NBS1 lactylation is required for efficient DNA repair and chemotherapy resistance.

The Warburg effect is a hallmark of cancer that refers to the preference of cancer cells to metabolize glucose anaerobically rather than aerobically1,2. This results in substantial accumulation of lacate, the end product of anaerobic glycolysis, in cancer cells3. However, how cancer metabolism affects chemotherapy response and DNA repair in general remains incompletely understood. Here we report that lactate-driven lactylation of NBS1 promotes homologous recombination (HR)-mediated DNA repair. Lactylation of NBS1 at lysine 388 (K388) is essential for MRE11-RAD50-NBS1 (MRN) complex formation and the accumulation of HR repair proteins at the sites of DNA double-strand breaks. Furthermore, we identify TIP60 as the NBS1 lysine lactyltransferase and the 'writer' of NBS1 K388 lactylation, and HDAC3 as the NBS1 de-lactylase. High levels of NBS1 K388 lactylation predict poor patient outcome of neoadjuvant chemotherapy, and lactate reduction using either genetic depletion of lactate dehydrogenase A (LDHA) or stiripentol, a lactate dehydrogenase A inhibitor used clinically for anti-epileptic treatment, inhibited NBS1 K388 lactylation, decreased DNA repair efficacy and overcame resistance to chemotherapy. In summary, our work identifies NBS1 lactylation as a critical mechanism for genome stability that contributes to chemotherapy resistance and identifies inhibition of lactate production as a promising therapeutic cancer strategy.

Twin-grasper assisted mucosal inverted closure achieves complete healing of large perforations after gastric endoscopic full-thickness resection.

OBJECTIVES: This study aimed to demonstrate the feasibility and safety of a novel twin-grasper assisted mucosal inverted closure (TAMIC) technique for large perforations after gastric endoscopic full-thickness resection (EFTR) in a porcine model. METHODS: Iatrogenic large perforations of the stomach were created and closed by an experienced endoscopist using the TAMIC technique in 12 pigs. Repeat gastroscopy was performed in 4 weeks after surgery to examine the wound sites and then the animals were killed. The primary outcomes were the successful TAMIC closure rate and the complete healing rate. Secondary end points included procedure time of TAMIC, complete inverted healing rate, delayed bleeding rate, and postsurgery perforation. Histologies of the wounds were analyzed by hematoxylin-eosin, Masson trichrome, and immunohistochemistry staining. RESULTS: The median size of the defects was 3.5 (range 2.5-4.5) cm. TAMIC was successfully performed in all the 12 pigs. Complete healing was achieved in 11 pigs 4 weeks after operation as one pig died postsurgery due to severe pneumonia. The median procedure time for TAMIC was 39 (range 23-81) min. The complete inverted healing rate was 45.5% (5/11). No delayed bleeding or postsurgery perforation was observed. Histologic analyses showed that both the epithelium and muscularis mucosae layers were appropriately connected under inverted healing. CONCLUSIONS: Twin-grasper assisted mucosal inverted closure is feasible and safe for closure of large perforations after gastric EFTR and could be a propagable and promising technique for clinical practice.

CPEB3 suppresses gastric cancer progression by inhibiting ADAR1-mediated RNA editing via localizing ADAR1 mRNA to P bodies.

Deciphering the crosstalk between RNA-binding proteins and corresponding RNAs will provide a better understanding of gastric cancer (GC) progression. The comprehensive bioinformatics study identified cytoplasmic polyadenylation element-binding protein 3 (CPEB3) might play a vital role in GC progression. Then we found CPEB3 was downregulated in GC and correlated with prognosis. In addition, CPEB3 suppressed GC cell proliferation, invasion and migration in vitro, as well as tumor growth and metastasis in vivo. Mechanistic study demonstrated CPEB3 interacted with 3'-UTR of ADAR1 mRNA through binding to CPEC nucleotide element, and then inhibited its translation by localizing it to processing bodies (P bodies), eventually leading to the suppression of ADAR1-mediated RNA editing. Microscale thermophoresis assay further revealed that the direct interaction between CPEB3 and GW182, the P-body's major component, was through the 440-698AA region of CPEB3 binding to the 403-860AA region of GW182. Finally, AAV9-CPEB3 was developed and administrated in mouse models to assess its potential value in gene therapy. We found AAV9-CPEB3 inhibited GC growth and metastasis. Besides, AAV9-CPEB3 induced hydropic degeneration in mouse liver, but did not cause kidney damage. These findings concluded that CPEB3 suppresses GC progression by inhibiting ADAR1-mediated RNA editing via localizing ADAR1 mRNA to P bodies.

Pleiotropic Roles of Atrial Natriuretic Peptide in Anti-Inflammation and Anti-Cancer Activity.

The atrial natriuretic peptide (ANP), a cardiovascular hormone, plays a pivotal role in the homeostatic control of blood pressure, electrolytes, and water balance and is approved to treat congestive heart failure. In addition, there is a growing realization that ANPs might be related to immune response and tumor growth. The anti-inflammatory and immune-modulatory effects of ANPs in the tissue microenvironment are mediated through autocrine or paracrine mechanisms, which further suppress tumorigenesis. In cancers, ANPs show anti-proliferative effects through several molecular pathways. Furthermore, ANPs attenuate the side effects of cancer therapy. Therefore, ANPs act on several hallmarks of cancer, such as inflammation, angiogenesis, sustained tumor growth, and metastasis. In this review, we summarized the contributions of ANPs in diverse aspects of the immune system and the molecular mechanisms underlying the anti-cancer effects of ANPs.

Synergistic Effect of a Facilely Synthesized MnV2O6 Catalyst on Improving the Low-Temperature Kinetic Properties of MgH2.

While magnesium hydride (MgH2) has drawn considerable attention as a promising hydrogen storage material, it suffers from sluggish kinetics and high desorption temperature, hindering potential applications. Herein, we show that the hydrogen desorption kinetics of MgH2 can be significantly improved using bimetallic oxide MnV2O6 as the catalyst. A MgH2-MnV2O6 composite was prepared by a high-energy ball milling method. The results showed that the MgH2-MnV2O6 composite can release 5.57 wt % hydrogen within 10 min under 250 °C. The dehydrogenated MgH2-MnV2O6 sample can absorb 3.09 wt % hydrogen within 10 min under 50 °C. Notably, the reversible hydrogen storage property did not degrade at least within 100 cycles, showing excellent cycle stability. X-ray diffraction and transmittance electron microscopy measurements revealed that MnV alloy and V2O3 phases were formed during the ball milling process, leading to the synergistic catalytic effect. We argue that the bimetallic MnV alloy plays key catalytic roles in this system because MnV alloy can promote the fracture of the H-H and Mg-H bonds, significantly improving the hydrogen storage kinetics and low-temperature reversible hydrogen storage performance of MgH2.

The association of immune cell infiltration and prognostic value of tertiary lymphoid structures in gastric cancer.

Tertiary lymphoid structures (TLS) are lymphoid aggregates in tumor tissues and their potential significance in clinical applications has not been fully elucidated in gastric cancer. We evaluated TLS and tumor-infiltrating immune cells using H&E and immunohistochemistry staining in the recruited patients with gastric cancer. The prognostic value of TLS was evaluated by Kaplan-Meier analysis and further validated using gene expression profiling. The alterations in gene mutation, copy number variance, and DNA methylation across the TLS signature subtypes were analyzed based on the Cancer Genome Atlas cohort. High TLS density was associated with improved overall survival and disease-free survival. A combination of TLS density and TNM stage obtained higher prognostic accuracy than the TNM stage alone. Tumors with high TLS density showed significantly higher infiltration of CD3+, CD8+, and CD20+ cells but lower infiltration of CD68+ cells. Transcriptomics analysis demonstrated that high TLS signature status was positively associated with the activation of inflammation-related and immune-related pathways. Multi-omics data showed a distinct landscape of somatic mutations, copy number variants, and DNA methylation across TLS signature subtypes. Our results indicated that TLS might link with enhanced immune responses, and represent an independent and beneficial predictor of resected gastric cancer. Multi-omics analysis further revealed key tumor-associated molecular alterations across TLS signature subtypes, which might help explore the potential mechanism of the interaction between TLS formation and cancer cells.

The O/S heteroatom effects of covalent triazine frameworks for photocatalytic hydrogen evolution.

S/O heterocyclic covalent triazine frameworks (CTFs i.e., CTF-7 and CTF-8) were synthesized using thiophene and furan as building blocks, respectively. The hydrogen evolution rate of CTF-7 is 7430 µmol g-1 h-1, which is about 5.6 times that of CTF-8. Due to their low electronegativity, sulfur heteroatoms are more favorable for charge separation than oxygen heteroatoms in CTFs. This work provides a guiding principle for the design of high efficiency photocatalyst structures.

KLF5 Is Activated by Gene Amplification in Gastric Cancer and Is Essential for Gastric Cell Proliferation.

Gastric cancer is the third leading cause of cancer death worldwide. In this study, we tried to clarify the function of KLF5 in gastric cancer. Copy number variation (CNV) and the expression of KLF5 were interrogated in public datasets. The clinical significance of KLF5 amplification and gene expression in gastric cancer were evaluated. The function of KLF5 in cell proliferation was studied in gastric cancer cell lines and organoids. We found that KLF5 amplification mainly occurred in the chromosome instable tumors (CIN) and was significantly associated with TP53 mutation. In addition, higher KLF5 expression correlated with more locally invasive gastric cancer and higher T stage. Next, a KLF5 gene expression signature was curated. The genes in the signature were involved in cell development, cell cycle regulation, cell death, suggesting potential roles played by KLF5. Functional studies using siRNAs revealed that KLF5 was essential for the proliferation of gastric cancer cells. Finally, using gastric organoid models, we revealed that the proliferation of organoids was significantly inhibited after the down regulation of KLF5. Our study revealed that KLF5 was amplified and over-expressed in gastric cancer, and it may play an oncogene-like role in gastric cancer by supporting cell proliferation.

Determination of log P by dispersive liquid/liquid microextraction coupled with derivatized magnetic nanoparticles predispersed in 1-octanol phase.

A new direct method for log P determination by dispersive liquid/liquid microextraction (DLLME) coupled with derivatized magnetic nanoparticles (DMNPs) predispersed in 1-octanol phase is discussed. First, the aim of DMNPs predispersed into 1-octanol phase was to provide the magnetic force when an ultrastrong magnet was used to separate the two phases. Second, the interaction of 1-octanol with inner DMNPs nuclei prevented emulsion formation in the DLLME process. Moreover, interruption of absorption of DMNPs due to the partition equilibrium of the model compound was negligible. The equilibrium of model compound between the two phases was reached in less than 3 min. The two phases were separated quickly by a super magnet because model compounds in the two phases did not interfere with each other. Fourteen model compounds of varied log P values were measured using this method. The log P values fall in the range of 0.6 to 4.8, which are in agreement with the published results. This method is a rapid, efficient and facile method for direct measurement of log P values.

Structure and stability of B5C and C5B clusters.

Geometry optimizations and vibrational frequencies of B5C and C5B clusters were calculated with the Becke-3LYP method using the 6-311+G(d) basis set and some stable configurations of B5C and C5B clusters have been found. The most stable structure of B5C is a planar six-membered ring. However, for C5B clusters, the most stable structure is linear with a boron atom in position 3. Various configurations of B5C clusters containing three-membered boron rings have predominance in energy, whereas various configurations of C5B clusters containing three-membered carbon rings are disadvantageous in energy. In B5C clusters, isomer2 can be converted into isomer1 by surmounting an energy barrier of 43.83 kJ.mol(-1). In C5B clusters, the conversions of isomer5 into isomer2 and isomer7 into isomer2 have energy barriers of 19.66 and 20.57 kJ.mol(-1), respectively.

A hollow fiber solvent microextraction approach to measure drug-protein binding.

A new direct method has been developed to determine protein-drug binding based on hollow fiber membrane solvent microextraction. Hollow-fiber membrane solvent microextraction coupled with high-performance chromatography with UV detection was employed to evaluate the binding characteristics of drugs to bovine serum albumin (BSA) and blood serum. It was found that the BSA and matrix in the blood serum did not interfere with the measurement. The method is simple and fast. It lacks the drawbacks of some conventional analytical techniques, such as taking much long time and requiring large volume sample consumption.

[Determination of chlorhexidine acetate in chlorhexidine acetate suppositories by high performance liquid chromatography coupled with hollow fiber membrane solvent microextraction].

A novel method was developed to determine the content of chlorhexidine acetate (CA) in chlorhexidine acetate suppositories by high performance liquid chromatography (HPLC) coupled with hollow fiber membrane solvent microextraction. The sample was extracted with 1.5 mol/L acetic acid solution five times, then a hollow fiber containing n-octanol was placed in the sample solution to perform microextraction for extracting 20 min. The extract was analyzed by HPLC with UV detection at 260 nm. The chromatographic conditions were as following: acetonitrile-redistilled water (29:71, v/v, containing 0.3% triethylamine, pH 3.0) as mobile phase with the flow rate of 1 mL/min. The calibration curve of CA was linear from 0.5 to 16 mg/L. The method recovery was over 98.0% with relative standard deviation less than 4.0%. By using hollow fiber membrane solvent microextraction, the enrichment of 24-fold was achieved. The method is specific, simple, fast, sensitive and suitable for the determination of chlorhexidine acetate.