Schisandrin A can promote the anti-tumor effect of 5-Fu by reversing the immunosuppressive state of the body in rat.

In this study, based on Walker 256 in vitro experiments, CCK-8 assay, clone formation assay, wound healing assay, and flow cytometry were used to detect cell apoptosis and cell cycle. It was found that schisandrin may have significant anti-tumor effects in vitro by inhibiting TGF-ß/Smad signaling pathway. In addition, in vivo experiments, immunohistochemistry was used to observe the expression of HIF-1α, VEGF and VEGFR-2 in tumor tissues. It was found that schisandrin could significantly improve the immunosuppression induced by 5-Fu and enhance the antitumor effect of 5-Fu. The mechanism may be related to the inhibition of Wnt-1/ß-catenin signaling pathway.

The combination of SHP099 inhibits the malignant biological behavior of L-OHP/5-FU-resistant colorectal cancer cells by regulating energy metabolism reprogramming.

BACKGROUND AND OBJECTIVE: Colorectal cancer (CRC) is one of the most common malignancies in China. At present, there is a problem that the CRC treatment drugs SHP099, L-OHP and 5-FU are insensitive to tumor cells. Combination medication is an important means to solve the insensitivity of medication alone. The purpose of this project was to explore the effect and molecular mechanism of SHP099 combination on the malignant biological behavior of L-OHP/5-FU resistant strains of CRC. METHODS: HT29 and SW480 cells were cultured in media supplemented with L-OHP or 5-FU to establish drug-resistant strains. HT29 and SW480 drug-resistant cells were subcutaneously injected into the ventral nerves of nude mice at a dose of 5 × 106 to establish CRC drug-resistant animal models. CCK-8, Western blot, flow cytometry, Transwell and kit detection were used to detect the regulatory mechanism of energy metabolism reprogramming in drug-resistant CRC cells. RESULTS: Compared with nonresistant strains, L-OHP/5-FU-resistant strains exhibited greater metabolic reprogramming. Functionally, SHP099 can restrain the metabolic reprogramming of L-OHP/5-FU-resistant strains and subsequently restrain the proliferation, colony formation, migration and spheroid formation of L-OHP/5-FU-resistant strains. Downstream mechanistic studies have shown that SHP099 interferes with the metabolic reprogramming of L-OHP/5-FU drug-resistant strains by suppressing the PI3K/AKT pathway, thereby restraining the malignant biological behavior of L-OHP/5-FU drug-resistant strains and alleviating CRC. CONCLUSION: The combination of SHP099 can restrain the malignant biological behavior of L-OHP/5-FU-resistant CRC cells and alleviate the progression of CRC by interfering with the reprogramming of energy metabolism. This study explored the effect of SHP099 combination on dual-resistant CRC cells for the first time, and provided a new therapeutic idea for solving the problem of SHP099 insensitivity to CRC cells.

The function and mechanism of circRNAs in 5-fluorouracil resistance in tumors: Biological mechanisms and future potential.

5-Fluorouracil (5-FU) is a well-known chemotherapy drug extensively used in the treatment of breast cancer. It works by inhibiting cancer cell proliferation and inducing cell death through direct incorporation into DNA and RNA via thymidylate synthase (TS). Circular RNAs (circRNAs), a novel family of endogenous non-coding RNAs (ncRNAs) with limited protein-coding potential, contribute to 5-FU resistance. Their identification and targeting are crucial for enhancing chemosensitivity. CircRNAs can regulate tumor formation and invasion by adhering to microRNAs (miRNAs) and interacting with RNA-binding proteins, regulating transcription and translation. MiRNAs can influence enzymes responsible for 5-FU metabolism in cancer cells, affecting their sensitivity or resistance to the drug. In the context of 5-FU resistance, circRNAs can target miRNAs and regulate biological processes such as cell proliferation, cell death, glucose metabolism, hypoxia, epithelial-to-mesenchymal transition (EMT), and drug efflux. This review focuses on the function of circRNAs in 5-FU resistance, discussing the underlying molecular pathways and biological mechanisms. It also presents recent circRNA/miRNA-targeted cancer therapeutic strategies for future clinical application.

PEG-modified Fe2O3 coated agarose hydrogel: A synthesized nanocomposite for regulated 5-fluorouracil delivery.

An innovative pH-responsive nanocomposite, comprising agarose (AGA) modified with polyethylene glycol (PEG) hydrogel and coated with ferric oxide (Fe2O3), has been formulated to facilitate the precise administration of 5-fluorouracil (5-Fu) to breast cancer cells. By utilizing a double emulsion technique, the size of the nanocomposites was significantly reduced through the application of almond oil; the inclusion of span 80 further improved their uniformity. The physiochemical properties of the nanocomposite were thoroughly examined by Fourier Transformed Infrared (FT-IR), X-ray diffraction (XRD), Field Emission-Scanning Electron Microscope (FE-SEM), Vibrating Sample Magnetometer (VSM), dynamic light scattering (DLS), and zeta potential tests. The verification of the uniform particle distribution was achieved by employing FE-SEM and VSM analyses. The average diameter of the particles was 223 nm, and their zeta potential was -47.6 mV. In addition, the nanocomposite exhibited a regulated release of 5-Fu at pH 5.4 and pH 7.4, as indicated by an in vitro drug release profile. PEG-AGA- Fe2O3@5-Fu exhibited biocompatibility, as indicated by the lack of deleterious effects observed in tumor cells. This revolutionary nanocomposite demonstrates exceptional promise as a vehicle for breast cancer treatment, underscoring its significance as a significant progression in the ongoing pursuit of novel nanotechnologies for cancer therapy.

Binding and displacement study of gentamicin, 5-fluorouracil, oxytetracycline and rolitetracycline with (BSA: Drug2) complex using spectroscopic and calorimetric techniques: Biophysical approach.

Understanding of energetics of interactions between drug and protein is essential in pharmacokinetics and pharmacodynamics study. The binding affinity (K) helps in investigating how tightly or loosely drug is bound to protein. The binding, displacement, conformational change and stability study of drugs- gentamicin (GM), 5-fluorouracil (5FU), oxytetracycline (OTC) and rolitetracycline (RTC) with bovine serum albumin (BSA) has been carried out in presence of each other drug by fluorescence, UV-visible spectroscopy, molecular docking, circular dichroism techniques and thermal denaturation method. The site marker study and docking methods have confirmed that 5FU and GM are able to bind at site 1 and OTC and RTC at site II of BSA. The order of their binding affinities with BSA for the binary system were as GM <5FU < OTC < RTC with the order of 102 < 103 < 105 < 105-6 M-1. The displacement study has shown that higher affinity drug decreases the equilibrium constant of another drug already in bound state with BSA if both these drugs are having the same binding site. Therefore 5FU, GM (binding site 1) drugs were not able to displace OTC and RTC (binding site 2) and vice-versa as they are binding at two different sites. The binding constant values were found to be decreasing with increasing temperature for all the systems involved which suggests static or mixed type of quenching, however can only confirmed with the help of TCSPC technique. The ΔG0 (binding energy) obtained from docking method were in accordance with the ITC method. From molecular docking we have determined the amino acid residues involved in binding process for binary and ternary systems by considering first rank minimum binding energy confirmation. From CD it has been observed that RTC causes most conformational change in secondary and tertiary structure of BSA due to the presence of pyrrole ring. OTC-RTC with higher affinity showed highest melting temperature Tm values while low affinity drugs in (5FU-GM) combination showed lowest Tm value. 5FU showed large endothermic denaturation enthalpy ΔHd0 due to the presence of highly electronegative fluorine atom in the pyridine analogue.

Pediococcus pentosaceus PP34 Ameliorates 5-Fluorouracil-Induced Intestinal Mucositis via Inhibiting Oxidative Stress and Restoring the Gut Microbiota.

Chemotherapy-induced intestinal mucositis based on 5-fluorouracil (5-FU) slows down the progress of cancer treatment and causes significant suffering to patients. Pediococcus pentosaceus (P. pentosaceus), as a type of LAB, has a range of probiotic properties, including antioxidant, immune benefits, and cholesterol-lowering effects, which are attracting increasing attention. However, studies on the protective effect of P. pentosaceus against chemotherapeutic-induced intestinal mucositis caused by 5-FU remain unclear. Therefore, this study aimed to investigate the potential relieving effects of P. pentosaceus PP34 on 5-FU-induced intestinal mucositis and its mechanism. In the present study, a P. pentosaceus PP34 solution (2 × 109 CFU/mL) was administered daily by gavage followed by intraperitoneal injection of 5-FU to model intestinal mucositis. The body weight, serum biochemical indices, jejunal pathological organization, and expression levels of inflammatory cytokines in the jejunum were examined. The results indicated that the mice induced with 5-FU developed typical intestinal mucositis symptoms and histopathological changes with intense inflammatory and oxidative responses. Moreover, the gut microbiota was disturbed, while PP34 effectively decreased the oxidative reactions and the expression levels of inflammatory mediators and regulated the gut microbiota in 5-FU-exposed mice. Taken together, the study indicated that P. pentosaceus PP34 ameliorates 5-Fluorouracil-induced intestinal mucositis via inhibiting oxidative stress and restoring the gut microbiota.

Safety and adherence to self-administered intravaginal 5-fluorouracil cream following cervical intraepithelial neoplasia (CIN) 2/3 treatment among HIV-positive women in Kenya: A phase 1 clinical trial.

Objective: To determine the safety, tolerance, and adherence to self-administered intravaginal 5% fluorouracil (5FU) cream as adjuvant therapy following cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3) treatment among women living with HIV (WLWH) in Kenya. Methods: A Phase I Pilot trial was performed among 12 WLWH in Kenya, aged 18-49 years between March 2023-February 2024 (ClinicalTrial.gov NCT05362955). Participants self-administered 2g of 5FU intravaginally every other week for eight applications. Safety was assessed using a standardized grading scale, and adherence was evaluated using self-report, inspection of used applicators, and weighing of the study drug. Results: The mean age and CD4 count were 43.9 years and 781 cells/mm3, respectively. Seven (58%) had an 8th-grade education or less. All 12 reported at least one grade I adverse event (AE), 1 (8%) reported a grade 2 AE, no grade 3 or 4 AEs were reported. Increased vaginal discharge (n=9, 75%) and irritation (n=5, 42%), with a mean duration of 3.2 and 2.8 days, respectively, were the most commonly reported AEs. Provider-observed AEs included grade 1 cervical erythema and superficial abrasions. All participants tolerated all eight 5FU doses, and 96% adherence was demonstrated. Conclusion: Self-administered 5FU following CIN2/3 treatment among WLWH in Kisumu, Kenya, was safe, tolerable, and associated with high adherence. Randomized trials are needed to investigate whether adjuvant 5FU can improve treatment outcomes or serve as primary cervical precancer treatment in sub-Saharan Africa. A self-administered therapy may be transformative in increasing access to treatment and, hence, secondary prevention of cervical cancer.

Rapid detection of the irinotecan-related UGT1A1 & 5-fluorouracil related DPYD polymorphism by asymmetric polymerase chain reaction melting curve analysis.

BACKGROUND: Determination of DPYD and UGT1A1 polymorphisms prior to 5-fluorouracil and irinotecan therapy is crucial for avoiding severe adverse drug effects. Hence, there is a pressing need for accurate and reliable genotyping methods for the most common DPYD and UGT1A1 polymorphisms. In this study, we introduce a novel polymerase chain reaction (PCR) melting curve analysis method for discriminating DPYD c.1236G > A, c.1679 T > G, c.2846A > T, IVS14 + 1G > A and UGT1A1*1, *28, *6 (G71R) genotypes. METHODS: Following protocol optimization, this technique was employed to genotype 28 patients, recruited between March 2023 and October 2023, at the First Affiliated Hospital of Xiamen University. These patients included 20 with UGT1A1 *1/*1, 8 with UGT1A1 *1/*28, 4 with UGT1A1 *28/*28, 22 with UGT1A1*6 G/G, 6 with UGT1A1*6 G/A, 4 with UGT1A1*6 A/A, 27 with DPYD(c.1236) G/G, 3 with DPYD(c.1236) G/A, 2 with DPYD(c.1236) A/A, 27 with DPYD(c.1679) T/T, 2 with DPYD(c.1679) T/G, 3 with DPYD(c.1679) G/G, 28 with DPYD(c.2846A/T) A/A, 2 with DPYD(c.2846A/T) A/T, 2 with DPYD(c.2846A/T) T/T, 28 with DPYD(c.IVS14 + 1) G/G, 2 with DPYD(c.IVS14 + 1) G/G, and 2 with DPYD(c.IVS14 + 1) G/G, as well as 3 plasmid standards. Method accuracy was assessed by comparing results with those from Sanger sequencing or Multiplex quantitative PCR(qPCR). Intra- and inter-run precision of melting temperatures (Tms) were calculated to evaluate reliability, and sensitivity was assessed through limit of detection examination. RESULTS: The new method accurately identified all genotypes and exhibited higher accuracy than Multiplex qPCR. Intra- and inter-run coefficients of variation for Tms were both ≤1.97 %, with standard deviations ≤0.95 °C. The limit of detection was 0.09 ng/µL of input genomic DNA. CONCLUSION: Our developed PCR melting curve analysis offers accurate, reliable, rapid, simple, and cost-effective detection of DPYD and UGT1A1 polymorphisms. Its application can be easily extended to clinical laboratories equipped with a fluorescent PCR platform.

Selumetinib overcomes ITGA2-induced 5-fluorouracil resistance in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most malignant tumor in the world. 5-fluorouracil (5­FU) -based chemotherapy is the first-line chemotherapy scheme for CRC, whereas acquired drug resistance poses a huge obstacle to curing CRC patients and the mechanism is still obscure. Therefore, identification of genes associated with 5­FU chemotherapy and seeking second-line treatment are necessary means to improve survival and prognosis of patients with CRC. METHODS: The Cancer Therapeutics Response Portal (CTRP) database and Genomics of Drug Sensitivity in Cancer (GDSC) database were used to identify CRC-related genes and potential second-line therapies for 5-FU-resistant CRC. The single-cell RNA sequencing data for CRC tissues were obtained from a GEO dataset. The relationship between ITGA2 and 5-FU-resistant was investigated in vitro and in vivo models. RESULTS: ACOX1 and ITGA2 were identified as risk biomarkers associated with 5-FU-resistance. We developed a risk signature, consisting of ACOX1 and ITGA2, that was able to distinguish well between 5-FU-resistance and 5-FU-sensitive. The single-cell sequencing data showed that ITGA2 was mainly enriched in malignant cells. ITGA2 was negatively correlated with IC50 values of most small molecule inhibitors, of which selumetinib had the highest negative correlation. Finally, knocking down ITGA2 can make 5-FU-resistant CRC cells sensitive to 5-FU and combining with selumetinib can improve the therapeutic effect of 5-FU resistant cells. CONCLUSION: In summary, our findings demonstrated the critical role of ITGA2 in enhancing chemotherapy resistance in CRC cells and suggested that selumetinib can restore the sensitivity of chemotherapy-resistant CRC cells to 5-FU by inhibiting ITGA2 expression.

Predicting cardiovascular events with fluoropyrimidine chemotherapy using a standard cardiovascular risk calculator.

AIMS: Fluoropyrimidine chemotherapy is important for treatment of many solid tumours but is associated with cardiotoxicity. The relationship of fluoropyrimidine-associated cardiotoxicity (FAC) with conventional cardiovascular (CV) risk factors is poorly understood, and standard cardiovascular risk scores are not validated in this context. METHODS AND RESULTS: Single-centre retrospective study of patients treated with fluoropyrimidine chemotherapy using electronic health records for cardiovascular risk factors (and calculation of QRISK3 score), cancer treatment, and clinical outcomes. FAC was defined by cardiovascular events during or within 3 months of fluoropyrimidine treatment, and Cox regression was used to assess associations of CV risk and cancer treatment with FAC. One thousand eight hundred ninety-eight patients were included (45% male; median age 64 years), with median follow up 24.5 (11.5-48.3 months); 52.7% of patients were at moderate or high baseline CV risk (QRISK3 score >10%) Cardiovascular events occurred in 3.1% (59/1898)-most commonly angina (64.4%, 38/59) and atrial fibrillation (13.6%, 8/59), with 39% events during cycle one of treatment. In univariable analysis, QRISK3 score >20% was significantly associated with incident FAC (HR 2.25, 95% CI 1.11-4.93, P = 0.03). On multivariable analysis, beta-blocker use (HR 1.04, 95% CI 1.00-1.08, P = 0.04) and higher BMI (HR 2.33, 95% CI 1.04-5.19, P = 0.04) were independently associated with incident CV events. Thirty-two of the 59 patients with FAC were subsequently rechallenged with fluoropyrimidine chemotherapy, with repeat CV events in 6% (2/32). Incident FAC did not affect overall survival (P = 0.50). CONCLUSIONS: High BMI and use of beta-blockers are associated with risk of CV events during fluoropyrimidine chemotherapy. QRISK3 score may also play a role in identifying patients at high risk of CV events during fluoropyrimidine chemotherapy. Re-challenge with further fluoropyrimidine chemotherapy can be considered in patients following CV events during prior treatment.

A Comprehensive Review of Non-Surgical Treatments for Hypertrophic and Keloid Scars in Skin of Color.

Hypertrophic and keloid scars are fibroproliferative growths resulting from aberrant wound healing. Individuals with Fitzpatrick skin types (FSTs) IV-VI are particularly predisposed to hypertrophic and keloid scarring, yet specific guidelines for these populations are still lacking within the literature. Therefore, this comprehensive review provides a list of various treatments and considerations for hypertrophic and keloid scarring in patients with skin of color. We constructed a comprehensive PubMed search term and performed quadruple-blinded screening on all resulting studies to achieve this objective. Our findings demonstrate 1) the lack of efficacious treatments for raised scars within this population and 2) the need to empirically investigate individualized and multimodal therapeutic options for those with skin of color.

An Atypical Case of Severe Toxicity, Anterior Chamber Inflammation, and Transient Subretinal Fluid Formation Induced by the Subconjunctival Injection of 5-FU.

PURPOSE: To report an atypical presentation of severe toxicity, anterior chamber (AC) inflammation, and transient parafoveal formation of subretinal fluid induced by the subconjunctival injection of 5-fluorouracil (5-FU). METHODS: Case presentation. RESULTS: Seven weeks after trabeculectomy, a 40-year-old white male had a subconjunctival injection of 5-FU. Within minutes after the injection, the lens turned grey and then total white. Initially, AC was clear, and 20 min later, a severe AC reaction was detected. The patient was prescribed hourly dexamethasone eye drops and tropicamide eye drops twice daily. Two days post-injection, vision improved, AC reaction was minimal, and there was whitish fibrinous material on the anterior surface of the lens, extending up to the pupillary margin. Minimal posterior synechiae were observed, and upon dilation, the remainder of the anterior surface of the lens appeared completely clear, indicating that only the portion of the lens not covered by the iris exhibited fibrinous material and deposits. One week post-injection, vision worsened due to severe corneal toxicity. The dimensions of the whitish fibrinous material on the anterior lens capsule decreased, and macular scans revealed parafoveal subretinal fluid. Two weeks later, vision significantly improved, and the dimensions of the whitish fibrinous material on the anterior lens capsule were further decreased. The subretinal fluid had completely resolved. CONCLUSION: We describe a rare case of severe toxicity, AC inflammation, and transient parafoveal subretinal fluid formation caused by the 5-FU. This was treated with topical steroid treatment, and eventually some level of lens opacification persisted despite significant clearance of the AC inflammation.

Short-term versus long-term metronomic adjuvant chemotherapy in locally advanced nasopharyngeal carcinoma: A propensity score-matched real-world study.

BACKGROUND: This retrospective study aimed to determine the optimal metronomic chemotherapy duration (MTCD) as adjuvant therapy for patients with locally advanced nasopharyngeal carcinoma (LANPC). METHODS: This study involved LANPC patients treated with metronomic chemotherapy (MTC) using a 5-FU prodrug (S1, capecitabine, or tegafur) from May 2013 to September 2020. The optimal MTCD threshold was established using X-tile Bioinformatics software. The overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) were compared between short-term and long-term groups using propensity score matching (PSM). RESULTS: A total of 546 patients were analyzed. MTCD was an independent prognostic factor for OS, PFS, and DMFS (all P < 0.05). Patients were categorized into long-term (>3 months) and short-term (≤3 months) MTCD groups. After a median follow-up of 48 months, significant differences were observed in 4-year OS (97.0 % vs. 87.1 %; P < 0.01), PFS (84.6 % vs. 70.9 %; P < 0.01), DMFS (87.3 % vs. 78.8 %; P < 0.01), and LRRFS (95.3 % vs. 87.4 %; P < 0.01) between the long-term and short-term groups. In the PSM-matched cohort of 196 patients per group, the long-term group demonstrated superior 4-year OS and LRRFS (97.3 % vs. 87.1 %, P < 0.01; 95.2 % vs. 90.0 %, P < 0.05). No significant differences in acute toxicities were observed between the groups (P > 0.05). CONCLUSION: Extended MTC with a 5-FU prodrug (>3 months) may benefit NPC patients. Further prospective studies are needed to validate these findings.

Assessing outcomes of topical 5-fluorouracil as primary and adjuvant therapy for squamous cell carcinoma in-situ.

Cutaneous squamous cell carcinoma in-situ (SCCis) is an intraepithelial tumor with a good prognosis. Standard treatment includes both surgical and non-surgical interventions. We determined the clearance rate for SCCis and residual SCCis identified on frozen section during Mohs micrographic surgery (MMS) after treatment with topical fluorouracil 5% cream (5-FU). All MMS cases were initiated for biopsy-proven invasive squamous cell carcinoma (SCC). A retrospective chart review was conducted from January 2017-February 2024 at Columbia University Irving Medical Center (CUIMC) to identify patients with SCCis who were treated with topical 5-FU as primary therapy or adjuvant therapy (AT) for residual SCCis post-MMS for invasive SCC. 41 patients were included (80% males, 70.1 ± 11.8 years). The average follow-up time for the primary therapy group was 25.4 ± 12.8 months, and for the post-MMS AT group 22.5 ± 11.1 months. In the group treated with topical 5-FU as primary therapy (n = 28), 27 patients (96.43%, 95% confidence interval: 81.65-99.91%) achieved complete clearance. One patient had recurrence at 8 months post-treatment. Of the patients in the post-MMS adjuvant treatment group (n = 13), 12 (92.3% clearance, 95% confidence interval 63.97-99.81%) achieved complete clearance. One patient had recurrence at 8 months post-treatment. This study found that topical 5-FU cream is effective as both primary therapy for SCCis and as adjuvant therapy for residual SCCis following MMS of invasive SCC.

Molecular mechanism of MLCK1 inducing 5-Fu resistance in colorectal cancer cells through activation of TNFR2/NF-κB pathway.

BACKGROUND AND AIMS: Chemotherapy resistance in colorectal cancer have been faced with significant challenges in recent years. Particular interest is directed to tumor microenvironment function. Recent work has, identified a small molecule named Divertin that prevents myosin light chain kinase 1(MLCK1) recruitment to the perijunctional actomyosin ring(PAMR), restores barrier function after tumor necrosis factor(TNF)-induced barrier loss and prevents disease progression in experimental inflammatory bowel disease. Studies have shown that MLCK is a potential target for affecting intestinal barrier function, as well as for tumor therapy. However, the relative contributions of MLCK expression and chemotherapy resistance in colorectal cancers have not been defined. METHODS: Statistical analysis of MYLK gene expression differences in colorectal cancer patients and normal population and prognosis results from The Cancer Genome Atlas(TCGA) data. Cell activity was detected by Cell counting Kit-8. Cell proliferation was detected by monoclonal plate. The apoptosis was detected by flow cytometry and western blot. Determine the role of MLCK1 in inducing 5-Fluorouracil(5-Fu) resistance in colorectal cancer cells was detected by overexpression of MLCK1 and knock-down expression of MLCK1. RESULTS: MLCK1 is expressed at different levels in different colorectal cancer cells, high MLCK1 expressing cell lines are less sensitive to 5-Fu, and low MLCK1 expressing cell lines are more sensitive to 5-Fu. MLCK1 high expression enhances resistance to 5-Fu in colorectal cancer cells and the sensitivity to 5-Fu was increased after knocking down the expression of MLCK1, that might be closely correlated to TNFR2/NF-κB pathway. CONCLUSIONS: MLCK1 high expression can enhance resistance to 5-Fu in colorectal cancer cells and the sensitivity to 5-Fu was increased after knocking down the expression of MLCK1, that might be closely correlated to TNFR2/NF-κB pathway, which will provide a new method for the treatment of colorectal cancer patients who are resistant to 5-Fu chemotherapy.

5-Fluorouracil-induced acute leukoencephalopathy: Case report and literature review.

Toxic leukoencephalopathy (TL) refers to damage to the brain white matter following exposure to toxic agents. Multiple agents are incriminated in this condition, including chemotherapy drugs. 5-Fluorouracil, widely used in oncology, is responsible for neurotoxicity in less than 5% of cases. We report the case of a 54-year-old male patient who presented with neurological symptoms following 5-FU-based chemotherapy for gastric adenocarcinoma, and whose MRI scan revealed signs suggestive of toxic leukoencephalopathy. We also report on the evolution of the abnormalities described on his MRI after 1 year.

Schizandrin A enhances the sensitivity of gastric cancer cells to 5-FU by promoting ferroptosis.

Schizandrin A (Sch A) exert anticancer and multidrug resistance-reversing effects in a variety of tumors, but its effect on 5-fluorouracil (5-Fu) in gastric cancer (GC) cells remains unclear. The aim of the present study was to examine the resistance-reversing effect of Schizandrin A and assess its mechanisms in 5-Fu-resistant GC cells.5-Fu-sensitive GC cells were treated with 5-Fu and 5-Fu-resistant GC cells AGS/5-Fu and SGC7901/5-Fu were were established. These cells were stimulated with Schizandrin A alone or co-treated with 5-Fu and their effect on tumor cell growth, proliferation, migration, invasion and ferroptosis-related metabolism were investigated both in vitro and in vivo. A number of additional experiments were conducted in an attempt to elucidate the molecular mechanism of increased ferroptosis. The results of our study suggest that Schizandrin A in combination with 5-Fu might be useful in treating GC by reverse drug resistance. It was shown that Schizandrin A coadministration suppressed metastasis and chemotherapy resistance in 5-Fu-resistant GC cells through facilitating the onset of ferroptosis, which is an iron-dependent form of cell death, which was further demonstrated in a xenograft nude mouse model. Mechanistically, Schizandrin A co-administration synergistically increased the expression of transferin receptor, thus iron accumulates within cells, leading to lipid peroxidation, which ultimately results in 5-Fu-resistant GC cells death. The results of this study have provided a novel strategy for increasing GC chemosensitivity, indicating Schizandrin A as a novel ferroptosis regulator. Mechanistically, ferroptosis is induced by Schizandrin A coadministration via increasing transferrin receptor expression.

Intelligent nanovesicle for remodeling tumor microenvironment and circulating tumor chemoimmunotherapy amplification.

Imperceptible examination and unideal treatment effect are still intractable difficulties for the clinical treatment of pancreatic ductal adenocarcinoma (PDAC). At present, despite 5-fluorouracil (5-FU), as a clinical first-line FOLFIRINOX chemo-drug, has achieved significant therapeutic effects. Nevertheless, these unavoidable factors such as low solubility, lack of biological specificity and easy to induce immunosuppressive surroundings formation, severely limit their treatment in PDAC. As an important source of energy for many tumor cells, tryptophan (Trp), is easily degraded to kynurenine (Kyn) by indolamine 2,3- dioxygenase 1 (IDO1), which activates the axis of Kyn-AHR to form special suppressive immune microenvironment that promotes tumor growth and metastasis. However, our research findings that 5-FU can induce effectively immunogenic cell death (ICD) to further treat tumor by activating immune systems, while the secretion of interferon-γ (IFN-γ) re-induce the Kyn-AHR axis activation, leading to poor treatment efficiency. Therefore, a metal matrix protease-2 (MMP-2) and endogenous GSH dual-responsive liposomal-based nanovesicle, co-loading with 5-FU (anti-cancer drug) and NLG919 (IDO1 inhibitor), was constructed (named as ENP919@5-FU). The multifunctional ENP919@5-FU can effectively reshape the tumor immunosuppression microenvironment to enhance the effect of chemoimmunotherapy, thereby effectively inhibiting cancer growth. Mechanistically, PDAC with high expression of MMP-2 will propel the as-prepared nanovesicle to dwell in tumor region via shedding PEG on the nanovesicle surface, effectively enhancing tumor uptake. Subsequently, the S-S bond containing nanovesicle was cut via high endogenous GSH, leading to the continued release of 5-FU and NLG919, thereby enabling circulating chemoimmunotherapy to effectively cause tumor ablation. Moreover, the combination of ENP919@5-FU and PD-L1 antibody (αPD-L1) showed a synergistic anti-tumor effect on the PDAC model with abdominal cavity metastasis. Collectively, ENP919@5-FU nanovesicle, as a PDAC treatment strategy, showed excellent antitumor efficacy by remodeling tumor microenvironment to circulate tumor chemoimmunotherapy amplification, which has promising potential in a precision medicine approach.

Wortmannin Inhibits Cell Growth and Induces Apoptosis in Colorectal Cancer Cells by Suppressing the PI3K/AKT Pathway.

BACKGROUND: Colorectal cancer (CRC) remains a significant contributor to mortality, often exacerbated by metastasis and chemoresistance. Novel therapeutic strategies are imperative to enhance current treatments. The dysregulation of the PI3K/Akt signaling pathway is implicated in CRC progression. This study investigates the therapeutic potential of Wortmannin, combined with 5-fluorouracil (5-FU), to target the PI3K/Akt pathway in CRC. METHODS: Anti-migratory and antiproliferative effects were assessed through wound healing and MTT assays. Apoptosis and cell cycle alterations were evaluated using Annexin V/Propidium Iodide Apoptosis Assay. Wortmannin's impact on the oxidant/antioxidant equilibrium was examined via ROS, SOD, CAT, MDA, and T-SH levels. Downstream target genes of the PI3K/AKT pathway were analyzed at mRNA and protein levels using RTPCR and western blot, respectively. RESULTS: Wortmannin demonstrated a significant inhibitory effect on cell proliferation, modulating survivin, cyclinD1, PI3K, and p-Akt. The PI3K inhibitor attenuated migratory activity, inducing E-cadherin expression. Combined Wortmannin with 5-FU induced apoptosis, increasing cells in sub-G1 via elevated ROS levels. CONCLUSION: This study underscores Wortmannin's potential in inhibiting CRC cell growth and migration through PI3K/Akt pathway modulation. It also highlights its candidacy for further investigation as a promising therapeutic option in colorectal cancer treatment.

Intralesional 5-Fluorouracil in the Treatment of Squamous Cell Carcinoma in an Elderly Patient.

Squamous cell carcinoma (SCC) is the second leading form of skin cancer. In the elderly population, surgery may carry more risk and significant morbidity in comparison to less invasive forms of treatment. This case report describes the successful use of intralesional 5-fluorouracil (IL5-FU) to treat cutaneous squamous cell carcinoma (cSCC). A 98-year-old white woman presented in early May 2017 with a 3.5-cm rapidly growing crusted nodule on her left proximal-lateral arm. She had a past medical history of chronic obstructive pulmonary disease, atrial fibrillation, and heart failure. The patient also had a frail body habitus and weighed 80 pounds. Physical examination revealed a large, ulcerated, crateriform mass on the left proximal-lateral arm. A shave biopsy was performed, which revealed a well-differentiated SCC, composed of nodular masses of neoplastic squamous cells with atypical nuclei, keratin pearl formation, and scattered mitotic figures with surrounding fibrosis and inflammation. The patient was wheelchair-bound and oxygen-dependent and, thus, not considered a good surgical or radiation candidate. Treatment was decided with 5-fluorouracil. At a four-week follow-up appointment, there was no visible or palpable evidence of the tumor. There was no sign of recurrence at three months, indicating treatment success. The patient later died due to cardiac arrest in September 2017. The elderly population with cSCC can benefit from intervention and treatment with IL5-FU when surgery is not an option due to patient comorbidities. IL5-FU can potentially be used in areas where access to a dermatologist, surgeon, or surgical services is limited.