Abstract: Background and purpose: The high expression of DJ-1 is closely related to the clinicopathological characteristics in colorectal cancer. However, the more detailed molecular mechanism remains unclear. The aim of the present study was to explore the role of DJ-1 in proliferation, invasion and metastasis of colorectal cancer and its possible molecular mechanism. Methods: The expression of DJ-1 was determined by Western blot, real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR) and immunohistochemistry in 34 colorectal cancer tissues compared to the corresponding normal tissues. The biological functions of DJ-1 in cell proliferation, invasion and migration were measured by EDU, colony-forming assay, transwell and wound healing assays. In addition, Western blot and RTFQ-PCR were used to analyze the relationship between DJ-1 and cyclin D1/p53-MDM2-AKT signaling pathway. Results: The results of Western blot, RTFQ-PCR and immunohistochemistry showed that DJ-1 was highly expressed in 34 cases of colorectal cancer compared to the corresponding normal tissues (P<0.01). Functional analyses revealed that overexpression of DJ-1 promoted colorectal cancer cell proliferation and migration in vitro. Furthermore, we found overexpression of DJ-1 inhibited the expression of p53 and positively regulated cyclin D1 to promote the progression of colorectal cancer detected by Western blot and RTFQ-PCR. Conclusion: This study indicates that DJ-1 promotes cell proliferation, migration and invasion in colorectal cancer via cyclin D1/p53-MDM2-AKT signaling pathway.

Key words: Colorectal cancer, DJ-1, Cyclin D1, p53, Molecular mechanism