Detection of cancer embryo antigen and endothelin-1 in exhaled breath condensate: A novel approach to investigate non-small cell lung cancer. Mol Clin Oncol. 2016;5:124-128. [PMID: 27330782 DOI: 10.3892/mco.2016.902]

The Role of Exhaled Breath Condensate in Chronic Inflammatory and Neoplastic Diseases of the Respiratory Tract

Asthma and chronic obstructive pulmonary disease (COPD) are among the most common chronic respiratory diseases. Chronic inflammation of the airways leads to an increased production of inflammatory markers by the effector cells of the respiratory tract and lung tissue. These biomarkers allow the assessment of physiological and pathological processes and responses to therapeutic interventions. Lung cancer, which is characterized by high mortality, is one of the most frequently diagnosed cancers worldwide. Current screening methods and tissue biopsies have limitations that highlight the need for rapid diagnosis, patient differentiation, and effective management and monitoring. One promising non-invasive diagnostic method for respiratory diseases is the assessment of exhaled breath condensate (EBC). EBC contains a mixture of volatile and non-volatile biomarkers such as cytokines, leukotrienes, oxidative stress markers, and molecular biomarkers, providing significant information about inflammatory and neoplastic states in the lungs. This article summarizes the research on the application and development of EBC assessment in diagnosing and monitoring respiratory diseases, focusing on asthma, COPD, and lung cancer. The process of collecting condensate, potential issues, and selected groups of markers for detailed disease assessment in the future are discussed. Further research may contribute to the development of more precise and personalized diagnostic and treatment methods.

Significance of vascular endothelium growth factor testing in exhaled breath condensate of patients with acute respiratory distress syndrome

OBJECTIVE:

We aimed to observe and investigate the clinical significance of vascular endothelium growth factor (VEGF) levels in exhaled breath condensate (EBC) from patients with acute respiratory distress syndrome (ARDS).

METHODS:

An improved EcoScreen condenser was used to collect EBC from 31 ARDS patients on mechanical ventilation and from 22 healthy subjects. Serum and EBC VEGF levels were analyzed with ELISA. VEGF levels in the EBC of patients with different grades of lung injuries were analyzed. The correlation between VEGF levels and clinical indicators was analyzed.

RESULTS:

Serum and EBC VEGF levels were linearly and positively correlated with a correlation coefficient of 0.694 (P< 0.01). The VEGF level in the EBC of ARDS patients was significantly lower than that in the control group (P< 0.01). The VEGF level in the EBC of the mild ARDS group was higher than that in the moderate-severe ARDS group (P< 0.01). The VEGF level in the EBC of the survival group was higher than that in the mortality group. The VEGF level in the EBC of ARDS patients was positively correlated with PaO2/FiO2 and PaO2 and was negatively correlated with lung injury score (LIS) and A-aDO2/PaO2.

CONCLUSION:

The changes in VEGF levels in the EBC of ARDS patients can Respiratory Medicine, reflect the severity of lung injury. Therefore, VEGF level in EBC can be used as an auxiliary index for judging the severity and prognosis of ARDS patients.

Surface-enhanced electrochemiluminescence combined with resonance energy transfer for sensitive carcinoembryonic antigen detection in exhaled breath condensates

The detection of biomarkers in exhaled breath condensates (EBCs) is regarded as a promising non-invasive diagnostic approach. However, the ultralow concentration of biomarkers in EBCs is a great challenge. Herein, a sensitive dual signal amplification strategy was developed based on surface-enhanced electrochemiluminescence (SEECL) combined with resonance energy transfer (RET). Gold nanoparticles-functionalized graphite-like carbon nitride nanohybrids (Au-g-C₃N₄ NHs) could be used as an energy transfer donor because of the good overlap between its emission peak and the absorption peak of tris(2,2'-bipyridine)ruthenium dichloride (Ru(bpy)₃Cl₂) at 460 nm. Gold-silicon dioxide core-shell nanoparticles doped with Ru(bpy)₃²⁺(Au@SiO₂-Ru) were employed as an energy transfer acceptor emitting at 620 nm. Moreover, the signals at 620 nm emitted by Ru (bpy)₃²⁺ were enhanced by 5 times, attributed to the localized surface plasmon resonance (LSPR) of gold nanoparticles (Au NPs). The detection of carcinoembryonic antigen (CEA) was performed by using two aptamers as the recognition unit; whereby aptamer 1 (Apt1) was modified on the surface of Au-g-C₃N₄ NHs, and aptamer 2 (Apt2) was banded on the surface of Au@SiO₂-Ru. In the presence of CEA, a sandwich structure was formed between Au-g-C₃N₄ NHs-Apt1-CEA and Apt2-Au@SiO₂-Ru, which resulted in an ultrasensitive detection of CEA. The proposed electrochemiluminescence sensor showed a wide linear relationship with the CEA concentration in the range from 1.0 pg mL^-1 to 5.0 ng mL^-1, with a limit of detection (LOD) of 0.3 pg mL^-1. Finally, the practicality of the proposed sensor was demonstrated to detect CEA in EBCs, and the obtained results were in good agreement with the enzyme-linked immunosorbent assay (ELISA) method.

Sleeve gastrectomy ameliorates endothelial function and prevents lung cancer by normalizing endothelin-1 axis in obese and diabetic rats

BACKGROUND

Previous evidence has implied that obesity is an independent risk factor for developing cancer. Being closely related to obesity, type 2 diabetes mellitus provides a suitable environment for the formation and metastasis of tumors through multiple pathways. Although bariatric surgeries are effective in preventing and lowering the risk of various types of cancer, the underlying mechanisms of this effect are not clearly elucidated.

AIM

To uncover the role and effect of sleeve gastrectomy (SG) in preventing lung cancer in obese and diabetic rats.

METHODS

SG was performed on obese and diabetic Wistar rats, and the postoperative transcriptional and translational alterations of the endothelin-1 (ET-1) axis in the lungs were compared to sham-operated obese and diabetic rats and age-matched healthy controls to assess the improvements in endothelial function and risk of developing lung cancer at the postoperative 4^th, 8^th, and 12^th weeks. The risk was also evaluated using nuclear phosphorylation of H2A histone family member X as a marker of DNA damage (double-strand break).

RESULTS

Compared to obese and diabetic sham-operated rats, SG brought a significant reduction to body weight, food intake, and fasting blood glucose while improving oral glucose tolerance and insulin sensitivity. In addition, ameliorated levels of gene and protein expression in the ET-1 axis as well as reduced DNA damage indicated improved endothelial function and a lower risk of developing lung cancer after the surgery.

CONCLUSION

Apart from eliminating metabolic disorders, SG improves endothelial function and plays a protective role in preventing lung cancer via normalized ET-1 axis and reduced DNA damage.

Epidermal Growth Factor in Exhaled Breath Condensate as Diagnostic Method for Non-Small Cell Lung Cancer

OBJECTIVE

Lung cancer is one of the most common malignant tumors in humans. Finding a highly sensitive and specific marker is very important. This study investigated the clinical significance of epidermal growth factor in exhaled breath condensate and serum of patients with non-small cell lung cancer.

METHODS

From October 17, 2013, to June 5, 2017, exhaled breath condensate and blood samples from 155 patients with non-small cell lung cancer, 63 patients with benign pulmonary nodules, and 115 healthy controls were collected using a breath condenser. Each sample was analyzed by enzyme-linked immunosorbent assay.

RESULTS

Epidermal growth factor level in the exhaled breath condensate from the non-small cell lung cancer group (197.86 ± 60.67 pg/mL) was higher than that in the healthy group (124.75 ± 36.09 pg/mL), P < .05. Epidermal growth factor level in the exhaled breath condensate of the smoking group (208.85 ± 40.94 pg/mL) was higher than that of the nonsmoking group (185.52 ± 36.88 pg/mL), P < .05. Epidermal growth factor level in the exhaled breath condensate in phases III and IV of non-small cell lung cancer group (212.17 ± 35.41 pg/mL) was higher than that in phases I and II (173.91 ± 38.08 pg/mL), P < .05. Epidermal growth factor level in the exhaled breath condensate of the death group (241.05 ± 27.19 pg/mL) was higher than that of the survival group (188.75 ± 37.07 pg/mL), P < .05. The epidermal growth factor exhaled breath condensate levels were positively correlated with the serum epidermal growth factor levels with a correlation coefficient of 0.495 (P < .05). The sensitivity and specificity of epidermal growth factor exhaled breath condensate test were 80.0% and 89.6%, respectively.

CONCLUSION

The detection of epidermal growth factor level in exhaled breath condensate exhibits is important in the diagnosis, disease monitoring, and prognosis of non-small cell lung cancer.

Clinical value of exhaled breath condensate let-7 in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most common causes of tumor-associated mortality worldwide. Early diagnosis is the key focus for improving prognosis. In the present study, the association between exhaled breath condensate (EBC) let-7 and NSCLC diagnosis and clinicopathologic characteristics was investigated in order to explore non-invasive simple technological therapeutic methods. The expression levels of let-7 from 180 samples were analyzed using the reverse transcription-quantitative polymerase chain reaction (RT-qPCR), consisting of 30 patients with NSCLC (lung cancer and para-carcinoma tissues, serum and EBC) and 30 healthy volunteers (serum and EBC). The results revealed that the let-7 levels in tumor tissues, serum, and EBC in NSCLC were significantly decreased compared with the control group (all, P<0.001). The let-7 expression in lung cancer tissue, serum, and EBC in NSCLC decreased alongside the progression of disease (tumor-node-metastasis stage and lymph node metastasis; all P<0.05). No significant association between let-7 expression and other clinicopathologic characteristics (age, sex, smoking status and histopathologic classification) was identified. A receiver operating characteristic curve (ROC) was used to present data and the area under the curve (AUC) of lung cancer tissue let-7 was 0.894, and the specificity and sensitivity were 90% and 93.3%, respectively. The AUC of serum let-7 in NSCLC diagnosis was 0.771, and the specificity and sensitivity were 86.7% and 60%, respectively. The AUC of let-7 in EBC was 0.750, and the specificity and sensitivity were 76.7% and 66.7%, respectively. In addition, the let-7 expression in EBC was positively correlated with that in lung cancer tissue (r=0.6048, P<0.001) and positively correlated with that in serum (r=0.6454, P<0.001). Taken together, the results of the present study indicated that detection of let-7 was feasible in EBC and with the advantages associated with EBC, and let-7 in EBC may be a promising biomarker for the diagnosis and evaluation of NSCLC.

Exhaled Breath Condensate: Pilot Study of the Method and Initial Experience in Healthy Subjects

Analysis of Exhaled breath condensate (EBC) is a re-discovered approach to monitoring the course of the disease and reduce invasive methods of patient investigation. However, the major disadvantage and shortcoming of the EBC is lack of reliable and reproducible standardization of the method. Despite many articles published on EBC, until now there is no clear consensus on whether the analysis of EBC can provide a clue to diagnosis of the diseases. The purpose of this paper is to investigate our own method, to search for possible standardization and to obtain our own initial experience. Thirty healthy volunteers provided the EBC, in which we monitored the density, pH, protein, chloride and urea concentration. Our results show that EBC pH is influenced by smoking, and urea concentrations are affected by the gender of subjects. Age of subjects does not play a role. The smallest coefficient of variation between individual volunteers is for density determination. Current limitations of EBC measurements are the low concentration of many biomarkers. Standardization needs to be specific for each individual biomarker, with focusing on optimal condensate collection. EBC analysis has a potential become diagnostic test, not only for lung diseases.

Non-volatile compounds in exhaled breath condensate: review of methodological aspects

In contrast to bronchial and nasal lavages, the analysis of exhaled breath condensate (EBC) is a promising, simple, non-invasive, repeatable, and diagnostic method for studying the composition of airway lining fluid with the potential to assess lung inflammation, exacerbations, and disease severity, and to monitor the effectiveness of treatment regimens. Recent investigations have revealed the potential applications of EBC analysis in systemic diseases. In this review, we highlight the analytical studies conducted on non-volatile compounds/biomarkers in EBC. In contrast to other related articles, this review is classified on the basis of analytical techniques and includes almost all the applied methods and their methodological limitations for quantification of non-volatile compounds in EBC samples, providing a guideline for further researches. The studies were identified by searching the SCOPUS database with the keywords "biomarkers," "non-volatile compounds," "determination method," and "EBC."

The prognostic value of neutrophil to lymphocyte and platelet to lymphocyte ratios for patients with lung cancer

As the leading cause of cancer-associated mortality globally among males in 2012, lung cancer is a disease of particular concern. Previously, the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) were revealed to be prognostic factors for various types of cancer, including lung cancer. In the present study, a retrospective review was conducted with patients who were diagnosed with lung cancer between January 1, 2000 and December 31, 2005 in the Fourth Hospital of Hebei Medical University. A total of 695 patients were included, and the optimal cutoffs of the NLR and the PLR were 6.0 and 248.0, respectively. There were statistically significant associations between tumor-node-metastasis (TNM) stage, surgery, metastasis incidence and NLR (P<0.001). The associations between TNM stage, surgery incidence and PLR were also revealed to be statistically significant (P<0.001). Patients in the low NLR group demonstrated longer overall survival (OS) than patients in the high NLR group (819.57 days vs. 629.86 days, P=0.041). The NLR at diagnosis was demonstrated to be an independent prognostic factor for OS. Thus, the NLR may be a promising approach for predicting the prognosis of patients with lung cancer.