Ribonucleotide reductase subunit M2 may play a role as a potential prognostic biomarker in several cancers. In this study, we evaluated whether RRM2 gene expression is associated with the prognosis of patients with lung adenocarcinoma (LUAD) using publicly available data from The Cancer Genome Atlas (TCGA). Wilcoxon signed-rank test and logistic regression were performed to evaluate the association between RRM2 expression and clinical features in patients with LUAD. Kaplan-Meier and Cox regression methods were used to examine the effect of RRM2 expression level in the overall survival, and a nomogram was performed to illustrate the correlation between the RRM2 gene expression and the risk of LUAD. TCGA data set was used for gene set enrichment analysis (GSEA). We also performed a further experiment in vitro to assess the effect of RRM2 expression on the proliferation and invasive abilities of LUAD cells and its key signaling pathway proteins. Our results revealed that the expression level of RRM2 in patients with LUAD was much higher than that in normal tissues ( p = 3.99e-32). High expression of RRM2 was significantly associated with tumor stage (IV vs. I: OR = 3.02, p = 0.012) and TNM classification (T2 vs . T1: OR = 1.88, p = 0.001; N2 vs . N0: OR = 2.69, p < 0.001). Kaplan-Meier survival analysis showed that high expression of RRM2 was associated with a worse prognosis of LUAD compared low expression of RRM2 ( p = 7.86e-04). Multivariate analysis showed that high RRM2 expression was an independent factor affecting overall survival (HR = 1.29, p < 0.001). The association between RRM2 gene expression and the risk of LUAD was presented in a nomogram. GSEA revealed that the cell cycle, p53 signaling pathway, DNA replication, small cell lung cancer, apoptosis, and pathways in cancer were differentially enriched in patients with high expression of RRM2 . RRM2 over-expression promoted the proliferation and invasive abilities of LUAD cells. RRM2 over-expression increased the activation of Bcl-2 and E-cadherin signaling pathways, and reduced the activation of p53 signaling pathway. In summary, high RRM2 expression is an independent predictive factor of poor prognosis in patients with lung adenocarcinoma.

BackgroundHydatid disease is a severe and widespread human cestode infection, and in children, the lung is the most commonly infected organ. In current practice, the standard surgical procedure for the removal of pulmonary hydatid cysts is thoracotomy; therefore, we evaluated the efficacy and safety of video-assisted thoracoscopic surgery (VATS) to treat pediatric pulmonary hydatid disease. To our knowledge, this is the first and large sample comparative study of VATS and thoracotomy for pediatric pulmonary hydatid disease.MethodsIn this study, we retrospectively reviewed 44 (61.1 %) pediatric patients who underwent VATS, and 28 (38.9 %) pediatric patients who underwent conventional thoracotomy from January 2005 to June 2012. Perioperative data, including basic characteristics of patients, the length of hospital stay, intraoperative blood loss, thoracic intubation indwelling time, and complications were compared between VATS and thoracotomy in 72 children with pulmonary hydatid disease.ResultsVATS was found to be a safe technique for the treatment of pediatric pulmonary hydatid disease, with zero intraoperative deaths. In the VATS and thoracotomy groups, the hospital stay durations were 10.50 ± 1.20 days and 17.30 ± 2.75 days, respectively, and occurrence rates of complications were 9.1 % (4/44) and 17.9 % (5/28), respectively. The hospital stays were shorter and the hospitalization costs was reduced for the patients who underwent VATS compared with conventional thoracotomy (P = 0.001). Although no statistically significant difference in the recurrence rates (P = 0.958) and complication incidence (P = 0.273) between the two surgical groups was observed, less intraoperative bleeding, shorter thoracic intubation indwelling time and reduced postoperative pain were observed in the patients who underwent VATS (P = 0.001).ConclusionOur study demonstrates the feasibility and safety of VATS for pediatric pulmonary hydatid disease treatment, providing a practice-changing concept for the treatment of this disease in the community. VATS can be a promising therapeutic tool, by overcoming many of the drawbacks of thoracotomy, and can be used as an alternative to thoracotomy for selected pediatric patients.

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The objective of this study is to investigate relationship between the expressions of heparanase and vascular endothelial growth factor-C (VEGF-C) mRNA and tumorigenesis, progression in human lung cancer. The expressions of heparanase and VEGF-C mRNA in 65 cases of lung cancer (31 cases of squamous cell carcinoma, 25 adenocarcinoma, 3 large cell carcinoma, and 6 small cell carcinoma), adjacent tissues of cancer, and normal tissues were tested by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed by clinico-pathological characteristics and prognosis of lung cancer. The rate of expressions of heparanase and VEGF-C mRNA in tumor tissues (55.4, 61.5 %) was significantly higher than that in adjacent tissues of cancer (12.3, 15.4 %) and normal tissues (3.1, 4.6 %) (P<0.05). It was shown that heparanase and VEGF-C mRNA expressions did not correlate with the pathological type and grade of the tumor (P>0.05), but they correlated with the clinical stage and survival time of the patients (P < 0.05). Overexpression of heparanase and VEGF-C mRNA in lung cancer tissues perhaps participates in regulation of tumorigenesis and progression. The expressions of heparanase and VEGF-C mRNA should be used as a useful marker of the biological behavior of lung cancer and as an independent prognosis factor for the patient's survival.