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.