Influence of miR-199a on rats with non-small cell lung cancer via regulating the HIF-1α/VEGF signaling pathway

Micro-ribonucleic acids (miRNAs) are involved in the occurrence of various cancers, and the hypoxia-inducible factor 1-α (HIF-1α) is the main regulator of cell proliferation induced by hypoxia. The relationships of miR-199a and HIF-1α expressions with non-small cell lung cancer (NSCLC) remain unclear, so they were explored in this work.

On the basis of establishing the rat model of NSCLC, the messenger RNA (mRNA) expressions of miR-199a, HIF-1α and the vascular endothelial growth factor (VEGF) were analyzed in NSCLC rats, and the correlations of miR-199a with the mRNAs of HIF-1α and VEGF and cancer staging were investigated. To further study the role of miR-199a in NSCLC cell proliferation via the HIF-1α/VEGF signaling pathway, NSCLC cells were treated with the signaling pathway inhibitor and transfected with miR-199a mimics, respectively. Also,  the roles of the inhibitor PX-478 and miR-199a mimics in the expressions of miR-199a, HIF-1α, and VEGF proteins, as well as their influences on cell proliferation ability were detected.

In NSCLC rats, the expression of miR-199a was substantially decreased (p<0.01), but the expressions of HIF-1α and VEGF were notably raised (p<0.01). MiR-199a was negatively correlated with the expression of VEGF. As cancer developed, the expression of miR-199a was gradually lowered, but the expressions of HIF-1α and VEGF were gradually increased. Both HIF-1α/VEGF signaling pathway inhibitor PX-478 and miR-199a mimics significantly reduced the expressions of HIF-1α and VEGF proteins (p<0.01) and suppressed the cell proliferation activity.

MiR-199a prevents the proliferation of NSCLC cells via the targeted down-regulation of the HIF-1α/VEGF signaling pathway.