DJ­1 is a new prognostic marker and predicts chemotherapy efficacy in colorectal cancer.

Protein/nucleic acid deglycase DJ­1 (DJ­1) is a 20­kDa conserved protein, which belongs to the DJ­1/ThiJ/Pfp â…  protein superfamily. Immunohistochemistry was performed to investigate the expression of DJ­1 in a colorectal cancer (CRC) tissue microarray containing tumor and corresponding adjacent normal tissues. In the present study, DJ­1 expression was significantly upregulated in CRC cells and tissues, compared with that in normal colon cells and adjacent normal tissues, respectively. In addition, patients with high DJ­1 expression levels had a worse overall survival (OS) compared with patients with low expression levels. Multivariate Cox regression analysis revealed that high DJ­1 expression levels was an independent prognostic factor for patients with CRC. Moreover, DJ­1 was able to regulate the PI3K/Akt/p27/cyclin E and PI3K/Akt/mTOR signaling pathways to promote CRC cell growth and metastasis in vitro and in vivo. In addition, DJ­1 regulated the NF­κB/Snail signaling pathway to induce CRC cell epithelial­mesenchymal transition to promote migration and invasion. Notably, patients receiving LFP treatment (oxaliplatin, 5­FU and tetrahydrofolate) had an increased OS compared with patients who underwent only surgery and low DJ­1 expression levels. The findings from the present study suggest that DJ­1 may serve as a promising prognostic marker and predicts chemotherapy efficacy in patients with CRC.