Overexpression of Pim-1 is associated with poor prognosis in patients with esophageal squamous cell carcinoma.

BACKGROUND AND OBJECTIVES

It is well known that provirus integration site for Moloney murine leukemia virus 1 (Pim-1) plays an essential role in the occurrence and development of tumors. Here, we investigated expression of Pim-1 in esophageal squamous cell carcinoma (ESCC) and assessed the correlation between Pim-1 level and prognosis of the patients with ESCC.

METHODS

Expression of Pim-1 was investigated by RT-PCR, immunohistochemistry, and in situ hybridization methods. Kaplan-Meier statistics was used to examine the relationship between levels of Pim-1 and prognosis using log-rank test.

RESULTS

The results demonstrated that ESCC tissues appeared strong expression levels of Pim-1 mRNA and protein while the normal esophageal tissues were either negative or showed only weak Pim-1 mRNA and protein levels. In addition, we found that Pim-1 expression was significantly correlated with histology grade, clinical staging, and lymph node metastasis (all P < 0.05), but not related to age and sex (all P > 0.05). Furthermore, the results of survival rates analyzed by Kaplan-Meier curve revealed that patients with high Pim-1 mRNA and protein expressions had a poorer prognosis than those with the low Pim-1 expression (P = 0.010 and 0.001, respectively).

CONCLUSION

These findings demonstrate that Pim-1 may be used as molecular marker for predicting the prognosis of patients with ESCC.