Prognostic value of microRNA-100 in esophageal squamous cell carcinoma

MicroRNA-100 (miR-100) has been demonstrated to be implicated in tumorigenesis and tumor progression of human esophageal squamous cell carcinoma (ESCC). However, its expression patterns in ESCC are controversial and its prognostic value in this malignancy has not been fully elucidated. The aim of this study was to investigate the expression and clinical significance of miR-100 in ESCC.

Real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) was performed to detect expression levels of miR-100 in 120 self-paired specimens of ESCC and adjacent normal esophageal tissues. The associations of miR-100 expression with clinicopathologic features, locoregional progression-free survival (LPFS), distant progression-free survival (DPFS), and overall survival (OS) of patients with ESCC were statistically analyzed.

Compared with adjacent normal esophageal tissues, the expression levels of miR-100 in ESCC were significantly decreased (normal versus ESCC: 3.53 ± 1.22 versus 1.89 ± 0.38, P <0.001). Additionally, low miR-100 expression in ESCC tissues was significantly associated with the advanced clinical stage (P = 0.008), the presence of distant metastasis (P = 0.008), and the great depth of invasion (P = 0.02). Moreover, univariate analysis revealed that low miR-100 expression was associated with poor LPFS, DPFS, and OS. In multivariate analysis, miR-100 expression was identified as an independent prognostic factor for all LPFS, DPFS, and OS.

These findings show the reduced expression of miR-100 in human ESCC tissues and suggest a crucial role of its downregulation in ESCC progression and prognosis. More interestingly, the detection of miR-100 expression may be used to efficiently screen those ESCC patients who would benefit from radiotherapy.