Downregulation of miR-186 is associated with metastatic recurrence of gastrointestinal stromal tumors

Abstract

Although dysregulation of microRNAs (miRNAs/miRs) is a common feature of human malignancies, its involvement in gastrointestinal stromal tumors (GISTs) is not fully understood. The present study aimed to identify the miRNAs that perform a role in GIST metastasis. miRNA expression profiles from a series of 32 primary GISTs were analyzed using microarrays, and miR-186 was observed to be downregulated in tumors exhibiting metastatic recurrence. Reverse transcription-quantitative polymerase chain reaction analysis of an independent cohort of 100 primary GISTs revealed that low miR-186 expression is associated with metastatic recurrence and a poor prognosis. Inhibition of miR-186 in GIST-T1 cells promoted cell migration. Gene expression microarray analysis demonstrated that miR-186 inhibition upregulated a set of genes implicated in cancer metastasis, including insulin-like growth factor-binding protein 3, AKT serine/threonine kinase 2, hepatocyte growth factor receptor, CXC chemokine receptor 4 and epidermal growth factor-containing fibulin-like extracellular matrix protein 1. These results suggest that the downregulation of miR-186 is involved in the metastatic recurrence of GISTs, and that miR-186 levels could potentially be a predictive biomarker for clinical outcome.

Keywords: gastrointestinal stromal tumor; metastasis; microRNA; recurrence.

Figure 1.

Low miR-186 expression is associated with metastatic recurrence of GISTs. (A) Volcano plot of miRNA microarray data used to identify differentially expressed miRNAs between GISTs with metastatic recurrence (n=5) and those without recurrence (n=27). miR-186 expression is highlighted by a circle. (B) Summary of reverse transcription-quantitative polymerase chain reaction analysis of miR-186 in primary GISTs with (n=15) and without metastatic recurrence (n=85). miR, microRNA; GIST, gastrointestinal stromal tumor.

Figure 2.

Low expression of miR-186 is associated with poor prognosis of patients with GIST. Kaplan-Meier curves demonstrate the effects of miR-186 expression (high, miR-186/U6 ≥0.143; low, miR-186/U6 <0.143) on survival among patients with GIST. *P<0.05. miR, microRNA; GIST, gastrointestinal stromal tumor.

Figure 3.

Inhibition of miR-186 did not affect GIST-T1 cellular proliferation. Growth curves are presented for GIST-T1 cells transfected with a miR-186 inhibitor or a negative control generated using cell viability assays. miR, microRNA; GIST, gastrointestinal stromal tumor.

Figure 4.

miR-186 inhibition promoted migration of GIST-T1 cells. (A) Representative results from wound healing assays using GIST-T1 cells transfected with a miR-186 inhibitor or a negative control. The wound was made 24 h after transfection, and photographs were captured at the indicated time points. (B) Summary of the wound healing assay results obtained from three independent experiments. Error bar represent standard deviations. *P<0.05. miR, microRNA; GIST, gastrointestinal stromal tumor.

Figure 5.

Inhibition of miR-186 affects gene expression profiles in GIST-T1 cells. (A) Heat map showing the changes in gene expression subsequent to miR-186 inhibition in GIST-T1 cells. Genes upregulated or downregulated by the miR-186 inhibitor (>1.5-fold) were selected, and hierarchical clustering was subsequently performed. (B) Heat map of metastasis-associated genes upregulated by miR-186 inhibition in GIST-T1 cells. miR, microRNA; GIST, gastrointestinal stromal tumor; Met, hepatocyte growth factor receptor; EFEMP1, epidermal growth factor-containing fibulin-like extracellular matrix protein 1; AKT2, AKT serine/threonine kinase 2; CXCR4, CXC chemokine receptor 4; IGFBP3, insulin-like growth factor-binding protein 3.