Expression of DJ-1 in Cancer Cells: Its Correlation with Clinical Significance.

Upregulation of DJ-1 mRNA is commonly observed in various human cancers such as ductal carcinoma of the breast, non-small cell carcinoma of the lung, pancreatic duct adenocarcinoma, urinary transitional cell carcinoma, and gynecologic carcinoma. At the protein level, intensity and intracellular localization of DJ-1 expression is varied, and the DJ-1 protein regulates cancer progression, clinical aggressiveness, differentiation, cancer cell morphology, and drug sensitivity. Thus, DJ-1 plays a critical role in cancer. Although DJ-1 has an important role within cancer cells, cancer cells secrete DJ-1 outside the cells. DJ-1 may serve as a tumor marker that can be detected from an early stage in the blood, secretory fluids, ascites, or pleural effusion.