UDP-α-D-glucose 6-dehydrogenase: a promising target for glioblastoma

Peripheral serum iTRAQ-based proteomic characteristics of carbon tetrachloride-induced acute liver injury in Macaca fascicularis

Carbon tetrachloride (CCl4) is a potent chemical compound that can induce liver cells necrosis. The purpose of this study was to evaluate the hepatic toxicity of CCl4 exposure in Macaca fascicularis to explore the liver toxicity mechanism using a proteomic approach. One animal (no.F6) was intoxicated by oral gavage with 15 % CCl4 solution (10 mL/kg, dissolved in edible peanut oil), and was sacrificed at 48 h after CCl4 administration. Another blank control animal (no.F4) was sacrificed at the same time. The liver cells of the blank control animal showed normal hepatocyte morphology. However, the hepatocytes at 48 h time point after CCl4 administration showed necrosis and vacuolation histopathologically. The animal No.F7∼F12 and no.M7∼M12 were administrated by gavage with 15 % CCl4 solution (10 mL/kg, dissolved in edible peanut oil). Blood samples were collected before gavage administration, and served as the 0 h blank control samples. Then, blood samples were collected at 2 h, 48 h, 72 h and 168 h after CCl4 exposure, and served as the test samples. Routine biochemistry and immunical parameters were performed using biochemistry analyzer for all serum. Then the serum from male and female animals at 0 h, 2 h, 48 h, and 72 h was mixed, respectively. The peripheral serum proteins at 0 h, 2 h, 48 h, and 72 h were extracted, then the proteins were enzymatically hydrolyzed and the peptides were isotopic labeled by isobaric tags for relative and absolute quantification (iTRAQ). Finally, the UniProt Protein Sequence Library of Macaca fascicularis was queried to identify and compare the differential proteins between different time points. The results showed that, as traditional biomarkers of liver injury, alanine aminotransferases (ALT) and aspartate aminotransferases (AST) showed a typical time-effect curve. Compared with 0 h, there were totally 55, 323, and 158 differential proteins (P value <0.05, Ratio fold >1.5, FDR<0.05) at 2 h, 48 h and 72 h, respectively. GO enrichment analysis of differentially expressed proteins only at 48 h involved 3 cellular components (P adjust value <0.05), and differential proteins at other time points had no significant enrichment. Furthermore, KEGG enrichment analysis showed that the toxicity effect of CCl4 at different time points after administration was mediated through 22 pathways such as biosynthesis of antibiotics, carbon metabolism, biosynthesis of amino acids, peroxisome, cysteine and methionine metabolism, arginine biosynthesis, and complement and coagulation cascades (P adjust value <0.05). Among them, the counts of signaling pathway involved biosynthesis of antibiotics, carbon metabolism and biosynthesis of amino acids were more than 10 and the three pathways may play a greater role in toxicity progress after administration of CCl4. PPI network analysis showed that there were 3, 52, and 13 nodes in the interaction of differential proteins at 2 h, 48 h, and 72 h, respectively. In conclusion, many differential proteins in peripheral blood were detected after CCl4 administration, and the GO and KEGG enrichment analysis showed the toxicological mechanisms of CCl4-induced liver injury and potential protection reaction mechanism for CCl4 detoxication may be related with multi biological processes, signaling pathway and targets.

UGDH promotes tumor-initiating cells and a fibroinflammatory tumor microenvironment in ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is a global health burden, with the poorest five-year survival rate of the gynecological malignancies due to diagnosis at advanced stage and high recurrence rate. Recurrence in EOC is driven by the survival of chemoresistant, stem-like tumor-initiating cells (TICs) that are supported by a complex extracellular matrix and immunosuppressive microenvironment. To target TICs to prevent recurrence, we identified genes critical for TIC viability from a whole genome siRNA screen. A top hit was the cancer-associated, proteoglycan subunit synthesis enzyme UDP-glucose dehydrogenase (UGDH).

METHODS

Immunohistochemistry was used to characterize UGDH expression in histological and molecular subtypes of EOC. EOC cell lines were subtyped according to the molecular subtypes and the functional effects of modulating UGDH expression in vitro and in vivo in C1/Mesenchymal and C4/Differentiated subtype cell lines was examined.

RESULTS

High UGDH expression was observed in high-grade serous ovarian cancers and a distinctive survival prognostic for UGDH expression was revealed when serous cancers were stratified by molecular subtype. High UGDH was associated with a poor prognosis in the C1/Mesenchymal subtype and low UGDH was associated with poor prognosis in the C4/Differentiated subtype. Knockdown of UGDH in the C1/mesenchymal molecular subtype reduced spheroid formation and viability and reduced the CD133 + /ALDH high TIC population. Conversely, overexpression of UGDH in the C4/Differentiated subtype reduced the TIC population. In co-culture models, UGDH expression in spheroids affected the gene expression of mesothelial cells causing changes to matrix remodeling proteins, and fibroblast collagen production. Inflammatory cytokine expression of spheroids was altered by UGDH expression. The effect of UGDH knockdown or overexpression in the C1/ Mesenchymal and C4/Differentiated subtypes respectively was tested on mouse intrabursal xenografts and showed dynamic changes to the tumor stroma. Knockdown of UGDH improved survival and reduced tumor burden in C1/Mesenchymal compared to controls.

CONCLUSIONS

These data show that modulation of UGDH expression in ovarian cancer reveals distinct roles for UGDH in the C1/Mesenchymal and C4/Differentiated molecular subtypes of EOC, influencing the tumor microenvironmental composition. UGDH is a strong potential therapeutic target in TICs, for the treatment of EOC, particularly in patients with the mesenchymal molecular subtype.

UDP-glucose dehydrogenase expression is upregulated following EMT and differentially affects intracellular glycerophosphocholine and acetylaspartate levels in breast mesenchymal cell lines

Metabolic rewiring is one of the indispensable drivers of epithelial-mesenchymal transition (EMT) involved in breast cancer metastasis. In this study, we explored the metabolic changes during spontaneous EMT in three separately established breast EMT cell models using a proteomics approach supported by metabolomic analysis. We identified common proteomic changes, including in the expression of CDH1, CDH2, VIM, LGALS1, SERPINE1, PKP3, ATP2A2, JUP, MTCH2, RPL26L1 and PLOD2. Consistently altered metabolic enzymes included: FDFT1, SORD, TSTA3 and UDP-glucose dehydrogenase (UGDH). Of these, UGDH was most prominently altered and has previously been associated with breast cancer patient survival. siRNA-mediated knockdown of UGDH resulted in delayed cell proliferation and dampened invasive potential of mesenchymal cells, and downregulated expression of the EMT transcription factor SNAI1. Metabolomic analysis revealed that siRNA-mediated knockdown of UGDH decreased intracellular glycerophosphocholine (GPC), whereas levels of acetylaspartate (NAA) increased. Finally, our data suggested that platelet-derived growth factor receptor beta (PDGFRB) signaling was activated in mesenchymal cells. siRNA-mediated knockdown of PDGFRB downregulated UGDH expression, potentially via NFkB-p65. Our results support an unexplored relationship between UGDH and GPC, both of which have previously been independently associated with breast cancer progression.

Targeting Pyrimidine Metabolism in the Era of Precision Cancer Medicine

Metabolic rewiring is considered as a primary feature of cancer. Malignant cells reprogram metabolism pathway in response to various intrinsic and extrinsic drawback to fuel cell survival and growth. Among the complex metabolic pathways, pyrimidine biosynthesis is conserved in all living organism and is necessary to maintain cellular fundamental function (i.e. DNA and RNA biosynthesis). A wealth of evidence has demonstrated that dysfunction of pyrimidine metabolism is closely related to cancer progression and numerous drugs targeting pyrimidine metabolism have been approved for multiple types of cancer. However, the non-negligible side effects and limited efficacy warrants a better strategy for negating pyrimidine metabolism in cancer. In recent years, increased studies have evidenced the interplay of oncogenic signaling and pyrimidine synthesis in tumorigenesis. Here, we review the recent conceptual advances on pyrimidine metabolism, especially dihydroorotate dehydrogenase (DHODH), in the framework of precision oncology medicine and prospect how this would guide the development of new drug precisely targeting the pyrimidine metabolism in cancer.