Role of Intracellular and Extracellular Annexin A1 in MIA PaCa-2 Spheroids Formation and Drug Sensitivity

Simple Summary In order to improve the investigation of pancreatic cancer (PC), often supported through analyzes two-dimensional (2D) cell monolayers, we proposed to create a spheroid-based in vitro three-dimensional (3D) model using wild-type (WT) and ANXA1 knock-out (KO) MIA PaCa-2 PC cells. However, the production of spheroids still represents a technical challenge. Here, we have developed a protocol to obtain well-organized spheroids and have proved that Annexin A1 (ANXA1) affects the spheroid formation, because the WT cells have a greater ability to form this 3D model when compared to the ANXA1 KO examples. We also investigated how ANXA1 action could influence the PC pharmacological response both in basal conditions and by mimicking a tumor system through the addition of autocrine EVs. ANXA1, via EVs, significantly improves the formation, the stability and the drug resistance of this model, particularly compared to the ANXA1 KO one, which shows a structural instability and a greater drug sensitivity. Among solid tumors, pancreatic cancer (PC) remains a leading cause of death. In PC, the protein ANXA1 has been identified as an oncogenic factor acting in an autocrine/paracrine way, and also as a component of tumor-deriving extracellular vesicles. Here, we proposed the experimental protocol to obtain spheroids from the two cell lines, wild-type (WT) and Annexin A1 (ANXA1) knock-out (KO) MIA PaCa-2, this last previously obtained through CRISPR/Cas9 genome editing system. The use of three-dimensional (3D) models, like spheroids, can be useful to mimic tumor characteristics and for preclinical chemo-sensitivity studies. By using PC spheroids, we have assessed the activity of intracellular and extracellular ANXA1. Indeed, we have proved that the intracellular protein influences in vitro tumor development and growth by spheroids analysis, in addition to defining the modification about cell protein pattern in ANXA1 KO model compared to the WT one. Moreover, we have tested the response to FOLFIRINOX chemotherapy regimen whose cytostatic effect appeared notably increased in ANXA1 KO spheroids. Additionally, this study has highlighted that the extracellular ANXA1 action is strengthened through the EVs supporting spheroids growth and resistance to drug treatment, mainly affecting tumor progression. Thus, our data interestingly suggest the relevance of ANXA1 as a potential therapeutic PC marker

Discovering the Biological Target of 5-epi-Sinuleptolide Using a Combination of Proteomic Approaches

Sinuleptolide and its congeners are diterpenes with a norcembranoid skeleton isolated from the soft coral genus Sinularia. These marine metabolites are endowed with relevant biological activities, mainly associated with cancer development. 5-epi-sinuleptolide has been selected as a candidate for target discovery studies through the application of complementary proteomic approaches. Specifically, a combination of conventional chemical proteomics based on affinity chromatography, coupled with high-resolution mass spectrometry and bioinformatics, as well as drug affinity responsive target stability (DARTS), led to a clear identification of actins as main targets for 5-epi-sinuleptolide. Subsequent in-cell assays, performed with cytochalasin D as reference compound, gave information on the ability of 5-epi-sinuleptolide to disrupt the actin cytoskeleton by loss of actin fibers and formation of F-actin amorphous aggregates. These results suggest the potential application of 5-epi-sinuleptolide as a useful tool in the study of the molecular processes impaired in several disorders in which actin is thought to play an essential role

Targeting USP-7 by a Novel Fluorinated 5-Pyrazolyl-Urea Derivative

: The impact of innovative technologies on the target discovery has been employed here to characterize the interactome of STIRUR 41, a promising 3-fluoro-phenyl-5-pyrazolyl-urea derivative endowed with anti-cancer activity, on neuroblastoma-related cells. A drug affinity responsive target stability-based proteomic platform has been optimized to elucidate the molecular mechanism at the basis of STIRUR 41 action, together with immunoblotting analysis and in silico molecular docking. Ubiquitin Specific Protease 7 (USP-7), one of the deubiquitinating enzymes which protect substrate proteins from proteasomal degradation, has been identified as the most affine STIRUR 41 target. As further demonstrated by in vitro and in-cell assays, STIRUR 41 was able to inhibit both the enzymatic activity of USP-7 and its expression levels in neuroblastoma-related cells, thus laying an encouraging base for the blockade of USP-7 downstream signaling

Discovering the Biological Target of 5-epi-Sinuleptolide Using a Combination of Proteomic Approaches

Sinuleptolide and its congeners are diterpenes with a norcembranoid skeleton isolated from the soft coral genus Sinularia. These marine metabolites are endowed with relevant biological activities, mainly associated with cancer development. 5-epi-sinuleptolide has been selected as a candidate for target discovery studies through the application of complementary proteomic approaches. Specifically, a combination of conventional chemical proteomics based on affinity chromatography, coupled with high-resolution mass spectrometry and bioinformatics, as well as drug affinity responsive target stability (DARTS), led to a clear identification of actins as main targets for 5-epi-sinuleptolide. Subsequent in-cell assays, performed with cytochalasin D as reference compound, gave information on the ability of 5-epi-sinuleptolide to disrupt the actin cytoskeleton by loss of actin fibers and formation of F-actin amorphous aggregates. These results suggest the potential application of 5-epi-sinuleptolide as a useful tool in the study of the molecular processes impaired in several disorders in which actin is thought to play an essential role

A multidisciplinary functional proteomics-aided strategy as a tool for the profiling of a novel cytotoxic thiadiazolopyrimidone

: In recent years, thiadiazolopyrimidine derivatives have been acknowledged for their striking poly-pharmacological framework, thus representing an interesting scaffold for the development of new therapeutic candidates. This paper examines the synthesis and the interactome characterization of a novel bioactive thiadiazolopyrimidone (compound 1), endowed with cytotoxic activity on HeLa cancer cells. In detail, starting from a small set of synthesized thiadiazolopyrimidones, a multi-disciplinary strategy has been carried out on the most bioactive one to disclose its potential biological targets by functional proteomics, using a label-free mass spectrometry based platform coupling Drug Affinity Responsive Target Stability and targeted Limited Proteolysis-Multiple Reaction Monitoring. The identification of Annexin A6 (ANXA6) as compound 1 most reliable cellular partner paved the way to deepen the protein-ligand interaction through bio-orthogonal approaches and to prove compound 1 action on migration and invasion processes governed by ANXA6 modulation. The identification of compund 1 as the first ANXA6 protein modulator represents a relevant tool to further explore the biological role of ANXA6 in cancer, as well as to develop novel anticancer candidates

The Pyrazolyl-Urea Gege3 Inhibits the Activity of ANXA1 in the Angiogenesis Induced by the Pancreatic Cancer Derived EVs

The pyrazolyl-urea Gege3 molecule has shown interesting antiangiogenic effects in the tumor contest. Here, we have studied the role of this compound as interfering with endothelial cells activation in response to the paracrine effects of annexin A1 (ANXA1), known to be involved in promoting tumor progression. ANXA1 has been analyzed in the extracellular environment once secreted through microvesicles (EVs) by pancreatic cancer (PC) cells. Particularly, Gege3 has been able to notably prevent the effects of Ac2-26, the ANXA1 mimetic peptide, and of PC-derived EVs on endothelial cells motility, angiogenesis, and calcium release. Furthermore, this compound also inhibited the translocation of ANXA1 to the plasma membrane, otherwise induced by the same ANXA1-dependent extracellular stimuli. Moreover, these effects have been mediated by the indirect inhibition of protein kinase C\u3b1 (PKC\u3b1), which generally promotes the phosphorylation of ANXA1 on serine 27. Indeed, by the subtraction of intracellular calcium levels, the pathway triggered by PKC\u3b1 underwent a strong inhibition leading to the following impediment to the ANXA1 localization at the plasma membrane, as revealed by confocal and cytofluorimetry analysis. Thus, Gege3 appeared an attractive molecule able to prevent the paracrine effects of PC cells deriving ANXA1 in the tumor microenvironment

Label-Free Quantitative Proteomics to Explore the Action Mechanism of the Pharmaceutical-Grade Triticum vulgare Extract in Speeding Up Keratinocyte Healing

Plant extracts have shown beneficial properties in terms of skin repair, promoting wound healing through a plethora of mechanisms. In particular, the poly-/oligosaccharidic aqueous extract of Triticum vulgare (TVE), as well as TVE-based products, shows interesting biological assets, hastening wound repair. Indeed, TVE acts in the treatment of tissue regeneration mainly on decubitus and venous leg ulcers. Moreover, on scratched monolayers, TVE prompts HaCat cell migration, correctly modulating the expression of metalloproteases toward a physiological matrix remodeling. Here, using the same HaCat-based in vitro scratch model, the TVE effect has been investigated thanks to an LFQ proteomic analysis of HaCat secretomes and immunoblotting. Indeed, the unbiased TVE effect on secreted proteins has not yet been fully understood, and it could be helpful to obtain a comprehensive picture of its bio-pharmacological profile. It has emerged that TVE treatment induces significant up-regulation of several proteins in the secretome (153 to be exact) whereas only a few were down-regulated (72 to be exact). Interestingly, many of the up-regulated proteins are implicated in promoting wound-healing-related processes, such as modulating cell–cell interaction and communication, cell proliferation and differentiation, and prompting cell adhesion and migration

Synthesis, functional proteomics and biological evaluation of new 5-pyrazolyl ureas as potential anti-angiogenic compounds

Based on biological results of previous synthesized pyrazolyl ureas able to interfere with angiogenesis process, we planned and synthesized the new benzyl-urea derivatives 2-4; some of them showed an interesting anti-proliferative profile and particularly 4e potently inhibited HUVEC proliferation. To shed light on the mechanism of action of 4e, its interactome has been deeply inspected to identify the most prominent protein partners, mainly taking into account kinome and phosphatome, through drug affinity responsive target stability experiments, followed by targeted limited proteolysis analysis. From these studies, PP1\u3b3 emerged as the most reliable 4e potential target in HUVEC. Molecular docking simulations on PP1\u3b3 were carried out to predict 4e binding mode. To assess its potential anti-angiogenic effect, 4e was tested in vitro to verify interference on kinase and phosphate activities. Overall, our results evidenced for 4e an interesting anti-angiogenic action, probably due to its action at intracellular level on PP1\u3b3 signalling pathways