Transcriptional activation and cell cycle block are the keys for 5-fluorouracil induced up-regulation of human thymidylate synthase expression

Anticancer Potential of Valencia Peanut (Arachis hypogaea L.) Skin Extract against Cervical Cancer Cells In Vitro and in Nude Mouse Xenograft Models

This study investigated the impact of Valencia KK4-type peanut skin ethanolic extract (KK4-PSE) combined with cisplatin or 5-fluorouracil (5-FU) on HeLa cells in vitro and in xenograft models. At exposure times of 24, 48 and 72 h, KK4-PSE inhibited the growth of HeLa cells with a half maximal inhibitory concentration (IC50) of 79.43 ± 0.54, 55.55 ± 1.57 and 41.32 ± 0.74 µg/mL, respectively. Drug interactions evaluated by the Chou-Talalay method demonstrated that KK4-PSE enhanced antiproliferative activity of 5-FU against HeLa cells with combination index (CI) values of 0.49 (48 h) and 0.60 (72 h), indicating a synergistic effect, while KK4-PSE combined with cisplatin exhibited an additive effect (CI = 1.02) at 72 h, and an antagonistic effect at 24 and 48 h exposures (CI = 1.12 and 1.18, respectively). In nude mouse xenograft models, the combination of 5-FU and KK4-PSE markedly reduced HeLa tumor weights compared with the control and single agent treatments groups. The combination of KK4-PSE and 5-FU achieved greater tumor growth inhibition than that of the KK4-PSE-cisplatin combination. KK4-PSE mitigated hepatotoxicity induced by both cisplatin and 5-FU in nude mice. The spleen hyaloserositis was significantly reduced in the combination treatment of 5-FU and KK4-PSE. These results suggest that KK4-PSE has the potential to limit cervical cancer cell proliferation while reducing the toxicity of cisplatin and 5-FU.

New Natural Eugenol Derivatives as Antiproliferative Agents: Synthesis, Biological Evaluation, and Computational Studies

Semisynthetic modifications of natural products have bestowed us with many anticancer drugs. In the present work, a natural product, eugenol, has been modified synthetically to generate new anticancer agents. The final compounds were structurally confirmed by NMR, IR, and mass techniques. From the cytotoxicity results, compound 17 bearing morpholine was found to be the most active cytotoxic agent with IC₅₀ 1.71 (MCF-7), 1.84 (SKOV3), and 1.1 μM (PC-3) and a thymidylate synthase (TS) inhibitor with an IC₅₀ of 0.81 μM. Further cellular studies showed that compound 17 could induce apoptosis and arrest the cell cycle at the S phase in PC-3 carcinoma. The docking study strongly favors compound 17 to be a TS inhibitor as it displayed a similar interaction to 5-fluorouracil. The in silico pharmacokinetics and DFT computational studies support the results obtained from docking and biological evaluation and displayed favorable pharmacokinetic profile for a drug to be orally available. Compound 17 was found to be a promising TS inhibitor which could suppress DNA synthesis and consequently DNA damage in prostate cancer cells.

Design, synthesis and biological evaluation of new eugenol derivatives containing 1,3,4-oxadiazole as novel inhibitors of thymidylate synthase

We report the preparation and cytotoxicity of two new eugenol derivatives that contain 1,3,4-oxadiazole, as novel inhibitors of thymidylate synthase; these derivatives are shown to be promising chemotherapeutic agents.

Uncovering cancer vulnerabilities by machine learning prediction of synthetic lethality

BACKGROUND

Synthetic lethality describes a genetic interaction between two perturbations, leading to cell death, whereas neither event alone has a significant effect on cell viability. This concept can be exploited to specifically target tumor cells. CRISPR viability screens have been widely employed to identify cancer vulnerabilities. However, an approach to systematically infer genetic interactions from viability screens is missing.

METHODS

Here we describe PAn-canceR Inferred Synthetic lethalities (PARIS), a machine learning approach to identify cancer vulnerabilities. PARIS predicts synthetic lethal (SL) interactions by combining CRISPR viability screens with genomics and transcriptomics data across hundreds of cancer cell lines profiled within the Cancer Dependency Map.

RESULTS

Using PARIS, we predicted 15 high confidence SL interactions within 549 DNA damage repair (DDR) genes. We show experimental validation of an SL interaction between the tumor suppressor CDKN2A, thymidine phosphorylase (TYMP) and the thymidylate synthase (TYMS), which may allow stratifying patients for treatment with TYMS inhibitors. Using genome-wide mapping of SL interactions for DDR genes, we unraveled a dependency between the aldehyde dehydrogenase ALDH2 and the BRCA-interacting protein BRIP1. Our results suggest BRIP1 as a potential therapeutic target in ~ 30% of all tumors, which express low levels of ALDH2.

CONCLUSIONS

PARIS is an unbiased, scalable and easy to adapt platform to identify SL interactions that should aid in improving cancer therapy with increased availability of cancer genomics data.

Structural Bases for the Synergistic Inhibition of Human Thymidylate Synthase and Ovarian Cancer Cell Growth by Drug Combinations

Simple Summary

Drug combinations may help overcome drug resistance, a relevant cause of failure of ovarian cancer therapy. However, designing successful combinations requires a lengthy preclinical validation process. We have analyzed combinations of 5-fluorouracil and raltitrexed, two anticancer drugs that target thymidylate synthase, a key enzyme for the nucleotide synthesis. We have observed administration sequence specific and synergistic combined effects of the two drugs against cisplatin sensitive and resistant ovarian cancer cells. However, the focus of this work was to show that a high stability of the complex of the enzyme with the two drugs, as highlighted by X-ray crystallography, and synergistic inhibition of the enzyme represent indicators, if not prerequisites, for this drug combination to be synergistically active against sensitive and resistant ovarian cancer cells. We thus propose that structural and mechanistic information acquired during the preclinical research can help predict a successful therapeutic application of a drug combination.

Abstract

Combining drugs represent an approach to efficiently prevent and overcome drug resistance and to reduce toxicity; yet it is a highly challenging task, particularly if combinations of inhibitors of the same enzyme target are considered. To show that crystallographic and inhibition kinetic information can provide indicators of cancer cell growth inhibition by combinations of two anti-human thymidylate synthase (hTS) drugs, we obtained the X-ray crystal structure of the hTS:raltitrexed:5-fluorodeoxyuridine monophosphate (FdUMP) complex. Its analysis showed a ternary complex with both molecules strongly bound inside the enzyme catalytic cavity. The synergistic inhibition of hTS and its mechanistic rationale were consistent with the structural analysis. When administered in combination to A2780 and A2780/CP ovarian cancer cells, the two drugs inhibited ovarian cancer cell growth additively/synergistically. Together, these results support the idea that X-ray crystallography can provide structural indicators for designing combinations of hTS (or any other target)-directed drugs to accelerate preclinical research for therapeutic application.

Folic Acid-Peptide Conjugates Combine Selective Cancer Cell Internalization with Thymidylate Synthase Dimer Interface Targeting

Drug-target interaction, cellular internalization, and target engagement should be addressed to design a lead with high chances of success in further optimization stages. Accordingly, we have designed conjugates of folic acid with anticancer peptides able to bind human thymidylate synthase (hTS) and enter cancer cells through folate receptor α (FRα) highly expressed by several cancer cells. Mechanistic analyses and molecular modeling simulations have shown that these conjugates bind the hTS monomer-monomer interface with affinities over 20 times larger than the enzyme active site. When tested on several cancer cell models, these conjugates exhibited FRα selectivity at nanomolar concentrations. A similar selectivity was observed when the conjugates were delivered in synergistic or additive combinations with anticancer agents. At variance with 5-fluorouracil and other anticancer drugs that target the hTS catalytic pocket, these conjugates do not induce overexpression of this protein and can thus help combating drug resistance associated with high hTS levels.

Salicylates enhance CRM1 inhibitor antitumor activity by induction of S-phase arrest and impairment of DNA-damage repair

Chromosome region maintenance protein 1 (CRM1) mediates protein export from the nucleus and is a new target for anticancer therapeutics. Broader application of KPT-330 (selinexor), a first-in-class CRM1 inhibitor recently approved for relapsed multiple myeloma and diffuse large B-cell lymphoma, have been limited by substantial toxicity. We discovered that salicylates markedly enhance the antitumor activity of CRM1 inhibitors by extending the mechanisms of action beyond CRM1 inhibition. Using salicylates in combination enables targeting of a range of blood cancers with a much lower dose of selinexor, thereby potentially mitigating prohibitive clinical adverse effects. Choline salicylate (CS) with low-dose KPT-330 (K+CS) had potent, broad activity across high-risk hematological malignancies and solid-organ cancers ex vivo and in vivo. The K+CS combination was not toxic to nonmalignant cells as compared with malignant cells and was safe without inducing toxicity to normal organs in mice. Mechanistically, compared with KPT-330 alone, K+CS suppresses the expression of CRM1, Rad51, and thymidylate synthase proteins, leading to more efficient inhibition of CRM1-mediated nuclear export, impairment of DNA-damage repair, reduced pyrimidine synthesis, cell-cycle arrest in S-phase, and cell apoptosis. Moreover, the addition of poly (ADP-ribose) polymerase inhibitors further potentiates the K+CS antitumor effect. K+CS represents a new class of therapy for multiple types of blood cancers and will stimulate future investigations to exploit DNA-damage repair and nucleocytoplasmic transport for cancer therapy in general.

Detection of a G-Quadruplex as a Regulatory Element in Thymidylate synthase for Gene Silencing Using Polypurine Reverse Hoogsteen Hairpins

Thymidylate synthase (TYMS) enzyme is an anti-cancer target given its role in DNA biosynthesis. TYMS inhibitors (e.g., 5-Fluorouracil) can lead to drug resistance through an autoregulatory mechanism of TYMS that causes its overexpression. Since G-quadruplexes (G4) can modulate gene expression, we searched for putative G4 forming sequences (G4FS) in the TYMS gene that could be targeted using polypurine reverse Hoogsteen hairpins (PPRH). G4 structures in the TYMS gene were detected using the quadruplex forming G-rich sequences mapper and confirmed through spectroscopic approaches such as circular dichroism and NMR using synthetic oligonucleotides. Interactions between G4FS and TYMS protein or G4FS and a PPRH targeting this sequence (HpTYMS-G4-T) were studied by EMSA and thioflavin T staining. We identified a G4FS in the 5’UTR of the TYMS gene in both DNA and RNA capable of interacting with TYMS protein. The PPRH binds to its corresponding target dsDNA, promoting G4 formation. In cancer cells, HpTYMG-G4-T decreased TYMS mRNA and protein levels, leading to cell death, and showed a synergic effect when combined with 5-fluorouracil. These results reveal the presence of a G4 motif in the TYMS gene, probably involved in the autoregulation of TYMS expression, and the therapeutic potential of a PPRH targeted to the G4FS.

Identification of TYMS as a promoting factor of retroperitoneal liposarcoma progression: Bioinformatics analysis and biological evidence

Retroperitoneal liposarcoma (RLPS) is one of the most common types of retroperitoneal sarcomas, and has a high recurrence rate. There is an urgent need to further explore its pathogenesis and develop more effective treatment strategies. The aim of the present study was to identify potential driver genes of RLPS through bioinformatics analysis and molecular biology to elucidate potential targets that are suitable for further analysis for the treatment of RLPS. Differentially expressed genes (DEGs) between liposarcoma and normal fatty (NF) tissues were identified based on microarray data through bioinformatics analysis, and thymidylate synthase (TYMS) was selected from the DEGs, based on high content screening (HCS). TYMS expression was evaluated in RLPS tumor tissues and cell lines. A total of 21 RLPS tissues and 10 NF frozen tissues were used for reverse transcription-quantitative PCR, and 47 RLPS formalin-fixed specimens were used for immunohistochemical analysis. The effect of TYMS downregulation on cell proliferation, apoptosis, cell cycle progression, and cell migration and invasion were evaluated using lentivirus-mediated short hairpin RNA. The underlying mechanisms of TYMS in RLPS were examined by protein microarray and verified by western blotting. A total of 855 DEGs were identified. TYMS knockdown had the most notable effect on the proliferative capacity of RLPS cells according to the HCS results. TYMS mRNA expression levels were higher in RLPS tissues compared with NF tissues (P<0.001). TYMS expression was higher in high-grade RLPS tissues compared with low-grade RLPS tissues (P=0.003). The patients with positive TYMS expression had a worse overall survival (OS) and disease-free survival (DFS) compared with the patients with negative TYMS expression (OS, P=0.024; DFS, P=0.030). The knockdown of TYMS reduced proliferation, promoted apoptosis, facilitated cell cycle progression from G₁ to S phase, and reduced cell migration and invasion of RLPS cells. Protein microarray analysis and western blotting showed that the Janus Kinase/Signal transducers and activators of transcription pathway was downregulated following TYMS knockdown. In conclusion, TYMS expression is upregulated in RLPS tissues, and downregulation of TYMS reduces RLPS progression.

Integrated bioinformatics analysis for the screening of hub genes and therapeutic drugs in ovarian cancer

Background

Ovarian cancer (OC) ranks fifth as a cause of gynecological cancer-associated death globally. Until now, the molecular mechanisms underlying the tumorigenesis and prognosis of OC have not been fully understood. This study aims to identify hub genes and therapeutic drugs involved in OC.

Methods

Four gene expression profiles (GSE54388, GSE69428, GSE36668, and GSE40595) were downloaded from the Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) in OC tissues and normal tissues with an adjusted P-value < 0.05 and a |log fold change (FC)| > 1.0 were first identified by GEO2R and FunRich software. Next, Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analyses were performed for functional enrichment analysis of these DEGs. Then, the hub genes were identified by the cytoHubba plugin and the other bioinformatics approaches including protein-protein interaction (PPI) network analysis, module analysis, survival analysis, and miRNA-hub gene network construction was also performed. Finally, the GEPIA2 and DGIdb databases were utilized to verify the expression levels of hub genes and to select the candidate drugs for OC, respectively.

Results

A total of 171 DEGs were identified, including 114 upregulated and 57 downregulated DEGs. The results of the GO analysis indicated that the upregulated DEGs were mainly involved in cell division, nucleus, and protein binding, whereas the biological functions showing enrichment in the downregulated DEGs were mainly negative regulation of transcription from RNA polymerase II promoter, protein complex and apicolateral plasma membrane, and glycosaminoglycan binding. As for the KEGG-pathway, the upregulated DEGs were mainly associated with metabolic pathways, biosynthesis of antibiotics, biosynthesis of amino acids, cell cycle, and HTLV-I infection. Additionally, 10 hub genes (KIF4A, CDC20, CCNB2, TOP2A, RRM2, TYMS, KIF11, BIRC5, BUB1B, and FOXM1) were identified and survival analysis of these hub genes showed that OC patients with the high-expression of CCNB2, TYMS, KIF11, KIF4A, BIRC5, BUB1B, FOXM1, and CDC20 were statistically more likely to have poorer progression free survival. Meanwhile, the expression levels of the hub genes based on GEPIA2 were in accordance with those based on GEO. Finally, DGIdb database was used to identify 62 small molecules as the potentially targeted drugs for OC treatment.

Conclusions

In summary, the data may produce new insights regarding OC pathogenesis and treatment. Hub genes and candidate drugs may improve individualized diagnosis and therapy for OC in future.

Study of Thymidylate Synthase (TS) and Dihydropyrimidine Dehydrogenase (DPD) Expressions on 5-Fluorouracil in Oral Squamous Cell Carcinoma

Background: The study aims to analyze Thymidylate Synthase (TS) and Dihydropyrimidine Dehydrogenase (DPD) Expressions on 5-Fluorouracil in Oral Squamous Cell Carcinoma (OSCC). Methods: 50 oral squamous cell carcinoma samples were taken from non-treated cancer patients at Hiroshima University Dental Hospital. The patients were investigated for TS, that included 36 males and 14 females. Additionally, 31 patients were evaluated for DPD that included 22 males and 9 females. Results: The samples had also undergone clinical and pathological evaluation, immunohistochemical staining, evaluation of immune-staining, enzymatic expression, and statistical analyses. Mean age of the population was 62.1 years. Conclusion: Over-expression of TS contributes significantly to the resistance of 5-FU treatment; while inhibition of intra-tumoral DPD increases the sensitivity level. TS levels are not only predictive of 5-FU response, but also prognostic in clinical value of non-treated cancer patients.

Corilagin from longan seed: Identification, quantification, and synergistic cytotoxicity on SKOv3ip and hey cells with ginsenoside Rh2 and 5-fluorouracil

Corilagin content from different parts of longan (Dimocarpus longan Lour.) was determined by ultra performance liquid chromatography (UPLC) method. Additionally, the potential synergistic effects of corilagin + ginsenoside Rh2 (Rh2), and corilagin + 5-fluorouracil (5-FU) on ovarian cancer cells, and cancer-preventing activities, including inhibition of tyrosinase, properties of antioxidant and nitrite-scavenging, and blocking of nitrosamine synthesis were investigated. The results showed the content of corilagin from different parts of longan varied widely, while corilagin content in longan seed was high with a value of 542.15 ± 10.30 μg/g. Then the corilagin from longan seed was chosen for further study, since longan seed was easily obtained from by-product of longan fruit processing with low cost. Furthermore, the combinations of corilagin + Rh2, and corilagin + 5-FU showed an increased synergistic cytotoxicity on SKOv3ip and Hey cells. Moreover, corilagin inhibited exhibited effects of inhibiting tyrosinase, antioxidation, scavenging nitrite and blocking nitrosamine synthesis.

Quantification and expert evaluation of evidence for chemopredictive biomarkers to personalize cancer treatment

Predictive biomarkers have the potential to facilitate cancer precision medicine by guiding the optimal choice of therapies for patients. However, clinicians are faced with an enormous volume of often-contradictory evidence regarding the therapeutic context of chemopredictive biomarkers.

We extensively surveyed public literature to systematically review the predictive effect of 7 biomarkers claimed to predict response to various chemotherapy drugs: ERCC1-platinums, RRM1-gemcitabine, TYMS-5-fluorouracil/Capecitabine, TUBB3-taxanes, MGMT-temozolomide, TOP1-irinotecan/topotecan, and TOP2A-anthracyclines. We focused on studies that investigated changes in gene or protein expression as predictors of drug sensitivity or resistance. We considered an evidence framework that ranked studies from high level I evidence for randomized controlled trials to low level IV evidence for pre-clinical studies and patient case studies.

We found that further in-depth analysis will be required to explore methodological issues, inconsistencies between studies, and tumor specific effects present even within high evidence level studies. Some of these nuances will lend themselves to automation, others will require manual curation. However, the comprehensive cataloging and analysis of dispersed public data utilizing an evidence framework provides a high level perspective on clinical actionability of these protein biomarkers. This framework and perspective will ultimately facilitate clinical trial design as well as therapeutic decision-making for individual patients.

Phase Ib study of poly-epitope peptide vaccination to thymidylate synthase (TSPP) and GOLFIG chemo-immunotherapy for treatment of metastatic colorectal cancer patients

Thymidylate synthase (TS) is a tumor-associated enzyme critical for DNA replication and main 5'-fluorouracil (5'-FU) target. TSPP/VAC1 is a multi-arm trial phase-Ib trial program aimed to investigate the toxicity and biomodulatory activity of a poly-epitope-peptide vaccine to TS (TSPP) in cancer patients (pts). Here, we present the results of the TSPP/VAC1/arm C trial aimed to evaluate TSPP in combination with chemo-immunotherapy in pretreated metastatic colo-rectal cancer (mCRC) pts. Twenty-nine pts, 14 males and 15 females, received poly-chemotherapy with gemcitabine [GEM; 1,000 mg/sqm, day-1], oxaliplatin [OX; 80 mg/sqm, day-2], levofolinate [100 mg/sqm, days 1-2], bolus/infusional 5'-FU [400 mg/800 mg/sqm, days 1-2], sargramostim [50 μg, days 3-7/q30], and interleukin-2 [sc. 0.5 MIU twice a day, days 8-14/18-30] [GOLFIG-regimen]. Seventeen pts received sc. TSPP injections at escalating dosage [3 pts, 100 µg (DL-1); 3 pts, 200 µg (DL-2) and 11pts, 300 µg (DL-3)] one week after each chemotherapy cycle (concomitant module), while 10 out 12 pts received TSPP (300 µg) after 12 GOLFIG courses [dose level (DL)-0] (sequential module). TSPP MTD was not achieved. Adverse events consisted in swelling/erythema at injection sites (17 cases), G1-2 haematological (16 cases) and gastro-enteric events (12), fever, rhinitis, conjunctivitis, and poly-arthralgia and rise in auto-antibodies [ANA, ENA, c-ANCA, p-ANCA in the DL1-3 pts]. Both treatment-modules showed immunomodulating and antitumor activity (disease-control-rate, DL1-3 and DL0 were 70.6% and 83.3%, respectively) with a better survival recorded in the second group [median OS DL1-3 vs. DL0 = 8 vs. 16 mo, p = 0.049]. The promising long-term survival produced by the sequential treatment module deserves further phase II evaluation.

Inside the biochemical pathways of thymidylate synthase perturbed by anticancer drugs: Novel strategies to overcome cancer chemoresistance

Our current understanding of the mechanisms of action of antitumor agents and the precise mechanisms underlying drug resistance is that these two processes are directly linked. Moreover, it is often possible to delineate chemoresistance mechanisms based on the specific mechanism of action of a given anticancer drug. A more holistic approach to the chemoresistance problem suggests that entire metabolic pathways, rather than single enzyme targets may better explain and educate us about the complexity of the cellular responses upon cytotoxic drug administration. Drugs, which target thymidylate synthase and folate-dependent enzymes, represent an important therapeutic arm in the treatment of various human malignancies. However, prolonged patient treatment often provokes drug resistance phenomena that render the chemotherapeutic treatment highly ineffective. Hence, strategies to overcome drug resistance are primarily designed to achieve either enhanced intracellular drug accumulation, to avoid the upregulation of folate-dependent enzymes, and to circumvent the impairment of DNA repair enzymes which are also responsible for cross-resistance to various anticancer drugs. The current clinical practice based on drug combination therapeutic regimens represents the most effective approach to counteract drug resistance. In the current paper, we review the molecular aspects of the activity of TS-targeting drugs and describe how such mechanisms are related to the emergence of clinical drug resistance. We also discuss the current possibilities to overcome drug resistance by using a molecular mechanistic approach based on medicinal chemistry methods focusing on rational structural modifications of novel antitumor agents. This paper also focuses on the importance of the modulation of metabolic pathways upon drug administration, their analysis and the assessment of their putative roles in the networks involved using a meta-analysis approach. The present review describes the main pathways that are modulated by TS-targeting anticancer drugs starting from the description of the normal functioning of the folate metabolic pathway, through the protein modulation occurring upon drug delivery to cultured tumor cells as well as cancer patients, finally describing how the pathways are modulated by drug resistance development. The data collected are then analyzed using network/netwire connecting methods in order to provide a wider view of the pathways involved and of the importance of such information in identifying additional proteins that could serve as novel druggable targets for efficacious cancer therapy.

Phase I trial of thymidylate synthase poly-epitope peptide (TSPP) vaccine in advanced cancer patients

Thymidylate synthase (TS) poly-epitope peptide (TSPP) is a 27-mer peptide vaccine containing the amino acidic sequences of three epitopes with HLA-A2.1-binding motifs of TS, an enzyme overexpressed in cancer cells, which plays a crucial role in DNA repair and replication. Based on the results of preclinical studies, we designed a phase Ib trial (TSPP/VAC1) to investigate, in a dose escalation setting, the safety and the biological activity of TSPP vaccination alone (arm A) or in combination with GM-CSF and IL-2 (arm B) in cancer patients. Twenty-one pretreated metastatic cancer patients, with a good performance status (ECOG ≤ 1) and no severe organ failure or immunological disease, were enrolled in the study (12 in arm A, nine in arm B) between April 2011 and January 2012, with a median follow-up of 28 months. TSPP resulted safe, and its maximal tolerated dose was not achieved. No grade 4 toxicity was observed. The most common adverse events were grade 2 dermatological reactions to the vaccine injection, cough, rhinitis, fever, poly-arthralgia, gastro-enteric symptoms and, to a lesser extent, moderate hypertension and hypothyroidism. We detected a significant rise in auto-antibodies and TS-epitope-specific CTL precursors. Furthermore, TSPP showed antitumor activity in this group of pretreated patients; indeed, we recorded one partial response and seven disease stabilizations (SD) in arm A, and three SD in arm B. Taken together, our findings provide the framework for the evaluation of the TSPP anti-tumor activity in further disease-oriented clinical trials.

Nanocapsules for 5-fluorouracil delivery decorated with a poly(2-ethylhexyl methacrylate-co-7-(4-trifluoromethyl)coumarin acrylamide) cross-linked wall

Nanocapsules with reverse cross-linked polymer walls containing coumarin moieties are capable of encapsulating 5-fluorouracil and accomplishing a comprehensive strategy in a drug delivery system.

Internalization and stability of a thymidylate synthase Peptide inhibitor in ovarian cancer cells

Information on the cellular internalization and stability of the ovarian cancer cell growth inhibitor peptide, LSCQLYQR (LR), is vital for lead optimization. Ad-hoc-synthesized LR/fluorescent-probe conjugates were used to monitor the internalization of the peptide. Mass spectrometry was used to identify adducts resulting from the thiol reactivity of the cysteine residue in LR. A mechanistic model is proposed to explain the observed change in intracellular peptide amount over time. Structural modifications can be foreseen to improve the peptide stability.

Gene and miRNA expression profiles of hematopoietic progenitor cells vary depending on their origin

Hematopoietic progenitor cells (HPCs) from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood (G-PB), bone marrow (BM), or umbilical cord blood (CB) have differing biological properties and differing kinetics of engraftment post-transplantation, which might be explained, at least in part, by differing gene and miRNA expression patterns. To assess the differences in gene and miRNA expression, we analyzed whole genome expression profiles as well as the expression of 384 miRNAs in CD34(+) cells isolated from 18 healthy individuals (6 individuals per subtype of HPC source). We identified 43 genes and 36 miRNAs differentially expressed in the various CD34(+) cell sources. We observed that CD34(+) cells from CB and BM showed similar gene and miRNA expression profiles, whereas CD34(+) cells from G-PB had a very different expression pattern. Remarkably, 20 of the differentially expressed genes are targets of the differentially expressed miRNAs. Of note, the majority of genes differentially expressed in CD34(+) cells from G-PB are involved in cell cycle regulation, promoting the process of proliferation, survival, hematopoiesis, and cell signaling, and are targets of overexpressed and underexpressed miRNAs in CD34(+) cells from the same source. These data suggest significant differences in gene and miRNA expression among the various HPC sources used in transplantation. We hypothesize that the differentially expressed genes and miRNAs involved in cell cycle and proliferation might explain the differing kinetics of engraftment observed after transplantation of hematopoietic stem cells obtained from these different sources.

Glycyrrhetinic acid-modified chitosan nanoparticles enhanced the effect of 5-fluorouracil in murine liver cancer model via regulatory T-cells

Modified chitosan nanoparticles are a promising platform for drug, such as 5-fluorouracil (5-FU), gene, and vaccine delivery. Here, we used chitosan and hepatoma cell-specific binding molecule glycyrrhetinic acid (GA) to synthesize glycyrrhetinic acid-modified chitosan (GA-CTS). The synthetic product was confirmed by infrared spectroscopy and hydrogen nuclear magnetic resonance. By combining GA-CTS and 5-FU, we obtained a GA-CTS/5-FU nanoparticle, with a particle size of 193.7 nm, drug loading of 1.56%, and a polydispersity index of 0.003. The GA-CTS/5-FU nanoparticle provided a sustained-release system comprising three distinct phases of quick, steady, and slow release. In vitro data indicated that it had a dose- and time-dependent anticancer effect. The effective drug exposure time against hepatic cancer cells was increased in comparison with that observed with 5-FU. In vivo studies on an orthotropic liver cancer mouse model demonstrated that GA-CTS/5-FU significantly inhibited cancer cell proliferation, resulting in increased survival time. The antitumor mechanisms for GA-CTS/5-FU nanoparticle were possibly associated with an increased expression of regulatory T-cells, decreased expression of cytotoxic T-cell and natural killer cells, and reduced levels of interleukin-2 and interferon gamma.

Synthesis of glycyrrhetinic acid-modified chitosan 5-fluorouracil nanoparticles and its inhibition of liver cancer characteristics in vitro and in vivo

Nanoparticle drug delivery (NDDS) is a novel system in which the drugs are delivered to the site of action by small particles in the nanometer range. Natural or synthetic polymers are used as vectors in NDDS, as they provide targeted, sustained release and biodegradability. Here, we used the chitosan and hepatoma cell-specific binding molecule, glycyrrhetinic acid (GA), to synthesize glycyrrhetinic acid-modified chitosan (GA-CTS). The synthetic product was confirmed by Fourier transformed infrared spectroscopy (FT-IR) and ¹H-nuclear magnetic resonance (¹H-NMR). By combining GA-CTS and 5-FU (5-fluorouracil), we obtained a GA-CTS/5-FU nanoparticle, with a particle size of 217.2 nm, a drug loading of 1.56% and a polydispersity index of 0.003. The GA-CTS/5-FU nanoparticle provided a sustained release system comprising three distinct phases of quick, steady and slow release. We demonstrated that the nanoparticle accumulated in the liver. In vitro data indicated that it had a dose- and time-dependent anti-cancer effect. The effective drug exposure time against hepatic cancer cells was increased in comparison with that observed with 5-FU. Additionally, GA-CTS/5-FU significantly inhibited the growth of drug-resistant hepatoma, which may compensate for the drug-resistance of 5-FU. In vivo studies on an orthotropic liver cancer mouse model demonstrated that GA-CTS/5-FU significantly inhibited tumor growth, resulting in increased survival time.