Neuroimmunomodulatory Properties of Flavonoids and Derivates: A Potential Action as Adjuvants for the Treatment of Glioblastoma

Glioblastomas (GBMs) are tumors that have a high ability to migrate, invade and proliferate in the healthy tissue, what greatly impairs their treatment. These characteristics are associated with the complex microenvironment, formed by the perivascular niche, which is also composed of several stromal cells including astrocytes, microglia, fibroblasts, pericytes and endothelial cells, supporting tumor progression. Further microglia and macrophages associated with GBMs infiltrate the tumor. These innate immune cells are meant to participate in tumor surveillance and eradication, but they become compromised by GBM cells and exploited in the process. In this review we discuss the context of the GBM microenvironment together with the actions of flavonoids, which have attracted scientific attention due to their pharmacological properties as possible anti-tumor agents. Flavonoids act on a variety of signaling pathways, counteracting the invasion process. Luteolin and rutin inhibit NFκB activation, reducing IL-6 production. Fisetin promotes tumor apoptosis, while inhibiting ADAM expression, reducing invasion. Naringenin reduces tumor invasion by down-regulating metalloproteinases expression. Apigenin and rutin induce apoptosis in C6 cells increasing TNFα, while decreasing IL-10 production, denoting a shift from the immunosuppressive Th2 to the Th1 profile. Overall, flavonoids should be further exploited for glioma therapy.

Core Needle Biopsy Enhances the Activity of the CCL2/CCR2 Pathway in the Microenvironment of Invasive Breast Cancer

The use of core needle biopsy (CNB) as a means to verify malignancy preoperatively is a paradigm in current breast cancer care, and the risk of enhancing tumor development by this procedure has been considered insignificant. Experimental work in mice has shown preoperative biopsies to increase tumor supportive elements in the microenvironment, whereas, in humans, the impact of CNB on the host’s immunologic response has not been investigated. In this pilot study, we compared the expression of CCL2/CCR2 pathway components at the protein level in samples from CNBs to those from the corresponding resected tumors from 52 patients with primary breast cancer. We found an increased expression of CD163, CD14 and CCR2 in monocytes/macrophages and a slight decrease of CCL2 in the malignant epithelium in the tumors after the biopsy. The increased infiltration of immunosuppressive monocytes/macrophages and the decreased tumor cell CCL2 expression, presumably due to the CCR2 availability-dependent CCL2 internalization, suggest that CNB enhances the activity of the CCL2/CCR2 pathway, and this finding warrants confirmatory examination. The switch in the context-dependent role of CCL2 on the polarization of macrophages may lead to increased tumor supportive function both locally and in the peripheral immune machinery. The future directions in breast cancer should include early interventions to support the tumor surveillance of the host.

The need for tumor surveillance of children and adolescents with cancer predisposition syndromes: a retrospective cohort study in a tertiary-care children’s hospital

Expert recommendations for the management of tumor surveillance in children with a variety of cancer predisposition syndromes (CPS) are available. We aimed (1) at identifying and characterizing children who are affected by a CPS and (2) at comparing current practice and consensus recommendations of the American Association for Cancer Research workshop in 2016. We performed a database search in the hospital information system of the University Children’s Hospital for CPS in children, adolescents, and young adults and complemented this by review of electronic patients’ charts. Between January 1, 2017, and December 3, 2019, 272 patients with 41 different CPS entities were identified in 20 departments (144 [52.9%] male, 128 [47.1%] female, median age 9.1 years, range, 0.4–27.8). Three (1.1%) patients died of non-malignancy-associated complications of the CPS; 49 (18.0%) patients were diagnosed with malignancy and received regular follow-up. For 209 (95.0%) of the remaining 220 patients, surveillance recommendations were available: 30/220 (13.6%) patients received CPS consultations according to existing consensus recommendations, 22/220 (10.0%) institutional surveillance approaches were not complying with recommendations, 84/220 (38.2%) patients were seen for other reasons, and 84/220 (38.2%) were not routinely cared for. Adherence to recommendations differed extensively among CPS entities.Conclusion: The spectrum of CPS patients at our tertiary-care children’s hospital is manifold. For most patients, awareness of cancer risk has to be enhanced and current practice needs to be adapted to consensus recommendations. Offering specialized CPS consultations and establishing education programs for patients, relatives, and physicians may increase adherence to recommendations. What is Known: • A wide spectrum of rare syndromes manifesting in childhood is associated with an increased cancer risk. • For many of these syndromes, expert recommendations for management and tumor surveillance are available, although based on limited evidence. What is New: • Evaluating current practice, our data attest significant shortcomings in tumor surveillance of children and adolescents with CPS even in a tertiary-care children’s hospital. • We clearly advocate a systematic and consistent integration of tumor surveillance into daily practice.

Immune-Proteome Profiling in Classical Hodgkin Lymphoma Tumor Diagnostic Tissue

In classical Hodgkin Lymphoma (cHL), immunoediting via protein signaling is key to evading tumor surveillance. We aimed to identify immune-related proteins that distinguish diagnostic cHL tissues (=diagnostic tumor lysates, n = 27) from control tissues (reactive lymph node lysates, n = 30). Further, we correlated our findings with the proteome plasma profile between cHL patients (n = 26) and healthy controls (n = 27). We used the proximity extension assay (PEA) with the OlinkTM multiplex Immuno-Oncology panel, consisting of 92 proteins. Univariate, multivariate-adjusted analysis and Benjamini–Hochberg’s false discovery testing (=Padj) were performed to detect significant discrepancies. Proteins distinguishing cHL cases from controls were more numerous in plasma (30 proteins) than tissue (17 proteins), all Padj < 0.05. Eight of the identified proteins in cHL tissue (PD-L1, IL-6, CCL17, CCL3, IL-13, MMP12, TNFRS4, and LAG3) were elevated in both cHL tissues and cHL plasma compared with control samples. Six proteins distinguishing cHL tissues from controls tissues were significantly correlated to PD-L1 expression in cHL tissue (IL-6, MCP-2, CCL3, CCL4, GZMB, and IFN-gamma, all p ≤0.05). In conclusion, this study introduces a distinguishing proteomic profile in cHL tissue and potential immune-related markers of pathophysiological relevance.

Circulating Tumor Cells in Hepatocellular Carcinoma: A Comprehensive Review and Critical Appraisal

Hepatocellular carcinoma (HCC) is the fifth most common neoplasm and a major cause of cancer-related death worldwide. There is no ideal biomarker allowing early diagnosis of HCC and tumor surveillance in patients receiving therapy. Liquid biopsy, and particularly circulating tumor cells (CTCs), have emerged as a useful tool for diagnosis and monitoring therapeutic responses in different tumors. In the present manuscript, we evaluate the current evidence supporting the quantitative and qualitative assessment of CTCs as potential biomarkers of HCC, as well as technical aspects related to isolation, identification, and classification of CTCs. Although the dynamic assessment of CTCs in patients with HCC may aid the decision-making process, there are still many uncertainties and technical caveats to be solved before this methodology has a true impact on clinical practice guidelines. More studies are needed to identify the optimal combination of surface markers, to increase the efficiency of ex-vivo expansion of CTCs, or even to target CTCs as a potential therapeutic strategy to prevent HCC recurrence after surgery or to hamper tumor progression and extrahepatic spreading.

Emerging Roles of Long Noncoding RNAs in Immuno-Oncology

Long noncoding RNAs (lncRNAs), defined as ncRNAs no longer than 200 nucleotides, play an important role in cancer development. Accumulating research on lncRNAs offers a compelling new aspect of genome modulation, in which they are involved in chromatin remodeling, transcriptional and post-transcriptional regulation, and cross-talk with other nucleic acids. Increasing evidence suggests that lncRNAs reshape the tumor microenvironment (TME), which accounts for tumor development and progression. At the same time, the insightful findings on lncRNAs in immune recognition and evasion in tumor-infiltrating immune cells raise concerns with regard to immuno-oncology. In this review, we describe the essential characteristics of lncRNAs, elucidate functions of immune components engaged in tumor surveillance, and present some instructive examples in this new area.

Molecular Signatures of Immune Pressure and Immune Escape in Hematological Malignancies

Downmodulation of antigen presentation machinery represents a paradigm of evasion from adaptive immune surveillance. This mechanism underpins the decrease in presentation of immunogenic peptides below the activation threshold of effector T-cells. Large genomic aberrations, fine somatic mutations, epigenetic silencing and transcriptional modifications involving directly the human leukocyte antigen (HLA) region or genes encompassing antigen degradation, transportation and processing have been invoked across large cohorts of solid tumors and hematological disorders, all as a result of a common lynchpin: the established immune pressure. During tumor growth this orchestra of mechanisms shape the oncogenic landscape and facilitate the emergence of clones with lower immunogenic potential. By analyzing genomic profiles extracted from more than 7000 patients and specimens across 25 previously published cohorts encompassing both lymphoid and myeloid diseases (Table 1), we performed a large genomic study aiming to dissect the multifaceted immunoediting processes in hematological malignancies We first analyzed a broad HLA genomic dysfunction in 31 classical and non-classical loci and identified 892 somatic mutations or allelic losses in 337/6694 patients (5%). Among the different subtypes of hematological malignancies, HLA mutations were found in 16% (N=138/831) of acute lymphoblastic leukemia (ALL), 7% (N=1/14) of histiocytic disorders, 7% (N=3/43) of T-cell lymphoma, 6% (N=136/2247) of myeloid disorders, 2% (N=4/205) of multiple myeloma, 1.6% (N=55/3354) of B-cell lymphoma/chronic lymphocytic leukemia (B-LNH/CLL). Most affected loci were classical A, B and DRB1, while non-classical DPB2, F and DOA were the least interested by somatic events. Interestingly, alterations were never found in non-expressed DRB genes (DRB2-4,7-9). Among the immune genes, we focused on those which, if affected by mutations (either loss or gain of function), could possibly be associated with an immune escape signature. We identified such aberrations in 13% of cases, including CREBBP (4.5%, N=450/9875), EP300 (2.5%, N=252/9831), IRF8 (2.1%, N=166/7865), B2M (2%, N=158/7868), CD70 (1.7%, N=127/7253), TNFRSF14 (2.8%, N=221/7868), IRF4 (1.4%, N=110/7869), which were the most frequently altered. The frequency of those mutations was particularly high in B-NHL/CLL (28%) and ALL (23%). These events and HLA hits were not mutually exclusive. When analyzing the pattern of co-mutations in immune aberrant vs. non-aberrant group, we found that both lymphoid and myeloid entities were enriched in genomic abnormalities also in other immune players (e.g., NOTCH4, NFKB1, IL4R, IFNAR2, C3), emphasizing how the genomic dysfunction of the immune response may be a pathophysiological link, beyond the disease ontogenic classification. Of note is that, in MN subset, aberrations in leukemic drivers, such as: NPM1 (3% vs 16%, q=4.69E-11), JAK2 (3% vs 9%, q=1.00E-04), FLT3 (7% vs 14%, q=1.26E-04), SRSF2 (4% vs 10%, q-value=2.20E-04), DNMT3A (13% vs 21%, q=.001), TP53 (6% vs 10%, q=.009), NRAS (7% vs 12%, q=.021) were enriched in the non-immune-altered group. When accounting for the total number of mutational events, we found that this was significantly increased in immune aberrant vs. non-aberrant cases (q-value=10e-10) in both lymphoid and myeloid disorders. These findings are consistent with the hypothesis that HLA and immune defective escaping clones may arise in the context of a strong anti-tumor response, as a negative feedback to the immunoediting responsible for sculpting the tumor clonal burden. While driver hits can easily gain a fitness advantage regardless of the acquisition of immune escape signatures, immune-aberrant clones (especially if lacking more strong leukemogenic hits) would accrue subclonal alterations as a result of evasion from tumor surveillance, promoting growth only when opposing immune response. In analogy with solid cancers, our results show that also in hematological malignancies, the biology underpinning immune escape mechanisms is intimately related to the processes of immunoediting and may shape malignant clonal progression. In this setting, mutations in determinants of immune responsiveness might constitute markers of operative tumor surveillance. Figure 1 Figure 1. Disclosures Maciejewski: Novartis: Consultancy; Bristol Myers Squibb/Celgene: Consultancy; Regeneron: Consultancy; Alexion: Consultancy.

Genetic Variants in Patients with Multiple Head and Neck Paragangliomas: Dilemma in Management

Multiple head and neck paragangliomas (HNPGLs) are neuroendocrine tumors of a mostly benign nature that can be associated with a syndrome, precipitated by the presence of a germline mutation. Familial forms of the disease are usually seen with mutations of SDHx genes, especially the SDHD gene. SDHB mutations are predisposed to malignant tumors. We found 6 patients with multiple tumors amongst 30 patients with HNPGLs during the period of 2016 to 2021. We discuss the phenotypic and genetic patterns in our patients with multiple HNPGLs and explore the management possibilities related to the disease. Fifty percent of our patients had incidental findings of HNPGLs. Twenty-one biochemically silent tumors were found. Four patients had germline mutations, and only one had a positive family history. Three out of five underwent surgery without permanent complications. Preventative measures (genetic counselling and tumor surveillance) represent the gold standard in effectively controlling the disease in index patients and their relatives. In terms of treatment, apart from surgical and radiotherapeutic interventions, new therapeutic measures such as gene targeted therapy have contributed very sparsely. With the lack of standardized protocols, management of patients with multiple HNPGLs still remains very challenging, especially in those with sporadic or malignant forms of the disease.