Alessandro Cama

Background: Circulating extracellular vesicle (EV)-associated particle profiles may differ between patients with melanoma and those with benign lesions. Methods: Preoperative citrated whole blood from 77 patients with clinically suspicious lesions was assessed by direct fluorescence-based flow cytometry; histopathology identified 20 CMM cases (12 primary and 8 metastatic) and 57 benign-lesion controls. Results: The reported total particle concentration was higher in CMM than controls (3299.86 ± 456.61 vs. 2873.40 ± 427.74 events/µL). CD45+, PD-L1+, and CD45+/PD-L1+ populations were also increased. CD45+/VISTA+ particles were higher in the reduced subset of 9 CMM cases and 48 controls. Conclusions: These exploratory observations require analytical validation and independent clinical confirmation before diagnostic or prognostic utility can be established.

Heart inflammation and oxidative stress are pivotal pathological drivers in the pathophysiology of various cardiovascular diseases. The present study aims to investigate the beneficial effects induced by extracts derived from edible plants, such as Olea europaea, and sugar cane on heart health. In particular, we investigated the effects of a novel combination constituting Olea europaea, Scutellaria baicalensis, and policosanol extracts on heart, in in vitro and ex vivo models. Olea europaea, S. baicalensis, policosanol extracts and their combination prevented H₂O₂-induced reduction in H9c2 cell (immortalized myoblasts, isolated from rat heart tissue) viability. Moreover, pre-incubation with the combination significantly reduced H₂O₂-induced ROS levels in the same cells. Our present findings also showed that Olea europaea, S. baicalensis and policosanol extracts, as well as their combination, increased lipopolysaccharide (LPS)-induced catalase gene expression at all concentrations tested, in mouse heart specimens. In addition, we also observed that Olea europaea, S. baicalensis and policosanol extracts, as well as their combination, significantly inhibited LPS-induced inducible nitric oxide synthase, cyclooxygenase-2, nuclear factor-kB, and tumor necrosis factor-α gene expression, in the same experimental model. Interestingly, the combination was more effective at decreasing the mRNA levels of all pro-inflammatory markers investigated. Finally, the combination was also able to suppress LPS-induced B-type natriuretic peptide and cardiac troponin I gene expression ex vivo. In conclusion, these findings suggest that this plant-based combination could offer potential benefits for cardiovascular health and support overall heart function in humans.

Chimeric antigen receptor (CAR) T-cell–derived extracellular vesicles (EVs) might represent a new therapeutic tool for boosting CAR T-cell antileukemic effects. Here, a cohort of 22 patients who received infusion with CD19 CAR T cells were monitored for the presence of circulating CD19 CAR+ T-cell–derived EVs (CD19.CAR+EVs), which were then separated and functionally characterized for their killing abilities. A good manufacturing practice (GMP)-compliant separation method was also developed. Results demonstrated that CD19.CAR+EVs were detectable in peripheral blood up to 2 years after infusion, indicating long-lasting persistence of their parental cells. Notably, early decreases of circulating CD19.CAR+EV concentrations correlated with failure of CAR T-cell therapy. Circulating CD19.CAR+EVs displayed a median size (standard deviation) of 133.1 ± 65.5 nm and carried a proapoptotic protein cargo. These EVs expressed higher CAR levels than their parental cells. Furthermore, CD19.CAR+EVs did not activate heterologous T cells and produced significant, specific, and dose-dependent cytotoxic effects on CD19+ cell lines and primary cells. The new GMP-compliant EV isolation method allowed for a recovery of 63% ± 5.7% of CD19.CAR+EVs. A deeper analysis of the different protein cargoes carried by EVs derived from different CAR T-cell subpopulations identified a proapoptotic functional pathway linked to CD8+LAG-3+ EVs. Overall, our data indicate that CD19.CAR+EVs may be proposed as promising dynamic new biomarkers of CAR T-cell activity and, by contributing to the direct killing of leukemic targets, represent a new product with strong therapeutic potential that could be infused independently of CAR T cells.

Background: Colorectal cancer is among the most prevalent causes of tumor-related deaths worldwide. Antiangiogenic therapy represents a cornerstone of metastatic CRC treatment, and biomarkers are advocated for the optimization of this therapeutic strategy. Methods: In this observational prospective study, we employed an optimized flow cytometry protocol to investigate the prognostic and predictive potential of blood circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPCs), and related subsets in a cohort of patients with metastatic colorectal cancer (n = 40). Results: Computational FC analysis revealed a differential enrichment of blood cell clusters with a CD34+/CD45dim/CD117(c-kit)+ phenotype between responders and non-responders both to antiangiogenic and non-antiangiogenic treatments. Intriguingly, our results show that a high percentage of annexin V-negative cells in a putative circulating progenitor population with a CD34+/CD45dim/CD117+ phenotype was correlated with a reduced response to systemic anticancer treatments (p = 0.015) and worse overall survival (log-rank p = 0.03). In addition, we observed increased blood concentrations of CD34+/CD45dim/CD117+/annexin V- cells in patients with a higher number of metastatic sites (p = 0.03). Conclusions: Overall, these findings hold promise for the identification of novel circulating biomarkers to develop more personalized treatment approaches in patients with metastatic colorectal cancer.

Colorectal cancer is among the most prevalent causes of tumour-related deaths worldwide. Antiangiogenic therapy represents a cornerstone for metastatic CRC treatment and biomarkers are advocated for the optimization of this therapeutic strategy. In this observational prospective study, we applied an optimized flow cytometry (FC) protocol to explore the prognostic and predictive potential of blood circulating endothelial cells (CEC), circulating endothelial progenitor cells (CEPC) and related subsets in a cohort of patients with metastatic colorectal cancer (n=40). Computational FC analysis revealed a differential enrichment of blood cell clusters with a CD34+/CD45dim /CD117(c-kit)+ phenotype between responders and non-responders both to antiangiogenic and non antiangiogenic treatments. Intriguingly, our results show that a high percentage of annexin V negative cells in a putative circulating progenitor population with a CD34+/CD45dim/CD117+ phenotype was correlated with reduced response to systemic anticancer treatments (p 0.005) and worse overall survival (0.03). In addition, we observed increased blood concentrations of CD34+/CD45dim/CD117+/Annexin V- cells in patients with higher number of metastatic sites (p 0.03). Overall, these findings hold promise for the identification of novel blood based biomarkers for improved personalized treatment approaches in patients affected by metastatic colorectal cancer.

Pancreatic cancer (PC) has a poor prognosis and displays resistance to immunotherapy. A better understanding of tumor-derived extracellular vesicle (EV) effects on immune responses might contribute to improved immunotherapy. EVs derived from Capan-2 and BxPC-3 PC cells isolated by ultracentrifugation were characterized by atomic force microscopy, Western blot (WB), nanoparticle tracking analysis, and label-free proteomics. Fresh PBMCs from healthy donors were treated with PC- or control-derived heterologous EVs, followed by flow cytometry analysis of CD8+ and CD4+ lymphocytes. The proteomics of lymphocytes sorted from EV-treated or untreated PBMCs was performed, and the IFN-γ concentration was measured by ELISA. Notably, most of the proteins identified in Capan-2 and BxPC-3 EVs by the proteomic analysis were connected in a single functional network (p = 1 × 10⁻¹⁶) and were involved in the “Immune System” (FDR: 1.10 × 10⁻²⁴ and 3.69 × 10⁻¹⁹, respectively). Interestingly, the treatment of healthy donor-derived PBMCs with Capan-2 EVs but not with BxPC-3 EVs or heterologous control EVs induced early activation of CD8+ and CD4+ lymphocytes. The proteomics of lymphocytes sorted from EV-treated PBMCs was consistent with their activation by Capan-2 EVs, indicating IFN-γ among the major upstream regulators, as confirmed by ELISA. The proteomic and functional analyses indicate that PC-EVs have pleiotropic effects, and some may activate early immune responses, which might be relevant for the development of highly needed immunotherapeutic strategies in this immune-cold tumor.

Pancreatic cancer (PC) has a poor prognosis and displays resistance to immunotherapy. A better understanding of tumor-derived extracellular vesicles (EVs) effects on immune responses might contribute to improved immunotherapy. EVs derived from Capan-2 and BxPC-3 PC cells isolated by ultracentrifugation were characterized by atomic force microscopy, western blot (WB), nanoparticle tracking analysis and label-free proteomics. Fresh PBMCs from healthy donors were treated with PC- or control-derived heterologous EVs followed by flow cytometry analysis of CD8+ and CD4+ lymphocytes. Proteomics of lymphocytes sorted from EV-treated, or -untreated PBMCs was performed and IFN-γ concentration was measured by ELISA. Notably, most of the proteins identified in Capan-2 and BxPC-3 EVs by proteomic analysis were connected in a single functional network (p=1x10-16) and were involved in “Immune System” (FDR: 1.10x10-24 and 3.69x10-19, respectively). Interestingly, treatment of healthy donor-derived PBMCs with Capan-2 EVs, but not with BxPC-3 EVs or heterologous control EVs induced early activation of CD8+ and CD4+ lymphocytes. Proteomics of lymphocytes sorted from EV-treated PBMCs was consistent with their activation by Capan-2 EVs, indicating IFN-γ among major upstream regulators, as confirmed by ELISA. Proteomic and functional analyses indicate that PC-EVs have pleiotropic effects, and some may activate early immune response, which might be relevant for the development of highly needed immunotherapeutic strategies in this immune-cold tumor.

Activation of peroxisome proliferator-activated receptors (PPARs) not only regulates multiple metabolic pathways, but mediates various biological effects related to inflammation and oxidative stress. We investigated the effects of four new PPAR ligands containing a fibrate scaffold—the PPAR agonists (1a (αEC₅₀ 1.0 μM) and 1b (γEC₅₀ 0.012 μM)) and antagonists (2a (αIC₅₀ 6.5 μM) and 2b (αIC₅₀ 0.98 μM, with a weak antagonist activity on γ isoform))—on proinflammatory and oxidative stress biomarkers. The PPAR ligands 1a-b and 2a-b (0.1–10 μM) were tested on isolated liver specimens treated with lipopolysaccharide (LPS), and the levels of lactate dehydrogenase (LDH), prostaglandin (PG) E₂, and 8-iso-PGF₂α were measured. The effects of these compounds on the gene expression of the adipose tissue markers of browning, PPARα, and PPARγ, in white adipocytes, were evaluated as well. We found a significant reduction in LPS-induced LDH, PGE₂, and 8-iso-PGF₂α levels after 1a treatment. On the other hand, 1b decreased LPS-induced LDH activity. Compared to the control, 1a stimulated uncoupling protein 1 (UCP1), PR-(PRD1-BF1-RIZ1 homologous) domain containing 16 (PRDM16), deiodinase type II (DIO2), and PPARα and PPARγ gene expression, in 3T3-L1 cells. Similarly, 1b increased UCP1, DIO2, and PPARγ gene expression. 2a-b caused a reduction in the gene expression of UCP1, PRDM16, and DIO2 when tested at 10 μM. In addition, 2a-b significantly decreased PPARα gene expression. A significant reduction in PPARγ gene expression was also found after 2b treatment. The novel PPARα agonist 1a might be a promising lead compound and represents a valuable pharmacological tool for further assessment. The PPARγ agonist 1b could play a minor role in the regulation of inflammatory pathways.

Extracellular vesicles (EVs) are a heterogenous population of plasma membrane-surrounded particles that are released in the extracellular milieu by almost all types of living cells. EVs are key players in intercellular crosstalk, both locally and systemically, given that they deliver their cargoes (consisting of proteins, lipids, mRNAs, miRNAs, and DNA fragments) to target cells, crossing biological barriers. Those mechanisms further trigger a wide range of biological responses. Interestingly, EV phenotypes and cargoes and, therefore, their functions, stem from their specific parental cells. For these reasons, EVs have been proposed as promising candidates for EV-based, cell-free therapies. One of the new frontiers of cell-based immunotherapy for the fight against refractory neoplastic diseases is represented by genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes, which in recent years have demonstrated their effectiveness by reaching commercialization and clinical application for some neoplastic diseases. CAR-T-derived EVs represent a recent promising development of CAR-T immunotherapy approaches. This crosscutting innovative strategy is designed to exploit the advantages of genetically engineered cell-based immunotherapy together with those of cell-free EVs, which in principle might be safer and more efficient in crossing biological and tumor-associated barriers. In this review, we underlined the potential of CAR-T-derived EVs as therapeutic agents in tumors.