Overexpression of long non‐coding RNA KCNQ1OT1 is related to good prognosis via inhibiting cell proliferation in non‐small cell lung cancer

BACKGROUND: Lung cancer (LC) is the most common malignancy in the world. Many long non‐coding RNAs (lncRNAs) have been reported to be associated with LC; however, the function of KCNQ1OT1 in LC requires exploration. METHODS: We conducted in silico analysis with data from The Cancer Genome Atlas to investigate the association between KCNQ1OT1 and LC. A Kaplan–Meier plotter was used to analyze the function of KCNQ1OT1 on LC patient prognosis. Quantitative reverse transcription‐PCR (qRT‐PCR) was performed to confirm previous results. An A549 lung cancer cell was transfected with pcDNA‐KCNQ1OT1, and methyl thiazolyl tetrazolium assay was performed to investigate the function of KCNQ1OT1 on cell proliferation. in vivo assay was performed with nude mice. RESULTS: Bioinformatics analysis and qRT‐PCR indicated that KCNQ1OT1 expression was higher in stage I LC patients (P < 0.01), and survival analysis showed that high expression of KCNQ1OT1 in LC patients was associated with better prognosis (P < 0.05). qRT‐PCR showed a negative correlation between KCNQ1OT1 and Ki67 expression and tumor size (P < 0.01), which indicated that KCNQ1OT1 is associated with tumor growth in LC. There was no significant correlation between KCNQ1OT1 level and lymph node metastasis (P > 0.05). KCNQ1OT1 overexpression significantly inhibited cell proliferation and tumor growth in vitro and in vivo (P < 0.05). CONCLUSION: Our preliminary data showed that KCNQ1OT1 is overexpressed in early stage LC and is correlated with better prognosis in LC patients, possibly by suppressing cell proliferation.