G. Viscardi

Implication of the Hedgehog pathway in hepatocellular carcinoma

The prognosis for patients who are diagnosed with advanced stage hepatocellular carcinoma (HCC) is poor because there are few treatment options. Recent research has focused on the identification of novel molecular entities that can be targeted to inhibit oncogenic signals that are involved in the carcinogenesis, proliferation and progression of HCC. Among all of the pathways that are involved in the development of HCC, Hedgehog (HH) signalling has demonstrated a substantial role in hepatocarcinogenesis and HCC progression. HH plays a physiological role in embryogenesis, through the induction of the differentiation of hepatocytes from endodermal progenitors. The re-activation of the HH pathway in chronic damaged liver is a mechanism of fibrotic degeneration and is implicated in various stages of HCC development. HH activation sustains the sub-population of immature liver epithelial cells that are involved in the pathogenesis of cirrhosis and HCC, and HH itself is a mediator of the alcohol-derived malignant transformation of liver cells. High levels of expression of HH protein markers in liver tumour tissues are correlated with aggressive histological and biological features and a poor clinical outcome. In vitro and in vivo inhibition models of the HH pathway confirm that HH is essential in maintaining tumour growth, metastasis and a mesenchymal phenotype.

Results of the safety run-in part of the METAL (METformin in Advanced Lung cancer) study: a multicentre, open-label phase I–II study of metformin with erlotinib in second-line therapy of patients with stage IV non-small-cell lung cancer

Purpose Our previous works demonstrated the ability of metformin to revert resistance to gefitinib, a selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in non-small-cell lung cancer (NSCLC) EGFR/LKB1 wild-type (WT) cell lines. However, the optimal dose of metformin to be used in non-diabetic patients still remains to be defined. The phase I–II trial METformin in Advanced Lung cancer (METAL) was designed to identify the maximum tolerated dose and to evaluate safety and activity of metformin combined with erlotinib in second-line treatment of patients with stage IV NSCLC, whose tumours harbour the WT EGFR gene. Patients and methods We report results from the safety run-in part designed to detect acute toxicities, to study pharmacokinetics and to identify the recommended phase II dose (RPD) to be used for the following phase of the study. In the run-in phase, metformin treatment was administered according to a dose escalation scheme and, subsequently, combined with erlotinib. Results Twelve patients were enrolled. Common adverse events were diarrhoea, decreased appetite, abdominal pain, vomiting and skin toxicity, mostly reversible with symptomatic medical treatment. Dose-limiting toxicities were vomiting and diarrhoea registered in the initial cohort receiving metformin 2000 mg plus erlotinib at 150 mg die, which was declared the maximum administered dose. Only one of nine patients treated at the next lower dose of 1500 mg of metformin plus erlotinib at 150 mg experienced G3 gastrointestinal toxicity. Metformin plasma-concentration profile confirmed the trend already observed in non-diabetic population. Glycemic profiles showed stability of the blood glucose level within the physiological range for non-diabetic subjects. At a follow-up of 30 weeks, six (50%) patients experienced a disease control (5 SD and 1 partial response). Conclusions The RP2D of metformin dose was defined at 1500 mg/day to be combined with erlotinib 150 mg. Trial registration number EudraCT number: 2014-000349-59.

Clinical Approach: Recommendations for the Clinicians

Mediastinal masses include a wide variety of entities both neoplastic and not often presenting with several clinical and pathological features thus constituting a diagnostic challenge for clinicians.

Role and targeting of anaplastic lymphoma kinase in cancer

Anaplastic lymphoma kinase (ALK) gene activation is involved in the carcinogenesis process of several human cancers such as anaplastic large cell lymphoma, lung cancer, inflammatory myofibroblastic tumors and neuroblastoma, as a consequence of fusion with other oncogenes (NPM, EML4, TIM, etc) or gene amplification, mutation or protein overexpression.ALK is a transmembrane tyrosine kinase receptor that, upon ligand binding to its extracellular domain, undergoes dimerization and subsequent autophosphorylation of the intracellular kinase domain. When activated in cancer it represents a target for specific inhibitors, such as crizotinib, ceritinib, alectinib etc. which use has demonstrated significant effectiveness in ALK-positive patients, in particular ALK-positive non- small cell lung cancer.Several mechanisms of resistance to these inhibitors have been described and new strategies are underway to overcome the limitations of current ALK inhibitors.

51PD Effect of MEK inhibition on PDL1 and and on cytokinesproduction profilein NSCLC cell lines and in human lymphocites

Background: Preclinical models suggest that MAPK pathway is implicated in the immune-resistance of tumors and MEK-inhibition can increase the CD8+ T-cell infiltration and the efficacy of PD-1/PD-L1 blockade. Methods: First, we evaluated PD-L1 mRNA expression by Real Time qPCR and its protein production, togheter with MAPK proteins in a panel of non-small cell lung cancer (NSCLC) cell lines. Then, we studied the changes in PD-L1 and major histocompatibility complex class-I (MHC-I) expression and cytokines’ production, after inhibition with selumetinib or stimulation of MAPK signalling by phorbol 12-myristate 13-acetate (PMA). In addition, we explored the effect of MEK inhibition on T-cell function by using Peripheral blood mononuclear cells (PBMC) from healthy volunteers. Results: A consistent correlation between PD-L1 mRNA and protein expression across cell lines suggested that expression mainly depends on trascriptional regulation, and it is regulated by MAPK signal, through the bindng of p65 to the PD-L1 promoter. Moreover, MEK inhibition resulted in an increased expression of MHC-I on cancer cells and increased mRNA expression levels of IFN gamma, IL-6, IL-1B, and TNFalpha, all molecules involved in the activation and differentiation of TCD8+ cytotoxic lymphocytes (CTL) subset. In this scenario, we also tested the effect of MEK inhibitor on activated T-lymphocytes from PBMC of healthy volunteers. After five days of treatment, RT-qPCR analysis revealed a significant increase of mRNA expression of some typical CD8+ T cell pro-inflammatory cytokines, like IL-12, TNFalpha and IFNgamma. Conclusions: These results further support the idea that MEK inhibitor reduces PD-L1 expression and this allows the establishment of a pro inflammatory microenvironment. On the other side, pheripheral T cells, treated with selumetinib, produce pro inflammatory cytokines typical of CTL subset, that seems more involved in immune response against cancer. In this context, MEK inhibition may represent a potential mechanism to convert otherwise resistant cancers and suggest new potential treatment combination strategies of MEK-inhibitors with anti-PD-L1 antibodies in NSCLC. Legal entity responsible for the study: University of Campania “L. Vanvitelli” Funding: Has not received any funding Disclosure: All authors have declared no conflicts of interest.