Peroxiredoxins in colorectal neoplasms.

Peroxiredoxins (Prxs) are novel group proteins with efficient antioxidant capacity, and some of them also have effects on cell proliferation, differentiation, apoptosis, and chemotherapy and radiotherapy resistance. Altogether six distinct Prxs expressions were investigated in histological samples of colorectal neoplasm and the distant normal tissues and investigated associatedly with parameters such as clinical stage and lymphnodes metastasis. Normal colorectal tissues were almost negative for Prxs, except Prx4 (15/32). In colorectal cancer tissues, the most prominent reactivity was observed with Prx2 in 23/32 cases, while the corresponding figures for others was 21/32 (Prx1), 18/32 (Prx3, Prx5, Prx6) and 8/32 (Prx4). Prx1 (P=0.023), Prx2 (P=0.012), and Prx5 (P=0.028) were the isoforms that showed significantly increased expression in colorectal cancer patients with stage III or lymphnodes metastasis-positive cases. There was a significant relationship between the expression of Prx1 and Prx2 (rs=0.425, P=0.015) and between Prx3 and Prx4 (rs=0.364, P=0.041). Additionally, 8 cases were studied by western analysis. Prx1, 2, 3, 5 and 6 were particularly elevated in tumors compared to nonmalignant tissue as assessed by immunohistochemistry. It appeared that some Prxs were upexpression in colorectal cancer tissues and may have some prognostic significance; the induction of Prxs could be explained by increased production of reactive oxygen species in carcinomatous tissue.