Abstract
The implication of HLJ1, a member of the heat shock protein-40 chaperone family, in colorectal carcinoma (CRC) remains unclear. The aim of this study was to determine the dynamic changes of HLJ1 in CRC both in vitro and in vivo, and the relationship between its level and the survival rate of CRC patients. Both real-time RT-PCR and Western blot were used to detect the expression of HLJ1 in CRC cells, while the distribution of HLJ1 in CRC and its adjacent normal mucosa tissues from CRC patients was determined with immunohistochemistry. Moreover, MTT and in vitro invasive assays were performed to determine the effect of HLJ1 overexpression on cell proliferation and invasion of CRC cells. The results indicated that in highly metastatic CRC cells, the HLJ1 expression was lower than that in lowly metastatic ones, and that the overexpression of HLJ1 significantly inhibited CRC cell proliferation and invasion in vitro. Interestingly, the HLJ1 expression was significantly down-regulated in CRC or lymphatic metastatic tissues from patient, compared to that in the normal mucosa (P<0.05), and the HLJ1 expression was correlated strongly with lymph metastasis, Dukes' stage, and remote metastasis (P<0.05). Most surprisingly, patients with a higher HLJ1 level had a better overall survival rate, compared to that in patients with lower HLJ1 level (P<0.05). Based on all these findings, we conclude that HLJ1 is a strong tumor suppressor for CRC, and thus the down-regulation of the HLJ1 expression may be used as a biomarker to predict clinical outcome of patients with CRC.