While aberrant JAK/STAT signaling is crucial to the development of gastric cancer (GC), its effects on epigenetic alterations of its transcriptional targets remains unclear. In this study, by expression microarrays coupled with bioinformatic analyses, we identified a putative STAT3 target gene, NR4A3 that was downregulated in MKN28 GC daughter cells overexpressing a constitutively activated STAT3 mutant (S16), as compared to an empty vector control (C9). Bisulphite pyrosequencing and demethylation treatment showed that NR4A3 was epigenetically silenced by promoter DNA methylation in S16 and other GC cell lines including AGS cells, showing constitutive activation of STAT3. Subsequent experiments revealed that NR4A3 promoter binding by STAT3 might repress its transcription. Long-term depletion of STAT3 derepressed NR4A3 expression, by promoter demethylation, in AGS GC cells. NR4A3 re-expression in GC cell lines sensitized the cells to cisplatin, and inhibited tumor growth in vitro and in vivo, in an animal model. Clinically, GC patients with high NR4A3 methylation, or lower NR4A3 protein expression, had significantly shorter overall survival. Intriguingly, STAT3 activation significantly associated only with NR4A3 methylation in low-stage patient samples. Taken together, aberrant JAK/STAT3 signaling epigenetically silences a potential tumor suppressor, NR4A3, in gastric cancer, plausibly representing a reliable biomarker for gastric cancer prognosis.

The superlative mechanical properties of spider silk and its conspicuous variations have instigated significant interest over the past few years. However, current attempts to synthetically spin spider silk fibers often yield an inferior physical performance, owing to the improper molecular interactions of silk proteins. Considering this, herein, a post-treatment process to reorganize molecular structures and improve the physical strength of spider silk is reported. The major ampullate dragline silk from Nephila pilipes with a high β-sheet content and an adequate tensile strength was utilized as the study material, while that from Cyrtophora moluccensis was regarded as a reference. Our results indicated that the hydrothermal post-treatment (50–70 °C) of natural spider silk could effectively induce the alternation of secondary structures (random coil to β-sheet) and increase the overall tensile strength of the silk. Such advantageous post-treatment strategy when applied to regenerated spider silk also leads to an increment in the strength by ~2.5–3.0 folds, recapitulating ~90% of the strength of native spider silk. Overall, this study provides a facile and effective post-spinning means for enhancing the molecular structures and mechanical properties of as-spun silk threads, both natural and regenerated.

People can use their web browser or mobile devices to access web services and applications which are built into these servers. Users have to input their identity and password to login the server. The identity and password may be appropriated by hackers when the network environment is not safe. The multiple secure authentication protocol can improve the security of the network environment. Mobile devices can be used to pass the authentication messages through Wi-Fi or 3G networks to serve as a second communication channel. The content of the message number is not considered in a multiple secure authentication protocol. The more excessive transmission of messages would be easier to collect and decode by hackers. In this paper, we propose two schemes which allow the server to validate the user and reduce the number of messages using the XOR operation. Our schemes can improve the security of the authentication protocol. The experimental results show that our proposed authentication protocols are more secure and effective. In regard to applications of second authentication communication channels for a smart access control system, identity identification and E-wallet, our proposed authentication protocols can ensure the safety of person and property, and achieve more effective security management mechanisms.

Erlotinib is a first-generation EGFR (epidermal growth factor receptor) tyrosine kinase inhibitor and have well-established efficacy in non-small cell lung cancer patients with activating EGFR mutations. Afatinib, on the other hand, is a second-generation EGFR tyrosine kinase inhibitor with anti-HER2 activity and was found to be of benefit to patients with advanced lung adenocarcinoma who failed previous gefetinib or erlotinib. In previous study we have demonstrated the in vitro and in vivo radiosensitising activity of afatinib in a murine bladder cancer model. However, the radiosensitizing effect of afatinib and erlotinib, has never been compared in cancer cells including bladder cancer. We performed RTK (Receptor Tyrosine Kinase) antibody arrays to investigate the relative levels of phosphorylation in T24 human bladder cancer cell line. We found that EGFR and HER2 signals were activated after radiation10 Gy. Afatinib 100 nM suppressed both irradiation-induced EGFR and HER2 signals but erlotinib 100 nM only suppressed irradiation-induced EGFR signal. Clonogenic assay of T24 and NTUB1 human bladder cancer cell lines was then examined. Afatinib (100-500 nM) showed better radiosensitizing effect (radiation dose: 2-10 Gy) than erlotinib (300-1500 nM) in both T24 and NTUB1 cells by significantly decreasing the numbers of colonies 7 days after treatment. The effect is more prominent in high doses of afatinib. Flow cytometry was used to determine the distribution of cells among various cell cycle phases. T24 and NTUB1 cells were treated with vehicle, radiation 2.5 Gy, afatinib 200 nM, erlotinib 200 nM or the combination of radiation and afatinib or erlotinib. When compared with radiation or drug alone, treatment combining radiation and afatinib in T24 cells resulted in a significant increase of cells in sub-G1 phase but the phenomenon was not observed in the combination of erlotinib and radiation. A similar trend was found in NTUB1 cells. The results implicated that afatinib might enhance radiation effect by increasing apoptosis in bladder cancer cells. To study the DNA damage status after treatment, we checked intra-nuclear γH2AX foci by mmunofluorescence microscopy. T24 and NTUB1 cells were treated with vehicle, radiation 2.5 Gy, afatinib 100 nM, erlotinib 100 nM or the combination of radiation and afatinib or erlotinib. Radiation alone significantly increased γH2AX foci and combining radiation with afatinib further increased the foci in both T24 and NTUB1 cells. The enhancement was absent in the combination of radiation and erlotinib. Our data clearly show that afatinib, a new generation EGFR tyrosine kinase inhibitor with anti-HER2 activity, is superior to erlotinib as a radiosensitizer in the treatment of human bladder cancer cells. Citation Format: Yu-Chieh Tsai, Tsung-Fan Tuan, Pei-Yin Ho, Wei-Lin Liu, Liang-Yu Chang, Yeong-Shiau Pu, Ann-Lii Cheng, Jason Chia-Hsien Chen. Comparison of afatinib and erlotinib as radiosensitizing agents in bladder cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4429. doi:10.1158/1538-7445.AM2013-4429

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