An overactivation of hepatocyte growth factor (HGF)/mesenchymal-epithelial transition factor (MET) axis promotes tumorigenesis and tumor progression in various cancer types. Research data recently evidenced that HGF/MET signaling is also involved also in the immune response, mainly modulating dendritic cells functions. In general, the pathway seems to play an immunosuppressive role, thus hypothesizing that it could constitute a mechanism of primary and acquired resistance to cancer immunotherapy. Recently, some approaches are being developed, including drug design and cell therapy to combine MET and programmed cell death receptor-1 (PD-1)/programmed cell death receptor-ligand 1 (PD-L1) inhibition. This approach could represent a new weapon in cancer therapy in the future.

Background: Identifying response markers is highly needed to guide the treatment strategy in patients with metastatic melanoma. Methods: A retrospective study was carried out in patients with unresectable/metastatic melanoma (stage IIIb–IV), treated with anti-PD-1 in the first line setting, to better explore the role and the timing of neutrophil/lymphocyte ratio (NLR) as potential biomarker of response. The relationship of NLR with inflammation-immune mediators and the underlying negative effect of raising NLR during immunotherapy, have been investigated with transcriptomic gene analysis. Results: The results confirmed previous findings that a high baseline NLR is associated with a poorer prognosis and with higher serum level of lactate dehydrogenase (LDH), regardless of the presence of brain metastases. The transcriptomic analysis showed that high baseline NLR is associated with a characteristic gene signature CCNA1, LDHA and IL18R1, which correlates with inflammation and tumorigenesis. Conversely, low baseline NLR is associated with the signature CD3, SH2D1A, ZAP70 and CD45RA, linked to the immune-activation. The genes positively associated with NLR (CD39 (ENTPD1), PTEN, MYD88, MMP9 and LDH) are involved in processes of immunosuppression, inflammation and tumor-promoting activity. Increased expression of CD39 correlated with TGFβ₂, a marker of the N2 neutrophils with immunosuppressive activity. Conclusions: These results suggest that increasing NLR is associated with an increased neutrophil population, with polarization to the N2 phenotype, and this process may be the basis for the negatively prognostic role of NLR.

Pioglitazone, a synthetic peroxisome proliferator activated receptor (PPAR-γ) ligand, is known as an antidiabetic drug included in the thiazolidinediones (TZDs) class. It regulates the lipid and glucose cell metabolism and recently a role in the inhibition of numerous cancer cell processes has been described. In our work we investigate the anti-tumor effects of pioglitazone in in vitro models of non small cell lung cancer (NSCLC) and also, we generated ex-vivo three-dimensional (3D) cultures from human lung adenocarcinoma (ADK) as a model to test drug efficacy observed in vitro. The inhibitory effect of pioglitazone on cell proliferation, apoptosis and cell invasion in a panel of human NSCLC cell lines was evaluated by multiple assays. Pioglitazone reduced proliferative and invasive abilities with an IC50 ranging between 5 and 10 μM and induced apoptosis of NSCLC cells. mRNA microarray expression profiling showed a down regulation of MAPK, Myc and Ras genes after treatment with pioglitazone; altered gene expression was confirmed by protein analysis in a dose-related reduction of survivin and phosphorylated proteins levels of MAPK pathway. Interestingly mRNA microarray analysis showed also that pioglitazone affects TGFβ pathway, which is important in the epithelial-to-mesenchimal transition (EMT) process, by down-regulating TGFβR1 and SMAD3 mRNA expression. In addition, extracellular acidification rate (ECAR) and a proportional reduction of markers of altered glucose metabolism in treated cells demonstrated also cell bioenergetics modulation by pioglitazone. Data indicate that PPAR-γ agonists represent an attractive treatment tool and by suppression of cell growth (in vitro and ex vivo models) and of invasion via blockade of MAPK cascade and TGFβ/SMADs signaling, respectively, and its role in cancer bioenergetics and metabolism indicate that PPAR-γ agonists represent an attractive treatment tool for NSCLC.

Resistance biomarkers are needed to identify patients with advanced melanoma obtaining a response to ICI treatment and developing resistance later. We searched a combination of molecular signatures of response to ICIs in patients with metastatic melanoma. In a retrospective study on patients with metastatic melanoma treated with an anti-PD-1 agent carried out at Istituto Nazionale Tumori—IRCCS—Fondazione “G. Pascale”, Naples, Italy. We integrated a whole proteome profiling of metastatic tissue with targeted transcriptomics. To assess the prognosis of patients according to groups of low and high risk, we used PFS and OS as outcomes. To identify the proteins and mRNAs gene signatures associated with the patient’s response groups, the discriminant analysis for sparse data performed via partial least squares procedure was performed. Tissue samples from 22 patients were analyzed. A combined protein and gene signature associated with poorer response to ICI immunotherapy in terms of PFS and OS was identified. The PFS and OS Kaplan–Meier curves were significantly better for patients with high expression of the protein signature compared to patients with low expression of the protein signature and who were high-risk (Protein: HR = 0.023, 95% CI: 0.003–0.213; p < 0.0001. Gene: HR = 0.053, 95% CI: 0.011–0.260; p < 0.0001). The Kaplan–Meier curves showed that patients with low-risk gene signatures had better PFS (HR = 0 0.221, 95% CI: 0.071–0.68; p = 0.007) and OS (HR = 0.186, 95% CI: 0.05–0.695; p = 0.005). The proteomic and transcriptomic combined analysis was significantly associated with the outcomes of the anti-PD-1 treatment with a better predictive value compared to a single signature. All the patients with low expression of protein and gene signatures had progression within 6 months of treatment (median PFS = 3 months, 95% CI: 2–3), with a significant difference vs. the low-risk group (median PFS = not reached; p < 0.0001), and significantly poorer survival (OS = 9 months, 95% CI: 5–9) compared to patients with high expression of protein and gene signatures (median OS = not reached; p < 0.0001). We propose a combined proteomic and transcriptomic signature, including genes involved in pro-tumorigenic pathways, thereby identifying patients with reduced probability of response to immunotherapy with ICIs for metastatic melanoma.

Purpose of Review: The treatment strategy for BRAF-mutated melanoma remains unsatisfactory, although the advent of immune checkpoint inhibition has improved the prognosis of advanced melanoma. This article reports current evidence on the efficacy and safety of sequential immunotherapy with targeted therapy in patients with BRAF-mutated melanoma. It discusses criteria for the use of available options in clinical practice. Recent Findings: Targeted therapy provides rapid disease control in a relatively high proportion of patients, although the development of secondary resistance limits the duration of responses; in contrast, immunotherapy may induce slow but more durable responses in a subset of patients. Summary: Therefore, the identification of a combination strategy for the use of these therapies seems a promising perspective. Currently, inconsistent data have been obtained, but most studies indicate that the administration of BRAFi/MEKi prior to immune checkpoint inhibitors appears to reduce the efficacy of immunotherapy. On the contrary, several clinical and real-life studies suggest that frontline immunotherapy with subsequent targeted therapy may be associated with better tumor control than immunotherapy alone. Larger clinical studies are ongoing to confirm the efficacy and safety of this sequencing strategy for treating BRAF-mutated melanoma with immunotherapy followed by targeted therapy.

Background: Nivolumab is an anti-PD1 antibody that has dramatically improved metastatic melanoma patients’ outcomes. Nevertheless, many patients are resistant to PD-1 inhibition, occasionally experiencing severe off-target immune toxicity. In addition, no robust and reproducible biomarkers have yet been validated to identify the correct selection of patients who will benefit from anti-PD-1 treatment avoiding unwanted side effects. However, the strength of CD26 expression on CD4⁺ T lymphocytes permits the characterization of three subtypes with variable degrees of responsiveness to tumors, suggesting that the presence of CD26-expressing T cells in patients might be a marker of responsiveness to PD-1-based therapies. Methods: The frequency distribution of peripheral blood CD26-expressing cells was investigated employing multi-parametric flow cytometry in 69 metastatic melanoma patients along with clinical characteristics and blood count parameters at baseline (W0) and compared to 20 age- and sex-matched healthy controls. Percentages of baseline CD4⁺CD26^high T cells were correlated with the outcome after nivolumab treatment. In addition, the frequency of CD4⁺CD26^high T cells at W0 was compared with those obtained after 12 weeks (W1) of therapy in a sub-cohort of 33 patients. Results: Circulating CD4⁺CD26^high T cells were significantly reduced in melanoma patients compared to healthy subjects (p = 0.001). In addition, a significant association was observed between a low baseline percentage of CD4⁺CD26^high T cells (< 7.3%) and clinical outcomes, measured as overall survival (p = 0.010) and progression-free survival (p = 0.014). Moreover, patients with clinical benefit from nivolumab therapy had significantly higher frequencies of circulating CD4⁺CD26^high T cells than patients with non-clinical benefit (p = 0.004) at 12 months. Also, a higher pre-treatment proportion of circulating CD4⁺CD26^high T cells was correlated with Disease Control Rate (p = 0.014) and best Overall Response Rate (p = 0.009) at 12 months. Interestingly, after 12 weeks (W1) of nivolumab treatment, percentages of CD4⁺CD26^high T cells were significantly higher in comparison with the frequencies measured at W0 (p < 0.0001), aligning the cell counts with the ranges seen in the blood of healthy subjects. Conclusions: Our study firstly demonstrates that peripheral blood circulating CD4⁺CD26^high T lymphocytes represent potential biomarkers whose perturbations are associated with reduced survival and worse clinical outcomes in melanoma patients.