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Enzymes have evolved to catalyze their precise reactions at the necessary rates, locations, and time to facilitate our development, to respond to a variety of insults and challenges, and to maintain a healthy, balanced state. Enzymes achieve this extraordinary feat through their unique kinetic parameters, myriad regulatory strategies, and their sensitivity to their surroundings, including substrate concentration and pH. The Cancer Genome Atlas (TCGA) highlights the extraordinary number of ways in which the finely tuned activities of enzymes can be disrupted, contributing to cancer development and progression often due to somatic and/or inherited genetic alterations. Rather than being limited to the domain of enzymologists, kinetic constants such as kcat, Km, and kcat/Km are highly informative parameters that can impact a cancer patient in tangible ways—these parameters can be used to sort tumor driver mutations from passenger mutations, to establish the pathways that cancer cells rely on to drive patients’ tumors, to evaluate the selectivity and efficacy of anti-cancer drugs, to identify mechanisms of resistance to treatment, and more. In this review, we will discuss how changes in enzyme activity, primarily through somatic mutation, can lead to altered kinetic parameters, new activities, or changes in conformation and oligomerization. We will also address how changes in the tumor microenvironment can affect enzymatic activity, and briefly describe how enzymology, when combined with additional powerful tools, and can provide us with tremendous insight into the chemical and molecular mechanisms of cancer.

BACKGROUND Green synthesis of silver nanoparticles (AgNPs) has become widely practiced worldwide. In this study, AgNPs were synthesized using a hot-water extract of the edible mushroom, Pleurotus sajor-caju. The product, PSC-AgNPs, was characterized by using UV-Vis spectra, DLS analysis, TEM, XRD and FTIR spectrometry. To assess its antifungal activity against C. albicans, gene transcription and protein expression analyses were conducted for CaICL1 and its product, ICL using RT-qPCR and western blot, respectively. RESULTS PSC-AgNPs with an average particle size of 11.68 nm inhibited the growth of the pathogenic yeast C. albicans. MIC and MFC values were 250 mg/L and 500 mg/L, respectively. TEM images revealed that the average particle size of PSC-AgNPs was 16.8 nm, with the values for zeta potential and the polydispersity index being -8.54 mV and 0.137, respectively. XRD and FTIR spectra showed PSC-AgNPs to have a face-centered cubic (FCC) crystalline structure. The polysaccharides and amino acid residues present in P. sajor-caju extract were found to be involved in reducing Ag+ to AgNP. Both CaICL1 transcription and ICL protein expression were found to be suppressed in the cells treated with PSC-AgNPs as compared with the control. CONCLUSION Our PSC-AgNPs preparation makes for a promising antifungal agent that can downregulate isocitrate lyase.

Despite the availability of anticancer drugs, breast cancer remains the most death-causing tumor-related disease in women. Hence, there is a need for discovery and development of efficient alternative drugs, and sources such as plants need to be explored. In this study, antioxidant capacities and inhibitory effects against MCF7 cells of the extracts of stem bark of three Nigerian medicinal plants (Detarium microcarpum, Guiera senegalensis, and Cassia siamea) were investigated. The D. microcarpum extracts had the highest antioxidant and antiproliferative effects, followed by that of G. senegalensis, and the C. siamea extracts had minimal effects. The IC50 values of the methanol and aqueous extracts from the three plants that inhibited the proliferation of MCF7 cells ranged from 78–> 500 μg/ml. Moreover, all the plant extracts but the aqueous extract of Cassia siamea exhibited antimetastatic action and induced apoptosis and cell cycle arrest in MCF7 cells. Liquid chromatography/time-of-flight/mass spectrometry profiling revealed that the five potent extracts contain many phenols and omega-6 fatty acids, and some of the identified compounds (isorhamnetin, eupatorin, alpinumisoflavone, procyanidin B3, syringin, and gallic acid) have been reported to have antiproliferative effects on cancer cells. Hence, the stem bark of these plants could be potential sources of antibreast cancer agents.

Despite the availability of anticancer drugs, breast cancer remains the most death-causing tumor-related disease in women. Hence, there is a need for discovery and development of efficient alternative drugs, and sources such as plants need to be explored. In this study, antioxidant capacities and inhibitory effects against MCF7 cells of the extracts of stem bark of three Nigerian medicinal plants (Detarium microcarpum, Guiera senegalensis, and Cassia siamea) were investigated. The D. microcarpum extracts had the highest antioxidant and antiproliferative effects, followed by that of G. senegalensis, and the C. siamea extracts had minimal effects. The IC50 values of the methanol and aqueous extracts from the three plants that inhibited the proliferation of MCF7 cells ranged from 78–> 500 μg/ml. Moreover, all the plant extracts but the aqueous extract of Cassia siamea exhibited antimetastatic action and induced apoptosis and cell cycle arrest in MCF7 cells. Liquid chromatography/time-of-flight/mass spectrometry profiling revealed that the five potent extracts contain many phenols and omega-6 fatty acids, and some of the identified compounds (isorhamnetin, eupatorin, alpinumisoflavone, procyanidin B3, syringin, and gallic acid) have been reported to have antiproliferative effects on cancer cells. Hence, the stem bark of these plants could be potential sources of antibreast cancer agents.

Background A norovirus maintains its viability, infectivity and virulence by its ability to replicate. However, the biological mechanisms of the process remain to be explored. In this work, the NanoLuc™ Luciferase gene was used to develop a reporter-tagged replicon system to study norovirus replication. Methods The NanoLuc™ Luciferase reporter protein was engineered to be expressed as a fusion protein for MNV-1 minor capsid protein, VP2. The foot-and-mouth disease virus 2A (FMDV2A) sequence was inserted between the 3'end of the reporter gene and the VP2 start sequence to allow co-translational 'cleavage' of fusion proteins during intracellular transcript expression. Amplification of the fusion gene was performed using a series of standard and overlapping polymerase chain reactions. The resulting amplicon was then cloned into three readily available backbones of MNV-1 cDNA clones. Results Restriction enzyme analysis indicated that the NanoLucTM Luciferase gene was successfully inserted into the parental MNV-1 cDNA clone. The insertion was further confirmed by using DNA sequencing. Conclusion NanoLuc™ Luciferase-tagged MNV-1 cDNA clones were successfully engineered. Such clones can be exploited to develop robust experimental assays for in vitro assessments of viral RNA replication.

Green synthesis of silver nanoparticles (AgNPs) has become widely practiced worldwide. In this study, AgNPs were synthesized using a hot-water extract of the edible mushroom Pleurotus sajor-caju. The product, PSC-AgNPs, was characterized by using UV-visible spectra, dynamic light scattering analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectrometry. To assess its antifungal activity against Candida albicans, gene transcription and protein expression analyses were conducted for CaICL1 and its product, ICL, using real-time quantitative polymerase chain reaction and western blot, respectively.PSC-AgNPs with an average particle size of 11.68 nm inhibited the growth of the pathogenic yeast C. albicans. Values for minimum inhibitory concentration and minimum fungicidal concentration were 250 and 500 mg LOur PSC-AgNP preparation makes for a promising antifungal agent that can downregulate isocitrate lyase. © 2017 Society of Chemical Industry.

Background A major characteristic of Candida biofilm cells that differentiates them from free-floating cells is their high tolerance to antifungal drugs. This high resistance is attributed to particular biofilm properties, including the accumulation of extrapolymeric substances, morphogenetic switching, and metabolic flexibility. Objectives This study evaluated the roles of metabolic processes (in particular the glyoxylate cycle) on biofilm formation, antifungal drug resistance, morphology, and cell wall components. Methods Growth, adhesion, biofilm formation, and cell wall carbohydrate composition were quantified for isogenic Candida albicans ICL1/ICL1, ICL1/icl1, and icl1/icl1 strains. The morphology and topography of these strains were compared by light microscopy and scanning electron microscopy. FKS1 (glucan synthase), ERG11 (14-α-demethylase), and CDR2 (efflux pump) mRNA levels were quantified using qRT-PCR. Results The ICL1/icl1 and icl1/icl1 strains formed similar biofilms and exhibited analogous drug-tolerance levels to the control ICL1/ICL1 strains. Furthermore, the drug sequestration ability of β-1, 3-glucan, a major carbohydrate component of the extracellular matrix, was not impaired. However, the inactivation of ICL1 did impair morphogenesis. ICL1 deletion also had a considerable effect on the expression of the FKS1, ERG11, and CDR2 genes. FKS1 and ERG11 were upregulated in ICL1/icl1 and icl1/icl1 cells throughout the biofilm developmental stages, and CDR2 was upregulated at the early phase. However, their expression was downregulated compared to the control ICL1/ICL1 strain. Conclusions We conclude that the glyoxylate cycle is not a specific determinant of biofilm drug resistance.

The chemical nature of most of the mycotoxins makes them highly liposoluble compounds that can be absorbed from the site of exposure such as from the gastrointestinal and respiratory tract to the blood stream where it can be dissimilated throughout the body and reach different organs such as the liver and kidneys. Mycotoxins have a strong tendency and ability to penetrate the human and animal cells and reach the cellular genome where it causes a major mutagenic change in the nucleotide sequence which leads to strong and permanent defects in the genome. This defect will eventually be transcribed, translated and lead to the development of cancer. In this review, the chemical and physical nature of mycotoxins, the action of mycotoxins on the cellular genome and its effect on humans, mycotoxins and their carcinogenicity and mycotoxins research gaps are discussed, and new research areas are suggested. The research review posed various questions. What are the different mycotoxins that can cause cancer, what is the role of mycotoxins in causing cancer and what types of cancers can be caused by mycotoxins? These questions have been selected due to the significant increase in the mycotoxin contamination and the cancer incidence rate in the contemporary world. By revealing and understanding the role of mycotoxins in developing cancer, measures to reduce the risks and incidents of cancer could be taken.

The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans.

Aquilaria crassna (agarwood) has been used in traditional Asian medicine to treat vomiting, rheumatism, asthma, cough and inflammation. Despite the wide range of ethno-pharmacological use of agarwood, its anti-angiogenic effect has not previously been evaluated through systematic studies. Therefore, the aim of this study was to prepare essential oils extracts from the stem bark of A. crassna native to Malaysia, and determine their anti-proliferative and anti-angiogenic activities. Stem bark samples were extracted with 80% ethanol and hydrodistillation methods. The resulting essential oils from both extraction approaches were subjected for cytotoxic activity using four cancer cell lines and one normal cell line. Hydrodistilled essential oils displayed significant cytotoxic effect against HCT 116 cells with the lowest IC50 value calculated (28.0 ± 1.5 μg/mL). Furthermore, we have investigated the effect of hydrodistilled essential oils (active extract) on angiogenesis in vitro and ex vivo, and found that essential oils directly inhibited tube formation after plating endothelial cells on matrigel. In addition, essential oils caused significant inhibition of microvessels outgrowth of rat aortic ring assay in a dose-dependent manner (P

Mutations in isocitrate dehydrogenase 1 (IDH1) impart a neomorphic reaction that produces the oncometabolite D-2-hydroxyglutarate (D2HG), which can inhibit DNA and histone demethylases to drive tumorigenesis via epigenetic changes. Though heterozygous point mutations in patients primarily affect residue R132, there are myriad D2HG-producing mutants that display unique catalytic efficiency of D2HG production. Here, we show that catalytic efficiency of D2HG production is greater in IDH1 R132Q than R132H mutants, and expression of IDH1 R132Q in cellular and mouse xenograft models leads to higher D2HG concentrations in cells, tumors, and sera compared to R132H-expressing models. Reduced representation bisulfite sequencing (RRBS) analysis of xenograft tumors shows expression of IDH1 R132Q relative to R132H leads to hypermethylation patterns in pathways associated with DNA damage. Transcriptome analysis indicates that the IDH1 R132Q mutation has a more aggressive pro-tumor phenotype, with members of EGFR, Wnt, and PI3K signaling pathways differentially expressed, perhaps through non-epigenetic routes. Together, these data suggest that the catalytic efficiency of IDH1 mutants modulate D2HG levels in cellular and in vivo models, resulting in unique epigenetic and transcriptomic consequences where higher D2HG levels appear to be associated with more aggressive tumors.