Identification of Overexpressed Genes in Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is a fatal tumor lacking effective therapies. The characterization of overexpressed genes could constitute a strategy for identifying drivers of tumor progression as targets for novel therapies. Thus, we performed an integrated gene-expression analysis on RNAseq data of 85 MPM patients from TCGA dataset and reference samples from the GEO. The gene list was further refined by using published studies, a functional enrichment analysis, and the correlation between expression and patients' overall survival. Three molecular signatures defined by 15 genes were detected. Seven genes were involved in cell adhesion and extracellular matrix organization, with the others in control of the mitotic cell division or apoptosis inhibition. Using Western blot analyses, we found that ADAMTS1, PODXL, CIT, KIF23, MAD2L1, TNNT1, and TRAF2 were overexpressed in a limited number of cell lines. On the other hand, interestingly, CTHRC1, E-selectin, SPARC, UHRF1, PRSS23, BAG2, and MDK were abundantly expressed in over 50% of the six MPM cell lines analyzed. Thus, these proteins are candidates as drivers for sustaining the tumorigenic process. More studies with small-molecule inhibitors or silencing RNAs are fully justified and need to be undertaken to better evaluate the cancer-driving role of the targets herewith identified.

BAG2, MAD2L1, and MDK are cancer-driver genes and candidate targets for novel therapies in malignant pleural mesothelioma.

Malignant pleural mesothelioma (MPM) is an aggressive cancer with a poor prognosis and the identification of novel druggable targets is urgently needed. In previous work, we identified 15 deregulated genes highly expressed in MPM tissues and correlated with a poor prognosis. Here, we validated these findings on an independent dataset of 211 MPM patients (EGA, EGAD00001001915) and on a panel of MPM cell lines. Furthermore, we carried out in vitro gene silencing followed by proliferation, cytotoxicity, caspase, and migration assays to define whether these targets could be cancer-driver genes. We ended up with three novel candidates (i.e., BAG2, MAD2L1, and MDK), whose encoded proteins could be exploited as druggable targets. Moreover, of novelty, immunohistochemistry analysis on tissues revealed that the overexpression of BAG2 and MAD2L1 could differentiate MPM from RMP patients. Furthermore, when we tested Neratinib (an inhibitor of MAD2L1) and iMDK (an inhibitor of MDK) we found that they are effective on MPM cells, in part phenocopying the effects of MAD2L1 and MDK gene silencing. In summary, in the present work, we report that BAG2, MAD2L1, and MDK are bona fide cancer-driver genes for MPM worth of further studies.

The landscape of cancer-rewired GPCR signaling axes.

We explored the dysregulation of G-protein-coupled receptor (GPCR) ligand systems in cancer transcriptomics datasets to uncover new therapeutics opportunities in oncology. We derived an interaction network of receptors with ligands and their biosynthetic enzymes. Multiple GPCRs are differentially regulated together with their upstream partners across cancer subtypes and are associated to specific transcriptional programs and to patient survival patterns. The expression of both receptor-ligand (or enzymes) partners improved patient stratification, suggesting a synergistic role for the activation of GPCR networks in modulating cancer phenotypes. Remarkably, we identified many such axes across several cancer molecular subtypes, including many involving receptor-biosynthetic enzymes for neurotransmitters. We found that GPCRs from these actionable axes, including, e.g., muscarinic, adenosine, 5-hydroxytryptamine, and chemokine receptors, are the targets of multiple drugs displaying anti-growth effects in large-scale, cancer cell drug screens, which we further validated. We have made the results generated in this study freely available through a webapp (gpcrcanceraxes.bioinfolab.sns.it).