Comprehensive genomic profiling on metastatic Melanoma: results from a network screening from 7 Italian Cancer Centres.

BACKGROUND: The current therapeutic algorithm for Advanced Stage Melanoma comprises of alternating lines of Targeted and Immuno-therapy, mostly via Immune-Checkpoint blockade. While Comprehensive Genomic Profiling of solid tumours has been approved as a companion diagnostic, still no approved predictive biomarkers are available for Melanoma aside from BRAF mutations and the controversial Tumor Mutational Burden. This study presents the results of a Multi-Centre Observational Clinical Trial of Comprehensive Genomic Profiling on Target and Immuno-therapy treated advanced Melanoma. METHODS: 82 samples, collected from 7 Italian Cancer Centres of FFPE-archived Metastatic Melanoma and matched blood were sequenced via a custom-made 184-gene amplicon-based NGS panel. Sequencing and bioinformatics analysis was performed at a central hub. Primary analysis was carried out via the Ion Reporter framework. Secondary analysis and Machine Learning modelling comprising of uni and multivariate, COX/Lasso combination, and Random Forest, was implemented via custom R/Python scripting. RESULTS: The genomics landscape of the ACC-mela cohort is comparable at the somatic level for Single Nucleotide Variants and INDELs aside a few gene targets. All the clinically relevant targets such as BRAF and NRAS have a comparable distribution thus suggesting the value of larger scale sequencing in melanoma. No comparability is reached at the CNV level due to biotechnological biases and cohort numerosity. Tumour Mutational Burden is slightly higher in median for Complete Responders but fails to achieve statistical significance in Kaplan-Meier survival analysis via several thresholding strategies. Mutations on PDGFRB, NOTCH3 and RET were shown to have a positive effect on Immune-checkpoint treatment Overall and Disease-Free Survival, while variants in NOTCH4 were found to be detrimental for both endpoints. CONCLUSIONS: The results presented in this study show the value and the challenge of a genomics-driven network trial. The data can be also a valuable resource as a validation cohort for Immunotherapy and Target therapy genomic biomarker research.

Reversing vemurafenib-resistance in primary melanoma cells by combined romidepsin and type I IFN treatment through blocking of tumorigenic signals and induction of immunogenic effects.

BRAFV600 mutations are the most common oncogenic alterations in melanoma cells, supporting proliferation, invasion, metastasis and immune evasion. In patients, these aberrantly activated cellular pathways are inhibited by BRAFi whose potent antitumor effect and therapeutic potential are dampened by the development of resistance. Here, by using primary melanoma cell lines, generated from lymph node lesions of metastatic patients, we show that the combination of two FDA-approved drugs, the histone deacetylate inhibitor (HDCAi) romidepsin and the immunomodulatory agent IFN-α2b, reduces melanoma proliferation, long-term survival and invasiveness and overcomes acquired resistance to the BRAFi vemurafenib (VEM). Targeted resequencing revealed that each VEM-resistant melanoma cell line and the parental counterpart are characterized by a distinctive and similar genetic fingerprint, shaping the differential and specific antitumor modulation of MAPK/AKT pathways by combined drug treatment. By using RNA-sequencing and functional in vitro assays, we further report that romidepsin-IFN-α2b treatment restores epigenetically silenced immune signals, modulates MITF and AXL expression and induces both apoptosis and necroptosis in sensitive and VEM-resistant primary melanoma cells. Moreover, the immunogenic potential of drug-treated VEM-resistant melanoma cells results significantly enhanced, given the increased phagocytosis rate of these cells by dendritic cells, which in turn exhibit also a selective down-modulation of the immune checkpoint TIM-3. Overall, our results provide evidence that combined epigenetic-immune drugs can overcome VEM resistance of primary melanoma cells by oncogenic and immune pathways reprogramming, and pave the way for rapidly exploiting this combination to improve BRAFi-resistant metastatic melanoma treatment, also via reinforcement of immune checkpoint inhibitor therapy.

Targeting of PDGF-C/NRP-1 autocrine loop as a new strategy for counteracting the invasiveness of melanoma resistant to braf inhibitors.

Melanoma resistance to BRAF inhibitors (BRAFi) is often accompanied by a switch from a proliferative to an invasive phenotype. Therefore, the identification of signaling molecules involved in the development of metastatic properties by resistant melanoma cells is of primary importance. We have previously demonstrated that activation of neuropilin-1 (NRP-1) by platelet-derived growth factor (PDGF)-C confers melanoma cells with an invasive behavior similar to that of BRAFi resistant tumors. Aims of the present study were to evaluate the role of PDGF-C/NRP-1 autocrine loop in the acquisition of an invasive and BRAFi-resistant phenotype by melanoma cells and the effect of its inhibition on drug resistance and extracellular matrix (ECM) invasion. Furthermore, we investigated whether PDGF-C serum levels were differentially modulated by drug treatment in metastatic melanoma patients responsive or refractory to BRAFi as single agents or in combination with MEK inhibitors (MEKi). The results indicated that human melanoma cells resistant to BRAFi express higher levels of PDGF-C and NRP-1 as compared to their susceptible counterparts. Overexpression occurs early during development of drug resistance and contributes to the invasive properties of resistant cells. Accordingly, silencing of NRP-1 or PDGF-C reduces tumor cell invasiveness. Analysis of PDGF-C in the serum collected from patients treated with BRAFi or BRAFi+MEKi, showed that in responders PDGF-C levels decrease after treatment and raise again at tumor progression. Conversely, in non-responders treatment does not affect PDGF-C serum levels. Thus, blockade of NRP-1 activation by PDGF-C might represent a new therapeutic approach to counteract the invasiveness of BRAFi-resistant melanoma.

Identification of Dihydrolipoamide Dehydrogenase as Potential Target of Vemurafenib-Resistant Melanoma Cells.

BACKGROUND: Despite recent improvements in therapy, the five-year survival rate for patients with advanced melanoma is poor, mainly due to the development of drug resistance. The aim of the present study was to investigate the mechanisms underlying this phenomenon, applying proteomics and structural approaches to models of melanoma cells. METHODS: Sublines from two human (A375 and SK-MEL-28) cells with acquired vemurafenib resistance were established, and their proteomic profiles when exposed to denaturation were identified through LC-MS/MS analysis. The pathways derived from bioinformatics analyses were validated by in silico and functional studies. RESULTS: The proteomic profiles of resistant melanoma cells were compared to parental counterparts by taking into account protein folding/unfolding behaviors. Several proteins were found to be involved, with dihydrolipoamide dehydrogenase (DLD) being the only one similarly affected by denaturation in all resistant cell sublines compared to parental ones. DLD expression was observed to be increased in resistant cells by Western blot analysis. Protein modeling analyses of DLD's catalytic site coupled to in vitro assays with CPI-613, a specific DLD inhibitor, highlighted the role of DLD enzymatic functions in the molecular mechanisms of BRAFi resistance. CONCLUSIONS: Our proteomic and structural investigations on resistant sublines indicate that DLD may represent a novel and potent target for overcoming vemurafenib resistance in melanoma cells.

Role of VEGFR-1 in melanoma acquired resistance to the BRAF inhibitor vemurafenib.

The vascular endothelial growth factor receptor-1 (VEGFR-1) is a tyrosine kinase receptor frequently expressed in melanoma. Its activation by VEGF-A or placental growth factor (PlGF) promotes tumour cell survival, migration and invasiveness. Moreover, VEGFR-1 stimulation contributes to pathological angiogenesis and induces recruitment of tumour-associated macrophages. Since melanoma acquired resistance to BRAF inhibitors (BRAFi) has been associated with activation of pro-angiogenic pathways, we have investigated VEGFR-1 involvement in vemurafenib resistance. Results indicate that human melanoma cells rendered resistant to vemurafenib secrete greater amounts of VEGF-A and express higher VEGFR-1 levels compared with their BRAFi-sensitive counterparts. Transient VEGFR-1 silencing in susceptible melanoma cells delays resistance development, whereas in resistant cells it increases sensitivity to the BRAFi. Consistently, enforced VEGFR-1 expression, by stable gene transfection in receptor-negative melanoma cells, markedly reduces sensitivity to vemurafenib. Moreover, melanoma cells expressing VEGFR-1 are more invasive than VEGFR-1 deficient cells and receptor blockade by a specific monoclonal antibody (D16F7 mAb) reduces extracellular matrix invasion triggered by VEGF-A and PlGF. These data suggest that VEGFR-1 up-regulation might contribute to melanoma progression and spreading after acquisition of a drug-resistant phenotype. Thus, VEGFR-1 inhibition with D16F7 mAb might be a suitable adjunct therapy for VEGFR-1 positive tumours with acquired resistance to vemurafenib.

Targeting the vascular endothelial growth factor receptor-1 by the monoclonal antibody D16F7 to increase the activity of immune checkpoint inhibitors against cutaneous melanoma.

The vascular endothelial growth factor receptor-1 (VEGFR-1) is a membrane receptor for VEGF-A, placenta growth factor (PlGF) and VEGF-B that plays a crucial role in melanoma invasiveness, vasculogenic mimicry and tumor-associated angiogenesis. Furthermore, activation of VEGFR-1 is involved in the mobilization of myeloid progenitors from the bone marrow that infiltrate the tumor. Myeloid-derived suppressor cells and tumor-associated macrophages have been involved in tumor progression and resistance to cancer treatment with immune checkpoint inhibitors (ICIs). We have recently demonstrated that the anti-VEGFR-1 monoclonal antibody (mAb) D16F7 developed in our laboratories is able to inhibit melanoma growth in preclinical in vivo models and to reduce monocyte/macrophage progenitor mobilization and tumor infiltration by myeloid cells. Aim of the study was to investigate whether the anti-VEGFR-1 mAb D16F7 affects the activity of protumoral M2 macrophages in vitro in response to PlGF and inhibits the recruitment of these cells to the melanoma site in vivo. Finally, we tested whether, through its multi-targeted action, D16F7 mAb might increase the efficacy of ICIs against melanoma. The results indicated that VEGFR-1 expression is up-regulated in human activated M2 macrophages compared to activated M1 cells and exposure to the D16F7 mAb decreases in vitro chemotaxis of activated M2 macrophages. In vivo treatment with the anti-VEGFR-1 mAb D16F7 of B6D2F1 mice injected with syngeneic B16F10 melanoma cells resulted in tumor growth inhibition associated with the modification of tumor microenvironment that involves a decrease of melanoma infiltration by M2 macrophages and PD-1+ and FoxP3+ cells. These alterations result in increased M1/M2 and CD8+/FoxP3+ ratios, which favor an antitumor and immunostimulating milieu. Accordingly, D16F7 mAb increased the antitumor activity of the ICIs anti-CTLA-4 and anti-PD-1 mAbs. Overall, these data reinforce the role of VEGFR-1-mediated-signalling as a valid target for reducing tumor infiltration by protumoral macrophages and for improving the efficacy of immunotherapy with ICIs.

Melanoma and Vitiligo: In Good Company.

Cutaneous melanoma represents the most aggressive form of skin cancer, whereas vitiligo is an autoimmune disorder that leads to progressive destruction of skin melanocytes. However, vitiligo has been associated with cutaneous melanoma since the 1970s. Most of the antigens recognized by the immune system are expressed by both melanoma cells and normal melanocytes, explaining why the autoimmune response against melanocytes that led to vitiligo could be also present in melanoma patients. Leukoderma has been also observed as a side effect of melanoma immunotherapy and has always been associated with a favorable prognosis. In this review, we discuss several characteristics of the immune system responses shared by melanoma and vitiligo patients, as well as the significance of occurrence of leukoderma during immunotherapy, with special attention to check-point inhibitors.

Loss of miR-204 expression is a key event in melanoma.

Cutaneous melanoma (CM) is a malignancy with increasing occurrence. Its microRNA repertoire has been defined in a number studies, leading to candidates for biological and clinical relevance: miR-200a/b/c, miR-203, miR-205, miR-204, miR-211, miR-23b and miR-26a/b. Our work was aimed to validate the role of these candidate miRNAs in melanoma, using additional patients cohorts and in vitro cultures. miR-26a, miR-204 and miR-211 were more expressed in normal melanocytes, while miR-23b, miR-200b/c, miR-203 and miR-205 in epidermis and keratinocytes. None of the keratinocyte-related miRNAs was associated with any known mutation or with clinical covariates in melanoma. On the other hand, the loss of miR-204 was enriched in melanomas with NRAS sole mutation (Fisher exact test, P = 0.001, Log Odds = 1.67), and less frequent than expected in those harbouring CDKN2A mutations (Fisher exact test, P = 0.001, Log Odds - 1.09). Additionally, miR-204 was associated with better prognosis in two independent melanoma cohorts and its exogenous expression led to growth impairment in melanoma cell lines. Thus, miR-204 represents a relevant mechanism in melanoma, with potential prognostic value and its loss seems to act in the CDKN2A pathway, in cooperation with NRAS.

Cilengitide downmodulates invasiveness and vasculogenic mimicry of neuropilin 1 expressing melanoma cells through the inhibition of αvß5 integrin.

During melanoma progression, tumour cells show increased adhesiveness to the vascular wall, invade the extracellular matrix (ECM) and frequently form functional channels similar to vascular vessels (vasculogenic mimicry). These properties are mainly mediated by the interaction of integrins with ECM components. Since we had previously identified neuropilin 1 (NRP-1), a coreceptor of vascular endothelial growth factor A (VEGF-A), as an important determinant of melanoma aggressiveness, aims of this study were to identify the specific integrins involved in the highly invasive phenotype of NRP-1 expressing cells and to investigate their role as targets to counteract melanoma progression. Melanoma aggressiveness was evaluated in vitro as cell ability to migrate through an ECM layer and to form tubule-like structures using transfected cells. Integrins relevant to these processes were identified using specific blocking antibodies. The αvß5 integrin was found to be responsible for about 80% of the capability of NRP-1 expressing cells to adhere on vitronectin. In these cells αvß5 expression level was twice higher than in low-invasive control cells and contributed to the ability of melanoma cells to form tubule-like structures on matrigel. Cilengitide, a potent inhibitor of αν integrins activation, reduced ECM invasion, vasculogenic mimicry and secretion of VEGF-A and metalloproteinase 9 by melanoma cells. In conclusion, we demonstrated that ανß5 integrin is involved in the highly aggressive phenotype of melanoma cells expressing NRP-1. Moreover, we identified a novel mechanism that contributes to the antimelanoma activity of the αv integrin inhibitor cilengitide based on the inhibition of vasculogenic mimicry.

XPF protein levels determine sensitivity of malignant melanoma cells to oxaliplatin chemotherapy: suitability as a biomarker for patient selection.

As the options for systemic treatment of malignant melanoma (MM) increase, the need to develop biomarkers to identify patients who might benefit from cytotoxic chemotherapy becomes more apparent. In preclinical models, oxaliplatin has activity in cisplatin-resistant cells. In this study, we have shown that oxaliplatin forms interstrand crosslinks (ICLs) in cellular DNA and that loss of the heterodimeric structure-specific endonuclease XPF-ERCC1 causes hypersensitivity to oxaliplatin in mammalian cells. XPF deficiency resulted in late S-phase arrest and persistence of double-strand breaks following oxaliplatin treatment. In a panel of 12 MM cell lines, oxaliplatin sensitivity correlated with XPF and ERCC1 protein levels. The knockdown of ERCC1 and XPF protein levels by RNA interference increased sensitivity of cancer cells to oxaliplatin; overexpression of exogenous ERCC1 significantly decreased drug sensitivity. Following immunohistochemical optimization, XPF protein levels were quantified in MM tissue samples from 183 patients, showing variation in expression and no correlation with prognosis. In 57 patients with MM treated with cisplatin or carboplatin, XPF protein levels did not predict the likelihood of clinical response. We propose that oxaliplatin should not be discarded as a potential treatment for MM on the basis of the limited activity of cisplatin in unselected patients. Moreover, we show that XPF-ERCC1 protein levels are a key determinant of the sensitivity of melanoma cells to oxaliplatin in vitro. Immunohistochemical detection of XPF appears suitable for development as a tissue biomarker for potentially selecting patients for oxaliplatin treatment in a prospective clinical trial.

The potential impact of dietary choices on melanoma risk: an anti-inflammatory diet.

The role of inflammation in the aetiology of cancer is recognized. However, no study yet examined the association between an anti-inflammatory diet and cutaneous melanoma and explored whether it could be modified by genetic variations in cyclooxygenase-2 (COX-2), a key enzyme in inflammation. A case-control study was conducted in the IDI-IRCCS hospital in Rome, Italy with 273 cases of primary cutaneous melanoma and 269 controls frequency matched to cases. Information on socio-demographic and pigmentary characteristics, medical history, sun exposure and dietary habits were collected for all subjects. The - 765G > C polymorphism was identified in DNA extracted from blood samples. An anti-inflammatory diet score was created. Logistic regression models were fitted to obtain odds ratios (ORs) and 95% confidence intervals (CIs). A high anti-inflammatory diet score (≥ 8 anti-inflammatory dietary items) was associated with a decreased risk of cutaneous melanoma (OR: 0.29; 95%CI: 0.17-0.49, Ptrend < 0.0001) after adjusting for sex, age, education, number of common nevi, skin photo-type, solar lentigines and sunburns in childhood. COX-2 -765 G > C polymorphism was not an independent risk factor for cutaneous melanoma. Although interaction between - 765G > C genotypes and anti-inflammatory diet score was not statistically significant (p = 0.25), when stratified by -765 G > C genotypes the effect of the anti-inflammatory diet was slightly more pronounced for participants carrying - 765GG (OR: 0.17; 95%CI: 0.06-0.47, Ptrend < 0.001). Our study findings suggest that adherence to an anti-inflammatory diet is associated with a decreased risk of developing cutaneous melanoma. These results suggest the potential impact of dietary choices on melanoma risk.

Pharmacological inhibition of PDGF-C/neuropilin-1 interaction: A novel strategy to reduce melanoma metastatic potential.

Activation of neuropilin-1 (NRP-1) by platelet derived growth factor (PDGF)-C sustains melanoma invasiveness. Therefore, in the search of novel agents capable of reducing melanoma spreading, PDGF-C/NRP-1 interaction was investigated as a potential druggable target. Since the PDGF-C region involved in NRP-1 binding is not yet known, based on the sequence and structural homology between PDGF-C and vascular endothelial growth factor-A (VEGF-A), we hypothesized that the NRP-1 b1 domain region involved in the interaction with VEGF-A might also be required for PDGF-C binding. Hence, this region was selected from the protein crystal structure and used as target in the molecular docking procedure. In the following virtual screening, compounds from a DrugBank database were used as query ligands to identify agents potentially capable of disrupting NRP-1/PDGF-C interaction. Among the top 45 candidates with the highest affinity, five drugs were selected based on the safety profile, lack of hormonal effects, and current availability in the market: the antipsychotic pimozide, antidiabetic gliclazide, antiallergic cromolyn sodium, anticancer tyrosine kinase inhibitor entrectinib, and antihistamine azelastine. Analysis of drug influence on PDGF-C in vitro binding to NRP-1 and PDGF-C induced migration of human melanoma cells expressing NRP-1, indicated gliclazide and entrectinib as the most specific agents that were active at clinically achievable and non-toxic concentrations. Both drugs also reverted PDGF-C ability to stimulate extracellular matrix invasion by melanoma cells resistant to BRAF inhibitors. The inhibitory effect on tumor cell motility involved a decrease of p130Cas phosphorylation, a signal transduction pathway activated by PDGF-C-mediated stimulation of NRP-1.

NF-κB is activated in response to temozolomide in an AKT-dependent manner and confers protection against the growth suppressive effect of the drug.

BACKGROUND: Most DNA-damaging chemotherapeutic agents activate the transcription factor nuclear factor κB (NF-κB). However, NF-κB activation can either protect from or contribute to the growth suppressive effects of the agent. We previously showed that the DNA-methylating drug temozolomide (TMZ) activates AKT, a positive modulator of NF-κB, in a mismatch repair (MMR) system-dependent manner. Here we investigated whether NF-κB is activated by TMZ and whether AKT is involved in this molecular event. We also evaluated the functional consequence of inhibiting NF-κB on tumor cell response to TMZ. METHODS: AKT phosphorylation, NF-κB transcriptional activity, IκB-α degradation, NF-κB2/p52 generation, and RelA and NF-κB2/p52 nuclear translocation were investigated in TMZ-treated MMR-deficient (HCT116, 293TLα-) and/or MMR-proficient (HCT116/3-6, 293TLα+, M10) cells. AKT involvement in TMZ-induced activation of NF-κB was addressed in HCT116/3-6 and M10 cells transiently transfected with AKT1-targeting siRNA or using the isogenic MMR-proficient cell lines pUSE2 and KD12, expressing wild type or kinase-dead mutant AKT1. The effects of inhibiting NF-κB on sensitivity to TMZ were investigated in HCT116/3-6 and M10 cells using the NF-κB inhibitor NEMO-binding domain (NBD) peptide or an anti-RelA siRNA. RESULTS: TMZ enhanced NF-κB transcriptional activity, activated AKT, induced IκB-α degradation and RelA nuclear translocation in HCT116/3-6 and M10 but not in HCT116 cells. In M10 cells, TMZ promoted NF-κB2/p52 generation and nuclear translocation and enhanced the secretion of IL-8 and MCP-1. TMZ induced RelA nuclear translocation also in 293TLα+ but not in 293TLα- cells. AKT1 silencing inhibited TMZ-induced IκB-α degradation and NF-κB2/p52 generation. Up-regulation of NF-κB transcriptional activity and nuclear translocation of RelA and NF-κB2/p52 in response to TMZ were impaired in KD12 cells. RelA silencing in HCT116/3-6 and M10 cells increased TMZ-induced growth suppression. In M10 cells NBD peptide reduced basal NF-κB activity, abrogated TMZ-induced up-regulation of NF-κB activity and increased sensitivity to TMZ. In HCT116/3-6 cells, the combined treatment with NBD peptide and TMZ produced additive growth inhibitory effects. CONCLUSION: NF-κB is activated in response to TMZ in a MMR- and AKT-dependent manner and confers protection against drug-induced cell growth inhibition. Our findings suggest that a clinical benefit could be obtained by combining TMZ with NF-κB inhibitors.

Genetically Driven CD39 Expression Affects Sezary Cell Viability and IL-2 Production and Detects Two Patient Subsets with Distinct Prognosis.

Sézary syndrome (SS) is a rare and aggressive variant of cutaneous T-cell lymphoma. It is characterized by the copresence of CD4+ neoplastic lymphocytes, named Sezary cells, mainly in the blood, lymph nodes, and skin where they induce chronic inflammation that in turn impairs the patient's QOL and fuels neoplastic cells. SS is not readily cured, but immunotherapy is becoming an effective option for this lymphoma. In this study, we investigated, in a large cohort of patients with SS, the expression and function of the immune checkpoint molecule CD39, which degrades proinflammatory extracellular adenosine triphosphate. We showed that the SNP rs10748643 A/G within the ENTPD1 gene coding for the CD39 protein controls its expression level. Patients carrying the A/G‒G/G genotype showed a significantly higher frequency of clonal CD4+CD39+ SS cells than those carrying the A/A genotype. Different from other cancers, high CD39 expression correlates with a better prognosis. Comparing primary G/G with A/A lymphoma cells, we observed that G/G SS cells have a higher ability to degrade adenosine triphosphate, increased apoptotic susceptibility, and upon activation, reduced IL-2 production. Accordingly, CD39 enzymatic inhibition enhances SS cell viability and IL-2 production on activation. These results strongly suggest a special caution for SS treatment with therapeutic inhibitors of CD39.

Vitiligo-specific soluble biomarkers as early indicators of response to immune checkpoint inhibitors in metastatic melanoma patients.

Immunotherapy with checkpoint inhibitors (CPIs) strongly improved the outcome of metastatic melanoma patients. However, not all the patients respond to treatment and identification of prognostic biomarkers able to select responding patients is currently of outmost importance. Considering that development of vitiligo-like depigmentation in melanoma patients represents both an adverse event of CPIs and a favorable prognostic factor, we analyzed soluble biomarkers of vitiligo to validate them as early indicators of response to CPIs. Fifty-seven metastatic melanoma patients receiving CPIs were enrolled and divided according to the best overall response to treatment. Patient sera were evaluated at pre-treatment and after 1 and 3 months of therapy. We found that basal CD25 serum levels were higher in stable and responding patients and remained higher during the first 3 months of CPI therapy compared to non-responders. CXCL9 was absent in non-responding patients before therapy beginning. Moreover, an increase of CXCL9 levels was observed at 1 and 3 months of therapy for all patients, although higher CXCL9 amounts were present in stable and responding compared to non-responding patients. Variations in circulating immune cell subsets was also analyzed, revealing a reduced number of regulatory T lymphocytes in responding patients. Altogether, our data indicate that a pre-existing and maintained activation of the immune system could be an indication of response to CPI treatment in melanoma patients.

Vitiligo-like leukoderma as an indicator of clinical response to immune checkpoint inhibitors in late-stage melanoma patients.

PURPOSE: Although development of immune checkpoint inhibitors has revolutionized the treatment of metastatic melanoma, more than a half of treated patients experience disease progression during therapy. Cases of spontaneous vitiligo-like leukoderma have been described in melanoma patients and have been associated with a favorable outcome. This vitiligo-like leukoderma can also appear in melanoma patients undergoing immune therapies such as immune checkpoint inhibitors. However, no consensus exists about the relationship between vitiligo-like leukoderma onset and improved overall survival. Our study investigates the possible association between the onset of vitiligo-like leukoderma during immune checkpoint inhibitor treatment and a better prognosis. METHODS: A non-concurrent cohort study was conducted by identifying retrospectively 280 patients who had inoperable or metastatic melanoma and had undergone immune therapy with checkpoint inhibitors in any line of treatment. Toxicities developed during therapy were evaluated. RESULTS: Among the 280 study participants, 50% developed at least one type of toxicity, and vitiligo-like leukoderma was observed in 43 patients (15.4%). In the multivariate Cox model, a protective effect for mortality was observed for patients with vitiligo-like leukoderma development (HR : 0.23; 95% CI 0.11-0.44, p < 0.0001). In a sub-group analysis comprising only cutaneous melanoma in first line of treatment (N = 153), occurrence of vitiligo-like leukoderma was also an independent predictor factor for duration of clinical benefits measured by time to the next treatment (HR: 0.17; 95% CI 0.06-0.44). CONCLUSION: Our findings indicate that onset of vitiligo-like leukoderma during melanoma treatment could be a marker of favorable outcome in patients treated with immune checkpoint inhibitors.

Circulating miR-1246 and miR-485-3p as Promising Biomarkers of Clinical Response and Outcome in Melanoma Patients Treated with Targeted Therapy.

Despite the significant improvements in advanced melanoma therapy, there is still a pressing need for biomarkers that can predict patient response and prognosis, and therefore support rational treatment decisions. Here, we investigated whether circulating miRNAs could be biomarkers of clinical outcomes in patients treated with targeted therapy. Using next-generation sequencing, we profiled plasma miRNAs at baseline and at progression in patients treated with BRAF inhibitors (BRAFi) or BRAFi + MEKi. Selected miRNAs associated with response to therapy were subjected to validation by real-time quantitative RT-PCR. Receiver Operating Characteristics (ROC), Kaplan-Meier and univariate and multivariate Cox regression analyses were performed on the validated miR-1246 and miR-485-3p baseline levels. The median baseline levels of miR-1246 and miR-485-3p were significantly higher and lower, respectively, in the group of patients not responding to therapy (NRs) as compared with the group of responding patients (Rs). In Rs, a trend toward an increase in miR-1246 and a decrease in miR-485-3p was observed at progression. Baseline miR-1246 level and the miR-1246/miR-485-3p ratio showed a good ability to discriminate between Rs and NRs. Poorer PFS and OS were observed in patients with unfavorable levels of at least one miRNA. In multivariate analysis, a low level of miR-485-3p and a high miR-1246/miR-485-3p ratio remained independent negative prognostic factors for PFS, while a high miR-1246/miR-485-3p ratio was associated with an increased risk of mortality, although statistical significance was not reached. Evaluation of miR-1246 and miR-485-3p baseline plasma levels might help clinicians to identify melanoma patients most likely to be unresponsive to targeted therapy or at higher risk for short-term PFS and mortality, thus improving their management.

Exogenous control of the expression of Group I CD1 molecules competent for presentation of microbial nonpeptide antigens to human T lymphocytes.

Group I CD1 (CD1a, CD1b, and CD1c) glycoproteins expressed on immature and mature dendritic cells present nonpeptide antigens (i.e., lipid or glycolipid molecules mainly of microbial origin) to T cells. Cytotoxic CD1-restricted T lymphocytes recognizing mycobacterial lipid antigens were found in tuberculosis patients. However, thanks to a complex interplay between mycobacteria and CD1 system, M. tuberculosis possesses a successful tactic based, at least in part, on CD1 downregulation to evade CD1-dependent immunity. On the ground of these findings, it is reasonable to hypothesize that modulation of CD1 protein expression by chemical, biological, or infectious agents could influence host's immune reactivity against M. tuberculosis-associated lipids, possibly affecting antitubercular resistance. This scenario prompted us to perform a detailed analysis of the literature concerning the effect of external agents on Group I CD1 expression in order to obtain valuable information on the possible strategies to be adopted for driving properly CD1-dependent immune functions in human pathology and in particular, in human tuberculosis.

Polymorphisms of GSTM1 and GSTT1, sun exposure and the risk of melanoma: a case-control study.

Glutathione S-transferases (GSTs) are a family of enzymes that are known to play an important role in cellular protection against oxidative stress, including the oxidative stress caused by ultraviolet radiation. This study focused on the possible involvement of GSTM1 and GSTT1 polymorphisms in risk modulation of cutaneous melanoma. Within a case-control study, the presence of the null polymorphism at GSTM1 and GSTT1 was investigated in 188 cases of cutaneous melanoma and 152 controls. Information on socio-demographic characteristics, medical history, sun exposure and pigmentary characteristics were collected for all subjects. Logistic regression was used to estimate odds ratio (OR) and 95% confidence intervals (CI). An interaction was suggested between the GSTM1 and GSTT1 "null" genotype and episodes of sunburn in childhood OR of interaction (1.65, 95% CI (95% CI) 0.27-9.94). The risk of melanoma among the subset of participants who reported sunburns in childhood and who had both null variants, was nine (OR 9.16; 95% CI 1.18-70.9). The results suggest that subjects carrying both GSTM1 and GSTT1 null polymorphisms and experiencing sunburns in childhood have an extremely high risk of melanoma.

Melanoma Cell Resistance to Vemurafenib Modifies Inter-Cellular Communication Signals.

The therapeutic success of BRAF inhibitors (BRAFi) and MEK inhibitors (MEKi) in BRAF-mutant melanoma is limited by the emergence of drug resistance, and several lines of evidence suggest that changes in the tumor microenvironment can play a pivotal role in acquired resistance. The present study focused on secretome profiling of melanoma cells sensitive or resistant to the BRAFi vemurafenib. Proteomic and cytokine/chemokine secretion analyses were performed in order to better understand the interplay between vemurafenib-resistant melanoma cells and the tumor microenvironment. We found that vemurafenib-resistant melanoma cells can influence dendritic cell (DC) maturation by modulating their activation and cytokine production. In particular, human DCs exposed to conditioned medium (CM) from vemurafenib-resistant melanoma cells produced higher levels of pro-inflammatory cytokines-that potentially facilitate melanoma growth-than DCs exposed to CM derived from parental drug-sensitive cells. Bioinformatic analysis performed on proteins identified by mass spectrometry in the culture medium from vemurafenib-sensitive and vemurafenib-resistant melanoma cells suggests a possible involvement of the proteasome pathway. Moreover, our data confirm that BRAFi-resistant cells display a more aggressive phenotype compared to parental ones, with a significantly increased production of interferon-γ, interleukin-8, vascular-endothelial growth factor, CD147/basigin, and metalloproteinase 2 (MMP-2). Plasma levels of CD147/basigin and MMP-2 were also measured before the start of therapy and at disease progression in a small group of melanoma patients treated with vemurafenib or vemurafenib plus cobimetinib. A significant increment in CD147/basigin and MMP-2 was observed in all patients at the time of treatment failure, strengthening the hypothesis that CD147/basigin might play a role in BRAFi resistance.