lncRNA PVT1 Promotes Metastasis of Non-Small Cell Lung Cancer Through EZH2-Mediated Activation of Hippo/NOTCH1 Signaling Pathways.

OBJECTIVE: Although growing evidences have showed that long non-coding RNA (lncRNAs) plasmacytoma variant translocation 1 (PVT1) plays a critical role in the progression of non-small cell lung cancer (NSCLC), there are still many unsolved mysteries remains to be deeply elucidated. This study aimed to find a new underlying mechanism of PVT1 in regulating the tumorigenesis and development of NSCLC. MATERIALS AND METHODS: In this experimental study, Quantitative reverse transcription polymerase chain reaction (qRTPCR) was used to profile the expression of PVT1 in NSCLC tissues and cells. The effects of PVT1 on cell growth, migration and invasion were detected by colony formation assay, Matrigel-free transwell and Matrigel transwell assays, respectively. Changes of the key protein expression in Hippo and NOTCH signaling pathways, as well as epithelialmesenchymal transition (EMT) markers, were analyzed using western blot. Interaction of PVT1 with enhancer of zeste homolog 2 (EZH2) was verified by RNA pull-down, and their binding to the downstream targets was detected by Chromatin Immunoprecipitation (ChIP) assays. RESULTS: These results showed that PVT1 was up-regulated in NSCLC tissue and cell lines, promoting NSCLC cell proliferation, migration and invasion. Knockdown of PVT1 inhibited the expression of Yes-associated protein 1 (YAP1) and NOTCH1 signaling activation. Further, we have confirmed that PVT1 regulated expression of YAP1 through EZH2-mediated miR-497 promoter methylation resulting in the inhibition of miR-497 transcription and its target YAP1 upregulation, and finally NOTCH signaling pathway was activated, which promoted EMT and invasion and metastasis. CONCLUSION: These results suggested that lncRNA PVT1 promotes NSCLC metastasis through EZH2-mediated activation of Hippo/NOTCH1 signaling pathways. This study provides a new opportunity to advance our understanding in the potential mechanism of NSCLC development.

MicroRNA-497-5p negatively regulates the proliferation and cisplatin resistance of non-small cell lung cancer cells by targeting YAP1 and TEAD1.

BACKGROUND: MicroRNAs (miRNAs) are crucial regulators in the pathological processes and drug resistance of lung cancer. In this study, we investigated the role of miR-497-5p in modulating the function of non-small cell lung cancer (NSCLC). METHODS: MiR-497-5p expression in lung cancer tissues and cells was evaluated by qRT-PCR. Cell proliferation was evaluated by CCK-8 assay and colony-formation assay. Cell cycle and cell apoptosis were detected by flow cytometry. The effect of miR-497-5p on the expression of Yes-associated protein 1 (YAP1) and TEA domain family member 1 (TEAD1) was analyzed by qRT-PCR, Western blot and luciferase activity assay. RESULTS: The expression of miR-497-5p was significantly downregulated in lung cancer tissues and cells compared with paired normal tissues and cells. Overexpression of miR-497-5p induced growth retardation and apoptosis of A549 lung cancer cells. Mechanistically, YAP1 and TEAD1 were targeted and downregulated by miR-497-5p. Finally, we found that miR-497-5p increased cisplatin chemosensitivity in A549 cells. CONCLUSIONS: MiR-497-5p suppresses cell proliferation and resistance to cisplatin in NSCLC by downregulating the expression of YAP1 and TEAD1.

[Sevoflurane-N2O inhalation anaesthesia with laryngeal mask airway and propofol-ketamine intravenous anaesthesia in strabismus surgery].

OBJECTIVE: To investigate the advantages and disadvantages of sevoflurane-N2O inhalation anesthesia with laryngeal mask airway (LMA) and propofolketamine total intravenous anaesthesia in children undertaking strabismus surgery. METHODS: Eighty children undertaking strabismus surgery were randomly divided into sevoflurane-N2O inhalation anaesthesia group with LMA (volatile group, n=40) and propofol-ketamine total intravenous anesthesia group (TIVA group, n=40). LMA was used to secure respiratory airway in the volatile group, but LMA or endotracheal intubation was not used in the TIVA group. All children breathed spontaneously during operative period. The anesthesia was maintained with 2%-3% sevoflurane-50% N2O-50% O2 in the volatile group, and continuous intravenous infusion with propofol 5-10 mg/(kg x h) plus ketamine 1-2 mg/(kg x h) in the TIVA group. The incidence of SpO2 less than 95% and the movement of the limbs and head induced by operative stimulation, oculocardiac reflex (OCR) and postoperative vomiting (POV) were recorded in all children. RESULTS: The incidence of limbs and head movement, the incidence of SpO2 less than 95% and OCR were significantly lower in the volatile group than those in the TIVA group (P < 0.01); but the incidence of POV was significantly higher in the volatile group than that in the TIVA group (P < 0.01). CONCLUSION: Sevoflurane-N2O-O2 anesthesia with LMA can secure respiratory airway of patients, avoid hypoxemia, and have good anesthetic quality and low OCR incidence. It is a new anesthesia method with more advantages in children undertaking strabismus surgery, but the prevention and treatment of POV must be noticed.

[Impaired endothelium-dependent vasodilation and arterial elasticity in patients with coronary artery disease].

OBJECTIVE: To investigate the change in endothelium-dependent vasodilation and arterial elasticity and the association between them in patients with coronary artery disease (CAD). METHODS: Thirty patients with CAD and thirty control subjects were recruited for this study. Flow-mediated dilation (FMD) in the brachial artery was evaluated by ultrasound Doppler flow method. They also underwent a non-invasive assessment of C(1) large artery and C(2) small artery indices by using pulse wave analysis. RESULTS: FMD was significantly reduced in CAD group compared with that in control group [(5.17 +/- 2.13)% vs (11.1 +/- 4.36)%, P < 0.05], C(1) large artery elasticity index was similar between the two groups [(11.59 +/- 4.56) ml/mm Hg x 10 vs (12.11 +/- 3.82) ml/mm Hg x 10, P > 0.05]. However, C(2) small artery elasticity index was significantly reduced in CAD group compared with that in control group [(4.20 +/- 1.80) ml/mm Hg x 100 vs (6.26 +/- 2.36) ml/mm Hg x 100, P < 0.05]. There was a positive association between reduced C(2) small artery elasticity index and impaired FMD (r = 0.53, P < 0.05). CONCLUSIONS: There were impaired endothelium-dependent vasodilation and reduced C(2) small artery elasticity index in the patients with CAD, which were closely correlated with each other. The present study suggested that the measurement of C(2) small artery elasticity might be used as a novel index for the determination of endothelial function.

[Change in endothelial progenitor cells and endothelial function in patients with unstable angina pectoris].

OBJECTIVE: To investigate the relationship between endothelial progenitors cells (EPCs) and endothelium-dependent vasodilation in patients with unstable angina pectoris. METHODS: Thirty patients with unstable angina pectoris (UAP) and thirty control subjects were recruited. Flow-mediated dilation (FMD) in the brachial artery was evaluated by using ultrasound Doppler flow method. The number of circulating EPCs was analyzed by flow cytometry analysis. Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture dishes. CD34 antigen of adherent cells was identified by immunohistochemical assay. EPCs were characterized as adherent cells double positive for FITC-UEA-I binding and DiI-acLDL uptake by direct fluorescent staining under inverted fluorescent microscope. RESULTS: FMD was significantly impaired in the UAP group compared with the control group (5.93% +/- 2.67% vs 11.1% +/- 4.36%, P < 0.05). There was no significant difference in NMD between two groups (13.60% +/- 5.03% vs 14.18% +/- 4.50%, P > 0.05). The number of CD34(+) cells significantly increased in the UAP group compared with the control group (0.13% +/- 0.05% vs 0.09% +/- 0.04%, P < 0.05). There was a negative association between impaired FMD and increased CD34(+) cell (r = -0.385, P < 0.05). A positive antigen of CD34 of adhesion cells and double positive adhesion cells were found. CONCLUSION: This study shows that the levels of peripheral CD34(+) cells in patients with UAP increase with an impaired endothelial function. The increase in EPCs may be an important compensatory response to acute coronary ischemia and impaired endothelium in patients with UAP.