Tumour cell blebbing and extracellular vesicle shedding: key role of matrikines and ribosomal protein SA

Distinct roles of protrusions and collagen deformation in collective invasion of cancer cell types

The breast tumor microenvironment is composed of heterogeneous cell populations, including normal epithelial cells, cancer-associated fibroblasts (CAFs), and tumor cells that lead collective cell invasion. Both leader tumor cells and CAFs are known to play important roles in tumor invasion across the collagen-rich stromal boundary. However, their individual abilities to utilize their cell-intrinsic protrusions and perform force-based collagen remodeling to collectively invade remain unclear. To compare collective invasion phenotypes of leader-like tumor cells and CAFs, we embedded spheroids composed of 4T1 tumor cells or mouse tumor-derived CAF cell lines within 3D collagen gels and analyzed their invasion and collagen deformation. We found that 4T1s undergo greater invasion while generating lower collagen deformation compared with CAFs. Although force-driven collagen deformations are conventionally associated with higher cellular forces and invasion, here 4T1s specifically rely on actin-based protrusions, while CAFs rely on myosin-based contractility for collective invasion. In denser collagen, both cell types slowed their invasion, and selective pharmacological inhibitions show that Arp2/3 is required but myosin-II is dispensable for 4T1 invasion. Furthermore, depletion of CDH3 from 4T1s and DDR2 from CAFs reduces their ability to distinguish between collagen densities. For effective invasion, both cell types reorient and redistribute magnetically prealigned collagen fibers. With heterogeneous cell populations of cocultured CAFs and 4T1s, higher percentage of CAFs impeded invasion while increasing collagen fiber alignment. Overall, our findings demonstrate distinctive mechanisms of collective invasion adopted by 4T1 tumor cells and CAFs, one relying more on protrusions and the other on force-based collagen deformation. These results suggest that individually targeting cellular protrusions or contractility may not be universally applicable for all cell types or collagen densities, and a better cell-type-dependent approach could enhance effectiveness of cancer therapies.

The Influence of Extra-Ribosomal Functions of Eukaryotic Ribosomal Proteins on Viral Infection

The eukaryotic ribosome is a large ribonucleoprotein complex consisting of four types of ribosomal RNA (rRNA) and approximately 80 ribosomal proteins (RPs), forming the 40S and 60S subunits. In all living cells, its primary function is to produce proteins by converting messenger RNA (mRNA) into polypeptides. In addition to their canonical role in protein synthesis, RPs are crucial in controlling vital cellular processes such as cell cycle progression, cellular proliferation, differentiation, DNA damage repair, genome structure maintenance, and the cellular stress response. Viruses, as obligate intracellular parasites, depend completely on the machinery of the host cell for their replication and survival. During viral infection, RPs have been demonstrated to perform a variety of extra-ribosomal activities, which are especially important in viral disease processes. These functions cover a wide range of activities, ranging from controlling inflammatory responses and antiviral immunity to promoting viral replication and increasing viral pathogenicity. Deciphering the regulatory mechanisms used by RPs in response to viral infections has greatly expanded our understanding of their functions outside of the ribosome. Furthermore, these findings highlight the promising role of RPs as targets for the advancement of antiviral therapies and the development of novel antiviral approaches. This review comprehensively examines the many functions of RPs outside of the ribosome during viral infections and provides a foundation for future research on the host-virus interaction.

The dual role of ribosomal protein SA in pathogen infection: the key role of structure and localization

Ribosomal protein SA (RPSA) plays multiple roles in cells, including ribosomal biogenesis and translation, cellular migration, and cytoskeleton reorganization. RPSA is crucial in the process of pathogen infection. Extensive research has examined RPSA's role in pathogen adhesion and invasion, but its broader functions, particularly its anti-infective capabilities, have garnered increasing attention in recent years. This dual role is closely related to its structural domains, which influence its localization and function. This review summarizes key research findings concerning the functional domains of RPSA and analyzes the relationship between its membrane localization and structural domains. Additionally, the functional implications of RPSA are categorized based on its different localizations during pathogen infection. Specifically, when RPSA is located on the cell surface, it promotes pathogen adhesion and invasion of host cells; conversely, when RPSA is located intracellularly, it exhibits anti-infective properties. Overall, RPSA shows a dual nature, both in facilitating pathogen invasion of the host and in possessing the ability to resist pathogen infection. This review comprehensively examines the dual role of RPSA in pathogen infection by analyzing its structural domains, localization, and interactions with cellular and pathogen molecules. Our aim is to update and deepen researchers' understanding of the various functions of RPSA during pathogen infection.

Beyond Blood Clotting: The Many Roles of Platelet-Derived Extracellular Vesicles

Platelet-derived extracellular vesicles (pEVs) are emerging as pivotal players in numerous physiological and pathological processes, extending beyond their traditional roles in hemostasis and thrombosis. As one of the most abundant vesicle types in human blood, pEVs transport a diverse array of bioactive molecules, including growth factors, cytokines, and clotting factors, facilitating crucial intercellular communication, immune regulation, and tissue healing. The unique ability of pEVs to traverse tissue barriers and their biocompatibility position them as promising candidates for targeted drug delivery and regenerative medicine applications. Recent studies have underscored their involvement in cancer progression, viral infections, wound healing, osteoarthritis, sepsis, cardiovascular diseases, rheumatoid arthritis, and atherothrombosis. For instance, pEVs promote tumor progression and metastasis, enhance tissue repair, and contribute to thrombo-inflammation in diseases such as COVID-19. Despite their potential, challenges remain, including the need for standardized isolation techniques and a comprehensive understanding of their mechanisms of action. Current research efforts are focused on leveraging pEVs for innovative anti-cancer treatments, advanced drug delivery systems, regenerative therapies, and as biomarkers for disease diagnosis and monitoring. This review highlights the necessity of overcoming technical hurdles, refining isolation methods, and establishing standardized protocols to fully unlock the therapeutic potential of pEVs. By understanding the diverse functions and applications of pEVs, we can advance their use in clinical settings, ultimately revolutionizing treatment strategies across various medical fields and improving patient outcomes.

Matrikines in the skin: Origin, effects, and therapeutic potential

The extracellular matrix (ECM) represents a complex multi-component environment that has a decisive influence on the biomechanical properties of tissues and organs. Depending on the tissue, ECM components are subject to a homeostasis of synthesis and degradation, a subtle interplay that is influenced by external factors and the intrinsic aging process and is often disturbed in pathologies. Upon proteolytic cleavage of ECM proteins, small bioactive peptides termed matrikines can be formed. These bioactive peptides play a crucial role in cell signaling and contribute to the dynamic regulation of both physiological and pathological processes such as tissue remodeling and repair as well as inflammatory responses. In the skin, matrikines exert an influence for instance on cell adhesion, migration, and proliferation as well as vasodilation, angiogenesis and protein expression. Due to their manifold functions, matrikines represent promising leads for developing new therapeutic options for the treatment of skin diseases. This review article gives a comprehensive overview on matrikines in the skin, including their origin in the dermal ECM, their biological effects and therapeutic potential for the treatment of skin pathologies such as melanoma, chronic wounds and inflammatory skin diseases or for their use in anti-aging cosmeceuticals.

Potentials of ribosomopathy gene as pharmaceutical targets for cancer treatment

Ribosomopathies encompass a spectrum of disorders arising from impaired ribosome biogenesis and reduced functionality. Mutation or dysexpression of the genes that disturb any finely regulated steps of ribosome biogenesis can result in different types of ribosomopathies in clinic, collectively known as ribosomopathy genes. Emerging data suggest that ribosomopathy patients exhibit a significantly heightened susceptibility to cancer. Abnormal ribosome biogenesis and dysregulation of some ribosomopathy genes have also been found to be intimately associated with cancer development. The correlation between ribosome biogenesis or ribosomopathy and the development of malignancies has been well established. This work aims to review the recent advances in the research of ribosomopathy genes among human cancers and meanwhile, to excavate the potential role of these genes, which have not or rarely been reported in cancer, in the disease development across cancers. We plan to establish a theoretical framework between the ribosomopathy gene and cancer development, to further facilitate the potential of these genes as diagnostic biomarker as well as pharmaceutical targets for cancer treatment.

Dysregulation of intercellular communication in vitro and in vivo via extracellular vesicles secreted by pancreatic duct adenocarcinoma cells and generated under the influence of the AG9 elastin peptide-conditioned microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with poor prognosis due to its highly metastatic profile. Intercellular communication between cancer and stromal cells via extracellular vesicles (EVs) is crucial for the premetastatic microenvironment preparation leading to tumour metastasis. This study shows that under the influence of bioactive peptides derived from the extracellular matrix microenvironment, illustrated here by the AG-9 elastin-derived peptide (EDP), PDAC cells secrete more tumour-derived EVs. Compared to PDAC-derived EVs, tumour-derived EVs resulting from AG-9 treatment (PDAC AG-9-derived EVs) significantly stimulated cell proliferation. At constant amount, tumour-derived EVs were similarly taken up by PDAC and HMEC-1 cells. Tumour-derived EVs stimulated cell proliferation, migration, proteinase secretion, and angiogenesis. Bioluminescence imaging allowed tumour-derived EV/FLuc+ tracking in vivo in a PDAC mouse model. The biodistribution of PDAC AG-9-derived EVs was different to PDAC-derived EVs. Our results demonstrate that the microenvironment, through EDP release, may not only influence the genesis of EVs but may also affect tumour progression (tumour growth and angiogenesis), and metastatic homing by modifying the in vivo biodistribution of tumour-derived EVs. They are potential candidates for targeted drug delivery and modulation of tumour progression, and they constitute a new generation of therapeutic tools, merging oncology and genic therapy.

Enolase of Streptococcus suis serotype 2 promotes biomolecular condensation of ribosomal protein SA for HBMECs apoptosis

BACKGROUND

Ribosomal protein SA (RPSA) of human brain microvascular endothelial cells (HBMECs) can transfer from the cytosol to the cell surface and act as a receptor for some pathogens, including Streptococcus suis serotype 2 (SS2), a zoonotic pathogen causing meningitis in pigs and humans. We previously reported that SS2 virulence factor enolase (ENO) binds to RPSA on the cell surface of HBMECs and induces apoptosis. However, the mechanism that activates RPSA translocation to the cell surface and induces ENO-mediated HBMEC apoptosis is unclear.

RESULTS

Here, we show that RPSA localization and condensation on the host cell surface depend on its internally disordered region (IDR). ENO binds to the IDR of RPSA and promotes its interaction with RPSA and vimentin (VIM), which is significantly suppressed after 1,6-Hexanediol (1,6-Hex, a widely used tool to disrupt phase separation) treatment, indicating that ENO incorporation and thus the concentration of RPSA/VIM complexes via co-condensation. Furthermore, increasing intracellular calcium ions (Ca2+) in response to SS2 infection further facilitates the liquid-like condensation of RPSA and aggravates ENO-induced HBMEC cell apoptosis.

CONCLUSIONS

Together, our study provides a previously underappreciated molecular mechanism illuminating that ENO-induced RPSA condensation activates the migration of RPSA to the bacterial cell surface and stimulates SS2-infected HBMEC death and, potentially, disease progression. This study offers a fresh avenue for investigation into the mechanism by which other harmful bacteria infect hosts via cell surfaces' RPSA.

hdWGCNA and Cellular Communication Identify Active NK Cell Subtypes in Alzheimer's Disease and Screen for Diagnostic Markers through Machine Learning

BACKGROUND

Alzheimer's disease (AD) is a recognized complex and severe neurodegenerative disorder, presenting a significant challenge to global health. Its hallmark pathological features include the deposition of β-amyloid plaques and the formation of neurofibrillary tangles. Given this context, it becomes imperative to develop an early and accurate biomarker model for AD diagnosis, employing machine learning and bioinformatics analysis.

METHODS

In this study, single-cell data analysis was employed to identify cellular subtypes that exhibited significant differences between the diseased and control groups. Following the identification of NK cells, hdWGCNA analysis and cellular communication analysis were conducted to pinpoint NK cell subset with the most robust communication effects. Subsequently, three machine learning algorithms-LASSO, Random Forest, and SVM-RFE-were employed to jointly screen for NK cell subset modular genes highly associated with AD. A logistic regression diagnostic model was then designed based on these characterized genes. Additionally, a protein-protein interaction (PPI) networks of model genes was established. Furthermore, unsupervised cluster analysis was conducted to classify AD subtypes based on the model genes, followed by the analysis of immune infiltration in the different subtypes. Finally, Spearman correlation coefficient analysis was utilized to explore the correlation between model genes and immune cells, as well as inflammatory factors.

RESULTS

We have successfully identified three genes (RPLP2, RPSA, and RPL18A) that exhibit a high association with AD. The nomogram based on these genes provides practical assistance in diagnosing and predicting patients' outcomes. The interconnected genes screened through PPI are intricately linked to ribosome metabolism and the COVID-19 pathway. Utilizing the expression of modular genes, unsupervised cluster analysis unveiled three distinct AD subtypes. Particularly noteworthy is subtype C3, characterized by high expression, which correlates with immune cell infiltration and elevated levels of inflammatory factors. Hence, it can be inferred that the establishment of an immune environment in AD patients is closely intertwined with the heightened expression of model genes.

CONCLUSION

This study has not only established a valuable diagnostic model for AD patients but has also delved deeply into the pivotal role of model genes in shaping the immune environment of individuals with AD. These findings offer crucial insights into early AD diagnosis and patient management strategies.

A multimodal imaging study to highlight elastin-derived peptide pro-tumoral effect in a pancreatic xenograft model

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is highly malignant with a very poor prognosis due to its silent development and metastatic profile with a 5-year survival rate below 10%. PDAC is characterised by an abundant desmoplastic stroma modulation that influences cancer development by extracellular matrix/cell interactions. Elastin is a key element of the extracellular matrix. Elastin degradation products (EDPs) regulate numerous biological processes such as cell proliferation, migration and invasion. The aim of the present study was to characterise for the first time the effect of two EDPs with consensus sequences "GxxPG" and "GxPGxGxG" (VG-6 and AG-9) on PDAC development. The ribosomal protein SA (RPSA) has been discovered recently, acting as a new receptor of EDPs on the surface of tumour cells, contributing to poor prognosis.

METHODS

Six week-old female Swiss nude nu/nu (Nu(Ico)-Foxn1nu) mice were subcutaneously injected with human PDAC MIA PaCa-2/eGFP-FLuc+ cells, transduced with a purpose-made lentiviral vector, encoding green fluorescent protein (GFP) and Photinus pyralis (firefly) luciferase (FLuc). Animals were treated three times per week with AG-9 (n = 4), VG-6 (n = 5) or PBS (n = 5). The influence of EDP on PDAC was examined by multimodal imaging (bioluminescence imaging (BLI), fluorescence imaging (FLI) and magnetic resonance imaging (MRI). Tumour volumes were also measured using a caliper. Finally, immunohistology was performed at the end of the in vivo study.

RESULTS

After in vitro validation of MIA PaCa-2 cells by optical imaging, we demonstrated that EDPs exacerbate tumour growth in the PDAC mouse model. While VG-6 stimulated tumour growth to some extent, AG-9 had greater impact on tumour growth. We showed that the expression of the RPSA correlates with a possible effect of EDPs in the PDAC model. Multimodal imaging allowed for longitudinal in vivo follow-up of tumour development. In all groups, we showed mature vessels ending in close vicinity of the tumour, except for the AG-9 group where mature vessels are penetrating the tumour reflecting an increase of vascularisation.

CONCLUSIONS

Our results suggest that AG-9 strongly increases PDAC progression through an increase in tumour vascularisation.

Folylpolyglutamate synthetase mRNA G-quadruplexes regulate its cell protrusion localization and enhance a cancer cell invasive phenotype upon folate repletion

BACKGROUND

Folates are crucial for the biosynthesis of nucleotides and amino acids, essential for cell proliferation and development. Folate deficiency induces DNA damage, developmental defects, and tumorigenicity. The obligatory enzyme folylpolyglutamate synthetase (FPGS) mediates intracellular folate retention via cytosolic and mitochondrial folate polyglutamylation. Our previous paper demonstrated the association of the cytosolic FPGS (cFPGS) with the cytoskeleton and various cell protrusion proteins. Based on these recent findings, the aim of the current study was to investigate the potential role of cFPGS at cell protrusions.

RESULTS

Here we uncovered a central role for two G-quadruplex (GQ) motifs in the 3'UTR of FPGS mediating the localization of cFPGS mRNA and protein at cell protrusions. Using the MBSV6-loop reporter system and fluorescence microscopy, we demonstrate that following folate deprivation, cFPGS mRNA is retained in the endoplasmic reticulum, whereas upon 15 min of folate repletion, this mRNA is rapidly translocated to cell protrusions in a 3'UTR- and actin-dependent manner. The actin dependency of this folate-induced mRNA translocation is shown by treatment with Latrunculin B and inhibitors of the Ras homolog family member A (RhoA) pathway. Upon folate repletion, the FPGS 3'UTR GQs induce an amoeboid/mesenchymal hybrid cell phenotype during migration and invasion through a collagen gel matrix. Targeted disruption of the 3'UTR GQ motifs by introducing point mutations or masking them by antisense oligonucleotides abrogated cell protrusion targeting of cFPGS mRNA.

CONCLUSIONS

Collectively, the GQ motifs within the 3'UTR of FPGS regulate its transcript and protein localization at cell protrusions in response to a folate cue, inducing cancer cell invasive phenotype. These novel findings suggest that the 3'UTR GQ motifs of FPGS constitute an attractive druggable target aimed at inhibition of cancer invasion and metastasis.

Urinary extracellular vesicles miRNA-A new era of prostate cancer biomarkers

Prostate cancer is the second most common male cancer worldwide showing the highest rates of incidence in Western Europe. Although the measurement of serum prostate-specific antigen levels is the current gold standard in PCa diagnosis, PSA-based screening is not considered a reliable diagnosis and prognosis tool due to its lower sensitivity and poor predictive score which lead to a 22%-43% overdiagnosis, unnecessary biopsies, and over-treatment. These major limitations along with the heterogeneous nature of the disease have made PCa a very unappreciative subject for diagnostics, resulting in poor patient management; thus, it urges to identify and validate new reliable PCa biomarkers that can provide accurate information in regard to disease diagnosis and prognosis. Researchers have explored the analysis of microRNAs (miRNAs), messenger RNAs (mRNAs), small proteins, genomic rearrangements, and gene expression in body fluids and non-solid tissues in search of lesser invasive yet efficient PCa biomarkers. Although the presence of miRNAs in body fluids like blood, urine, and saliva initially sparked great interest among the scientific community; their potential use as liquid biopsy biomarkers in PCa is still at a very nascent stage with respect to other well-established diagnostics and prognosis tools. Up to date, numerous studies have been conducted in search of PCa miRNA-based biomarkers in whole blood or blood serum; however, only a few studies have investigated their presence in urine samples of which less than two tens involve the detection of miRNAs in extracellular vesicles isolated from urine. In addition, there exists some discrepancy around the identification of miRNAs in PCa urine samples due to the diversity of the urine fractions that can be targeted for analysis such as urine circulating cells, cell-free fractions, and exosomes. In this review, we aim to discuss research output from the most recent studies involving the analysis of urinary EVs for the identification of miRNA-based PCa-specific biomarkers.

Matrikines as mediators of tissue remodelling

Extracellular matrix (ECM) proteins confer biomechanical properties, maintain cell phenotype and mediate tissue repair (via release of sequestered cytokines and proteases). In contrast to intracellular proteomes, where proteins are monitored and replaced over short time periods, many ECM proteins function for years (decades in humans) without replacement. The longevity of abundant ECM proteins, such as collagen I and elastin, leaves them vulnerable to damage accumulation and their host organs prone to chronic, age-related diseases. However, ECM protein fragmentation can potentially produce peptide cytokines (matrikines) which may exacerbate and/or ameliorate age- and disease-related ECM remodelling. In this review, we discuss ECM composition, function and degradation and highlight examples of endogenous matrikines. We then critically and comprehensively analyse published studies of matrix-derived peptides used as topical skin treatments, before considering the potential for improvements in the discovery and delivery of novel matrix-derived peptides to skin and internal organs. From this, we conclude that while the translational impact of matrix-derived peptide therapeutics is evident, the mechanisms of action of these peptides are poorly defined. Further, well-designed, multimodal studies are required.

Extracellular vesicle secretion is tissue-dependent ex vivo and skeletal muscle myofiber extracellular vesicles reach the circulation in vivo

Extracellular vesicles (EVs) are biomarkers and modifiers of human disease. EVs secreted by insulin-responsive tissues like skeletal muscle (SkM) and white adipose tissue (WAT) contribute to metabolic health and disease but the relative abundance of EVs from these tissues has not been directly examined. Human Protein Atlas data and directly measuring EV secretion in mouse SkM and WAT using an ex vivo tissue explant model confirmed that SkM tissue secretes more EVs than WAT. Differences in EV secretion between SkM and WAT were not due to SkM contraction but may be explained by differences in tissue metabolic capacity. We next examined how many EVs secreted from SkM tissue ex vivo and in vivo are myofiber-derived. To do this, a SkM myofiber-specific dual fluorescent reporter mouse was created. Spectral flow cytometry revealed that SkM myofibers are a major source of SkM tissue-derived EVs ex vivo and EV immunocapture indicates that ∼5% of circulating tetraspanin-positive EVs are derived from SkM myofibers in vivo. Our findings demonstrate that 1) SkM secretes more EVs than WAT, 2) many SkM tissue EVs are derived from SkM myofibers, and 3) SkM myofiber-derived EVs reach the circulation in vivo. These findings advance our understanding of EV secretion between metabolically active tissues and provide direct evidence that SkM myofibers secrete EVs that can reach the circulation in vivo.

The potential role of cofilin-1 in promoting triple negative breast cancer (TNBC) metastasis via the extracellular vesicles (EVs)

Triple negative breast cancer (TNBC) is an aggressive cancer, particularly prone to metastasis and is associated with poor survival outcomes. The key to unravelling the aggressiveness of TNBC lies in decoding the mechanism by which it metastasises. Cofilin-1 is a well-studied member of the cofilin family, involved in actin depolymerisation. Studies have described the diverse roles of cofilin-1 including cell motility, apoptosis and lipid metabolism. Levels of cofilin-1 have been shown to be increased in many different types of malignant cells, with increased cofilin-1 protein levels associated with poor prognosis in patients with TNBC. Extracellular vesicles (EVs) are microvesicles typically around 100 nm in size, found in all biological fluids examined to date (Lötvall et al., 2014). Proteomic studies on extracellular vesicles (EVs) have shown that cofilin-1 is amongst the most frequently detected. Moreover, decreased levels of cofilin-1 potentially inhibit the release of EVs from cells. Additionally, Cofilin-1 is essential for the maturation of EVs and may also play a key role in the establishment of the pre-metastatic niche, thus promoting tumour cell migration. Further work into the exact mechanism by which cofilin-1 advances TNBC metastasis, may potentially prevent disease progression and improve outcomes for patients with TNBC.

Circular RNA Circ_0000677 promotes cell proliferation by regulating microRNA-106b-5p/CCND1 in non-small cell lung cancer

Recently, circular RNAs (circRNAs) have become an intense focus of research and large numbers of circRNAs have been identified, awaiting functional elucidation. Thus, the present study aims to examine the regulation of circRNAs and its molecular mechanism in lung cancer growth. Here, we show that circular RNA circ_0000677 was overexpressed and correlated with poor prognosis in non‐small cell lung cancer (NSCLC) patients. Functionally, circ_0000677 knockdown markedly inhibited proliferation of NSCLC cells by observing of immunofluorescence staining of Ki67, clone formation assay, and xenograft experiments. In mechanism, circ_0000677 acted as a sponge of microRNA-106b and further regulated CCDND1 gene expression in NSCLC cells by dual luciferase activity assay and their expression examination. Taken together, these findings suggest a role for circ_0000677/miR-106b/CCND1 regulation axis in promoting NSCLC growth and progression.

Proteomic profiling in extracellular vesicles for cancer detection and monitoring

Extracellular vesicles (EVs) are nanometer-size lipid vesicles released by cells, which play essential biological functions in intercellular communication. Increasing evidence indicates that EVs participate in cancer development, including invasion, migration, metastasis, and cancer immune modulation. One of the key mechanisms is that EVs affect different cells in the tumor microenvironment through surface-anchor proteins and protein cargos. Moreover, proteins specifically expressed in tumor-derived EVs can be applied in cancer diagnosis and monitoring. Besides, the EV proteome also helps to understand drug resistance in cancers and to guide clinical medication. With the development of mass spectrometry and array-based multi-protein detection, the research of EV proteomics has entered a new era. The high-throughput parallel proteomic profiling based on these new platforms allows us to study the impact of EV proteome on cancer progression more comprehensively and to describe the proteomic landscape in cancers with more details. In this article, we review the role and function of different types of EVs in cancer progression. More importantly, we summarize the proteomic profiling of EVs based on different methods and the application of EV proteome in cancer detection and monitoring.

AG-9, an Elastin-Derived Peptide, Increases In Vitro Oral Tongue Carcinoma Cell Invasion, through an Increase in MMP-2 Secretion and MT1-MMP Expression, in a RPSA-Dependent Manner

Oral tongue squamous cell carcinoma is one of the most prevalent head and neck cancers. During tumor progression, elastin fragments are released in the tumor microenvironment. Among them, we previously identified a nonapeptide, AG-9, that stimulates melanoma progression in vivo in a mouse melanoma model. In the present paper, we studied AG-9 effect on tongue squamous cell carcinoma invasive properties. We demonstrated that AG-9 stimulates cell invasion in vitro in a modified Boyen chamber model. It increases MMP-2 secretion, analyzed by zymography and MT1-MMP expression, studied by Western blot. The stimulatory effect was mediated through Ribosomal Protein SA (RPSA) receptor binding as demonstrated by SiRNA experiments. The green tea-derived polyphenol, (−)-epigallocatechin-3-gallate (EGCG), was previously shown to bind RPSA. Molecular docking experiments were performed to compare the preferred areas of interaction of AG-9 and EGCG with RPSA and suggested overlapping areas. This was confirmed by competition assays. EGCG abolished AG-9-induced invasion, MMP-2 secretion, and MT1-MMP expression.

Endothelial Basement Membrane Components and Their Products, Matrikines: Active Drivers of Pulmonary Hypertension?

Pulmonary arterial hypertension (PAH) is a vascular disease that is characterized by elevated pulmonary arterial pressure (PAP) due to progressive vascular remodeling. Extracellular matrix (ECM) deposition in pulmonary arteries (PA) is one of the key features of vascular remodeling. Emerging evidence indicates that the basement membrane (BM), a specialized cluster of ECM proteins underlying the endothelium, may be actively involved in the progression of vascular remodeling. The BM and its steady turnover are pivotal for maintaining appropriate vascular functions. However, the pathologically elevated turnover of BM components leads to an increased release of biologically active short fragments, which are called matrikines. Both BM components and their matrikines can interfere with pivotal biological processes, such as survival, proliferation, adhesion, and migration and thus may actively contribute to endothelial dysfunction. Therefore, in this review, we summarize the emerging role of the BM and its matrikines on the vascular endothelium and further discuss its implications on lung vascular remodeling in pulmonary hypertension.

Extracellular Vesicle-Dependent Cross-Talk in Cancer-Focus on Pancreatic Cancer

Extracellular vesicles (EVs) like exosomes and shed microvesicles are generated by many different cells. However, among all the cells, cancer cells are now recognized to secrete more EVs than healthy cells. Tumor-derived EVs can be isolated from biofluids such as blood, urine, ascitic fluid, and saliva. Their numerous components (nucleic acids, proteins, and lipids) possess many pleiotropic functions involved in cancer progression. The tumor-derived EVs generated under the influence of tumor microenvironment play distant roles and promote cellular communication by directly interacting with different cells. Moreover, they modulate extracellular matrix remodeling and tumor progression. Tumor-derived EVs are involved in pre-metastatic niche formation, dependent on the EV-associated protein receptors, and in cancer chemoresistance as they transfer drug-resistance-related genes to recipient cells. Recent advances in preclinical and clinical fields suggest their potential use as biomarkers for diagnosis and prognosis as well as for drug delivery in cancer. In this Review, we discuss EV characteristics and pro-tumor capacities, and highlight the future crucial impact of tumor-derived EVs in pancreatic cancer diagnosis and prognosis.

TRPM7/RPSA Complex Regulates Pancreatic Cancer Cell Migration

Pancreatic ductal adenocarcinoma (PDAC) is a malignancy with a very poor prognosis due to highly metastatic profile. Cell migration is an essential step of the metastatic cascade allowing cancer cells to spread toward target tissues. Recent studies strongly suggest that bioactive elastin peptides, also named elastokines or elastin-derived peptides (EDPs), are released in the extracellular microenvironment during tumoral remodeling of the stroma. EDPs stimulate cancer cell migration by interacting with their membrane receptor, ribosomal protein SA (RPSA). Others membrane proteins like ion channels are also involved in cancer cell migration. It has been recently shown that the transient receptor potential melastatin-related 7 (TRPM7) channel regulates PDAC cell migration and invasion. The objective of this work was to study the effect of EDPs on TRPM7 channel in human pancreatic cancer cells. We showed that EDPs promote MIA PaCa-2 cell migration using Boyden chamber assay. Cells transfected with a siRNA targeting TRPM7 were not able to migrate in response to EDPs indicating that TRPM7 regulated cell migration induced by these peptides. Moreover, EDPs were able to stimulate TRPM7 currents recorded by Patch-Clamp. Finally, we showed that TRPM7 channels and RPSA receptors are colocalized at the plasma membrane of human pancreatic cancer cells. Taken together, our data suggest that TRPM7/RPSA complex regulated human pancreatic cancer cell migration. This complex may be a promising therapeutic target in PDAC.

Structural Analysis of Nonapeptides Derived from Elastin

Elastin-derived peptides are released from the extracellular matrix remodeling by numerous proteases and seem to regulate many biological processes, notably cancer progression. The canonical elastin peptide is VGVAPG, which harbors the XGXXPG consensus pattern, allowing interaction with the elastin receptor complex located at the surface of cells. Besides these elastokines, another class of peptides has been identified. This group of bioactive elastin peptides presents the XGXPGXGXG consensus sequence, but the reason for their bioactivity remains unexplained. To better understand their nature and structure-function relationships, herein we searched the current databases for this nonapeptide motif and observed that the XGXPGXGXG elastin peptides define a specific group of tandemly repeated patterns. Further, we focused on four tandemly repeated human elastin nonapeptides, i.e., AGIPGLGVG, VGVPGLGVG, AGVPGLGVG, and AGVPGFGAG. These peptides were analyzed by means of optical spectroscopies and molecular dynamics. Ultraviolet-circular dichroism and Raman spectra are consistent with a mixture of β-turn, β-strand, and random-chain secondary elements in aqueous media. Quantitative analysis of their conformations suggested that turns corresponded to half of the total population of structural elements, whereas the remaining half were equally distributed between β-strand and unordered chains. These distributions were confirmed by molecular dynamics simulations. Altogether, our data suggest that these highly dynamic peptides harbor a type II β-turn located in their central part. We hypothesize that this structural element could explain their specific bioactivity.

Tumor Microenvironment: Extracellular Matrix Alterations Influence Tumor Progression

The tumor microenvironment (TME) is composed of various cell types embedded in an altered extracellular matrix (ECM). ECM not only serves as a support for tumor cell but also regulates cell-cell or cell-matrix cross-talks. Alterations in ECM may be induced by hypoxia and acidosis, by oxygen free radicals generated by infiltrating inflammatory cells or by tumor- or stromal cell-secreted proteases. A poorer diagnosis for patients is often associated with ECM alterations. Tumor ECM proteome, also named cancer matrisome, is strongly altered, and different ECM protein signatures may be defined to serve as prognostic biomarkers. Collagen network reorganization facilitates tumor cell invasion. Proteoglycan expression and location are modified in the TME and affect cell invasion and metastatic dissemination. ECM macromolecule degradation by proteases may induce the release of angiogenic growth factors but also the release of proteoglycan-derived or ECM protein fragments, named matrikines or matricryptins. This review will focus on current knowledge and new insights in ECM alterations, degradation, and reticulation through cross-linking enzymes and on the role of ECM fragments in the control of cancer progression and their potential use as biomarkers in cancer diagnosis and prognosis.

Large extracellular vesicles: Size matters in tumor progression

Extracellular Vesicles (EVs) represent a heterogeneous population of particles naturally released from all cells, delimited by a lipid bilayer and able to horizontally transfer their cargos to recipient cells. These features imply the growing interest on EVs in cancer biology as biomarkers and therapeutic targets. In this review, we will highlight the specific process related to biogenesis and release of large EVs (L-EVs) derived from the plasma membrane (PM) compared to the small and well described exosomes, generated through the classical endosome-multivesicular body (MVB) pathway. The control of PM rigidity by cells depends on lipid/protein composition, cytoskeleton dynamics, cytoplasmic viscosity, ions balance, metabolic reprogramming and specific intracellular signaling pathways, all critical determinants of L-EVs biogenesis. We will focus in details on a specific class of L-EVs, named Large Oncosomes (LO), exclusively shed by cancer cells and with a size ranging from 1 μm up to 10 μm. We will examine LO specific cargos, either proteins or nucleic acids (i.e. mRNA, microRNAs, single/double-stranded DNA), as well as their functional role in cancer development and progression, also discussing the mechanisms of L-EVs internalization by recipient cells. Overall we will highlight the potential of LO as specific diagnostic/prognostic cancer biomarkers discussing the associated challenges.