Prognostic values of the miR-17-92 cluster and its paralogs in colon cancer.

BACKGROUND

MicroRNAs have been shown to offer great potential in both the diagnosis and prognosis of cancer. Despite the well-established role of the miR-17-92 in cancer formation and progression, the contribution of each individual miRNA remains to be characterized. Thus, we investigated whether deregulation of the miR-17-92 associated with colon cancer prognosis.

METHODS

Expression levels of the miR-17-92 cluster and its paralogs were determined in 48 colon tumor and 48 paired normal tissues by real-time qRT-PCR. Associations with miRNA expression, age, sex, TNM staging, and survival prognosis were evaluated.

RESULTS

MiR-17-92 cluster and its paralogs were significantly overexpressed in colon tumor. No significant associations were found between the deregulation of certain miRNAs and the clinical and pathologic characteristics observed in patients. Kaplan-Meier curves demonstrated significantly reduced overall survival in patients expressing high levels of miR-17. In multivariate Cox models, miR-17 overexpression (HR 2.67; P = 0.007) and TNM staging (HR 8.87; P = 0.002) were significantly associated with a risk of death.

CONCLUSIONS

The miR-17-92 cluster and its paralogs were significantly elevated in patients with colon cancer, and heightened expression of miR-17 was associated with poor survival. Moreover, miR-17 and TNM staging were both identified as significant, but independent, prognostic biomarkers in colon cancer.