esophageal cancer specimens. Cytoplasmic staining of Prdx1 was evaluated based on the following scoring criteria: Grade I, negative or weak staining; Grade II, moderate staining; and Grade III, strong staining. The percentage of patients with a Grade I expression of Prx1 was 20% (23 of 114), 44% had Grade II (50 of 114), and 36% had Grade III (41 of 114). The Prdx1 immunoreactivity showed an inverse significant correlation with T-category (P<0.0001),
lymph node metastasis (P=0.048), and stage (P=0.001). In addition, the patients with
tumors exhibiting a reduced Prdx1 expression had shorter overall survival (P=0.022) in comparison to the patients with
tumors which had a higher Prdx1 expression. Currently, Prdx1 has been shown to act as a
tumor suppressor. Our results provide strong evidence that the reduced Prdx1 expression is an important factor in esophageal squamous
cancer progression and could serve as a useful prognostic marker.