Introduction: Over 20% of colorectal cancer (CRC) patients seek medical attention for the first time when they are in the advanced stages of CRC. Thus, early and reliable detection of CRC is critical to early diagnosis of CRC. Protein disulfide isomerase A3 precursor (PDIA3) has been implicated in various types of cancers. However, little is known about PDIA3 in CRC. 
Methods: In this study, we screened PDIA3 expression in CRC tissues and cell lines. Small interfering RNA (siRNA) was introduced into SW480 cells to knockdown PDIA3 expression. The effect of PDIA3 in cell growth was evaluated.
Results: Significant upregulation of PDIA3 expression was found in CRC tissues as compared with adjacent non-cancer tissues, and was found in established CRC cell lines (SW480, HCT116, CACO2, NCM460 and HT-29). In SW480 cells, knockdown of PDIA3 expression with siRNA resulted in subcellular morphological change, reduced cell proliferation and increased apoptosis.
Conclusion: PDIA3 inhibition could suppress CRC, likely through inducing apoptosis. PDIA3 could be a potential therapeutic target for CRC.
Keywords: PDIA3, colorectal cancer, proteomics, siRNA, apoptosis