Decreased expression of miR-218 is associated with poor prognosis in patients with colorectal cancer

Abstract

The identification of biomarkers in colorectal cancer (CRC) diagnosis and therapy is important in achieving early cancer diagnosis and improving patient outcomes. The aim of this study was to examine clinical significance of miR-218 expression in sera and tissues from CRC patients. A total of 189 cases and 30 healthy subjects were included. The expression levels of miR-218, SLIT2 and SLIT3 were measured by quantitative reverse transcription PCR (qRT-PCR). The relationship between miR-218 expression and clinicopathological characteristics was investigated. The expression levels of miR-218, SLIT2 and SLIT3 in CRC tissues were decreased than those in adjacent normal tissues (all P < 0.05). miR-218 expression was significantly associated with TNM stage, lymph node metastasis (LNM) and differentiation (all P < 0.05). Patients with low miR-218 expression had shorter survival time than those with high miR-218 expression (P = 0.036). Furthermore, the expression levels of serum miR-218 in CRC patients were lower than those in controls (P = 0.005). An increased level of serum miR-218 was found 1 month after surgery (P = 0.026). In conclusion, the miR-218 may has important roles in the development and progression of CRC and be a potential diagnostic and prognostic biomarker of CRC.

Keywords: Colorectal cancer; expression; miR-218; microRNA; survival.

Figure 1

miR-218, SLIT2 and SLIT3 were downregulated in CRC. A: The expression level of miR-218 in CRC patients (n = 189). B: The expression level of miR-218 in CRC patients (n = 189) at different clinical status. C and D: The expression levels of SLIT2 and SLIT3 in CRC patients (n = 26), respectively.

Figure 2

Kaplan-Meier curves for overall survival and miR-218 expression in group of 189 CRC patients.

Figure 3

Serum miR-218 levels. A: Serum miR-218 expression in CRC patients (n = 30) and controls (n = 30). B: Changes in serum miR-218 levels before (Pre-operation) and after surgery (Post-operation).