Explore the vast range of titles available.

Recently, patients with advanced cancers have been benefited greatly from immune checkpoint blockade immunotherapy. However, immune checkpoint blockade is still suboptimal in HCC treatment and more immune modifications are needed to achieve an efficient therapeutic goal. Here, we investigated the combined administration of a Listeria-based HCC vaccine, Lmdd-MPFG, and the anti-PD-1 immune checkpoint blockade antibody. We found that Lmdd-MPFG promoted the expression of PD-L1 in HCC cells but resensitized the tumor local T cell to respond to the anti-PD-1 immunotherapy. Mechanistically, the Lmdd-MPFG vaccine activates the NF-κB pathway in the tumor-associated macrophages (TAMs) through the TLR2 and MyD88 pathway, and recruits p62 to activate the autophagy pathway. The overall effect is skewing the TAMs from M2-polarized TAMs into the M1-polarized TAMs. Most importantly, it skewed the cytokine profiles into antitumor one in the tumor microenvironment (TME). This change restores the T-cell reactivity to the anti-PD-1 blockade. Our results suggested that Lmdd-MPFG combined with PD-1 blockade exerted synergistic antitumor effects through modifying TAMs in the TME and removing T-cell inhibitory signals, thereby providing a new potential strategy for HCC treatment.

In many types of cancer, tumor cells prefer to use glycolysis as a major energy acquisition method. Here, we found that the 18 fluoro-deoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT)-based markers were positively associated with the expression of programmed cell death ligand 1 (PD-L1), pyruvate kinase M2 (PKM2), both of which indicate poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). However, the regulatory mechanism of PD-L1 remains elusive. In this study, we confirmed that transforming growth factor-beta1 (TGF-β1) secreted by tumor-associated macrophages (TAMs) was a key factor contributing to the expression of PD-L1 in PDAC cells by inducing the nuclear translocation of PKM2. Using co-immunoprecipitation and chromatin immunoprecipitation assays, we demonstrated that the interaction between PKM2 and signal transducer and activator of transcription 1 (STAT1) was enhanced by TGF-β1 stimulation, which facilitated the transactivation of PD-L1 by the binding of PKM2 and STAT1 to its promoter. In vivo, PKM2 knockdown decreased PD-L1 expression in PDAC cells and inhibited tumor growth partly by promoting natural killer cell activation and function, and the combination of PD-1/PD-L1 blockade with PKM2 knockdown limited tumor growth. In conclusion, PKM2 significantly contributes to TAM-induced PD-L1 overexpression and immunosuppression, providing a novel target for immunotherapies for PDAC.

BackgroundThe significance of the relationship between the microbiota and diseases is increasingly being recognized. However, the characterization of tumor microbiome and their precise molecular mechanisms through which microbiota promotes hepatocellular carcinoma (HCC) development are still unclear.MethodsThe intrahepatic microbiota was investigated from tumor, normal adjacent tissues in 46 patients with HCC and normal hepatic tissues in 33 patients with hemangioma by 16S rRNA gene sequencing. Taxonomic composition differences in patients were evaluated using Linear discriminant analysis Effect Size (LefSe) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) to predict microbial functional pathways. Associations between the most relevant taxa and clinical characteristics of HCC patients were analyzed by Spearman rank correlations. The effects of microbe on hepatic stellate cells (HSCs) activation and HCC progression were examined.ResultsWe observed intrahepatic microbiota disturbances by reduced microbial diversity in HCC. The tumor microbiota of the HCC patients with cirrhosis showed higher abundance of Stenotrophomonas maltophilia (S. maltophilia). S. maltophilia provoked senescence-associated secretory phenotype (SASP) in HSCs by activating TLR-4-mediated NF-κB signaling pathway, which in turn induced NLRP3 inflammasome complex formation and secreted various inflammatory factors in the liver, thus facilitating HCC progression in mice. Moreover, signs of SASP were also observed in the HSCs in the area of HCC with higher S. maltophilia enrichment arising in patients with cirrhosis.ConclusionsOur analysis of the hepatic microbiota revealed for the first time that patients with HCC exhibited a dysbiotic microbial community with higher S. maltophilia abundance, which induced the expression SASP factors of HSCs and cirrhosis in the liver, concurring in the process of hepatocarcinogenesis.

Stevia rebaudiana Bertoni is recognized as the third major source of natural sweetness due to its leaves being rich in high-sweetness, low-calorie steviol glycosides (SGs). A crucial enzyme in the metabolic glycosylation grid of SGs, uridine diphosphate glycosyltransferase SrUGT85C2 catalyzes the glycosylation of the C 13 -hydroxyl of the steviol, creating a β-D-glucoside link and 13-steviol monoside. However, the key residues of the SrUGT85C2 enzyme and how SrUGT85C2 affects the accumulation of SGs in S. rebaudiana remain unclear. In this study, cloning and functional analysis of SrUGT85C2 gene sequences were performed in 10 different S. rebaudiana genotypes with divergent SG compositions. After sequences analysis, eleven variants of this gene were identified. The mutants N05-5 and N02-6, for which no catalytic function was detected, caused changes in substrate binding and pocket conformation due to single amino acid substitutions, thereby hindering the approach of the reaction group. Molecular docking analysis suggested that mutants N02-1, N02-5 and 023 − 3 increase the efficiency of steviol conversion, potentially by forming additional hydrogen bonds. Because steviol-19-O-glucoside (19-SMG) and UDP-glucose (UDPG) overlap spatially, mutants 11-14-5 and N01-1 prevent C 19 -glycosylation. Molecular docking-based site-directed mutagenesis verified that steviol and 19-SMG catalytic activity were enhanced by the mutant proteins K25H and E418G to 164.1% and 203.6% of the SrUGT85C2 protein, respectively. In addition, the expression analysis of SrUGT85C2 in each genotypes showed that the expression levels of the gene varied significantly among genotypes, with high expression observed in GP. K25 and E418 were also found to be effective positive mutation sites for SrUGT85C2 in this work, offering a theoretical foundation for the production of premium S. rebaudiana materials and the effective microbial synthesis of optimal steviol glycosides.

BackgroundThe immune response within the tumor microenvironment plays a key role in tumorigenesis and determines the clinical outcomes of head and neck squamous cell carcinoma (HNSCC). However, to date, a paucity of robust, reliable immune-related biomarkers has been identified that are capable of estimating prognosis in HNSCC patients.MethodsHigh-throughput RNA sequencing was performed in tumors and matched adjacent tissues from five HNSCC patients, and the immune signatures expression of 730 immune-related transcripts selected from the nCounter PanCancer Immune Profiling Panel were assessed. Survival analyzes were performed in a training cohort, consisting of 416 HNSCC cases, retrieved from The Cancer Genome Atlas (TCGA) database. A prognostic signature was built, using elastic net-penalized Cox regression and backward, stepwise Cox regression analyzes. The outcomes were validated by an independent cohort of 115 HNSCC patients, using tissue microarrays and immunohistochemistry staining. Cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) was also used to estimate the relative fractions of 22 immune-cell types and their correlations coefficients with prognostic biomarkers.ResultsCollectively, 248 immune-related genes were differentially expressed in paired tumors and normal tissues using RNA sequencing. After process screening in the training TCGA cohort, four immune-related genes (PVR, TNFRSF12A, IL21R, and SOCS1) were significantly associated with overall survival (OS). Integrating these genes with Path_N stage, a multiplex model was built and suggested better performance in determining 5 years OS (receiver operating characteristic (ROC) analysis, area under the curve (AUC)=0.709) than others. Further protein-based validation was conducted in 115 HNSCC patients. Similarly, high expression of PVR and TNFRSF12A were associated with poor OS (Kaplan-Meier p=0.017 and 0.0032), while high expression of IL21R and SOCS1 indicated favorable OS (Kaplan-Meier p<0.0001 and =0.0018). The integrated model with Path_N stage still demonstrated efficacy in OS evaluation (Kaplan-Meier p<0.0001, ROC AUC=0.893). Besides, the four prognostic genes were significantly correlated with activated CD8+ T cells, CD4+ T cells, follicular helper T cells and regulatory T cells, implying the possible involvement of these genes in the immunoregulation and development of HNSCC.ConclusionsThe well-established model encompassing both immune-related biomarkers and clinicopathological factor might serve as a promising tool for the prognostic prediction of HNSCC.

Non-structural carbohydrates (NSCs) are an important energy source for plant growth and metabolism. Analysis of NSC changes can provide important clues to reveal the adaptation mechanisms of plants to a specific environment. Although considerable differences have been reported in NSCs in response to nitrogen (N) application among crop species and cultivars, previous studies have mostly focused on the differences in leaves and stems. However, the effects of N on the characteristics of accumulation and translocation of NSC in maize with different levels of N tolerance remain unclear. To determine differences in the N levels, two cultivars (N-efficient ZH311 and N-inefficient XY508) were grown in field pots (Experiment I) and as hydroponic cultures (Experiment II) and were supplemented with different concentrations of N fertilizer. In both experiments, low-N stress significantly increased the accumulation of NSCs in maize vegetative organs and increased the translocation rate of NSCs in the stems and their apparent contribution to yield, thereby reducing the yield loss caused by low-N stress. N application had a greater effect on starch content in the vegetative organs of ZH311, but had less effect on soluble sugar (SS) and NSC content in the whole plant and starch content in the ears. ZH311 could convert more starch into SS under low N conditions to adapt to low N environments than XY508, while ensuring that grain yield and starch quantity were not affected. This is evidently an important physiological mechanism involved in this cultivar's tolerance to low N conditions.

Retinoblastoma (RB) is the most common childhood malignant intraocular tumor. The clinical efficacy of vincristine (VCR) in the treatment of RB is severely limited by drug resistance. Here, we found that CD24, a GPI‐anchored protein, was overexpressed in human RB tissues and RB cell lines, and was associated with the sensitivity of RB cells in response to VCR therapy. We demonstrated that CD24 plays a critical role in impairing RB sensitivity to VCR via regulating autophagy. Mechanistically, CD24 recruits PTEN to the lipid raft domain and regulates the PTEN/AKT/mTORC1 pathway to activate autophagy. Lipid raft localization was essential for CD24 recruitment function. Collectively, our findings revealed a novel role of CD24 in regulating RB sensitivity to VCR and showed that CD24 is a potential target for improving chemotherapeutic sensitivity and RB patient outcomes. Chemotherapy failure is the major cause of recurrence and poor prognosis in retinoblastoma (RB) patients. We found that CD24 is overexpressed in human RB tissues and RB cell lines, and is associated with the sensitivity of RB cells to VCR therapy. CD24, a GPI‐anchored protein linked to membrane lipid raft microdomains, recruits PTEN to the lipid raft domain and regulates the PTEN/AKT/mTORC1 pathway to activate autophagy. Our study shows that CD24 blunts the sensitivity of RB to VCR via activating autophagy.

Background: Morus alba L. (family Moraceae) is widely cultivated across the world and is well-known for its medicinal and nutritional value, especially its leaves. This study investigates the regional variation in mulberry leaf metabolites, focusing on alkaloids and flavonoids, and explores the influence of climatic and environmental factors on their biosynthesis using an integrated metabolomic and environmental analysis. Mulberry leaves, known for their medicinal and nutritional value, were collected from six regions across China, including Sichuan, Xinjiang, and Tibet. Methods: Untargeted metabolomics via UHPLC-MS was conducted. Differential metabolites were identified through multivariate analysis and annotated using the KEGG database. Redundancy analysis was used to link metabolite profiles with climatic data. Results: Mulberry leaves from six Chinese regions showed significant variation in total flavonoid content (TFC), total polyphenol content (TPC), and 1-Deoxynojirmycin (DNJ), with Tibet having the highest TFC and TPC, and Panzhihua the highest DNJ. Metabolomic analysis identified 3794 metabolites, revealing distinct regional clustering. A total of 79 differential metabolites were identified, which are enriched in pathways such as galactose metabolism and phenylalanine biosynthesis. Environmental factors, especially bio3, bio10, bio2, bio5, and bio20, strongly influenced metabolite profiles. Conclusions: The biosynthesis and accumulation of secondary metabolites in mulberry leaves are significantly influenced by region-specific environmental factors, particularly temperature, precipitation, and light. The identified differential metabolites are mainly enriched in galactose metabolism, arginine, and proline metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis. These pathways are closely associated with plant stress responses and the synthesis of secondary metabolites. The pronounced regional differences in metabolite profiles underscore the critical role of environmental factors in determining the chemical composition of mulberry leaves. This research provides valuable insights into the influence of climatic factors affecting the chemical composition of plants. It lays a theoretical foundation for the quality assessment and grading of mulberry leaves, providing scientific guidance for their targeted cultivation and utilization.

Iron (Fe) deficiency is a common challenge in crop production. Screening and research of Fe-efficient cultivars could alleviate plant stress and increase crop yields in Fe-deficient soils. In the present study, we conducted two hydroponic culture experiments with a control (100 [mu]mol/L Fe.sup.3+ -EDTA) and low Fe treatment (10 [mu]mol/L Fe.sup.3+ -EDTA) to study the morphological and physiological mechanisms of response to low Fe stress in maize hybrids seedlings. In the first experiment, we investigated 32 major maize hybrids in Southwest China. We found that six of them, including Zhenghong 2 (ZH 2), were Fe-efficient. Fifteen other cultivars, such as Chuandan 418 (CD 418), were Fe-inefficient. In the second experiment, we investigated the Fe-efficient ZH 2 and Fe-inefficient CD 418 cultivars and found that low Fe stress resulted in significant decreases in root volume, root length, number of root tips, root surface area, and root dry weight, and increased root to shoot ratio, average root diameter, and Fe-dissolution ability per mass of roots in both maize cultivars. However, the increase in Fe-dissolution ability per mass of roots in ZH 2 was higher than that in CD 418, whereas for the other measurements, the low Fe stress-induced changes in ZH 2 were less pronounced than in CD 418. Therefore, under low Fe stress, the above-mentioned growth factors in ZH 2 were higher by 54.84%, 121.46%, 107.67%, 83.96%, 140.00%, and 18.16%, respectively, than those in CD 418. In addition, leaf area, chlorophyll content, net photosynthetic rate, soluble protein content, and Catalase (CAT) and Peroxidase (POD) activities in ZH 2 were higher by 274.95%, 113.95%, 223.60%, 56.04%, 17.01% and 21.13% than those in CD 418. Therefore, compared with the Fe-inefficient cultivar (CD 418), the Fe-efficient cultivar (ZH 2) had a more developed root system and greater Fe absorption capacity per mass of roots under low iron stress, promoted the efficient absorption of Fe, maintained a higher photosynthetic area and photosynthetic rate, thereby facilitating the accumulation of photosynthetic products. Moreover, higher soluble protein content and activities of CAT and POD permitted high osmotic regulation and scavenging ability, which is an important physiological mechanism for ZH 2 adaptation to low Fe stress.