An alternative molecular mechanism of action of 5-fluorouracil, a potent anticancer drug

Finding a Direct Method for a Dynamic Process: The DD (Direct and Dynamic) Cell-Tox Method

The main focus of in vitro toxicity assessment methods is to assess the viability of the cells, which is usually based on metabolism changes. Yet, when exposed to toxic substances, the cell triggers multiple signals in response. With this in mind, we have developed a promising cell-based toxicity method that observes various cell responses when exposed to toxic substances (either death, division, or remain viable). Based on the collective cell response, we observed and predicted the dynamics of the cell population to determine the toxicity of the toxicant. The method was tested with two different conformations: In the first conformation, we exposed a monoculture model of blood macrophages to UV light, hydrogen peroxide, nutrient deprivation, tetrabromobisphenol A, fatty acids, and 5-fluorouracil. In the second, we exposed a coculture liver model consisting of hepatocytes, hepatic stellate cells, Kupffer cells, and liver sinusoidal endothelial cells to rifampicin, ibuprofen, and 5-fluorouracil. The method showed good accuracy compared to established toxicity assessment methods. In addition, this approach provided more representative information on the toxic effects of the compounds, as it considers the different cellular responses induced by toxic agents.

Development of 5-Fluorouracil/pH-Responsive Adjuvant-Embedded Extracellular Vesicles for Targeting αvβ3 Integrin Receptors in Tumors

To selectively target and treat murine melanoma B16BL6 tumors expressing αvβ3 integrin receptors, we engineered tumor-specific functional extracellular vesicles (EVs) tailored for the targeted delivery of antitumor drugs. This objective was achieved through the incorporation of a pH-responsive adjuvant, cyclic arginine-glycine-aspartic acid peptide (cRGD, serving as a tumor-targeting ligand), and 5-fluorouracil (5-FU, employed as a model antitumor drug). The pH-responsive adjuvant, essential for modulating drug release, was synthesized by chemically conjugating 3-(diethylamino)propylamine (DEAP) to deoxycholic acid (DOCA, a lipophilic substance capable of integrating into EVs' membranes), denoted as DEAP-DOCA. The DOCA, preactivated using N-(2-aminoethyl)maleimide (AEM), was chemically coupled with the thiol group of the cRGD-DOCA through the thiol-maleimide click reaction, resulting in the formation of cRGD-DOCA. Subsequently, DEAP-DOCA, cRGD-DOCA, and 5-FU were efficiently incorporated into EVs using a sonication method. The resulting tumor-targeting EVs, expressing cRGD ligands, demonstrated enhanced in vitro/in vivo cellular uptake specifically for B16BL6 tumors expressing αvβ3 integrin receptors. The ionization characteristics of the DEAP in DEAP-DOCA induced destabilization of the EVs membrane at pH 6.5 through protonation of the DEAP substance, thereby expediting 5-FU release. Consequently, an improvement in the in vivo antitumor efficacy was observed for B16BL6 tumors. Based on these comprehensive in vitro/in vivo findings, we anticipate that this EV system holds substantial promise as an exceptionally effective platform for antitumor therapeutic delivery.

Can Some Anticancer Drugs Be Repurposed to Treat Amyotrophic Lateral Sclerosis? A Brief Narrative Review

Amyotrophic lateral sclerosis (ALS) is a rare progressive motor neuron disease that, due to its high complexity, still lacks effective treatments. Development of a new drug is a highly costly and time-consuming process, and the repositioning of approved drugs can represent an efficient strategy to provide therapeutic opportunities. This is particularly true for rare diseases, which are characterised by small patient populations and therefore attract little commercial interest. Based on the overlap between the biological background of cancer and neurodegeneration, the repurposing of antineoplastic drugs for ALS has been suggested. The objective of this narrative review was to summarise the current experimental evidence on the use of approved anticancer drugs in ALS. Specifically, anticancer drugs belonging to different classes were found to act on mechanisms involved in the ALS pathogenesis, and some of them proved to exert beneficial effects in ALS models. However, additional studies are necessary to confirm the real therapeutic potential of anticancer drugs for repositioning in ALS treatment.

Intralesional 5-fluorouracil as a management for cutaneous squamous cell carcinomas: A rural Australian retrospective case series

While the gold standard treatment for cutaneous squamous cell carcinomas (cSCCs) is surgical removal, there is a risk of infection, cosmetic and functional deficits. Intralesional 5-fluorouracil (5-FU) has been shown to be a potential non-surgical treatment modality for cSCCs in the literature. The aim was to investigate the safety and feasibility of using intralesional 5-FU to treat cSCCs. A literature review was conducted and a retrospective case series analysed patients who commenced intralesional 5-FU treatment for at least one cSCC between 1 January 2018 and 1 January 2019 at a private clinic in Orange, Australia. Inclusion criteria include: at least one cSCC was treated; only intralesional 5-FU was used; and treatment was ceased due to complete or inadequate remission, or adverse effects. There were 15 patients (7 female, 8 male, 60-99 years) and 20 out 21 cSCC lesions (82.6%) cleared while one lesion (4.3%) recurred. Six lesions (26.1%) ulcerated, four lesions became infected (17.4%) and one patient had an allergic reaction. The average number of treatments required for clearance was four (range 1-35), and the average 5-FU dose used was 75 mg (range 50-150 mg). Across 25 studies, 656 out of 708 lesions cleared (92.66%). Adverse effects were self-limiting and mostly well-tolerated. Intralesional 5-FU is an affordable and non-invasive non-surgical treatment modality that appears feasible to use for cSCCs and has a relatively low treatment-associated morbidity. Future clinical trials can help develop a protocol to guide clinicians in its use.

Downregulation of KRAB zinc finger proteins in 5-fluorouracil resistant colorectal cancer cells

Radio-chemotherapy with 5-flu orouracil (5-FU) is the standard of care treatment for patients with colorectal cancer, but it is only effective for a third of them. Despite our understanding of the mechanism of action of 5-FU, drug resistance remains a significant limitation to the clinical use of 5-FU, as both intrinsic and acquired chemoresistance represents the major obstacles for the success of 5-FU-based chemotherapy. In order to identify the mechanism of acquired resistance, 5-FU chemoresistance was induced in CRC cell lines by passaging cells with increasing concentrations of 5-FU. To study global molecular changes, quantitative proteomics and transcriptomics analyses were performed on these cell lines, comparing the resistant cells as well as the effect of chemo and radiotherapy. Interestingly, a very high proportion of downregulated genes were annotated as transcription factors coding for Krüppel-associated box (KRAB) domain-containing zinc-finger proteins (KZFPs), the largest family of transcriptional repressors. Among nearly 350 KRAB-ZFPs, almost a quarter were downregulated after the induction of a 5-FU-resistance including a common one between the three CRC cell lines, ZNF649, whose role is still unknown. To confirm the observations of the proteomic and transcriptomic approaches, the abundance of 20 different KZFPs and control mRNAs was validated by RT-qPCR. In fact, several KZFPs were no longer detectable using qPCR in cell lines resistant to 5-FU, and the KZFPs that were downregulated only in one or two cell lines showed similar pattern of expression as measured by the omics approaches. This proteomic, transcriptomic and genomic analysis of intrinsic and acquired resistance highlights a possible new mechanism involved in the cellular adaptation to 5-FU and therefore identifies potential new therapeutic targets to overcome this resistance.

Hepatoprotective Activity of Gentisic Acid on 5-Fluorouracil-induced Hepatotoxicity in Wistar Rats

Objectives

5-Fluorouracil (5-FU) is a very potent and effective antineoplastic drug that has been widely used for the management of various types of cancer. However, the clinical use of 5-FU is often associated with severe toxicities including hepatotoxicity, which limit its therapeutic use as a potent anticancer agent. The present study aimed to evaluate the hepatoprotective activity of a plant phenolic acid, gentisic acid (GA) (2,5-dihyroxybenzoic acid), against hepatotoxicity induced by 5-FU administration in Wistar rats.

Materials and Methods

The rats were randomly divided into six groups, with six rats per group. Among these, group I and II served as normal control and 5-FU control groups, respectively. The rats in these groups received distilled water (1 mL/kg) for 14 days by oral route. Groups III, IV, V, and VI served as test groups and received GA at doses of 3, 10, 30, and 100 mg/kg body weight, respectively, via oral route for 14 days. From Day 9 onwards, all the groups, except group I, received intraperitoneal dose of 5-FU (20 mg/kg body weight) for five days up to day 14. At the end of the study, the rats were sacrificed, blood was withdrawn for biochemical estimations, and hepatic tissues were excised for histopathological evaluations.

Results

Administration of 5-FU at a dose of 20 mg/kg body weight resulted in a significant increase in the serum levels of hepatic biomarkers, including aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, direct bilirubin, and total bilirubin. In comparison to these, 5-FU treatment resulted in a reduction in total protein content (TPC). This was accompanied by significant histopathological changes in the hepatic tissues of the rats, indicating severe hepatotoxicity. Pre- and co-administration of GA with 5-FU at doses of 30 and 100 mg/kg body weight for 14 days resulted in a dose-dependent amelioration of the 5-FU induced alterations in the biochemical and histopathological parameters.

Conclusion

The results of the study highlighted the potential of GA as a hepatoprotective agent for the prevention of 5-FU-induced hepatotoxicity.

Transforming early pharmaceutical assessment of genotoxicity: applying statistical learning to a high throughput, multi end point in vitro micronucleus assay

To provide a comprehensive analysis of small molecule genotoxic potential we have developed and validated an automated, high-content, high throughput, image-based in vitro Micronucleus (IVM) assay. This assay simultaneously assesses micronuclei and multiple additional cellular markers associated with genotoxicity. Acoustic dosing (≤ 2 mg) of compound is followed by a 24-h treatment and a 24-h recovery period. Confocal images are captured [Cell Voyager CV7000 (Yokogawa, Japan)] and analysed using Columbus software (PerkinElmer). As standard the assay detects micronuclei (MN), cytotoxicity and cell-cycle profiles from Hoechst phenotypes. Mode of action information is primarily determined by kinetochore labelling in MN (aneugencity) and γH2AX foci analysis (a marker of DNA damage). Applying computational approaches and implementing machine learning models alongside Bayesian classifiers allows the identification of, with 95% accuracy, the aneugenic, clastogenic and negative compounds within the data set (Matthews correlation coefficient: 0.9), reducing analysis time by 80% whilst concurrently minimising human bias. Combining high throughput screening, multiparametric image analysis and machine learning approaches has provided the opportunity to revolutionise early Genetic Toxicology assessment within AstraZeneca. By multiplexing assay endpoints and minimising data generation and analysis time this assay enables complex genotoxicity safety assessments to be made sooner aiding the development of safer drug candidates.

Nano-scale imaging of dual stable isotope labeled oxaliplatin in human colon cancer cells reveals the nucleolus as a putative node for therapeutic effect

Oxaliplatin shows a superior clinical activity in colorectal cancer compared to cisplatin. Nevertheless, the knowledge about its cellular distribution and the mechanisms responsible for the different range of oxaliplatin-responsive tumors is far from complete. In this study, we combined highly sensitive element specific and isotope selective imaging by nanometer-scale secondary ion mass spectrometry (NanoSIMS) with transmission electron microscopy to investigate the subcellular accumulation of oxaliplatin in three human colon cancer cell lines (SW480, HCT116 wt, HCT116 OxR). Oxaliplatin bearing dual stable isotope labeled moieties, i.e. ²H-labeled diaminocyclohexane (DACH) and ¹³C-labeled oxalate, were applied for comparative analysis of the subcellular distribution patterns of the central metal and the ligands. In all the investigated cell lines, oxaliplatin was found to have a pronounced tendency for cytoplasmic aggregation in single membrane bound organelles, presumably related to various stages of the endocytic pathway. Moreover, nuclear structures, heterochromatin and in particular nucleoli, were affected by platinum-drug exposure. In order to explore the consequences of oxaliplatin resistance, subcellular drug distribution patterns were investigated in a pair of isogenic malignant cell lines with distinct levels of drug sensitivity (HCT116 wt and HCT116 OxR, the latter with acquired resistance to oxaliplatin). The subcellular platinum distribution was found to be similar in both cell lines, with only slightly higher accumulation in the sensitive HCT116 wt cells which is inconsistent with the resistance factor of more than 20-fold. Instead, the isotopic analysis revealed a disproportionally high accumulation of the oxalate ligand in the resistant cell line.

Design, synthesis, biological evaluation and molecular docking of new 1,3,4-oxadiazole homonucleosides and their double-headed analogs as antitumor agents

A novel series of homonucleosides and their double-headed analogs containing theophylline, 1,3,4-oxadiazole, and variant nucleobases was designed and synthesized. The new derivatives were fully characterized by HRMS, FT-IR, ¹H NMR, and ¹³C NMR. The cytotoxic activities of all prepared compounds were screened in vitro against four cell lines, including fibrosarcoma (HT-1080), breast (MCF-7 and MDA-MB-231), and lung carcinoma (A-549). The double-headed analogue 18 showed marked growth inhibition against all the cell lines tested, specifically in HT-1080, with an IC₅₀ values of 17.08 ± 0.97 µM. The possible mechanism of apoptosis was investigated using Annexin V staining, caspase-3/7 activity, and analysis cell cycle progression. The compound 18 induced apoptosis through caspase-3/7 activation and cell-cycle arrest in HT-1080 and A-549 cells. The molecular docking confirms that the compound 18 activated caspase-3 via the formation of hydrogen bonds and hydrophobic interactions.

Quantitative analysis of hydrogen and chalcogen bonds in two pyrimidine-5-carbonitrile derivatives, potential DHFR inhibitors: an integrated crystallographic and theoretical study

Two potential bioactive pyrimidine-5-carbonitrile derivatives have been synthesized and characterized by spectroscopic techniques (1H and 13C-NMR) and the three dimensional structures were elucidated by single crystal X-ray diffraction at low temperature (160 K). In both structures, the molecular conformation is locked by an intramolecular C-H⋯C interaction involving the cyano and CH of the thiophene and phenyl rings. The intermolecular interactions were analyzed in a qualitative manner based on the Hirshfeld surface and 2D-fingerprint plots. The results suggest that the phenyl and thiophene moieties have an effect on the crystal packing. For instance, the chalcogen bonds are only preferred in the thiophene derivative. However, both structures uses a common N-H⋯O hydrogen bond motif. Moreover, the structures of 1 and 2 display 1D isostructurality and molecular chains stabilize by intermolecular N-H⋯O and N-H⋯N hydrogen bonds. The nature and extent of different non-covalent interactions were further characterized by the topological parameters derived from the quantum theory of atoms-in-molecules approach. This analysis indicates that apart from N-H⋯O hydrogen bonds, other non-covalent interactions are closed-shell in nature. A strong and linear N-H⋯O hydrogen bond shows intermediate bonding character between shared and closed-shell interactions. The molecular docking analysis suggests that both compounds display potential inhibitory effect against the dihydrofolate reductase (DHFR) enzyme from humans and Staphylococcus aureus.

Residues within the Foot-and-Mouth Disease Virus 3Dpol Nuclear Localization Signal Affect Polymerase Fidelity

Many RNA viruses encode a proof-reading deficient, low-fidelity RNA-dependent polymerase (RdRp), which generates genetically diverse populations that can adapt to changing environments and thwart antiviral therapies. 3D^pol, the RdRp of the foot-and-mouth disease virus (FMDV), is responsible for replication of viral genomes. The 3D^pol N terminus encodes a nuclear localization signal (NLS) sequence,MRKTKLAPT, important for import of the protein to host nucleus. Previous studies showed that substitutions at residues 18 and 20 of the NLS are defective in proper incorporation of nucleotides and RNA binding. Here, we use a systematic alanine scanning mutagenesis approach to understand the role of individual residues of the NLS in nuclear localization and nucleotide incorporation activities of 3D^pol We identify two residues of 3D^pol NLS, T19 and L21, that are important for the maintenance of enzyme fidelity. The 3D^pol NLS alanine substitutions of T19 and L21 results in aberrant incorporation of nucleoside analogs, conferring a low fidelity phenotype of the enzyme. A molecular dynamics simulation of RNA- and mutagen (RTP)-bound 3D^pol revealed that the T19 residue participates in a hydrogen bond network, including D165 in motif F and R416 at the C terminus of the FMDV 3D^pol and RNA template-primer. Based on these findings and previous studies, we conclude that at least the first six residues of theMRKTKLAPT sequence motif play a vital role in the maintenance of faithful RNA synthesis activity (fidelity) of FMDV 3D^pol, suggesting that the role of the NLS motif in similar viral polymerases needs to be revisited.IMPORTANCE In this study, we employed genetic and molecular dynamics approaches to analyze the role of individual amino acids of the FMDV 3D^pol nuclear localization signal (NLS). The NLS residues were mutated to alanine using a type A full-genome cDNA clone, and the virus progeny was analyzed for defects in growth and in competition with the parental virus. We identified two mutants in 3D^pol, T19A and L21A, that exhibited high rate of mutation, were sensitive to nucleotide analogs, and displayed reduced replicative fitness compared to the parental virus. Using molecular dynamics simulation, we demonstrated that residues T19 and L21 played a role in the structural configuration of the interaction network at the 3D^pol palm subdomain. Cumulatively, our data suggest that the T19 and L21 3D^pol amino acids are important for maintaining the fidelity of the FMDV polymerase and ensuring faithful replication of the FMDV genome.

Targeting Protein Synthesis in Colorectal Cancer

Under physiological conditions, protein synthesis controls cell growth and survival and is strictly regulated. Deregulation of protein synthesis is a frequent event in cancer. The majority of mutations found in colorectal cancer (CRC), including alterations in the WNT pathway as well as activation of RAS/MAPK and PI3K/AKT and, subsequently, mTOR signaling, lead to deregulation of the translational machinery. Besides mutations in upstream signaling pathways, deregulation of global protein synthesis occurs through additional mechanisms including altered expression or activity of initiation and elongation factors (e.g., eIF4F, eIF2α/eIF2B, eEF2) as well as upregulation of components involved in ribosome biogenesis and factors that control the adaptation of translation in response to stress (e.g., GCN2). Therefore, influencing mechanisms that control mRNA translation may open a therapeutic window for CRC. Over the last decade, several potential therapeutic strategies targeting these alterations have been investigated and have shown promising results in cell lines, intestinal organoids, and mouse models. Despite these encouraging in vitro results, patients have not clinically benefited from those advances so far. In this review, we outline the mechanisms that lead to deregulated mRNA translation in CRC and highlight recent progress that has been made in developing therapeutic strategies that target these mechanisms for tumor therapy.

Inhibiting eukaryotic ribosome biogenesis

BACKGROUND

Ribosome biogenesis is a central process in every growing cell. In eukaryotes, it requires more than 250 non-ribosomal assembly factors, most of which are essential. Despite this large repertoire of potential targets, only very few chemical inhibitors of ribosome biogenesis are known so far. Such inhibitors are valuable tools to study this highly dynamic process and elucidate mechanistic details of individual maturation steps. Moreover, ribosome biogenesis is of particular importance for fast proliferating cells, suggesting its inhibition could be a valid strategy for treatment of tumors or infections.

RESULTS

We systematically screened ~ 1000 substances for inhibitory effects on ribosome biogenesis using a microscopy-based screen scoring ribosomal subunit export defects. We identified 128 compounds inhibiting maturation of either the small or the large ribosomal subunit or both. Northern blot analysis demonstrates that these inhibitors cause a broad spectrum of different rRNA processing defects.

CONCLUSIONS

Our findings show that the individual inhibitors affect a wide range of different maturation steps within the ribosome biogenesis pathway. Our results provide for the first time a comprehensive set of inhibitors to study ribosome biogenesis by chemical inhibition of individual maturation steps and establish the process as promising druggable pathway for chemical intervention.

Synergistic effect of kaempferol and 5‑fluorouracil on the growth of colorectal cancer cells by regulating the PI3K/Akt signaling pathway

Combination chemotherapy with chemosensitizers can exert synergistic therapeutic effects, reduce toxicity, and delay the induction of drug resistance. In the present study, the antitumor effects were investigated, and the possible underlying mechanisms of kaempferol combined with 5‑fluorouracil (5‑FU) in colorectal cancer cells were explored. HCT‑8 or HCT‑116 cells were treated with various concentrations of kaempferol and/or 5‑FU for the indicated time‑points. An MTT assay was used to determine cell viability, whereas the synergistic effects were assessed by calculating the combination indices of kaempferol and 5‑FU. Annexin V analysis and Hoechst staining were used to determine cell apoptosis. q‑PCR and western blotting were performed to determine the expression levels of Bax, Bcl‑2, thymidylate synthase (TS), PTEN, PI3K, AKT, and p‑AKT. The combination of kaempferol and 5‑FU was determined to be more effective in inhibiting cell viability than either of the agents alone. The inhibition of tumors in response to kaempferol and 5‑FU was associated with the reduction in proliferation ability and stimulation of apoptosis. The protein results indicated that kaempferol and 5‑FU could significantly upregulate the expression levels of Bax and downregulate the expression levels of Bcl‑2 and TS. Furthermore, the combination treatment greatly inhibited the activation of the PI3K/Akt pathway, suggesting the involvement of this pathway in the synergistic effects. The present study demonstrated that kaempferol has a synergistic effect with 5‑FU by inhibiting cell proliferation and inducing apoptosis in colorectal cancer cells via suppression of TS or attenuation of p‑Akt activation. The combination of kaempferol and 5‑FU may be used as an effective therapeutic strategy for colorectal cancer.

Chemotherapeutic agent 5-fluorouracil increases survival of SOD1 mouse model of ALS

Amyotrophic lateral sclerosis (ALS) is a lethal motor neuron disease with no cure. Currently there are only two ALS drugs approved by the FDA, both with a limited therapeutic effect. In the search for drug candidates for ALS, we studied the effect of known stem cell mobilizing agents (treatment) and antimetabolite 5-fluorouracil (5-FU) (anti-treatment) in SOD1G93A model of ALS. Surprisingly, we found that anti-cancer drug 5-FU increases lifespan, delays the disease onset and improves motor performance in ALS mice. Although we were not able to demonstrate the mechanistic basis of the beneficial 5-FU action in ALS mice, our findings suggest that 5-FU or similar drugs are possible drug candidates for the treatment of motor neuron diseases through drug repurposing.

Therapeutic use of fluorinated nucleosides – progress in patents

Fluorinated nucleosides constitute a large class of chemotherapeutics approved for clinical use. The pharmacokinetic and pharmacodynamic properties of a drug can be affected, as a consequence of modulation of electronic, lipophilic and steric parameters, by the introduction of fluorine into the structure of drug-like molecule. Herein, we focus on fluorinated-nucleoside analogs, their therapeutic use and applications based on the patent literature from 2014 to 2018. We briefly discuss the clinical properties of anticancer and antiviral fluorine-containing nucleos(t)ides US FDA-approved or in development, and highlight their resistance mechanisms and limitations in the clinic. We emphasize patent inventions related to improved synthetic methods toward selected nucleos(t)ide analogs including the phosphoramidate sofosbuvir and 18F-labeled nucleosides FLT and FMAU, used as a 18F-PET tracers.

Experimental (FT-IR, Laser-Raman and NMR) and theoretical comparative study on 2-benzylsulfanyl-4-pentyl-6-(phenylsulfanyl)pyrimidine-5-carbonitrile, a potential bioactive agent

In this paper, the experimental and theoretical vibrational frequencies of a potential bioactive pyrimidine derivative molecule named 2-benzylsulfanyl-4-pentyl-6-(phenylsulfanyl)pyrimidine-5-carbonitrile has been investigated. The experimental FT-IR and Laser-Raman spectra of the studied molecule are in the region (4000–400[Formula: see text]cm[Formula: see text] and (4000–100[Formula: see text]cm[Formula: see text], respectively, in gas phase. The vibrational modes and optimized ideal structure parameters(bond lengths, bond angles and selected dihedral angles) were calculated by using DFT/B3LYP, DFT/BHandHLYP and DFT/PBE1PBE methods with 6-311[Formula: see text]G(d,p) basis set. The theoretical mode assignments have been obtained by using potential energy distribution (PED) with the VEDA4 software program. Additionally, infrared and Raman intensities, the highest occupied molecular orbital (HOMO), the lowest unoccupied molecular orbital (LUMO) energies and their clouds, and other related molecular properties were calculated and evaluated. The proton (1H) and carbon-13 ([Formula: see text]C) nuclear magnetic resonance (NMR) chemical shifts have been investigated for the title molecule, both experimentally (in DMSO-d[Formula: see text] and theoretically (in vacuum and DMSO). The thermodynamic properties of the tile compound have been investigated using the mentioned theoretical computational methods. The results revealed that there isgood agreement between experimental and theoretical results and these results have supported the related literature.

Triamcinolone acetonide intralesional injection for the treatment of keloid scars: patient selection and perspectives

Keloids are pathological scars presenting as nodular lesions that extend beyond the area of injury. They do not spontaneously regress, often continuing to grow over time. The abnormal wound-healing process underlying keloid formation results from the lack of control mechanisms self-regulating cell proliferation and tissue repair. Keloids may lead to cosmetic disfigurement and functional impairment and affect the quality of life. Although several treatments were reported in the literature, no universally effective therapy was found to date. The most common approach is intralesional corticosteroid injection alone or in combination with other treatment modalities. Triamcinolone acetonide (TAC) is the most commonly used intralesional corticosteroid. The aim of this article was to review the use of TAC, alone or in combination, in the treatment of keloid scars. The response to corticosteroid injection alone is variable with 50-100% regression and a recurrence rate of 33% and 50% after 1 and 5 years, respectively. Compared to verapamil, TAC showed a faster and more effective response even though with a higher complication rate. TAC combined with verapamil was proved to be effective with statistically significant overall improvements of scars over time and long-term stable results. TAC and 5-fluorouracil (5-FU) intralesional injections were found to achieve comparable outcomes when administered alone, although 5-FU was more frequently associated with side effects. Conversely, the combination of 5-FU and TAC was more effective and showed fewer undesirable effects compared to TAC or 5-FU alone. Several kinds of laser treatments were reported to address keloids; however, laser therapy alone was burdened with a high recurrence rate. Better results were described by combining CO2, pulsed-dye or Nd: YAG lasers with TAC intralesional injections. Further options such as needle-less intraepidermal drug delivery are being explored, but more studies are needed to establish safety, feasibility and effectiveness of this approach.

Synthesis, anti-angiogenic and DNA cleavage studies of novel N-(4-methyl-3-((4-(pyridin-3-yl)pyrimidin-2-yl)amino)phenyl)piperidine-4-carboxamide derivatives

A series of novel N-(4-methyl-3-((4-(pyridin-3-yl)pyrimidin-2-yl)amino)phenyl)piperidine-4-carboxamide derivatives 10(a-f), 12(a-c) and 14(a-c) were synthesized and characterized by FTIR, ¹H-NMR, mass spectral and elemental analysis. The efficacy of these derivatives to inhibit in vivo angiogenesis was evaluated using chick chorioallantoic membrane (CAM) model and their DNA cleavage abilities were evaluated after incubating with calf thymus DNA followed by gel electrophoresis. These novel piperidine analogues efficiently blocked the formation of blood vessels in vivo in CAM model and exhibited differential migration and band intensities in DNA binding/cleavage assays. Among the tested compounds 10a, 10b, 10c, 12b, 14b and 14c showed significant anti-angiogenic and DNA cleavage activities compared to their respective controls and the other derivatives used in this study. These observations suggest that the presence of electron donating and withdrawing groups at positions 2, 3 and 4 of the phenyl ring of the side chain may determine their potency and as anticancer agents by exerting both anti-angiogenic and cytotoxic effects .

Nitroxides as Antioxidants and Anticancer Drugs

Nitroxides are stable free radicals that contain a nitroxyl group with an unpaired electron. In this paper, we present the properties and application of nitroxides as antioxidants and anticancer drugs. The mostly used nitroxides in biology and medicine are a group of heterocyclic nitroxide derivatives of piperidine, pyrroline and pyrrolidine. The antioxidant action of nitroxides is associated with their redox cycle. Nitroxides, unlike other antioxidants, are characterized by a catalytic mechanism of action associated with a single electron oxidation and reduction reaction. In biological conditions, they mimic superoxide dismutase (SOD), modulate hemoprotein’s catalase-like activity, scavenge reactive free radicals, inhibit the Fenton and Haber-Weiss reactions and suppress the oxidation of biological materials (peptides, proteins, lipids, etc.). The use of nitroxides as antioxidants against oxidative stress induced by anticancer drugs has also been investigated. The application of nitroxides and their derivatives as anticancer drugs is discussed in the contexts of breast, hepatic, lung, ovarian, lymphatic and thyroid cancers under in vivo and in vitro experiments. In this article, we focus on new natural spin-labelled derivatives such as camptothecin, rotenone, combretastatin, podophyllotoxin and others. The applications of nitroxides in the aging process, cardiovascular disease and pathological conditions were also discussed.

Comparison of Intralesional Triamcinolone Acetonide, 5-Fluorouracil, and Their Combination for the Treatment of Keloids

Objective: Despite the myriad options available, there is no universally accepted treatment for keloids. Our objective was to compare three regimens and establish superiority in terms of objective and subjective outcomes. Approach: In this randomized parallel group study, 60 patients were enrolled and randomly allocated to three groups. Patients received intralesional injections of triamcinolone acetonide (TAC) in Group TAC, 5-fluorouracil (5FU) in Group 5FU, and a combination in Group T + F every 3 weeks till 24 weeks or till the keloid resolved. Results: There was a reduction in all parameters at every successive assessment in all three groups. Improvement in terms of height, vascularity, and pliability was fastest with 5FU, TAC, and T + F group, respectively, which was statistically significant. Decrease in pigmentation was significantly faster with T+F. Reduction in pruritus, however, was significantly faster with 5FU than the other groups, but the difference in reduction of pain among the three groups was not significant. Telangiectasias and skin atrophy were seen most commonly in TAC group, while skin ulceration was a common problem in 5FU group. Conclusion: TAC, 5FU, and their combination are all effective in keloid scars. A combination of TAC +5FU seems to offer the balanced benefit of faster and more efficacious response with lesser adverse effects when compared to individual drugs.

5-Fluorouracil Treatment Alters the Efficiency of Translational Recoding

5-fluorouracil (5-FU) is a chemotherapeutic agent that has been extensively studied since its initial development in the 1950s. It has been suggested that the mechanism of action of 5-FU involves both DNA- and RNA-directed processes, but this has remained controversial. In this study, using a series of in vivo reporter constructs capable of measuring translational recoding, we demonstrate that cells exposed to 5-FU display a reduced capacity to engage in a variety of translational recoding events, including +1 programmed frameshifting (PRF) and −1 PRF. In addition, 5-FU-treated cells are much less accurate at stop codon recognition, resulting in a significant increase in stop codon-readthrough. Remarkably, while the efficiency of cap-dependent translation appears to be unaffected by 5-FU, 5-FU-treated cells display a decreased ability to initiate cap-independent translation. We further show that knockdown of thymidylate synthase, an enzyme believed to be at the center of 5-FU-induced DNA damage, has no effect on the observed alterations in translational recoding. On the other hand, ribosomal RNA (rRNA) pseudouridylation, which plays an important role in translational recoding, is significantly inhibited. Taken together, our results suggest that the observed effect of 5-FU on recoding is an RNA-directed effect. Our results are the first to show definitely and quantitatively that translational recoding is affected by exposure to 5-FU. Thus, it is possible that a substantial portion of 5-FU cytotoxicity might possibly be the result of alterations in translational recoding efficiency.

Analysis of molecular mechanisms of 5-fluorouracil-induced steatosis and inflammation in vitro and in mice

Chemotherapy-associated steatohepatitis is attracting increasing attention because it heralds an increased risk of morbidity and mortality in patients undergoing surgery because of liver metastases. The aim of this study was to develop in vitro and in vivo models to analyze the pathogenesis of 5-fluorouracil (5-FU)-induced steatohepatitis.

Therefore, primary human hepatocytes and HepG2 hepatoma cells were incubated with 5-FU at non-toxic concentrations up to 24 h. Furthermore, hepatic tissue of C57BL/6N mice was analyzed 24 h after application of a single 5-FU dose (200 mg/kg body weight). In vitro, incubation with 5-FU induced a significant increase of hepatocellular triglyceride levels. This was paralleled by an impairment of mitochondrial function and a dose- and time-dependently increased expression of fatty acid acyl-CoA oxidase 1 (ACOX1), which catalyzes the initial step for peroxisomal β-oxidation. The latter is known to generate reactive oxygen species, and consequently, expression of the antioxidant enzyme heme oxygenase 1 (HMOX1) was significantly upregulated in 5-FU-treated cells, indicative for oxidative stress. Furthermore, 5-FU significantly induced c-Jun N-terminal kinase (JNK) activation and the expression of pro-inflammatory genes IL-8 and ICAM-1. Also in vivo, 5-FU significantly induced hepatic ACOX1 and HMOX1 expression as well as JNK-activation, pro-inflammatory gene expression and immune cell infiltration. In summary, we identified molecular mechanisms by which 5-FU induces hepatocellular lipid accumulation and inflammation. Our newly developed models can be used to gain further insight into the pathogenesis of 5-FU-induced steatohepatitis and to develop therapeutic strategies to inhibit its development and progression.

Chemotherapy Induces Oral Mucositis in Mice Without Additional Noxious Stimuli

Oral mucositis (OM) is a serious side effect of cancer chemotherapy. The pathobiology of oral mucositis remains incompletely understood due to lack of appropriate models which recapitulate the human condition. Existing rodent models are intraperitoneal and require radiation, chemical or mechanical injury to the chemotherapy protocol to induce oral lesions. We aimed to develop an OM mouse model that is induced solely by chemotherapy and reproduces macroscopic, histopathologic and inflammatory characteristics of the human condition. Female C57BL/6 mice were given intravenous 5-Fluorouracil (5-FU) injections every 48 hours, for 2 weeks. A high daily dose of intraperitoneal administration was tested for comparison. Mice were monitored daily for weight loss. Epithelial histomorphometric analyses in tongue, esophageal and intestinal tissues were conducted coupled with assessment of apoptosis, cell proliferation, neutrophilic infiltration and the integrity of adherens junctions by immunohistochemistry. Neutropenia was assessed in peripheral blood and bone marrow. Tissues were analyzed for pro-inflammatory cytokines at the protein and mRNA levels. Daily intraperitoneal administration of 5-FU led to rapid weight loss and intestinal mucositis, but no oral inflammatory changes. Intravenous administration triggered atrophy of the oral and esophageal epithelium accompanied by reduction in cell proliferation and increased apoptosis. Coincidental with these changes were up-regulation of NF-κB, TNFα, IL-1β, GM-CSF, IL-6 and KC. Despite neutropenia, increased oral neutrophilic infiltration and reduced E-cadherin was observed in oroesophageal mucosae. We developed a novel experimental tool for future mechanistic studies on the pathogenesis of chemotherapy-induced OM.

Fluorouracil Enhances Photodynamic Therapy of Squamous Cell Carcinoma via a p53-Independent Mechanism that Increases Protoporphyrin IX levels and Tumor Cell Death

Photodynamic therapy (PDT), using 5-aminolevulinic acid (ALA) to drive synthesis of protoporphryin IX (PpIX) is a promising, scar-free alternative to surgery for skin cancers, including squamous cell carcinoma (SCC) and SCC precursors called actinic keratoses. In the United States, PDT is only FDA approved for treatment of actinic keratoses; this narrow range of indications could be broadened if PDT efficacy were improved. Toward that goal, we developed a mechanism-based combination approach using 5-fluorouracil (5-FU) as a neoadjuvant for ALA-based PDT. In mouse models of SCC (orthotopic UV-induced lesions, and subcutaneous A431 and 4T1 tumors), pretreatment with 5-FU for 3 days followed by ALA for 4 hours led to large, tumor-selective increases in PpIX levels, and enhanced cell death upon illumination. Several mechanisms were identified that might explain the relatively improved therapeutic response. First, the expression of key enzymes in the heme synthesis pathway was altered, including upregulated coproporphyrinogen oxidase and downregulated ferrochelatase. Second, a 3- to 6-fold induction of p53 in 5-FU-pretreated tumors was noted. The fact that A431 contains a mutant form p53 did not prevent the development of a neoadjuvantal 5-FU effect. Furthermore, 5-FU pretreatment of 4T1 tumors (cells that completely lack p53), still led to significant beneficial inductions, that is, 2.5-fold for both PpIX and PDT-induced cell death. Thus, neoadjuvantal 5-FU combined with PDT represents a new therapeutic approach that appears useful even for p53-mutant and p53-null tumors. Mol Cancer Ther; 16(6); 1092-101. ©2017 AACR.

New frontiers in the treatment of colorectal cancer: Autophagy and the unfolded protein response as promising targets

Colorectal cancer (CRC), despite numerous therapeutic and screening attempts, still remains a major life-threatening malignancy. CRC etiology entails both genetic and environmental factors. Macroautophagy/autophagy and the unfolded protein response (UPR) are fundamental mechanisms involved in the regulation of cellular responses to environmental and genetic stresses. Both pathways are interconnected and regulate cellular responses to apoptotic stimuli. In this review, we address the epidemiology and risk factors of CRC, including genetic mutations leading to the occurrence of the disease. Next, we discuss mutations of genes related to autophagy and the UPR in CRC. Then, we discuss how autophagy and the UPR are involved in the regulation of CRC and how they associate with obesity and inflammatory responses in CRC. Finally, we provide perspectives for the modulation of autophagy and the UPR as new therapeutic options for CRC treatment.

LKB1 promotes cell survival by modulating TIF-IA-mediated pre-ribosomal RNA synthesis under uridine downregulated conditions

We analyzed the mechanism underlying 5-aminoimidazole-4-carboxamide riboside (AICAR) mediated apoptosis in LKB1-null non-small cell lung cancer (NSCLC) cells. Metabolic profile analysis revealed depletion of the intracellular pyrimidine pool after AICAR treatment, but uridine was the only nucleotide precursor capable of rescuing this apoptosis, suggesting the involvement of RNA metabolism. Because half of RNA transcription in cancer is for pre-ribosomal RNA (rRNA) synthesis, which is suppressed by over 90% after AICAR treatment, we evaluated the role of TIF-IA-mediated rRNA synthesis. While the depletion of TIF-IA by RNAi alone promoted apoptosis in LKB1-null cells, the overexpression of a wild-type or a S636A TIF-IA mutant, but not a S636D mutant, attenuated AICAR-induced apoptosis. In LKB1-null H157 cells, pre-rRNA synthesis was not suppressed by AICAR when wild-type LKB1 was present, and cellular fractionation analysis indicated that TIF-IA quickly accumulated in the nucleus in the presence of a wild-type LKB1 but not a kinase-dead mutant. Furthermore, ectopic expression of LKB1 was capable of attenuating AICAR-induced death in AMPK-null cells. Because LKB1 promotes cell survival by modulating TIF-IA-mediated pre-rRNA synthesis, this discovery suggested that targeted depletion of uridine related metabolites may be exploited in the clinic to eliminate LKB1-null cancer cells.

Metabolism, Biochemical Actions, and Chemical Synthesis of Anticancer Nucleosides, Nucleotides, and Base Analogs

Nucleoside, nucleotide, and base analogs have been in the clinic for decades to treat both viral pathogens and neoplasms. More than 20% of patients on anticancer chemotherapy have been treated with one or more of these analogs. This review focuses on the chemical synthesis and biology of anticancer nucleoside, nucleotide, and base analogs that are FDA-approved and in clinical development since 2000. We highlight the cellular biology and clinical biology of analogs, drug resistance mechanisms, and compound specificity towards different cancer types. Furthermore, we explore analog syntheses as well as improved and scale-up syntheses. We conclude with a discussion on what might lie ahead for medicinal chemists, biologists, and physicians as they try to improve analog efficacy through prodrug strategies and drug combinations.

TIF-IA: An oncogenic target of pre-ribosomal RNA synthesis

Cancer cells devote the majority of their energy consumption to ribosome biogenesis, and pre-ribosomal RNA transcription accounts for 30-50% of all transcriptional activity. This aberrantly elevated biological activity is an attractive target for cancer therapeutic intervention if approaches can be developed to circumvent the development of side effects in normal cells. TIF-IA is a transcription factor that connects RNA polymerase I with the UBF/SL-1 complex to initiate the transcription of pre-ribosomal RNA. Its function is conserved in eukaryotes from yeast to mammals, and its activity is promoted by the phosphorylation of various oncogenic kinases in cancer cells. The depletion of TIF-IA induces cell death in lung cancer cells and mouse embryonic fibroblasts but not in several other normal tissue types evaluated in knock-out studies. Furthermore, the nuclear accumulation of TIF-IA under UTP down-regulated conditions requires the activity of LKB1 kinase, and LKB1-inactivated cancer cells are susceptible to cell death under such stress conditions. Therefore, TIF-IA may be a unique target to suppress ribosome biogenesis without significantly impacting the survival of normal tissues.

Heparin-appended polycaprolactone core/corona nanoparticles for site specific delivery of 5-fluorouracil

The aim of the present work is to formulate heparin-modified-polycaprolactone (HEP) core shell nanoparticles (NPs) of 5-fluorouracil (5-FU). These NPs were characterized for various in vitro parameters like particle size, zeta potential, etc. HEP NPs were found to maintain comparatively slower drug release pattern (98.9% in 96 h) than PCL NPs. Cytotoxicity studies demonstrated a massive cytotoxic potential of 5-FU-loaded HEP NPs in A549, MDA-MD-435, and SK-OV-3 cancer cell lines. Pharmacokinetic parameters were also determined in blood after IV administration of HEP NPs: AUC, C_max, MRT, and T_max values are 6096.075 ± 5.90 μg h/mL, 144.38 ± 1.52 μg/L, 58.71 ± 0.25 h, 96 ± 0.50 h, respectively and 117.92 ± 1.78, 45.35 ± 3.00, 1.2 ± 0.25, 0.5 ± 0.02 in plain 5-FU solution.

Crystal structure of 6-oxo-4-propyl-2-(propylthio)-1,6-dihydropyrimidine-5-carbonitrile, C11H15N3OS

C11H15N3OS, triclinic, P1̅ (no. 2), a = 4.6579(2) Å, b = 9.6316(5) Å, c = 13.6654(7) Å, α = 87.982(2)°, β = 87.330(2)°, γ = 78.403(2)°, V = 599.69(5) Å3, Z = 2, R gt (F) = 0.0450, wR ref (F 2 ) = 0.128, T = 100 K.

Crystal structure of 5-ethyl-6-[(3-methylphenyl)sulfanyl]pyrimidine-2,4(1H,3H)-dione, C13H14N2O2S

C13H14N2O2S, triclinic, P1̅ (no. 2), a = 4.8885(2) Å, b = 10.3414(5) Å, c = 12.6056(6) Å, α = 95.162(2)°, β = 97.487(1)°, γ = 101.494°, V = 614.73(5) Å3, Z = 2, R gt (F) = 0.0507, wR ref (F 2 ) = 0.1149, T = 100 K.

Tandem repeats of TSER significantly influence the efficacy of 5-fluorouracil in the treatment of plantar warts

AIM

To identify potential genetic risk markers associated with 5-fluorouracil (5-FU) treatment outcomes in plantar warts patients.

METHODS

In this study, 126 plantar warts patients were treated with an intralesional mixture of 5-FU, lidocaine and epinephrine. Treatment outcomes were compared with DNA mutation analysis.

RESULTS

More patients with TSER 3R/3R genotype failed 5-FU treatment than TSER 2R/3R+2R/2R (72.1 vs 43.8%; odds ratio: 3.32; 95% CI: 1.26-8.72; p = 0.013). In addition, the regression modeling identified patient age and TSER 3R allele as covariates of the risk of 5-FU treatment failure (p = 0.025).

CONCLUSION

 TSER 3R/3R of TYMS gene was found to be the major risk of treatment failure. This genetic marker provides a potential treatment stratification target to modulate 5-FU treatment in plantar wart patients.

Crystal structure of 2-[(4-fluorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-oxo-1,6-dihydropyrimidine-5-carbonitrile, C16H16FN3OS

C16H16FN3OS, triclinic, P1̅ (no. 2), a = 5.6885(3) Å, b = 9.4378(4) Å, c = 15.0736(7) Å, α = 84.037(4)°, β = 81.442(4)°, γ = 74.271(4)°, V = 768.56(7) Å3, Z = 2, R gt (F) = 0.0518, wR ref (F 2 ) = 0.1430, T = 100 K.

Crystal structures of 4-phenyl-piperazin-1-ium 6-chloro-5-ethyl-2,4-dioxopyrimidin-1-ide and 4-phenyl-piperazin-1-ium 6-chloro-5-isopropyl-2,4-dioxopyrimidin-1-ide

The title mol-ecular salts, C10H15N2 (+)·C6H6ClN2O2 (-), (I), and C10H15N2 (+)·C7H8ClN2O2 (-), (II), consist of 4-phenyl-piperazin-1-ium cations with a 6-chloro-5-ethyl-2,4-dioxopyrimidin-1-ide anion in (I) and a 6-chloro-5-isopropyl-2,4-dioxopyrimidin-1-ide anion in (II). Salt (I) crystallizes with two independent cations and anions in the asymmetric unit. In the crystal structures of both salts, the ions are linked via N-H⋯O and N-H⋯N hydrogen bonds, forming sheets which are parallel to (100) in (I) and to (001) in (II). In (I), the sheets are linked via C-H⋯Cl hydrogen bonds, forming a three-dimensional framework.

Dark Agouti rat model of chemotherapy-induced mucositis: establishment and current state of the art

Mucositis is a major oncological problem. The entire gastrointestinal and genitourinary tract and also other mucosal surfaces can be affected in recipients of radiotherapy, and/or chemotherapy. Major progress has been made in recent years in understanding the mechanisms of oral and small intestinal mucositis, which appears to be more prominent than colonic damage. This progress is largely due to the development of representative laboratory animal models of mucositis. This review focuses on the development and establishment of the Dark Agouti rat mammary adenocarcinoma model by the Mucositis Research Group of the University of Adelaide over the past 20 years to characterize the mechanisms underlying methotrexate-, 5-fluorouracil-, and irinotecan-induced mucositis. It also aims to summarize the results from studies using different animal model systems to identify new molecular and cellular markers of mucositis.

Spectroscopic investigation (FT-IR and FT-Raman), vibrational assignments, HOMO-LUMO, NBO, MEP analysis and molecular docking study of 2-[(4-chlorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-(phenylsulfanyl)-pyrimidine-5-carbonitrile, a potential chemotherapeutic agent

Vibrational spectral analysis of 2-[(4-chlorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-(phenylsulfanyl)-pyrimidine-5-carbonitrile was carried out using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry and vibrational wave numbers have been computed using density functional B3LYP method with 6-311++G(d,p)(5D,7F) as basis set. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using NBO analysis. The nonlinear optical behavior of the title compound is also theoretically predicted. From the MEP, it is evident that the negative charge covers the C≡N group and the positive region is over the phenyl and the pyrimidine rings. From the potential energy scan it is clear that the lone pairs of the sulfur atom prefer to point away from the pyrimidine ring and the C≡N group resulting with two possible minimum conformations at the N4C8S1C25 angle equal nearly 0° or 150°. Molecular docking results suggest that the compound might exhibit inhibitory activity against GPb and may act as potential anti-diabetic compound.

Synthesis of novel spin-labeled derivatives of 5-FU as potential antineoplastic agents

Chemotherapy is a general treatment option for various cancers, including lung cancer. In order to find compounds with superior bioactivity and less toxicity against lung cancer, novel spin-labeled 5-fluorouracil (5-FU) derivatives (3a-f) were synthesized and evaluated against four human tumor cell lines (A-549, DU-145, KB, and KBvin). Two promising compounds 3d and 3f exhibited IC₅₀ values of 2.76 and 2.38 μM, respectively, against non-small cell lung carcinoma cell line A-549. These compounds were twofold more cytotoxic than 5-FU and less toxic against other tested cell lines. Compound 3f exhibited seven times more selective cytotoxicity against A-549 than 5-FU. Our results suggest that compounds 3d and 3f merit further investigation for development into clinical trial candidates for non-small cell lung cancer.

Vibrational spectroscopic and molecular docking study of 2-Benzylsulfanyl-4-[(4-methylphenyl)-sulfanyl]-6-pentylpyrimidine-5-carbonitrile, a potential chemotherapeutic agent

FT-IR and FT-Raman spectra of 2-Benzylsulfanyl-4-[(4-methylphenyl)-sulfanyl]-6-pentylpyrimidine-5-carbonitrile were recorded and analyzed. The structure of the molecule has been optimized and the structural characteristics have been determined by density functional theory. The geometrical parameters (DFT) are in agreement with the XRD results. HOMO and LUMO and other chemical properties are reported. Nonlinear optical properties are reported. A detailed molecular picture of the title compound and its interactions were obtained from NBO analysis. The negative (red and yellow) regions of the MEP are related to electrophilic reactivity and the positive (blue) regions to nucleophilic reactivity, as shown in the MEP plot and the title compound has several possible sites, CN, N atom of pyrimidine ring and sulfur atoms for electrophilic attack. From the molecular docking studies it is clear that the title compound binds at the catalytic site of the substrate by weak non-covalent interactions most prominent of which are H-bonding, π-π, alkyl-π, and amide-π interactions.

Effects of 5-fluorouracil on morphology, cell cycle, proliferation, apoptosis, autophagy and ROS production in endothelial cells and cardiomyocytes

Antimetabolites are a class of effective anticancer drugs interfering in essential biochemical processes. 5-Fluorouracil (5-FU) and its prodrug Capecitabine are widely used in the treatment of several solid tumors (gastro-intestinal, gynecological, head and neck, breast carcinomas). Therapy with fluoropyrimidines is associated with a wide range of adverse effects, including diarrhea, dehydration, abdominal pain, nausea, stomatitis, and hand-foot syndrome. Among the 5-FU side effects, increasing attention is given to cardiovascular toxicities induced at different levels and intensities. Since the mechanisms related to 5-FU-induced cardiotoxicity are still unclear, we examined the effects of 5-FU on primary cell cultures of human cardiomyocytes and endothelial cells, which represent two key components of the cardiovascular system. We analyzed at the cellular and molecular level 5-FU effects on cell proliferation, cell cycle, survival and induction of apoptosis, in an experimental cardioncology approach. We observed autophagic features at the ultrastructural and molecular levels, in particular in 5-FU exposed cardiomyocytes. Reactive oxygen species (ROS) elevation characterized the endothelial response. These responses were prevented by a ROS scavenger. We found induction of a senescent phenotype on both cell types treated with 5-FU. In vivo, in a xenograft model of colon cancer, we showed that 5-FU treatment induced ultrastructural changes in the endothelium of various organs. Taken together, our data suggest that 5-FU can affect, both at the cellular and molecular levels, two key cell types of the cardiovascular system, potentially explaining some manifestations of 5-FU-induced cardiovascular toxicity.

Spectroscopic investigation (FT-IR, FT-Raman), HOMO-LUMO, NBO analysis and molecular docking study of 2-[(4-chlorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-[3-trifluoromethyl)-anilino]pyrimidine-5-carbonitrile, a potential chemotherapeutic agent

FT-IR and FT-Raman spectra of 2-[(4-chlorobenzyl)sulfanyl]-4-(2-methylpropyl)-6-[3-trifluoromethyl)-anilino]pyrimidine-5-carbonitrile were recorded and analyzed. The vibrational wave numbers were computed using DFT quantum chemical calculations. The data obtained from wave number calculations are used to assign vibrational bands obtained in infrared and Raman spectra. Potential energy distribution was done using GAR2PED program. The NH stretching wave number is red shifted by 102 cm(-1) in IR from the computed wave number, which indicates the weakening of the NH bond. The geometrical parameters (DFT) of the title compound are in agreement with the XRD results. NBO analysis, HOMO-LUMO, first hyperpolarizability and molecular electrostatic potential results are also reported. From the MEP map it is evident that the negative electrostatic potential regions are mainly localized over the CN and CF3 groups and are possible sites for electrophilic attack and positive regions are localized around NH group, indicating possible sites for nucleophilic attack. The preliminary docking results suggest that the title compound might exhibit inhibitory activity against GPb and may act as a potential anti-diabetic compound.