Topical 5-fluorouracil 1% for moderate to extensive ocular surface squamous neoplasia in 73 consecutive patients: Primary versus secondary treatment

IMPORTANCE

Ocular surface squamous neoplasia (OSSN) is a spectrum of malignancies that generally includes conjunctival intraepithelial neoplasia (CIN) and squamous cell carcinoma (SCC). OSSN can be treated with topical therapies including interferon α-2b (IFN), mitomycin C (MMC), or 5-fluorouracil 1% (5FU). Recently, due to unavailability of IFN and toxicity associated with MMC, therapy has shifted towards 5FU.

OBJECTIVE

Herein, we compare the use of 5FU 1% as a primary versus (vs) secondary treatment regimen in eyes with moderate to extensive OSSN.

DESIGN SETTING AND PARTICIPANTS

Retrospective cohort study of 73 consecutive patients with unilateral moderate to extensive OSSN treated at a single tertiary ocular oncology center from 2016 to 2023. Mean follow up time was 478.2 days overall, with 283.0 days for primary 5FU group and 860.3 days for secondary 5FU group.

INTERVENTION

Topical 5FU 1% 4 times daily for 2 weeks with option for 2-weekly extension until tumor control, either as primary treatment or as secondary treatment to surgical resection, topical IFN or topical MMC, or cryotherapy.

MAIN OUTCOMES

Outcome measures included tumor response, need for additional surgery, complications, and visual outcomes.

RESULTS

A comparison (primary vs secondary treatment) revealed no difference in mean tumor basal dimension (19.6 vs 17.2 mm, P = 0.46), thickness (3.7 vs 3.4 mm, P = 0.64), or tumor extent (4.4 vs 4.5 clock hours, P = 0.92). The primary treatment group showed greater complete tumor control (77% vs 38%, P = 0.04). Multivariable analysis comparison (primary vs secondary treatment) showed primary treatment more likely to achieve complete tumor control (P = 0.01). There was no difference in the complication rate from 5FU treatment between the groups. There was no difference in visual outcome, and no tumor-related metastasis (0%) or death (0%).

CONCLUSION AND RELEVANCE

Topical 5FU 1% is efficacious and safe as a primary or secondary treatment for moderate to extensive OSSN. Tumors treated with primary 5FU 1% demonstrated more complete resolution. In patients with moderate to extensive OSSN, primary treatment with topical 5FU 1% may be warranted.

Bacterial DnaK reduces the activity of anti-cancer drugs cisplatin and 5FU

BACKGROUND

Chemotherapy is a primary treatment for cancer, but its efficacy is often limited by cancer-associated bacteria (CAB) that impair tumor suppressor functions. Our previous research found that Mycoplasma fermentans DnaK, a chaperone protein, impairs p53 activities, which are essential for most anti-cancer chemotherapeutic responses.

METHODS

To investigate the role of DnaK in chemotherapy, we treated cancer cell lines with M. fermentans DnaK and then with commonly used p53-dependent anti-cancer drugs (cisplatin and 5FU). We evaluated the cells' survival in the presence or absence of a DnaK-binding peptide (ARV-1502). We also validated our findings using primary tumor cells from a novel DnaK knock-in mouse model. To provide a broader context for the clinical significance of these findings, we investigated human primary cancer sequencing datasets from The Cancer Genome Atlas (TCGA). We identified F. nucleatum as a CAB carrying DnaK with an amino acid composition highly similar to M. fermentans DnaK. Therefore, we investigated the effect of F. nucleatum DnaK on the anti-cancer activity of cisplatin and 5FU.

RESULTS

Our results show that both M. fermentans and F. nucleatum DnaKs reduce the effectiveness of cisplatin and 5FU. However, the use of ARV-1502 effectively restored the drugs' anti-cancer efficacy.

CONCLUSIONS

Our findings offer a practical framework for designing and implementing novel personalized anti-cancer strategies by targeting specific bacterial DnaKs in patients with poor response to chemotherapy, underscoring the potential for microbiome-based personalized cancer therapies.

Intralesional Treatments for Invasive Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (cSCC) is the second most frequent cancer in humans and has the potential to progress locally, metastasize, and cause death in a subset of patients. cSCC is especially common in the elderly, and it will probably represent a major health concern in the near future. Surgery is the standard treatment for cSCC, but intralesional therapies can sometimes be considered for certain patients and under certain circumstances. The choice of intralesional treatment depends on the patient's characteristics and the clinician's previous experience and expertise. Here we are reviewing intralesional treatments for cSCC and keratoacanthoma (KA). We have started with some classic drugs, such as methotrexate and 5-fluorouracil, bleomycin, interferon, and cryosurgery, but also comment on electrochemotherapy. Finally, we have focused on novel therapies, some of which are under development, and future perspectives, including intralesional immunotherapy and oncolytic viruses.

A novel outpatient regimen in management of fluoropyrimidine-induced cardiotoxicity

INTRODUCTION

Fluoropyrimidines (FP) are cornerstone drugs in the treatment of gastrointestinal (GI) malignancies. Cardiotoxicity secondary to an FP chemotherapy is a serious complication. There are no standardized guidelines on the treatment of FP induced cardiotoxicity which may result in interruption and even discontinuation of life saving treatment. We present our experience in FP rechallenge using a novel outpatient regimen based on our "up-front" triple agent antianginal protocol.

METHODS

We report the retrospective study of the patients with suspected FP induced cardiotoxicity. Patients meeting the criteria were selected by C3OD (curated cancer clinical outcomes database) at Kansas University Medical Center (KUMC). We identified all patients with gastrointestinal malignancies who had suspected FP induced cardiotoxicity from January 2015 to March 2022. We then included the patients who were rechallenged with planned fluoropyrimidine regimen utilizing the three drug KU-protocol. We utilized a novel regimen by repurposing the already FDA-approved anti-anginal drugs in a manner that minimizes the risk of hypotension and bradycardia.

RESULTS

In this retrospective study, 10 patients with suspected fluoropyrimidine induced cardiotoxicity were included from January-2015 to March-2022 at KUMC. Out of 10 patients who were rechallenged utilizing KU-protocol, eight patients (80%) were able to complete the previously planned fluoropyrimidine regimen. None of the patients required ER visits or hospital admission due to cardiac symptoms during the rechallenge utilizing the KU-protocol.

CONCLUSIONS

Utilizing our novel outpatient regimen, we have successfully and safely allowed re-challenge of FP chemotherapy with good tolerability and completion of the intended course of chemotherapy without recurrent morbidity.

Improvement of the Genome Editing Tools Based on 5FC/5FU Counter Selection in Clostridium acetobutylicum

Several genetic tools have been developed for genome engineering in Clostridium acetobutylicum utilizing 5-fluorouracil (5FU) or 5-fluorocytosine (5FC) resistance as a selection method. In our group, a method based on the integration, by single crossing over, of a suicide plasmid (pCat-upp) followed by selection for the second crossing over using a counter-selectable marker (the upp gene and 5FU resistance) was recently developed for genome editing in C. acetobutylicum. This method allows genome modification without leaving any marker or scar in a strain of C. acetobutylicum that is ∆upp. Unfortunately, 5FU has strong mutagenic properties, inducing mutations in the strain's genome. After numerous applications of the pCat-upp/5FU system for genome modification in C. acetobutylicum, the CAB1060 mutant strain became entirely resistant to 5FU in the presence of the upp gene, resulting in failure when selecting on 5FU for the second crossing over. It was found that the potential repressor of the pyrimidine operon, PyrR, was mutated at position A115, leading to the 5FU resistance of the strain. To fix this problem, we created a corrective replicative plasmid expressing the pyrR gene, which was shown to restore the 5FU sensitivity of the strain. Furthermore, in order to avoid the occurrence of the problem observed with the CAB1060 strain, a preventive suicide plasmid, pCat-upp-pyrR*, was also developed, featuring the introduction of a synthetic codon-optimized pyrR gene, which was referred to as pyrR* with low nucleotide sequence homology to pyrR. Finally, to minimize the mutagenic effect of 5FU, we also improved the pCat-upp/5FU system by reducing the concentration of 5FU from 1 mM to 5 µM using a defined synthetic medium. The optimized system/conditions were used to successfully replace the ldh gene by the sadh-hydG operon to convert acetone into isopropanol.

Efficient delivery of anticancer 5-fluorouracil drug by alkaline earth metal functionalized porphyrin-like porous fullerenes: A DFT study

Finding and developing effective targeted drug delivery systems has emerged as an attractive approach for treating a wide range of diseases. In the present study, the potential of alkaline earth metal functionalized porphyrin-like porous C₂₄N₂₄ fullerenes for delivering 5-fluorouracil (5FU) anticancer drug is assessed using density functional theory calculations. The goal is to evaluate how the addition of alkaline earth metals to C₂₄N₂₄ enhances the adsorption capabilities of this system towards 5FU drug. The adsorption energies and charge transfers are determined in order to evaluate the strength of the interaction between the 5FU and fullerene surfaces. According to the results, adding alkaline earth metals increases the drug's adsorption energy on the C₂₄N₂₄ fullerene. In all cases, the drug molecule interacts with the metal atom through its CO group. Furthermore, the adsorption strength of the 5FU increases with metal atom size (Ca > Mg > Be), which is connected to the polarizability of these atoms. The adsorption energies of 5FU are shown to be highly sensitive on solvent effects and the acidity of the environment. The adsorption strength of 5FU decreases within the solvent (water), allowing it to be released more easily. The moderate adsorption energies and short desorption times of 5FU imply that it is reversibly adsorbed on the functionalized fullerenes.

Dihydropyrimidine dehydrogenase phenotype in peripheral blood mononuclear cells is related to adverse events of fluoropyrimidine-therapy

PURPOSE

The primary objective of this study was to determine if dihydropyrimidine dehydrogenase (DPD) activity measured in peripheral blood mononuclear cells (PBMCs) is related to adverse events during fluoropyrimidine therapy.

METHODS

A retrospective cohort study was conducted. The study population included 481 patients who received fluoropyrimidine treatment and for whom relevant patient characteristics were known and adverse events were noted in the electronic health records. Factors besides DPD phenotype that could affect the incidence of adverse events were corrected for using log regression. These log regression models were used to identify an association between the DPD phenotype measured in PBMCs and adverse events.

RESULTS

Patients with a decreased DPD activity measured in PBMCs suffered more adverse events. Results from log regression data show that this effect remains significant after correcting for dosage, chemotherapy regimen and relevant patient characteristics.

CONCLUSION

A significant correlation was found between reduced DPD enzyme activity in PBMCs and adverse events. The findings in this paper support further exploring DPD phenotyping as a method for preventing fluoropyrimidine-related adverse events. Further assessment of DPD phenotyping will require clinical validation in a prospective study.

The Novel 5-Fluorouracil Loaded Ruthenium-based Nanocarriers Enhanced Anticancer and Apoptotic Efficiency while Reducing Multidrug Resistance in Colorectal Cancer Cells

Recently, nanocarriers have been made to eliminate the disadvantages of chemotherapeutic agents by nanocarriers. Nanocarriers show their efficacy through their targeted and controlled release. In this study, 5-fluorouracil (5FU) was loaded into ruthenium (Ru)-based nanocarrier (5FU-RuNPs) for the first time to eliminate the disadvantages of 5FU, and its cytotoxic and apoptotic effects on HCT116 colorectal cancer cells were compared with free 5FU. 5FU-RuNPs with a size of approximately 100 nm showed a 2.61-fold higher cytotoxic effect compared to free 5FU. Apoptotic cells were detected by Hoechst/propidium iodide double staining, and the expression levels of BAX/Bcl-2 and p53 proteins, in which apoptosis occurred intrinsically, were revealed. In addition, 5FU-RuNPs was also found to reduce multidrug resistance (MDR) according to BCRP/ABCG2 gene expression levels. When all the results were evaluated, the fact that Ru-based nanocarriers alone did not cause cytotoxicity proved that they were ideal nanocarriers. Moreover, 5FU-RuNPs did not show any significant effect on the cell viability of normal human epithelial cell lines BEAS-2B. Consequently, the 5FU-RuNPs synthesized for the first time may be ideal candidates for cancer treatment because they can minimize the potential drawbacks of free 5FU.

Effect of Ionization Degree of Poly(amidoamine) Dendrimer and 5-Fluorouracil on the Efficiency of Complex Formation-A Theoretical and Experimental Approach

Due to their unique structure, poly(amidoamine) (PAMAM) dendrimers can bind active ingredients in two ways: inside the structure or on their surface. The location of drug molecules significantly impacts the kinetics of active substance release and the mechanism of internalization into the cell. This study focuses on the effect of the protonation degree of the G4PAMAM dendrimer and the anticancer drug 5-fluorouracil (5FU) on the efficiency of complex formation. The most favorable conditions for constructing the G4PAMAM-5FU complex are a low degree of protonation of the dendrimer molecule with the drug simultaneously present in a deprotonated form. The fluorine components in the XPS spectra confirm the formation of the stable complex. Through SAXS and DLS methods, a decrease in the dendrimer's molecular size resulting from protonation changes at alkaline conditions was demonstrated. The gradual closure of the dendrimer structure observed at high pH values makes it difficult for the 5FU molecules to migrate to the interior of the support structure, thereby promoting drug immobilization on the surface. The ¹H NMR and DOSY spectra indicate that electrostatic interactions determine the complex formation process. Through MD simulations, the localization profile and the number of 5FU molecules forming the complex were visualized on an atomic scale.

Binding mechanism and SERS spectra of 5-fluorouracil on gold clusters

The adsorption behaviour of the 5-fluorouracil (5FU) on small gold clusters Au _N with N = 6, 8, 20 was evaluated by means of density functional theory using the PBE-D3 functional in combination with a mixed basis set, i.e. cc-pVDZ-PP for gold atoms and cc-pVTZ for non-metal elements. The binding energies between 5FU and gold clusters were determined in the range of 16-24 and 11-19 kcal/mol in gas-phase and aqueous media, respectively. The corresponding Gibbs energies were found to be around -7 to -10 kcal/mol in vacum and sigificantly reduced to -1 to -6 kcal/mol in water solution, indicating that both the association and dissociation processes are likely spontaneous. An analysis on the charge density difference tends to confirm the existence of a charge transfer from the 5FU molecule to Au atoms. Analysis of the surface-enhanced Raman scattering (SERS) spectra of 5FU adsorbed on the Au surfaces shows that the stretching vibrations of N-H and C=O bonds play a major role in the SERS phenomenon. A mechanism for the drug releasing from the gold surfaces is also proposed. The process is triggered by either the low pH in cancerous tumors or the presence of cysteine residues in protein matrices.

Efficacy and safety of combined fractional ablative CO2 laser and 5 fluorouracil in the treatment of acral vitiligo: An open, uncontrolled study

BACKGROUND

Acral lesions of vitiligo are most likely recalcitrant to the known lines of treatment. Ablative fractional CO₂ has shown efficacy in treatment of vitiligo in combination with other modalities.

METHODS

Thirty non-segmental vitiligo patients with acral lesion were included in the study. Each patient was subjected to fractional Carbon Dioxide Laser Treatment followed by application of 5 fluorouracil (5FU) cream for five consecutive days. Evaluation was done 3 weeks from the start of treatment and 12 weeks after the last treatment session using VESTA score, evaluation of patients' photos by blinded investigation in addition to patients' satisfaction scores.

RESULTS

Patients showed significant improvement of Vitiligo extent score for a target area (VESTA) score and developed considerable degree of repigmentation as assessed by blinded investigators.

CONCLUSION

The combination of fractional ablative CO₂ and 5FU is an effective and safe procedure for the treatment of acral vitiligo with promising results offering patients a new therapeutic window.

Formulation and Evaluation of Chitosan-Gelatin Thermosensitive Hydrogels Containing 5FU-Alginate Nanoparticles for Skin Delivery

(1) Background: Chitosan-gelatin-based thermosensitive hydrogel containing 5FU-alginate nanoparticles was formulated for the effective and sustained delivery of 5FU to the skin. (2) Methods: Alginate, a polysaccharide was used for the formulation of nanoparticles using a spray drying technique. Size, zeta potential, and surface morphology were investigated using a zetasizer and scanning electron microscope. The hydrogel was fabricated using chitosan and gelatin. Several important analyses were used to characterize these prepared topical hydrogels. The pH, visual transparency, rheological behavior, and swelling index of the prepared hydrogels were evaluated. The in vitro release studies were performed at different pH (5.5 and 7.4) and temperature (32 and 37 °C) conditions using a Franz diffusion cell. Ex vivo permeation and in vivo studies were performed using Sprague Dawley rats. (3) Results: Results show that spherical nanoparticles were produced at sizes of 202−254 nm and with zeta potentials of −43 to −38 mV. The prepared nanoparticles were successfully incorporated into chitosan-gelatin-based hydrogels using a glycerol 2-phosphate disodium salt hydrates crosslinker. Drug polymers and excipients compatibility and formulation of hydrogels was confirmed by ATR-FTIR results. The pH of the prepared hydrogels was in accordance with the skin pH. The viscosity of prepared hydrogel increased with temperature increase and phase transition (sol-gel transition) occurred at 34 °C. The release of drug was sustained in case of nanoparticles incorporated hydrogels (5FU-Alg-Np-HG) as compared to nanoparticles (5FU-Alg-Np) and simple hydrogels (5FU-HG) (ANOVA; p < 0.05). The premature and initial burst release of 5FU was prevented using 5FU-Alg-Np-HG. The release mechanism of 5FU from the 5FU-Alg-Np-HG diffusion was followed by swelling and erosion, as suggested by Korsmeyer-Peppas model. The prepared hydrogel proved to be non-irritant. Ex vivo permeation study across rat’s skin suggests that permeability of nanoparticles (5FU-Alg-Np) was higher than the 5FU-Alg-Np-HG (ANOVA; p < 0.05). However, skin-related drug retention of 5FU-Alg-Np-HG was significantly higher than the 5FU solution, 5FU-Alg-Np, and 5FU-HG (ANOVA; p < 0.05). This was due to swelling of hydrogels in the lower layers of skin where the temperature is 37 °C. The higher concentration of 5FU in the skin is helpful for treatment of local skin cancer, such as melanoma, and actinic keratosis. In vivo results also confirmed maximum AUC, t1/2, and skin-related drug retention of 5FU-Alg-Np-HG. (4) Conclusions: Chitosan-gelatin-based hydrogels containing 5FU-Alg-Np possess exceptional properties, and can be used for the sustained delivery of 5FU for the treatment of local skin cancers.

The evaluation of anticancer activity by synthesizing 5FU loaded albumin nanoparticles by exposure to UV light

In this study, as a new synthesis method, UV light was employed as a type of cross-linking agent to control drug storage and to produce nanoparticles of different sizes and to stabilize the nanoparticles for the first time. We showed that the exposure time of the 5FU albumin solution to UV light produces differences in the size and characterization of the nanoparticles and also produces different cytotoxic effects on MCF-7 breast cancer cells. While the 5FU-A1 nanoparticles we synthesized with 1 h UV storage were approximately 43 nm, the 5FU-A2 nanoparticles we synthesized with UV storage for 3 h increased to an average of 300 nm. 5FU-A1 (IC₅₀ value: 2.5 μg/mL) was approximately 16 times more cytotoxic than free 5FU (IC₅₀ value 39.39 μg/mL) on MCF-7 cancer cells. Moreover, when normal HUVEC cells are treated with 5FU-A1 at a concentration of 2.5 μg/mL, more than 80% of these normal cells remain viable. In addition, we examined the rate of early-to-late apoptosis and necrosis in MCF-7 cancer cells using the Annexin V/PI flow cytometry assay. According to our results, 5FU-A1 promoted the apoptosis pathway. Finally, we examined P-gp activity with MDR1/ABCB1 antibody by flow cytometry and Rhodamine123 with fluorescent dye.

Folate-Modified Chitosan 5-Flourouraci Nanoparticles-Embedded Calcium Alginate Beads for Colon Targeted Delivery

Gel beads are formed when alginate acid reacts with divalent cations, particularly Ca²⁺. As a result of this feature, it is one of the best materials for making gel beads. Furthermore, it swells only slightly at acidic pH, resulting in stable alginate acid beads, but swells and dissolves rapidly at higher pH values, leading to pH-responsive release. Our current study aimed to embed folate-modified chitosan 5FU nanoparticles (FA-CS-5FU-NPs) into calcium alginate beads for colon-targeted delivery. Calcium alginate beads were developed successfully. Based on the method of drying, two types of beads were obtained: freeze-dried folate-modified chitosan 5FU nanoparticles-embedded beads (FA-CS-5FU-NP-Bf) and oven-dried folate-modified chitosan 5FU nanoparticles-embedded beads (FA-CS-5FU-NP-Bo). The size of (FA-CS-5FU-NP-Bf) was significantly larger than (FA-CS-5FU-NP-Bo). Swelling index (SI), erosion index (EI), and water-uptake index (WUI) of (FA-CS-5FU-NP-Bf) beads were significantly higher than FA-CS-5FU-NP-Bo beads at simulated intestinal pH. An insignificant difference was observed in the release rate of 5FU between (FA-CS-5FU-NP-Bf) and FA-CS-5FU-NP-Bo. The release rate of FA-CS-5FU-NPs was significantly higher than FA-CS-5FU-NP-Bf and FA-CS-5FU-NP-Bo. Pharmacokinetic parameters of 5FU solution, FA-CS-5FU-NPs, and FA-CS-5FU-NP-Bo were analyzed. Solution of pure 5FU showed significantly higher C_max and lower AUC, T_1/2, and Vd than both FA-CS-5FU-NPs and FA-CS-5FU-NPs-Bo, suggesting that FA-CS-5FU-NPs and FA-CS-5FU-NPs-Bo have sustained-release behavior. Biodistribution studies also show that maximum drug amounts were found in the colon from nanoparticles-embedded beads. FA-CS-5FU-NPs-Bo avoid releasing drugs in the stomach and small intestine and make them available in the colon region in higher concentrations to target the colon region specifically.

GZ17-6.02 and palbociclib interact to kill ER+ breast cancer cells

GZ17-6.02 is presently undergoing clinical evaluation in solid tumors and lymphoma. The present studies were performed to define its biology in estrogen receptor positive breast cancer cells and to determine whether it interacted with palbociclib to enhance tumor cell killing. GZ17-6.02 interacted in an additive fashion with palbociclib to kill ER+ breast cancer cells. GZ17-6.02 and palbociclib cooperated to inactivate mTOR and AKT and to activate ULK1 and PERK. The drugs interacted to increase the expression of FAS-L and BAX, and to decrease the levels of MCL1, the estrogen receptor, and HDACs 1–3. Palbociclib activated ERBB3, an effect blocked by GZ17-6.02. GZ17-6.02 and palbociclib interacted to increase the expression of multiple toxic BH3 domain proteins and to reduce MCL1 and BCL-XL expression. Knock down of FAS-L reduced the lethality of [GZ17-6.02 + palbociclib]. GZ17-6.02 and palbociclib interacted to enhance autophagosome formation and autophagic flux. Knock down of Beclin1, ATG5, BAG3, eIF2α, toxic BH3 domain proteins or CD95 significantly reduced drug combination lethality. GZ17-6.02 and palbociclib increased the expression of Beclin1 and ATG5, effects blocked by knock down of eIF2α. The drugs also increased the phosphorylation of the AMPK and ATG13, effects blocked by knock down of ATM. Knock down of ATM or the AMPK, or expression of activated mTOR significantly reduced the abilities of GZ17-6.02 and palbociclib to enhance autophagosome formation and autophagic flux.

Tumor-Specific Delivery of 5-Fluorouracil-Incorporated Epidermal Growth Factor Receptor-Targeted Aptamers as an Efficient Treatment in Pancreatic Ductal Adenocarcinoma Models

BACKGROUNDS & AIMS

Fluoropyrimidine c (5-fluorouracil [5FU]) increasingly represents the chemotherapeutic backbone for neoadjuvant, adjuvant, and palliative treatment of pancreatic ductal adenocarcinoma (PDAC). Even in combination with other agents, 5FU efficacy remains transient and limited. One explanation for the inadequate response is insufficient and nonspecific delivery of 5FU to the tumor.

METHODS

We designed, generated, and characterized 5FU-incorporated systematic evolution of ligands by exponential enrichment (SELEX)-selected epidermal growth factor receptor (EGFR)-targeted aptamers for tumor-specific delivery of 5FU to PDAC cells and tested their therapeutic efficacy in vitro and in vivo.

RESULTS

5FU-EGFR aptamers reduced proliferation in a concentration-dependent manner in mouse and human pancreatic cancer cell lines. Time-lapsed live imaging showed EGFR-specific uptake of aptamers via clathrin-dependent endocytosis. The 5FU-aptamer treatment was equally effective in 5FU-sensitive and 5FU-refractory PDAC cell lines. Biweekly treatment with 5FU-EGFR aptamers reduced tumor burden in a syngeneic orthotopic transplantation model of PDAC, in an autochthonously growing genetically engineered PDAC model (LSL-KrasG12D/+;LSL-Trp53flox/+;Ptf1a-Cre [KPC]), in an orthotopic cell line-derived xenograft model using human PDAC cells in athymic mice (CDX; Crl:NU-Foxn1nu), and in patient-derived organoids. Tumor growth was significantly attenuated during 5FU-EGFR aptamer treatment in the course of follow-up.

CONCLUSIONS

Tumor-specific targeted delivery of 5FU using EGFR aptamers as the carrier achieved high target specificity; overcame 5FU resistance; and proved to be effective in a syngeneic orthotopic transplantation model, in KPC mice, in a CDX model, and in patient-derived organoids and, therefore, represents a promising backbone for pancreatic cancer chemotherapy in patients. Furthermore, our approach has the potential to target virtually any cancer entity sensitive to 5FU treatment by incorporating 5FU into cancer cell-targeting aptamers as the delivery platform.

Mice with dysfunctional TGF-β signaling develop altered intestinal microbiome and colorectal cancer resistant to 5FU

Emerging data show a rise in colorectal cancer (CRC) incidence in young men and women that is often chemoresistant. One potential risk factor is an alteration in the microbiome. Here, we investigated the role of TGF-β signaling on the intestinal microbiome and the efficacy of chemotherapy for CRC induced by azoxymethane and dextran sodium sulfate in mice. We used two genotypes of TGF-β-signaling-deficient mice (Smad4^+/- and Smad4^+/-Sptbn1^+/-), which developed CRC with similar phenotypes and had similar alterations in the intestinal microbiome. Using these mice, we evaluated the intestinal microbiome and determined the effect of dysfunctional TGF-β signaling on the response to the chemotherapeutic agent 5-Fluoro-uracil (5FU) after induction of CRC. Using shotgun metagenomic sequencing, we determined gut microbiota composition in mice with CRC and found reduced amounts of beneficial species of Bacteroides and Parabacteroides in the mutants compared to the wild-type (WT) mice. Furthermore, the mutant mice with CRC were resistant to 5FU. Whereas the abundances of E. boltae, B.dorei, Lachnoclostridium sp., and Mordavella sp. were significantly reduced in mice with CRC, these species only recovered to basal amounts after 5FU treatment in WT mice, suggesting that the alterations in the intestinal microbiome resulting from compromised TGF-β signaling impaired the response to 5FU. These findings could have implications for inhibiting the TGF-β pathway in the treatment of CRC or other cancers.

Bio- and Hemo-Compatible Silk Fibroin PEGylated Nanocarriers for 5-Fluorouracil Chemotherapy in Colorectal Cancer: In Vitro Studies

5-fluorouracil (5-FU) remains the gold standard of treatment for colorectal cancer, but its poor bioavailability and high systemic toxicity highlight the urgent need for the development of novel delivery strategies to increase the efficacy of 5-FU treatment. The present study is aimed to design and validate a PEGylated Silk Fibroin Nanocarrier (SF/PEG nanoparticles (NPs)) as an efficient 5-FU delivery system for potential intravenous administration. Using the human adenocarcinoma HT–29 cell line as an in vitro model for colorectal cancer, the cytotoxicity screening of the SF/PEG NPs showed that pristine nanocarriers were highly biocompatible, while the addition of 5-FU triggers a dramatic reduction in tumor cell viability, proliferation potential and mitochondrial integrity as well as a significant increase in nitric oxide production. Despite their high in vitro cytotoxicity, the 5-FU SF/PEG NPs were found hemocompatible as no impact on red blood cells hemolysis or the phagocytic activity of the granulocytes was observed. Exposure of HT–29 tumor cells and blood samples to 5-FU SF/PEG NPs augmented the tumor necrosis factor-α levels. Moreover, 5-FU SF/PEG NPs showed an impact on tumor cell migration and invasive potential as both of these processes were inhibited by the NP treatment.

Chemosensitization of HT29 and HT29-5FU Cell Lines by a Combination of a Multi-Tyrosine Kinase Inhibitor and 5FU Downregulates ABCC1 and Inhibits PIK3CA in Light of Their Importance in Saudi Colorectal Cancer

Colorectal cancer (CRC) remains one of the main causes of death worldwide and in Saudi Arabia. The toxicity and the development of resistance against 5 fluorouracil 5FU pose increasing therapeutic difficulties, which necessitates the development of personalized drugs and drug combinations. Objectives: First, to determine the most important kinases and kinase pathways, and the amount of ABC transporters and KRAS in samples taken from Saudi CRC patients. Second, to investigate the chemosensitizing effect of LY294002 and HAA₂₀₂₀ and their combinations with 5FU on HT29, HT29-5FU, HCT116, and HCT116-5FU CRC cells, their effect on the three ABC transporters, cell cycle, and apoptosis, in light of the important kinase pathways resulting from the first part of this study. Methods: The PamChip^® peptide micro-array profiling was used to determine the level of kinase and targets in the Saudi CRC samples. Next, RT-PCR, MTT cytotoxicity, Western blotting, perturbation of cell cycle, annexin V, and immunofluorescence assays were used to investigate the effect on CRC, MRC5, and HUVEC cells. Results: The kinase activity profiling highlighted the importance of the PI3K/AKT, MAPK, and the growth factors pathways in the Saudi CRC samples. PIK3CA was the most overexpressed, and it was associated with increased level of mutated KRAS and the three ABC transporters, especially ABCC1 in the Saudi samples. Next, combining HAA₂₀₂₀ with 5FU exhibited the best synergistic and resistance-reversal effect in the four CRC cells, and the highest selectivity indices compared to MRC5 and HUVEC normal cells. Additionally, HAA₂₀₂₀ with 5FU exerted significant inhibition of ABCC1 in the four CRC cells, and inhibition of PIK3CA/AKT/MAPK7/ERK in HT29 and HT29-5FU cells. The combination also inhibited EGFR, increased the preG₁/S cell cycle phases, apoptosis, and caspase 8 in HT29 cells, while it increased the G₁ phase, p21/p27, and apoptosis in HT29-5FU cells. Conclusion: We have combined the PamChip kinase profiling of Saudi CRC samples with in vitro drug combination studies in four CRC cells, highlighting the importance of targeting PIK3CA and ABCC1 for Saudi CRC patients, especially given that the overexpression of PIK3CA mutations was previously linked with the lack of activity for the anti-EGFRs as first line treatment for CRC patients. The combination of HAA₂₀₂₀ and 5FU has selectively sensitized the four CRC cells to 5FU and could be further studied.

Inhibitory effect of Ubenimex combined with fluorouracil on multiple drug resistance and P-glycoprotein expression level in non-small lung cancer

Tumour drug resistance is one of the most urgent issues faced by anti‐tumour therapies. P‐glycoprotein (P‐gp) has been reported to be correlated with drug resistance. In this study, we aimed to study the synergistic effect of fluorouracil (5FU) and Ubenimex (UBE) on drug resistance in lung cancer. In this study, the tumour inhibitory role of 5FU and UBE was assessed in nude mice bearing A549 or A549/ADR. Real‐time polymerase chain reaction, Western blot and immunohistochemical were performed to analyse the mRNA and protein expression of P‐gp. TUNEL assay was used to evaluate the apoptosis of A549/ADR cells under 5FU and UBE treatment. MTT assay was performed to calculate the IC50 value of 5FU and UBE in A549 or A549/ADR. Combined administration of 5FU and UBE significantly inhibited the tumour growth of multidrug‐resistant cell lines A549/ADR in nude mice by down‐regulating the mRNA and protein expression of P‐gp. The apoptosis of A549/ADR was remarkably elevated in nude mice treated with 5FU and UBE. The IC50 value of 5FU and UBE was dramatically declined in A549/ADR cells compared with that of 5FU or UBE alone. Combined treatment of 5FU and UBE remarkably enhanced the apoptosis of A549/ADR cells by enhancing the intracellular accumulation of the drugs. The results of this study demonstrated that UBE combined with fluorouracil attenuated multiple drug resistance and inhibited the expression of P‐gp in lung cancer.

The use of 5-fluorouracil in the prevention of tendon adhesions: A systematic review

BACKGROUND

This systematic review aims to study the effectiveness of 5-fluorouracil (5FU) in the reduction of tendon adhesions postsurgical repair.

METHOD

A systematic review was performed involving four databases, Cochrane, PubMed, MEDLINE, and Embase, looking for evidence of at least Level I or Level II (according to NHMRC) in the use of 5FU in tendon repairs in human or animal studies.

RESULTS

Across the four databases 546 articles were identified. Of these 12 were identified as relevant, with a further two being excluded after in depth review.

CONCLUSIONS

Nine of the 10 studies showed that 5FU was effective at reducing tendon adhesions in their respective animal studies. One of the 10 studies showed no significant change compared to the control group.

(Curcumin+sildenafil) enhances the efficacy of 5FU and anti-PD1 therapies in vivo

We have extended our analyses of (curcumin+sildenafil) biology. The drug combination caused vascularization and degradation of mutant K-RAS that correlated with reduced phosphorylation of ERK1/2, AKT T308, mTORC1, mTORC2, ULK1 S757, STAT3, STAT5, and NFκB and increased phosphorylation of eIF2α, ATM, AMPKα, ULK1 S317; all concomitant with elevated ATG13 S318 phosphorylation and autophagosome formation. Prior studies with drug combinations utilizing sildenafil have delineated an ATM-AMPK-ULK1 S317 pathway and an AKT-mTOR-ULK1 S757 pathway as modules which control ATG S318 phosphorylation and autophagosome formation. The knockdown of PKG reduced cell killing as well as reducing drug-enhanced phosphorylation of ATM, AMPKα, and ATG13. In the absence of PKG, no significant increase in ULK1 S317 phosphorylation was observed. In a Beclin1-dependent fashion, the drug combination reduced the expression of multiple histone deacetylase (HDAC) proteins, including HDAC2 and HDAC3. Molecular knockdown of HDAC2, HDAC3, and especially (HDAC2+HDAC3) significantly reduced the expression of PD-L1 and elevated expression of Class I human major histocompatibility complex. In vivo, (curcumin+sildenafil) enhanced the efficacy of 5-flurouracil against CT26 colorectal tumors. Prior exposure of established CT26 tumors to (curcumin+sildenafil) significantly enhanced the efficacy of a subsequently administered anti-PD-1 antibody. Collectively our data argue that (curcumin+sildenafil) has the potential in several settings to be an efficacious neoadjuvant therapy for colon cancer.

In search of new anticancer drugs: Data for cytotoxic activities of green synthesized silver nanoparticles from ethanolic extracts of fruits and leaves of Annona muricata and 5-Fluorouracil against HeLa, PC3 and PNT1A cell lines

In this article, we present data on the anticancer activities of green synthesized silver nanoparticles (AgNPs) from ethanolic extracts of fruits (AgNPs-F) and leaves (AgNPs-L) of Annona muricata and standard anticancer drug 5-Fluorouracil (5-FU) on two cancer cell lines, i.e. cervical adenocarcinoma (HeLa cells) and prostate adenocarcinoma (PC3 cells) as well as on an immortalized normal prostate cell line, PNT1A. The cytotoxicity on the cells was determined by measuring the absorbance signal of resazurin dye. It has long been known that metabolically active cells change the resazurin from blue (oxidized) to red (reduced) forms, corresponding to the absorbance signals at a wavelength of 570nm (A570) and 600nm (A600) respectively, from which therefore the effects of any treatments on percentage cell viability/death can be elucidated. The raw data values of the treatments against the HeLa, PC3 and PNT1A cells are shown in the different Tables. Examples of how the data can be analyzed have been illustrated using different growth inhibition curves. The data can be used by academics, students, and researchers working on development of anticancer drugs.

Stem extract of Tabebuia chrysantha induces apoptosis by targeting sEGFR in Ehrlich Ascites Carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

The plant Tabebuia chrysantha (Jaq.) Nicholson (Bignoniaceae) is commonly known as "Golden Goddess" in the Southern part of India and "Golden Trumpet Tree " in Central America. Stems of this plant have been traditionally used for antioxidant, anti-inflammatory, antimicrobial and anticancer actions.

AIM OF THE STUDY

To evaluate the antitumor activity of methanol extract of Tabebuia chrysantha stem (METC).

MATERIALS AND METHODS

The in vivo antitumor potential of METC against Ehrlich Ascites Carcinoma (EAC) in Swiss albino mice was assessed by evaluating tumor volume, viable and nonviable tumor cell count, tumor weight, hematological parameters, biochemical parameters, and antioxidant parameters. The in vitro antitumor potential of METC at different concentrations (100, 200, 400, 800, 1000) µg/mL has been evaluated, by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and Trypan blue dilution assay for a period of 3 h treatment. Before that, the crude extract was pre-screened for cytotoxicity property using Brine shrimp lethality bioassay.

RESULTS

Phytoconstituents 2-Hydroxynaphthalene-1,4-dione, β-lapachone and 2-((dimethylamino)methyl)-3-methoxynaphthalene-1,4-dione were isolated from the METC. Their occurrence and structures were determined by HPLC chromatography, UV spectroscopy, and 1D and ²D NMR spectroscopies respectively. The extract showed a direct cytotoxic effect on EAC cells in a dose-dependent manner with IG₅₀ value 463.27 µg/mL in MTT assay and 443.58 µg/mL in trypan blue dilution assay. The METC (300 mg/kg) and 5-FU (30 mg/kg) exhibited significant (p < 0.001) decrease in tumor volume, tumor weight and viable cell count of EAC-treated mice. Also, hematological profile, tissue parameters such as lipid peroxidation, reduced glutathione, superoxide dismutase, and catalase were reverted to the normal levels compared to the EAC control group. The Western blotting analysis demonstrated apoptosis of carcinoma was due to inhibition of soluble epidermal growth factor receptor proteins (sEGFR) expression in the blood.

CONCLUSION

The antitumor potential of the stem extract of T chrysantha was due to naphthaquinones and polyphenol content in the crude extract and so T chrysantha could be a cytotoxic plant to control tumor growth.

The inhibition of thymidine phosphorylase can reverse acquired 5FU-resistance in gastric cancer cells

BACKGROUND

5FU can be converted to its active metabolite fluoro-deoxyuridine monophosphate (FdUMP) through two pathways: the orotate phosphoribosyl transferase-ribonucleotide reductase (OPRT-RR) pathway and the thymidine phosphorylase-thymidine kinase (TP-TK) pathway. We investigated the mechanism underlying 5FU-resistance, focusing on the changes in the 5FU metabolisms.

METHODS

MKN45 and 5FU-resistant MKN45/F2R cells were treated with 5FU or fluoro-deoxyuridine (FdU) in combination with hydroxyurea (HU) or tipiracil (TPI). The amount of FdUMP was determined by the density of the upper band of thymidylate synthase on Western blotting.

RESULTS

The MKN45/F2R cells exhibited 5FU resistance (37.1-fold) and showed decreased OPRT and increased TP levels. In both cells, the FdUMP after treatment with 5FU was decreased when RR was inhibited by HU but not when TP was inhibited by TPI. A metabolome analysis revealed the loss of intracellular deoxyribose 1-phosphate (dR1P) in both cells, indicating that FdUMP was synthesized from 5FU only through the OPRT-RR pathway because of the loss of dR1P. After the knockdown of TK, the FdUMP after treatment with FdU was decreased in MKN45 cells. However, it was not changed in MKN45/F2R cells. Furthermore, TP inhibition caused an increase in FdUMP after treatment with 5FU or FdU and reversed the 5FU resistance in MKN45/F2R cells, indicating that FdUMP was reduced through the TP-TK pathway in MKN45/F2R cells.

CONCLUSIONS

In MKN45/F2R cells, the reduction of FdUMP through the TP-TK pathway caused 5FU resistance, and the inhibition of TP reversed the resistance to 5FU, suggesting that the combination of 5FU and TPI is a promising cancer therapy.

CD13 Inhibition Enhances Cytotoxic Effect of Chemotherapy Agents

Multidrug resistance (MDR) of hepatocellular carcinoma is a serious problem. Although CD13 is a biomarker in human liver cancer stem cells, the relationship between CD13 and MDR remains uncertain. This study uses liver cancer cell model to understand the role of CD13 in enhancing the cytotoxic effect of chemotherapy agents. Cytotoxic agents can induce CD13 expression. CD13 inhibitor, bestatin, enhances the antitumor effect of cytotoxic agents. Meanwhile, CD13-targeting siRNA and neutralizing antibody can enhance the cytotoxic effect of 5-fluorouracil (5FU). CD13 overexpression increases cell survival upon cytotoxic agents treatment, while the knockdown of CD13 causes hypersensitivity of cells to cytotoxic agents treatment. Mechanistically, the inhibition of CD13 leads to the increase of cellular reactive oxygen species (ROS). BC-02 is a novel mutual prodrug (hybrid drug) of bestatin and 5FU. Notably, BC-02 can inhibit cellular activity in both parental and drug-resistant cells, accompanied with significantly increased ROS level. Moreover, the survival time of Kunming mice bearing H22 cells under BC-02 treatment is comparable to the capecitabine treatment at maximum dosage. These data implicate a therapeutic method to reverse MDR by targeting CD13, and indicate that BC-02 is a potent antitumor compound.

Hepatic Leukemia Factor Maintains Quiescence of Hematopoietic Stem Cells and Protects the Stem Cell Pool during Regeneration

The transcription factor hepatic leukemia factor (HLF) is strongly expressed in hematopoietic stem cells (HSCs) and is thought to influence both HSC self-renewal and leukemogenesis. However, the physiological role of HLF in hematopoiesis and HSC function is unclear. Here, we report that mice lacking Hlf are viable with essentially normal hematopoietic parameters, including an intact HSC pool during steady-state hematopoiesis. In contrast, when challenged through transplantation, Hlf-deficient HSCs showed an impaired ability to reconstitute hematopoiesis and became gradually exhausted upon serial transplantation. Transcriptional profiling of Hlf-deficient HSCs revealed changes associated with enhanced cellular activation, and cell-cycle analysis demonstrated a significant reduction of quiescent HSCs. Accordingly, toxic insults targeting dividing cells completely eradicated the HSC pool in Hlf-deficient mice. In summary, our findings point to HLF as a critical regulator of HSC quiescence and as an essential factor for maintaining the HSC pool during regeneration.

Up-regulation of UVRAG by HDAC1 Inhibition Attenuates 5FU-induced Cell Death in HCT116 Colorectal Cancer Cells

The ultraviolent irradiation resistance-associated gene (UVRAG), a component of the Beclin 1/autophagy-related 6 complex, regulates the autophagy initiation step and functions in the DNA-damage response. UVRAG is frequently mutated in various cancer types, and mutations of UVRAG increase sensitivity to chemotherapy by impairing DNA-damage repair. In this study, we addressed the epigenetic regulation of UVRAG in colorectal cancer cells. UVRAG expression was increased in cells treated with histone deacetylase (HDAC) inhibitors, such as valproic acid and suberoylanilide hydroxamic acid. Down-regulation of HDAC1 enhanced UVRAG expression in colorectal cancer cells. In addition, both chemical and genetic inhibition of HDAC1 reduced the activation of caspase-3 and cytotoxicity in 5-fluorouracil (5FU)-treated cancer cells. In contrast, UVRAG overexpression inhibited caspase activation and cell death in 5FU-treated cells. Taken together, our findings suggest that up-regulation of UVRAG by HDAC1 inhibition potentiates DNA-damage-mediated cell death in colorectal cancer cells.

5FU resistance caused by reduced fluoro-deoxyuridine monophosphate and its reversal using deoxyuridine

The mechanism of 5-fluorouracil (5FU) resistance was investigated, focusing on the level of thymidylate synthase (TS) ternary complex formed with fluoro-deoxyuridine monophosphate (FdUMP). MKN45 and 5FU-resistant MKN45/F2R cells were treated with 5FU and fluoro-deoxyuridine (FdU) in combination with deoxyuridine (dU) and thymidine (dT). Subsequently, the levels of ternary complex were determined by western blotting and the cell viability was calculated using an MTT assay. MKN45/F2R cells exhibited 5FU resistance (56.2-fold relative to MKN45 cells), and demonstrated decreased orotate phosphoribosyltransferase (OPRT) and increased TS levels, requiring a higher concentration of 5FU to induce ternary complex formation than MKN45 cells. Following transfection of small interfering RNA against OPRT, MKN45 exhibited increased resistance to 5FU and decreased ternary complex formation subsequent to treatment with 5FU, indicating that decreased OPRT led to increased 5FU resistance. However, MKN45/F2R also exhibited resistance to FdU, which can be converted to FdUMP without OPRT, and there was decreased ternary complex formation after treatment with FdU, indicating that the 5FU-resistant cells had the ability to decrease intracellular FdUMP. The addition of dU and thymidine dT to 5FU promoted the formation of ternary complexes and reversed 5FU resistance in MKN45/F2R cells, although dT inhibited the efficacy of raltitrexed (another TS inhibitor). These results suggested that 5FU-resistant cells had the ability to reduce intracellular FdUMP irrespective of decreased OPRT, which led to resistance to 5FU. This resistance was then inhibited by treatment with dT or dU.

Comparison cisplatin with cisplatin plus 5FU in head and neck cancer patients received postoperative chemoradiotherapy

PURPOSE

To compare the treatment outcomes and toxicity of both cisplatin and cisplatin plus 5FU chemotherapy in head and neck cancer patients who have received surgery, in addition to postoperative chemoradiotherapy.

MATERIALS AND METHODS

From May 1991 to December 2012, a total of 113 head and neck cancer patients who received surgery, along with postoperative chemoradiotherapy were analyzed. The primary sites were oral cavity (86), oropharynx (17), hypopharynx (4), and larynx (6). Thirty-nine patients received cisplatin (P), while 74 patients received cisplatin plus 5FU (PF). The endpoints were overall survival (OS), local failure-free survival (LFFS), and distant metastasis-free survival (DMFS).

RESULTS

The median follow up time was 43months, with a range of 4-222months. The 3-year rates of OS, LFFS, and DMFS were 62.1%, 71.3%, and 82.4%, respectively. The 3-year OS for P and PF were 71.3% and 57.5% (p=0.27). A multivariate analysis revealed that various chemotherapy regimens displayed no statistical difference for OS (Hazard Ratio [HR]=1.81; 95% Confidence Interval [CI]=0.963-3.408; p=0.065), LFFS (HR=0.98; 95% CI=0.458-2.127; p=0.973), and DMFS (HR=1.25; 95% CI=0.463-3.398; p=0.656). Grade 3 and 4 mucositis for P and PF group were 61.5% and 64.9%. A greater than grade 3 dermatitis for P and PF group were 7.7% and 14.9%.

CONCLUSION

Postoperative chemoradiotherapy with cisplatin alone appeared to have higher 3-year OS and lower severe mucositis and dermatitis than cisplatin plus 5FU.

Optimization of chitosan nanoparticles for colon tumors using experimental design methodology

Purpose Colon-specific drug delivery systems (CDDS) can improve the bio-availability of drugs through the oral route. A novel formulation for oral administration using ligand coupled chitosan nanoparticles bearing 5-Flurouracil (5FU) encapsulated in enteric coated pellets has been investigated for CDDS. Method The effect of polymer concentration, drug concentration, stirring time and stirring speed on the encapsulation efficiency, and size of nanoparticles were evaluated. The best (or optimum) formulation was obtained by response surface methodology. Using the experimental data, analysis of variance has been carried out to evolve linear empirical models. Using a new methodology, polynomial models have been evolved and the parametric analysis has been carried out. In order to target nanoparticles to the hyaluronic acid (HA) receptors present on colon tumors, HA coupled nanoparticles were tested for their efficacy in vivo. The HA coupled nanoparticles were encapsulated in pellets and were enteric coated to release the drug in the colon. Results Drug release studies under conditions of mimicking stomach to colon transit have shown that the drug was protected from being released in the physiological environment of the stomach and small intestine. The relatively high local drug concentration with prolonged exposure time provides a potential to enhance anti-tumor efficacy with low systemic toxicity for the treatment of colon cancer. Conclusions Conclusively, HA coupled nanoparticles can be considered as the potential candidate for targeted drug delivery and are anticipated to be promising in the treatment of colorectal cancer.

Development of rectal delivered thermo-reversible gelling film encapsulating a 5-fluorouracil hydroxypropyl-β-cyclodextrin complex

We have developed a novel 5-Fluorouracil (5FU) formulation for rectal application to improve its therapeutic efficiency in colorectal cancer. The results indicated that 5FU formed an inclusion complex with Hydroxypropyl-β-Cyclodextrin (HP-β-CD). The stoichiometry of the complex was 1:1, with apparent stability constant of 100.4M(-1). After investigating physicochemical properties of the 5FU-HP-β-CD complex encapsulated with thermo-reversible gelling film, the optimized formulation P407/P188/HPMC/5FU-HP-β-CD (18.5/2.5/0.2/15%) was selected and evaluated. The result showed that the 5FU-HP-β-CD complex increased the solubility of 5FU, prolonged and enhanced its releasing. As compared to the raw drug, the transport efficiency of the 5FU-HP-β-CD complex itself or entrapped in thermo-reversible gelling film were respectively 7.3- and 6.8-fold increased, and the cellular uptake of 5-FU 4.9- and 5.4-fold elevated. There was no irritation or damage to rectal sites in the 10h treatment period. Therefore, this HP-β-CD based formulation might improve the therapeutic effect of 5FU on colon-rectal cancer.

The influence of p53 status on the cytotoxicity of fluorinated pyrimidine L-nucleosides

Fluorinated nucleoside analogues are a major class of cancer chemotherapy agents, and include the drugs 5-fluorouracil (5FU) and 5-fluoro-2'-deoxyuridine (FdUrd). The aim of this study was to examine the cellular toxicity of two novel fluorinated pyrimidine L-nucleosides that are enantiomers of D-nucleosides and may be able to increase selectivity for cancer cells as a result of their unnatural L-configuration. Two fluorinated pyrimidine L-nucleosides were examined in this study, L110 ([β-L, β-D]-5-fluoro-2'-deoxyuridine) and L117 (β-L-deoxyuridine:β-D-5'-fluoro-2'-deoxyuridine). The cytotoxicity of these L-nucleoside was determined in primary mouse fibroblasts and was compared with 5FU and FdUrd. In addition, the influence of p53 status on cytotoxicity was investigated. These cytotoxicity assays were performed on a matched set of primary mouse fibroblasts that were either wild type or null for the p53 tumour suppressor gene. It was found that cells lacking functional p53 were over 7500 times more sensitive to the drugs L110, L117 and FdUrd than cells containing wild type p53.

Pretreatment With L-Citrulline Positively Affects the Mucosal Architecture and Permeability of the Small Intestine in a Murine Mucositis Model

BACKGROUND

Mucositis is a common complication in patients undergoing radiotherapy and chemotherapy. It is associated with pain, poor quality of life, and malnutrition, leading to an increased number of hospital admissions and prolonged hospitalization. The use of immunonutrients may be an alternative treatment option, which may help to improve patient outcome.

OBJECTIVE

Here we assessed the impact of L-citrulline (CIT) on a murine model of 5-fluorouracil (5FU)-induced mucositis.

METHODS

Swiss male mice were randomized into 4 groups: control, CIT, 5FU, and 5FU+CIT. Mice were fed with commercial chow and supplemented with an oral solution of alanine (control and 5FU groups) or CIT (CIT and 5FU+CIT groups). On the seventh day, mice received intraperitoneal phosphate-buffered saline or 5FU (200 mg/kg, single dose) to induce mucositis. On the 10th day, mice were euthanized, and the blood and small intestines were harvested. Body weight, morphology, histopathology score (hematoxylin and eosin) of the small intestine (from 0-12), myeloperoxidase activity, oxidative stress level, and intestinal permeability were assessed.

RESULTS

We observed significant weight loss after the administration of 5FU in both treated and control animals. CIT administration contributed to a partial recovery of the mucosal architecture as well as an intermediate reduction of the histopathologic score, and functional intestinal permeability was partially rescued.

CONCLUSIONS

CIT administration attenuated 5FU-mediated damage to the mucosal architecture of the small intestine, decreasing the size of the injured areas and promoting decreased intestinal permeability.

Inhibition of p53 increases chemosensitivity to 5-FU in nutrient-deprived hepatocarcinoma cells by suppressing autophagy

Activation of p53 can induce apoptosis, cell cycle arrest, and cell senescence, although some evidence has suggested that p53 could promote cell survival. However, whether p53 plays a positive role in cancer cell survival to chemotherapy remains unknown. In this study, we show that inhibition of p53 enhanced apoptosis and increased chemosensitivity to 5-fluorouracil (5-FU) in nutrient-deprived hepatocarcinoma cells (HCC). Meanwhile, nutrient-deprivation-induced autophagy was inhibited by pifithrin-α or small interfering RNA targeting p53. The expression of p53 was not increased when HCC were incubated under nutrient-deprived conditions. This indicates that the basal level of p53 is important to autophagy activation in nutrient-deprived HCC cells. Furthermore, combining p53 inhibition and nutrient deprivation or 5-FU treatment resulted in a marked increase in reactive oxygen species generation and mitochondrial damage. Antioxidants reduced nutrient deprivation or 5-FU-induced cell death of HCC after p53 inhibition. Our results suggest that p53 contributes to cell survival and chemoresistance in HCC under nutrient-deprived conditions by modulating autophagy activation.

Curcumin and 5-fluorouracil-loaded, folate- and transferrin-decorated polymeric magnetic nanoformulation: a synergistic cancer therapeutic approach, accelerated by magnetic hyperthermia

The efficient targeting and therapeutic efficacy of a combination of drugs (curcumin and 5-Fluorouracil [5FU]) and magnetic nanoparticles encapsulated poly(D,L-lactic-co-glycolic acid) nanoparticles, functionalized with two cancer-specific ligands are discussed in our work. This multifunctional, highly specific nanoconjugate resulted in the superior uptake of nanoparticles by cancer cells. Upon magnetic hyperthermia, we could harness the advantages of incorporating magnetic nanoparticles that synergistically acted with the drugs to destroy cancer cells within a very short period of time. The remarkable multimodal efficacy attained by this therapeutic nanoformulation offers the potential for targeting, imaging, and treatment of cancer within a short period of time (120 minutes) by initiating early and late apoptosis.

Antimetabolite Treatment for Pancreatic Cancer

Pancreatic cancer is a deadly and aggressive disease. Less than 1% of diagnosed patients survive 5 years with an average survival time of only 4–8 months. The only option for metastatic pancreatic cancer is chemotherapy where only the antimetabolites gemcitabine and 5-fluorouracil are used clinically. Unfortunately, efforts to improve chemotherapy regimens by combining, 5-fluorouracil or gemcitabine with other drugs, such as cisplatin or oxaliplatin, have not increased cell killing or improved patient survival. The novel antimetabolite zebularine shows promise, inducing apoptosis and arresting cellular growth in various pancreatic cancer cell lines. However, resistance to these antimetabolites remains a problem highlighting the need to discover and develop new antimetabolites that will improve a patient’s overall survival.

Drug interactions with solid tumour-targeted therapies

Drug interactions are an on-going concern in the treatment of cancer, especially when targeted therapies, such as tyrosine kinase inhibitors (TKI) or mammalian target of rapamycin (mTOR) inhibitors, are being used. The emergence of elderly patients and/or patients with both cancer and other chronic co-morbidities leads to polypharmacy. Therefore, the risk of drug-drug interactions (DDI) becomes a clinically relevant issue, all the more so as TKIs and mTOR inhibitors are essentially metabolised by cytochrome P450 enzymes. These DDIs can result in variability in anticancer drug exposure, thus favouring the selection of resistant cellular clones or the occurrence of toxicity. This review provides a comprehensive overview of DDIs that involve targeted therapies approved by the FDA for the treatment of solid tumours for more than 3 years (sorafenib, sunitinib, erlotinib, gefitinib, imatinib, lapatinib, everolimus, temsirolimus) and medicinal herb or drugs. This review also provides some guidelines to help oncologists and pharmacists in their clinical practice.