Pablo Reclusa

Exosomal microRNAs in liquid biopsies: future biomarkers for prostate cancer

Prostate cancer is the second most diagnosed cancer in males in the world. Plasma quantification of prostate-specific antigen substantially improved the early detection of prostate cancer, but still lacks the required specificity. Clinical management of prostate cancer needs advances in the development of new non-invasive biomarkers, ameliorating current diagnosis and prognosis and guiding therapeutic decisions. microRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression at the post-transcriptional level. These miRNAs are expressed in the cells and are also present in cell-derived extracellular vesicles such as exosomes. Exosomes have been shown to act as mediators for cell to cell communication because of the regulatory functions of their content. High levels of exosomes are found in several body fluids from cancer patients and could be a potential source of non-invasive biomarkers. In this review, we summarize the diagnostic and prognostic utility of exosomal miRNAs in prostate cancer.

FGFR a promising druggable target in cancer: Molecular biology and new drugs

INTRODUCTION The Fibroblast Growth Factor Receptor (FGFR) family consists of Tyrosine Kinase Receptors (TKR) involved in several biological functions. Recently, alterations of FGFR have been reported to be important for progression and development of several cancers. In this setting, different studies are trying to evaluate the efficacy of different therapies targeting FGFR. AREAS COVERED This review summarizes the current status of treatments targeting FGFR, focusing on the trials that are evaluating the FGFR profile as inclusion criteria: Multi-Target, Pan-FGFR Inhibitors and anti-FGF (Fibroblast Growth Factor)/FGFR Monoclonal Antibodies. EXPERT OPINION Most of the TKR share intracellular signaling pathways; therefore, cancer cells tend to overcome the inhibition of one tyrosine kinase receptor by activating another. The future of TKI (Tyrosine Kinase Inhibitor) therapy will potentially come from multi-targeted TKIs that target different TKR simultaneously. It is crucial to understand the interaction of the FGF-FGFR axis with other known driver TKRs. Based on this, it is possible to develop therapeutic strategies targeting multiple connected TKRs at once. One correct step in this direction is the reassessment of multi target inhibitors considering the FGFR status of the tumor. Another opportunity arises from assessing the use of FGFR TKI on patients harboring FGFR alterations.

Amphiregulin contained in NSCLC-exosomes induces osteoclast differentiation through the activation of EGFR pathway

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths worldwide. The majority of patients are diagnosed in advanced disease stage. Bone metastasis is the most frequent complication in NSCLC resulting in osteolytic lesions. The perfect balance between bone-resorbing osteoclasts and bone-forming osteoblasts activity is lost in bone metastasis, inducing osteoclastogenesis. In NSCLC, the epidermal growth factor receptor (EGFR) pathway is constitutively activated. EGFR binds Amphiregulin (AREG) that is overexpressed in several cancers such as colon, breast and lung. Its levels in plasma of NSCLC patients correlate with poor prognosis and AREG was recently found as a signaling molecule in exosomes derived from cancer cell lines. Exosomes have a key role in the cell-cell communication and they were recently indicated as important actors in metastatic niche preparation. In the present work, we hypothesize a role of AREG carried by exosomes derived from NSCLC in bone metastasis induction. We observed that NSCLC-exosomes, containing AREG, induce EGFR pathway activation in pre-osteoclasts that in turn causes an increased expression of RANKL. RANKL is able to induce the expression of proteolytic enzymes, well-known markers of osteoclastogenesis, triggering a vicious cycle in osteolytic bone metastasis.

Profile of the Roche cobas(®) EGFR mutation test v2 for non-small cell lung cancer.

ABSTRACT Introduction: The discovery of driver mutations in non-small cell lung cancer (NSCLC) has led to the development of genome-based personalized medicine. Fifteen to 20% of adenocarcinomas harbor an epidermal growth factor receptor (EGFR) activating mutation associated with responses to EGFR tyrosine kinase inhibitors (TKIs). Individual laboratories’ expertise and the availability of appropriate equipment are valuable assets in predictive molecular pathology, although the choice of methods should be determined by the nature of the samples to be tested and whether the detection of only well-characterized EGFR mutations or rather, of all detectable mutations, is required. Areas covered: The EGFR mutation testing landscape is manifold and includes both screening and targeted methods, each with their own pros and cons. Here we review one of these companion tests, the Roche cobas® EGFR mutation test v2, from a methodological point of view, also exploring its liquid-biopsy applications. Expert commentary: The Roche cobas® EGFR mutation test v2, based on real time RT-PCR, is a reliable option for testing EGFR mutations in clinical practice, either using tissue-derived DNA or plasma-derived cfDNA. This application will be valuable for laboratories with whose purpose is purely diagnostic and lacking high-throughput technologies.

Exosomes as diagnostic and predictive biomarkers in lung cancer

The concept of exosomes has evolved from be considered garbage bags to the demonstration that exosomes could play very interesting roles and functions, from biomarkers detection to the potential of work as drug delivery systems. It has been widely proved that exosomes can contain key molecules important for the tumour development. The current review summarizes the latest investigations developed in the field of predictive exosomal biomarkers. The microRNAs (miRNAs) are the more known molecules due to their amount inside the exosomes and the sensitivity of the techniques available for their study. However, exosomal proteins, RNA and DNA are becoming an interesting and more feasible field of study due to the improvement in the techniques available for their analysis. In the future years, it is hoped that exosomes will become an established member of the liquid biopsies in the clinical practice due to their diagnostic and prognostic properties.

Exosomes in lung cancer liquid biopsies: Two sides of the same coin?

The absence of suitable diagnostic, prognostic and predictive iomarkers for non-small cell lung cancer (NSCLC) and the limted efficacy of the available treatments are responsible of the ow survival rates of this disease. Conventional chemotherapy, in ombination with radiotherapy, has improved outcomes, but a ignificant proportion of NSCLC patients do not respond to these reatments [1]. The discovery of new molecular targets and drugs, s tyrosine-kinase inhibitors (TKIs) have led to the development f different generations of targeted therapies ameliorating clinial outcomes of the disease. But however, still nowadays there are o definitive treatments for NSCLC and the research of new nonnvasive early diagnostic and prognostic biomarkers is mandatory 2]. In this field, liquid biopsies, which include tumor components s circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) nd exosomes, could be the long awaited response to this tricky ask [3]. Exosomes, one of the lesser-known liquid biopsies components, re cell-derived nanovescicles (30–100 nm of diameter) firstly escribed studying reticulocyte differentiation [4]. Exosomes are ormed by the inward budding of multivesicular bodies (MVB), omponent of the endocytic pathway [5]. Exosomes are released rom different types of cells both under physiological and pathoogical conditions and, interestingly, have been well detected in everal body fluids, such as peripheral blood, urine, pleural effusion, mniotic fluid, saliva, breast-milk and cerebrospinal fluid [3,6]. hey function as messenger particles, playing a role in cell-to-cell ommunication and to deliver proteins, lipids, mRNAs and miRAs with biological activity in the target cells [3]. Now it is well nown that these vesicles have pleiotropic functions in remodelng the tumor microenvironment, promoting immune escape and n tumor progression [7]. In the last years, the molecular profiling of these nanovesicles in he plasma of patients with NSCLC, offered the opportunity to delinate better the characteristics of the disease. Exosomes released rom NSCLC patients contain proteins related to tumor growth and rogression, such as EGFR, claudins, K-ras and inducers of matrix etalloproteinase synthesis like EMMPRIN [8]. Similarly to these ndings, in other cancer types several exosomal proteins have been escribed with diagnostic and prognostic features, such as MIA nd S100B in melanoma and Glypican-1 in early pancreatic cancer 9,10]. So, these features might be exploited as a source of speific biomarkers because they reflect the pathological features of he disorder. Jakobsen et al. demonstrated the potential diagnosic properties of exosomal proteins in advanced NSCLC. Exosomes solated from plasma of 109 NSCLC patients (stage IIIa − IV) and 10 healthy controls were analyzed with an extracellular vesile array that phenotyped the exosomes directly from the plasma amples using 37 antibodies against lung cancer-related proteins,

Liquid Biopsy in Non-Small Cell Lung Cancer (NSCLC)

Lung cancer is the leading cause of cancer deaths worldwide. To date, the gold standard for the molecular analysis of a patient affected by NSCLC is the tissue biopsy. The discovery of activating mutations and rearrangements in specific genes has revolutionized the therapeutic approaches of lung cancer over the last years. For this reason, a strict “molecular follow-up” is mandatory to evaluate patient’s disease evolution. Indeed, liquid biopsy has raised as the “new ambrosia of researchers” as it could help clinicians to identify both prognostic and predictive biomarkers in a more accessible way. Liquid biopsy analysis can be used in different moments starting from diagnosis to relapse, earning multiple clinical meanings, offering thus a noninvasive but valid method to detect actionable mutations. Although the implementation of both exosomes and CTCs in clinical practice is several steps back, new advances and discoveries make them, together with the ctDNA, a very promising tool. In the following chapter we will discuss the recent advances of liquid biopsy in NSCLC highlighting the possible clinical utility of CTCs, ctDNA and exosomes.