Development of strong immune evasion has been traditionally associated with the late stages of solid tumor progression, since advanced cancers are more likely to have reached the third phase of the ...immunoediting process. However, by integrating a variety of approaches, evidence for active immune escape mechanisms has been found even in the pre-invasive lesions that later progress to the main NSCLC histotypes. Pre-invasive lesions of adenocarcinoma (LUAD) and of squamous cell carcinoma (LUSC) can show impaired antigen presentation, loss of heterozygosity at the Human Leukocyte Antigen (HLA) region, neoantigen silencing, activation of immune checkpoints, altered TH1/TH2 cytokine ratios, and immune contexture evolution. Analysis of large panels of LUAD vs. LUSC, of early stage NSCLC vs. normal lung tissue, of specific molecular subsets of NSCLC, and of distinct regions within the same tumor, indicates that all these processes of immune escape continue to evolve in the invasive stage of NSCLC, are associated with inter- and intra-tumor heterogeneity, and contribute to resistance to therapy by immune checkpoint blockade (ICB). In this review, we will discuss the most recent evidence on immune escape mechanisms developing from the precursor to invasive stage in NSCLC, and the contribution of immune evasion to resistance to ICB in lung cancer.
Hyperprogression (HP), a paradoxical boost in tumor growth, was described in a subset of patients treated with immune checkpoint inhibitors (ICI). Neither clinicopathologic features nor biological ...mechanisms associated with HP have been identified.
Among 187 patients with non-small cell lung cancer (NSCLC) treated with ICI at our institute, cases with HP were identified according to clinical and radiologic criteria. Baseline histologic samples from patients treated with ICI were evaluated by IHC for myeloid and lymphoid markers. T-cell-deficient mice, injected with human lung cancer cells and patient-derived xenografts (PDX) belonging to specific mutational subsets, were assessed for tumor growth after treatment with antibodies against mouse and human programmed death receptor-1 (PD-1). The immune microenvironment was evaluated by flow cytometry and IHC.
Among 187 patients, 152 were evaluable for clinical response. We identified four categories: 32 cases were defined as responders (21%), 42 patients with stable disease (27.7%), 39 cases were defined as progressors (25.7%), and 39 patients with HP (25.7%). Pretreatment tissue samples from all patients with HP showed tumor infiltration by M2-like CD163
CD33
PD-L1
clustered epithelioid macrophages. Enrichment by tumor-associated macrophages (TAM) was observed, even in tumor nodules from immunodeficient mice injected with human lung cancer cells and with PDXs. In these models, tumor growth was enhanced by treatment with anti-PD-1 but not anti-PD-1 F(ab)
fragments.
These results suggest a crucial role of TAM reprogramming, upon Fc receptor engagement by ICI, eventually inducing HP and provide clues on a distinctive immunophenotype potentially able to predict HP.
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There is widespread interest in macrophages as a therapeutic target in cancer. Here, we demonstrate that trabectedin, a recently approved chemotherapeutic agent, induces rapid apoptosis exclusively ...in mononuclear phagocytes. In four mouse tumor models, trabectedin caused selective depletion of monocytes/macrophages in blood, spleens, and tumors, with an associated reduction of angiogenesis. By using trabectedin-resistant tumor cells and myeloid cell transfer or depletion experiments, we demonstrate that cytotoxicity on mononuclear phagocytes is a key component of its antitumor activity. Monocyte depletion, including tumor-associated macrophages, was observed in treated tumor patients. Trabectedin activates caspase-8-dependent apoptosis; selectivity for monocytes versus neutrophils and lymphocytes is due to differential expression of signaling and decoy TRAIL receptors. This unexpected property may be exploited in different therapeutic strategies.
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► Trabectedin is a recently approved antitumor agent of marine origin ► Trabectedin activates caspase-8-dependent apoptosis exclusively in myelomonocytes ► In vivo trabectedin reduces monocytes and TAM, and related angiogenesis ► Depletion of TAM is a key component of the antitumor efficacy of trabectedin
Interleukin-12 (IL-12) is a heterodimeric protein, first recovered from EBV-transformed B cell lines. It is a multifunctional cytokine, the properties of which bridge innate and adaptive immunity, ...acting as a key regulator of cell-mediated immune responses through the induction of T helper 1 differentiation. By promoting IFN-gamma production, proliferation, and cytolytic activity of natural killer and T cells, IL-12 induces cellular immunity. In addition, IL-12 induces an antiangiogenic program mediated by IFN-gamma-inducible genes and by lymphocyte-endothelial cell cross-talk. The immunomodulating and antiangiogenic functions of IL-12 have provided the rationale for exploiting this cytokine as an anticancer agent. In contrast with the significant antitumor and antimetastatic activity of IL-12, documented in several preclinical studies, clinical trials with IL-12, used as a single agent, or as a vaccine adjuvant, have shown limited efficacy in most instances. More effective application of this cytokine, and of newly identified IL-12 family members (IL-23 and IL-27), should be evaluated as therapeutic agents with considerable potential in cancer patients.
NK cells use a variety of receptors to detect abnormal cells, including tumors and their metastases. However, in the case of melanoma, it remains to be determined what specific molecular interactions ...are involved and whether NK cells control metastatic progression and/or the route of dissemination. Here we show that human melanoma cell lines derived from LN metastases express ligands for natural cytotoxicity receptors (NCRs) and DNAX accessory molecule-1 (DNAM-1), two emerging NK cell receptors key for cancer cell recognition, but not NK group 2 member D (NKG2D). Compared with cell lines derived from metastases taken from other anatomical sites, LN metastases were more susceptible to NK cell lysis and preferentially targeted by adoptively transferred NK cells in a xenogeneic model of cell therapy. In mice, DNAM-1 and NCR ligands were also found on spontaneous melanomas and melanoma cell lines. Interference with DNAM-1 and NCRs by antibody blockade or genetic disruption reduced killing of melanoma cells. Taken together, these results show that DNAM-1 and NCRs are critical for NK cell-mediated innate immunity to melanoma cells and provide a background to design NK cell-based immunotherapeutic strategies against melanoma and possibly other tumors.
Abstract
Association with hypomethylating agents is a promising strategy to improve the efficacy of immune checkpoint inhibitors-based therapy. The NIBIT-M4 was a phase Ib, dose-escalation trial in ...patients with advanced melanoma of the hypomethylating agent guadecitabine combined with the anti-CTLA-4 antibody ipilimumab that followed a traditional 3 + 3 design (NCT02608437). Patients received guadecitabine 30, 45 or 60 mg/m
2
/day subcutaneously on days 1 to 5 every 3 weeks starting on week 0 for a total of four cycles, and ipilimumab 3 mg/kg intravenously starting on day 1 of week 1 every 3 weeks for a total of four cycles. Primary outcomes of safety, tolerability, and maximum tolerated dose of treatment were previously reported. Here we report the 5-year clinical outcome for the secondary endpoints of overall survival, progression free survival, and duration of response, and an exploratory integrated multi-omics analysis on pre- and on-treatment tumor biopsies. With a minimum follow-up of 45 months, the 5-year overall survival rate was 28.9% and the median duration of response was 20.6 months. Re-expression of immuno-modulatory endogenous retroviruses and of other repetitive elements, and a mechanistic signature of guadecitabine are associated with response. Integration of a genetic immunoediting index with an adaptive immunity signature stratifies patients/lesions into four distinct subsets and discriminates 5-year overall survival and progression free survival. These results suggest that coupling genetic immunoediting with activation of adaptive immunity is a relevant requisite for achieving long term clinical benefit by epigenetic immunomodulation in advanced melanoma patients.
Gene signatures are increasingly being used to infer the immune composition of the tumor microenvironment. This strategy holds the promise for earlier detection, identification of patients at higher ...risk of progression, and for understanding therapeutic response and resistance to immunotherapy. This gene signature approach is now being integrated with information from genomic changes, gene networks, and master immunoregulatory genes, and this development can lead to identify the main determinants shaping the tumor immune landscape. A study in this issue of
indicates a way forward to discover prognostic immune-related subsets in primary melanoma and to understand major determinants impairing protective immunity in early stage of disease.
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Despite the recent breakthroughs in targeted and immunotherapy for melanoma, the overall survival rate remains low. In recent years, considerable attention has been paid to the gut microbiota and ...other modifiable patient factors (e.g., diet and body composition), though their role in influencing therapeutic responses has yet to be defined. Here, we characterized a cohort of 31 patients with unresectable IIIC-IV-stage cutaneous melanoma prior to initiation of targeted or first-line immunotherapy via the following methods: (i) fecal microbiome and metabolome via 16S rRNA amplicon sequencing and gas chromatography/mass spectrometry, respectively, and (ii) anthropometry, body composition, nutritional status, physical activity, biochemical parameters, and immunoprofiling. According to our data, patients subsequently classified as responders were obese (i.e., with high body mass index and high levels of total, visceral, subcutaneous, and intramuscular adipose tissue), non-sarcopenic, and enriched in certain fecal taxa (e.g.,
) and metabolites (e.g., anethole), which were potentially endowed with immunostimulatory and oncoprotective activities. On the other hand, non-response was associated with increased proportions of
,
,
,
,
, higher neutrophil levels (and a higher neutrophil-to-lymphocyte ratio), and higher fecal levels of butyric acid and its esters, which also correlated with decreased survival. This exploratory study provides an integrated list of potential early prognostic biomarkers that could improve the clinical management of patients with advanced melanoma, in particular by guiding the design of adjuvant therapeutic strategies to improve treatment response and support long-term health improvement.
Abstract
Background
Melanoma is the deadliest form of skin cancer and metastatic disease is associated with a significant survival rate drop. There is an urgent need for consistent tumor biomarkers ...to scale precision medicine and reduce cancer mortality. Here, we aimed to identify a melanoma-specific circulating microRNA signature and assess its value as a diagnostic tool.
Methods
The study consisted of a discovery phase and two validation phases. Circulating plasma extracellular vesicles (pEV) associated microRNA profiles were obtained from a discovery cohort of metastatic melanoma patients and normal subjects as controls. A pEV-microRNA signature was obtained using a LASSO penalized logistic regression model. The pEV-microRNA signature was subsequently validated both in a publicly available dataset and in an independent internal cohort.
Results
We identified and validated in three independent cohorts a panel of melanoma-specific circulating microRNAs that showed high accuracy in differentiating melanoma patients from healthy subjects with an area under the curve (AUC) of 1.00, 0.94 and 0.75 respectively. Investigation of the function of the pEV-microRNA signature evidenced their possible immune suppressive role in melanoma patients.
Conclusions
We demonstrate that a blood test based on circulating microRNAs can non-invasively detect melanoma, offering a novel diagnostic tool for improving standard care. Moreover, we revealed an immune suppressive role for melanoma pEV-microRNAs.
Escape of tumor cells from cell-intrinsic barrier mediated by tumor suppressors and cell-extrinsic barrier mediated by the immune system is crucial for tumorigenesis. Growing evidence suggests that ...reactivation of tumor suppressor function or restoration of anticancer immunity is promising strategy for anticancer therapy due to their high potential to combat cancer. p53, a key tumor suppressor, represses tumorigenesis by eliciting growth arrest, apoptosis or senescence in cancer cells. Here, we unravel that, apart from these cell-autonomous effects, p53 activates the innate immune response against cancer cells. Our results show that pharmacological reactivation of p53 can stimulate the expression of ULPB2, a ligand for NK cell activating receptor NKG2D in human tumor cells of different origin, which enhance the susceptibility of tumor cells to NK cell-mediated killing. The molecular mechanism controlling ULPB2 expression by p53 is neither ATM/ATR- nor caspase-dependent. Using several approaches, we identified p53 as a direct transcriptional regulator of ULBP2 and found a p53 response element within ULBP2 gene, which confers the p53 regulation. Furthermore, we demonstrated that demethylation of p53-binding region within ULBP2 gene was required for p53-dependent induction of ULPB2, which can be achieved via repression of DNA methyltransferases (DNMTs) by p53. This molecular evidence for the direct control of immunosurveillance by p53 links tumor suppressor activation to innate immune stimuli and provides a possibility to integrate cell-extrinsic and -intrinsic defenses against tumorigenesis by pharmacological activation of p53, which may increase the probability to achieve a durable therapeutic success.
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