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Abstract Gastric cancer (GC) remains a significant global health challenge due to its high morbidity and mortality rates. The development of GC is a multi-hit process and the exploration of precancerous lesions is crucial. To elucidate the molecular and cellular dynamics underlying gastric carcinogenesis, we conducted an integrative single-cell RNA sequencing analysis of 26,028 high-quality cells from gastric antral mucosa biopsies across various stages, including non-atrophic gastritis, chronic atrophic gastritis, intestinal metaplasia, and early gastric cancer. By constructing a detailed single-cell atlas, we identified distinct epithelial cell subpopulations and their corresponding molecular signatures. We focused on the biological link between gastric epithelial cells and cancer cells. Notably, we observed that gland mucous cells acquired an intestinal-like stem cell phenotype during metaplasia, with MUC6, MUC2 and OLFM4 emerging as the specific markers for unique endocrine cells in early malignant lesions. Additionally, our analysis highlighted UPP1 as a key oncogene, with its expression progressively increasing from normal epithelial cells to malignant cells. UPP1 upregulation was shown to promote GC cell proliferation and migration, implicating it in the oncogenic process. Further, we explored the impact of Helicobacter pylori infection on gene expression, revealing that Helicobacter pylori infection upregulates UPP1 via the NF-κB pathway. Our cell-cell communication analysis underscored the significant role of the Macrophage migration inhibitory factor pathway in the tumor microenvironment, contributing to GC progression. Various key molecules involved in intestinal metaplasia, along with UPP1 and the Macrophage migration inhibitory factor pathway, collectively illustrate the multifaceted nature and complexity of gastric cancer evolution, highlighting the cumulative impacts that drive tumorigenesis.

Introduction: Gliomas are the most common and aggressive type of primary brain tumor, with a poor prognosis despite current treatment approaches. Understanding the molecular mechanisms underlying glioma development and progression is critical for improving therapies and patient outcomes. Methods: The current study comprehensively analyzed large-scale single-cell RNA sequencing and bulk RNA sequencing of glioma samples. By utilizing a series of advanced computational methods, this integrative approach identified the gene UPP1 (Uridine Phosphorylase 1) as a novel driver of glioma tumorigenesis and immune evasion. Results: High levels of UPP1 were linked to poor survival rates in patients. Functional experiments demonstrated that UPP1 promotes tumor cell proliferation and invasion and suppresses anti-tumor immune responses. Moreover, UPP1 was found to be an effective predictor of mutation patterns, drug response, immunotherapy effectiveness, and immune characteristics. Conclusions: These findings highlight the power of combining diverse machine learning methods to identify valuable clinical markers involved in glioma pathogenesis. Identifying UPP1 as a tumor growth and immune escape driver may be a promising therapeutic target for this devastating disease. [ABSTRACT FROM AUTHOR]

Glycolysis is vital for the excessive proliferation of keratinocytes in psoriasis, and uridine phosphorylase‐1 (UPP1) functions as an enhancer of cancer cell proliferation. However, little is known about whether UPP1 promotes keratinocyte proliferation and accelerates psoriasis development. This study revealed that UPP1 facilitates cell viability and cell‐cycle progression in human epidermal keratinocytes (HEKs) by modulating the glycolytic pathway. Bioinformatics analysis of UPP1 gene expression and its correlation with the Reactome revealed that UPP1 mRNA expression, cell‐cycle progression, the interleukin‐6 (IL‐6)/Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway and glycolysis were positively associated with psoriasis. Cell proliferation, the cell cycle and glycolysis were evaluated after UPP1 was silenced or overexpressed. The results showed that UPP1 overexpression increased cell proliferation, cell‐cycle progression and glycolysis, which was contrary to the effects of UPP1 silencing. However, the STAT3 inhibitor diminished UPP1 expression because STAT3 can bind to the UPP1 promoter. In conclusion, UPP1 was significantly activated by the IL‐6/STAT3 pathway and could modulate glycolysis to regulate cell proliferation and cell‐cycle progression in keratinocytes during the development of psoriasis. [ABSTRACT FROM AUTHOR]

Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen that targets pig intestines to cause disease. It is globally widespread and causes huge economic losses to the pig industry. PEDV N protein is the protein that constitutes the core of PEDV virus particles, and most of it is expressed in the cytoplasm, and a small part can also be expressed in the nucleus. However, the role of related proteins in host nucleotide metabolic pathways in regulating PEDV replication have not been fully elucidated. In this study, PEDV-N-labeled antibodies were co-immunoprecipitated and combined with LC-MS to screen for host proteins that interact with N proteins. Bioinformatics analyses showed that the selected host proteins were mainly enriched in metabolic pathways. Moreover, coimmunoprecipitation and confocal microscopy confirmed that the secondlargest subunit of RNA polymerase II (RPB2) and uridine phosphorylase 1 (UPP1) interacted with the N protein. RPB2 is the main subunit of RNA polymerase II and plays an important role in eukaryotic transcription. UPP1 is an enzyme that catalyzes reversible phosphorylation of uridine to uracil and ribo-1-phosphate to promote catabolism and bio anabolism. RPB2 overexpression significantly promoted viral replication, whereas UPP1 overexpression significantly inhibited viral replication. Studies on interactions between the PEDV N and host proteins are helpful in elucidating the pathogenesis and immune escape mechanism of PEDV. [ABSTRACT FROM AUTHOR]

Nucleosides and nucleic acids are abundant in our diet, but their nutritional value has been poorly investigated. Nucleosides maintain the viability of cells and organs when glucose is limited. Specific nucleoside phosphorylases, including uridine phosphorylase 1/2 (UPP1/2), thymidine phosphorylase (TYMP), and purine nucleoside phosphorylase (PNP), catalyze nucleoside cleavage and release of the ribose moiety, which can enter the glycolytic pathway, thus fueling central carbon metabolism. UPP1/2 integrate genetic and environmental signals to regulate uridine catabolism. Energy production from nucleosides has major implications for metabolism, immunity, and cancer. From our daily nutrition and synthesis within cells, nucleosides enter the bloodstream and circulate throughout the body and tissues. Nucleosides and nucleotides are classically viewed as precursors of nucleic acids, but recently they have emerged as a novel energy source for central carbon metabolism. Through catabolism by nucleoside phosphorylases, the ribose sugar group is released and can provide substrates for lower steps in glycolysis. In environments with limited glucose, such as at sites of infection or in the tumor microenvironment (TME), cells can use, and may even require, this alternative energy source. Here, we discuss the implications of these new findings in health and disease and speculate on the potential new roles of nucleosides and nucleic acids in energy metabolism. [ABSTRACT FROM AUTHOR]

Yin Li,1,* Manling Jiang,2,3,* Yongqi Wei,1,* Xiang He,2 Guoping Li,2,* Chunlai Lu,1 Di Ge1 1Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, People’s Republic of China; 2Laboratory of Allergy and Precision Medicine, Chengdu Institute of Respiratory Health, Affiliated Hospital of Southwest Jiaotong University, The Third People’s Hospital of Chengdu, Chengdu, Sichuan, People’s Republic of China; 3State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science & Technology, Taipa, Macao Special Administrative Region of China*These authors contributed equally to this workCorrespondence: Chunlai Lu; Di Ge, Email lu.chunlai@zs-hospital.sh.cn; ge.di@zs-hospital.sh.cnBackground: The pyrimidine salvage pathway plays a critical role in tumor progression and patient outcomes. The roles of pyrimidine salvage pathway-related genes (PSPGs) in cancer, however, are not fully understood. This study aims to depict the characteristics of PSPGs across various cancers.Methods: An integrative pan-cancer analysis of six PSPGs (CDA, UCK1, UCK2, UCKL1, UPP1, and UPP2) was conducted using TCGA data, single-cell RNA sequencing datasets, and patient samples. Single-cell transcriptome analysis and RT-qPCR were used to validate the relation between UPP1 and cytokines. Flow cytometry was performed to validate the role of UPP1 in immune checkpoint regulation. The correlation between UPP1 and tumor associated neutrophils (TAN) were investigated and validated by single-cell transcriptome analysis and tissue microarrays (TMAs).Results: PSPGs showed low mutation rates but significant copy number variations, particularly amplifications in UCKL1, UPP1, and UCK2 across various cancers. DNA methylation patterns varied, with notable negative correlations between methylation and gene expression in UPP1. PSPGs were broadly up-regulated in multiple cancers, with correlations to clinical staging and prognosis. Proteomic data further confirmed these findings. Functional analysis revealed PSPGs’ associations with tumor proliferation, metastasis, and various signaling pathways. UPP1 showed strong correlations with the tumor microenvironment (TME), particularly with cytokines, immune checkpoints, and various immune cells. Single-cell transcriptome analysis confirmed these associations, highlighting UPP1’s influence on cytokine expression and immune checkpoint regulation. In esophageal squamous cell carcinoma (ESCC), UPP1-high tumor cells were significantly associated with immunosuppressive cells in the TME. Spatial analysis using TMAs revealed that UPP1+ tumor cells were predominantly located at the invasive margin and closely associated with neutrophils, correlating with poorer patient prognosis.Conclusion: Our study depicted the multi-dimensional view of PSPGs in cancer, with a particular focus on UPP1’s role in the TME. Targeting UPP1 holds promise as a potential strategy for cancer therapy.Keywords: pyrimidine salvage pathways, UPP1, microenvironment

Aberrant activation of hepatocyte growth factor (HGF) and its receptor c-Met axis promotes tumor growth. Therefore, many clinical trials have been conducted. A phase 3 trial investigating a monoclonal antibody targeting HGF in combination with fluoropyrimidine-based chemotherapy had to be terminated prematurely; however, the reason behind the failure remains poorly defined. In this study, we investigated the influence of HGF on the antineoplastic effects of 5-fluorouracil (5-FU), a fluoropyrimidine, in HepG2 cells. HGF suppressed the proliferative activity of cells concomitantly treated with 5-FU more robustly as compared to that of cells treated with 5-FU alone, and markedly increased the expression of uridine phosphorylase 1 (UPP1). Intracellular concentration of 5-fluorouridine, an initial anabolite of 5-FU catalyzed by UPP1, was increased by HGF. Interestingly, erlotinib enhanced HGF-induced increase in UPP1 mRNA; in contrast, gefitinib suppressed it. Furthermore, erlotinib suppressed HGF-increased phosphorylation of the epidermal growth factor receptor at the Tyr1173 site involved in downregulation of extracellular signal-regulated kinase (Erk) activation, and enhanced the HGF-increased phosphorylation of Erk. Collectively, these findings suggest that inhibition of the HGF/c-Met axis diminishes the effects of fluoropyrimidine through downregulation of UPP1 expression. Therefore, extreme caution must be exercised in terms of patient safety while offering chemotherapy comprising fluoropyrimidine concomitantly with inhibitors of the HGF/c-Met axis. [ABSTRACT FROM AUTHOR]

Abstract Uridine phosphorylase 1 (UPP1) has been reported as an oncogene in several malignancies. In glioma, the role of UPP1 remains unclear. This study was performed to explore its role in glioma at transcriptional level. Totally, 998 glioma patients with clinical data were enrolled, including 301 mRNA microarray data from Chinese Glioma Genome Atlas (CGGA) dataset and 697 RNAseq data from The Cancer Genome Atlas (TCGA) dataset. Statistical analysis was performed with R language. UPP1 expression level was positively correlated with WHO grade of glioma. UPP1 was significantly upregulated in mesenchymal subtype and could serve as a potential biomarker for this subtype. Based on most correlated genes of UPP1, Gene ontology analysis revealed that UPP1 was profoundly associated with immune and inflammatory response. Gene Sets Variation Analysis was further performed and showed that UPP1 was particularly correlated with MHC‐II and LCK, which were mainly associated with activities of antigen‐presenting cells and T cells. Moreover, UPP1 was found to be synergistic with various immune checkpoint members, especially with PD1 pathway and B7‐H3. Finally, Kaplan‐Meier curves revealed that higher UPP1 indicated significantly shorter survival for glioma patients. Taken together, UPP1 played an oncogenic role in glioma via suppressing tumor‐related immune response.

Uridine phosphorylase 1 (UPP1) has been reported as an oncogene in several malignancies. In glioma, the role of UPP1 remains unclear. This study was performed to explore its role in glioma at transcriptional level. Totally, 998 glioma patients with clinical data were enrolled, including 301 mRNA microarray data from Chinese Glioma Genome Atlas (CGGA) dataset and 697 RNAseq data from The Cancer Genome Atlas (TCGA) dataset. Statistical analysis was performed with R language. UPP1 expression level was positively correlated with WHO grade of glioma. UPP1 was significantly upregulated in mesenchymal subtype and could serve as a potential biomarker for this subtype. Based on most correlated genes of UPP1, Gene ontology analysis revealed that UPP1 was profoundly associated with immune and inflammatory response. Gene Sets Variation Analysis was further performed and showed that UPP1 was particularly correlated with MHC‐II and LCK, which were mainly associated with activities of antigen‐presenting cells and T cells. Moreover, UPP1 was found to be synergistic with various immune checkpoint members, especially with PD1 pathway and B7‐H3. Finally, Kaplan‐Meier curves revealed that higher UPP1 indicated significantly shorter survival for glioma patients. Taken together, UPP1 played an oncogenic role in glioma via suppressing tumor‐related immune response. [ABSTRACT FROM AUTHOR]

Thyroid cancer incidence has been continuity increasing worldwide. Uridine phosphorylase 1 (UPP1) is a protein‐coding gene and has been detected that UPP1 was the higher expression in many solid malignancies, just as head and neck cancers, breast cancer, compared with paired normal tissue. But the act of UPP1 in thyroid cancer is not explicit. In this article, we investigate the function of UPP1 expression in thyroid cancer. The Cancer Genome Atlas (TCGA) unpaired thyroid cancer and normal RNA‐seq data were downloaded, and our paired thyroid cancer and normal samples were analysed by a polymerase chain reaction. The expression of UPP1 was regulated by transfected small interfering RNA, and the function of UPP1 was determined via migration, invasion and cell proliferation assays. Western blot assay was achieved to determine the UPP1 expression correlates with the function of 5‐FU regulate epithelial‐mesenchymal transition. The significant upregulation of UPP1 in thyroid cancer tissues compared with normal thyroid tissues was revealed by our data and TCGA data. UPP1 overexpression was significantly correlated with lymph node metastasis, tumour stage and tumour size. In the cell, experiments showed that UPP1 low expression significantly suppressed the migration, invasion and proliferation. Western blot assay proves the effect of UPP1 expression on 5‐FU regulates epithelial‐mesenchymal transition pathway. UPP1 plays a crucial oncogene in thyroid cancer. Our findings indicate that UPP1 might be a biomarker of thyroid cancer and may act by regulating epithelial‐mesenchymal transition (EMT). [ABSTRACT FROM AUTHOR]

UPP1, a crucial pyrimidine metabolism-related enzyme, catalyzes the reversible phosphorylation of uridine to uracil and ribose-1-phosphate. However, the effects of UPP1 in bladder cancer (BLCA) have not been elucidated. AKT, which is activated mainly through dual phosphorylation (Thr308 and Ser473), promotes tumorigenesis by phosphorylating downstream substrates. This study demonstrated that UPP1 promotes BLCA cell proliferation, migration, invasion, and gemcitabine resistance by activating the AKT signaling pathway in vitro and in vivo . Additionally, UPP1 promoted AKT activation by facilitating the binding of AKT to PDK1 and PDK2 and the recruitment of phosphatidylinositol 3,4,5-triphosphate to AKT. Moreover, the beneficial effects of UPP1 on BLCA tumorigenesis were mitigated upon UPP1 mutation with Arg94 or MK2206 treatment (AKT-specific inhibitor). AKT overexpression or SC79 (AKT-specific activator) treatment restored tumor malignancy and drug resistance. Thus, this study revealed that UPP1 is a crucial oncogene and a potential therapeutic target for BLCA and that UPP1 activates the AKT signaling pathway and enhances tumorigenesis and drug resistance to gemcitabine., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The 5-fluorouracil (5FU)-based adjuvant chemotherapy improves the survival of patients with colorectal cancer, however the main obstacle affecting its effectiveness is a drug resistance. Our study aimed to investigate the impact of TWIST1 silencing on the sensitivity of cancer cells to 5FU. The suppression of TWIST1 expression in human colon cancer HT29 and HCT116 cell lines was achieved by transduction with lentiviral vector carrying the TWIST1 silencing sequence (pLL3.7-sh TWIST1 ). The suppression of TWIST1 expression induced changes in the expression pattern of epithelial to mesenchymal transition markers, reduced the cells proliferation rate, increased their sensitivity to serum withdrawn, and increased the cytotoxic effect of 5FU. However, significantly higher 5FU cytotoxicity was observed in HT29 cell cultures. Cells with silenced TWIST1 displayed altered expression of enzymes metabolizing 5FU. The expression level of dihydropyrimidine dehydrogenase, and thymidylate synthase decreased significantly in HT29 sh TWIST1 cells, but not in HCT116 sh TWIST1 cells. On the other hand, significant increases in the expression levels of thymidine phosphorylase, and uridine phosphorylase 1 were seen in both cell lines with suppressed expression of TWIST1 . The changes in enzymes expression were mirrored by enzymatic activities. In conclusion, our observations point to TWIST1 as a target protein to enhance the sensitivity of colorectal cancer cells to 5FU. [ABSTRACT FROM AUTHOR]