Continuous flow biocatalysis: synthesis of purine nucleoside esters catalyzed by lipase TL IM from Thermomyces lanuginosus.

Purine nucleoside ester is one of the derivatives of purine nucleoside, which has antiviral and anticancer activities. In this work, a continuous flow synthesis of purine nucleoside esters catalyzed by lipase TL IM from Thermomyces lanuginosus was successfully achieved. Various parameters including solvent, reaction temperature, reaction time/flow rate and substrate ratio were investigated. The best yields were obtained with a continuous flow microreactor for 35 min at 50 °C with the substrate ratio of 1 : 5 (nucleosides to vinyl esters) in the solvent of tert-amyl alcohol. 12 products were efficiently synthesized with yields of 78-93%. Here we reported for the first time the use of lipase TL IM from Thermomyces lanuginosus in the synthesis of purine nucleoside esters. The significant advantages of this methodology are a green solvent and mild conditions, a simple work-up procedure and the highly reusable biocatalyst. This research provides a new technique for rapid synthesis of anticancer and antiviral nucleoside drugs and is helpful for further screening of drug activity.

Constructing N-Containing Poly(p-Phenylene) (PPP) Films Through A Cathodic-Dehalogenation Polymerization Method.

Developing the films of N-containing unsubstituted poly(p-phenylene) (PPP) films for diverse applications is significant and highly desirable because the replacement of sp2 C atoms with sp2 N atoms will bring novel properties to the as-prepared polymers. In this research, an electrochemical-dehalogenation polymerization strategy is employed to construct two N-containing PPP films under constant potentials, where 2,5-diiodopyridine (DIPy) and 2,5-dibromopyrazine (DBPz) are used as starting agents. The corresponding polymers are named CityU-23 (for polypyridine) and CityU-24 (for polypyrazine). Moreover, it is found that both polymers can form films in situ on different conductive substrates (i.e., silicon, gold, ITO, and nickel), satisfying potential device fabrication. Furthermore, the as-obtained thin films of CityU-23 and CityU-24 exhibit good performance of alkaline hydrogen evolution reaction with the overpotential of 212.8 and 180.7 mV and the Tafel slope of 157.0 and 122.4 mV dec-1, respectively.

Development of a green, concise synthesis of nicotinamide derivatives catalysed by Novozym® 435 from Candida antarctica in sustainable continuous-flow microreactors.

An increasing number of studies have shown that many nicotinamide derivatives exhibited extensive biological activities, such as anti-inflammatory and antitumor activity. In this paper, a green, concise synthesis of nicotinamide derivatives in sustainable continuous-flow microreactors catalysed by Novozym® 435 from Candida antarctica has been developed. Application of an easily obtainable and reusable lipase in the synthesis of nicotinamide derivatives from methyl nicotinate and amines/benzylamines reacted for 35 min at 50 °C led to high product yields (81.6-88.5%). Environmentally friendly tert-amyl alcohol was applied as a reaction medium. Substantially shorter reaction times as well as a significant increase in the product yield were obtained as compared to the batch process. This innovative approach provides a promising green, efficient and rapid synthesis strategy for pharmaceutical synthesis and further activity research of novel nicotinamide derivatives.

A Metal-Free Helical Covalent Inorganic Polymer: Preparation, Crystal Structure and Optical Properties.

Helical morphologies are widely observed in nature, however, it is very challenging to prepare artificial helical polymers. Especially, precisely understanding the structure information of artificial metal-free helical covalent inorganic polymers via single-crystal X-ray diffraction (SCXRD) analysis is rarely explored. Here, we successfully prepare a novel metal-free helical covalent inorganic polymer ({[Te(C6 H5 )2 ] [PO3 (OH)]}n , named CityU-10) by introducing angular anions (HOPO3 2- ) into traditional tellurium-oxygen chains. The dynamic reversibility of the reaction is realized through the introduction of organic tellurium precursor and the slow hydrolysis of polyphosphoric acid. High-quality and large-size single crystals of CityU-10 have been successfully characterized via SCXRD, where the same-handed helical inorganic polymer chains form a pseudo-two-dimensional layer via multiple hydrogen-bonding interactions. The left-handed layers and right-handed layers alternatively stack together through weak hydrogen bonds to form a three-dimensional supramolecular structure. The single crystals of CityU-10 are found to display promising optical properties with a large birefringence. Our results would offer new guidelines for designing and preparing new crystalline covalent polymers through tellurium-based chemistry.

miR-1/AMPK-Mediated Glucose and Lipid Metabolism under Chronic Hypothermia in the Liver of Freshwater Drum, Aplodinotus grunniens.

Our previous study demonstrated that low temperature could induce hepatic inflammation and suppress the immune and oxidation resistance of freshwater drum. However, the metabolism, especially the glucose and lipid metabolism involved, is poorly studied. To further explore the chronic hypothermia response of freshwater drum, an 8-day hypothermia experiment was conducted at 10 °C to investigate the effect of chronic hypothermia on glucose and lipid metabolism via biochemical and physiological indexes, and metabolic enzyme activities, miRNAs and mRNA-miRNA integrate analysis in the liver. Plasma and hepatic biochemical parameters reveal chronic hypothermia-promoted energy expenditure. Metabolic enzyme levels uncover that glycolysis was enhanced but lipid metabolism was suppressed. Differentially expressed miRNAs induced by hypothermia were mainly involved in glucose and lipid metabolism, programmed cell death, disease, and cancerization. Specifically, KEGG enrichment indicates that AMPK signaling was dysregulated. mRNA-miRNA integrated analysis manifests miR-1 and AMPK, which were actively co-related in the regulatory network. Furthermore, transcriptional expression of key genes demonstrates hypothermia-activated AMPK signaling by miR-1 and subsequently inhibited the downstream glucogenic and glycogenic gene expression and gene expression of fatty acid synthesis. However, glycogenesis was alleviated to the control level while fatty acid synthesis was still suppressed at 8 d. Meanwhile, the gene expressions of glycolysis and fatty acid oxidation were augmented under hypothermia. In conclusion, these results suggest that miR-1/AMPK is an important target for chronic hypothermia control. It provides a theoretical basis for hypothermia resistance on freshwater drum.

TGF-ß Signaling Pathway-Based Model to Predict the Subtype and Prognosis of Head and Neck Squamous Cell Carcinoma.

Background: Although immunotherapy with immune checkpoint therapy has been used to treat head and neck squamous cell carcinoma (HNSCC), response rates and treatment sensitivity remain limited. Recent studies have indicated that transforming growth factor-ß (TGF-ß) may be an important target for novel cancer immunotherapies. Materials and methods: We collected genomic profile data from The Cancer Genome Atlas and Gene Expression Omnibus. The least absolute shrinkage and selection operator method and Cox regression were used to establish a prognostic model. Gene set enrichment analysis was applied to explore biological functions. Tracking of indels by decomposition and subclass mapping algorithms were adopted to evaluate immunotherapy efficiency. Result: We established a seven TGF-ß pathway-associated gene signature with good prediction efficiency. The high-risk score subgroup mainly showed enrichment in tumor-associated signaling such as hypoxia and epithelial-mesenchymal transition (EMT) pathways; This subgroup was also associated with tumor progression. The low-risk score subgroup was more sensitive to immunotherapy and the high-risk score subgroup to cisplatin, erlotinib, paclitaxel, and crizotinib. Conclusion: The TGF-ß pathway signature gene model provides a novel perspective for evaluating effectiveness pre-immunotherapy and may guide further studies of precision immuno-oncology.

miR-30d-5p: A Non-Coding RNA With Potential Diagnostic, Prognostic and Therapeutic Applications.

Cancer is a great challenge facing global public health. Scholars have made plentiful efforts in the research of cancer therapy, but the results are still not satisfactory. In relevant literature, the role of miRNA in cancer has been widely concerned. MicroRNAs (miRNAs) are a non-coding, endogenous, single-stranded RNAs that regulate a variety of biological functions. The abnormal level of miR-30d-5p, a type of miRNAs, has been associated with various human tumor types, including lung cancer, colorectal cancer, esophageal cancer, prostate cancer, liver cancer, cervical cancer, breast cancer and other types of human tumors. This reflects the vital function of miR-30d-5p in tumor prognosis. miR-30d-5p can be identified either as an inhibitor hindering the development of, or a promoter accelerating the occurrence of tumors. In addition, the role of miR-30d-5p in cell proliferation, motility, apoptosis, autophagy, tumorigenesis, and chemoresistance are also noteworthy. The multiple roles of miR-30d-5p in human cancer suggest that it has broad feasibility as a biomarker and therapeutic target. This review describes the connection between miR-30d-5p and the clinical indications of tumors, and summarizes the mechanisms by which miR-30d-5p mediates cancer progression.

A crucial role for the long non-coding RNA CASC11 in the pathogenesis of human cancers.

Long non-coding RNAs (lncRNAs) are non-coding RNAs more than 200 nucleotides in length. Although they do not encode proteins, lncRNAs can regulate gene expression at the transcriptional, post-transcriptional, and epigenetic levels. Emerging data show that lncRNAs are important for tumorigenesis and cancer progression. Cancer susceptibility candidate 11 (CASC11) is a prominent lncRNA that is upregulated in various types of cancers. Moreover, its overexpression correlates with larger tumor size, more advanced cancer stages, cancer metastasis, and poor overall survival for most types of cancer. Functionally, the knockdown of CASC11 can inhibit cell proliferation, invasion, and migration, while enhancing apoptosis through its regulation of gene expression and signaling pathways and its interactions with functional proteins. Here, we discuss the identification, expression, and function of CASC11. Additionally, we discuss the potential roles of CASC11 as a diagnostic biomarker, prognostic biomarker, and therapeutic target in various cancers.

The role and mechanism of HLA complex group 11 in cancer.

HLA is critical in a variety of diseases, including infectious disease and cancer, and has been used for diagnostic differentiation and immunosurveillance of certain diseases. In addition, emerging evidence suggests that the mutations and dysregulation of lncRNAs are essential contributors in cancers. HLA Complex Group 11 (HCG11) located on MHC region is affiliated with the lncRNA class. Studies have shown that HCG11 could serve as a key regulator in lung cancer, prostate cancer, glioma, cervical cancer and hepatocellular carcinoma. In this review, we summarize the accumulated information on the expression and clinical value of HCG11 in different cancer types, discuss its interactions with microRNAs, mRNAs, and proteins, and discover the biological roles and potential mechanisms of HCG11 in a variety of cellular functions, including cell proliferation, apoptosis, migration, and invasion. Further, we emphasize the possible application of HCG11 in treatment, summarize the studies of HCG11 in chemotherapy resistance and hormone therapy, and propose the significance of further study of HCG11.

CMTM6 and PD-1/PD-L1 overexpression is associated with the clinical characteristics of malignancy in oral squamous cell carcinoma.

OBJECTIVES: This study aimed to evaluate the expression of chemokine-like factor superfamily 6 (CMTM6) and programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) in oral squamous cell carcinoma (OSCC) and to further explore its clinical significance in OSCC. STUDY DESIGN: Samples of 44 OSCC and paracancerous tissues were investigated. We estimated the expression of the 3 proteins by immunohistochemistry and further detected mRNA expression by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: Immunohistochemistry results demonstrated that the positive expression of CMTM6 and PD-1/PD-L1 in OSCC tissues was significantly higher than that in paracancerous tissues. Statistical significance was found between the 2 groups (all P < .05). Moreover, PD-L1 expression was related to OSCC clinical stage and lymph node metastasis (P < .05). The qRT-PCR results confirmed that the relative expression of CMTM6 and PD-1/PD-L1 mRNA in OSCC tissues was significantly higher than that in paracancerous tissues (all P < .05), and Spearman rank correlation showed that there was a significant relationship between mRNA and protein expression (all P < .05). CONCLUSIONS: CMTM6 and PD-1/PD-L1 were upregulated in OSCC, and CMTM6 may play a synergistic role with PD-1/PD-L1 in the immune pathway. Therefore, we believe that CMTM6 and PD-1/PD-L1 will become checkpoints for immunotherapy of OSCC.

Small nucleolar RNA host gene 8: A rising star in the targets for cancer therapy.

Long non-coding RNAs (lncRNAs) are a group of transcripts that have been considered essential participants in cancer pathogenesis and progression over the past few decades. Small nucleolar RNA host gene 8 (SNHG8) is a newly discovered lncRNA that belongs to the SNHG family, a group of transcripts that can be processed into small nucleolar RNAs and exert important biological functions. As an oncogenic factor, SNHG8 is upregulated in multiple cancer types. Herein, we summarize the biological role of SNHG8 in different cancer types and the underlying mechanisms related to the interaction between SNHG8 and microRNAs, mRNAs, and proteins. In addition, this study emphasizes the clinical value of SNHG8 in cancer, hoping to provide new insights into cancer diagnosis, prognosis, and treatment.

Central neck lymph node metastasis in oral squamous cell carcinoma at the floor of mouth.

BACKGROUND: Our goal was to analyze the incidence of level VI metastasis in previously untreated oral squamous cell carcinoma (SCC) patients and their clinicopathological and prognostic characteristics. METHODS: Oral SCC patients with level VI metastasis were retrospectively enrolled, and their demographic and pathologic features as well as their survival data were descriptively analyzed. RESULTS: A total of 13 cases from 1875 patients were included, all patients had SCC at the floor of mouth (SCCFOM). Eight (61.5%) patients had a pT4 tumor, and all patients had a pathological N3 neck with multiple positive lymph nodes. Adverse pathologic features were present in 100% of the patients. The size of the metastatic foci in level VI ranged from 2.6 cm to 4.5 cm with a mean value of 3.2 cm, and 5 patients showed a soft tissue deposit with no lymph node component. Recurrence occurred in all patients, and 11 patients died of uncontrolled cancer within 5 years after surgery. CONCLUSION: Level VI metastasis in primary oral SCCFOM is rare, and its prognosis is poor.

Bioinformatics analysis of DNMT1 expression and its role in head and neck squamous cell carcinoma prognosis.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common type of malignancy in the world. DNA cytosine-5-methyltransferase 1 (DNMT1) play key roles in carcinogenesis and regulation of the immune micro-environment, but the gene expression and the role of DNMT1 in HNSCC is unknown. In this study, we utilized online tools and databases for pan-cancer and HNSCC analysis of DNMT1 expression and its association with clinical cancer characteristics. We also identified genes that positively and negatively correlated with DNMT1 expression and identified eight hub genes based on protein-protein interaction (PPI) network analysis. Enrichment analyses were performed to explore the biological functions related with of DNMT1. The Tumor Immune Estimation Resource (TIMER) database was performed to explore the relationship between DNMT1 expression and immune-cell infiltration. We demonstrated that DNMT1 gene expression was upregulated in HNSCC and associated with poor prognosis. Based on analysis of the eight hub genes, we determined that DNMT1 may be involved in cell cycle, proliferation and metabolic related pathways. We also found that significant difference of B cells infiltration based on TP 53 mutation. These findings suggest that DNMT1 related epigenetic alterations have close relationship with HNSCC progression, and DNMT1 could be a novel diagnostic biomarker and a promising therapeutic target for HNSCC.

Gene signatures of m5C regulators may predict prognoses of patients with head and neck squamous cell carcinoma.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is the fifth most common malignancy in the world. The 5-methylcytosine (m5C) plays vital roles in pathological conditions, such as cancer. METHODS: This study investigated The Cancer Genome Atlas (TCGA) database for patients with HNSCC. We characterized the mutations and copy number variations (CNVs) in m5C-regulatory genes, in addition to analyzing their mRNA expressions. Gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) analyses were used to explore relevant functional annotations of m5C-regulatory genes. RESULTS: Alterations in m5C-regulatory genes were closely associated with patient clinicopathological characteristics. The expression of ten m5C-regulatory genes was significantly correlated with CNV patterns, indicating that m5C-regulatory genes have important regulatory effects. There was increased expression of m5C-regulatory genes, particularly ALYREF and NSUN5, during the tumor, node, and metastasis stages. Cox regression analysis revealed that the expression of DNMT1, TET2, and NSUN6 correlated with HNSCC prognoses. Furthermore, the expression of DNMT1 and ALYREF could effectively predict HNSCC risk in patients. In addition, the high expression levels of ALYREF correlated with mitochondrial function, and the elevated DNMT1 expression was associated with peptide cross-linking and humoral immunity. These results provide promising insight into the roles of m5C genes in tumor energy-metabolism and protein synthesis. CONCLUSIONS: Collectively, the results indicate that m5C plays critical roles in HNSCC progression, and is also a potential HNSCC prognostic marker.

Prediction of hepatocellular carcinoma prognosis based on expression of an immune-related gene set.

Hepatocellular carcinoma (HCC) is a common type of malignant tumor with an extremely poor prognosis. Because many HCC patients are diagnosed with advanced disease, surgical treatment is typically not possible, and other currently available treatments are often ineffective. Immunotherapy is being explored as a new treatment method for a variety of cancers, including HCC. However, there have been no systematic reports about the relationship between immune-related genes and HCC patient prognosis. In this study, we established and verified a gene set-based model to examine the relationship between immune-related genes and prognosis in HCC patients. The model was based on a dataset from The Cancer Genome Atlas (TCGA), and its stability and reliability was confirmed in four verification datasets. In addition, we performed multivariate Cox regression analyses to identify the independent risk factors affecting HCC patient prognoses. We found that this new model based on immune-related genes was effective for predicting prognosis, evaluating disease state, and identifying treatment options for HCC patients.

Temporal Proteomic Analysis of Pancreatic ß-Cells in Response to Lipotoxicity and Glucolipotoxicity.

Chronic hyperlipidemia causes the dysfunction of pancreatic ß-cells, such as apoptosis and impaired insulin secretion, which are aggravated in the presence of hyperglycemia. The underlying mechanisms, such as endoplasmic reticulum (ER) stress, oxidative stress and metabolic disorders, have been reported before; however, the time sequence of these molecular events is not fully understood. Here, using isobaric labeling-based mass spectrometry, we investigated the dynamic proteomes of INS-1 cells exposed to high palmitate in the absence and presence of high glucose. Using bioinformatics analysis of differentially expressed proteins, including the time-course expression pattern, protein-protein interaction, gene set enrichment and KEGG pathway analysis, we analyzed the dynamic features of previously reported and newly identified lipotoxicity- and glucolipotoxicity-related molecular events in more detail. Our temporal data highlight cholesterol metabolism occurring at 4 h, earlier than fatty acid metabolism that started at 8 h and likely acting as an early toxic event highly associated with ER stress induced by palmitate. Interestingly, we found that the proliferation of INS-1 cells was significantly increased at 48 h by combined treatment of palmitate and glucose. Moreover, benefit from the time-course quantitative data, we identified and validated two new molecular targets: Setd8 for cell replication and Rhob for apoptosis, demonstrating that our temporal dataset serves as a valuable resource to identify potential candidates for mechanistic studies of lipotoxicity and glucolipotoxicity in pancreatic ß-cells.

Optimizing the fragment complementation of APEX2 for detection of specific protein-protein interactions in live cells.

Dynamic protein-protein interactions (PPIs) play crucial roles in cell physiological processes. The protein-fragment complementation (PFC) assay has been developed as a powerful approach for the detection of PPIs, but its potential for identifying protein interacting regions is not optimized. Recently, an ascorbate peroxidase (APEX2)-based proximity-tagging method combined with mass spectrometry was developed to identify potential protein interactions in live cells. In this study, we tested whether APEX2 could be employed for PFC. By screening split APEX2 pairs attached to FK506-binding protein 12 (FKBP) and the FKBP12-rapamycin binding (FRB) domain, which interact with each other only in the presence of rapamycin, we successfully obtained an optimized pair for visualizing the interaction between FRB and FKBP12 with high specificity and sensitivity in live cells. The robustness of this APEX2 pair was confirmed by its application toward detecting the STIM1 and Orial1 homodimers in HEK-293 cells. With a subsequent mass spectrometry analysis, we obtained five different biotinylated sites that were localized to the known interaction region on STIM1 and were only detected when the homodimer formed. These results suggest that our PFC pair of APEX2 provides a potential tool for detecting PPIs and identifying binding regions with high specificity in live cells.