DNMT1-mediated epigenetic suppression of FBXO32 expression promoting cyclin dependent kinase 9 (CDK9) survival and esophageal cancer cell growth

Esophageal cancer (EC) is a common and serious form of cancer, and while DNA methyltransferase-1 (DNMT1) promotes DNA methylation and carcinogenesis, the role of F-box protein 32 (FBXO32) in EC and its regulation by DNMT1-mediated methylation is still unclear. FBXO32 expression was examined in EC cells with high DNMT1 expression using GSE163735 dataset. RT-qPCR assessed FBXO32 expression in normal and EC cells, and impact of higher FBXO32 expression on cell proliferation, migration, and invasion was evaluated, along with EMT-related proteins. The xenograft model established by injecting EC cells transfected with FBXO32 was used to evaluate tumor growth, apoptosis, and tumor cells proliferation and metastasis. Chromatin immunoprecipitation (ChIP) assay was employed to study the interaction between DNMT1 and FBXO32. HitPredict, co-immunoprecipitation (Co-IP), and Glutathione-S-transferase (GST) pulldown assay analyzed the interaction between FBXO32 and cyclin dependent kinase 9 (CDK9). Finally, the ubiquitination assay identified CDK9 ubiquitination, and its half-life was measured using cycloheximide and confirmed through western blotting. DNMT1 negatively correlated with FBXO32 expression in esophageal cells. High FBXO32 expression was associated with better overall survival in patients. Knockdown of DNMT1 in EC cells increased FBXO32 expression and suppressed malignant phenotypes. FBXO32 repressed EC tumor growth and metastasis in mice. Enrichment of DNMT1 in FBXO32 promoter region led to increased DNA methylation and reduced transcription. Mechanistically, FBXO32 degraded CDK9 through promoting its ubiquitination.</p

Large-Scale Manual Grinding Preparation of Ultrathin Porous Sulfur (S₈)‑Anchored ScOOH Nanosheets for Photothermal Conversion and Dye Adsorption

Porous two-dimensional (2D) nanomaterials have attracted much attention in recent years and shown unique electronic and physicochemical properties by utilizing the advantages of both porous structure and 2D architecture. However, the low-cost, large-scale, and high-quality synthesis of porous 2D nanomaterials is still very challenging. Herein, for the first time, we develop a facile manual grinding strategy for the preparation of ultrathin porous sulfur (S8)-anchored ScOOH nanosheets (S8/ScOOH-NSs) by the mechanical stripping of S8-anchored ScOOH nanorods (S8/ScOOH-NRs). The formation of S8/ScOOH-NSs should be due to the intrinsic lamellar structure of S8/ScOOH-NRs. The obtained S8/ScOOH-NSs with rich mesopores have a high-quality crystal structure. Because of hydrophobic sulfur and carbon components on the surface, S8/ScOOH-NSs show good hydrophobicity. In addition, S8/ScOOH-NSs exhibit more excellent photothermal conversion efficiency and adsorption capacity compared with S8/ScOOH-NRs, which is directly attributed to the synergistic effect of sulfur-doping, porous structure, and 2D architecture. Therefore, the facile and large-scale synthesis strategy endows S8/ScOOH-NSs with multifunctional properties that have great application prospects in water cleaning and photothermal evaporators

Robust Strain in Freestanding Single-Crystal SrRuO₃ Membranes

Freestanding membranes provide a unique opportunity to integrate complex oxides with mature semiconductor technologies and flexible electronics. It is known that the physical functionalities of complex oxides can be modified by epitaxial strain induced by the underneath substrates. The strain release may degrade the physical properties of the freestanding oxide membranes. Here, we demonstrate that various strain states in the pristine epitaxial films can be well preserved in the freestanding single-crystal SrRuO3 (SRO) membranes using the sacrificial layers with high lattice flexibility. Tensile and compressive strains are induced by the water-soluble sacrificial layers of Sr3Al2O6 (SAO) and Sr2CaAl2O6 (SCAO) on SrTiO3 substrates, respectively. An atomically flat surface morphology and initial strain states are maintained in the freestanding SRO membranes after etching the SAO and SCAO layers in water. In light of this, the electrical and magnetic properties of the SRO membranes are comparable to those of the corresponding strained films before exfoliation but completely different from those of the fully relaxed SRO films. The robust strain in the freestanding membranes offers the ability to integrate the strain-modified functionality of complex oxides with the conventional silicon-based semiconductor or flexible electronics