ABSTRACT
Therapeutic fluoropyrimidines 5-fluorouracil (5-FU) and 5-fluorocytosine (5-FC) are in long use for treatment of human cancers and severe invasive fungal infections, respectively. 5-Fluorouridine triphosphate represents a bioactive metabolite of both drugs and is incorporated into target cells' RNA. Here we use the model fungus Saccharomyces cerevisiae to define fluorinated tRNA as a key mediator of 5-FU and 5-FC cytotoxicity when specific tRNA methylations are absent. tRNA methylation deficiency caused by loss of Trm4 and Trm8 was previously shown to trigger an RNA quality control mechanism resulting in partial destabilization of hypomodified tRNAValAAC. We demonstrate that, following incorporation into tRNA, fluoropyrimidines strongly enhance degradation of yeast tRNAValAAC lacking Trm4 and Trm8 dependent methylations. At elevated temperature, such effect occurs already in absence of Trm8 alone. Genetic approaches and quantification of tRNA modification levels reveal that enhanced fluoropyrimidine cytotoxicity results from additional, drug induced uridine modification loss and activation of tRNAValAAC decay involving the exonuclease Xrn1. These results suggest that inhibition of tRNA methylation may be exploited to boost therapeutic efficiency of 5-FU and 5-FC.
Subject(s)
Flucytosine , Fluorouracil , RNA, Transfer , Saccharomyces cerevisiae , Exoribonucleases/metabolism , Exoribonucleases/genetics , Flucytosine/pharmacology , Fluorouracil/pharmacology , Methylation , RNA Stability/drug effects , RNA, Transfer/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae Proteins/genetics , tRNA Methyltransferases/metabolism , tRNA Methyltransferases/genetics , Uridine/metabolismABSTRACT
This study aimed to repurpose the antifungal drug flucytosine (FCN) for anticancer activity together with cocrystals of nutraceutical coformers sinapic acid (SNP) and syringic acid (SYA). The cocrystal screening experiments with SNP resulted in three cocrystal hydrate forms in which two are polymorphs, namely, FCN-SNP F-I and FCN-SNP F-II, and the third one with different stoichiometry in the asymmetric unit (1:2:1 ratio of FCN:SNP:H2O, FCN-SNP F-III). Cocrystallization with SYA resulted in two hydrated cocrystal polymorphs, namely, FCN-SYA F-I and FCN-SYA F-II. All the cocrystal polymorphs were obtained concomitantly during the slow evaporation method, and one of the polymorphs of each system was produced in bulk by the slurry method. The interaction energy and lattice energies of all cocrystal polymorphs were established using solid-state DFT calculations, and the outcomes correlated with the experimental results. Further, the in vitro cytotoxic activity of the cocrystals was determined against DU145 prostate cancer and the results showed that the FCN-based cocrystals (FCN-SNP F-III and FCN-SYA F-I) have excellent growth inhibitory activity at lower concentrations compared with parent FCN molecules. The prepared cocrystals induce apoptosis by generating oxidative stress and causing nuclear damage in prostate cancer cells. The Western blot analysis also depicted that the cocrystals downregulate the inflammatory markers such as NLRP3 and caspase-1 and upregulate the intrinsic apoptosis signaling pathway marker proteins, such as Bax, p53, and caspase-3. These findings suggest that the antifungal drug FCN can be repurposed for anticancer activity.
Subject(s)
Antifungal Agents , Antineoplastic Agents , Apoptosis , Drug Repositioning , Flucytosine , Prostatic Neoplasms , Signal Transduction , Apoptosis/drug effects , Humans , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Antifungal Agents/pharmacology , Antifungal Agents/chemistry , Male , Signal Transduction/drug effects , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Cell Line, Tumor , Drug Repositioning/methods , Flucytosine/pharmacology , Flucytosine/chemistry , Coumaric Acids/chemistry , Coumaric Acids/pharmacology , Gallic Acid/chemistry , Gallic Acid/pharmacology , Gallic Acid/analogs & derivatives , Crystallization , NLR Family, Pyrin Domain-Containing 3 Protein/metabolismABSTRACT
Chromoblastomycosis (CBM) and pheohyphomycosis (PHM) are the most common implantation mycoses caused by dematiaceous fungi. In the past, flucytosine (5-FC) has been used to treat CBM, but development of resistance is common. Carmofur belongs to the same class as 5-FC and has in vitro inhibitory activity against the main agents of CBM and PHM. The aim of this study was to compare the action of these two pyrimidine analog drugs against CBM and PHM agents. The minimum inhibitory concentration (MIC) and the selectivity index based on cytotoxicity tests of these two drugs against some agents of these mycoses were determined, with carmofur presenting a higher selectivity index than 5-FC. Carmofur demonstrated here synergistic interactions with itraconazole and amphotericin B against Exophiala heteromorpha, Fonsecaea pedrosoi, Fonsecaea monophora, and Fonsecaea nubica strains. Additionally, carmofur plus itraconazole demonstrated here synergism against a Phialophora verrucosa strain. To evaluate the development of carmofur resistance, passages in culture medium containing subinhibitory concentrations of this pyrimidine analog were carried out, followed by in vitro susceptibility tests. Exophiala dermatitidis quickly developed resistance, whereas F. pedrosoi took seven passages in carmofur-supplemented medium to develop resistance. Moreover, resistance was permanent in E. dermatitidis but transient in F. pedrosoi. Hence, carmofur has exhibited certain advantages, albeit accompanied by limitations such as the development of resistance, which was expected as with 5-FC. This underscores its therapeutic potential in combination with other drugs, emphasizing the need for a meticulous evaluation of its application in the fight against dematiaceous fungi.
Subject(s)
Chromoblastomycosis , Mycoses , Humans , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Flucytosine/pharmacology , Itraconazole/pharmacology , Itraconazole/therapeutic use , Fungi , Chromoblastomycosis/microbiology , Chromoblastomycosis/veterinary , Mycoses/drug therapy , Mycoses/veterinary , Microbial Sensitivity Tests/veterinaryABSTRACT
BACKGROUND: There are no established clinical breakpoints for antifungal agents against Cryptococcus species; however, epidemiological cut-off values can help distinguish wild-type (WT) isolates without any acquired resistance from non-WT strains, which may harbour resistance mechanisms. PATIENTS/METHODS: We describe the trends of antifungal MICs and percentages of WT C. neoformans species complex (CNSC) isolates processed in our reference laboratory from November 2011 to June 2021. There were only nine isolates in 2011, thus, we included them in the year 2012 for data analysis. Clinical data is also described when available. RESULTS: We identified 632 CNSC, the majority collected from blood (n = 301), cerebrospinal fluid (n = 230), and respiratory (n = 71) sources. The overall percentage of WT isolates for amphotericin B (AMB), 5-flucytosine, and fluconazole was 77%, 98%, and 91%, respectively. We noticed a statistically significant change in the percentage of AMB WT isolates over the years, with 98% of isolates being WT in 2012 compared to 79% in 2021 (p < .01). A similar change was not observed for other antifungal agents. Clinical data was available for 36 patients, primarily non-HIV immunocompromised patients with disseminated cryptococcosis. There were no statistically significant differences in the clinical characteristics and outcomes between patients with WT (58.3%) versus non-WT (41.7%) isolates, but we noticed higher mortality in patients infected with an AMB non-WT CNSC isolate. CONCLUSIONS: We observed an increase in the percentage of AMB non-WT CNSC isolates in the past decade. The clinical implications of this finding warrant further evaluation in larger studies.
Subject(s)
Cryptococcosis , Cryptococcus neoformans , Humans , United States/epidemiology , Antifungal Agents/pharmacology , Cryptococcosis/drug therapy , Cryptococcosis/epidemiology , Cryptococcosis/microbiology , Flucytosine/pharmacology , Amphotericin B/pharmacology , Fluconazole , Microbial Sensitivity TestsABSTRACT
Cancer in dogs has increased in recent years and is a leading cause of death. We have developed a retroviral replicating vector (RRV) that specifically targets cancer cells for infection and replication. RRV carrying a suicide gene induced synchronized killing of cancer cells when administered with a prodrug after infection. In this study, we evaluated two distinct RRVs derived from amphotropic murine leukemia virus (AMLV) and gibbon ape leukemia virus (GALV) in canine tumor models both in vitro and in vivo. Despite low infection rates in normal canine cells, both RRVs efficiently infected and replicated within all the canine tumor cells tested. The efficient intratumoral spread of the RRVs after their intratumoral injection was also demonstrated in nude mouse models of subcutaneous canine tumor xenografts. When both RRVs encoded a yeast cytosine deaminase suicide gene, which converts the prodrug 5-fluorocytosine (5-FC) to the active drug 5-fluorouracil, they caused tumor-cell-specific 5-FC-induced killing of the canine tumor cells in vitro. Furthermore, in the AZACF- and AZACH-cell subcutaneous tumor xenograft models, both RRVs exerted significant antitumor effects. These results suggest that RRV-mediated suicide gene therapy is a novel therapeutic approach to canine cancers.
Subject(s)
Neoplasms , Prodrugs , Mice , Humans , Dogs , Animals , Genetic Therapy/methods , Cell Line, Tumor , Leukemia Virus, Gibbon Ape/genetics , Fluorouracil/pharmacology , Flucytosine/pharmacology , Prodrugs/pharmacology , Genetic Vectors , Cytosine Deaminase/genetics , Neoplasms/drug therapyABSTRACT
A promising de novo approach for the treatment of Castration-resistant prostate cancer (CRPC) exploits cell-mediated enzyme prodrug therapy comprising cytosine deaminase (CD) and fluorouracil (5-FC). The aim of this study was to determine the potential of bacterial CD-overexpressing hTERT-immortalized human adipose stem cells (hTERT-ADSC.CD) to suppress CRPC. A lentiviral vector encoding a bacterial CD gene was used to transfect and to generate the hTERT-ADSC.CD line. The ability of the cells to migrate selectively towards malignant cells was investigated in vitro. PC3 and hTERT-ADSC.CD cells were co-cultured. hTERT-ADSC.CD and 1 × 106 PC3 cells were administered to nude mice via intracardiac and subcutaneous injections, respectively, and 5-FC was given for 14 days. hTERT-ADSC.CD were successfully engineered. Enhanced in vitro hTERT-ADSC.CD cytotoxicity and suicide effect were evident following administration of 5 µM 5-FC. hTERT-ADSC.CD, together with 5-FC, augmented the numbers of PC3 cells undergoing apoptosis. In comparison to controls administered hTERT-ADSC.CD monotherapy, hTERT-ADSC.CD in combination with 5-FC demonstrated a greater suppressive effect on tumor. In CPRC-bearing mice, tumor suppression was enhanced by the combination of CD-overexpressing ADSC and the prodrug 5-FC. Stem cells exhibiting CD gene expression are a potential novel approach to treatment for CRPC.
Subject(s)
Cytosine Deaminase , Flucytosine , Prostatic Neoplasms, Castration-Resistant , Telomerase , Animals , Humans , Male , Mice , Adipose Tissue/cytology , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cytosine Deaminase/genetics , Cytosine Deaminase/metabolism , Flucytosine/pharmacology , Mice, Nude , PC-3 Cells , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/therapy , Stem Cells , Telomerase/genetics , Telomerase/metabolism , Xenograft Model Antitumor AssaysABSTRACT
The yeast cytosine deaminase (yCD) enzyme/5-fluorocytosine prodrug system is a promising candidate for targeted chemotherapeutics. After conversion of the prodrug into the toxic chemotherapeutic drug, 5-fluorouracil (5-FU), the slow product release from the enzyme limits the overall catalytic efficiency of the enzyme/prodrug system. Here, we present a computational study of the product release of the anticancer drug, 5-FU, from yCD using metadynamics. We present a comparison of the 5-FU drug to the natural enzyme product, uracil. We use volume-based metadynamics to compute the free energy landscape for product release and show a modest binding affinity for the product to the enzyme, consistent with experiments. Next, we use infrequent metadynamics to estimate the unbiased release rate from Kramers time-dependent rate theory and find a favorable comparison to experiment with a slower rate of product release for the 5-FU system. Our work demonstrates how adaptive sampling methods can be used to study the protein-ligand unbinding process for engineering enzyme/prodrug systems and gives insights into the molecular mechanism of product release for the yCD/5-FU system.
Subject(s)
Antineoplastic Agents , Prodrugs , Saccharomyces cerevisiae , Cytosine Deaminase/chemistry , Cytosine Deaminase/metabolism , Fluorouracil/metabolism , Flucytosine/chemistry , Flucytosine/metabolism , Prodrugs/chemistryABSTRACT
A 3-year-old boy presented with acute headache, vomiting and right focal clonic seizures without history of fever, joint pain or altered sensorium. Neuroimaging showed multifocal contrast enhancing lesions with significant perilesional edema. CECT chest and abdomen showed multiple variable sized nodules in the lungs and hypodense lesion in liver with mesenteric lymphadenopathy. There was persistent eosinophilia with maximum upto 35 %. Liver biopsy and brain biopsy revealed Cladophialophora bantiana. He was treated with IV liposomal amphotericin and voriconazole for 6 weeks with repeat neuroimaging showing more than 50 % resolution of the intracranial lesions. He was transitioned to oral combination of flucytosine and voriconazole. At 14 months follow-up, he remained symptom free with complete radiological resolution of the lesions and no eosinophilia. High suspicion, an aggressive approach in obtaining microbiological diagnosis and timely combination antifungal therapy may give satisfactory outcome without surgery.
Subject(s)
Amphotericin B , Antifungal Agents , Ascomycota , Immunocompetence , Phaeohyphomycosis , Humans , Male , Child, Preschool , Antifungal Agents/therapeutic use , Ascomycota/isolation & purification , Phaeohyphomycosis/microbiology , Phaeohyphomycosis/diagnosis , Phaeohyphomycosis/drug therapy , Amphotericin B/therapeutic use , Voriconazole/therapeutic use , Flucytosine/therapeutic use , Flucytosine/administration & dosageABSTRACT
The opportunistic fungal infection cryptococcal meningoencephalitis is a major cause of death among people living with HIV in sub-Saharan Africa. We report pharmacokinetic (PK) and safety data from a randomized, four-period crossover phase I trial of three sustained-release (SR) oral pellet formulations of 5-flucytosine conducted in South Africa. These formulations were developed to require less frequent administration, to provide a convenient alternative to the current immediate release (IR) formulation, A. Formulations B, C, and D were designed to release 5-flucytosine as a percentage of the nominal dose in vitro. We assessed their safety and PK profiles in a single dose (1 × 3000 mg at 0 h), relative to commercial IR tablets (Ancotil 500 mg tablets; 3 × 500 mg at 0 h and 3 × 500 mg at 6 h) in healthy, fasted participants. Forty-two healthy participants were included. All treatments were well-tolerated. The primary PK parameters, maximum observed plasma concentration (Cmax ) and area under the concentration-time profiles, were significantly lower for the SR formulations than for the IR tablets, and the geometric mean ratios fell outside the conventional bioequivalence limits. The median maximum time to Cmax was delayed for the SR pellets. Physiologically-based PK modeling indicated a twice-daily 6400 mg dose of SR formulation D in fasted condition would be optimal for further clinical development. This regimen is predicted to result in a rapid steady-state plasma exposure with effective and safe trough plasma concentration and Cmax values, within the therapeutic boundaries relative to plasma exposure after four times per day administration of IR tablets (PACTR202201760181404).
Subject(s)
Flucytosine , Humans , Biological Availability , Healthy Volunteers , Cross-Over Studies , Delayed-Action Preparations , Tablets , Drug Implants , Administration, OralABSTRACT
BACKGROUND: Cryptococcosis is an invasive, opportunistic fungal infection seen especially in human immunodeficiency virus (HIV) infected patients. Cryptococcal meningitis (CM) is the second leading cause of mortality in HIV patients. We report a case of disseminated cryptococcosis presenting with altered mental status in a newly diagnosed HIV infection. METHODS AND RESULTS: A 50-year-old with a short history of altered mental sensorium and a history of low-grade fever and weight loss for few months presented at a tertiary care hospital in North India. He was detected positive for HIV-1. Cryptococcal antigen (CRAG) was positive in Cerebrospinal fluid (CSF), and negative in serum. The fungal culture in CSF was sterile while the fungal blood culture grew Cryptococcus neoformans. The patient was treated with single high-dose Liposomal Amphotericin B (LAmB) therapy followed by Fluconazole and Flucytosine for the next two weeks followed by fluconazole daily for consolidation and maintenance therapy. Antiretroviral therapy (ART) was started 4 weeks after induction therapy. After 6 months, the patient is doing fine. CONCLUSION: Single dose LAmB along with the backbone of fluconazole and flucytosine appears promising in disseminated cryptococcal infection in HIV-infected individuals.
Subject(s)
Amphotericin B , Antifungal Agents , Cryptococcosis , Cryptococcus neoformans , Flucytosine , HIV Infections , Humans , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Male , Antifungal Agents/therapeutic use , Antifungal Agents/administration & dosage , Middle Aged , Cryptococcus neoformans/isolation & purification , Cryptococcus neoformans/drug effects , HIV Infections/complications , Cryptococcosis/drug therapy , Cryptococcosis/diagnosis , Cryptococcosis/microbiology , Treatment Outcome , Flucytosine/therapeutic use , Flucytosine/administration & dosage , AIDS-Related Opportunistic Infections/drug therapy , AIDS-Related Opportunistic Infections/diagnosis , AIDS-Related Opportunistic Infections/microbiology , Fluconazole/therapeutic use , Fluconazole/administration & dosage , Meningitis, Cryptococcal/drug therapy , Meningitis, Cryptococcal/diagnosis , Meningitis, Cryptococcal/microbiology , IndiaABSTRACT
There are many therapeutic modalities for plantar warts, however treating it remains challenging. Intralesional injection of 5-fluorouarcil and combined digoxin and furosemide were observed to be effective and safe, however no comparison study between them was done. Our study was conducted to evaluate the efficacy of both therapies in the treatment of plantar warts. 90 adult patients with multiple recalcitrant plantar warts were included in our study. They were randomly allocated to one of three groups; combined digoxin and furosemide, 5-fluorouarcil, or normal saline group. Fortnightly injections were done into all studied warts till complete clearance or up to 5 sessions. Warts were evaluated clinically and dermoscopically. Clinical response was reported in 24 patients (80%) of the combined digoxin and furosemide group with 40% complete response and in 24 patients (80%) of the 5-fluorouarcil group with 33.3% complete response. No statistically significant difference was observed between the two groups concerning efficacy and safety. Intralesional injection of 5-fluorouarcil and combined digoxin and furosemide are nearly equivalent in efficacy and safety for plantar wart treatment. Dermoscopy helps to take the truthful judgment about complete clearance of warts.
Subject(s)
Digoxin , Furosemide , Injections, Intralesional , Warts , Humans , Furosemide/administration & dosage , Male , Female , Adult , Warts/drug therapy , Digoxin/administration & dosage , Treatment Outcome , Prospective Studies , Young Adult , Middle Aged , Drug Therapy, Combination/methods , Adolescent , Dermoscopy , Flucytosine/administration & dosageABSTRACT
OBJECTIVES: We aimed to describe features and outcomes of cryptococcosis among HIV-seronegative individuals in a large surveillance network for cryptococcosis in France. METHODS: We included incident cases of cryptococcosis in HIV-seronegative individuals from 2005 to 2020. We compared patient characteristics, disease presentations, cryptococcal antigen results, and induction antifungal treatments according to underlying disease. We examined factors associated with 90-day mortality. Among patients with disseminated infections, we investigated whether receipt of flucytosine and polyene combination was associated with lower mortality. RESULTS: Among 652 individuals, 209 (32.1%) had malignancy, 130 (19.9%) were solid-organ transplant recipients, 204 (31.3%) had other immunocompromising conditions, and 109 (16.7%) had no reported underlying factor. The commonest presentations were disseminated infections (63.3%, 413/652) and isolated pulmonary infections (25.3%, 165/652). Solid-organ transplant patients were most likely to have disseminated infections and a positive serum cryptococcal antigen result. Patients with malignancy were older and less likely to receive a flucytosine-containing regimen for disseminated infections than others (58.7%, 78/133 vs. 73.2%, 194/265; p 0.029). The crude 90-day case-fatality ratio was 27.2% (95% CI, 23.5%-31.1%). Age ≥60 years (aOR: 2.75 [1.78-4.26]; p < 0.001), meningitis/fungaemia (aOR: 4.79 [1.80-12.7]; p 0.002), and malignancy (aOR: 2.4 [1.14-5.07]; p 0.02) were associated with higher 90-day mortality. Receipt of flucytosine and polyene combination was associated with lower 90-day mortality (aOR: 0.40 [0.23-0.71]; p 0.002) in multivariable analysis and inverse probability of treatment weighted analysis (aOR: 0.45 [0.25-0.80]; p 0.006). DISCUSSION: HIV-seronegative individuals with cryptococcosis comprise a wide range of underlying conditions with different presentations and outcomes, requiring a tailored approach to diagnosis and management.
Subject(s)
Antifungal Agents , Cryptococcosis , Humans , France/epidemiology , Female , Male , Cryptococcosis/epidemiology , Cryptococcosis/mortality , Middle Aged , Adult , Cross-Sectional Studies , Antifungal Agents/therapeutic use , Aged , Flucytosine/therapeutic use , HIV Seronegativity , Polyenes/therapeutic use , Young Adult , Immunocompromised HostABSTRACT
OBJECTIVES: The relationship between antifungal susceptibility and mortality of cryptococcal meningitis (CM) in HIV-negative patients is poorly understood. METHODS: We conducted a retrospective analysis of 1-year follow-up of 200 HIV-negative CM patients with an initial cerebrospinal fluid (CSF) culture for Cryptococcus neoformans. According to the cut-off values of minimum inhibitory concentration (MIC), two groups of five antifungal agents were classified: amphotericin B (AmB), ≤0.5 µg/mL, >0.5 µg/mL; 5-flucytosine (5-FC), ≤4 µg/mL, >4 µg/mL; fluconazole (FLU), ≤4 µg/mL, >4 µg/mL; itraconazole (ITR), ≤0.125 µg/mL, >0.125 µg/mL; and voriconazole (VOR), <0.25 µg/mL, ≥0.25 µg/mL. Comparisons were performed to analyse clinical features, laboratory, modified Rankin Scale (mRS) scores, and CSF findings under different prognosis outcomes in 1-year. RESULTS: All of Cryptococcus neoformans isolates were sensitive to AmB and VOR, most of them were sensitive to 5-FC and FLU (95.5% and 90.5%, respectively) while only 55.0% of them were susceptible to ITR. Minimum inhibitory concentrations of ITR and VOR were significantly related to baseline mRS scores. All-cause mortality was not significantly related to MICs in Cryptococcus neoformans strains. The combination of actual antifungal agents and two groups of the MICs values for antifungal agents had no significant effects on all-cause mortality. CONCLUSION: Most Cryptococcus neoformans isolates were sensitive to AmB, VOR, 5-FC, and FLU. Because of the small number of deaths, we are not able to comment on whether MIC is associated with mortality of CM in HIV-negative patients.
Subject(s)
Cryptococcosis , Cryptococcus neoformans , HIV Infections , Meningitis, Cryptococcal , Humans , Antifungal Agents/pharmacology , Antifungal Agents/therapeutic use , Meningitis, Cryptococcal/drug therapy , Meningitis, Cryptococcal/complications , Meningitis, Cryptococcal/microbiology , Retrospective Studies , Fluconazole/pharmacology , Cryptococcosis/complications , Cryptococcosis/drug therapy , Cryptococcosis/microbiology , Amphotericin B/pharmacology , Flucytosine/pharmacology , Voriconazole/pharmacology , Voriconazole/therapeutic use , Itraconazole/pharmacology , HIV Infections/drug therapyABSTRACT
Cryptococcus neoformans is at the top of the list of "most wanted" human pathogens. Only three classes of antifungal drugs are available for the treatment of cryptococcosis. Studies on antifungal resistance mechanisms are limited to the investigation of how a particular antifungal drug induces resistance to a particular drug, and the impact of stresses other than antifungals on the development of antifungal resistance and even cross-resistance is largely unexplored. The endoplasmic reticulum (ER) is a ubiquitous subcellular organelle of eukaryotic cells. Brefeldin A (BFA) is a widely used chemical inducer of ER stress. Here, we found that both weak and strong selection by BFA caused aneuploidy formation in C. neoformans, mainly disomy of chromosome 1, chromosome 3, and chromosome 7. Disomy of chromosome 1 conferred cross-resistance to two classes of antifungal drugs: fluconazole and 5-flucytosine, as well as hypersensitivity to amphotericin B. However, drug resistance was unstable, due to the intrinsic instability of aneuploidy. We found overexpression of AFR1 on Chr1 and GEA2 on Chr3 phenocopied BFA resistance conferred by chromosome disomy. Overexpression of AFR1 also caused resistance to fluconazole and hypersensitivity to amphotericin B. Furthermore, a strain with a deletion of AFR1 failed to form chromosome 1 disomy upon BFA treatment. Transcriptome analysis indicated that chromosome 1 disomy simultaneously upregulated AFR1, ERG11, and other efflux and ERG genes. Thus, we posit that BFA has the potential to drive the rapid development of drug resistance and even cross-resistance in C. neoformans, with genome plasticity as the accomplice.
Subject(s)
Aneuploidy , Antifungal Agents , Brefeldin A , Cryptococcus neoformans , Drug Resistance, Fungal , Cryptococcus neoformans/drug effects , Cryptococcus neoformans/genetics , Brefeldin A/pharmacology , Antifungal Agents/pharmacology , Drug Resistance, Fungal/genetics , Fluconazole/pharmacology , Amphotericin B/pharmacology , Fungal Proteins/genetics , Fungal Proteins/metabolism , Microbial Sensitivity Tests , Flucytosine/pharmacology , Humans , Endoplasmic Reticulum Stress/drug effectsABSTRACT
Primary cerebral phaeohyphomycosis is a life-threatening disease caused by neurotropic dematiaceous fungi. At present, there are no consensus guidelines regarding optimal antifungal therapy in such cases. Generally, a combination of antifungal agents is recommended for treatment. However, the activities of antifungal combinations against these fungi have not been investigated. In this study, we evaluated the in vitro activities of 13 double and five triple antifungal combinations against clinical isolates of Cladophialophora bantiana (n = 7), Fonsecaea monophora (n = 2), and Cladosporium cladosporioides (n = 1), using a simplified checkerboard procedure. The minimum inhibitory concentrations (MICs) of nine antifungal drugs were determined by the broth microdilution method, and the interaction between antifungal agents in each combination was assessed by the fractional inhibitory concentration index. Excellent activity was observed for posaconazole and itraconazole. Flucytosine had potent activity against C. bantiana but was ineffective against F. monophora, and C. cladosporioides. The echinocandins demonstrated high MICs for all the isolates. Synergistic interactions were observed for all the double combinations, except when itraconazole was combined with either amphotericin B or flucytosine. The combination of amphotericin B with caspofungin showed synergistic interactions against 40% of the isolates. Antagonism was observed with isavuconazole-flucytosine combination against two C. bantiana isolates. The triple combinations of caspofungin and flucytosine with amphotericin B or posaconazole were synergistic against one isolate of F. monophora. For C. cladosporioides, synergy was observed for the triple combination of amphotericin B with caspofungin and flucytosine. Our results indicate that combination of caspofungin with amphotericin B or a triazole, with or without 5-flucytosine has great potential against neurotropic dematiaceous fungi.IMPORTANCEThis research uses a modified version of the checkerboard assay to standardize the in vitro testing of double and triple combinations of antifungal agents against neurotropic dematiaceous fungi. Antifungal combination therapy is associated with improved outcomes in cerebral phaeohyphomycosis. In this study, we demonstrate that posaconazole is the single most active antifungal drug against this group of fungi. The double combination of amphotericin B with caspofungin or a trizole, and the triple combinations of caspofungin and flucytosine with amphotericin B or posaconazole might hold promise in the treatment of cerebral phaeohyphomycosis. Our findings will guide in developing optimal therapeutic strategies for these refractory infections.
Subject(s)
Antifungal Agents , Cerebral Phaeohyphomycosis , Drug Synergism , Microbial Sensitivity Tests , Antifungal Agents/pharmacology , Humans , Cerebral Phaeohyphomycosis/drug therapy , Cerebral Phaeohyphomycosis/microbiology , Ascomycota/drug effects , Cladosporium/drug effects , Triazoles/pharmacology , Drug Therapy, Combination , Flucytosine/pharmacology , Itraconazole/pharmacology , Echinocandins/pharmacologyABSTRACT
INTRODUCCIÓN: las infecciones fúngicas ocasionadas por levaduras del género Cándida son extremadamente comunes en mujeres de edad reproductiva, y constituyen un motivo de atención medica de salud. OBJETIVO: evaluar la susceptibilidad de Cándidas spp, mediante el método colorimétrico (Integral Yeast System Plus). MÉTODO: fue de tipo descriptivo, transversal; se recopiló información mediante observación directa en campo y el análisis documental para obtener información bibliográfica de tipo secundaria. RESULTADOS: de los 72 casos encontrados de Cándida Albicans revela que son susceptibles a la anfotericina B (2ug/ml); de los 5 casos encontrados de Cándida Krusei revela que son sensibles a la Anfotericina B (2ug/ml); De 1 caso encontrado de Cándida Parapsilosis revela sensibilidad en la Nistatina (1.25ug/ml). En este estudio la prevalencia de la infección por Cándida fue del (44.98%). CONCLUSIONES: Cándida Albicans fue la especie más común aislada en las mujeres embarazadas representando un 72%, En la evaluación de la susceptibilidad a través del kit Integral System Yeast Plus se obtuvo que Cándida Albicans es susceptible a Anfotericina B, Flucitosina entre otros, en Cándida Glabrata se obtuvo que es sensible a la Nistatina, Anfotericina B, susceptible entre otros, en Cándida Krusei se obtuvo que es sensible a la Anfotericina B, Clotrimazol, Miconazol, susceptibles a la Nistatina, Voriconazol y resistente a la Flucitosina, Ketoconazol, Itraconazol y Fluconazol.
INTRODUCTION: fungal infections caused by yeast of the genus Candida are extremely common in women of reproductive age, and constitute a reason for medical health care. OBJECTIVE: to evaluate the susceptibility of Candida spp, using the colorimetric method (Integral Yeast System Plus). METHOD: it was descriptive, transversal; Information was collected through direct observation in the field and documentary analysis to obtain secondary bibliographic information. RESULTS: of the 72 cases found, Candida Albicans reveals that they are susceptible to amphotericin B (2ug / ml); of the 5 cases found, Candida Krusei reveals that they are sensitive to Amphotericin B (2ug / ml); Of 1 case found of Candida Parapsilosis reveals sensitivity in Nystatin (1.25ug / ml). In this study, the prevalence of Candida infection was (44.98%). CONCLUSIONS: Candida Albicans was the most common species isolated in pregnant women, representing 72%. In the evaluation of susceptibility through the Integral System Yeast Plus kit it was obtained that Candida Albicans is susceptible to Amphotericin B, Flucytosine among others, in Candida Glabrata was obtained that it is sensitive to Nystatin, Amphotericin B, susceptible among others, in Candida Krusei it was obtained that it is sensitive to Amphotericin B, Clotrimazole, Miconazole, susceptible to Nystatin, Voriconazole and resistant to Flucytosin, Ketoconazole, Itraconazole and Fluconazole.
INTRODUÇÃO: as infecções fúngicas causadas por leveduras do gênero Candida são extremamente comuns em mulheres em idade reprodutiva e constituem motivo de cuidados médicos. OBJETIVO: avaliar a suscetibilidade de Candida spp, por meio do método colorimétrico (Integral Yeast System Plus). MÉTODO: foi descritivo, transversal; as informações foram coletadas por meio de observação direta em campo e análise documental para obtenção de informações bibliográficas secundárias. RESULTADOS: Dos 72 casos encontrados, Cândida Albicans revelou ser suscetíveis à anfotericina B (2ug /ml); dos 5 casos encontrados, Candida Krusei revela que são sensíveis à Anfotericina B (2ug / ml); de 1 caso encontrado de Candida Parapsilosis revela sensibilidade na Nistatina (1,25ug / ml). Neste estudo, a prevalência de infecção por Candida foi (44,98%). CONCLUSÕES: Cândida Albicans foi a espécie mais comum isolada em gestantes, representando 72%. Na avaliação da susceptibilidade através do kit Integral System Yeast Plus foi obtido que Candida Albicans é suscetível à Anfotericina B, Flucitosina entre outras, em Cândida Glabrata foi obtido que é sensível a Nistatina, Anfotericina B, suscetível entre outras, em Candida Krusei foi obtido que é sensível a Anfotericina B, Clotrimazol, Miconazol, suscetível a Nistatina, Voriconazol e resistente a Flucitosina, Cetoconazol, Itraconazol e Fluconazol.
Subject(s)
Humans , Female , Pregnancy , Adult , Candida , Candida albicans , Amphotericin B , Colorimetry , Candida glabrata , Pregnant Women , Fluconazole , Prevalence , Clotrimazole , Itraconazole , Voriconazole , Flucytosine , Candida parapsilosis , Infections , MiconazoleABSTRACT
PURPOSE: In the present study, human neural stem cells (hNSCs) with tumor-tropic behavior were used as drug delivery vehicle to selectively target melanoma. A hNSC line (HB1.F3) was transduced into two types: one expressed only the cytosine deaminase (CD) gene (HB1.F3. CD) and the other expressed both CD and human interferon-β (IFN-β) genes (HB1.F3.CD. IFN-β). MATERIALS AND METHODS: This study verified the tumor-tropic migratory competence of engineered hNSCs on melanoma (A375SM) using a modified Boyden chamber assay in vitro and CM-DiI staining in vivo. The antitumor effect of HB1.F3.CD and HB1.F3.CD.IFN-β on melanoma was also confirmed using an MTT assay in vitro and xenograft mouse models. RESULTS: A secreted form of IFN-β from the HB1.F3.CD.IFN-β cells modified the epithelial-mesenchymal transition (EMT) process and metastasis of melanoma. 5-Fluorouracil treatment also accelerated the expression of the pro-apoptotic protein BAX and decelerated the expression of the anti-apoptotic protein Bcl-xL on melanoma cell line. CONCLUSION: Our results illustrate that engineered hNSCs prevented malignant melanoma cells from proliferating in the presence of the prodrug, and the form that secreted IFN-β intervened in the EMT process and melanoma metastasis. Hence, neural stem cell-directed enzyme/prodrug therapy is a plausible treatment for malignant melanoma.
Subject(s)
Animals , Humans , Mice , Cell Line , Cytosine Deaminase , Epithelial-Mesenchymal Transition , Flucytosine , Fluorouracil , Heterografts , In Vitro Techniques , Melanoma , Mental Competency , Neoplasm Metastasis , Neural Stem Cells , Stem CellsABSTRACT
This is the first case report to describe the tumor regressive effect of systemic human neural stem cell (NSC)/5-fluorocytosine (5-FC) therapy on canine metastatic lung tumor. The therapeutic effects appeared approximately two weeks after 5-FC administration. Thoracic radiographs revealed a reduced number of lung nodules and decreased nodule size. However, there were no significant antitumor effects on primary lesions in abdominal organs. In conclusion, human NSC/5-FC prodrug therapy can secure patient quality of life with the same or more therapeutic effects and fewer side effects than other recommended chemotherapies.
Subject(s)
Humans , Drug Therapy , Flucytosine , Genetic Therapy , Lung , Neural Stem Cells , Quality of Life , Therapeutic UsesABSTRACT
PURPOSE: Genetically engineered stem cells may be advantageous for gene therapy against various human cancers due to their inherent tumor-tropic properties. In this study, genetically engineered human neural stem cells (HB1.F3) expressing Escherichia coli cytosine deaminase (CD) (HB1.F3.CD) and human interferon-β (IFN-β) (HB1.F3.CD.IFN-β) were employed against lymph node–derived metastatic colorectal adenocarcinoma. MATERIALS AND METHODS: CD can convert a prodrug, 5-fluorocytosine (5-FC), to active 5-fluorouracil, which inhibits tumor growth through the inhibition of DNA synthesis,while IFN-β also strongly inhibits tumor growth by inducing the apoptotic process. In reverse transcription polymerase chain reaction analysis, we confirmed that HB1.F3.CD cells expressed the CD gene and HB1.F3.CD.IFN-β cells expressed both CD and IFN-β genes. RESULTS: In results of a modified trans-well migration assay, HB1.F3.CD and HB1.F3.CD.IFN-β cells selectively migrated toward SW-620, human lymph node–derived metastatic colorectal adenocarcinoma cells. The viability of SW-620 cells was significantly reduced when co-cultured with HB1.F3.CD or HB1.F3.CD.IFN-β cells in the presence of 5-FC. In addition, it was found that the tumor-tropic properties of these engineered human neural stem cells (hNSCs) were attributed to chemoattractant molecules including stromal cell-derived factor 1, c-Kit, urokinase receptor, urokinase-type plasminogen activator, and C-C chemokine receptor type 2 secreted by SW-620 cells. In a xenograft mouse model, treatment with hNSC resulted in significantly inhibited growth of the tumor mass without virulent effects on the animals. CONCLUSION: The current results indicate that engineered hNSCs and a prodrug treatment inhibited the growth of SW-620 cells. Therefore, hNSC therapy may be a clinically effective tool for the treatment of lymph node metastatic colorectal cancer.