tretazicar (CB1954) / J&J - LARVOL DELTA

Novel TdsD nitroreductase: characterization of kinetics and substrate specificity. (PubMed, Biotechnol Lett) - "It also possesses similar specificity for nitroaromatic compounds and quinones, in particular the shared characteristic of being especially active with 2-hydroxy-1,4-naphthoquinone derivatives. It is possible that the similar character of binding of oxidants and other ligands relative to the NfsA and NfsB subfamily enzymes may be related to the conserved Arg27 and Ser53 residues in the active site of TdsD1."

Journal

Structural Evaluation of a Nitroreductase Engineered for Improved Activation of the 5-Nitroimidazole PET Probe SN33623. (PubMed, Int J Mol Sci) - "Additionally, computational modeling of SN33623, CB1954, and metronidazole binding in the active sites of both the mutant and wild-type enzymes revealed key differences in substrate orientations and interactions, with improvements in activity being mirrored by reduced distances between the N5-H of isoalloxazine and the substrate nitro group oxygen in the mutant models. These findings deepen our understanding of nitroreductase substrate specificity and catalytic mechanisms and have potential implications for developing more effective theranostic imaging strategies in cancer treatment."

Journal • Gene Therapies • Oncology

Fluorogenic multi-input/-output Biomolecular AND logic gate as a platform for imaging the successful delivery & Exression of nitroreductase-based transgenes under normoxia for suicide gene therapies (ACS-Sp 2024) - "One DEPT modality for mediating SGT is the canonical G-/V-DEPT nitroreductase (NTR)-CB1954 system, which uses E. coli-derived nfsB transgene and a nitroaromatic-containing prodrug...Thus, we've developed an irreversibly-activatable latent fluorogenic reporter that operates in the form of a multi-input/-output molecular AND logic gate that displays a manifold fluorescence intensity enhancement upon activation, which operates through a concerted (i) intramolecular inhibition of an a-PeT quenching mechanism and (ii) unrestricting of an ICT process in restricted form, whereby both are triggered by exploiting Type I NTR bioreductive activity. The technology offers application towards (i) the direct visualization/confirmation of successful SGT-based transgenic NTR delivery and translational bioactivity that ultimately ensues, wherein at any point any of such could pose a functional error that affects nitroaromatic-based prodrug conversion efficiency/efficacy; and (ii)..."

Gene therapy • Gene Therapies • Oncology

Visualizing successful gene-/viral-directed enzyme prodrug-mediated nitroreductase-encoding transgene vector expression & bioactivity (ACS-Sp 2024) - "One such representative system affording SGT is the nitroreductase (NTR)-CB1954 combination, which is mediated by a G-/V-DEPT approach (typically via using a viral vector), whereby the E. coli NTR gene (nfsB) gets exploited because it encodes a bioorthogonal oxygen-insensitive NAD(P)H cofactor-preferred enzyme that activates CB1954 and other nitroaromatic moiety-based prodrugs to generate potent interstrand DNA cross-links that induce apoptosis in both proliferating/quiescent cells...To surmount such, we have developed a caged reporter affording visualization of such processes via capitalizing on upregulated NTR activity when under hypoxic conditions. The OFF-ON near-infrared (NIR) fluorescent construct is an a-PeT-regulated smart probe bearing a directly-linked pendant nitroaromatic moiety that provides 12-fold enhancement in its fluorescence emission at 720 nm in solutio/in vitro in response to elevated NTR activity in brain cancer cells."

Brain Cancer • Oncology • Solid Tumor

Latent reporter for bioimaging select heterologous haloenzyme activity borne out of metastatic brain cancer suicide gene therapy (SGT) administration via capitalizing on a triggerable multimechanistic-mediated modulation of its tuned energetics (ACS-Fall 2023) - "As cancers have cell-type specific promoters, catalysis can be predisposed to occur in only such tissue.One DEPT modality for mediating SGT is the canonical G-/V-DEPT nitroreductase (NTR)-CB1954 system, which uses E. coli-derived nfsB transgene and a nitroaromatic-containing prodrug...To overcome such drawbacks, we exploit condition-restrictive oxics to provide for the first latent reporter responding to only Type I NTR activity in brain cancer cells upon NsfB haloenzyme presentation via it catalyzing a multimechanistic-mediated modulation to its aptly-tuned energetics under normoxic conditions. The latent reporter displays a manifold fluorescence enhancement in the NIR-I spectral region, thereby having application towards directly confirming (i) nsfB delivery via its presentation, (ii) prodrug activation, and (ii) allowing for its NIRF image-guided surgical removal."

Gene therapy • Metastases • Brain Cancer • Gene Therapies • Oncology • Solid Tumor

The Crystal Structure of Engineered Nitroreductase NTR 2.0 and Impact of F70A and F108Y Substitutions on Substrate Specificity. (PubMed, Int J Mol Sci) - "We additionally present a survey of reductive activity with eight alternative nitroaromatic substrates, to provide access to alternative ablation prodrugs, and explore applications such as remediation of dinitrotoluene pollutants. The predicted binding modes of four key substrates were investigated using molecular modelling."

Journal

Structure and Dynamics of Three Escherichia coli NfsB Nitro-Reductase Mutants Selected for Enhanced Activity with the Cancer Prodrug CB1954. (PubMed, Int J Mol Sci) - "The most active one contains T41Q/N71S/F124T/M127V, in which the additional M127V mutation enlarges a small channel to the active site. Molecular dynamics simulations show that the mutations or reduction of the FMN cofactors of the protein has little effect on its dynamics and that the largest backbone fluctuations occur at residues that flank the active site, contributing towards its broad substrate range."

Journal • Gene Therapies • Oncology

Inhaled Gold Nano-star Carriers for Targeted Delivery of Triple Suicide Gene Therapy and Therapeutic MicroRNAs to Lung Metastases: Development and Validation in a Small Animal Model. (PubMed, Adv Ther (Weinh)) - "The intranasal delivery of uPA-AuNS-TK-p53-NTR-microRNAs NPs (pAuNS@TK-p53-NTR-miRs) in mice predominantly accumulated in lungs and facilitated ganciclovir and CB1954 prodrug-mediated gene therapy against TNBC lung metastases. This new nanosystem may serve as an adaptable-across-cancer-type, facile, and clinically scalable platform to allow future inhalational suicide gene-miR combination therapy for patients harboring pulmonary metastases."

Journal • Preclinical • Breast Cancer • Gene Therapies • Lung Cancer • Oncology • Solid Tumor • Triple Negative Breast Cancer • MIR100

The 3D-structure, kinetics and dynamics of the E. coli nitroreductase NfsA with NADP provide glimpses of its catalytic mechanism. (PubMed, FEBS Lett) - "The nicotinamide ring and nicotinamide ribose are mobile, as confirmed in molecular dynamics (MD) simulations. We present a model of NADPH bound to NfsA. Only one NADP is seen bound to the NfsA dimers, and MD simulations show that binding of a second NADP(H) cofactor is unfavourable, suggesting that NfsA and other members of this protein superfamily may have a half-of-sites mechanism."

Journal • Oncology

The Unusual Cosubstrate Specificity of NQO2: Conservation Throughout the Amniotes and Implications for Cellular Function. (PubMed, Front Pharmacol) - "These NQO2 knockouts along with the parental cells were used to demonstrate that cellular NQO2 is unable to catalyze the activation of the DNA cross-linking reagent, CB1954, without the addition of exogenous dihydronicotinamide riboside (NRH). Therefore, the unusual cosubstrate preference of NQO2 appears to be conserved throughout the amniotes; however, we found that NQO2 is not well-conserved in the amphibians. A phylogenetic analysis indicates that NQO1 and NQO2 diverged at the time, approximately 450 MYA, when tetrapods were beginning to evolve."

Journal • NQO1

Caged optical reporter for visualizing nitroreductase suicide gene therapy delivery (ACS-Sp 2022) - "As malignant tumor cell-specific promoters control gene expression, the enzyme can be preferentially predisposed to such.One GDEPT system that is an attractive approach is the nitroreductase (NTR)-CB1954 combination...The OFF-ON near-infrared (NIR) fluorescent construct is a d-PeT-regulated nitroaromatic-appended smart probe that provided 8-fold fluorescence enhancement at 720 nm in solutio/in vitro under normoxic conditions upon application to glioblastoma U87 cell line, of which upregulated NTR expression was established ex vitro via labeling surrogate biomarker carbonic anhydrase IX (CAIX). The ability to potentially afford the visualization of nfsB-transduced malignant tumor cells in vivo (here via mimicking upregulated NTR expression) paves the way for their fluorescence-guided resection in the clinic."

Brain Cancer • Gene Therapies • Glioblastoma • Oncology • Solid Tumor • CA9