Association between downexpression of MiR-203 and poor prognosis in non-small cell lung cancer patients

Although miR-203 has been proposed as a relevant biomarker for several cancers, the validated prognostic significance of miR-203 in lung cancer remains obscure. Thus, we aimed to identify the relationship between miR-203 expression and clinicopathological significance in non-small cell lung cancer (NSCLC) patients in the current study.

The expression of miR-203 in 125 cases of NSCLC and their paired adjacent non-cancerous tissues was evaluated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Simultaneously, the correlation of miR-203 expression with a variety of clinicopathological factors and patient survival was analyzed. Functionally, in vitro effects of miR-203 on proliferation and viability were explored in lung cancer H460, A549, H1299, PC9 and H292 cells, as assessed by MTS tetrazolium assay and fluorimetric resorufin viability assay, respectively.

The relative level of miR-203 was 6.12 ± 6.25 in NSCLC tissues, remarkably downregulated than that of their paired non-tumorous lung tissues (7.88 ± 5.56, P = 0.019). The area under curve (AUC) of low expression of miR-203 to diagnose NSCLC was 0.622 (95 % CI 0.552–0.692, P = 0.001). MiR-203 expression was negatively correlated to lymphatic metastasis (r = −0.334, P < 0.001), tumor size (r = −0.407, P < 0.001) and clinical TNM stages (r = −0.298, P = 0.001). Furthermore, the survival of the low miR-203 expression group was 4.88 ± 4.38 months, markedly shorter than that of the high expression group (23.35 ± 1.12 months, P < 0.001). The level of miR-203 was an independent prognostic indicator of NSCLC using univariate analysis. MiR-203 mimic could suppress the cell growth of five lung cancer cell lines tested to different degrees in vitro.

MiR-203 could become a prognostic predictor in NSCLC and may be a new target for the molecular therapy of NSCLC patients.