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NO3• can compete with omnipotent •OH/SO4•– in decomposing aqueous pollutants because of its lengthy lifespan and significant tolerance to background scavengers present in H2O matrices, albeit with moderate oxidizing power. The generation of NO3•, however, is of grand demand due to the need of NO2•/O3, radioactive element, or NaNO3/HNO3 in the presence of highly energized electron/light. This study has pioneered a singular pathway used to radicalize surface NO3– functionalities anchored on polymorphic α-/γ-MnO2 surfaces (α-/γ-MnO2-N), in which Lewis acidic Mn2+/3+ and NO3– served to form •OH via H2O2 dissection and NO3• via radical transfer from •OH to NO3– (•OH → NO3•), respectively. The elementary steps proposed for the •OH → NO3• route could be energetically favorable and marginal except for two stages such as endothermic •OH desorption and exothermic •OH-mediated NO3– radicalization, as verified by EPR spectroscopy experiments and DFT calculations. The Lewis acidic strength of the Mn2+/3+ species innate to α-MnO2-N was the smallest among those inherent to α-/β-/γ-MnO2 and α-/γ-MnO2-N. Hence, α-MnO2-N prompted the rate-determining stage of the •OH → NO3• route (•OH desorption) in the most efficient manner, as also evidenced by the analysis on the energy barrier required to proceed with the •OH → NO3• route. Meanwhile, XANES and in situ DRIFT spectroscopy experiments corroborated that α-MnO2-N provided a larger concentration of surface NO3– species with bi-dentate binding arrays than γ-MnO2-N. Hence, α-MnO2-N could outperform γ-MnO2-N in improving the collision frequency between •OH and NO3– species and in facilitating the exothermic transition of NO3– functionalities to surface NO3• analogues per unit time. These were corroborated by a greater efficiency of α-MnO2-N in decomposing phenol, in addition to scavenging/filtration control runs and DFT calculations. Importantly, supported NO3• species provided 5–7-fold greater efficiency in degrading textile wastewater than conventional •OH and supported SO4•- analogues we discovered previously.

An electro-Fenton system with magnetite coated stainless steel (SUS) mesh as cathode was developed and tested for removing methylene blue in wastewater. For better adhesion between magnetite particles and SUS mesh surface, surface roughening of SUS mesh with FeAl particles was carried out. 850 °C was chosen as the optimized calcination temperature for FeAl treatment. When SUS meshes were coated with magnetite particles and applied as the cathode in an electro-Fenton system, catalytic activation of in situ produced H2O2 was enhanced. And this activation occurred heterogeneously on the surface of magnetite particles on cathode rather than homogeneously with free roaming leached ferrous ions. By coating magnetite particles on SUS meshes, degradation efficiency of methylene blue in neutral conditions was better than that in acidic conditions with bare SUS meshes as cathode in our electro-Fenton system.

BackgroundThe development of personalized neoantigen-based therapeutic cancer vaccines relies on computational algorithm-based pipelines. One of the critical issues in the pipeline is obtaining higher positive predictive value (PPV) performance, i.e., how many are immunogenic when selecting the top 5 to 20 candidate neoepitopes for the vaccination. We attempted to test the PPV of a neoepitope prediction algorithm Neopepsee.MethodsSix breast cancer patients and patient-derived xenografts from three lung cancer patients and their paired peripheral blood samples were subjected to whole-exome and RNA sequencing. Neoantigen was predicted using two different algorithms (Neopepsee and pVACseq). Response of induced memory T cells to neopeptide candidates was evaluated by IFN-γ Enzyme-linked immune absorbent spot (ELISpot) assays of peripheral blood mononuclear cell (PBMC) from three HLA-matched donors. Positive ELISpot response to a candidate peptide in at least 2 of 3 donor PBMC was regarded as an immunogenic response.ResultsNeopepsee predicted 159 HLA-A matched neoepitope candidates out of 898 somatic mutations in nine patients (six breast and three lung cancer patients), whereas pVACseq predicted 84 HLA-A matched candidates. A total of 26 neopeptide candidates overlapped between the two predicted candidate pools. Among the candidates, 28 (20%, 28/ 137) and 15 (20%, 15/ 75) were positive by ELISpot assay, respectively. Among 26 overlapped candidates, 20 could be tested, and 7 of them (35%) were validated by ELISpot. Neopepsee identified at least one neoepitope in 7 of 9 patients (range 0-6), compared to 6 by pVACseq (range 0-5).ConclusionAs suggested by Tumor Neoantigen Selection Alliance (TESLA), our results demonstrate low PPV of individual prediction models as well as the complementary nature of the Neopepsee and pVACseq and may help design neoepitope targeted cancer vaccines. Our data contribute a significant addition to the database of tested neoepitope candidates that can be utilized to further train and improve the prediction algorithms.

Whether estrogen receptor-positive (ER+) breast cancer (BC) can be a target for therapeutic neoepitope vaccination is not clear due to its low mutation burden. We tested the immunogenicity of predicted neoepitopes from exome and RNA-seq data from three ER+/luminal B subtype BC samples using IFN-γ ELISpot assays of HLA-matched donor PBMCs. As a control, three ER- BC and three lung cancers were tested. The ensemble of Neopepsee and pVACseq pipelines predicted 93 neoepitopes from 299 SNVs in three ER+ BCs. Among them, 90 could be tested with ELISpot, and 14 (15.6%) were immunogenic (1, 5, and 10 for each tumor). In three ER- BC samples, 52 neoepitopes were predicted from 271 SNVs, and 12 (25.0%) of 48 tested were immunogenic (2, 4, and 8 for each tumor). Of the three lung cancers, 53 of 72 predicted neoepitope candidates were tested, and 10 of them were immunogenic (18.9%) (0, 1, and 11 for each tumor). These differences were not statistically significant. We conclude that luminal B subtype BCs express neoepitopes and can be a candidate for therapeutic neoepitope vaccination.

Iron sulfides are fascinating catalytic phases because these include S-modified Feδ+ (δ ≤ 2) species functioning as H2O2 activators to form OH used for oxidatively degrading aqueous contaminants (e.g., phenol). As an initial step for locating S-modified metal species (Mδ+) that outperform Feδ+ in catalytic H2O2 cleavage, hexagonal metal sulfides (MS) were synthesized using Mn, Fe, Co, Ni, and Cu to understand electric potential-assisted H2O2 scission kinetics on Mδ+ species. Niδ+ species were found to show the greatest OH productivity among all Mδ+ species studied, mainly resulting from the Lewis acidic nature of Niδ+ species adequate to expedite the liberation of OH species. This was partially evidenced by H2O2 activation/phenol degradation runs on Mδ+ species, wherein initial H2O2 activation rate (-rH2O2,0) or initial phenol degradation rate (-rPHENOL,0) of Niδ+ species was 3–9 times those of the other Mδ+ species. Niδ+ species, therefore, were located in the middle of the volcano-shaped curve plotting -rH2O2,0 (or -rPHENOL,0) versus the type of Mδ+. Kinetic assessment of Mδ+ species under fine-tuned reaction environments also showed that regardless of varying H2O2 concentrations, Mδ+ species were found to retain their -rH2O2,0 values in the absence of electric potentials. Conversely, Mδ+ species could enhance -rPHENOL,0 values at larger electric potentials, where greater energies were likely exerted on Mδ+ species. This indeed corroborated that OH desorption from Mδ+ species was the rate-determining step to direct catalytic H2O2 scission. In addition to heterogeneous catalytic nature of Niδ+ species in fragmenting H2O2, outstanding H2O2 scission ability provided by Niδ+ species could also compensate for their moderate catalytic stability at pH-neutral condition.

Mutations in coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10) can cause amyotrophic lateral sclerosis and frontotemporal dementia (ALS-FTD). However, the underlying mechanisms are unclear. Here, we generate CHCH10S59L-mutant Drosophila melanogaster and HeLa cell lines to model CHCHD10-associated ALS-FTD. The CHCHD10S59L mutation results in cell toxicity in several tissues and mitochondrial defects. CHCHD10S59L independently affects the TDP-43 and PINK1 pathways. CHCHD10S59L expression increases TDP-43 insolubility and mitochondrial translocation. Blocking TDP-43 mitochondrial translocation with a peptide inhibitor reduced CHCHD10S59L-mediated toxicity. While genetic and pharmacological modulation of PINK1 expression and activity of its substrates rescues and mitigates the CHCHD10S59L-induced phenotypes and mitochondrial defects, respectively, in both Drosophila and HeLa cells. Our findings suggest that CHCHD10S59L-induced TDP-43 mitochondrial translocation and chronic activation of PINK1-mediated pathways result in dominant toxicity, providing a mechanistic insight into the CHCHD10 mutations associated with ALS-FTD., Mutations in CHCHD10 can cause amyotrophic lateral sclerosis and frontotemporal dementia. The authors generate mutant Drosophila and HeLa cells to study the underlying mechanisms of CHCHD10S59L -induced degeneration and show it is mediated by TDP-43 and PINK1 pathways.

Enhancing OH productivity via heterogeneous, catalytic H2O2 activation is a long-standing conundrum in H2O purification and thus requires the renovation of conventional reaction systems. The initial step in realizing advanced H2O2 decomposition via heterogeneous catalytic manner is the exploration of the solid capable of efficiently cleaving O O bond inherent to H2O2 and minimizing the loss of catalytic species during vigorous reaction dynamics. While using phenol as a model compound for recalcitrants, this paper highlights the use of Fe3S4/Fe7S8 as a catalyst to enhance OH productivity and thus promote phenol degradation via electro-Fenton reaction over conventional Fe2O3, Fe3O4, and other sulfide analogue (FeS2). Materials’ characterizations and kinetic interpretation of reaction runs under controlled environments served to substantiate the benefits which were provided by Fe3S4/Fe7S8 during the reaction. Fe3S4/Fe7S8 incorporated greater amount of S-modified, surface-exposed Fe2+ sites to cleave H2O2 than FeS2. This improved catalytic consequence of Fe3S4/Fe7S8 (i.e., phenol conversion and initial reaction rate), as also evidenced by control runs detailing H2O2 decomposition in conjunction with tert-butyl alcohol-driven OH scavenging. Filtration control runs as well as recycle runs were also used to verify that Fe3S4/Fe7S8 could heterogeneously catalyze H2O2 scission under the mild, adequate reaction environments, which were realized by the use of low electrical powers and the catalyst immobilized on a cathode.

// Eun Hee Han 1, 2, 6, * , Jin-Young Min 1, 3, * , Shin-Ae Yoo 1 , Sung-Joon Park 1 , Yun-Jeong Choe 1, 2 , Hee Sub Yun 1 , Zee-Won Lee 1 , Sun Woo Jin 4 , Hyung Gyun Kim 4 , Hye Gwang Jeong 4 , Hyun Kyoung Kim 5 , Nam Doo Kim 5 and Young-Ho Chung 1, 3, 6 1 Drug & Disease Target Research Team, Division of Bioconvergence Analysis, Korea Basic Science Institute (KBSI), Cheongju 28119, South Korea 2 Immunotherapy Convergence Research Center, Korean Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, South Korea 3 Graduate School of Analytical Science and Technology (GRAST), Chungnam National University, Daejeon 34134, South Korea 4 Department of Toxicology, College of Pharmacy, Chungnam National University (CNU), Daejeon 34133, South Korea 5 New Drug Development Center, Daugu Gyeoungbuk Medical Innovation Foundation (DGMIF), Daegu 41061, South Korea 6 Department of Bioanalytical Science, Korea University of Science and Technology (UST), Daejeon 34113, South Korea * These authors have contributed equally to this work Correspondence to: Young-Ho Chung, email: chungyh@kbsi.re.kr Keywords: AURKC, protein–protein interaction, IκBα, small-molecule inhibitor, breast cancer Received: December 29, 2016 Accepted: June 05, 2017 Published: June 29, 2017 ABSTRACT The Aurora kinases, Aurora A (AURKA), Aurora B (AURKB), and Aurora C (AURKC), are serine/threonine kinases required for the control of mitosis (AURKA and AURKB) or meiosis (AURKC). Several Aurora kinase inhibitors are being investigated as novel anticancer therapeutics. Recent studies demonstrated that AURKC activation contributes to breast cancer cell transformation. Therefore, AURKC is both a promising marker and therapeutic target for breast cancer; however, its signaling network has not been fully characterized. Using translocation-based cellular assays, we identified IκBα as a binding partner of AURKC, and found that AURKC phosphorylates IκBα at Ser32, thereby activating it. In silico modeling and computational analyses revealed a small-molecule inhibitor (AKCI) that blocked the AURKC–IκBα interaction and exerted antitumor activity in MDA-MB-231 breast cancer cells. Specifically, AKCI induced G2/M cell-cycle arrest through modulation of the p53/p21/CDC2/cyclin B1 pathways. In addition, the drug significantly inhibited MDA-MB-231 cell migration and invasion, as well as decreasing colony formation and tumor growth. Via its interaction with IκBα, AURKC indirectly induced NF-κB activation; accordingly, AKCI decreased PMA-induced activation of NF-κB. Thus, the small-molecule inhibitor AKCI represents a first step towards developing targeted inhibitors of AURKC protein binding, which may lead to further advances in the treatment of breast cancer.

Mutations in coiled-coil-helix-coiled-coil-helix domain containing 10 (CHCHD10) are a genetic cause of amyotrophic lateral sclerosis and/or frontotemporal dementia (ALS-FTD). To elucidate how mutations in CHCHD10 induce disease, we generated a Drosophila melanogaster model of CHCHD10-mediated ALS-FTD. Expression of CHCHD10S59L in Drosophila caused gain-of-function toxicity in eyes, motor neurons, and muscles, in addition to mitochondrial defects in flies and HeLa cells. TDP-43 and PINK1 formed two axes, driving the mutant-dependent phenotypes. CHCHD10S59L expression increased TDP-43 insolubility and mitochondrial translocation. Blocking mitochondrial translocation with a peptide inhibitor reduced CHCHD10S59L-mediated toxicity. PINK1 knockdown rescued CHCHD10S59L-mediated phenotypes in Drosophila and HeLa cells. The two PINK1 substrates mitofusin and mitofilin were genetic modifiers of this phenotype. Mitofusin agonists reversed the CHCHD10S59L-induced phenotypes in Drosophila and HeLa cells and increased ATP production in Drosophila expressing C9orf72 with expanded GGGGCC repeats. Two peptides inhibitors of PINK1 mitigated the mitochondrial defects introduced by CHCHD10S59L expression. These findings indicate that TDP-43 mitochondrial translocation and chronic activation of PINK1-mediated pathways by CHCHD10S59L generate dominant toxicity. Therefore, inhibiting PINK1 activity may provide a therapeutic strategy for CHCHD10-associated disease.One Sentence SummaryInhibition of TDP-43 mitochondrial translocation or PINK1 kinase activity mitigates CHCHD10S59L-mediated mitochondrial toxicity.

Generation of SO4 − anchored on metal oxides via radical transfer from •OH to surface SO42− functionality (•OH → SO4 −) is singular, unraveled recently, and promising to decompose aqueous refractory contaminants. The core in furthering supported SO4 − production is to reduce the energy required to accelerate the rate-determining step of the •OH → SO4 − (•OH desorption), while increasing the collision frequency between the •OH precursors (H2O2) and H2O2 activators (Lewis acidic metals) or between SO42−-attacking radicals (•OH) and supported SO4 − precursors (SO42−). Herein, Mn-substituted Fe3O4 oxo-spinels (MnXFe3-XO4; MnX) served as reservoirs to accommodate the Lewis acidic Fe/Mn and SO42−, whose properties were tailored by altering the metal compositions (X). The production of supported SO4 − via the •OH → SO4 − was of high tangibility, as confirmed by their electron paramagnetic resonance spectra coupled with those simulated. A concave trend was observed in the plot of the Lewis acidic strength of Fe/Mn versus X of MnX with the minimum at X ~ 1.5. Hence, Mn1.5 could expedite •OH liberation from the surface most proficiently and therefore exhibited the greatest initial H2O2 scission rate, as corroborated by its lowest energy barrier needed for activating the •OH → SO4 −. Meanwhile, a volcano-shaped trend was found in the plot of SO42− concentration versus X of MnX (other than Mn3). This could tentatively increase the collision frequency between •OH and SO42− on the surface of Mn1.5, as partially substantiated by its second largest pre-factor among the catalysts. Therefore, Mn1.5 exhibited the highest phenol consumption rate (-rPHENOL, 0) among the catalysts, which was ~ 20-fold larger than those for SO42−-modified Fe2O3 and NiO, which we reported previously. Mn1.5 also outperformed other catalysts in recycling phenol degradation, fragmenting another pollutant (aniline), and mineralizing phenol/aniline.

Exposing SO42− functionalities on Fe2O3 to an electric environment can produce supported SO4 − species via radical interconversion of OH ↔ SO4 −, which can degrade aqueous contaminants (phenol). This methodology is unique, has substantial potential, yet, is underexplored regarding how to mechanistically account for or to further accelerate radical transfer of OH → SO4 −. Herein, NiO serves as a novel platform to accommodate SO42− functionalities, whereas the resulting SO42−-modified NiO (NiO (S)) was kinetically evaluated or subjected to density functional theory (DFT) calculations to clarify the benefits of surface Niδ+ (δ ≤ 2), SO42−, or OH → SO4 −. NiO (S) was verified to contain abundant surface-labile O, facilitate electron transfer, and thus could increase H2O2 productivity. The Lewis acidity of Niδ+ active to cleave H2O2 was also improved by SO42−, as evidenced by in situ diffuse reflectance Infrared Fourier transform spectra and Bader charge calculations. This helped enhance OH productivity of NiO (S) over NiO, whose energetics were computed and validated that OH production was directed by OH desorption from Niδ+. Furthermore, electron paramagnetic resonance spectroscopy and DFT calculations also substantiated NiO (S) was energetically favorable toward radical transfer from OH to SO4 −, in which Ni bound to SO42− was identified to spur the formation of supported SO4 − via electron exchange with SO42−/ OH. In conjunction with mechanistic elucidation using theoretical calculations, kinetic assessment of H2O2 scission and phenol decomposition runs under various electric potentials corroborated OH desorption was the rate-determining step of overall OH → SO4 − pathway. Importantly, NiO (S) synthesized at 400 °C could enhance the efficiency, reusability, and stability in decomposing phenol over NiO/Fe2O3 functionalized with SO42− at 300, 500, or 600 °C.

Nutlin-3 which occupies the p53 binding pocket in HDM2, has been reported to activate apoptosis through both the transcriptional activity-dependent and -independent programs of p53. Transcription-independent apoptosis by nutlin-3 is triggered by p53 which is translocated to mitochondria. However, we previously demonstrated that the nutlin-3-induced mitochondrial translocation of p53 stimulates ERK1/2 activation, an anti-apoptosis signal, via mitochondrial ROS generation. We report on how nutlin-3-stimulated ERK1/2 activity inhibits p53-induced apoptosis. Among the anti-apoptotic BCL2 family proteins, BCL2A1 expression was increased by nutlin-3 at both the mRNA and protein levels, and this increase was prevented by the inhibition of ERK1/2. TEMPO, a ROS scavenger, and PFT-μ , a blocker of the mitochondrial translocation of p53, also inhibited BCL2A1 expression as well as ERK1/2 phosphorylation. In addition, nutlin-3 stimulated phosphorylation of ELK1, which was prevented by all compounds that inhibited nutlin-3-induced ERK1/2 such as U0126, PFT-μ and TEMPO. Moreover, an increase in BCL2A1 expression was weakened by the knockdown of ELK1. Finally, nutlin-3-induced apoptosis was found to be potentiated by the knockdown of BCL2A1, as demonstrated by an increase of in hypo-diploidic cells and Annexin V-positive cells. Parallel to the increase in apoptotic cells, the knockdown of BCL2A1 augmented the cleavage of poly(ADP-ribose) polymerase-1. It is noteworthy that the augmented levels of apoptosis induced by the knockdown of BCL2A1 were comparable to those of apoptosis induced by U0126. Collectively, these results suggest that nutlin-3-activated ERK1/2 may stimulate the transcription of BCL2A1 via the activation of ELK1, and BCL2A1 expression may contribute to the inhibitory effect of ERK1/2 on nutlin-3-induced apoptosis, thereby constituting a negative feedback loop of p53-induced apoptosis.

Iron oxides are considered as ubiquitous yet valuable carriers of surface Fe2+ activators to excite H2O2, which results in the production of •OH used to decompose refractory contaminants present in H2O. To exploit catalytic nature provided by surface Fe2+ species, Fe2+ species can experience their modification by S to form S-doped iron oxide, Fe3S4, and Fe7S8, etc.1,2 For instance, we have synthesized Fe2O3 and have functionalized its surface using S species.2 The resulting S-doped Fe2O3 has manifested itself as an intriguing catalytic solid for H2O2 activation. This was because of its several benefits including 1) the incorporation of large amount of surface Fe2+ species used to cleave H2O2 via heterogeneous catalysis, 2) meso-porosity allowing for improved accessibility of H2O2 into surface Fe2+ species, and 3) chemical rigidity leading to minimized loss of Fe2+ species during H2O2 scission reactions.2 Nonetheless, surface of S-doped Fe2O3 isn't disclosed in two particular aspects of 1) H2O2 scission mechanism on S-modified Fe2+ species and 2) their catalytic functions. To answer these questions, we strategized the functionalization of Fe2O3 (pristine) surface with SO4 2- species at 300-600 °C to generate S300-S600 and investigated their surface properties using chemi-sorption/spectroscopy techniques. We then performed reaction runs under regulated environments, while using phenol as a model compound of recalcitrant compounds. Apparently, phenol degradation was directed by the characters of SO4 2- functionalities dispersed on Fe2O3 surface, whose features were markedly varied upon the change in the temperatures utilized to modify Fe2O3 surface with SO4 2- functionalities. 500 °C was required to degrade phenol in the most efficient manner among all SO4 2- functionalization temperatures studied, as showcased below. (XPHENOL and kAPP denote conversion of phenol and reaction rate constant, respectively.) In this presentation, we will address the answers to pivotal questions detailed above. In addition, we will also highlight our efforts for clarifying catalytic roles of surface SO4 2- functionalities via a series of kinetic assessment. References [1] J. Kim and co-workers, Appl. Catal. B 233 (2018) 272. [2] S. H. Kim and co-workers, Appl. Catal. B 184 (2016) 132. Figure 1

A recent study reported that p53 can induce HO-1 by directly binding to the putative p53 responsive element in the HO-1 promoter. In this study, we report that nutlin-3, a small molecule antagonist of HDM2, induces the transcription of HO-1 in a transcription-independent manner of p53. Nutlin-3 induced HO-1 expression at the level of transcription in human cancer cells such as U2OS and RKO cells. This induction of HO-1 did not occur in SAOS cells in which p53 was mutated and was prevented by knocking down the p53 protein using p53 siRNA transfection, but not by PFT-α, an inhibitor of the transcriptional activity of p53. Accompanying HO-1 expression, nutlin-3 stimulated the accumulation of ROS and the phosphorylation of MAPKs such as JNK, p38 MAPK and ERK1/2. Nutlin-3-induced HO-1 expression was suppressed by TEMPO, a ROS scavenger, and chemical inhibitors of JNK and p38 MAPK but not ERK1/2. In addition, nutlin‑3-induced phosphorylation of JNK but not p38 MAPK was inhibited by TEMPO. Notably, the levels of nutlin-3-induced ROS were correlated with the mitochondrial translocation of p53 and this induction was prevented by PFT-μ, an inhibitor of the mitochondrial translocation of p53. Consistent with the effect of the ROS scavenger and MAPK inhibitors, PFT-μ reduced HO-1 expression and the phosphorylation of JNK induced by nutlin-3. In the experiments of analyzing cell death, the knockdown of HO-1 augmented nutlin-3-induced apoptosis. Collectively, these results suggest that nutlin-3 induces HO-1 expression via the activation of both JNK which is dependent on ROS generated by p53 translocated to the mitochondria and p38 MAPK which appears to be stimulated by a ROS-independent mechanism, and this HO-1 induction may inhibit nutlin-3-induced apoptosis, constituting a negative feedback loop of p53-induced apoptosis.

Tight regulation of autophagy is critical for the fate of pancreatic β cells. The autophagy protein ATG5 is essential for the formation of autophagosomes by promoting the lipidation of microtubule-associated protein LC3 (light chain 3). However, little is known about the mechanisms that regulate ATG5 expression levels. In this study, we investigated the regulation of ATG5 expression by HuD. The association of HuD with ATG5 mRNA was analyzed by ribonucleoprotein complex immunoprecipitation and biotin pulldown assays. HuD expression levels in pancreatic β cells were knocked down via siRNA, elevated by overexpression of a HuD-expressing plasmid. The expression levels of HuD, ATG5, LC3, and β-actin were determined by Western blot and quantitative RT-PCR analysis. Autophagosome formation was assessed by fluorescence microscopy in GFP-LC3-expressing cells and in pancreatic tissues from WT and HuD-null mice. We identified ATG5 mRNA as a post-transcriptional target of the mammalian RNA-binding protein HuD in pancreatic β cells. HuD associated with the 3′-UTR of the ATG5 mRNA. Modulating HuD abundance did not alter ATG5 mRNA levels, but HuD silencing decreased ATG5 mRNA translation, and, conversely, HuD overexpression enhanced ATG5 mRNA translation. Through its effect on ATG5, HuD contributed to the lipidation of LC3 and the formation of LC3-positive autophagosomes. In keeping with this regulatory paradigm, HuD-null mice displayed lower ATG5 and LC3 levels in pancreatic β cells. Our results reveal HuD to be an inducer of ATG5 expression and hence a critical regulator of autophagosome formation in pancreatic β cells.

Nutlin-3, a human double minute 2 (HDM2) antagonist, induces cell cycle arrest or apoptosis by upregulating p53 in cancer cells. WT1, the product of Wilms' tumor gene 1, has been shown to interact with p53, but the effect of WT1 on nutlin-3-induced apoptosis has yet to be examined. To address this issue, we analyzed the inhibitory effect of nutlin-3 on cell growth as a function of Wt1 expression status using a Wt1-inducible U2OS cell line. In the absence of Wt1 expression, nutlin-3 induced cell cycle arrest with marginal cytotoxicity. Furthermore, upon Wt1 expression, nutlin-3 exerted a marked degree of cell death, as evidenced by the accumulation of hypo-diploid cells and LDH release. During cell death induction, cytochrome c was released into the cytosol, and caspase-9 and -3 were activated, suggesting that an intrinsic apoptotic pathway may be involved in this cell death. Consistent with this, z-VAD-Fmk, a pan-caspase inhibitor and the overexpression of BCL-XL attenuated the cell death. Nutlin-3 caused an increase in the mRNA levels of both BCL-XL and BAK, as well as their corresponding protein levels in mitochondria. In the presence of Wt1, nutlin-3-induced BCL-XL expression was attenuated while the expression of nutlin-3-induced BAK was potentiated. Collectively, these results suggest that WT1 potentiates nutlin-3-induced apoptosis by downregulating the expression of BCL-XL while upregulating that of BAK, which leads to the activation of an intrinsic apoptotic pathway.

Anthocyanins (ATCs) have been reported to induce apoptosis in various types of cancer cells, stimulating the development of ATCs as a cancer chemotherapeutic or chemopreventive agent. It was recently reported that ATCs can induce autophagy, however, the mechanism for this remains unclear. In the present report, we carried out mechanistic studies of the mechanism involved in ATC-induced autophagy using ATCs extracted from black soybeans (cv. Cheongja 3, Glycine max L.). ATCs clearly induced hallmarks of autophagy, including LC3 puncta formation and the conversion of LC3-I to LC3-II in U2OS human osteosarcoma cells. The induction of autophagy was accompanied by the phosphorylation of multiple protein kinases including extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK), protein kinase B (AKT) and adenosyl mono-phosphate-dependent protein kinase (AMPK). While chemical inhibitors against ERK1/2, p38 MAPK, JNK and AKT failed to inhibit ATC-induced autophagy, the suppression of AMPK by compound C (CC) as well as siRNA against AMPK reduced ATC-induced autophagy. The treatment of ATCs resulted in a decrease in intracellular ATP contents and the activation of AMPK by AICAR treatment also induced autophagy. It is noteworthy that the reduction of autophagy via the inhibition of AMPK resulted in enhanced apoptosis in ATC-treated cells. In addition, siRNA against forkhead box O3A (FOXO3a), a downstream target of AMPK, suppressed ATC-induced autophagy and p27KIP1 siRNA increased apoptosis in ATC-treated cells. Collectively, it can be concluded that ATCs induce autophagy in U2OS cells via activation of the AMPK-FOXO3a pathway and protect cells from ATC-induced apoptosis via the AMPK-p27KIP1 pathway. These results also suggest that autophagy-modulating agents could contribute to the efficient development of ATCs as anticancer therapy.

【3-Deazaadenosine (DZA), a potent inhibitor of S-adenosylhomocysteine hydrolase, was previously proposed to induce intrinsic apoptosis in human leukemic cells. In the present study, we analyzed the mechanism underlying the DZA-induced intrinsic apoptotic pathway. DZA activated typical caspase-dependent apoptosis in HL-60 cells, as demonstrated by an accumulation of hypo-diploidic cells, the processing of multiple procaspases and an inhibitory effect of z-VAD-Fmk on this cell death. During DZA-induced apoptosis, cytochrome c (cyt c) was released into the cytosol. This was neither prevented by z-VAD-Fmk and nor was it associated with the dissipation of mitochondrial membrane potential ( ${\Delta}{\Psi}_m$ ). Prior to the release of cyt c, BAX was translocated from the cytosol to mitochondria and underwent oligomerization. Finally, the overexpression of BCL-XL protected HL-60 cells from apoptosis by blocking both the cyt c release and BAX oligomerization. Collectively, these findings suggest that DZA may activate intrinsic apoptosis by stimulating BAX activation and thereby the release of cyt c.】