LncRNA PVT1 regulate expression of HIF1α via functioning as ceRNA for miR‑199a‑5p in non‑small cell lung cancer under hypoxia.

Non‑small cell lung cancer (NSCLC) represents one of the most important causes of cancer mortality in the world, and leads to the largest number of deaths in all kinds of lung cancer. Hypoxia has been confirmed to be a characteristic feature of NSCLC and has been shown to decrease the therapeutic efficacy of radiotherapy and some forms of chemotherapy. Previous studies revealed that many miRNAs have been proven to be involved in the molecular regulation of hypoxia and to affect the protein expression level of HIF‑1α. Here, we demonstrated that miR‑199a‑5p downregulated HIF‑1α expression and was involved in regulating the proliferation of NLSCS cell under hypoxia through downregulation of HIF‑1α. Recently, PVT1 has been proposed to function as a molecular sponge by competitively binding miR‑199a‑5p using miRcode. In this study, we confirmed that PVT1 was overexpressed in the hypoxic lung cancer cells, and then we further demonstrated that PVT1 functioned as competing endogenous (ce)RNA for miR‑199a‑5p, upregulated expression of its endogenous targets HIF‑1α and inhibited its function. Collectively, our study suggested that PVT1 promotes expression of HIF‑1α in NSCLC by functioning as ceRNA of miR‑199a‑5p. These findings support the hypothesis that PVT1 is a vital potential target for hypoxia therapy.