Endothelial-to-mesenchymal transition (EndMT) is a dynamic cellular process characterized by a phenotypic-functional switch of cells from endothelial-to-mesenchymal traits. Many studies have identified EndMT as a key driver of tumor growth and progression. EndMT supports tumor cell proliferation by creating a tumor microenvironment that facilitates cancer cell survival. Notably, EndMT is an important source of cancer-associated fibroblasts, leads to immune dysregulation and immune escape, and supports metastasis and resistance to therapy. Hence, understanding the intricate relationship between EndMT and cancer progression offers exciting new avenues for therapeutic intervention. This review aims to describe the central role of EndMT in tumor progression, highlighting the molecular mechanisms underlying this endothelial alteration and its significant involvement at all stages of tumor progression.

Gastrointestinal stromal tumors (GISTs) are rare, mesenchymal tumors of the gastrointestinal tract, characterized by either KIT or PDGFRA mutation in about 85% of cases. KIT/PDGFRA wild type gastrointestinal stromal tumors (wtGIST) account for the remaining 15% of GIST and represent an unmet medical need: their prevalence and potential medical vulnerabilities are not completely defined, and effective therapeutic strategies are still lacking. In this study we set a patient-derived preclinical model of wtGIST to investigate their phenotypic features, along with their susceptibility to cellular immunotherapy with cytokine-induced killer lymphocytes (CIK) and interferons (IFN). We generated 11 wtGIST primary cell lines (wtGISTc). The main CIK ligands (MIC A/B; ULBPs), along with PD-L1/2, were expressed by wtGISTc and the expression of HLA-I molecules was preserved. Patient-derived CIK were capable of intense killing in vitro against wtGISTc resistant to both imatinib and sunitinib. We found that CIK produce a high level of granzyme B, IFNα and IFNγ. CIK-conditioned supernatant was responsible for part of the observed tumoricidal effect, along with positive bystander modulatory activities enhancing the expression of PD-L1/2 and HLA-I molecules. IFNα, but not In, had direct antitumor effects on 50% (4/8) of TKI-resistant wtGISTc, positively correlated with the tumor expression of IFN receptors. wtGIST cells that survived IFNα were still sensitive to CIK immunotherapy. Our data support the exploration of CIK immunotherapy in clinical studies for TKI-resistant wtGIST, proposing reevaluation for IFNα within this challenging setting.

The outbreak of novel coronavirus disease 2019 (COVID-19) has exacted a disproportionate toll on cancer patients. The effects of anticancer treatments and cancer patients’ characteristics shared significant responsibilities for this dismal outcome; however, the underlying immunopathological mechanisms are far from being completely understood. Indeed, despite their different etiologies, SARS-CoV-2 infection and cancer unexpectedly share relevant immunobiological connections. In the pathogenesis and natural history of both conditions, there emerges the centrality of the immune response, orchestrating the timed appearance, functional and dysfunctional roles of multiple effectors in acute and chronic phases. A significant number (more than 600) of observational and interventional studies have explored the interconnections between COVID-19 and cancer, focusing on aspects as diverse as psychological implications and prognostic factors, with more than 4000 manuscripts published so far. In this review, we reported and discussed the dynamic behavior of the main cytokines and immune system signaling pathways involved in acute vs. early, and chronic vs. advanced stages of SARS-CoV-2 infection and cancer. We highlighted the biological similarities and active connections within these dynamic disease scenarios, exploring and speculating on possible therapeutic crossroads from one setting to the other.

Advanced-stage sarcomas pose a major challenge in oncology, as they are often resistant to conventional therapies and associated with poor prognosis. CAR-based cellular immunotherapy is emerging as a very promising therapeutic option; however, clinically relevant animal models are urgently needed to accelerate the clinical development of these approaches. B7-H3 molecule, due to its low expression in normal tissue, high prevalence in multiple human cancers, and association with cancer stemness and aggressiveness, represents one of the most attractive targets for CAR-immunotherapy. In this study, we established a preclinical cellular immunotherapy platform based on canine cytokine-induced killer cells (CIK) redirected by an antihuman B7-H3 CAR against canine sarcoma cells and 3D sarcoma spheroids. B7-H3 was consistently detected across all analyzed canine sarcoma subtypes, including osteosarcoma, soft tissue sarcoma, and hemangiosarcoma, although with variable levels of expression intensity. We successfully generated canine B7-H3-CAR.CIK, achieving a mean CAR expression of 39% ± 2 with an immune phenotype unmodified (NTD) control (CD3 = 92% ± 3, CD8 = 87% ± 7; CD4 = 49% ± 5; CD5 = 77% ± 0.1; NKp46 = 83% ± 5). Canine B7-H3-CAR.CIK efficiently killed canine sarcoma cell lines compared with NTD.CIK, even at low effector/target (E/T) ratios (B7-H3-CAR.CIK: 45% vs 8%; E:T 1:1; 48 h; N = 7, n = 8; p < 0.0001), and demonstrated significant cytotoxicity against 3D sarcoma spheroids (58% vs 13%; E:T 2:1; 48 h; N = 3, n = 4; p < 0.01). Our findings establish a clinically relevant and translationally valuable platform for evaluating B7-H3-CAR.CIK therapy in dogs with incurable sarcomas, providing a bridge toward the development of novel CAR-based immunotherapies for human incurable sarcomas.