Elevated exhalation of hydrogen peroxide in patients with non-small cell lung cancer is not affected by chemotherapy

Protective efficacy of pirfenidone in rats with pulmonary fibrosis induced by bleomycin

BACKGROUND

Bleomycin causes increased production of reactive oxygen species, leads to pulmonary toxicity, fibroblast activation, and fibrosis.

OBJECTIVES

This study aimed to evaluate the protective effect of pirfenidone on bleomycin-induced lung toxicity in rats.

METHODS

Twenty-eight adult rats were randomly divided into 3 groups; Bleomycin (B group, n=10), Bleomycin and Pirfenidone (B-PND group, n=13), and the control group (n=5). The bleomycin regimen was administered for 9 weeks. Pirfenidone was administered at 100 mg/kg daily. Total antioxidant level (TAS), total oxidant level (TOS), tumor necrosis factor (TNF-α), transforming growth factor (TGF-β1), matrix metalloproteinase-2 (MMP-2), plasminogen activator inhibitor (PAI) levels were studied. Histopathologically, sections were stained with Hematoxylin-eosin and Masson-trichrome for grading-scoring according to the Ashcroft score.

RESULTS

Stage 3 fibrosis was observed in 50% of the B group rats, stage 3 and higher fibrosis was never detected in the B-PND group and the difference was statistically significant (p=0.003). When evaluating tissue inflammation, the inflammation was higher in the B-PND group than in the other groups (p<0.001). Pleuritis was detected in all rats in group B, while was not observed in B-PND and control group (p<0.001). The TAS level was found to be significantly higher in group B than in group B-PND (p=0.034), while no difference was found between TOS, TNF-α, MMP-2, PAI, TGF-β1.

CONCLUSIONS

Pirfenidone had a statistically significant protective effect in bleomycin-induced lung fibrosis and pleuritis in rats.  Despite the presence of inflammation in the tissue, no significant changes were observed in inflammation markers in the peripheral blood. Novel serum biomarkers are needed to indicate the presence of inflammation and fibrosis in the lung.

Lung cancer increases H2O2 concentration in the exhaled breath condensate, extent of mtDNA damage, and mtDNA copy number in buccal mucosa

We have shown that the H2O2 concentration in exhaled breath condensate (EBC) in lung cancer patients increases significantly compared to the EBC of healthy people and revealed the correlation between the H2O2 level in the EBC and amount of mtDNA damage in buccal mucosa cells. The H2O2 hyper-production may trigger mitochondrial biogenesis, thereby resulting in an increase in mtDNA copy number. However, we did not observe a significant difference in the studied parameters between smokers and non-smokers. Overall, our data suggest that H2O2 concentration in the EBC, the extent of mtDNA damage, and mtDNA copy number in buccal mucosa could be potential as an early diagnostic marker of lung cancer.

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.

Airborne Particulate Matter (PM10) Inhibits Apoptosis through PI3K/AKT/FoxO3a Pathway in Lung Epithelial Cells: The Role of a Second Oxidant Stimulus

Outdoor particulate matter (PM₁₀) exposure is carcinogenic to humans. The cellular mechanism by which PM₁₀ is associated specifically with lung cancer includes oxidative stress and damage to proteins, lipids, and DNA in the absence of apoptosis, suggesting that PM₁₀ induces cellular survival. We aimed to evaluate the PI3K/AKT/FoxO3a pathway as a mechanism of cell survival in lung epithelial A549 cells exposed to PM₁₀ that were subsequently challenged with hydrogen peroxide (H₂O₂). Our results showed that pre-exposure to PM₁₀ followed by H₂O₂, as a second oxidant stimulus increased the phosphorylation rate of pAKT^Ser473, pAKT^Thr308, and pFoxO3a^Ser253 2.5-fold, 1.8-fold, and 1.2-fold, respectively. Levels of catalase and p27^kip1, which are targets of the PIK3/AKT/FoxO3a pathway, decreased 38.1% and 62.7%, respectively. None of these changes had an influence on apoptosis; however, the inhibition of PI3K using the LY294002 compound revealed that the PI3K/AKT/FoxO3a pathway was involved in apoptosis evasion. We conclude that nontoxic PM₁₀ exposure predisposes lung epithelial cell cultures to evade apoptosis through the PI3K/AKT/FoxO3a pathway when cells are treated with a second oxidant stimulus.

Sera total oxidant/antioxidant status in lung cancer patients

We investigated oxidative stress parameters in the sera of patients with lung cancer and healthy individuals to evaluate their correlations with lung cancer.Ninety-four lung cancer patients and 64 healthy controls were enrolled after obtaining informed consent. Their sera oxidative stress parameters were measured.Total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were significantly different between patients and healthy groups (all P < .001). TAS gradually decreased and TOS and OSI gradually increased from stage I to III, but it did not reach statistical significance (all P > .05). TAS and OSI were significantly different between the nonsmoking and smoking groups, radiotherapy and without radiotherapy groups, chemotherapy and without chemotherapy groups (P < .05), but not TOS (P > .05). In a receiver operating characteristic curve analysis comparing patients with lung cancer with healthy controls, the Youden indices of TOS, TAS, and OSI were 0.541, 0.532, and 1, respectively.The oxidative stress may be correlation with lung cancer staging. Smoking, surgery, radiotherapy, and chemotherapy showed correlation with parts oxidative stress parameters.