Secretome proteomics reveals candidate non-invasive biomarkers of BRCA1 deficiency in breast cancer

The Role of Extracellular Vesicles in the Treatment of Prostate Cancer

Prostate cancer (PCa) has become a public health concern in elderly men due to an ever-increasing number of estimated cases. Unfortunately, the available treatments are unsatisfactory because of a lack of a durable response, especially in advanced disease states. Extracellular vesicles (EVs) are lipid-bilayer encircled nanoscale vesicles that carry numerous biomolecules (e.g., nucleic acids, proteins, and lipids), mediating the transfer of information. The past decade has witnessed a wide range of EV applications in both diagnostics and therapeutics. First, EV-based non-invasive liquid biopsies provide biomarkers in various clinical scenarios to guide treatment; EVs can facilitate the grading and staging of patients for appropriate treatment selection. Second, EVs play a pivotal role in pathophysiological processes via intercellular communication. Targeting key molecules involved in EV-mediated tumor progression (e.g., proliferation, angiogenesis, metastasis, immune escape, and drug resistance) is a potential approach for curbing PCa. Third, EVs are promising drug carriers. Naïve EVs from various sources and engineered EV-based drug delivery systems have paved the way for the development of new treatment modalities. This review discusses the recent advancements in the application of EV therapies and highlights EV-based functional materials as novel interventions for PCa.

Mass spectrometry for the study of adipocyte cell secretome in cardiovascular diseases

Adipose tissue is classically considered the primary site of lipid storage, but in recent years has garnered appreciation for its broad role as an endocrine organ, capable of remotely signaling to other tissues to alter their metabolic program. The adipose tissue is now recognized as a crucial regulator of cardiovascular health, mediated by the secretion of several bioactive products, with a wide range of endocrine and paracrine effects on the cardiovascular system. Thanks to the development and improvement of high-throughput mass spectrometry, the size and components of the human secretome have been characterized. In this review, we summarized the recent advances in mass spectrometry-based studies of the cell and tissue secretome for the understanding of adipose tissue biology, which may help to decipher the complex molecular mechanisms controlling the crosstalk between the adipose tissue and the cardiovascular system, and their possible clinical translation.

Extracellular vesicle proteins as breast cancer biomarkers: Mass spectrometry-based analysis

Extracellular vesicles (EVs) are membrane-surrounded vesicles released by various cell types into the extracellular microenvironment. Although EVs vary in size, biological function, and components, their importance in cancer progression and the potential use of EV molecular species to serve as novel cancer biomarkers have become increasingly evident. Cancer cells actively release EVs into surrounding tissues, which play vital roles in cancer progression and metastasis, including invasion and immune modulation. EVs released by cancer cells are usually chosen as a gateway in the search for biomarkers for cancer. In this review, we mainly focused on molecular profiling of EV protein constituents from breast cancer, emphasizing mass spectrometry (MS)-based proteomic approaches. To further investigate the potential use of EVs as a source of breast cancer biomarkers, we have discussed the use of these proteins as predictive marker candidates. Besides, we have also summarized the key characteristics of EVs as potential therapeutic targets in breast cancer and provided significant information on their implications in breast cancer development and progression. Information provided in this review may help understand the recent progress in understanding EV biology and their potential role as new noninvasive biomarkers as well as emerging therapeutic opportunities and associated challenges.

Protein biomarkers in breast cancer-derived extracellular vesicles for use in liquid biopsies

Breast cancer is the most common malignant disease in women worldwide. Early diagnosis and treatment can greatly improve the management of breast cancer. Liquid biopsies are becoming convenient detection methods for diagnosing and monitoring breast cancer due to their noninvasiveness and ability to provide real-time feedback. A range of liquid biopsy markers, including circulating tumor proteins, circulating tumor cells, and circulating tumor nucleic acids, have been implemented for breast cancer diagnosis and prognosis, with each having its own advantages and limitations. Circulating extracellular vesicles are messengers of intercellular communication that are packed with information from mother cells and are found in a wide variety of bodily fluids; thus, they are emerging as ideal candidates for liquid biopsy biomarkers. In this review, we summarize extracellular vesicle protein markers that can be potentially used for the early diagnosis and prognosis of breast cancer or determining its specific subtypes.

Application of extracellular vesicles in the diagnosis and treatment of prostate cancer: Implications for clinical practice

Extracellular vesicles (EV) are cell-derived lipid bilayer-delimited structures providing an important means of intercellular communication. Recent studies have shown that EV, particularly exosomes and large-oncosomes contain miRNA and proteins crucial in prostate cancer (PCa) progression, metastasis and treatment resistance. This includes not just EV released from PCa cells, but also from other cells in the tumor microenvironment. PCa patient derived EV have a unique composition compared to healthy and benign prostatic diseases. As such, EV show promise as diagnostic liquid biopsy biomarkers, both as an adjunct and alternative to the invasive current gold-standard. EV could also be utilized to stratify patients' risk and predict response to hormonal, chemo, immune- and targeted therapy, which will direct future treatment decisions in PCa. We present a summary of the current evidence on the role of EV in PCa and the application of EV in PCa diagnosis and treatment to optimize patient outcomes.

Recent Developments and Applications of Quantitative Proteomics Strategies for High-Throughput Biomolecular Analyses in Cancer Research

Innovations in medical technology and dedicated focus from the scientific community have inspired numerous treatment strategies for benign and invasive cancers. While these improvements often lend themselves to more positive prognoses and greater patient longevity, means for early detection and severity stratification have failed to keep pace. Detection and validation of cancer-specific biomarkers hinges on the ability to identify subtype-specific phenotypic and proteomic alterations and the systematic screening of diverse patient groups. For this reason, clinical and scientific research settings rely on high throughput and high sensitivity mass spectrometry methods to discover and quantify unique molecular perturbations in cancer patients. Discussed within is an overview of quantitative proteomics strategies and a summary of recent applications that enable revealing potential biomarkers and treatment targets in prostate, ovarian, breast, and pancreatic cancer in a high throughput manner.

Trastuzumab Modulates the Protein Cargo of Extracellular Vesicles Released by ERBB2+ Breast Cancer Cells

Cancers overexpressing the ERBB2 oncogene are aggressive and associated with a poor prognosis. Trastuzumab is an ERBB2 specific recombinant antibody employed for the treatment of these diseases since it blocks ERBB2 signaling causing growth arrest and survival inhibition. While the effects of Trastuzumab on ERBB2 cancer cells are well known, those on the extracellular vesicles (EVs) released from these cells are scarce. This study focused on ERBB2⁺ breast cancer cells and aimed to establish what type of EVs they release and whether Trastuzumab affects their morphology and molecular composition. To these aims, we performed immunoelectron microscopy, immunoblot, and high-resolution mass spectrometry analyses on EVs purified by differential centrifugation of culture supernatant. Here, we show that EVs released from ERBB2⁺ breast cancer cells are polymorphic in size and appearance and that ERBB2 is preferentially associated with large (120 nm) EVs. Moreover, we report that Trastuzumab (Tz) induces the expression of a specific glycosylated 50 kDa isoform of the CD63 tetraspanin and modulates the expression of 51 EVs proteins, including TOP1. Because these proteins are functionally associated with organelle organization, cytokinesis, and response to lipids, we suggest that Tz may influence these cellular processes in target cells at distant sites via modified EVs.

Exosomes as Pleiotropic Players in Pancreatic Cancer

Pancreatic cancer (PC) incidence is rising and due to late diagnosis, combined with unsatisfactory response to current therapeutic approaches, this tumor has an extremely high mortality rate. A better understanding of the mechanisms underlying pancreatic carcinogenesis is of paramount importance for rational diagnostic and therapeutic approaches. Multiple lines of evidence have showed that exosomes are actively involved in intercellular communication by transferring their cargos of bioactive molecules to recipient cells within the tumor microenvironment and systemically. Intriguingly, exosomes may exert both protumor and antitumor effects, supporting or hampering processes that play a role in the pathogenesis and progression of PC, including shifts in tumor metabolism, proliferation, invasion, metastasis, and chemoresistance. They also have a dual role in PC immunomodulation, exerting immunosuppressive or immune enhancement effects through several mechanisms. PC-derived exosomes also induce systemic metabolic alterations, leading to the onset of diabetes and weight loss. Moreover, exosomes have been described as promising diagnostic and prognostic biomarkers for PC. Their potential application in PC therapy as drug carriers and therapeutic targets is under investigation. In this review, we provide an overview of the multiple roles played by exosomes in PC biology through their specific cargo biomolecules and of their potential exploitation in early diagnosis and treatment of PC.

Preclinical Characterization of the Radioimmunoconjugate 111In or 90Y-FF-21101 Against a P-Cadherin-Expressing Tumor in a Mouse Xenograft Model and a Nonhuman Primate

P-cadherin is overexpressed in various cancers and can be a target for radioimmunotherapy. We investigated the preclinical pharmacokinetics and pharmacology of FF-21101, an ¹¹¹In- or ⁹⁰Y-conjugated monoclonal antibody against P-cadherin, to evaluate its clinical applications. Methods: The radiochemical purity, binding affinity, and in vitro serum stability of ¹¹¹In or ⁹⁰Y-labeled FF-21101 were evaluated. The pharmacokinetics of ¹¹¹In or ⁹⁰Y-FF-21101 were compared in normal mice. Tumor accumulation after ¹¹¹In-FF-21101 administration was investigated in mice bearing subcutaneous tumors with high (NCI-H1373), moderate (EBC-1), or no (A549) P-cadherin expression. The tumor suppression effect after a single intravenous injection of ⁹⁰Y-FF-21101 was assessed in NCI-H1373 and EBC-1 mouse xenograft models. The relationship between antibody dose and tumor accumulation was investigated in the NCI-H1373 mouse xenograft model. The absorbed radiation dose in humans after injection of ⁹⁰Y-FF-21101 was estimated using γ-camera images of cynomolgus monkeys. Results: The radiochemical purities of ¹¹¹In- and ⁹⁰Y-FF-21101 were 98.2% ± 2.5% (n = 9) and 99.3% ± 0.6% (n = 5), respectively. The dissociation constants were 1.083 nM for ¹¹¹In-FF-21101 and 1.367 nM for ⁹⁰Y-FF-21101. Both ¹¹¹In- and ⁹⁰Y-FF-21101 were stable in human serum after 96 h of incubation and exhibited similar pharmacokinetics in normal mice. The tumor accumulation of ¹¹¹In-FF-21101 was closely related to the intensity of P-cadherin expression in the cells. ⁹⁰Y-FF-21101 showed significant tumor growth inhibition, indicating that NCI-H1373 and EBC-1 recurrence was not observed after intravenous administration of 3.7 and 7.4 MBq, respectively of ⁹⁰Y-FF-21101 per animal. Tumor uptake in the mouse xenograft model and estimated absorbed radiation doses in the spleen of monkeys decreased with increasing antibody doses of ¹¹¹In-FF-21101. Conversely, the estimated absorbed radiation dose in the red marrow increased with increasing antibody dose. An antibody dose of 4.8 mg/m² was considered appropriate for humans, on the basis of efficacy and safety. The maximum tolerated administered activity of ⁹⁰Y-FF-21101 was estimated to be 2,886 MBq/human. Conclusion: FF-21101 radioimmunotherapy exhibited high antitumor affinity and antitumor efficacy in mouse xenograft models. Extrapolation of the pharmacokinetics in monkeys to humans suggests the potential for clinical application of FF-21101 for treating P-cadherin–expressing tumor.

Exosomes: A Promising Avenue for the Diagnosis of Breast Cancer

Currently, despite the advances in individualized treatment, breast cancer still remains the deadliest form of cancer in women. Diagnostic, prognostic, and therapy-predictive methods are mainly based on the evaluation of tumor tissue samples and are aimed to improve the overall therapeutic level. Therefore, the exploration of a series of circulating biomarkers, which serve as the information source of tumors and could be obtained by peripheral blood samples, represents a high field of interest. Apart from classical biomarkers, exosomes, which are nanovesicles, are emerging as an accessible and efficient source of cell information. The purpose of this review is to summarize the peculiarities of the presently available breast cancer exosomal biomarkers; the review also provides the prediction of a multitude of potential target genes of exosomal microRNAs using 4 databases.

Changes in the urinary extracellular vesicle proteome are associated with nephronophthisis-related ciliopathies

Nephronophthisis is one of the leading genetic causes of end-stage renal disease in childhood. Early diagnostics and prognostics for nephronophthisis are currently limited. We aimed to identify non-invasive protein biomarkers for nephronophthisis in urinary extracellular vesicles. Extracellular vesicles were isolated from urine of 12 patients with a nephronophthisis-related ciliopathy and 12 age- and gender-matched controls, followed by in-depth label-free LC-MS/MS proteomics analysis of gel fractionated extracellular vesicle proteins. Supervised cluster analysis of proteomic profiles separated patients from controls. We identified 156 differentially expressed proteins with fold change ≥4 in patients compared to controls (P < .05). Importantly, expression levels of discriminating proteins were correlated with chronic kidney disease stage, suggesting possible applications for urinary extracellular vesicle biomarkers in prognostics for nephronophthisis. Enrichment analysis of gene ontology terms revealed GO terms including signaling, actin cytoskeleton and endocytosis among the downregulated proteins in patients, whereas terms related to response to wounding and extracellular matrix organization were enriched among upregulated proteins. Our findings represent the first step towards a non-invasive diagnostic test for nephronophthisis. Further research is needed to determine specificity of the candidate biomarkers. In conclusion, proteomic profiles of urinary extracellular vesicles differentiate nephronophthisis-related ciliopathy patients from healthy controls. SIGNIFICANCE: Nephronophthisis is an important cause of end-stage renal disease in children and is associated with an average diagnostic delay of 3.5 years. This is the first study investigating candidate biomarkers for nephronophthisis using global proteomics analysis of urinary extracellular vesicles in patients with nephronophthisis compared to control individuals. We show that measuring protein markers in urinary extracellular vesicles is a promising approach for non-invasive early diagnostics of nephronophthisis.

Exosomes promote cetuximab resistance via the PTEN/Akt pathway in colon cancer cells

Cetuximab is widely used in patients with metastatic colon cancer expressing wildtype KRAS. However, acquired drug resistance limits its clinical efficacy. Exosomes are nanosized vesicles secreted by various cell types. Tumor cell-derived exosomes participate in many biological processes, including tumor invasion, metastasis, and drug resistance. In this study, exosomes derived from cetuximab-resistant RKO colon cancer cells induced cetuximab resistance in cetuximab-sensitive Caco-2 cells. Meanwhile, exosomes from RKO and Caco-2 cells showed different levels of phosphatase and tensin homolog (PTEN) and phosphor-Akt. Furthermore, reduced PTEN and increased phosphorylated Akt levels were found in Caco-2 cells after exposure to RKO cell-derived exosomes. Moreover, an Akt inhibitor prevented RKO cell-derived exosome-induced drug resistance in Caco-2 cells. These findings provide novel evidence that exosomes derived from cetuximab-resistant cells could induce cetuximab resistance in cetuximab-sensitive cells, by downregulating PTEN and increasing phosphorylated Akt levels.