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Background: Brain metastasis (BM) is a poor prognostic factor for non-small-cell lung cancer (NSCLC). The efficacy and roles of combining temozolomide (TMZ) with whole brain radiotherapy (WBRT) in protection neurocognitive function (NCF) and improvement quality of life (QOL) were investigated and compared with WBRT alone in the treatment of NSCLC patients with BM.Methods: A total of 238 NSCLC patients with BM were reviewed and categorized into WBRT plus TMZ (RCT) arm and WBRT alone (RT), respectively. The efficacy was evaluated with Pearson chi-square or Fisher's exact tests, Log-rank test and Cox proportional hazards model. NCF was assessed by using revised Hopkins Verbal Learning Test (HVLT-R), Controlled Oral Word Association (COWA) test and Trail-making Test (TMT). QOL was assessed by the Functional Assessment of Cancer Treatment-Lung (FACT-L) Chinese version 4.0 questionnaire.Results: The average intracranial objective response (ORR) and disease control rate (DCR) for all the patients were 26.9 and 95.8%, respectively. The intracranial ORR and DCR for RCT and RT arm were 34.9% vs. 20.2% (p = 0.01) and 98.4% vs. 92.7% (p = 0.03), respectively. The median intracranial progression-free survival (PFS) and overall survival (OS) of NSCLC patients with BM were 5.2 and 7.3 months, respectively. The median PFS of RCT arm was significantly longer than that of RT arm (5.9 vs. 4.9 months, p = 0.002). The median OS of the RCT arm was also slightly longer than that of the RT arm (8.5 vs. 5.9 months), but without statistical significance (p = 0.11). Multivariate analysis indicated that TMZ was a significant factor for PFS. Statistically significant differences on NCF and QOL were observed between CRT and RT arms at 5 months. RCT showed a trend of toxicities increase compared with RT, however, the toxicities were tolerable and manageable.Conclusions: Adding TMZ to WBRT in the treatment of NSCLC patients with BM could improve the intracranial ORR, DCR, and median PFS compared with WBRT alone. Although no remarkable difference on median OS was found, adding TMZ could prevent NCF and QOL from worsening. The side effects increased by adding TMZ, but the difference was not statistical significance and toxicities were well tolerated. [ABSTRACT FROM AUTHOR]

Background: Acquired radioresistance during radiotherapy is considered as the most important reason for local tumor recurrence or treatment failure. Circular RNAs (circRNAs) have recently been identified as microRNA sponges and involve in various biological processes. The purpose of this study is to investigate the role of circRNAs in the radioresistance of esophageal cancer.Methods: Total RNA was isolated from human parental cell line KYSE-150 and self-established radioresistant esophageal cancer cell line KYSE-150R, and hybridized to Arraystar Human circRNA Array. Quantitative real-time PCR was used to confirm the circRNA expression profiles obtained from the microarray data. Bioinformatic tools including gene ontology (GO) analysis, KEGG pathway analysis and network analysis were done for further assessment.Results: Among the detected candidate 3752 circRNA genes, significant upregulation of 57 circRNAs and downregulation of 17 circRNAs in human radioresistant esophageal cancer cell line KYSE-150R were observed compared with the parental cell line KYSE-150 (fold change ≥2.0 and P < 0.05). There were 9 out of these candidate circRNAs were validated by real-time PCR. GO analysis revealed that numerous target genes, including most microRNAs were involved in the biological processes. There were more than 400 target genes enrichment on Wnt signaling pathway. CircRNA_001059 and circRNA_000167 were the two largest nodes in circRNA/microRNA co-expression network.Conclusions: Our study revealed a comprehensive expression and functional profile of differentially expressed circRNAs in radioresistant esophageal cancer cells, indicating possible involvement of these dysregulated circRNAs in the development of radiation resistance. [ABSTRACT FROM AUTHOR]

Background: Acquired radioresistance has significantly compromised the efficacy of radiotherapy for esophageal cancer. The purpose of this study is to investigate the roles of epithelial-mesenchymal transition (EMT) and the Wnt/β-catenin signaling pathway in the acquirement of radioresistance during the radiation treatment of esophageal cancer., Methods: We previously established a radioresistant cell line (KYSE-150R) from the KYSE-150 cell line (a human cell line model for esophageal squamous cell carcinoma) with a gradient cumulative irradiation dose. In this study, the expression of EMT phenotypes and the Wnt/β-catenin signaling pathway proteins were examined by real-time PCR, western blot and immunofluorescence in the KYSE-150R cells. The KYSE-150R cells were then treated with a β-Catenin/Tcf inhibitor FH535. The expressions of nuclear and cytoplasmic β-catenin and EMT markers in KYSE-150R cells were assessed at both mRNA and protein level after FH535 treatment. The radiosensitization effect of FH535 on KYSE-150R was evaluated by CCK8 analysis and a colony forming assay. DNA repair capacities was detected by the neutral comet assays., Results: KYSE-150R cell line displayed obvious radiation resistance and had a stable genetic ability. EMT phenotype was presented in the KYSE-150R cells with decreased E-cadherin and increased snail and twist expressions. The up-regulated expressions of Wnt/β-catenin signaling pathway proteins (Wnt1, FZD1-4, GSK3β, CTNNB1 and Cyclin D1), the increased phosphorylation of GSK3β, and the decreased phosphorylation of β-catenin were observed in KYSE-150R cells compared with KYSE-150 cells, implicating the activation of the Wnt pathway in KYSE-150R cells. The expression of nuclear β-catenin and nuclear translocation of β-catenin from the cytoplasm was decreased after FH535 treatment. FH535 also reversed EMT phenotypes by increasing E-cadherin expression. The cell proliferation rates of KYSE-150R were dose-dependent and the radiation survival fraction was significantly decreased upon FH535 treatment. Neutral comet assays indicated that FH535 impairs DNA double stranded break repair in KYSE-150R cells., Conclusions: Acquisition of radioresistance and EMT in esophageal cancer cells is associated with the activation of the Wnt/β-catenin pathway. EMT phenotypes can be reduced and the radiosensitivity of esophageal cancer cells can be enhanced by inhibiting the Wnt/β-catenin pathway with FH535 treatment.