Résumé
AIM: To explore the effect of knocking down long intergenic non-coding RNA 00467 on the prognosis of patients with lung adenocarcinoma and its mechanism. METHODS: Quantitative reverse transcription PCR (qRT-PCR) was used to detect the expression level of linc00467 in the plasma of LAD patients and healthy volunteers. The overall survival (OS) was analyzed by Kaplan-Meier survival analysis and log-rank tests. Cell proliferation assays and Xenograft mouse model were used to confirm the effect of linc00467 expression on tumorigenesis in vitro and in vivo.RESULTS: linc00467 expression was up-regulated in the plasma of LAD patients compared with healthy volunteers. In addition, high levels of linc00467 expression were correlated with larger tumour sizes, lymph node metastasis and advanced TNM stages. High levels of linc00467 indicated a poor prognosis in LAD patients, multivariate analyses indicated that linc00467 expression could serve as an independent prognostic factor for overall survival of LAD. Functional experiments showed that knockdown of linc00467 could inhibit LAD cell proliferation in vitro and in vivo. CONCLUSION: linc00467 is involved in the progression of LAD and that linc00467 may be a novel diagnosis biomarker and a potential therapeutic target for LAD.
Résumé
Objective The role of long non-coding RNA Linc00467 in human lung adenocarcinoma is not yet clear.This study was to investigate the expression of long non-coding RNA Linc00467 in human lung adenocarcinoma, its clinical significance, and the effects of Linc00467 on the functions of the tumor and endothelial cells in vitro.Methods Lung adenocarcinoma tissue and normal tissue surrounding the malignance were obtained from 60 patients with pathologically proved stage I-Ⅲa lung adenocarcinoma.Human umbilical vein endothelial cells (HUVECs) were transfected with the over-expressed plasmid pccl-Linc00467 (HUVEC experimental group) or the empty vector pccl (HUVEC control group), A549 cells with Linc00467-siRNA (A549 experimental group) or negative siRNA (A549 control group), and H1299 cells, too, with Linc00467-siRNA (H1299 experimental group) or negative siRNA (H1299 control group).The expression level of Linc00467 in the lung adenocarcinoma tissue was detected by qRT-PCR with an analysis of its correlation with the clinicopathological characteristics of the patients;the influence of Linc00467 on the proliferation of the A549, H1299 and HUVEC cells was assayed with CCK-8;and the role of Linc00467 in the angiogenesis of the HUVECs was assessed by fibrin bead sprouting assay.Results The expression of Linc00467 in the lung adenocarcinoma tissue was 2.72±1.31 times as high as that in the normal lung tissue (P<0.01), and those in the A549 and H1299 cells were 3.45±0.25 and 3.22±0.33 times as high as those in the human bronchial epithelial (HBE) cells (P<0.01).The expression level of Linc00467 was significantly correlated with the tumor size and vascular invasion (P<0.05).After transfection of Linc00467-siRNA, the expressions of Linc00467 in the A549 and H1299 experimental groups were down-regulated by 72% and 68% as compared with those in the A549 and H1299 control groups (P<0.01).The number of living cells was remarkably decreased in the A549 experimental group in comparison with the A549 control at 48 h (1.29±0.07 vs 1.51±0.09), 72 h (1.53±0.15 vs 2.13±0.11), and 96 h after culturing (1.98±0.18 vs 3.02±0.12), and so was it in the H1299 experimental versus the H1299 control group, but markedly increased in the HUVEC experimental versus the HUVEC control group (P<0.05).At 5 days, HUVEC experimental group, as compared with the HUVEC control, showed a significantly increased number of newly formed vascular branches (7.36 vs 4.25/superbead, P<0.01) and relative length of the blood vessels (3.12 vs 1, P<0.01).Conclusion Linc00467 promotes tumor cell proliferation and angiogenesis and is highly expressed in the lung adenocarcinoma tissue, which is correlated with the tumor size and vascular invasion and suggests that Linc00467 could be a potential biomarker and therapeutic target.