Evaluation of biomass sources on the production of biofuels from lignocellulosic waste over zeolite catalysts.

Catalytic fast pyrolysis (CFP) is a promising method to convert biomass waste into sustainable bio-oils. However, the relationship gap between biomass characteristics and bio-oil quality has hindered the development of CFP technology. This study investigated the pyrolysis and CFP of ten biomass sources over zeolites, and showed that biomass sources and zeolites played important roles in bio-oil production. For noncatalytic trials, the bio-oil yield was positively related to holocellulose (R2 = 0.75) and volatiles content (R2 = 0.62) but negatively to ash content (R2 = -0.65). The bio-oil quality was dramatically improved after catalyst addition. For CFP over ZSM-5, hydrocarbons selectivity of bio-oils was increased by 1.6∼79.3 times, which was closely related to H/C ratio (R2 = 0.79). For ZSM-5@SBA-15 trials, the dependency of hydrocarbons selectivity on biomass characteristics was less clear than that in ZSM-5 counterparts, although undesirable PAHs were inhibited for most biomass sources. This study demonstrated the influence mechanism of biomass characteristics on bio-oil compositions.

AuNPs/CNC Nanocomposite with A "Dual Dispersion" Effect for LDI-TOF MS Analysis of Intact Proteins in NSCLC Serum Exosomes.

Detecting exosomal markers using laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) is a novel approach for examining liquid biopsies of non-small cell lung cancer (NSCLC) samples. However, LDI-TOF MS is limited by low sensitivity and poor reproducibility when analyzing intact proteins directly. In this report, gold nanoparticles/cellulose nanocrystals (AuNPs/CNC) is introduced as the matrix for direct analysis of intact proteins in NSCLC serum exosomes. AuNPs/CNC with "dual dispersion" effects dispersed and stabilized AuNPs and improved ion inhibition effects caused by protein aggregation. These features increased the signal-to-noise ratio of [M+H]+ peaks by two orders of magnitude and lowered the detection limit of intact proteins to 0.01 mg mL-1. The coefficient of variation with or without AuNPs/CNC is measured as 10.2% and 32.5%, respectively. The excellent reproducibility yielded a linear relationship (y = 15.41x - 7.983, R2 = 0.989) over the protein concentration range of 0.01 to 20 mg mL-1. Finally, AuNPs/CNC-assisted LDI-TOF MS provides clinically relevant fingerprint information of exosomal proteins in NSCLC serum, and characteristic proteins S100 calcium-binding protein A10, Urokinase plasminogen activator surface receptor, Plasma protease C1 inhibitor, Tyrosine-protein kinase Fgr and Mannose-binding lectin associated serine protease 2 represented excellent predictive biomarkers of NSCLC risk.

PAR-CLIP Assay in Ferroptosis.

Ferroptosis is a regulatory cell death process that is accompanied by large amounts of iron ion accumulation and lipid peroxidation. Photoactivated ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) is a method used to identify the binding sites of RNA-binding proteins (RBPs) on target RNAs with high resolution at the nucleotide level. By inserting photosensitive ribonucleoside analogs into new RNA transcripts of living cells, characteristic mutations can be generated during reverse transcription and be used to accurately locate the crosslinking position of RNAs and RBPs. The use of PAR-CLIP to detect interactions and determine precise crosslinking sites between RNAs and RBPs, or to search for RNAs upstream or downstream of ferroptosis pathways genes through known proteins, can help to clarify and verify the occurrence and regulation mechanisms of the various signaling pathways of ferroptosis. Furthermore, it may reveal new targets for ferroptosis detection and improve the treatment efficiency of ferroptosis-related diseases such as cancer and neurodegenerative diseases. Here, we introduce a specific PAR-CLIP protocol for monitoring the ferroptosis process.

NMT1 sustains ICAM-1 to modulate adhesion and migration of tumor cells.

Protein modifications have significant effects on tumorigenesis. N-Myristoylation is one of the most important lipidation modifications, and N-myristoyltransferase 1 (NMT1) is the main enzyme required for this process. However, the mechanism underlying how NMT1 modulates tumorigenesis remains largely unclear. Here, we found that NMT1 sustains cell adhesion and suppresses tumor cell migration. Intracellular adhesion molecule 1 (ICAM-1) was a potential functional downstream effector of NMT1, and its N-terminus could be N-myristoylated. NMT1 prevented ubiquitination and proteasome degradation of ICAM-1 by inhibiting Ub E3 ligase F-box protein 4, which prolonged the half-life of ICAM-1 protein. Correlations between NMT1 and ICAM-1 were observed in liver and lung cancers, which were associated with metastasis and overall survival. Therefore, carefully designed strategies focusing on NMT1 and its downstream effectors might be helpful to treat tumors.

IGF2BP3 is an essential N6-methyladenosine biotarget for suppressing ferroptosis in lung adenocarcinoma cells.

A lack of promising targets leads to poor prognosis in patients with lung adenocarcinoma (LUAD). Therefore, it is urgent to identify novel therapeutic targets. The importance of the N6-methyladenosine (m6A) RNA modification has been demonstrated in various types of tumors; however, knowledge of m6A-related proteins in LUAD is still limited. Here, we found that insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), an m6A reader protein, is highly expressed in LUAD and associated with poor prognosis. IGF2BP3 desensitizes ferroptosis (a new form of regulated cell death) in a manner dependent on its m6A reading domain and binding capacity to m6A-methylated mRNAs encoding anti-ferroptotic factors, including but not limited to glutathione peroxidase 4 (GPX4), solute carrier family 3 member 2 (SLC3A2), acyl-CoA synthetase long chain family member 3 (ACSL3), and ferritin heavy chain 1 (FTH1). After IGF2BP3 overexpression, expression levels and mRNA stabilities of these anti-ferroptotic factors were successfully sustained. Notably, significant correlations between SLC3A2, ACSL3, and IGF2BP3 were revealed in clinical LUAD specimens, further establishing the essential role of IGF2BP3 in desensitizing ferroptosis. Inducing ferroptosis has been gradually accepted as an alternative strategy to treat tumors. Thus, IGF2BP3 could be a potential target for the future development of new biomaterial-associated therapeutic anti-tumor drugs.

Essential roles of exosome and circRNA_101093 on ferroptosis desensitization in lung adenocarcinoma.

BACKGROUND: Resistance to ferroptosis, a regulated cell death caused by iron-dependent excessive accumulation of lipid peroxides, has recently been linked to lung adenocarcinoma (LUAD). Intracellular antioxidant systems are required for protection against ferroptosis. The purpose of the present study was to investigate whether and how extracellular system desensitizes LUAD cells to ferroptosis. METHODS: Established human lung fibroblasts MRC-5, WI38, and human LUAD H1650, PC9, H1975, H358, A549, and H1299 cell lines, tumor and matched normal adjacent tissues of LUAD, and plasma from healthy individuals and LUAD patients were used in this study. Immunohistochemistry and immunoblotting were used to analyze protein expression, and quantitative reverse transcription-PCR was used to analyze mRNA expression. Cell viability, cell death, and the lipid reactive oxygen species generation were measured to evaluate the responses to ferroptosis. Exosomes were observed using transmission electron microscope. The localization of arachidonic acid (AA) was detected using click chemistry labeling followed by confocal microscopy. Interactions between RNAs and proteins were detected using RNA pull-down, RNA immunoprecipitation and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation methods. Proteomic analysis was used to investigate RNA-regulated proteins, and metabolomic analysis was performed to analyze metabolites. Cell-derived xenograft, patient-derived xenograft, cell-implanted intrapulmonary LUAD mouse models and plasma/tissue specimens from LUAD patients were used to validate the molecular mechanism. RESULTS: Plasma exosome from LUAD patients specifically reduced lipid peroxidation and desensitized LUAD cells to ferroptosis. A potential explanation is that exosomal circRNA_101093 (cir93) maintained an elevation in intracellular cir93 in LUAD to modulate AA, a poly-unsaturated fatty acid critical for ferroptosis-associated increased peroxidation in the plasma membrane. Mechanistically, cir93 interacted with and increased fatty acid-binding protein 3 (FABP3), which transported AA and facilitated its reaction with taurine. Thus, global AA was reduced, whereas N-arachidonoyl taurine (NAT, the product of AA and taurine) was induced. Notably, the role of NAT in suppressing AA incorporation into the plasma membrane was also revealed. In pre-clinical in vivo models, reducing exosome improved ferroptosis-based treatment. CONCLUSION: Exosome and cir93 are essential for desensitizing LUAD cells to ferroptosis, and blocking exosome may be helpful for future LUAD treatment.

Tumour cells are sensitised to ferroptosis via RB1CC1-mediated transcriptional reprogramming.

BACKGROUND: Ferroptosis, a form of regulated cell death, is an important topic in the field of cancer research. However, the signalling pathways and factors that sensitise tumour cells to ferroptosis remain elusive. METHODS: We determined the level of ferroptosis in cells by measuring cell death and lipid reactive oxygen species (ROS) production. The expression of RB1-inducible coiled-coil 1 (RB1CC1) and related proteins was analyzed by immunoblotting and immunohistochemistry. Immunofluorescence was used to determine the subcellular localization of RB1CC1. We investigated the mechanism of RB1CC1 nuclear translocation by constructing a series of RB1CC1 variants. To examine the ferroptosis- and RB1CC1-dependent transcriptional program in tumour cells, chromatin immunoprecipitation sequencing was performed. To assess the effect of c-Jun N-terminal kinase (JNK) agonists on strenthening imidazole ketone erastin (IKE) therapy, we constructed cell-derived xenograft mouse models. Mouse models of hepatocellular carcinoma to elucidate the importance of Rb1cc1 in IKE-based therapy of liver tumourigenesis. RESULTS: RB1CC1 is upregulated by lipid ROS and that nuclear translocation of phosphorylation of RB1CC1 at Ser537 was essential for sensitising ferroptosis in tumour cells. Upon ferroptosis induction, nuclear RB1CC1 sharing forkhead box (FOX)-binding motifs recruits elongator acetyltransferase complex subunit 3 (ELP3) to strengthen H4K12Ac histone modifications within enhancers linked to ferroptosis. This also stimulated transcription of ferroptosis-associated genes, such as coiled-coil-helix-coiled-coil-helix domain containing 3 (CHCHD3), which enhanced mitochondrial function to elevate mitochondrial ROS early following induction of ferroptosis. FDA-approved JNK activators reinforced RB1CC1 nuclear translocation and sensitised cells to ferroptosis, which strongly suggested that JNK is upstream of RB1CC1. Nuclear localisation of RB1CC1 correlated with lipid peroxidation in clinical lung cancer specimens. Rb1cc1 was essential for ferroptosis agonists to suppress liver tumourigenesis in mice. CONCLUSIONS: Our findings indicate that RB1CC1-associated signalling sensitises tumour cells to ferroptosis and that targeting RB1CC1 may be beneficial for tumour treatment.

YAP ISGylation increases its stability and promotes its positive regulation on PPP by stimulating 6PGL transcription.

Yes-associated protein (YAP) activation is crucial for tumor formation and development, and its stability is regulated by ubiquitination. ISGylation is a type of ubiquitination like post-translational modification, whereas whether YAP is ISGylated and how ISGylation influences YAP ubiquitination-related function remains uncovered. In addition, YAP can activate glucose metabolism by activating the hexosamine biosynthesis pathway (HBP) and glycolysis, and generate a large number of intermediates to promote tumor proliferation. However, whether YAP stimulates the pentose phosphate pathway (PPP), another tumor-promoting glucose metabolism pathway, and the relationship between this stimulation and ISGylation needs further investigation. Here, we found that YAP was ISGylated and this ISGylation inhibited YAP ubiquitination, proteasome degradation, interaction with-beta-transducin repeat containing E3 ubiquitin-protein ligase (ßTrCP) to promote YAP stability. However, ISGylation-induced pro-YAP effects were abolished by YAP K497R (K, lysine; R, arginine) mutation, suggesting K497 could be the major YAP ISGylation site. In addition, YAP ISGylation promoted cell viability, cell-derived xenograft (CDX) and patient-derived xenograft (PDX) tumor formation. YAP ISGylation also increased downstream genes transcription, including one of the key enzymes of PPP, 6-phosphogluconolactonase (6PGL). Mechanistically, YAP promoted 6PGL transcription by simultaneously recruiting SMAD family member 2 (SMAD2) and TEA domain transcription factor 4 (TEAD4) binding to the 6PGL promoter to activate PPP. In clinical lung adenocarcinoma (LUAD) specimens, we found that YAP ISGylation degree was positively associated with 6PGL mRNA level, especially in high glucose LUAD tissues compared to low glucose LUAD tissues. Collectively, this study suggested that YAP ISGylation is critical for maintaining its stability and further activation of PPP. Targeting ISGylated YAP might be a new choice for hyperglycemia cancer treatment.

The essential roles of m6A RNA modification to stimulate ENO1-dependent glycolysis and tumorigenesis in lung adenocarcinoma.

BACKGROUND: Lung adenocarcinoma (LUAD)  is the most common subtype of lung cancer. Patient prognosis is poor, and the existing therapeutic strategies for LUAD are far from satisfactory. Recently, targeting N6-methyladenosine (m6A) modification of RNA has been suggested as a potential strategy to impede tumor progression. However, the roles of m6A modification in LUAD tumorigenesis is unknown. METHODS: Global m6A levels and expressions of m6A writers, erasers and readers were evaluated by RNA methylation assay, dot blot, immunoblotting, immunohistochemistry and ELISA in human LUAD, mouse models and cell lines. Cell viability, 3D-spheroid generation, in vivo LUAD formation, experiments in cell- and patient-derived xenograft mice and survival analysis were conducted to explore the impact of m6A on LUAD. The RNA-protein interactions, translation, putative m6A sites and glycolysis were explored in the investigation of the mechanism underlying how m6A stimulates tumorigenesis. RESULTS: The elevation of global m6A level in most human LUAD specimens resulted from the combined upregulation of m6A writer methyltransferase 3 (METTL3) and downregulation of eraser alkB homolog 5 (ALKBH5). Elevated global m6A level was associated with a poor overall survival in LUAD patients. Reducing m6A levels by knocking out METTL3 and overexpressing ALKBH5 suppressed 3D-spheroid generation in LUAD cells and intra-pulmonary tumor formation in mice. Mechanistically, m6A-dependent stimulation of glycolysis and tumorigenesis occurred via enolase 1 (ENO1). ENO1 mRNA was m6A methylated at 359 A, which facilitated it's binding with the m6A reader YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) and resulted in enhanced translation of ENO1. ENO1 positively correlated with METTL3 and global m6A levels, and negatively correlated with ALKBH5 in human LUAD. In addition, m6A-dependent elevation of ENO1 was associated with LUAD progression. In preclinical models, tumors with a higher global m6A level showed a more sensitive response to the inhibition of pan-methylation, glycolysis and ENO activity in LUAD. CONCLUSIONS: The m6A-dependent stimulation of glycolysis and tumorigenesis in LUAD is at least partially orchestrated by the upregulation of METTL3, downregulation of ALKBH5, and stimulation of YTHDF1-mediated ENO1 translation. Blocking this mechanism may represent a potential treatment strategy for m6A-dependent LUAD.

TRIB2 desensitizes ferroptosis via ßTrCP-mediated TFRC ubiquitiantion in liver cancer cells.

Tribbles homolog 2 (TRIB2) is known to boost liver tumorigenesis via regulating Ubiquitin (Ub) proteasome system (UPS). At least two ways are involved, i.e., acts as an adaptor protein to modulate ubiquitination functions of certain ubiquitin E3 ligases (E3s) and reduces global Ub levels via increasing the proteolysis activity of proteasome. Recently, we have identified the role of TRIB2 to relieve oxidative damage via reducing the availability of Ub that is essential for the ubiquitination and subsequent degradation of Glutathione peroxidase 4 (GPX4). Although GPX4 is a critical antioxidant factor to protect against ferroptosis, the exact evidence showing that TRIB2 desensitizes ferroptosis is lacking. Also, whether such function is via E3 remains unclear. Here, we demonstrated that deletion of TRIB2 sensitized ferroptosis via lifting labile iron in liver cancer cells. By contrast, overexpression of TRIB2 led to the opposite outcome. We further demonstrated that transferrin receptor (TFRC) was required for TRIB2 to desensitize the cells to ferroptosis. Without TFRC, the labile iron pool could not be reduced by overexpressing TRIB2. We also found that beta-transducin repeat containing E3 ubiqutin protein ligase (ßTrCP) was a genuine E3 for the ubiquitination of TFRC, and TRIB2 was unable to decline labile iron level once upon ßTrCP was knocked out. In addition, we confirmed that the opposite effects on ferroptosis and ferroptosis-associated lipid reactive oxygen species (ROS) generation resulted from knockout and overexpression of TRIB2 were all indispensible of TFRC and ßTrCP. Finally, we demonstrated that TRIB2 exclusively manipulated RSL3- and erastin-induced-ferroptosis independent of GPX4 and glutathione (GSH). In conclusion, we elucidated a novel role of TRIB2 to desensitize ferroptosis via E3 ßTrCP, by which facilitates TFRC ubiquitiation and finally decreases labile iron in liver cancer cells.

N-Myristoylation by NMT1 Is POTEE-Dependent to Stimulate Liver Tumorigenesis via Differentially Regulating Ubiquitination of Targets.

BACKGROUND: A tremendous amount of studies have suggested that post-translational modifications (PTMs) play pivotal roles during tumorigenesis. Compared to other PTMs, lipid modification is less studied. Recently, N-myristoylation, one type of lipid modification, has been paid attention to the field of cancer. However, whether and how N-myristoylation exerts its roles in liver tumorigenesis still remains unclear. METHODS: Parallel reaction monitoring (PRM) was conducted to evaluate the expression of protein modification enzymes in paired tissues. Liver conditionally knocking NMT1 out mice model was used to assess the critical roles of N-myristoylation during liver tumorigenesis. Proteomics isobaric tags for relative and absolute quantification (iTraq) was performed to identify proteins that changed while NMT1 was knocked down. The click chemistry assay was used to evaluate the N-myristoylation levels of proteins. RESULTS: Here, N-myristolyation and its enzyme NMT1, but not NMT2, were found to be critical in liver cancer. Two categories of proteins, i.e., N-myristolyation down-regulated proteins (NDP, including LXN, RPL29, and FAU) and N-myristolyation up-regulated proteins (NUP, including AHSG, ALB, and TF), were revealed negatively and positively regulated by NMT1, respectively. Both NDP and NUP could be N-myristolyated by NMT1 indispensable of POTEE. However, N-myristolyation decreased and increased stability of NDP and NUP, respectively. Mechanistically, NDP-specific binding protein RPL7A facilitated HIST1H4H, which has ubiquitin E3 ligase function, to ubiquitinate NDP. By contrast, NUP-specific binding protein HBB prevented NUP from ubiquitination by HIST1H4H. Notably, function of RPL7A and HBB was all NMT1-dependent. Moreover, NDP suppressed while NUP stimulated transformative phenotypes. Clinically, higher levels of NMT1 and NUP with lower levels of NDP had worse prognostic outcome. CONCLUSION: Collectively, N-myristolyation by NMT1 suppresses anti-tumorigenic NDP, whereas it stimulates pro-tumorigenic NUP by interfering their ubiquitination to finally result in a pro-tumorigenic outcome in liver cancer. Targeting N-myristolyation and NMT1 might be helpful to treat liver cancer.

Endogenous glutamate determines ferroptosis sensitivity via ADCY10-dependent YAP suppression in lung adenocarcinoma.

Rationale: Ferroptosis, a newly identified form of regulated cell death, can be induced following the inhibition of cystine-glutamate antiporter system XC- because of the impaired uptake of cystine. However, the outcome following the accumulation of endogenous glutamate in lung adenocarcinoma (LUAD) has not yet been determined. Yes-associated protein (YAP) is sustained by the hexosamine biosynthesis pathway (HBP)-dependent O-linked beta-N-acetylglucosaminylation (O-GlcNAcylation), and glutamine-fructose-6-phosphate transaminase (GFPT1), the rate-limiting enzyme of the HBP, can be phosphorylated and inhibited by adenylyl cyclase (ADCY)-mediated activation of protein kinase A (PKA). However, whether accumulated endogenous glutamate determines ferroptosis sensitivity by influencing the ADCY/PKA/HBP/YAP axis in LUAD cells is not understood. Methods: Cell viability, cell death and the generation of lipid reactive oxygen species (ROS) and malondialdehyde (MDA) were measured to evaluate the responses to the induction of ferroptosis following the inhibition of system XC-. Tandem mass tags (TMTs) were employed to explore potential factors critical for the ferroptosis sensitivity of LUAD cells. Immunoblotting (IB) and quantitative RT-PCR (qPCR) were used to analyze protein and mRNA expression. Co-immunoprecipitation (co-IP) assays were performed to identify protein-protein interactions and posttranslational modifications. Metabolite levels were measured using the appropriate kits. Transcriptional regulation was evaluated using a luciferase reporter assay, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA). Drug administration and limiting dilution cell transplantation were performed with cell-derived xenograft (CDX) and patient-derived xenograft (PDX) mouse models. The associations among clinical outcome, drug efficacy and ADCY10 expression were determined based on data from patients who underwent curative surgery and evaluated with patient-derived primary LUAD cells and tissues. Results: The accumulation of endogenous glutamate following system XC- inhibition has been shown to determine ferroptosis sensitivity by suppressing YAP in LUAD cells. YAP O-GlcNAcylation and expression cannot be sustained in LUAD cells upon impairment of GFPT1. Thus, Hippo pathway-like phosphorylation and ubiquitination of YAP are enhanced. ADCY10 acts as a key downstream target and diversifies the effects of glutamate on the PKA-dependent suppression of GFPT1. We also discovered that the protumorigenic and proferroptotic effects of ADCY10 are mediated separately. Advanced-stage LUADs with high ADCY10 expression are sensitive to ferroptosis. Moreover, LUAD cells with acquired therapy resistance are also prone to higher ADCY10 expression and are more likely to respond to ferroptosis. Finally, a varying degree of secondary labile iron increase is caused by the failure to sustain YAP-stimulated transcriptional compensation for ferritin at later stages further explains why ferroptosis sensitivity varies among LUAD cells. Conclusions: Endogenous glutamate is critical for ferroptosis sensitivity following the inhibition of system XC- in LUAD cells, and ferroptosis-based treatment is a good choice for LUAD patients with later-stage and/or therapy-resistant tumors.

TRIB2 modulates proteasome function to reduce ubiquitin stability and protect liver cancer cells against oxidative stress.

The regulation of homeostasis in the Ubiquitin (Ub) proteasome system (UPS) is likely to be important for the development of liver cancer. Tribbles homolog 2 (TRIB2) is known to affect Ub E3 ligases (E3s) in liver cancer. However, whether TRIB2 regulates the UPS in other ways and the relevant mechanisms are still unknown. Here, we reveal that TRIB2 decreased Ub levels largely by stimulating proteasome degradation of Ub. In the proteasome, proteasome 20S subunit beta 5 (PSMB5) was critical for the function of TRIB2, although it did not directly interact with TRIB2. However, poly (rC) binding protein 2 (PCBP2), which was identified by mass spectrometry, directly interacted with both TRIB2 and PSMB5. PCBP2 was a prerequisite for the TRIB2 induction of PSMB5 activity and decreased Ub levels. A significant correlation between TRIB2 and PCBP2 was revealed in liver cancer specimens. Interestingly, TRIB2 suppressed the K48-ubiquitination of PCBP2 to increase its level. Therefore, a model showing that TRIB2 cooperates and stimulates PCBP2 to reduce Ub levels was established. Additionally, the reduction in Ub levels induced by TRIB2 and PCBP2 was dependent on K48-ubiquitination. PCBP2 was one of the possible downstream factors of TRIB2 and their interaction relied on the DQLVPD element of TRIB2 and the KH3 domain of PCBP2. This interaction was necessary to maintain the viability of the liver cancer cells and promote tumor growth. Mechanistically, glutathione peroxidase 4 functioned as one of the terminal effectors of TRIB2 and PCBP2 to protect liver cancer cells from oxidative damage. Taken together, the data indicate that, in addition to affecting E3s, TRIB2 plays a critical role in regulating UPS by modulating PSMB5 activity in proteasome to reduce Ub flux, and that targeting TRIB2 might be helpful in liver cancer treatments by enhancing the oxidative damage induced by therapeutic agents.

RRM2 protects against ferroptosis and is a tumor biomarker for liver cancer.

BACKGROUND: Ferroptosis is the process of cell death triggered by lipid peroxides, and inhibition of glutathione (GSH) synthesis leads to ferroptosis. Liver cancer progression is closely linked to ferroptosis suppression. However, the mechanism by which inhibition of GSH synthesis suppresses potential ferroptosis of liver cancer cells and whether ferroptosis-related liver cancer biomarkers have a promising diagnostic value remain unknown. METHODS: Ribonucleotide reductase regulatory subunit M2 (RRM2) levels were measured using an enzyme linked immunosorbent assay (ELISA), quantitative RT-PCR (qPCR), immunoblotting (IB) and immunochemistry (IHC). Cell viability and cell death were measured by a CellTiter-Glo luminescent cell viability assay and staining with SYTOX Green followed by flow cytometry, respectively. Metabolites were measured using the indicated kits. The Interaction between glutathione synthetase (GSS) and RRM2 was measured using immunofluorescence (IF), co-immunoprecipitation (co-IP) and the proximal ligation assay (PLA). The diagnostic value was analyzed using the area under the receiver operating characteristic curve (AUC-ROC). Bioinformatics analysis was performed using the indicated database. RESULTS: RRM2 showed specifically elevated levels in liver cancer and inhibited ferroptosis by stimulating GSH synthesis via GSS. Mechanistically, phosphorylation of RRM2 at the Threonine 33 residue (T33) was maintained at normal levels to block the RRM2-GSS interaction and therefore protected RRM2 and GSS from further proteasome degradation. However, under ferroptotic stress, RRM2 was dephosphorylated at T33, thus the RRM2-GSS interaction was promoted. This resulted in the translocation of RRM2 and GSS to the proteasome for simultaneous degradation. Clinically, serum RRM2 was significantly associated with serum alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma glutamyl transpeptidase (γ-GT), albumin (ALB) and total bilirubin. The AUC-ROC for the combination of RRM2 with AFP was 0.947, with a sensitivity of 88.7% and a specificity of 97.0%, which indicates better diagnostic performance compared to either RRM2 or AFP alone. CONCLUSION: RRM2 exerts an anti-ferroptotic role in liver cancer cells by sustaining GSH synthesis. Serum RRM2 will be useful as a biomarker to evaluate the degree to which ferroptosis is suppressed and improve diagnostic efficiency for liver cancer.

Catalytic pyrolysis of poplar sawdust: Excellent hydrocarbon selectivity and activity of hollow zeolites.

Hollow zeolites were investigated for catalytic fast pyrolysis (CFP) of biomass to produce hydrocarbon-rich bio-oil. A series of hollow ZSM-5 catalysts were synthesized via a dissolution-recrystallization strategy. The physicochemical properties of the catalysts were investigated by high-resolution transmission electron microscopy, N2 sorption, X-ray photoelectron spectroscopy, and ammonia temperature-programmed desorption experiments. The hollow zeolite was effective for increasing the hydrocarbon fraction in bio-oil. In particular, hollow HS-ZSM-5(50) afforded the highest hydrocarbon yield (6.8 wt%), which was ~3 times of that achieved with solid ZSM-5(50). The hollowness, acidity, and the presence of secondary wall mesopores in the hollow zeolite were found to affect bio-oil production. The hollow regions stabilized more active biomass intermediates and inhibited their repolymerization to coke, while the interior acid sites continually converted these intermediates to aromatic hydrocarbons. Secondary wall mesopores compromise the hollow space and hinder consecutive catalysis, resulting in phenols as the main product.

miR-1305 Inhibits The Progression Of Non-Small Cell Lung Cancer By Regulating MDM2.

BACKGROUND: Increasing evidence has suggested the critical implication of microRNAs (miRNAs) in the initiation and progression of non-small cell lung cancer (NSCLC). Previous studies have shown the tumor-suppressive function of miR-1305 in cancer; however, the role of miR-1305 in NSCLC has not been fully understood. METHODS: The expression of miR-1305 in NSCLC was detected by RT-qPCR. The influence of miR-1305 on the growth of NSCLC cells was determined via Cell Counting Kit 8 (CCK-8), colony formation and FACS analysis. The targets of miR-1305 were predicted with the miRDB database. Luciferase reporter assay was performed to investigate the binding between miR-1305 and 3'-UTR of MDM2. Western blot was applied to check the expression of MDM2 with miR-1305. RESULTS: Here, we found that miR-1305 was down-regulated in NSCLC tissues and cell lines. Decreased miR-1305 was significantly correlated with the metastasis and poor prognostics of NSCLC patients. Overexpression of miR-1305 inhibited the proliferation and migration and promoted the apoptosis of NSCLC cells. Bioinformatics and luciferase assay uncovered that the mouse/murine double minute 2 (MDM2) was a target of miR-1305. miR-1305 bound the 3'-untranslated region (UTR) of MDM2 and decreased the expression of MDM2 in NSCLC cells. As MDM2 was a negative regulator of p53, decreased MDM2 by miR-1305 up-regulated the abundance of p53 in NSCLC cells. Restoration of MDM2 markedly attenuated the suppressive role of miR-1305 in the proliferation and migration of NSCLC cells. CONCLUSION: The findings provided novel mechanism of miR-1305/MDM2 signaling in regulating the progression of NSCLC, suggesting miR-1305 as a promising target for the treatment of NSCLC.

Catalytic fast pyrolysis of maize straw with a core-shell ZSM-5@SBA-15 catalyst for producing phenols and hydrocarbons.

Zeolites have been widely used as catalysts in the catalytic pyrolysis of biomass to produce biofuels and/or bio-based chemicals, which could lead to the replacement of fossil sources by renewable ones. However, conventional zeolites often suffer from diffusion resistance for large intermediate oxygenates. To solve this problem, a micro/mesoporous core-shell composite zeolite ZSM-5@SBA-15 was prepared and employed as a catalyst in the catalytic pyrolysis of maize straw. ZSM-5@SBA-15 was synthesized by crystallizing mesoporous silica on the external surface of ZSM-5 using the triblock copolymer Plunoric P123 as the template. The core-shell and hierarchical structures were verified using PXRD, TEM, and N2 sorption experiments. In the catalytic pyrolysis of maize straw, ZSM-5@SBA-15 significantly enhanced the yield of valuable phenols and hydrocarbons in bio-oil, compared to ZSM-5 and SBA-15. The results demonstrated the potential application of micro@mesoporous core-shell composite zeolites in the catalytic pyrolysis of biomass.