ROS-inducible DNA cross-linking agent as a new anticancer prodrug building block.
Ontology highlight
ABSTRACT:
SUBMITTER: Cao S
PROVIDER: S-EPMC3535311 | biostudies-literature | 2012 Mar
REPOSITORIES: biostudies-literature
Publications
ROS-inducible DNA cross-linking agent as a new anticancer prodrug building block.
Cao Sheng S Wang Yibin Y Peng Xiaohua X
Chemistry (Weinheim an der Bergstrasse, Germany) 20120229 13
Similar Datasets
Project description:The major concern for anticancer chemotherapeutic agents is the host toxicity. The development of anticancer prodrugs targeting the unique biochemical alterations in cancer cells is an attractive approach to achieve therapeutic activity and selectivity. We designed and synthesized a new type of nitrogen mustard prodrug that can be activated by high level of reactive oxygen species (ROS) found in cancer cells to release the active chemotherapy agent. The activation mechanism was determined by NMR analysis. The activity and selectivity of these prodrugs toward ROS was determined by measuring DNA interstrand cross-links and/or DNA alkylations. These compounds showed 60-90% inhibition toward various cancer cells, while normal lymphocytes were not affected. To the best of our knowledge, this is the first example of H(2)O(2)-activated anticancer prodrugs.
| S-EPMC3265938 | biostudies-literature
Project description:We have previously shown that spores of the nonpathogenic clostridial strain C. sporogenes genetically engineered to express the E. coli-derived cytosine deaminase gene are effective in converting systemically injected nontoxic 5-fluorocytosine into the toxic anticancer drug 5-fluorouracil, thereby producing tumor-specific antitumor activity. To improve the expression of E. coli-derived genes with this system, we first replaced the original fdP promoter in the vector with one of two powerful endogenous clostridial promoters: that of the thiolase gene (thlP) and that for the clostridial transcription factor abrB310 (abrBP). These substitutions improved protein expression levels of the prodrug-activating genes by 2- to 3-fold in comparison with fdP-driven expression. However, despite these strong promoters, we found much higher expression of the nitroreductase (NTR) protein in the E. coli host compared with the clostridial host, which we hypothesized could be the result of different codon use between the two organisms. To test this, we constructed new expression vectors with an artificially synthesized NTR gene using optimized clostridial codons (sNTR). Results from both enzymatic assays and Western blots of cell extracts from clostridial transformants harboring plasmid constructs of thlP-sNTR and abrBP-sNTR showed that the expression and activity of the NTR gene product was increased by approximately 20-fold compared with the original construct. In vivo studies with i.v. administered sNTR-expressing C. sporogenes spores in SiHa tumor-bearing mice showed significantly improved antitumor efficacy when combined with either 5-aziridinyl-2,4-dinitrobenzamide (CB1954) or the novel dinitrobenzamide mustard prodrug, PR-104.
| S-EPMC2596930 | biostudies-literature
Project description:Reducing host toxicity is one of the main challenges of cancer chemotherapy. Many tumor cells contain high levels of ROS that make them distinctively different from normal cells. We report a series of ROS-activated aromatic nitrogen mustards that selectively kill chronic lymphocytic leukemia (CLL) over normal lymphocytes. These agents showed powerful DNA cross-linking abilities when coupled with H2O2, one of the most common ROS in cancer cells, whereas little DNA cross-linking was detected without H2O2. Consistent with chemistry observation, in vitro cytotoxicity assay demonstrated that these agents induced 40-80% apoptosis in primary leukemic lymphocytes isolated from CLL patients but less than 25% cell death to normal lymphocytes from healthy donors. The IC50 for the most potent compound (2) was ~5 μM in CLL cells, while the IC50 was not achieved in normal lymphocytes. Collectively, these data provide utility and selectivity of these agents that will inspire further and effective applications.
| S-EPMC4133937 | biostudies-literature
Project description:In recent decades, drug delivery systems (DDSs) based on polymer nanoparticles have been explored due to their potential to deliver drugs with poor water solubility. Some of the limitations of nanoparticle-based DDSs can be overcome by developing an appropriate polymer prodrug. In this work, poly(NIPA)-b-poly(HMNPPA)-b-poly(PEGMA-stat-BA) was synthesized using reversible addition fragmentation chain transfer polymerization and Chlorambucil (Cbl), an anticancer drug, was conjugated to the copolymer via 3-(3-(hydroxymethyl)-4-nitrophenoxy)propyl acrylate (HMNPPA) units to prepare the prodrug. A few biotin acrylate (BA) units were also incorporated to bring potential targeting capability to the prodrug in the copolymer. This polymer prodrug formed spherical micellar nanoparticles in physiological conditions, which were characterized by dynamic light scattering and transmission electron microscopy measurements. The very low critical aggregation concentration (cac) (0.011 mg/mL) of the prodrug, as measured from Nile Red fluorescence, makes it stable against dilution. The polymer prodrug was shown to release Cbl on photoirradiation by soft UV (λ ≥ 365 nm) and laser (λ = 405 nm) light. The prodrug micellar nanoparticles were capable of encapsulating a second drug (doxorubicin, DOX) in their hydrophobic core. On photoirradiation with UV and laser light of the DOX-loaded nanoparticles, both Cbl and DOX were released. Light-induced breaking of photolabile ester bond resulted in the release of Cbl and caused disruption of the nanoparticles facilitating release of DOX. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay confirmed the nontoxicity of the polymers and effectiveness of the dual drug-loaded micellar nanoparticles toward cancer cells. Confocal microscopy results showed a better cellular internalization capability of the DOX-loaded nanoparticles in cancer cells, possibly due to the presence of cancer cell targeting biotin molecules in the polymer. This new photoresponsive potentially biocompatible and cancer cell-targeted polymer prodrug may be useful for delivery of single and/or multiple hydrophobic drugs.
| S-EPMC6045338 | biostudies-literature
Project description:DNA-encoded library technology grants access to nearly infinite opportunities to explore the chemical structure space for drug discovery. Successful navigation depends on the design and synthesis of libraries with appropriate physicochemical properties (PCPs) and structural diversity while aligning with practical considerations. To this end, we analyze combinatorial library design constraints including the number of chemistry cycles, bond construction strategies, and building block (BB) class selection in pursuit of ideal library designs. We compare two-cycle library designs (amino acid + carboxylic acid, primary amine + carboxylic acid) in the context of PCPs and chemical space coverage, given different BB selection strategies and constraints. We find that broad availability of amines and acids is essential for enabling the widest exploration of chemical space. Surprisingly, cost is not a driving factor, and virtually, the same chemical space can be explored with "budget" BBs.
| S-EPMC11200258 | biostudies-literature
Project description:DNA-encoded libraries (DELs) provide the means to make and screen millions of diverse compounds against a target of interest in a single experiment. However, despite producing large volumes of binding data at a relatively low cost, the DEL selection process is susceptible to noise, necessitating computational follow-up to increase signal-to-noise ratios. In this work, we present a set of informatics tools to employ data from prior DEL screen(s) to gain information about which building blocks are most likely to be productive when designing new DELs for the same target. We demonstrate that similar building blocks have similar probabilities of forming compounds that bind. We then build a model from the inference that the combined behavior of individual building blocks is predictive of whether an overall compound binds. We illustrate our approach on a set of three-cycle OpenDEL libraries screened against soluble epoxide hydrolase (sEH) and report performance of more than an order of magnitude greater than random guessing on a holdout set, demonstrating that our model can serve as a baseline for comparison against other machine learning models on DEL data. Lastly, we provide a discussion on how we believe this informatics workflow could be applied to benefit researchers in their specific DEL campaigns.
| S-EPMC10466377 | biostudies-literature
Project description:Chick oviduct progesterone-receptor proteins were treated in cytosol with the reversible cross-linking reagent methyl 4-mercaptobutyrimidate. The product of the reaction was a 7S complex that could be detected and recovered after sucrose-density-gradient centrifugation in 0.3M-KCl. The extent of the reaction was dependent on the concentration of methyl 4-mercaptobutyrimidate and independent of the presence of bound hormone, since unlabelled receptors could also be cross-linked. The cross-linking reaction required conditions in which the cytosol 6S complex was preserved. A Stokes radius of 7.3 nm was determined by gel filtration in Agarose A-1.5 m in 0.3 M-KCl. The sedimentation coefficient, which was also determined in 0.3 M-KCl, allowed us to calculate a mol. wt. of 228,000. We were also able to cross-link partially purified receptor forms isolated by using an Agarose A-15 m column. On reduction with beta-mercaptoethanol the complex broke down to 4S monomers that were identified by DEAE-cellulose and phosphocellulose chromatography, adsorption on DNA-cellulose and gel filtration in an Agarose A-1.5 m column. In most cases, A and B receptor proteins were released in equivalent amounts, implying that the cross-linked form was an A-B complex.
| S-EPMC1161142 | biostudies-other
Project description:DNA interstrand cross-links (ICLs) represent lethal DNA damage, because they block transcription, replication, and segregation of DNA. Because of their genotoxicity, agents inducing ICLs are often used in antitumor therapy. The repair of ICLs is complex and involves proteins belonging to nucleotide excision, recombination, and translesion DNA repair pathways in Escherichia coli, Saccharomyces cerevisiae, and mammals. We cloned and analyzed mammalian homologs of the S. cerevisiae gene SNM1 (PSO2), which is specifically involved in ICL repair. Human Snm1, a nuclear protein, was ubiquitously expressed at a very low level. We generated mouse SNM1(-/-) embryonic stem cells and showed that these cells were sensitive to mitomycin C. In contrast to S. cerevisiae snm1 mutants, they were not significantly sensitive to other ICL agents, probably due to redundancy in mammalian ICL repair and the existence of other SNM1 homologs. The sensitivity to mitomycin C was complemented by transfection of the human SNM1 cDNA and by targeting of a genomic cDNA-murine SNM1 fusion construct to the disrupted locus. We also generated mice deficient for murine SNM1. They were viable and fertile and showed no major abnormalities. However, they were sensitive to mitomycin C. The ICL sensitivity of the mammalian SNM1 mutant suggests that SNM1 function and, by implication, ICL repair are at least partially conserved between S. cerevisiae and mammals.
| S-EPMC85844 | biostudies-literature
Project description:Genetically encoded fluorescent cross-linking agents represent powerful tools useful both for visualising and modulating protein interactions in living cells. The far-red fluorescent protein HcRed, which is fluorescent only in a dimer form, can be used to promote the homo-dimerisation of target proteins, and thereby yield useful information about biological processes. We have in yeast cells expressed HcRed fused to a subunit of mitochondrial ATP synthase (mtATPase). This resulted in cross-linking of the large multi-subunit mtATPase complex within the inner-membrane of the mitochondrion. Fluorescence microscopy revealed aberrant mitochondrial morphology, and mtATPase complexes isolated from mitochondria were recovered as fluorescent dimers under conditions where complexes from control mitochondria were recovered as monomers. When viewed by electron microscopy normal cristae were absent from mitochondria in cells in which mATPase complexes were cross-linked. mtATPase dimers are believed to be the building blocks that are assembled into supramolecular mtATPase ribbons that promote the formation of mitochondrial cristae. We propose that HcRed cross-links mATPase complexes in the mitochondrial membrane hindering the normal assembly/disassembly of the supramolecular forms of mtATPase.
| S-EPMC3319629 | biostudies-literature
Project description:DNA damaging agents cause rapid shrinkage of tumors and form the basis of chemotherapy for sarcomas despite significant toxicities. Drugs having superior efficacy and wider therapeutic windows are needed to improve patient outcomes. We used cell proliferation and apoptosis assays in sarcoma cell lines and benign cells; γ-H2AX expression, comet assay, immunoblot analyses and drug combination studies in vitro and in patient derived xenograft (PDX) models. BO-1055 caused apoptosis and cell death in a concentration and time dependent manner in sarcoma cell lines. BO-1055 had potent activity (submicromolar IC50) against Ewing sarcoma and rhabdomyosarcoma, intermediate activity in DSRCT (IC50 = 2-3μM) and very weak activity in osteosarcoma (IC50 >10μM) cell lines. BO-1055 exhibited a wide therapeutic window compared to other DNA damaging drugs. BO-1055 induced more DNA double strand breaks and γH2AX expression in cancer cells compared to benign cells. BO-1055 showed inhibition of tumor growth in A673 xenografts and caused tumor regression in cyclophosphamide resistant patient-derived Ewing sarcoma xenografts and A204 xenografts. Combination of BO-1055 and irinotecan demonstrated synergism in Ewing sarcoma PDX models. Potent activity on sarcoma cells and its relative lack of toxicity presents a strong rationale for further development of BO-1055 as a therapeutic agent.
| S-EPMC5190008 | biostudies-literature