[meta-analysis of serum tumor markers in lung cancer]

Identification of key candidate tumor biomarkers in non-small-cell lung cancer by in silico analysis

Lung cancer is a common malignancy worldwide. The aim of the present study was to investigate differentially expressed genes (DEGs) between non-small-cell lung cancer (NSCLC) and normal lung tissue, and to reveal the potential molecular mechanism underlying NSCLC. The Gene Expression Omnibus database was used to obtain three gene expression profiles (GSE18842, GSE30219 and GSE33532). DEGs were obtained by GEO2R. Gene Ontology and pathway enrichment analyses were performed for DEGs in the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction (PPI) network of DEGs was constructed and analyzed using the Search Tool for the Retrieval of Interacting Genes/Proteins database and Cytoscape software. A survival analysis was performed and protein expression levels of DEGs in human NSCLC were analyzed in order to determine clinical significance. A total of 764 DEGs were identified, consisting of 428 upregulated and 336 downregulated genes in NSCLC tissues compared with normal lung tissues, which were enriched in the 'cell cycle', 'cell adhesion molecules', 'p53 signaling pathway', 'DNA replication' and 'tight junction'. A PPI network of DEGs consisting of 51 nodes and 192 edges was constructed. The top 10 genes were identified as hub genes from the PPI network. High expression of 4 of the 10 hub genes was associated with worse overall survival rate in patients with NSCLC, including CDK1, PLK1, RAD51 and RFC4. In conclusion, the present study aids in improving the current understanding of aberrant gene expression between NSCLC tissues and normal lung tissues underlying tumorgenesis in NSCLC. Identified hub genes can be used as a tumor marker for diagnosis and prognosis or as a drug therapy target in NSCLC.

[Expression and Clinical Significance of MAGE-C2 in Lung Adenocarcinoma]

BACKGROUND

The aim of this study is to detect the expression of melanoma antigen-C2 (MAGE-C2) in lung adenocarcinoma tissues and adjacent non-cancerousous tissues and analyze its clinical significance.

METHODS

The expression level of MAGE-C2 mRNA and MAGE-C2 protein were measured in 87 cases of lung adenocarcinoma tissues and adjacent non-cancerous tissues were detected by Real-time fluorescence quantitative PCR and Western blot.

RESULTS

Over-expression of the MAGE-C2 mRNA and MAGE-C2 protein were observed in lung adenocarcinoma tissues (53/87, 60.9%), but nor in adjacent non-cancerous tissues. The expressions of MAGE-C2 mRNA and MAGE-C2 protein were closely associated with clinical stage, metastasis and differentiation (P<0.05). The expression rate of MAGE-C2 mRNA had no relationship with gender, age, smoking (P>0.05). The expression of MAGE-C2 had an adverse effect on overall survival rate (P<0.05).

CONCLUSIONS

Over-expression of the MAGE-C2 mRNA and protein is existed in lung adenocarcinoma. The high expression of MAGE-C2 may be closely related to the occurrence and development in lung adenocarcinoma. MAGE-C2 may predict a poor prognosis and could be as a novel lung adenocarcinoma molecule marker.
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Expression and significance of squalene epoxidase in squamous lung cancerous tissues and pericarcinoma tissues

BACKGROUND

A high expression of squalene epoxidase (SQLE) is related to tumor occurrence, development, and prognosis in a variety of cancers. In this study, the expression and significance of SQLE was analyzed in patients with squamous lung cancer and pericarcinoma tissues.

METHODS

The SQLE mRNA and protein expression were separately examined by semi-quantitative reverse transcription polymerase chain reaction, fluorescence quantitative polymerase chain reaction and Western blot in 65 cases of squamous cell lung carcinoma tissues and adjacent non-cancerous lung tissues.

RESULTS

The expression of SQLE mRNA and protein in lung squamous cancerous tissues was significantly higher than in pericarcinoma tissues (63.07% vs. 44.61%, P = 0.0348; 67.69% vs. 38.46%, P = 0.0008). The positive expression rate of SQLE mRNA was not associated with gender, age, smoking, or tumor size (P > 0.05). The expression of SQLE mRNA was closely correlated with poor differentiation, clinical stages, and lymphatic metastasis (P < 0.05). The expression of SQLE mRNA was negatively associated with overall survival rate (P < 0.05).

CONCLUSION

A high expression of SQLE was found in squamous lung cancer tissues. The high expression of the SQLE gene may be closely related to the occurrence and development of squamous cell lung carcinoma. SQLE expression predicts a poor prognosis and may serve as a novel lung carcinoma molecule marker.

Diagnostic value of circulating microRNAs for lung cancer: a meta-analysis

BACKGROUND

Lung cancer is a leading cause of cancer mortality, and it shows a high incidence worldwide. Circulating microRNAs have been proposed as diagnostic indicators of lung cancer, but inconsistent results in the literature have prevented their widespread use in diagnosis. The present meta-analysis aimed to systematically evaluate the diagnostic accuracy of circulating microRNAs for lung cancer.

METHODS

Several research databases were searched systematically for studies of the accuracy of circulating microRNAs as diagnostic indicators of lung cancer. Results from different studies were pooled using random-effects models. Summary receiver operating characteristic (SROC) curves were used to assess the overall performance of microRNA-based assays.

RESULTS

Thirteen publications were included in the meta-analysis. The following summary estimates were obtained for the performance of circulating microRNAs in lung cancer diagnosis: sensitivity, 0.85 (95% confidence intervals [CI]: 0.83-0.87); specificity, 0.84 (95% CI: 0.81-0.86); positive likelihood ratio, 5.23 (95% CI: 3.75-7.29); negative likelihood ratio, 0.20 (95% CI: 0.14-0.27); and diagnostic odds ratio, 31.77 (95% CI: 16.98-59.42). The SROC curve indicated a maximum joint sensitivity and specificity of 0.85, with an area under the curve of 0.92.

CONCLUSION

Circulating microRNAs show significant potential as diagnostic markers of lung cancer. The results of this meta-analysis justify larger, more rigorous studies to confirm such a diagnostic role.

[Evaluation of serum cytokines in small cell lung cancer and its clinical significance]

背景与目的

已有的研究表明：小细胞肺癌（small cell lung cancer, SCLC）患者可出现血清细胞因子表达水平的变化，本研究通过检测SCLC患者血清中细胞因子的差异改变，探讨其在SCLC中的诊断价值。

方法

首先使用Reybiotech G6/G7细胞因子芯片对4例SCLC患者、4例健康人和4例炎症患者血清进行细胞因子差异表达筛查，进一步应用酶联免疫吸附法（ELISA试剂盒）对197例SCLC患者、180例正常对照血清以及97例炎性病变患者血清进行验证。

结果

芯片检测120种细胞因子，从有明显差异的细胞因子中选出最有研究价值的4种进行验证，包括尿激酶型纤溶酶原激活剂受体（urokinase plasminogen activator receptor, uPAR）、人瘦素（Leptin）、巨噬细胞刺激蛋白（macrophage stimulating protein α, MSP-α）和巨噬细胞炎症蛋白1β（macrophage inflammatory protein 1β, MIP-1β）。采用ELISA法验证上述结果，SCLC患者血清uPAR较健康人群以及炎症患者增高（P < 0.05），诊断的敏感度为52.93%，特异度为83.36%。Leptin在无体重变化SCLC组较健康人群以及炎症患者增高，诊断的敏感度为50.11%，特异度86.77%；而Leptin在体重下降组较对照组无明显差异。此外，血清MSP-α、MIP-1β水平在三组之间比较无明显差异。

结论

血清uPAR升高在SCLC中具有一定的诊断价值，而Leptin在无体重变化的SCLC中可能具有诊断意义。