AD0157, a pyrrolidinedione fungal metabolite, inhibits angiogenesis by targeting the Akt signaling pathway

In the course of a screening program for the inhibitors of angiogenesis from marine sources, AD0157, a pyrrolidinedione fungal metabolite, was selected for its angiosupressive properties. AD0157 inhibited the growth of endothelial and tumor cells in culture in the micromolar range. Our results show that subtoxic doses of this compound inhibit certain functions of endothelial cells, namely, differentiation, migration and proteolytic capability. Inhibition of the mentioned essential steps of in vitro angiogenesis is in agreement with the observed antiangiogenic activity, substantiated by using two in vivo angiogenesis models, the chorioallantoic membrane and the zebrafish embryo neovascularization assays, and by the ex vivo mouse aortic ring assay. Our data indicate that AD0157 induces apoptosis in endothelial cells through chromatin condensation, DNA fragmentation, increases in the subG1 peak and caspase activation. The data shown here altogether indicate for the first time that AD0157 displays antiangiogenic effects, both in vitro and in vivo, that are exerted partly by targeting the Akt signaling pathway in activated endothelial cells. The fact that these effects are carried out at lower concentrations than those required for other inhibitors of angiogenesis makes AD0157 a new promising drug candidate for further evaluation in the treatment of cancer and other angiogenesis-related pathologies. [Our experimental work is supported by grant P12-CTS-1507 (Andalusian Government and FEDER) and funds from group BIO-267 (Andalusian Government). The "CIBER de Enfermedades Raras" is an initiative from the ISCIII (Spain). This communication has the support of a travel grant "Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech"].Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

PKD phosphorylation and COP9/Signalosome modulate intracellular Spry2 protein stability

Spry2 is a molecular modulator of tyrosine kinase receptor signaling pathways that has cancer-type-specific effects. Mammalian Spry2 protein undergoes tyrosine and serine phosphorylation in response to growth factor stimulation. Spry2 expression is distinctly altered in various cancer types. Inhibition of the proteasome functionality results in reduced intracellular Spry2 degradation. Using in vitro and in vivo assays, we show that protein kinase D (PKD) phosphorylates Spry2 at serine 112 and interacts in vivo with the C-terminal half of this protein. Importantly, missense mutation of Ser112 decreases the rate of Spry2 intracellular protein degradation. Either knocking down the expression of all three mammalian PKD isoforms or blocking their kinase activity with a specific inhibitor contributes to the stabilization of Spry2 wild-type protein. Downregulation of CSN3, a component of the COP9/Signalosome that binds PKD, significantly increases the half-life of Spry2 wild-type protein but does not affect the stability of a Spry2 after mutating Ser112 to the non-phosphorylatable residue alanine. Our data demonstrate that both PKD and the COP9/Signalosome play a significant role in control of Spry2 intracellular stability and support the consideration of the PKD/COP9 complex as a potential therapeutic target in tumors where Spry2 expression is reduced.JMR-C received grant support from MINECO-FEDER (SAF2016-78852-R), AESI-ISCIII (PI20CIII/00029) and Spanish Association against Cancer (AECC, CGB14143035THOM). ES group was supported by grants from ISCIII-MCUI (FIS PI19/00934), JCyL (SA264P18-UIC-076), Areces Foundation (CIVP19A5942), Solorzano-Barruso Foundation (FS/32–2020) and by ISCIII-CIBERONC (group CB16/12/00352). Funding to AM group was provided by the Agencia Estatal de Investigación (PID2019-104867RB-I00/AEI/10.13039/501100011033) and by ISCIII-CIBERONC (group CB16/12/00273). TI was supported by grant PID2020-115218RB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe” and by ISCIII-CIBERNED. RB received grant support from AESI-ISCIII (PI20CIII/00019). Finally, DP-J and MY groups were supported by grants 1.012.022 (to DP-J), 1.010.929 and 1.400.002 (both to MY) from Fundación Universidad Alfonso X el Sabio (FUAX). All research co-financed by FEDER funds.S

Anthraquinones as inhibitors of SOS RAS-GEF activity

© 2021 by the authors.Recent breakthroughs have reignited interest in RAS GEFs as direct therapeutic targets. To search for new inhibitors of SOS GEF activity, a repository of known/approved compounds (NIH-NACTS) and a library of new marine compounds (Biomar Microbial Technologies) were screened by means of in vitro RAS-GEF assays using purified, bacterially expressed SOS and RAS constructs. Interestingly, all inhibitors identified in our screenings (two per library) shared related chemical structures belonging to the anthraquinone family of compounds. All our anthraquinone SOS inhibitors were active against the three canonical RAS isoforms when tested in our SOS GEF assays, inhibited RAS activation in mouse embryonic fibroblasts, and were also able to inhibit the growth of different cancer cell lines harboring WT or mutant RAS genes. In contrast to the commercially available anthraquinone inhibitors, our new marine anthraquinone inhibitors did not show in vivo cardiotoxicity, thus providing a lead for future discovery of stronger, clinically useful anthraquinone SOS GEF blockers.Work supported by grants from ISCIII-MCIU (PI19/00934; CIBERONC-CB16/12/00352), JCyL (SA264P18-UIC 076) and Foundations Ramón Areces (CIVP19A5942, Madrid) and Samuel Solórzano (FS/22-2019, USAL). R.F.M. was supported by a predoctoral fellowship from Consejería de Educación, JCyL. Research co-financed by FEDER funds

The Marine Fungal Metabolite, AD0157, Inhibits Angiogenesis by Targeting the Akt Signaling Pathway

In the course of a screening program for the inhibitors of angiogenesis from marine sources, AD0157, a pyrrolidinedione fungal metabolite, was selected for its angiosupressive properties. AD0157 inhibited the growth of endothelial and tumor cells in culture in the micromolar range. Our results show that subtoxic doses of this compound inhibit certain functions of endothelial cells, namely, differentiation, migration and proteolytic capability. Inhibition of the mentioned essential steps of in vitro angiogenesis is in agreement with the observed antiangiogenic activity, substantiated by using two in vivo angiogenesis models, the chorioallantoic membrane and the zebrafish embryo neovascularization assays, and by the ex vivo mouse aortic ring assay. Our data indicate that AD0157 induces apoptosis in endothelial cells through chromatin condensation, DNA fragmentation, increases in the subG1 peak and caspase activation. The data shown here altogether indicate for the first time that AD0157 displays antiangiogenic effects, both in vitro and in vivo, that are exerted partly by targeting the Akt signaling pathway in activated endothelial cells. The fact that these effects are carried out at lower concentrations than those required for other inhibitors of angiogenesis makes AD0157 a new promising drug candidate for further evaluation in the treatment of cancer and other angiogenesis-related pathologies

Induction of New Aromatic Polyketides from the Marine Actinobacterium Streptomyces griseorubiginosus through an OSMAC Approach

Using the OSMAC (One Strain Many Compounds) approach, the actinobacterium Streptomyces griseorubiginosus, derived from an unidentified cnidarian collected from a reef near Pointe de Bellevue in Réunion Island (France), was subjected to cultivation under diverse conditions. This endeavour yielded the isolation of a repertoire of 23 secondary metabolites (1–23), wherein five compounds were unprecedented as natural products (19–23). Specifically, compounds 19 and 20 showcased novel anthrone backbones, while compound 23 displayed a distinctive tetralone structure. Additionally, compounds 21 and 22 presented an unusual naphtho [2,3-c]furan-4(9H)-one chromophore. Interestingly, the detection of all these novel compounds (19–23) was exclusively achieved when the bacterium was cultured in FA-1 liquid medium supplemented with the epigenetic modifier γ-butyrolactone. The elucidation of the structural features of the newfound compounds was accomplished through a combination of HRESIMS, 1D and 2D NMR spectroscopy, as well as QM-NMR (Quantum Mechanical—Nuclear Magnetic Resonance) methods and by comparison with existing literature. Moreover, the determination of the relative configuration of compound 23 was facilitated by employing the mix-J-DP4 computational approach

OSMAC Approach and Cocultivation for the Induction of Secondary Metabolism of the Fungus Pleotrichocladium opacum

The application of an OSMAC (One Strain–Many Compounds) approach on the fungus Pleotrichocladium opacum, isolated from a soil sample collected on the coast of Asturias (Spain), using different culture media, chemical elicitors, and cocultivation techniques resulted in the isolation and identification of nine new compounds (8, 9, 12, 15–18, 20, 21), along with 15 known ones (1–7, 10, 11, 14, 19, 22–25). Compounds 1–9 were detected in fungal extracts from JSA liquid fermentation, compounds 10–12 were isolated from a solid rice medium, whereas compounds 14 and 15 were isolated from a solid wheat medium. Addition of 5-azacytidine to the solid rice medium caused the accumulation of compounds 16–18, whereas adding N-acetyl-d-glucosamine triggered the production of two additional metabolites, 19 and 20. Finally, cocultivation of the fungus Pleotrichocladium opacum with Echinocatena sp. in a solid PDA medium led to the production of five additional natural products, 21–25. The structures of the new compounds were elucidated by HRESIMS and 1D and 2D NMR as well as by comparison with literature data. DP4+ and mix-J-DP4 computational methods were applied to determine the relative configurations of the novel compounds, and in some cases, the absolute configurations were assigned by a comparison of the optical rotations with those of related natural products.This research was funded by the Ministerio de Ciencia, Innovación y Universidades (DIN2018-009716A24330292) of the Spanish Government; Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI-FEDER) ProID2021010118; and Fondo Social Europeo (Programa Operativo Integrado de Canarias FSE 2014–2020, Eje 3, Tema Prioritario 74–85%). Víctor Rodríguez Martín-Aragón thanks the Ministerio de Ciencia e Innovación (MICINN) of the Spanish Government for the financial support (State Plan for Scientific and Technical Research and Innovation 2021–2023) for a predoctoral fellowship. C. Cuadrado thanks the Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI) and Fondo Social Europeo (Programa Operativo Integrado de Canarias FSE 2014–2020, Eje 3, Tema Prioritario 74–85%) for a predoctoral fellowship. This study made use of Galicia Supercomputing Center (CESGA) facilities as provided by CSIC. The authors also wish to thank Prof. Joaquin Altarejos from the University of Jaen, Spain, for measuring optical rotations of the isolated compounds.Peer reviewe