scholarly journals Synthesis of Novel Pyran Fragments to Incorporate into Peloruside Analogues

2021 ◽  
Author(s):  
◽  
Oliver Bayley

<p>Cancer is currently the second largest cause of death globally, leading to a high demand for new and effective chemotherapeutics. For years, natural products have been used as a source of new bioactive compounds; of particular interest in this context, as a source of new chemotherapeutics. One chemotherapeutic candidate which has attracted significant attention in synthetic and medicinal chemistry communities, is peloruside A. Peloruside A is a bioactive secondary metabolite isolated from the New Zealand marine sponge Mycale hentscheli. Since its discovery, peloruside A has shown great promise in cancer studies both in vivo and in vitro with effects observed even at nanomolar concentrations. These chemotherapeutic effects have been shown to occur by halting cell division at the G2/M checkpoint via microtubule stabilisation. Of particular interest is that this stabilisation occurs in a manner distinct from that of the already established taxane class of microtubule stabilising drugs. This means that peloruside A is able to offer both inhibition of cell division in Taxol® resistant cells and synergistic inhibition alongside the current taxane drugs. Since peloruside A is not abundantly available from its natural source, there is a strong incentive for the development of new synthetic strategies for peloruside A production. Unfortunately attempts at aquaculture and attempts at developing an industrial scale synthesis have both proven unsuccessful thus far. In an attempt to overcome some of the difficulties with the scale up of peloruside, analogues have been developed that are intended to have similar bioactivity to peloruside A but simpler, more concise, synthetic routes. These analogues will also enable further elucidation of the binding properties of peloruside A. This project focuses on the generation of a functionalised pyran fragment, starting from a simple carbohydrate, that may be incorporated into the proposed analogues.</p>

2021 ◽  
Author(s):  
◽  
Oliver Bayley

<p>Cancer is currently the second largest cause of death globally, leading to a high demand for new and effective chemotherapeutics. For years, natural products have been used as a source of new bioactive compounds; of particular interest in this context, as a source of new chemotherapeutics. One chemotherapeutic candidate which has attracted significant attention in synthetic and medicinal chemistry communities, is peloruside A. Peloruside A is a bioactive secondary metabolite isolated from the New Zealand marine sponge Mycale hentscheli. Since its discovery, peloruside A has shown great promise in cancer studies both in vivo and in vitro with effects observed even at nanomolar concentrations. These chemotherapeutic effects have been shown to occur by halting cell division at the G2/M checkpoint via microtubule stabilisation. Of particular interest is that this stabilisation occurs in a manner distinct from that of the already established taxane class of microtubule stabilising drugs. This means that peloruside A is able to offer both inhibition of cell division in Taxol® resistant cells and synergistic inhibition alongside the current taxane drugs. Since peloruside A is not abundantly available from its natural source, there is a strong incentive for the development of new synthetic strategies for peloruside A production. Unfortunately attempts at aquaculture and attempts at developing an industrial scale synthesis have both proven unsuccessful thus far. In an attempt to overcome some of the difficulties with the scale up of peloruside, analogues have been developed that are intended to have similar bioactivity to peloruside A but simpler, more concise, synthetic routes. These analogues will also enable further elucidation of the binding properties of peloruside A. This project focuses on the generation of a functionalised pyran fragment, starting from a simple carbohydrate, that may be incorporated into the proposed analogues.</p>


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhou Fang ◽  
Junjian Chen ◽  
Ye Zhu ◽  
Guansong Hu ◽  
Haoqian Xin ◽  
...  

AbstractPeptides are widely used for surface modification to develop improved implants, such as cell adhesion RGD peptide and antimicrobial peptide (AMP). However, it is a daunting challenge to identify an optimized condition with the two peptides showing their intended activities and the parameters for reaching such a condition. Herein, we develop a high-throughput strategy, preparing titanium (Ti) surfaces with a gradient in peptide density by click reaction as a platform, to screen the positions with desired functions. Such positions are corresponding to optimized molecular parameters (peptide densities/ratios) and associated preparation parameters (reaction times/reactant concentrations). These parameters are then extracted to prepare nongradient mono- and dual-peptide functionalized Ti surfaces with desired biocompatibility or/and antimicrobial activity in vitro and in vivo. We also demonstrate this strategy could be extended to other materials. Here, we show that the high-throughput versatile strategy holds great promise for rational design and preparation of functional biomaterial surfaces.


2014 ◽  
Vol 82 (7) ◽  
pp. 2890-2901 ◽  
Author(s):  
Marilena Gallotta ◽  
Giovanni Gancitano ◽  
Giampiero Pietrocola ◽  
Marirosa Mora ◽  
Alfredo Pezzicoli ◽  
...  

ABSTRACTGroup A streptococcus (GAS) is a human pathogen causing a wide repertoire of mild and severe diseases for which no vaccine is yet available. We recently reported the identification of three protein antigens that in combination conferred wide protection against GAS infection in mice. Here we focused our attention on the characterization of one of these three antigens, Spy0269, a highly conserved, surface-exposed, and immunogenic protein of unknown function. Deletion of thespy0269gene in a GAS M1 isolate resulted in very long bacterial chains, which is indicative of an impaired capacity of the knockout mutant to properly divide. Confocal microscopy and immunoprecipitation experiments demonstrated that the protein was mainly localized at the cell septum and could interactin vitrowith the cell division protein FtsZ, leading us to hypothesize that Spy0269 is a member of the GAS divisome machinery. Predicted structural domains and sequence homologies with known streptococcal adhesins suggested that this antigen could also play a role in mediating GAS interaction with host cells. This hypothesis was confirmed by showing that recombinant Spy0269 could bind to mammalian epithelial cellsin vitroand thatLactococcus lactisexpressing Spy0269 on its cell surface could adhere to mammalian cellsin vitroand to mice nasal mucosain vivo. On the basis of these data, we believe that Spy0269 is involved both in bacterial cell division and in adhesion to host cells and we propose to rename this multifunctional moonlighting protein as SpyAD (StreptococcuspyogenesAdhesion andDivision protein).


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Mohsin Khan ◽  
Suresh K Verma ◽  
Alexander R Mackie ◽  
Erin Vaughan ◽  
Srikanth Garikipati ◽  
...  

Rationale: Embryonic stem cells (ESCs) hold great promise for cardiac regeneration but are susceptible to ethical concerns, lack of autologous donors and teratoma formation. Recently, it has been observed that beneficial effects of stem cells are mediated by exosomes secreted out under various physiological conditions. ESCs have the ability to produce exosomes however their effect in the context of the heart is unknown. Objective: Determine the effect of ESC derived exosomes for cardiac repair and modulation of CPCs functions in the heart following myocardial infarction. Methods and Results: Exosomes were isolated from murine ESCs (mES Ex) or embryonic fibroblasts (MEFs) by ultracentrifugation and verified by Flotillin-1 immunoblot analysis. Induction of pluripotent markers, survival and in vitro tube formation was enhanced in target cells receiving ESC exosomes indicating therapeutic potential of mES Ex. mES Ex administration resulted in enhanced neovascularization, cardiomyocyte survival and reduced fibrosis post infarction consistent with resurgence of cardiac proliferative response. Importantly, mES Ex mediated considerable enhancement of cardiac progenitor cell (CPC) survival, proliferation and cardiac commitment concurrent with increased c-kit+ CPCs in vivo 4 weeks after mES Ex transfer. miRNA Array analysis of ESC and MEF exosomes revealed significantly high expression of miR290-295 cluster in the ESC exosomes compared to MEF exosomes. The underlying beneficial effect of mES Ex was tied to delivery of ESC miR-294 to the heart and in particular CPCs thereby promoting CPC survival and proliferation as analyzed by FACS based cell death analysis and CyQuant assay respectively. Interestingly, enhanced G1/S transition was observed in CPCs treated with miR-294 in conjunction with significant reduction of G1 phase. Conclusion: In conclusion, mES Ex provide a novel cell free system for cardiac regeneration with the ability to modulate both cardiomyocyte and CPC based repair programs in the heart thereby avoiding the risk of teratoma formation associated with ESCs.


RSC Advances ◽  
2018 ◽  
Vol 8 (57) ◽  
pp. 32440-32453 ◽  
Author(s):  
Kornphimol Kulthong ◽  
Loes Duivenvoorde ◽  
Barbara Z. Mizera ◽  
Deborah Rijkers ◽  
Guillaume ten Dam ◽  
...  

Novel microfluidic technologies allow the manufacture ofin vitroorgan-on-a-chip systems that hold great promise to adequately recapitulate the biophysical and functional complexity of organs foundin vivo.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Qiu-Lan Zhou ◽  
Zhi-Yi Chen ◽  
Yi-Xiang Wang ◽  
Feng Yang ◽  
Yan Lin ◽  
...  

With the development of nanotechnology, nanocarriers have been increasingly used for curative drug/gene delivery. Various nanocarriers are being introduced and assessed, such as polymer nanoparticles, liposomes, and micelles. As a novel theranostic system, nanocarriers hold great promise for ultrasound molecular imaging, targeted drug/gene delivery, and therapy. Nanocarriers, with the properties of smaller particle size, and long circulation time, would be advantageous in diagnostic and therapeutic applications. Nanocarriers can pass through blood capillary walls and cell membrane walls to deliver drugs. The mechanisms of interaction between ultrasound and nanocarriers are not clearly understood, which may be related to cavitation, mechanical effects, thermal effects, and so forth. These effects may induce transient membrane permeabilization (sonoporation) on a single cell level, cell death, and disruption of tissue structure, ensuring noninvasive, targeted, and efficient drug/gene delivery and therapy. The system has been used in various tissues and organs (in vitro or in vivo), including tumor tissues, kidney, cardiac, skeletal muscle, and vascular smooth muscle. In this review, we explore the research progress and application of ultrasound-mediated local drug/gene delivery with nanocarriers.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A185-A185
Author(s):  
Michelle Fleury ◽  
Derrick McCarthy ◽  
Holly Horton ◽  
Courtney Anderson ◽  
Amy Watt ◽  
...  

BackgroundAdoptive cell therapies have shown great promise in hematological malignancies but have yielded little progress in the context of solid tumors. We have developed T cell receptor fusion construct (TRuC®) T cells, which are equipped with an engineered T cell receptor that utilizes the full complement of TCR signaling subunits and recognizes tumor-associated antigens independent of HLA. In clinical trials, mesothelin (MSLN)-targeting TRuC-T cells (TC-210 or gavo-cel) have shown unprecedented results in patients suffering from advanced mesothelioma and ovarian cancer. To potentially increase the depth of response, we evaluated strategies that can promote intra-tumoral T cell persistence and function. Among the common ??-chain cytokines, IL-15 uniquely supports the differentiation and maintenance of memory T cell subsets by limiting terminal differentiation and conferring resistance to IL-2 mediated activation-induced cell death (AICD). In the studies described here, we evaluated the potential of IL-15 as an enhancement to TRuC-T cell phenotype, persistence and function against MSLN+ targets.MethodsPrimary human T cells were activated and transduced with a lentiviral vector encoding an anti-MSLN binder fused to CD3ε alone or co-expressed with a membrane-tethered IL-15rα/IL-15 fusion protein (IL-15fu). Transduced T cells were expanded for 9 days and characterized for expression of the TRuC, IL-15rα and memory phenotype before subjecting them to in vitro functional assays to evaluate cytotoxicity, cytokine production, and persistence. In vivo efficacy was evaluated in MHC class I/II deficient NSG mice bearing human mesothelioma xenografts.ResultsIn vitro, co-expression of the IL-15fu led to similar cytotoxicity and cytokine production as TC-210, but notably enhanced T-cell expansion and persistence upon repeated stimulation with MSLN+ cell lines. Furthermore, the IL-15fu-enhanced TRuC-T cells sustained a significantly higher TCF-1+ population and retained a stem-like phenotype following activation. Moreover, the IL-15fu-enhanced TRuCs demonstrated robust in vivo expansion and intra-tumoral accumulation as measured by ex vivo analysis of TRuC+ cells in the tumor and blood, with a preferential expansion of CD8+ T cells. Finally, IL-15fu-enhanced TRuC-T cells could be observed in the blood long after the tumors were cleared.ConclusionsThese pre-clinical studies suggest that the IL-15fu can synergize with TC-210 to increase the potency and durability of response in patients with MSLN+ tumors.Ethics ApprovalAll animal studies were approved by the respective Institutional Animal Care and Use Committees.


Author(s):  
Chuan Wang ◽  
Dan Ma ◽  
Yimin Hua ◽  
Hongyu Duan

AbstractBreast cancer resistance protein (BCRP/ABCG2) is a critical drug efflux transporters by limiting drugs’ transplacental transfer rates. More investigations on the regulation of placental BCRP offer great promise for enabling pronounced progress in individualized and safe pharmacotherapy during pregnancy. Histone deacetylases (HDACs) play an important role in epigenetic regulation of placental genes. It was reported recently by us that HDAC1 was involved in placental BCRP regulation in vitro. The aim of this study was to further explore the effect of HDAC1 on placental BCRP expression and functionality in animals. Randomly assigned C57BL pregnant dams received intraperitoneal injections of a negative control siRNA or Hdac1 siRNA from embryonic day 7.5 (E7.5) to E15.5, respectively. At E16.5, glyburide (GLB), a probe for evaluating placental BCRP efflux functionality, was injected via the tail vein. Animals were sacrificed through cervical dislocation at various times (5–180 min) after drug administration. The maternal blood, placentas, and fetal-units were collected. GLB concentrations were determined by a validated high-performance liquid chromatography/mass spectrometry (HPLC-MS) assay. Real-time quantitative PCR (qRT-PCR), Western blot, and immunohistochemical (IHC) analysis were employed to identify mRNA/protein levels and localization of gene expressions, respectively. It was noted that Hdac1 inhibition significantly decreased placental Bcrp expression, with markedly increases of GLB concentrations and area under the concentration-time curve (AUC) in fetal-units. Particularly, the ratios of fetal-unit/maternal plasma GLB concentrations were also significantly elevated following Hdac1 repression. Taken together, these findings suggested that HDAC1 was involved in positive regulation of placental BCRP expression and functionality in vivo.


2020 ◽  
Author(s):  
Shuang Qu ◽  
Zichen Jiao ◽  
Geng Lu ◽  
Bing Yao ◽  
Ting Wang ◽  
...  

ABSTRACTAlthough blockade of programmed death-ligand 1 (PD-L1) to enhance T cell immune responses shows great promise in tumor immunotherapy, the efficacy of such immune-checkpoint inhibition strategy is limited for patients with solid tumors. The mechanism underlying the limited efficacy of PD-L1 inhibitors remains unclear. Here, we show that human lung adenocarcinoma, regardless of PD-L1 protein positive or negative, all produce a long non-coding RNA isoform of PD-L1 (PD-L1-lnc) via alternative splicing, which promotes lung adenocarcinoma proliferation and metastasis. PD-L1-lnc in various lung adenocarcinoma cells is significantly upregulated by IFNγ in a manner similar to PD-L1 mRNA. Both in vitro and in vivo studies demonstrate that PD-L1-lnc increases proliferation and invasion but decreases apoptosis of lung adenocarcinoma cells. Mechanistically, PD-L1-lnc directly binds to c-Myc and enhances c-Myc transcriptional activity downstream in lung adenocarcinoma cells. Our results provide targeting PD-L1-lnc−c-Myc axis as a novel strategy for lung cancer therapy.


2007 ◽  
pp. 557-588 ◽  
Author(s):  
Kazuya Maeda ◽  
Yuichi Sugiyama
Keyword(s):  

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