Nicotinamide Phosphoribosyltransferase (NAMPT) as a Therapeutic Target in BRAF-Mutated Metastatic Melanoma

Background: One of the effects of oncogenic signaling is metabolic reprogramming of tumor cells to support anabolic growth, opening the way to therapeutic targeting of metabolic pathways. Methods: We studied NAD biosynthesis in BRAF inhibitor (BRAFi)-resistant (BiR) melanoma cell lines. Data in cell lines were confirmed by immunohistochemistry in biopsies from 17 patients with metastatic melanoma (MM) before and after the acquisition of resistance to BRAFi. Therapeutic potential of NAD biosynthesis inhibitors was determined by in vitro monitoring cell growth and death and in mouse xenograft models. Mice (n=6-10 mice/group) were treated with nicotinamide phosphoribosyltranferase inhibitor (NAMPTi), BRAFi, or their combination, and tumor growth and survival were analyzed. All statistical tests were two-sided. Results: BiR cells had higher NAD levels compared with their BRAFi-sensitive counterparts (P < .001 and P = .001 for M14 and A375, respectively) and with normal melanocytes (P<.001), achieved through transcriptional upregulation of the enzyme NAMPT, which became the master regulator of NAD synthesis. Conversely, treatment with BRAFi or MEK inhibitors decreased NAMPT expression and cellular NAD levels. Robust NAMPT upregulation was documented in tissue biopsies from MM patients after development of resistance to BRAFi (P < .001). Treatment of melanoma cells with NAMPTi depleted NAD and ATP, depolarized mitochondrial membrane, and led to reactive oxygen species production, blocking cells in the G2/M phase and inducing apoptosis. Treatment of BiR xenografts with NAMPTi improved mouse survival (median survival of vehicletreated mice was 52 days vs 100 days for NAMPTi-treated ones in M14/BiR, while in A375/BiR median survival of vehicletreated mice was 23.5 days vs 43 days for NAMPTi-treated ones, P < .001). Conclusions: BiR melanoma cells overexpress NAMPT, which acts as a connecting element between BRAF oncogenic signaling and metabolism, becoming an actionable target for this subset of MM patients

PD-L1 up-regulation in melanoma increases disease aggressiveness and is mediated through miR-17-5p

PD-L1 is expressed by a subset of patients with metastatic melanoma (MM) with an unfavorable outcome. Its expression is increased in cells resistant to BRAF or MEK inhibitors (BRAFi or MEKi). However, the function and regulation of expression of PD-L1 remain incompletely understood. After generating BRAFi- and MEKi-resistant cell lines, we observed marked up-regulation of PD-L1 expression. These cells were characterized by a common gene expression profile with up-regulation of genes involved in cell movement. Consistently, in vitro they showed significantly increased invasive properties. This phenotype was controlled in part by PD-L1, as determined after silencing the molecule. Up-regulation of PD-L1 was due to post-transcriptional events controlled by miR-17-5p, which showed an inverse correlation with PD-L1 mRNA. Direct binding between miR-17-5p and the 3’-UTR of PD-L1 mRNA was demonstrated using luciferase reporter assays. In a cohort of 80 BRAF-mutated MM patients treated with BRAFi or MEKi, constitutive expression of PD-L1 in the absence of immune infiltrate, defined the patient subset with the worst prognosis. Furthermore, PD-L1 expression increased in tissue biopsies after the metastatic lesions became resistant to BRAFi or MEKi. Lastly, plasmatic miR-17-5p levels were higher in patients with PD-L1(+) than PD-L1(-) lesions. In conclusion, our findings indicate that PD-L1 expression induces a more aggressive behavior in melanoma cells. We also show that PD-L1 up-regulation in BRAFi or MEKi-resistant cells is partly due to post-transcriptional mechanisms that involve miR-17-5p, suggesting that miR-17-5p may be used as a marker of PD-L1 expression by metastatic lesions and ultimately a predictor of responses to BRAFi or MEKi

Nicotinamide Phosphoribosyltransferase (NAMPT) as a Therapeutic Target in BRAF-Mutated Metastatic Melanoma.

Background: One of the effects of oncogenic signaling is metabolic reprogramming of tumor cells to support anabolic growth, opening the way to therapeutic targeting of metabolic pathways. Methods: We studied NAD biosynthesis in BRAF inhibitor (BRAFi)–resistant (BiR) melanoma cell lines. Data in cell lines were confirmed by immunohistochemistry in biopsies from 17 patients with metastatic melanoma (MM) before and after the acquisition of resistance to BRAFi. Therapeutic potential of NAD biosynthesis inhibitors was determined by in vitro monitoring cell growth and death and in mouse xenograft models. Mice (n 1⁄4 6–10 mice/group) were treated with nicotinamide phosphoribosyltranferase inhibitor (NAMPTi), BRAFi, or their combination, and tumor growth and survival were analyzed. All statistical tests were two-sided. Results: BiR cells had higher NAD levels compared with their BRAFi-sensitive counterparts (P < .001 and P 1⁄4 .001 for M14 and A375, respectively) and with normal melanocytes (P < .001), achieved through transcriptional upregulation of the enzyme NAMPT, which became the master regulator of NAD synthesis. Conversely, treatment with BRAFi or MEK inhibitors decreased NAMPT expression and cellular NAD levels. Robust NAMPT upregulation was documented in tissue biopsies from MM patients after development of resistance to BRAFi (P < .001). Treatment of melanoma cells with NAMPTi depleted NAD and ATP, depolarized mitochondrial membrane, and led to reactive oxygen species production, blocking cells in the G2/M phase and inducing apoptosis. Treatment of BiR xenografts with NAMPTi improved mouse survival (median survival of vehicle- treated mice was 52 days vs 100 days for NAMPTi-treated ones in M14/BiR, while in A375/BiR median survival of vehicle- treated mice was 23.5 days vs 43 days for NAMPTi-treated ones, P < .001). Conclusions: BiR melanoma cells overexpress NAMPT, which acts as a connecting element between BRAF oncogenic signaling and metabolism, becoming an actionable target for this subset of MM patients

The preventive health professions in Italy. The efficient use of resources, skills and best practice during the pandemic

Health visitors (HVs) and environmental health officers (EHOs) are the healthcare workers (HCWs) who, in the Italian National Health Service, mainly operate in the prevention departments of local health authorities, guaranteeing the territorial activities specifically declared with the respective professional profiles. During the SARS-CoV-2 pandemic, it was necessary to reallocate all HCWs supporting Hygiene and Public Health Services involved on the front lines of the emergency, in order to perform preventive activities and to take immediate action to fight the spread of the virus. By means of an IT survey consisting of three sections, this study investigated how 960 HVs and EHOs dealt with this reallocation, with the shifting in service assignment, and with the perceived level of fatigue and pressure, through the application of skills acquired from university training. The synergy among the preventive health professions, the ability to work in a multi-professional team, and the complementary training of HCWs represent the main strengths for overcoming future public health challenges, aimed at protecting human health

Problematic social media use: Associations with health complaints among adolescents

Objective. Problematic Social Media Use (PSMU) has an addictive potential for young users. The aim of this study was to show the prevalence of PSMU across Italian regions and its association with health complaints. Materials and methods. Data are gathered from the Italian 2018 Health Behaviour in School-aged Children survey using a representative sample of Italian adolescents aged 11, 13 and 15 years (50.6% males). Participants completed self-administered questionnaires assessing PSMU and health complaints. Results. PSMU affects 8.9% adolescents in Italy and the prevalence is quite consistent across regions. 13-year-olds girls showed the highest percentage of PSMU (13%). Problematic users of social media are more likely to report multiple somatic (OR = 1.84 [95% CI 1.82-1.85]) and psychological (OR = 2.60 [95% CI 2.58-2.63]) symptoms. Conclusions. PSMU represents a widespread problem in Italy. National prevention interventions are needed in order to promote a positive use of social media