Abstract. Tremella fuciformis polysaccharide (TFPS), which is the extract of Tremella fuciformis Berk, has previously been demonstrated to exhibit potent anti-oxidative, anti-inflammatory and anti-aging effects. However, the mechanisms underlying these protective and therapeutic effects remain to be elucidated. The aim of the present study was to investigate the protective effects of TFPS on hydrogen peroxide-induced injury of human skin fibroblasts and to elucidate the aforementioned underlying mechanisms. A hydrogen peroxide-induced human skin fibroblast injury model was firstly established. MTT and reactive oxygen species (ROS) production assays, in addition to terminal deoxynucleotidyl transferase dUTP nick end labeling, reverse transcription-quantitative polymerase chain reaction and western blotting, were performed to investigate the protective effects of TFPS. Hydrogen peroxide decreased human skin fibroblast viability with a concurrent increase in ROS generation and cell apoptosis. Treatment with 0-400 µg/ml TFPS alone for up to 48 h did not result in alteration in cell viability. Notably, TFPS pre-treatment reduced oxidative stress and cell apoptosis in hydrogen peroxide-treated skin fibroblasts. In addition, there was profound inhibition of p16, p21, p53 and caspase-3 expression, and activation of extracellular-signal regulated kinase and Akt serine/threonine kinase 1, following TFPS pre-treatment. Furthermore, it was revealed that TFPS additionally protected fibroblasts via the upregulation of SIRT1 expression, and this was abrogated by the SIRT1 inhibitor niacinamide. These results indicated that TFPS alleviated hydrogen peroxide-induced oxidative stress and apoptosis in skin fibroblasts via upregulation of SIRT1 expression, indicating that TFPS may act as a potential therapeutic agent for oxidative-stress-associated skin diseases and aging. IntroductionOxidative stress induced by free radicals, which are produced in response to redox reactions, radiation and chemical reactions, can cause DNA and protein damage. Such stress is associated with the development of many diseases, such as atherosclerosis, diabetes mellitus, articular gout, and cancer (1,2). Hydrogen peroxide (H 2 O 2 ) is one of type of reactive oxygen species (ROS) produced in normal cells during cell respiration and metabolism (3). However, many studies have indicated that a high concentration of H 2 O 2 , present under pathological conditions, may induce various human degenerative diseases and aging. Furthermore, H 2 O 2 also interacts with intracellular ions such as iron and copper, leading to a chain reaction that produces more reactive radicals and amplifies the damage, thereby causing DNA and protein damage (4). Therefore, antioxidants are very important for the treatment of oxidative-stress-related diseases and aging.Antioxidants in food, including vitamin C, polyphenols, tocopherols and f lavonoids, may prevent free-radical-induced cell damage (5). They also may attenuate oxidative-stress-induced inflammatory reactions and apopto...

Background Adherent junction associated protein 1 (AJAP1), a typical molecule of adherent junctions, has been found to be a tumor suppressor in many cancer types. Aberrant activation of β-catenin has been demonstrated to be associated with malignant biological properties of tumors including breast cancer. This study aimed to investigate the function and mechanism of AJAP1-mediated β-catenin activity of breast cancer lines in vitro and in breast cancer patients. Methods AJAP1 and β-catenin expressions in breast cancer tissues and cell lines were detected by immunohistochemistry, western blotting and qRT-PCR. The EGF/EGFR axis-mediated AJAP1 attenuated β-catenin nuclear location was measured by western blotting, immunofluorescence assay, co-immunoprecipitation, luciferase assay and ubiquitination assays. Furthermore, the function of AJAP1 and β-catenin regulated breast cancer progression was explored both in vivo and in vitro . Results It was found that AJAP1 had a high negative correlation with β-catenin nuclear expression and was a novel tumor suppressor in breast cancer. AJAP1 loss can mediate β-catenin accumulated in cytoplasm and then transferred it to the nucleus, activating β-catenin transcriptional activity and downstream genes. Additionally, β-catenin can reverse the invasion, proliferation ability and tumorigenicity of the depletion of AJAP1 caused both in vivo and in vitro. Besides, EGF/EGFR also involved in the process of AJAP1-depiction induced β-catenin transactivation to the nucleus. More importantly, EGFR depletion/AJAP1 knocked down promoted the progression of breast cancer by regulating the activity of β-catenin nuclear transactivation. Conclusion This study demonstrated that AJAP1 acted as a putative tumor suppressor while β-catenin nuclear localization positively fed back on EGF/EGFR-attenuated AJAP1 expression in breast cancer, which might be beneficial to develop new therapeutic targets for decreasing nuclear β-catenin-mediated malignancy in breast cancer. Electronic supplementary material The online version of this article (10.1186/s13046-019-1252-6) contains supplementary material, which is available to authorized users.

Cisplatin resistance remains a major obstacle to effective chemotherapies for non-small cell lung cancer (NSCLC). Chaperonin containing TCP1 subunit 3 (CCT3) has been extensively investigated in various cancers, but not in the context of drug resistance. In the present study, we aimed to investigate the role of CCT3 in cisplatin resistance of lung adenocarcinoma (LUAD) cells. By surveying the Gene Expression Profiling Interactive Analysis (GEPIA) website, we found CCT3 expression to be up-regulated in NSCLCs, which correlated with the poor prognosis of LUAD patients. Furthermore, both mRNA and protein levels of CCT3 were upregulated in the cisplatinresistant A549/DDP cells compared to the cisplatin-sensitive A549 cells. Importantly, upon cisplatin treatment, short hairpin RNA (shRNA)-mediated CCT3 knockdown significantly inhibited the proliferation, invasion and migration of A549/DDP cells, and induced significant G2/M cell cycle arrest and apoptosis in A549/DDP cells. Moreover, CCT3 knockdown significantly weakened the tumorigenicity of the cisplatin-treated A549/DDP cells in vitro and in vivo. Finally, CCT3 knockdown re-sensitized A549/DDP cells to cisplatin through inhibiting the Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) pathway. In conclusion, our results demonstrated that CCT3 could promote cisplatin resistance of LUAD cells via activating the JAK2/ STAT3 pathway, indicating that CCT3 may be a novel molecular target for overcoming cisplatin resistance in LUAD patients.

The first catalytic asymmetric construction of chiral dihydrobenzo[ e]indole scaffolds has been established in a highly diastereo- and enantioselective mode (30 examples, up to 99% yield, >95:5 dr, >99% ee), which makes use of chiral phosphoric acid-catalyzed [3 + 2] cycloannulations of azonaphthalene derivatives with 3-vinylindoles. This reaction also represents the first catalytic asymmetric cycloannulation of azonaphthalene derivatives with alkenes, which will not only provide a useful method for constructing enantioenriched dihydrobenzo[ e]indole scaffolds but also advance the chemistry of catalytic asymmetric reactions of azonaphthalene derivatives.

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