BackgroundExosomes are 50–150 nm endocytic vesicles secreted by almost all type of cells that carry bioactive molecules from host. These small vesicles are considered to be novel cross-talk circuits established by tumor cells and tumor microenvironment. Previous studies have shown certain biological influence of exosomal programmed cell-death ligand 1 (Exo-PD-L1) on immune suppression and dysfunction. The aim of the current study was to investigate the impact of Exo-PD-L1 and soluble PD-L1 (sPD-L1) on non-small cell lung cancer (NSCLC) and explore the concordance between Exo-PD-L1 and PD-L1 expression in matched tumor tissues in NSCLC patients.Methods85 consecutive patients from April 2017 to December 2017 at General Hospital of Eastern Command Theatre who were primarily diagnosed with NSCLC and 27 healthy individuals were enrolled in this study. Two milliliters of whole blood samples were collected from each participant and further centrifuged. Exosomes were derived from serum using the commercial kit (Total Exosome Isolation Kit), which was further identified by Western blotting analysis (CD63/TSG101), transmission electron microscope analysis (TEM) and nanoparticle tracking analysis (NTA). Exosomes were next solubilized for Exo-PD-L1 detection by enzyme-linked immuno-sorbent assay (ELISA). PD-L1 expression in matched tissue were assessed by PD-L1 immunohistochemistry (IHC) (clone 28-8) assay. Tumor proportion score (TPS) ≥ 1% was deemed as “positive” in this study and TPS < 1% was deemed as “negative”. Written informed consent were obtained before acquisition of all data and biological sample. Data were analyzed using SPSS 20.0 and Graphpad Prism 5 software. Chi square test was conducted to estimate the correlation between Exo-PD-L1 levels, sPD-L1 levels, PD-L1 IHC profiles and clinicopathological features. For all analysis, a two-sided p < 0.05 was considered significant statistically.ResultsExo-PD-L1 levels were higher in NSCLC patients with advanced tumor stage, larger tumor size (> 2.5 cm) (p < 0.001), positive lymph node status (p < 0.05) and distant metastasis (p < 0.05). In contrast, sPD-L1 levels were not different between NSCLC patients and healthy donors, it was not correlated with any clinicopathologic features except for tumor size (> 2.5 cm) (p < 0.05). In addition, Exo-PD-L1 levels showed slight correlation with sPD-L1 levels (Spearman’s correlation at r = 0.3, p = 0.0027) while no correlation with PD-L1 IHC profiles was detected.ConclusionsIn conclusion, Exo-PD-L1, but not sPD-L1, was correlated with NSCLC disease progression, including tumor size, lymph node status, metastasis and TNM stage. However, Exo-PD-L1 was not associated with PD-L1 IHC status.

To evaluate the diagnostic accuracy of computed tomography (CT)-guided percutaneous lung biopsy for solitary pulmonary nodules. Three hundred and eleven patients (211 males and 100 females), with a mean age of 59.6 years (range, 19–87 years), who were diagnosed with solitary pulmonary nodules and underwent CT-guided percutaneous transthoracic needle biopsy between January 2008 and January 2014 were reviewed. All patients were confirmed by surgery or the clinical course. The overall diagnostic accuracy and incidence of complications were calculated, and the factors influencing these were statistically evaluated and compared. Specimens were successfully obtained from all 311 patients. A total of 217 and 94 cases were found to be malignant and benign lesions, respectively, by biopsy. Two hundred and twenty-five (72.3%) carcinomas, 78 (25.1%) benign lesions, and 8 (2.6%) inconclusive lesions were confirmed by surgery and the clinical course. The diagnostic accuracy, sensitivity, and specificity of CT-guided percutaneous transthoracic needle biopsy were 92.9%, 95.3%, and 95.7%, respectively. The incidences of pneumothorax and self-limiting bleeding were 17.7% and 11.6%, respectively. Taking account of all evidence, CT-guided percutaneous lung biopsy for solitary pulmonary nodules is an efficient, and safe diagnostic method associated with few complications.

The recently discovered long noncoding RNAs have the potential to regulate many biological processes, which are aberrantly expressed in many tumor types. Our previous study showed that the long noncoding RNA-growth arrest-specific transcript 5 (GAS5) was decreased in lung cancer tissue, which contributed to the proliferation and apoptosis of nonsmall cell lung cancer (NSCLC). GAS5 was also associated with the prognosis of lung cancer patients. These results suggest that GAS5 may represent a novel prognostic indicator and a target for gene therapy in NSCLC. However, the expression and diagnosis significance of GAS5 in the plasma of NSCLC patients was unknown. The plasma samples were more readily available than the tissue samples in clinical, so we designed the study to investigate the diagnosis value of GAS5 in blood samples. In our study, 90 patients with NSCLC and 33 healthy controls were included. Blood samples were collected before surgery and therapy. We extracted the free RNA in the plasma and analyzed the expression of GAS5 with quantitative reverse transcription PCR. Suitable statistics methods were used to compare the plasma GAS5 levels of preoperative and postoperative plasma samples between the NSCLC patients and healthy controls. Receiver-operating characteristic curve analysis was used to evaluate the diagnostic sensitivity and specificity of plasma GAS5 in NSCLC. The results showed that GAS5 was detectable and stable in the plasma of NSCLC patients. Furthermore, the plasma levels of GAS5 were significantly down-regulated in NSCLC patients compared with healthy controls (P = 0.000). Moreover, GAS5 levels increased markedly on the seventh day after surgery compared with preoperative GAS5 levels in NSCLC patients (P = 0.003). GAS5 expression levels could be used to distinguish NSCLC patients from control patients with an area under the curve of 0.832 (P < 0.0001; sensitivity, 82.2%; specificity, 72.7%). The combination of the GAS5 and carcinoembryonic antigen could produce an area of 0.909 under the receiver-operating characteristic curve in distinguishing NSCLC patients from control subjects (95% confidence interval 0.857–0.962, P = 0.000). We have demonstrated that GAS5 expression was decreased in NSCLC Plasma. Plasma samples were more accessible than tissue samples in clinical; therefore, GAS5 could be an ideal biomarker for the diagnosis of NSCLC.