Clinical impact of circulating miR-18a in plasma of patients with oesophageal squamous cell carcinoma.

BACKGROUND: Several recent studies demonstrated that microRNAs are stably detectable in plasma/serum. We tested whether miR-18a, which is located in the miR-17-92 cluster and reported to be highly expressed in tissues of oesophageal squamous cell carcinoma (ESCC), served as a plasma biomarker in patients with ESCC. METHODS: This study was divided into three steps: (1) confirmation of higher miR-18a levels in primary ESCC tissues and cell lines than normal ESCC tissues and a human fibroblast cell line. (2) Evaluation of the plasma miR-18a assay using quantitative RT-PCR by comparing results from 106 consecutive patients with ESCC and 54 healthy volunteers. (3) Evaluation of the assay for monitoring tumour dynamics in patients with ESCC. RESULTS: (1) Expression of miR-18a was significantly higher in ESCC tissues (P=0.0020) and ESCC cell lines (P=0.0121) than normal tissues and fibroblasts. (2) Plasma concentrations of miR-18a were significantly higher in ESCC patients than healthy volunteers (P<0.0001; ESCC patients vs healthy volunteers (mean±s.d.): 11.77±13.45 vs 0.73±0.54 amol µl(-1)). The value of the area under the receiver-operating characteristic (ROC) curve (AUC) was 0.9449. Furthermore, the ROC curves to detect early ESCC such as pTis-1 and pStage0-I showed AUCs of 0.9479 and 0.9642, respectively. (3) Plasma levels of miR-18a were significantly lower in postoperative samples than preoperative samples (P=0.0076). CONCLUSION: Plasma miR-18a may be a very useful biomarker for cancer detection and the monitoring of tumour dynamics in patients with ESCC.

Clinical impact of circulating miR-221 in plasma of patients with pancreatic cancer.

BACKGROUND: Several recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in plasma/serum. We tested miR-221 and miR-375, which are frequently reported to be highly and poorly expressed in pancreatic cancer (PCa), as candidates for plasma biomarkers in PCa. METHODS: This study was divided into three parts: (1) Confirmation of higher miR-221 levels in primary PCa tissue and cell lines than normal pancreatic tissues. (2) Evaluation of plasma miR-221 and miR-375 concentrations by comparing results from 47 consecutive PCa patients and 30 healthy volunteers. (3) Evaluation of the assay for monitoring tumour dynamics in PCa patients. RESULTS: (1) Expression of miR-221 was significantly higher in PCa tissues and cell lines than normal pancreatic tissues. (2) Plasma miR-221 concentrations were significantly higher in PCa patients than that in benign pancreatic tumours (P=0.016) and controls (P<0.0005), while plasma miR-375 concentrations tended to be lower in PCa patients (P=0.064), and the miR-221/miR-375 ratio was significantly higher (P<0.0001) in PCa patients than in controls. (3) Plasma miR-221 concentrations were significantly reduced in postoperative samples (P=0.018). Furthermore, PCa patients with high plasma miR-221 concentrations had significant correlation with distant metastasis (P=0.041), and non-resectable status (P=0.021). CONCLUSION: Plasma miR-221 could be a useful biomarker for cancer detection, monitoring tumour dynamics and predicting malignant outcomes in PCa patients, and may contribute to clinical decision making in PCa treatments.

Detection of gastric cancer-associated microRNAs on microRNA microarray comparing pre- and post-operative plasma.

BACKGROUND: Recently, it was reported that plasma microRNAs (miRNAs) are low-invasive useful biomarkers for cancer. We attempted to isolate gastric cancer (GC)-associated miRNAs comparing pre- and post-operative paired plasma, thereby excluding the possible effects of individual variability. METHODS: This study was divided into four steps: (1) microarray analysis comparing pre- and post-operative plasma; (2) validation of candidate miRNAs by quantitative RT-PCR; (3) validation study of selected miRNAs using paired plasma; and (4) comparison of the levels of selected miRNAs in plasma between healthy controls and patients. RESULTS: From the results of microarray analysis, nine candidate miRNAs the levels of which were markedly decreased in post-operative plasma were selected for further studies. After confirmation of their post-operative marked reduction, two candidate miRNAs, miR-451 and miR-486, were selected as plasma biomarkers, considering the abundance in plasma, and marked decrease in post-operative samples. In validation, the two miRNAs were found to decrease in post-operative plasma in 90 and 93% of patients (both P<0.01). In comparison with healthy controls, the levels of both miRNAs were found to be significantly higher in patients, and the area under the curve values were high at 0.96 and 0.92. CONCLUSION: Plasma miR-451 and miR-486 could be useful blood-based biomarkers for screening GC.

Novel diagnostic value of circulating miR-18a in plasma of patients with pancreatic cancer.

BACKGROUND: Several recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in the plasma/serum. We hypothesised that miR-18a in the plasma is a potential biomarker in patients with pancreatic cancer. METHODS: miR-18a is located in the miR-17-92 cluster and reported to be highly expressed in pancreatic cancer tissues. This study was divided into three parts: (1) Confirmation of higher miR-18a levels in primary pancreatic cancer tissues and cell lines than in normal pancreatic tissues and a human fibroblast cell line. (2) Evaluation of the plasma miR-18a assay using quantitative RT-PCR by comparing plasma results obtained from 36 patients with pancreatic cancer and from 30 healthy volunteers. (3) Evaluation of the assay for monitoring tumour dynamics in patients with pancreatic cancer. RESULTS: (1) The expression of miR-18a was significantly higher in pancreatic cancer tissues (P=0.012) and pancreatic cancer cell lines (P=0.015) than in normal tissues and fibroblasts. (2) Plasma concentrations of miR-18a were significantly higher in pancreatic cancer patients than in controls (P<0.0001). The value of the area under the receiver-operating characteristic curve (AUC) was 0.9369. (3) Plasma levels of miR-18a were significantly lower in postoperative samples than in preoperative samples (P=0.0077). CONCLUSION: Circulating miR-18a might provide new complementary tumour markers for pancreatic cancer.

Circulating microRNAs in plasma of patients with oesophageal squamous cell carcinoma.

BACKGROUND: Several recent studies demonstrated that microRNAs (miRNAs) are stably detectable in plasma/serum. We hypothesised that plasma miRNAs concentrations contributed to potential biomarkers in patients with oesophageal squamous cell carcinoma (ESCC). METHODS: We selected three oncogenic miRNAs (miR-21, miR-184, miR-221) and one tumour suppressive miRNA (miR-375), which are frequently reported in squamous cell carcinoma, as candidate targets for this plasma miRNA assay. This study was divided into three steps: (1) Determination of appropriate plasma miRNAs in preliminary tests. (2) Evaluation of whether the plasma miRNA assays could monitor tumour dynamics. (3) Validation study on the clinical application of plasma miRNA assays in 50 ESCC patients and 20 healthy volunteers. RESULTS: (1) In preliminary tests, the plasma level of miR-21 was significantly higher (P=0.0218) and that of miR-375 (P=0.0052) was significantly lower in ESCC patients than controls. (2) The high plasma miR-21 levels reflected tumour levels in all cases (100%). The plasma level of miR-21 was significantly reduced in postoperative samples (P=0.0058). (3) On validation analysis, the plasma level of miR-21 tended to be higher in ESCC patients (P=0.0649), while that of miR-375 was significantly lower (P<0.0001) and the miR-21/miR-375 ratio was significantly higher (P<0.0001) in ESCC patients than in controls. The value of the area under the receiver-operating characteristic curve (AUC) was 0.816 for the miR-21/miR-375 ratio assay. Patients with a high plasma level of miR-21 tended to have greater vascular invasion (P=0.1554) and to show a high correlation with recurrence (P=0.0164). CONCLUSION: Detection of circulating miRNAs might provide new complementary tumour markers for ESCC.

Prediction of CCND1 amplification using plasma DNA as a prognostic marker in oesophageal squamous cell carcinoma.

BACKGROUND: We aimed to develop a new biomarker to predict cyclin D1 (CCND1) status using plasma DNA in oesophageal squamous cell carcinoma (ESCC) patients. METHODS: We evaluated the ratio of the CCND1 (11q13) dosage to the dopamine receptor D2 (DRD2; 11q22-23) dosage (C/D ratio) as CCND1 copy number. This study was divided into three steps: (1) Determination of a cutoff value for the C/D ratio in test scale; (2) Comparison of the C/D ratio in between plasma samples and cancer tissues in ESCC patients showing high plasma C/D ratio; (3) Validation study of the clinical application of the plasma C/D ratio as a diagnostic and prognostic marker, by comparing with clinicopathologic factors in 96 ESCC patients. RESULTS: The plasma C/D ratio was significantly higher in the ESCC group than the controls (P=0.0134). A high plasma C/D ratio reflected the tumour C/D ratio, and significantly correlated with a poorer prognosis (P=0.0186). Moreover, the high C/D ratio was found to be an independent prognostic factor on multivariate analysis (P=0.0266; hazard ratio 5.988). CONCLUSION: Prediction of CCND1 amplification using plasma DNA is thought to be a promising prognostic biomarker in ESCC patients.

Circulating microRNAs in plasma of patients with gastric cancers.

BACKGROUND: We examined plasma microRNA (miRNA) concentrations from patients with gastric cancers (GCs) to assess their clinical application for diagnosing and monitoring diseases. METHODS: We initially investigated the appropriateness of plasma miRNA assay, and then compared plasma miRNA results with the expressions in cancer tissues from eight GC patients, and also compared plasma miRNAs between pre- and post-operative paired samples from 10 GC patients. Then, plasma miRNAs (miR-17-5p, miR-21, miR-106a, miR-106b and let-7a) were analysed in 69 GC patients and 30 healthy volunteers in total. RESULTS: The initial analysis showed that miRNAs were stable and detectable in all plasma samples, and the plasma miRNA levels reflected the tumour miRNAs in most cases. The levels of these miRNAs were significantly reduced in post-operative samples. In large-scale analysis, the plasma concentrations of miRNAs (miR-17-5p, miR-21, miR-106a, miR-106b) were significantly higher in GC patients than controls (P=0.05, 0.006, 0.008 and <0.001 respectively), whereas let-7a was lower in GC patients (P=0.002). The values of the area under the receiver-operating characteristic curve were 0.721 for the miR-106b assay and 0.879 for the miR-106a/let-7a ratio assay. CONCLUSION: Detection of circulating miRNAs might provide new complementary tumour markers for GC.

Role of leukotriene B4 in bronchial hyperresponsiveness induced by interleukin-8.

Repeated intranasal administration of interleukin 8 (IL-8) induces bronchial hyperresponsiveness (BHR) accompanied by lower airway neutrophil accumulation (ANA) in guinea-pigs. Leukotriene B4 (LTB4) is a chemotactic factor for neutrophils. To elucidate whether LTB4 and neutrophil elastase are involved in the IL-8-induced BHR and ANA, the effects of a LTB4 antagonist (ONO-4057) and a neutrophil elastase inhibitor (ONO-5046) on the responses were examined. IL-8 (5 microg x kg[-1]) was administered intranasally to guinea-pigs twice weekly for 3 weeks. One day after the last administration, animals were anaesthetized and artificially ventilated through tracheal cannulae, and lateral pressure at the tracheal cannula (Pao) was measured as an overall index of airway responses to inhaled histamine. ONO-4057 (2 or 20 mg x kg[-1]) or ONO-5046 (30 or 300 mg x kg[-1]) was administered intraperitoneally 24 and 1 h before anaesthesia. ONO-4057, but not ONO-5046, significantly inhibited the IL8-induced BHR and ANA, assessed by bronchoalveolar lavage, in a dose-dependent manner. These findings suggest that interleukin 8 causes bronchial hyperresponsiveness and airway neutrophil accumulation in guinea-pigs in vivo. In part this appears to be due to release of leukotriene B4, whereas it may not be mediated by neutrophil elastase.

Effect of surfactant inhalation on allergic bronchoconstriction in guinea pigs.

BACKGROUND: In the small airway, surfactant reduces surface tension, prevents liquid filling of bronchioles, thereby maintaining patency in the small airways. Recent reports demonstrated that surfactant dysfunction develops in experimental asthma in immunized guinea pigs. However, there are few reports concerning surfactant and lung function in an experimental asthma model. OBJECTIVE: To examine whether inhaled surfactant improves lung mechanics in antigen-induced bronchoconstriction in guinea pigs. METHOD: We developed a passively immunized guinea pig model for allergic bronchoconstriction induced by antigen inhalation. Using this model, we investigated the effect of inhaled exogenous surfactant, surfactant TA, on the airway opening pressure (Pao) after antigen challenge. RESULTS: Aerosol antigen challenge produced a gradual and long-lasting increase in Pao. Twenty minutes after antigen challenge, aerosolized surfactant TA, 20 mg/ml, was inhaled for 90 s, and it significantly reduced the Pao by 32.8% in 12 min, while a 10.2% reduction was observed in a control group in the same period. When surfactant TA was administered by 90-s inhalation before antigen challenge, it inhibited the Pao increase in a dose-dependent manner: mean inhibitory rates of Pao were 33.6% in surfactant TA 10 mg/ml and 61.9% in surfactant TA 20 mg/ml, respectively. CONCLUSION: Inhaled surfactant showed preventive and recovery effects on antigeninduced bronchoconstriction in an immunized guinea pig model.

Role of sensory neuropeptides in post-allergic propranolol-induced bronchoconstriction in guinea pigs in vivo.

BACKGROUND: Administration of propranolol can provoke bronchoconstriction in asthmatic patients. We hypothesized that such bronchoconstriction may result from the inflammatory mediators released by an allergic reaction. We recently developed a guinea pig model for propranolol-induced bronchoconstriction (PIB). Neuropeptides which are released from C-fibre nerve endings have been postulated to induce bronchial hyperresponsiveness through neurogenic inflammation. OBJECTIVE: The purpose of this study was to examine whether sensory neuropeptides are involved in the development of PIB after allergic reaction. METHODS: Propranolol at a concentration of 10 mg/ml was inhaled 20 min after antigen challenge in passively sensitized, anaesthetized and artificially ventilated guinea pigs. The animals were treated intravenously with a NK1 and NK2 dual antagonist, FK224, in a dose of 1 or 10 mg/kg or vehicle or a selective NK1 antagonist, FK888, in a dose of 1 or 10 mg/kg or vehicle 10 min before or 15 min after antigen challenge. RESULTS: Propranolol inhaled 20 min after antigen challenge caused bronchoconstriction. FK224 or FK888 administered 15 min after antigen challenge as well as 10 min before antigen challenge did not reduce the PIB. CONCLUSION: We conclude that neuropeptides such as neurokinin A and substance P do not directly contribute to the development of PIB after allergic reaction.

Involvement of PAF in postallergic propranolol-induced bronchoconstriction in guinea-pigs.

Administration of propranolol can provoke bronchoconstriction in asthmatic patients. Recently, we successfully developed a guinea-pig model for propranolol-induced bronchoconstriction (PIB). We hypothesized that such bronchoconstriction may result from the inflammatory mediators released by an allergic reaction. The purpose of this study was to examine the role of platelet-activating factor (PAF) in the development of PIB after allergic reaction. Propranolol, at a concentration of 10 mg.mL-1 was inhaled 20 min after antigen challenge in passively sensitized, anaesthetized and artificially-ventilated guinea-pigs. The animals were treated intravenously with PAF antagonists, E6123 (1 and 10 micrograms.kg-1) or Y-24180 (1 and 10 mg.kg-1), 10 min before or 15 min after antigen challenge. Propranolol inhaled 20 min after antigen challenge caused bronchoconstriction. E6123 and Y-24180 administered 15 min after antigen challenge as well as 10 min before antigen challenge reduced the PIB in a dose-dependent manner. We conclude that platelet-activating factor may contribute to the development of propranolol-induced bronchoconstriction after allergic reaction in our guinea-pig model.

Sensory neuropeptides are not directly involved in bronchial hyperresponsiveness induced by interleukin-8 in guinea-pigs in vivo.

BACKGROUND: Interleukin-8 (IL-8) has been shown to be a chemotactic factor for neutrophils, T-lymphocytes and eosinophils. Repeated intranasal administration of IL-8 enhances bronchial responsiveness to inhaled histamine in guinea-pigs. Neuropeptides which are released from C-fibre nerve-endings have been postulated to induce bronchial hyperresponsiveness through neurogenic inflammation. OBJECTIVE: This study was conducted to examine whether sensory neuropeptides are involved in the IL-8-induced bronchial hyperresponsiveness. METHODS: IL-8 at a dose of 5 micrograms/kg was administered intranasally to guinea-pigs twice a week for 3 weeks. One day after the last administration, animals were anesthetized and artificially ventilated through tracheal cannula, and lateral pressure at the tracheal cannula (Pao) was measured as an overall index of airway responses to increasing concentrations of inhaled histamine (25, 50, 100, and 200 micrograms/mL). A NK1 and NK2 dual antagonist FK224 (10 mg/kg), a selective NK1 antagonist FK888 (10 mg/kg) or vehicle was intravenously administered 10 min before measurement of bronchial responsiveness. RESULTS: The IL-8 treatment significantly enhanced bronchial responsiveness to histamine (ANOVA P < 0.01). FK224 or FK888 did not alter the IL-8-induced bronchial hyperresponsiveness. CONCLUSION: We conclude that repeated intranasal administration of IL-8 causes bronchial hyperresponsiveness (BHR) and that neuropeptides such as neurokinin A and substance P do not directly contribute to the development of BHR induced by IL-8.