Irma Airoldi

Lung cancer is classified as either Non-Small Cell (NSCLC) and Small Cell Lung Cancer (SCLC) and still represents the leading cause of cancer-related mortality worldwide. Prognosis of NSCLC and SCLC patients is grim; thus, novel therapies are needed. In this context, plant-derived compounds, such as olive leaf extract (OLE), recently attracted much interest for their anti-cancer properties. We investigated the impact of OLE on cell proliferation and apoptosis (by flow cytometry) and migration (by scratch test and transwell assay) of NSCLC and SCLC cell lines, underlying the mechanisms involved. Synergistic effects with cisplatin were also evaluated. OLE differentially impaired cell proliferation and induced apoptosis in LC cell lines. Notably, such effects were higher in SCLC than in NSCLC cell lines. Further analyses were performed on GLC-1 and SKMES cells, identified as OLE-sensitive and OLE-resistant models, respectively. Indeed, OLE triggered the intrinsic apoptotic pathway by activating cleaved caspase-9, -3 and -7, and induced DNA damage response and cellular stress molecules in GLC-1 cells only. In contrast, OLE affected migratory capacity of SKMES cell line and modulated stress adaptation and survival pathways. Finally, OLE synergized with cisplatin in the induction of apoptosis in GLC-1 cells. OLE exerted multiple anti-tumor effects on LC cells in vitro. Its ability to enhance cisplatin-induced apoptosis supports further investigation of OLE as a potential dietary adjunct to chemotherapy. Although OLE has an established safety profile, in vivo studies are required to validate its efficacy, and assess potential interactions with chemotherapeutic drugs before any clinical application.

Aim: Extracellular vesicles (EVs) mediate cell-to-cell communication and co-contribute in cancer progression and modulation of immune responses. The aim of this work was to characterize the phenotype and function of EVs isolated from the peripheral blood (PB) of multiple myeloma (MM) patients, with particular attention to adenosinergic ectoenzymes. Methods: EVs were isolated by centrifugation of PB plasma samples from newly diagnosed (ND) MM patients and healthy donors (HD). EVs were characterized by nanoparticle tracking analysis (NTA). Flow cytometry was used to assess the expression of CD138 (a tumor-associated antigen), nicotinamide phosphoribosyltransferase/pre-B cell colony enhancing factor (NAMPT/PBEF1), and adenosinergic ectoenzymes CD38, CD39, CD203a, and CD73. Functional studies were performed by assessing T-cell proliferation in vitro using carboxyfluorescein succinimidyl ester (CFSE) dilution and flow cytometry, with or without EVs to the culture. Results: The PB EVs size was comparable between MM patients and HDs, whereas EV concentration was significantly higher in MM patients. EVs from MM patients expressed higher levels of CD138, PBEF, CD38, and CD73 than those from HDs. In addition, CD138+ EVs from MM patients expressed higher levels of PBEF, CD38, CD39, and CD73 than CD138- counterparts. Finally, MM-derived EVs inhibited T-cell proliferation in vitro. This inhibition correlated with the expression of CD138 and CD203a. Conclusion: This study provides the first phenotypic and functional characterization of EVs obtained from the PB of MM patients. The presence of functional adenosinergic molecules may represent a novel immune-escape mechanism operating at distant sites. Nonetheless, further studies are required to define specific contributions of adenosinergic ectoenzymes and other immune-regulatory mechanisms.

Modern scientific research increasingly views olive leaf extract (OLE) not merely as a simple supplement, but as a sophisticated chemical orchestra where a wide array of phytochemicals works in natural harmony to provide therapeutic benefits. While olive oil is the most famous product of the Olea europaea tree, it is important to emphasize that the leaves are actually a far richer and more concentrated reservoir of bioactive molecules, often containing phenolic levels several times higher than those found in the fruit or oil. This whole plant extract often proves more biologically effective than isolated compounds because its components target multiple cellular pathways simultaneously. Many beneficial effects have been ascribed to OLE including anti-inflammatory, anti-oxidant, anti-microbial, anti-viral, neuroprotective, and anti-tumoral effects. In this review, we focused on the latter activity, especially in the field of pediatric tumors such as acute leukemias and neuroblastoma. This issue was discussed starting from the definition of OLE and its components describing the main biological activities, passing through the OLE roles on the immune system, moving on to the anti-cancer functions, and ending with future perspectives.

γδ T lymphocytes and NK cells are effective to kill tumors or viral-infected cells avoiding graft versus host disease (GvHD), thus they have attracted high interest as potential tool for adoptive cell therapy. We generated an advanced therapy medicinal product (ATMP) composed of mature γδ T and NK cells to provide an innovative tool to protect patients against tumor relapse and life-threatening infection after haploidentical hematopoietic stem cell transplantation. The ATMP was manufactured and validated in a GMP facility and was obtained from leukapheresis stimulated with zoledronic acid and IL-2, afterward depleted of αβ T lymphocytes using the CliniMACS Prodigy. The ATMP is characterized by high homogeneity, cell viability, cytotoxic abilities, stability after cryogenic preservation, and it was virtually free of αβ T and B lymphocytes. Both NK and γδ T cells were activated and characterized by high expression of cytotoxic and activating receptors including NKG2D, CD16, NKp30, NKp44, and NKp46. Furthermore, γδ T lymphocytes and NK cells were cytotoxic against myeloid leukemia or neuroblastoma cells. In conclusion, we implemented a novel ATMP to be shortly translated into clinical practice, which may be used in the post-transplant phase as efficacious immunotherapy in neuroblastoma and leukemic pediatric patients.

Background: Anti-GD2 monoclonal antibody effectively treats high-risk neuroblastoma (HR-NB) by recruiting NK cells for antibody-dependent cellular cytotoxicity (ADCC). We recently developed a cell product containing mature, cytotoxic γδ T and NK cells (GADEKILL), and its potential use as a novel immunotherapy for HR-NB has been investigated. Methods: The GADEKILL γδ T and NK cells were analyzed by flow cytometry for the expression of activating and inhibitory receptors and for cytotoxicity against NB, both with and without dinutuximab-β, at a 1:1 effector-to-target ratio. NB cell lines with high and low/absent GD2 expression, as well as patient-derived 3D tumor spheres, all GD2-expressing, were used as targets. Comparative analyses were performed between GADEKILL NK and purified NK cells obtained from the same donor leukapheresis. Furthermore, a panel of NB cell lines was tested for the expression of B7H6 (i.e., NKp30 ligand), Human influenza hemagglutinin-tag (HA-TAG) and calreticulin (i.e., NKp46 ligands), and butyrophilin (BTN)2A1 and BTN3A1/2/3 (i.e., TCRVδ2 ligands), and the impact on GADEKILL cytotoxicity was assessed. Results: Compared to their purified counterparts, GADEKILL NK cells showed: (i) higher expression of NKp30 and NKp44 and lower expression of CD16 and NKG2D, (ii) greater cytotoxicity (CD107a ⁺ ) against GD2 ⁻ NB cells, (iii) stronger induction of lysis in low GD2-expressing NB cells and patient-derived 3D tumor spheres, and (iv) comparable ADCC. In addition, both γδ T and NK cells degranulated and consistently induced lysis in a panel of NB cell lines and patient-derived 3D tumor spheres expressing B7H6, calreticulin, HA-TAG, BTN2A1, and BTN3A1/2/3 consistently. Finally, NB cell lysis positively correlated with B7H6 and BTN2A1, and B7H6-blocking experiments revealed a significant decrease in target cell lysis when cells highly expressing B7H6 were used as targets. Conclusions: Our study demonstrated the potential antineuroblastoma activity of the GADEKILL, supporting its therapeutic use, particularly in the context of relapsed/refractory R/R HR-NB with low GD2 expression.

Background/Objectives: Several studies reported that olive leaf extract (OLE) may exert potent anti-cancer activities against human solid and hematological tumors. Such effects are mostly related to the polyphenol oleuropein and its derivatives, which are highly concentrated in OLE. Here, we investigated the anti-tumor effects of OLE in vitro against human acute leukemia and lymphoma cells. Methods: Cell proliferation and apoptosis have been evaluated by flow cytometry (using CFSE and Annexin-V/7AAD, respectively) in the presence or absence of OLE at different concentrations and in combination with or without chemotherapeutic drugs. Cellular pathways have been analyzed using antibody arrays. Results: OLE inhibited cell proliferation and induced apoptosis in B-acute lymphoblastic leukemia (B-ALL) and, to a lesser extent, in lymphomas and acute myeloid leukemia (AML) cell lines. Notably, OLE-induced apoptosis also occurs in primary leukemic blasts from B-ALL patients, both at diagnosis and at relapse, but only marginally in primary AML blasts. The expression and phosphorylation of proteins involved in the induction of apoptosis were modulated by OLE in B-ALL, whereas modest effects were observed in AML. Interestingly, some proteins were modulated in opposite ways in B-ALL and AML, potentially explaining their different responses to OLE. Finally, a synergistic and additive effect was observed for OLE in combination with cytarabine, but not with cyclophosphamide. Conclusions: We may envisage that OLE may be used as a food supplement in B-ALL patients treated with cytarabine, taking advantage of the potentiated effect of chemotherapy, without additional side effects.

The role of extracellular vesicles has been extensively studied in physiological and pathological conditions, and growing evidence has pinpointed them as key players in tumor progression, regulation of the metastatic niche, and modulation of anti-tumor immune responses. Indeed, a dynamic transfer of extracellular vesicles between cancer cells and immunological or non-immunological cells homing in the tumor microenvironment exists, and the balance between their release by cancer cells and by normal cells determines cancer progression. Here, we focused on the role of extracellular vesicles in the dysregulation of the bone marrow environment in pediatric tumors such as acute leukemias and neuroblastomata, whose poor prognosis is strictly related to the involvement of such anatomical site. Acute leukemias arise from bone marrow progenitors, whereas approximately 50% of neuroblastoma patients have bone marrow metastases at diagnosis. Thus, here, we discuss the mechanisms underlying the bone marrow dysregulation in pediatric acute leukemias and neuroblastomata with particular emphasis on the involvement of extracellular vesicles.

HLA-G is an HLA-class Ib molecule that is involved in the establishment of tolerance at the maternal/fetal interface during pregnancy. The expression of HLA-G is highly restricted in adults, but the de novo expression of this molecule may be observed in different hematological and solid tumors and is related to cancer progression. Indeed, tumor cells expressing high levels of HLA-G are able to suppress anti-tumor responses, thus escaping from the control of the immune system. HLA-G has been proposed as an immune checkpoint (IC) molecule due to its crucial role in tumor progression, immune escape, and metastatic spread. We here review data available in the literature in which the interaction between HLA-G and other IC molecules is reported, in particular PD-1, CTLA-4, and TIM-3, but also IDO and TIGIT. Clinical trials using monoclonal antibodies against HLA-G and other IC are currently ongoing with cancer patients where antibodies and inhibitors of PD-1 and CTLA-4 showed encouraging results. With this background, we may envisage that combined therapies using antibodies targeting HLA-G and another IC may be successful for clinical purposes. Indeed, such immunotherapeutic protocols may achieve a better rescue of effective anti-tumor immune response, thus improving the clinical outcome of patients.