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Objective·To investigate the effect of F-box only protein 38 (FBXO38) on the ocular melanoma proliferation and the potential regulatory pathway.Methods·Human skin cutaneous melanoma A375 and human uveal melanoma OMM2.3 cell lines with FBXO38 knockdown and overexpression were constructed by FBXO38 short hairpin RNA (shRNA) and FBXO38 overexpression plasmids respectively. Knockdown and overexpression efficiency of FBXO38 at transcription and protein levels were verified by using quantitative real-time PCR (qRT-PCR) and Western blotting. The effects of FBXO38 on melanoma cell proliferation were detected through clonal formation assay, BrdU immunofluorescence staining and CCK8 cell proliferation assay. By using The Cancer Genome Atlas (TCGA) database, differentially expressed genes were analyzed in the high and low expression groups of FBXO38. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment was performed to reveal the signaling pathways associated with FBXO38. CCK8 cell proliferation assay was used to detect the inhibition rates of the signaling pathway inhibitors on cells with different FBXO38 expression levels. qRT-PCR and Western blotting were used to detect whether the signaling pathway was activated after knocking down FBXO38.Results·qRT-PCR and Western blotting verified that mRNA and protein expression levels of FBXO38 in FBXO38 knockdown A375 and OMM2.3 cell lines decreased compared with the control group, while the expression levels of FBXO38 in the overexpression cell lines increased compared with wild type group (P

Objective·To analyze the full-length protein structure of human-derived lysine acetyltransferase 7 (KAT7) using cryo-electron microscopy (Cryo-EM) and to obtain the profile information of human-derived KAT7.Methods·The recombinant protein expression plasmid pGEX-4T1-GST-KAT7 was constructed by using the pGEX-4T1 vector and the full-length gene of human-derived KAT7, and the KAT7 protein was expressed in the prokaryotic protein expression system BL21 (DE3). The GST-KAT7 recombinant protein was obtained by using GST affinity chromatography. After removing the GST protein tag with TEV protease, KAT7 was further isolated and purified by HiLoad 16/600 Superdex 75 pg volume exclusion chromatography. The obtained protein samples were identified by Western blotting, and the samples were screened. The protein morphology was observed under negative-stain electron microscopy, and data were collected by using Cryo-EM. The protein particles were selected and the spatial structure of the full-length KAT7 was analyzed with the Cryo-EM analysis software CryoSparc. The MYST structural domain model (5GK9) in the Protein Data Bank (PDB) and AlphaFold prediction model of KAT7 were matched with the generated structural model by UCSF Chimera software.Results·The full-length protein of human-derived KAT7 was successfully purified by affinity chromatography, and high purity KAT7 was obtained by volume exclusion chromatography. After identifying KAT7 by Western blotting, the spatial structure of KAT7 full-length protein was initially resolved by Cryo-EM and single-particle reconstruction techniques, and a preliminary three-dimensional structure model with a resolution of about 10 Å was obtained by three-dimensional optimization. The spatial structure of KAT7 full-length protein was irregular and semi-loop-shaped, and the existing MYST domain model (PDB: 5GK9) can be matched into the C-terminal part of the KAT7 full-length model. The adjusted AlphaFold prediction model can also match the KAT7 full-length structure model.Conclusion·A preliminary analysis of the spatial structure model of full-length protein of human-derived KAT7 is performed by using Cryo-EM.

Objective·To investigate the role of RBX1 (ring-box protein 1) in the regulation of immune-related genes in uveal melanoma (UVM) tumor cells.Methods·The Cancer Genome Atlas (TCGA) was searched to analyze the expression levels of RBX1 in tumors and the correlation with clinical stages and survival prognosis. RBX1 was transiently knocked down in the UVM cell lines, i.e., 92.1, OMM2.3 and MEL290 by using small interfering RNAs (siRNAs) targeting RBX1. RNA sequencing was performed on the 92.1 cells with transient knockdown of RBX1, and the differentially expressed genes between the siRBX1-transfected cells and control cells were analyzed by gene set enrichment analysis (GSEA) to investigate the relationship between RBX1 and tumor immune-related genes. Based on the results of the analysis, signal transducer and activator of transcription 1 (STAT1) and its downstream CXC chemokine ligand 9 (CXCL9) and CXCL10 mRNA expression levels were detected by real-time fluorescence quantitative PCR (qPCR) in 92.1, OMM2.3 and MEL290 cells with transient knockdown of RBX1, respectively. The protein expression levels of STAT1 and p-STAT1 in 92.1 cells were detected by Western blotting. The cell lines OMM2.3 and MEL290, in which RBX1 was transiently knocked down, were treated with 5 nmol/L or 10 nmol/L STAT1 inhibitor fludarabine for 48 h, and the mRNA expression levels of CXCL9 and CXCL10 were detected by qPCR.Results·TCGA database analysis showed that RBX1 was highly expressed in a variety of tumors compared to the normal tissues, particularly in adrenocortical carcinoma and UVM. In addition, the patients with late stage of these two kinds of tumors had higher expression level of RBX1, and the patients with higher expression level of RBX1 had shorter overall survival time (P

Investigation of natural products is an attractive strategy to identify novel compounds for cancer prevention and treatment. Numerous studies have shown the efficacy and safety of natural products, and they have been widely used as alternative treatments for a wide range of illnesses, including cancers. However, it remains unknown whether natural products affect homologous recombination (HR)-mediated DNA repair and whether these compounds can be used as sensitizers with minimal toxicity to improve patients' responses to radiation therapy, a mainstay of treatment for many human cancers. In this study, in order to systematically identify natural products with an inhibitory effect on HR repair, we developed a high-throughput image-based HR repair screening assay and screened a chemical library containing natural products. Among the most interesting of the candidate compounds identified from the screen was β-thujaplicin, a bioactive compound isolated from the heart wood of plants in the Cupressaceae family, can significantly inhibit HR repair. We further demonstrated that β-thujaplicin inhibits HR repair by reducing the recruitment of a key HR repair protein, Rad51, to DNA double-strand breaks. More importantly, our results showed that β-thujaplicin can radiosensitize cancer cells. Additionally, β-thujaplicin sensitizes cancer cells to PARP inhibitor in different cancer cell lines. Collectively, our findings for the first time identify natural compound β-thujaplicin, which has a good biosafety profile, as a novel HR repair inhibitor with great potential to be translated into clinical applications as a sensitizer to DNA-damage-inducing treatment such as radiation and PARP inhibitor. In addition, our study provides proof of the principle that our robust high-throughput functional HR repair assay can be used for a large-scale screening system to identify novel natural products that regulate DNA repair and cellular responses to DNA damage-inducing treatments such as radiation therapy.

ARID1A, a component of the chromatin remodeling complex SWI/SNF, is an evolutionarily conserved complex that uses the energy of adenosine triphosphate hydrolysis to remodel chromatin structure and functions as a master regulator of gene transcription. Recent genomic studies have revealed that ARID1A is one of the most frequently mutated genes in human cancers. However, therapeutic approaches that selectively target ARID1A-mutant tumors are not yet clinically available. Our previous study showed that ARID1A facilitates chromatin response and cell cycle checkpoint activation after DNA damage. Therefore, an ARID1A deficiency may result in therapeutic vulnerabilities in cell cycle modulators. The goals of our study were to develop a novel screening approach, based on fluorescent ubiquitination-based cell cycle indicators (FUCCI), and to identify chemical agents that can selectively modulate the cell cycle transition in ARID1A-deficient cancer cells. Using this high-throughput assay, we screened 2643 compounds and identified six potential chemical modulators that can selectively modulate the cell cycle in ARID1A-deficient cells; these agents may be useful for developing new therapeutics for ARID1A-mutant tumors. In summary, our study demonstrates that FUCCI cell-based high-content screening is a powerful and effective approach for identifying cell cycle modulators and can be applied to multigenotypic screening for targeted cancer therapeutics.

Rechargeable lithium–sulfur (Li–S) batteries, featuring high energy density, low cost, and environmental friendliness, have been dubbed as one of the most promising candidates to replace current commercial rechargeable Li‐ion batteries. However, their practical deployment has long been plagued by the infamous "shuttle effect" of soluble Li polysulfides (LiPSs) and the rampant growth of Li dendrites. Therefore, it is important to specifically elucidate the solvation structure in the Li–S system and systematically summarize the feasibility strategies that can simultaneously suppress the shuttle effect and the growth of Li dendrites for practical applications. This review attempts to achieve this goal. In this review, we first introduce the importance of developing Li–S batteries and highlight the key challenges. Then, we revisit the working principles of Li–S batteries and underscore the fundamental understanding of LiPSs. Next, we summarize some representative characterization techniques and theoretical calculations applied to characterize the solvation structure of LiPSs. Afterward, we overview feasible designing strategies that can simultaneously suppress the shuttle effect of soluble LiPSs and the growth of Li dendrites. Finally, we conclude and propose personal insights and perspectives on the future development of Li–S batteries. We envisage that this timely review can provide some inspiration to build better Li–S batteries for promoting practical applications. [ABSTRACT FROM AUTHOR]

It is significant to develop low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) via electrochemical water splitting. Herein, we constructed P-doped NiCo2S4 nanowire arrays on carbon fiber paper (NiCo2S4−xPx/CFP) as a HER electrocatalyst in both acidic and alkaline media. Benefitting from P doping into NiCo2S4, the as-prepared NiCo2S4−xPx/CFP exhibits low HER overpotentials of 80 and 132 mV in acidic and alkaline media at a cathodic current density of 10 mA cm−2, respectively, which are far superior to counterparts of NiCo2S4 nanowire arrays on the carbon fiber paper (NiCo2S4/CFP). Meanwhile, the NiCo2S4−xPx/CFP presents excellent HER stability of 20 hours in acidic and alkaline media. From the results of density functional theory calculations, P doping can not only optimize the hydrogen adsorption energetics on each kind of atomic site of catalysts, but also strengthen the H2O molecule binding ability on the catalyst surface for the alkaline HER and favor kinetics of hydrogen adsorption and H2 formation on the catalyst surface for the acidic HER, eventually improving overall HER performances. The investigation of the HER mechanism modulated by P doping in our work offers novel inspiration to develop highly efficient ternary metal sulfides for the HER. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn‐δ‐MnO2 batteries, featuring high safety, high theoretical capacity, and low cost, have emerged as promising candidates for grid‐scale energy storage systems. Nevertheless, the severe cathodic structural degradation greatly hinders its further commercial application. Herein, a facile coupling engineering strategy, employing the Ti3C2Tx MXene skeleton coupled with electrolyte additive K2SO4 to reinforce the structural stability of the δ‐MnO2 cathode is proposed. Notably, the designed K‐birnessite δ‐MnO2/Ti3C2Tx composite cathode (KMO/Ti3C2) coupled with K2SO4 electrolyte additive exhibits unique electrode/electrolyte synergistic effects on inhibiting the cathodic structural collapse and promoting the Mn2+ electrodeposition. Meanwhile, the plating/stripping reversibility of the Zn anode is considerably improved by manipulating the formation of zinc dendrites. Consequently, the Zn//KMO/Ti3C2 battery achieves the remarkable specific capacity of 502.2 mAh g−1 at 0.3 A g−1 and 371.1 mAh g−1 at 2.0 A g−1. Furthermore, after 9500 cycles at a high current density of 10 A g−1, the capacity retention reaches 93.3%. Besides, the dendrite‐free Zn anode delivers excellent cycling stability (over 4800 h at 0.2 mA cm−2) and high coulombic efficiency (99.9% after 2300 cycles). The synergistic effect of electrode/electrolyte provides distinctive insights into the structural stabilization of the manganese‐based cathode to improve the overall performance of batteries. [ABSTRACT FROM AUTHOR]

ARID1A, a component of the chromatin-remodeling complex SWI/SNF, is one of the most frequently mutated genes in human cancer. We sought to develop rational combination therapy to potentiate the efficacy of immune checkpoint blockade in ARID1A-deficient tumors. In a proteomic analysis of a data set from The Cancer Genomic Atlas, we found enhanced expression of Chk2, a DNA damage checkpoint kinase, in ARID1A-mutated/deficient tumors. Surprisingly, we found that ARID1A targets the nonchromatin substrate Chk2 for ubiquitination. Loss of ARID1A increased the Chk2 level through modulating autoubiquitination of the E3-ligase RNF8 and thereby reducing RNF8-mediated Chk2 degradation. Inhibition of the ATM/Chk2 DNA damage checkpoint axis led to replication stress and accumulation of cytosolic DNA, which subsequently activated the DNA sensor STING-mediated innate immune response in ARID1A-deficient tumors. As expected, tumors with mutation or low expression of both ARID1A and ATM/Chk2 exhibited increased tumor-infiltrating lymphocytes and were associated with longer patient survival. Notably, an ATM inhibitor selectively potentiated the efficacy of immune checkpoint blockade in ARID1A-depleted tumors but not in WT tumors. Together, these results suggest that ARID1A's targeting of the nonchromatin substrate Chk2 for ubiquitination makes it possible to selectively modulate cancer cell-intrinsic innate immunity to enhance the antitumor activity of immune checkpoint blockade., Introduction ARID1A is a component of the evolutionarily conserved chromatin-remodeling complex SWI/SNF, which uses the energy from ATP hydrolysis to relax condensed chromatin structure (1). Data sets from the Cancer [...]